JP6708161B2 - Ejector type refrigeration cycle - Google Patents

Description

The present invention relates to an ejector type refrigeration cycle including an ejector.

Conventionally, an ejector type refrigeration cycle which is a vapor compression type refrigeration cycle device including an ejector is known. In this type of ejector type refrigeration cycle, the pressure of the suction refrigerant sucked into the compressor can be increased by the pressurizing action of the diffuser portion of the ejector. As a result, in the ejector refrigeration cycle, the power consumption of the compressor can be reduced and the coefficient of performance (COP) of the cycle can be improved.

For example, Patent Document 1 discloses an ejector-type refrigeration cycle including two evaporators. More specifically, in the ejector-type refrigeration cycle of Patent Document 1, the refrigerant flowing out from the first evaporator on the side having a high refrigerant evaporation pressure is caused to flow into the nozzle portion of the ejector, and the second evaporation on the side having a low refrigerant evaporation pressure is performed. The refrigerant has a cycle configuration in which the refrigerant flowing out of the container is sucked from the refrigerant suction port of the ejector.

Further, the ejector-type refrigeration cycle of Patent Document 1 is provided with a liquid storage mechanism that stores the liquid phase refrigerant on the inlet side of the nozzle portion, and allows the gas-liquid two-phase refrigerant to flow into the nozzle portion. As a result, in the ejector-type refrigeration cycle of Patent Document 1, the condensation delay of the refrigerant in the nozzle part is suppressed, and the boosting capability in the diffuser part is suppressed from becoming unstable.

JP, 2005-1365, A

However, in the ejector-type refrigeration cycle of Patent Document 1, since the refrigerant that flows into the nozzle portion of the ejector is a gas-liquid two-phase refrigerant, it is difficult to aim for further improvement in COP. The reason is that if the refrigerant flowing into the nozzle portion is a gas-liquid two-phase refrigerant, it is difficult to increase the recovery energy of the ejector.

More specifically, a general ejector collects the loss of velocity energy when the refrigerant is depressurized by the nozzle portion by sucking the refrigerant from the refrigerant suction port by the suction action of the injected refrigerant. Then, the energy recovered (hereinafter referred to as recovered energy) is converted into pressure energy in the diffuser section, thereby boosting the pressure of the refrigerant. Therefore, in order to further improve the COP, it is effective to increase the amount of recovered energy.

Here, the recovered energy is the amount of decrease in the enthalpy of the refrigerant when the refrigerant is isentropically decompressed in the nozzle portion, that is, the amount of the injected refrigerant immediately after being injected from the enthalpy of the refrigerant flowing into the nozzle portion. It can be represented by the enthalpy difference obtained by subtracting the enthalpy. Further, the slope of the isentropic line on the Mollier diagram becomes smaller as the enthalpy of the refrigerant becomes higher.

Therefore, if the decompression amount in the nozzle portion is constant, the amount of recovered energy can be increased by increasing the enthalpy of the refrigerant flowing into the nozzle portion.

However, in the cycle in which the refrigerant flowing into the nozzle portion is a gas-liquid two-phase refrigerant like the ejector refrigeration cycle of Patent Document 1, the upper limit value of the enthalpy of the refrigerant flowing into the nozzle portion is determined, so the recovered energy The upper limit of quantity is also decided. Therefore, it is difficult to further improve the COP in the ejector refrigeration cycle of Patent Document 1.

The present invention has been made in view of the above points, and an object thereof is to sufficiently improve the coefficient of performance of an ejector-type refrigeration cycle in which a refrigerant flowing out of an evaporator is caused to flow into a nozzle portion of an ejector.

In order to achieve the above object, the invention according to claim 1 comprises a compressor (11) for compressing and discharging a refrigerant, a radiator (12) for radiating the refrigerant discharged from the compressor, and a radiator. A branch portion (14a) that branches the flow of the refrigerant that has flown out, a first decompression portion (15, 21, 23) that decompresses one of the refrigerant that is branched at the branch portion, and a decompression portion that is decompressed by the first decompression portion. A first evaporator (16) for evaporating a refrigerant, a second decompression section (18) for decompressing the other refrigerant branched at the branch section, and a second for evaporating the refrigerant decompressed at the second decompression section. The refrigerant that has flowed out of the second evaporator is sucked from the refrigerant suction port (20c) by the suction action of the injection refrigerant that is injected from the evaporator (19) and the nozzle portion (20a) that depressurizes the refrigerant that has flowed out of the first evaporator. Then, the ejector (20) that mixes the injection refrigerant and the suction refrigerant that is sucked from the refrigerant suction port to raise the pressure in the pressure raising portion (20d) and the enthalpy that increases the enthalpy of the refrigerant that flows into the nozzle portion (20a). And an ascending part (13, 17) ,
The enthalpy rising part exchanges heat between the refrigerant flowing out from the radiator and the refrigerant flowing into the nozzle part, and heats the refrigerant flowing into the nozzle part. The nozzle side internal heat exchanger (13) and the radiator flow out. It has an endothermic side internal heat exchanger (17) that heat-exchanges the refrigerant and the refrigerant sucked into the refrigerant suction port to heat the refrigerant sucked into the refrigerant suction port,
It is an ejector type refrigeration cycle in which the injected refrigerant is a gas phase refrigerant having a superheat degree.

According to this, since the injected refrigerant is a vapor phase refrigerant having a superheat degree, the refrigerant flowing into the nozzle portion (20a) is also a vapor phase refrigerant having a relatively high enthalpy. Therefore, the amount of recovered energy can be increased, and the coefficient of performance (COP) of the ejector refrigeration cycle can be sufficiently improved.

Further, it is desirable to include an enthalpy raising portion (13, 17) that raises the enthalpy of the refrigerant flowing into the nozzle portion (20a) so that the injected refrigerant becomes a vapor phase refrigerant having a superheat degree. According to this, the enthalpy rising portion (13, 17) allows the injected refrigerant to be a vapor-phase refrigerant having a degree of superheat, so that the COP of the ejector refrigeration cycle can be reliably and sufficiently improved. be able to.

It should be noted that the reference numerals in parentheses for each means described in this column and in the claims indicate the correspondence with the specific means described in the embodiments described later.

It is the whole ejector type freezing cycle lineblock diagram of a 1st embodiment. It is a block diagram showing an electric control part of an ejector type freezing cycle of a 1st embodiment. It is a Mollier diagram which shows the state of a refrigerant at the time of operating the ejector type freezing cycle of a 1st embodiment. It is the whole ejector type freezing cycle lineblock diagram of a 2nd embodiment. It is the whole ejector type freezing cycle lineblock diagram of a 3rd embodiment. It is the whole ejector type freezing cycle lineblock diagram of a 4th embodiment. It is an explanatory view for explaining the heat exchange mode of the internal heat exchanger in the ejector type freezing cycle of other embodiments.

(First embodiment)
The first embodiment will be described with reference to FIGS. 1 to 3. In the present embodiment, the ejector refrigeration cycle 10 shown in the overall configuration diagram of FIG. 1 is applied to a vehicle refrigeration cycle device mounted on a refrigeration vehicle.

This refrigeration cycle device for a vehicle has a function of cooling indoor blast air that is blown into the passenger compartment of a refrigerated vehicle, and a function of cooling internal blast air that is blown into a refrigerator disposed on the loading platform of the vehicle. Fulfill. Therefore, the temperature adjustment target fluids of the ejector type refrigeration cycle 10 of the present embodiment are indoor blast air and indoor blast air.

Further, the ejector refrigeration cycle 10 employs an HFC-based refrigerant (specifically, R134a) as a refrigerant, and uses a vapor compression subcritical refrigeration cycle in which the refrigerant pressure on the high pressure side does not exceed the critical pressure of the refrigerant. I am configuring. Further, refrigerating machine oil for lubricating the compressor 11 is mixed in the refrigerant, and a part of the refrigerating machine oil circulates in the cycle together with the refrigerant.

The compressor 11 sucks the refrigerant in the ejector-type refrigeration cycle 10, compresses it until it becomes a high-pressure refrigerant, and discharges it. More specifically, the compressor 11 of the present embodiment is an electric compressor configured to accommodate a fixed displacement type compression mechanism and an electric motor for driving the compression mechanism in one housing.

As such a compression mechanism, various compression mechanisms such as a scroll type compression mechanism and a vane type compression mechanism can be adopted. Further, the electric motor is one whose rotation speed is controlled by a control signal output from a control device 40 described later, and either of an AC motor and a DC motor may be adopted.

The refrigerant inlet side of the radiator 12 is connected to the discharge port of the compressor 11. The radiator 12 exchanges heat between the high-pressure refrigerant discharged from the compressor 11 and the air outside the vehicle cabin (that is, the outside air) blown by the cooling fan 12a to radiate and cool the high-pressure refrigerant. Is. The cooling fan 12a is an electric blower whose rotation speed (that is, the amount of blown air) is controlled by a control voltage output from the control device 40.

The refrigerant outlet of the radiator 12 is connected to the inlet side of the high pressure side refrigerant passage 13 a of the nozzle side internal heat exchanger 13. The nozzle side internal heat exchanger 13 is a heat exchanger for exchanging heat between the high pressure refrigerant flowing through the high pressure side refrigerant passage 13a and the low pressure refrigerant flowing through the low pressure side refrigerant passage 13b.

Such a nozzle-side internal heat exchanger 13 has a double-tube heat exchanger structure in which an inner pipe forming the low-pressure side refrigerant passage 13b is arranged inside an outer pipe forming the high-pressure side refrigerant passage 13a. Things can be adopted.

It should be noted that in FIG. 1, for clarity of explanation, a specific configuration of the nozzle-side internal heat exchanger 13 is not shown, and the high-pressure side refrigerant passage 13a and the low-pressure side of the respective components of the ejector refrigeration cycle 10 and the low-pressure side. The connection relationship of the side refrigerant passage 13b is schematically shown. Then, the refrigerant passages through which the corresponding heat exchange target refrigerant flows are indicated by broken line arrows. This also applies to the suction side internal heat exchanger 17 described later.

The inlet side of the three-way joint 14a is connected to the outlet of the high pressure side refrigerant passage 13a of the nozzle side internal heat exchanger 13. The three-way joint 14 a is a branch portion that branches the flow of the refrigerant flowing out from the radiator 12.

The three-way joint 14a has three inflow/outflow ports, one of the three inflow/outflow ports is a refrigerant inflow port, and the other two are refrigerant outflow ports. The three-way joint 14a may be formed by joining a plurality of pipes, or may be formed by providing a plurality of refrigerant passages in a metal block or a resin block.

The inlet side of the first expansion valve 15 as the first pressure reducing unit is connected to one refrigerant outlet of the three-way joint 14a. The first expansion valve 15 is an electric variable throttle mechanism having a valve body that changes the throttle opening and an electric actuator (specifically, a stepping motor) that displaces the valve body. The operation (namely, throttle opening) of the first expansion valve 15 is controlled by a control signal (specifically, a control pulse) output from the control device 40.

The refrigerant inlet side of the first evaporator 16 is connected to the outlet side of the first expansion valve 15. The first evaporator 16 exchanges heat between the low pressure refrigerant decompressed by the first expansion valve 15 and the indoor blown air that is blown into the vehicle interior from the first blower 16a to evaporate the low pressure refrigerant and endothermic action. It is a heat exchanger for endothermic heat. The first blower 16a is an indoor electric blower whose rotation speed (that is, the amount of blown air) is controlled by a control voltage output from the control device 40.

The inlet side of the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13 is connected to the refrigerant outlet of the first evaporator 16. Further, an outlet side of the low pressure side refrigerant passage 13b is connected to an inlet side of a nozzle portion 20a of an ejector 20 described later.

Therefore, the high-pressure refrigerant flowing through the high-pressure refrigerant passage 13a of the nozzle-side internal heat exchanger 13 is the refrigerant that has flowed out of the radiator 12 and is the refrigerant on the upstream side of the three-way joint 14a. The low-pressure refrigerant flowing through the low-pressure refrigerant passage 13b of the nozzle-side internal heat exchanger 13 is the refrigerant that has flowed out of the first evaporator 16 and that has flowed into the nozzle portion 20a of the ejector 20.

That is, the nozzle-side internal heat exchanger 13 exchanges heat between the refrigerant flowing out from the radiator 12 and the refrigerant flowing into the nozzle portion 20a. Further, the nozzle-side internal heat exchanger 13 is an enthalpy raising portion that raises the enthalpy of the refrigerant flowing into the nozzle portion 20a by heating the refrigerant flowing into the nozzle portion 20a.

The inlet side of the high pressure side refrigerant passage 17a of the suction side internal heat exchanger 17 is connected to the other refrigerant outlet of the three-way joint 14a. The suction side internal heat exchanger 17 is a heat exchanger for exchanging heat between the high pressure refrigerant flowing through the high pressure side refrigerant passage 17a and the low pressure refrigerant flowing through the low pressure side refrigerant passage 17b. The basic structure of the suction side internal heat exchanger 17 is the same as that of the nozzle side internal heat exchanger 13.

An inlet side of a second expansion valve 18 as a second pressure reducing section is connected to an outlet of the high pressure side refrigerant passage 17a of the suction side internal heat exchanger 17. The basic configuration of the second expansion valve 18 is the same as that of the first expansion valve 15. Therefore, the operation of the second expansion valve 18 is controlled by the control signal output from the control device 40.

The refrigerant inlet side of the second evaporator 19 is connected to the outlet side of the second expansion valve 18. The second evaporator 19 exchanges heat between the low-pressure refrigerant decompressed by the second expansion valve 18 and the in-compartment blast air that is circulated and blown into the refrigerator from the second blower 19a to evaporate the low-pressure refrigerant. It is an endothermic heat exchanger that exhibits an endothermic effect. The second blower 19a is an electric blower for the inside of the compartment, the rotation speed (that is, the amount of blown air) is controlled by the control voltage output from the control device 40.

The refrigerant outlet of the second evaporator 19 is connected to the inlet side of the low pressure side refrigerant passage 17b of the suction side internal heat exchanger 17. Further, the refrigerant suction port 20c side of the ejector 20 is connected to the outlet of the low pressure side refrigerant passage 17b.

Therefore, the high pressure refrigerant flowing through the high pressure side refrigerant passage 17a of the suction side internal heat exchanger 17 is the refrigerant that has flowed out of the radiator 12 and is the other refrigerant that is branched at the three-way joint 14a. The low-pressure refrigerant flowing through the low-pressure refrigerant passage 17b of the suction-side internal heat exchanger 17 is the refrigerant that has flowed out of the second evaporator 19 and that is sucked into the refrigerant suction port 20c of the ejector 20.

That is, the suction side internal heat exchanger 17 exchanges heat between the refrigerant flowing out from the radiator 12 and the refrigerant sucked into the refrigerant suction port 20c. Further, the suction side internal heat exchanger 17 is an enthalpy raising portion that balances the cycle so that the refrigerant sucked into the refrigerant suction port 20c is heated to raise the enthalpy of the refrigerant flowing into the nozzle portion 20a.

Next, the ejector 20 functions as a refrigerant decompression device that decompresses the refrigerant flowing out from the first evaporator 16. Further, the ejector 20 functions as a refrigerant circulation device that sucks and circulates the refrigerant from the outside by the suction action of the injected refrigerant injected from the refrigerant injection port of the nozzle portion 20a.

In addition to this, the ejector 20 converts the kinetic energy of the mixed refrigerant of the injection refrigerant injected from the nozzle portion 20a and the suction refrigerant sucked from the refrigerant suction port 20c into pressure energy, and raises the pressure of the mixed refrigerant. It functions as a device.

More specifically, the ejector 20 has a nozzle portion 20a and a body portion 20b. The nozzle portion 20a is formed of a substantially cylindrical metal (stainless steel alloy in the present embodiment) or the like that tapers gradually in the direction of flow of the refrigerant. The nozzle portion 20a is for isentropically decompressing and expanding the refrigerant in the refrigerant passage formed inside.

In the refrigerant passage formed inside the nozzle portion 20a, the throat portion that minimizes the passage cross-sectional area, and the divergent portion where the passage cross-sectional area gradually increases as it goes from the throat portion to the refrigerant injection port that injects the refrigerant Are formed. That is, the nozzle portion 20a of this embodiment is configured as a Laval nozzle.

Further, in this embodiment, as the nozzle portion 20a, a nozzle portion that is set so that the flow velocity of the injected refrigerant injected from the refrigerant injection port during the normal operation of the cycle is equal to or higher than the speed of sound is adopted. Of course, the nozzle portion 20a may be composed of a tapered nozzle.

The body portion 20b is formed of a substantially cylindrical metal (aluminum in this embodiment). The body portion 20b functions as a fixing member that supports and fixes the nozzle portion 20a inside, and forms the outer shell of the ejector 20. More specifically, the nozzle portion 20a is fixed by press fitting so as to be housed inside the one end side in the longitudinal direction of the body portion 20b. The body portion 20b may be made of resin.

In the outer peripheral surface of the body portion 20b, a portion corresponding to the outer peripheral side of the nozzle portion 20a is formed with a refrigerant suction port 20c penetrating the inside and outside thereof and communicating with the refrigerant injection port of the nozzle portion 20a. ing. The refrigerant suction port 20c is a through hole that sucks the refrigerant on the outlet side of the second evaporator 19 into the ejector 20 by the suction action of the injected refrigerant jetted from the nozzle portion 20a.

Inside the body portion 20b, there are provided a suction passage 20e for guiding the suction refrigerant sucked from the refrigerant suction port 20c to the refrigerant injection port side of the nozzle portion 20a, and a pressure increasing portion for mixing the suction refrigerant and the injection refrigerant to raise the pressure. The diffuser portion 20d is formed.

The suction passage 20e is formed in the space between the outer peripheral side around the tapered tip end portion of the nozzle portion 20a and the inner peripheral side of the body portion 20b, and the refrigerant passage area of the suction passage 20e is in the refrigerant flow direction. It is gradually shrinking toward. Thereby, the flow velocity of the suction refrigerant flowing through the suction passage 20e is gradually increased to reduce the energy loss (that is, the mixing loss) when the suction refrigerant and the injection refrigerant are mixed in the diffuser portion 20d.

The diffuser portion 20d is a frustoconical refrigerant passage arranged so as to be continuous with the outlet of the suction passage 20e. In the diffuser portion 20d, the passage cross-sectional area gradually increases toward the refrigerant flow downstream side. The diffuser portion 20d converts the kinetic energy of the mixed refrigerant into pressure energy with such a passage shape.

More specifically, the cross-sectional shape of the inner peripheral wall surface of the body portion 20b forming the diffuser portion 20d of the present embodiment is formed by combining a plurality of curved lines. The degree of expansion of the cross-sectional area of the refrigerant passage of the diffuser portion 20d gradually increases in the refrigerant flow direction and then decreases again, so that the refrigerant can be isentropically pressurized. The suction side of the compressor 11 is connected to the outlet of the diffuser portion 20d.

Next, an outline of the electric control unit of the present embodiment will be described. The control device 40 is composed of a well-known microcomputer including a CPU, a ROM, a RAM and the like and its peripheral circuits. Then, various calculations and processing are performed based on the control program stored in the ROM, and the operations of the various controlled devices 11, 12a, 15, 16a, 18, 19a and the like connected to the output side are controlled.

On the input side of the control device 40, as shown in the block diagram of FIG. 2, an inside air temperature sensor 41, an outside air temperature sensor 42, a solar radiation sensor 43, a discharge temperature sensor 44, a discharge pressure sensor 45, and a first evaporator temperature sensor 46a. , A second evaporator temperature sensor 46b, an inside temperature sensor 47, a nozzle temperature sensor 48a, a nozzle pressure sensor 48b, and the like are connected. Then, the detection signals of these sensor groups are input to the control device 40.

The inside air temperature sensor 41 is an inside air temperature detection unit that detects the vehicle compartment temperature (that is, the inside air temperature) Tr. The outside air temperature sensor 42 is an outside air temperature detection unit that detects the outside temperature of the vehicle cabin (that is, outside air temperature) Tam. The solar radiation sensor 43 is a solar radiation amount detection unit that detects the amount of solar radiation As emitted to the vehicle interior.

The discharge temperature sensor 44 is a discharge temperature detection unit that detects the discharge temperature Td of the refrigerant discharged from the compressor 11. The discharge pressure sensor 45 is a discharge pressure detection unit that detects the discharge pressure Pd of the refrigerant discharged from the compressor 11.

The first evaporator temperature sensor 46a is a first evaporator temperature detection unit that detects the refrigerant evaporation temperature (that is, the first evaporator temperature) Te1 in the first evaporator 16. The second evaporator temperature sensor 46b is a second evaporator temperature detection unit that detects the refrigerant evaporation temperature (that is, the second evaporator temperature) Te2 in the second evaporator 19. The inside temperature sensor 47 is an inside temperature detection unit that detects the temperature inside the freezer.

The nozzle part temperature sensor 48a detects the inlet side temperature Tnoz of the refrigerant flowing out from the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13 and flowing into the nozzle part 20a of the ejector 20, and the inlet side temperature of the nozzle part 20a. It is a detection unit. The nozzle pressure sensor 48b detects the inlet pressure Pnoz of the refrigerant flowing out of the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13 and flowing into the nozzle portion 20a of the ejector 20. It is a detection unit.

Further, as shown in FIG. 2, an operation panel 50 arranged near the instrument panel in the front part of the vehicle compartment is connected to the input side of the control device 40, and various operation switches provided on the operation panel 50 are operated. The operation signal is input to the control device 40.

As various operation switches provided on the operation panel 50, an operation switch of the vehicle refrigeration cycle device for requesting cooling in the compartment and air conditioning in the vehicle compartment, a temperature setting switch for setting a set temperature Tset in the vehicle compartment, An air volume setting switch of the first blower 16a that blows indoor blown air is provided.

Note that the control device 40 of the present embodiment integrally includes control means for controlling the operation of various control target devices connected to the output side of the control device 40. The configuration that controls the operation of the device (that is, hardware and software) constitutes the control means of each controlled device.

For example, in the present embodiment, the configuration that controls the operation of the compressor 11 configures the discharge capacity control unit 40a. Further, the decompression control unit 40b is configured to control the operation of the first expansion valve 15 and the second expansion valve 18.

Next, the operation of the present embodiment having the above configuration will be described. First, when the operation switch of the operation panel is turned on by the user (ON), the control device 40 executes the control program stored in advance.

In this control program, the inside air temperature Tr detected by the inside air temperature sensor 41, the outside air temperature Tam detected by the outside air temperature sensor 42, the solar radiation amount As detected by the solar radiation sensor 43, and the temperature setting switch of the operation panel 50 are set. The target outlet temperature TAO of the air blown into the vehicle compartment is determined based on the set temperature Tset.

Then, the control state of the controlled device is determined based on the determined target outlet temperature TAO, the detection signal detected by the sensor group, and the operation signal from the operation panel 50. Further, the control device 40 causes the electric motor of the compressor 11, the cooling fan 12a, the first expansion valve 15, the first blower 16a, the second expansion valve 18, and the second blower 19a so that the determined control state is obtained. Control the operation of the etc.

As a result, in the ejector-type refrigeration cycle 10, the refrigerant flows as shown by the thick arrow in FIG. 1, and the state of the refrigerant changes as shown by the Mollier diagram in FIG. First, the control device 40 operates the compressor 11, so that the compressor 11 draws in the refrigerant, compresses it, and discharges it. The high-temperature and high-pressure discharge refrigerant (point a3 in FIG. 3) discharged from the compressor 11 flows into the radiator 12.

The refrigerant flowing into the radiator 12 exchanges heat with the blown air (outside air) blown from the cooling fan 12a, radiates heat, and condenses (point a3→point b3 in FIG. 3). The refrigerant flowing out of the radiator 12 flows into the high-pressure side refrigerant passage 13a of the nozzle-side internal heat exchanger 13 and exchanges heat with the low-pressure refrigerant flowing through the low-pressure side refrigerant passage 13b of the nozzle-side internal heat exchanger 13. Decrease enthalpy (b3 point → c3 point in FIG. 3).

The flow of the refrigerant flowing out from the high pressure side refrigerant passage 13a of the nozzle side internal heat exchanger 13 is branched by the three-way joint 14a. One of the refrigerants branched at the three-way joint 14a flows into the first expansion valve 15 and is isenthalpically reduced in pressure (point c3 → point d3 in FIG. 3).

At this time, the control device 40 causes the refrigerant flowing into the nozzle portion 20a calculated based on the inlet side temperature Tnoz detected by the nozzle portion temperature sensor 48a and the inlet side pressure Pnoz detected by the nozzle portion pressure sensor 48b ( The operation of the first expansion valve 15 is controlled so that the superheat degree SHnoz (point f3 in FIG. 3) becomes the reference superheat degree KSHnoz.

The reference superheat degree KSHnoz is determined based on the discharge pressure Pd detected by the discharge pressure sensor 45 and the like by referring to a control map stored in advance in the control device 40. In this control map, the reference superheat degree KSHnoz is determined so that the jet refrigerant (point k3 in FIG. 3) immediately after being jetted from the nozzle portion 20a becomes a vapor phase refrigerant having a superheat degree.

The refrigerant decompressed by the first expansion valve 15 flows into the first evaporator 16 and absorbs heat from the indoor blown air blown by the first blower 16a to be evaporated (point d3→e3 in FIG. 3). ). As a result, the indoor blown air is cooled.

The refrigerant flowing out of the first evaporator 16 flows into the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13 and exchanges heat with the high pressure refrigerant flowing through the high pressure side refrigerant passage 13a to raise the enthalpy. 3 e3 point → f3 point). As a result, the superheat degree SHnoz of the refrigerant (point f3 in FIG. 3) flowing out from the low pressure side refrigerant passage 13b becomes the reference superheat degree KSHnoz.

The refrigerant flowing out from the low pressure side refrigerant passage 13b flows into the nozzle portion 20a of the ejector 20. The refrigerant flowing into the nozzle portion 20a is isentropically decompressed and injected (point f3→point k3 in FIG. 3). Then, due to the suction action of the injected refrigerant, the refrigerant (point j3 in FIG. 3) flowing out from the low pressure side refrigerant passage 17b of the suction side internal heat exchanger 17 is sucked from the refrigerant suction port 20c of the ejector 20.

The refrigerant sucked from the refrigerant suction port 20c is isentropically depressurized to slightly lower the pressure when flowing through the suction passage 20e formed inside the ejector 20 (j3 point→m3 point in FIG. 3). ). The injection refrigerant injected from the nozzle portion 20a and the suction refrigerant sucked from the refrigerant suction port 20c flow into the diffuser portion 20d of the ejector 20 (k3 point→n3 point, m3 point→n3 point in FIG. 3).

In the diffuser portion 20d, the velocity energy of the refrigerant is converted into pressure energy due to the expansion of the refrigerant passage area. As a result, the pressure of the mixed refrigerant of the injected refrigerant and the sucked refrigerant rises (point n3 → point o3 in FIG. 3). The refrigerant flowing out from the diffuser portion 20d is sucked into the compressor 11 and compressed again (point o3→point a3 in FIG. 3).

On the other hand, the other refrigerant branched by the three-way joint 14a flows into the high pressure side refrigerant passage 17a of the suction side internal heat exchanger 17 and flows into the low pressure side refrigerant passage 17b of the suction side internal heat exchanger 17 at a low pressure. It exchanges heat with the refrigerant to lower the enthalpy (point c3 → point g3 in FIG. 3).

The refrigerant flowing out from the high pressure side refrigerant passage 17a of the suction side internal heat exchanger 17 flows into the second expansion valve 18 and is isenthalpically reduced in pressure (g3 point→h3 point in FIG. 3). At this time, the control device 40 controls the operation of the second expansion valve 18 so that the refrigerant evaporation temperature in the second evaporator 19 becomes the reference temperature for the refrigerator (5° C. in the present embodiment).

Therefore, the pressure of the refrigerant decompressed by the second expansion valve 18 becomes lower than the pressure of the refrigerant decompressed by the first expansion valve 15. In FIG. 3, the pressure at the h3 point is higher than the pressure at the d3 point. More specifically, in the control device 40, based on the discharge pressure Pd detected by the discharge pressure sensor 45 and the like, a control map stored in advance in the control device 40 is referred to, and the throttle of the second expansion valve 18 is throttled. The opening is determined.

The refrigerant decompressed by the second expansion valve 18 flows into the second evaporator 19, and absorbs heat from the inside-air blowing air circulated and blown by the second blower 19a to evaporate (point h3 in FIG. 3 → i 3 points). Thereby, the blast air for the inside of the refrigerator is cooled.

The refrigerant flowing out from the second evaporator 19 flows into the low pressure side refrigerant passage 17b of the suction side internal heat exchanger 17, exchanges heat with the high pressure refrigerant flowing through the high pressure side refrigerant passage 17a, and raises the enthalpy. 3 i3 point→j3 point). As a result, the refrigerant flowing out from the low pressure side refrigerant passage 17b becomes a superheated vapor phase refrigerant. The refrigerant flowing out from the low pressure side refrigerant passage 17b is sucked from the refrigerant suction port 20c of the ejector 20 as described above.

The ejector-type refrigeration cycle 10 of the present embodiment can operate as described above to cool the indoor blast air that is blown into the vehicle compartment and the indoor blast air that is circulated and blown into the refrigerator. At this time, since the refrigerant evaporation pressure (refrigerant evaporation temperature) of the first evaporator 16 and the refrigerant evaporation pressure (refrigerant evaporation temperature) of the second evaporator 19 can be different values, different temperatures can be set in the vehicle compartment and the refrigerator. Can be cooled in strips.

Further, in the ejector type refrigeration cycle 10, since the refrigerant (point o3 in FIG. 3) whose pressure is increased by the diffuser portion 20d of the ejector 20 is sucked into the compressor 11, the power consumption of the compressor 11 is reduced and the cycle of the cycle is reduced. The coefficient of performance (COP) can be improved.

In addition to this, in the ejector-type refrigeration cycle 10 of the present embodiment, the injection refrigerant (point k3 in FIG. 3) injected from the nozzle portion 20a of the ejector 20 is a gas-phase refrigerant having a superheat degree, The refrigerant (point f3 in FIG. 3) flowing into the portion 20a also becomes a vapor phase refrigerant having a relatively high enthalpy.

Therefore, the amount of energy recovered by the ejector 20 can be increased more than in the cycle in which the refrigerant flowing into the nozzle portion 20a of the ejector 20 becomes a gas-liquid two-phase refrigerant. As a result, according to the ejector refrigeration cycle 10 of this embodiment, the COP of the cycle can be sufficiently improved.

Further, in the ejector refrigeration cycle 10 of the present embodiment, the nozzle side internal heat exchange, which is an enthalpy increasing portion that increases the enthalpy of the refrigerant flowing into the nozzle portion 20a, so that the injected refrigerant becomes a vapor phase refrigerant having a superheat degree. The container 13 and the suction side internal heat exchanger 17 are provided. According to this, the COP of the ejector-type refrigeration cycle 10 can be reliably and sufficiently improved.

More specifically, a nozzle-side internal heat exchanger 13 for exchanging heat between the refrigerant flowing out of the radiator 12 and the refrigerant flowing into the nozzle portion 20a is provided as the enthalpy rising portion. According to this, the refrigerant flowing into the nozzle portion 20a can be directly heated by the high-pressure refrigerant, and the injected refrigerant can be a vapor-phase refrigerant having a superheat degree.

Furthermore, in the nozzle-side internal heat exchanger 13, the enthalpy of the refrigerant flowing into the first evaporator 16 can be reduced. Therefore, the enthalpy difference obtained by subtracting the enthalpy of the refrigerant on the inlet side of the first evaporator 16 from the enthalpy of the refrigerant on the outlet side of the first evaporator 16 can be expanded to increase the refrigerating capacity exhibited in the first evaporator 16. it can.

Further, as an enthalpy rising portion, a suction side internal heat exchanger 17 for heating the refrigerant sucked into the refrigerant suction port 20c by exchanging heat between the refrigerant flowing out from the radiator 12 and the refrigerant sucked into the refrigerant suction port 20c. Is equipped with. According to this, it is easy to balance the cycle so that the enthalpy of the refrigerant flowing into the nozzle portion 20a increases.

Furthermore, the suction side internal heat exchanger 17 can reduce the enthalpy of the refrigerant flowing into the second evaporator 19. Therefore, the enthalpy difference obtained by subtracting the enthalpy of the refrigerant on the inlet side of the second evaporator 19 from the enthalpy of the refrigerant on the outlet side of the second evaporator 19 can be expanded to increase the refrigerating capacity exhibited in the second evaporator 19. it can.

As a result, the COP of the ejector type refrigeration cycle 10 can be reliably and sufficiently improved.

Further, in the ejector-type refrigeration cycle 10 of the present embodiment, the high-pressure refrigerant flowing through the high-pressure side refrigerant passage 13a of the nozzle-side internal heat exchanger 13 is the refrigerant flowing out from the radiator 12 and is located on the upstream side of the three-way joint 14a. It is a refrigerant. Further, the high pressure refrigerant flowing through the high pressure side refrigerant passage 17a of the suction side internal heat exchanger 17 is the other refrigerant branched at the three-way joint 14a.

According to this, the temperature of the high pressure refrigerant flowing through the high pressure side refrigerant passage 13a of the nozzle side internal heat exchanger 13 is higher than the temperature of the high pressure refrigerant flowing through the high pressure side refrigerant passage 17a of the suction side internal heat exchanger 17. Become. Therefore, in the nozzle-side internal heat exchanger 13, the refrigerant flowing into the nozzle portion 20a can be efficiently heated and the injected refrigerant can be a vapor-phase refrigerant having a superheat degree.

Further, in the ejector-type refrigeration cycle 10 of the present embodiment, the decompression control unit 40b of the control device 40 sets the first expansion valve 15 so that the superheat degree SHnoz of the refrigerant flowing into the nozzle portion 20a becomes the reference superheat degree KSHnoz. It controls the operation. Therefore, in the ejector type refrigeration cycle 10, the injection refrigerant injected from the nozzle portion 20a can be surely made into a vapor phase refrigerant having a superheat degree, and the COP of the cycle can be more surely improved.

(Second embodiment)
In the present embodiment, as shown in the overall configuration diagram of FIG. 4, an ejector refrigeration cycle 10a in which a high-stage ejector 21, a gas-liquid separator 22 and a fixed throttle 23 are added to the first embodiment will be described. To do. In FIG. 4, the same or equivalent parts as those in the first embodiment are designated by the same reference numerals. This also applies to the following drawings.

More specifically, the basic structure of the high-stage ejector 21 is the same as that of the ejector 20. Therefore, the high-stage ejector 21 has the high-stage nozzle portion 21a and the high-stage body portion 21b. Further, a high-stage side refrigerant suction port 21c is formed in the high-stage side body portion 21b. Inside the high-stage side body portion 21b, a high-stage side diffuser portion 21d which is a high-stage side boosting portion and a high-stage side suction passage 21e are formed.

The high-stage side nozzle portion 21a is configured to further depressurize and inject the refrigerant that is one of the refrigerant branched at the three-way joint 14a and that has flowed out from the first expansion valve 15. The inlet side of the gas-liquid separator 22 is connected to the outlet side of the high-stage side diffuser portion 21d.

The gas-liquid separator 22 is a gas-liquid separating unit that separates the gas-liquid of the refrigerant flowing out from the high-stage diffuser section 21d. The gas-phase refrigerant outlet of the gas-liquid separator 22 is connected to the inlet side of the low-pressure side refrigerant passage 13b of the nozzle-side internal heat exchanger 13. The liquid-phase refrigerant outlet of the gas-liquid separator 22 is connected to the refrigerant inlet side of the first evaporator 16 via the fixed throttle 23. The high-stage side refrigerant suction port 21c side of the high-stage side ejector 21 is connected to the refrigerant outlet of the first evaporator 16.

The fixed throttle 23 reduces the pressure of the liquid-phase refrigerant flowing out from the liquid-phase refrigerant outlet. As such a fixed throttle 23, an orifice, a capillary tube, a nozzle or the like can be adopted. That is, the high-stage ejector 21 and the fixed throttle 23 of the present embodiment together with the first expansion valve 15 constitute a first pressure reducing section. Other configurations of the ejector-type refrigeration cycle 10a are the same as those in the first embodiment.

Therefore, when the ejector type refrigeration cycle 10a of the present embodiment is operated, the refrigerant decompressed by the first expansion valve 15 flows into the high stage side nozzle portion 21a of the high stage side ejector 21. The refrigerant flowing into the high-stage side nozzle portion 21a is isentropically decompressed and injected. Then, due to the suction action of the high-stage side injected refrigerant, the refrigerant flowing out of the first evaporator 16 is sucked from the high-stage side refrigerant suction port 21c of the high-stage ejector 21.

The mixed refrigerant of the high-stage side injection refrigerant and the high-stage side suction refrigerant sucked from the high-stage side refrigerant suction port 21c is pressurized by the high-stage side diffuser portion 21d. The refrigerant flowing out from the high-stage diffuser portion 21d flows into the gas-liquid separator 22 and is separated into gas and liquid.

The liquid-phase refrigerant separated by the gas-liquid separator 22 is decompressed by the fixed throttle 23 and flows into the first evaporator 16. The refrigerant flowing into the first evaporator 16 absorbs heat from the blown air blown by the first blower 16a and evaporates, as in the first embodiment. As a result, the indoor blown air is cooled. On the other hand, the gas-phase refrigerant separated by the gas-liquid separator 22 flows into the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13.

Other operations are the same as those in the first embodiment. Therefore, when the ejector type refrigeration cycle 10a of the present embodiment is operated, the same effect as that of the first embodiment can be obtained. That is, the amount of recovered energy recovered by the ejector 20 can be increased more than in the cycle in which the refrigerant flowing into the nozzle portion 20a of the ejector 20 becomes a gas-liquid two-phase refrigerant, and the COP of the cycle can be sufficiently improved. ..

Further, the ejector-type refrigeration cycle 10a of the present embodiment includes the high-stage ejector 21, so that the pressure of the refrigerant flowing into the low-pressure side refrigerant passage 13b of the nozzle-side internal heat exchanger 13 is set in the first evaporator 16. It can be raised above the refrigerant evaporation pressure. Therefore, the power consumption of the compressor 11 can be reduced to further improve the cycle COP.

Further, in the ejector-type refrigeration cycle 10a of the present embodiment, the saturated vapor phase refrigerant separated by the vapor-liquid separator 22 flows into the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13. Therefore, the superheat degree SHnoz of the refrigerant flowing into the nozzle portion 20a of the ejector 20 can be brought closer to the reference superheat degree KSHnoz more than when the gas-liquid two-phase refrigerant flows into the low pressure side refrigerant passage 13b.

(Third Embodiment)
In this embodiment, as shown in the overall configuration diagram of FIG. 5, an ejector refrigeration system in which a high-stage three-way joint 14b, a third evaporator 24, and a high-stage ejector 21 are added to the first embodiment. The cycle 10b will be described.

More specifically, the basic configuration of the high-stage side three-way joint 14b is the same as that of the three-way joint 14a. The high-stage side three-way joint 14b is a high-stage side branch portion that branches the flow of the refrigerant flowing out from the first expansion valve 15. The inlet side of the high-stage side nozzle portion 21a of the high-stage side ejector 21 is connected to one refrigerant outlet of the high-stage side three-way joint 14b. The refrigerant inlet side of the third evaporator 24 is connected to the outlet side of the high-stage diffuser portion 21d of the high-stage ejector 21.

The basic configuration of the third evaporator 24 is similar to that of the first evaporator 16. The third evaporator 24 exchanges heat between the refrigerant flowing out of the high-stage side diffuser portion 21d and the indoor blown air that is blown into the vehicle interior from the third blower 24a, and evaporates the low-pressure refrigerant to exert an endothermic effect. It is a heat exchanger for heat absorption. The refrigerant outlet of the third evaporator 24 is connected to the inlet side of the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13.

The refrigerant inlet side of the first evaporator 16 is connected to the other refrigerant outlet of the high-stage side three-way joint 14b via the fixed throttle 23. The high- stage side refrigerant suction port 21c side of the high- stage side ejector 21 is connected to the refrigerant outlet of the first evaporator 16. That is, the fixed throttle 23 of the present embodiment constitutes the first decompression unit together with the first expansion valve 15. Other configurations of the ejector-type refrigeration cycle 10b are the same as those of the ejector-type refrigeration cycle 10 of the first embodiment.

Therefore, when the ejector-type refrigeration cycle 10 of the present embodiment is operated, the flow of the refrigerant decompressed by the first expansion valve 15 is branched by the high-stage side three-way joint 14b. One refrigerant branched at the high-stage side three-way joint 14b flows into the high-stage nozzle portion 21a of the high-stage ejector 21. As a result, similarly to the second embodiment, the refrigerant flowing out from the first evaporator 16 is sucked from the high-stage side refrigerant suction port 21c of the high-stage side ejector 21.

The mixed refrigerant of the high-stage side injection refrigerant and the high-stage side suction refrigerant sucked from the high-stage side refrigerant suction port 21c is pressurized by the high-stage side diffuser portion 21d. The refrigerant flowing out from the high-stage side diffuser portion 21d flows into the third evaporator 24.

The refrigerant flowing into the third evaporator 24 absorbs heat from the indoor blown air blown from the third blower 24a and evaporates. As a result, the indoor blown air is cooled. The refrigerant flowing out from the third evaporator 24 flows into the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13.

One of the refrigerants branched at the high-stage side three-way joint 14b is depressurized when flowing through the fixed throttle 23 and flows into the first evaporator 16. The refrigerant flowing into the first evaporator 16 absorbs heat from the blown air blown by the first blower 16a and evaporates, as in the first embodiment. As a result, the indoor blown air is cooled.

Other operations are the same as those in the first embodiment. Therefore, when the ejector type refrigeration cycle 10b of this embodiment is operated, the same effect as that of the first embodiment can be obtained. That is, the amount of recovered energy recovered by the ejector 20 can be increased more than in the cycle in which the refrigerant flowing into the nozzle portion 20a of the ejector 20 becomes a gas-liquid two-phase refrigerant, and the COP of the cycle can be sufficiently improved. .

Further, since the ejector-type refrigeration cycle 10b of the present embodiment includes the high-stage ejector 21, the pressure of the refrigerant flowing into the low-pressure side refrigerant passage 13b of the nozzle-side internal heat exchanger 13 is set in the first evaporator 16. It can be raised above the refrigerant evaporation pressure. Therefore, the COP of the cycle can be further improved.

Further, in the ejector type refrigeration cycle 10b of the present embodiment, the gas-liquid two-phase refrigerant having a relatively high degree of dryness evaporated in the third evaporator 24 is introduced into the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13 or Introduce a gas phase refrigerant. Therefore, similarly to the second embodiment, the superheat degree SHnoz of the refrigerant flowing into the nozzle portion 20a of the ejector 20 can easily approach the reference superheat degree KSHnoz.

Further, in the ejector-type refrigeration cycle 10b of the present embodiment, the refrigerant decompressed by the fixed throttle 23 flows into the first evaporator 16, and the refrigerant is pressurized by the high-stage diffuser portion 21d of the high-stage ejector 21. To the third evaporator 24.

According to this, since the refrigerant evaporation pressure (refrigerant evaporation temperature) in the first evaporator 16 becomes lower than the refrigerant evaporation pressure (refrigerant evaporation temperature) in the third evaporator 24, the first evaporator 16 and the third evaporation 16 The air blower for indoor use can be cooled by the device 24 in different temperature zones.

(Fourth Embodiment)
In this embodiment, an example in which the ejector-type refrigeration cycle 10c shown in the overall configuration diagram of FIG. 6 is applied to a vehicle air conditioner 1 will be described. The ejector-type refrigeration cycle 10c has a function of cooling or heating indoor blast air (hereinafter, simply referred to as blast air in the present embodiment) that is blown into a vehicle compartment that is an air conditioning target space in a vehicle air conditioner. Fulfill. Therefore, the fluid whose temperature is adjusted in the ejector-type refrigeration cycle 10c is blown air.

The ejector-type refrigeration cycle 10c can switch the refrigerant circuit in order to air-condition the vehicle interior. Specifically, the ejector-type refrigeration cycle 10c has a cooling mode refrigerant circuit for cooling the blown air to cool the vehicle interior and a heating mode for heating the blown air to heat the vehicle interior. The refrigerant circuit can be switched. In FIG. 6, the flow of the refrigerant in the refrigerant circuit in the cooling mode is indicated by a white arrow, and the flow of the refrigerant in the refrigerant circuit in the heating mode is indicated by a black arrow.

The radiator 12 of the present embodiment is arranged in an air conditioning case 31 of an indoor air conditioning unit 30 of the vehicle air conditioning device 1 described later. Further, the radiator 12 of the present embodiment exchanges heat between the high pressure refrigerant discharged from the compressor 11 and the blown air blown from the first blower 16a. In the ejector type refrigeration cycle 10c, the cooling fan 12a is eliminated.

Therefore, the radiator 12 of the present embodiment not only functions as a heat radiating heat exchanger that radiates the high pressure refrigerant, but also functions as a heating heat exchanger that heats the blown air.

The inlet of the three-way joint 14a is connected to the outlet of the radiator 12. Further, the ejector-type refrigeration cycle 10c of the present embodiment includes the second to fourth three-way joints 14c to 14e. The basic configuration of the second to fourth three-way joints 14c to 14e is the same as that of the three-way joint 14a. Therefore, in the following description, the three-way joint 14a is referred to as a first three-way joint 14a for the sake of clarity.

The inlet side of the high pressure side refrigerant passage 13a of the nozzle side internal heat exchanger 13 is connected to one refrigerant outlet of the first three-way joint 14a. One outlet side of the second three-way joint 14c is connected to the outlet of the high pressure side refrigerant passage 13a of the nozzle side internal heat exchanger 13 via the first expansion valve 15.

The inlet side of the high-pressure side refrigerant passage 17a of the suction side internal heat exchanger 17 is connected to the other refrigerant outlet of the first three-way joint 14a. The refrigerant inlet side of the second evaporator 19 is connected to the outlet of the high pressure side refrigerant passage 17 a of the suction side internal heat exchanger 17 via the second expansion valve 18.

Furthermore, the ejector refrigeration cycle 10c includes a third expansion valve 25 in addition to the first expansion valve 15 and the second expansion valve 18. The basic configuration of the third expansion valve 25 is similar to that of the first expansion valve 15 and the second expansion valve 18.

The first to third expansion valves 15, 18, and 25 of the present embodiment have a fully open function that functions as a simple refrigerant passage with almost no flow rate adjusting action and refrigerant depressurizing action by fully opening the valve opening degree, and It has a fully closed function of closing the refrigerant passage by fully closing the valve opening.

The fully open function and the fully closed function allow the first to third expansion valves 15, 18, 25 to switch between the refrigerant circuit in the cooling mode and the refrigerant circuit in the heating mode. Therefore, the first to third expansion valves 15, 18, 25 also have a function as a refrigerant circuit switching device.

The second evaporator 19 of the present embodiment is arranged in the front side of the vehicle hood, that is, outside the vehicle compartment. Therefore, the second evaporator 19 of this embodiment functions as an outdoor heat exchanger that exchanges heat between the refrigerant flowing out from the second expansion valve 18 and the outside air blown by the second blower 19a. Further, the second evaporator 19 functions as a radiator that dissipates the high pressure refrigerant in the cooling mode, and functions as an evaporator that evaporates the low pressure refrigerant in the heating mode.

The inlet side of the third three-way joint 14d is connected to the refrigerant outlet of the second evaporator 19 which is an outdoor heat exchanger. The other inlet of the second three-way joint 14c is connected to one outlet of the third three-way joint 14d via the third expansion valve 25. The refrigerant inlet side of the first evaporator 16 is connected to the outlet of the second three-way joint 14c.

The first evaporator 16 of the present embodiment is arranged in the air conditioning case 31 of the indoor air conditioning unit 30. The inlet side of the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13 is connected to the refrigerant outlet of the first evaporator 16. The inlet side of the three-way valve 26 is connected to the outlet of the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13.

The three-way valve 26 bypasses the ejector 20 and the refrigerant circuit that guides the refrigerant flowing out from the low-pressure side refrigerant passage 13b of the nozzle-side internal heat exchanger 13 to the inlet side of the nozzle portion 20a of the ejector 20, and the fourth three-way joint. The refrigerant circuit that leads to the suction side of the compressor 11 via 14e is switched.

Therefore, the three-way valve 26 is a refrigerant circuit switching device together with the first to third expansion valves 15, 18, 25. The operation of the three-way valve 26 is controlled by a control signal output from the control device 40.

The inlet side of the low pressure side refrigerant passage 17b of the suction side internal heat exchanger 17 is connected to the other outlet of the third three-way joint 14d. The refrigerant suction port 20c side of the ejector 20 is connected to the outlet of the low pressure side refrigerant passage 17b of the suction side internal heat exchanger 17. Other configurations of the ejector-type refrigeration cycle 10c are similar to those of the ejector-type refrigeration cycle 10 of the first embodiment.

Next, the indoor air conditioning unit 30 will be described. The indoor air conditioning unit 30 is arranged inside the instrument panel (instrument panel) at the frontmost part of the vehicle compartment. The indoor air conditioning unit 30 has a function of switching a ventilation path for appropriately blowing the blown air whose temperature is adjusted by the ejector type refrigeration cycle 10c into the vehicle interior.

The indoor air conditioning unit 30 accommodates the first blower 16a, the first evaporator 16, the radiator 12 and the like in an air passage formed in an air conditioning case 31 forming an outer shell thereof. The air conditioning case 31 forms an air passage for blown air that is blown into the vehicle interior. An inside/outside air switching device 33 that switches and introduces inside air (air inside the vehicle interior) and outside air (air outside the vehicle interior) into the air conditioning case 31 is arranged on the most upstream side of the air flow of the air conditioning case 31.

The inside/outside air switching device 33 continuously adjusts the opening areas of the inside air introducing port for introducing the inside air into the air conditioning case 31 and the outside air introducing port for introducing the outside air by the inside/outside air switching door to introduce the introduced air amount of the inside air and the outside air. The introduction rate is changed with the introduction air volume of. The inside/outside air switching door is driven by an electric actuator for the inside/outside air switching door. The operation of this electric actuator is controlled by a control signal output from the control device 40.

A first blower 16a is arranged on the downstream side of the blown air flow of the inside/outside air switching device 33. Further, the first evaporator 16 and the radiator 12 are arranged in this order with respect to the blast air flow on the downstream side of the blast air flow of the first blower 16a. That is, the first evaporator 16 is arranged on the upstream side of the blower air flow with respect to the radiator 12. Therefore, in the radiator 12, the high-pressure refrigerant and the blown air after passing through the first evaporator 16 are heat-exchanged.

In the air-conditioning case 31, a bypass passage 35 is provided in which the blast air that has passed through the first evaporator 16 flows around the radiator 12. Further, an air mix door 34 is arranged in the air conditioning case 31 on the downstream side of the blast air flow of the first evaporator 16 and on the upstream side of the blast air flow of the radiator 12.

The air mix door 34 adjusts the air volume ratio between the air volume of the air blown through the radiator 12 side and the air volume of the air blown through the bypass passage 35 in the air blown after passing through the first evaporator 16. It is an adjusting unit. The air mix door 34 is driven by an electric actuator for the air mix door. The operation of this electric actuator is controlled by a control signal output from the control device 40.

On the downstream side of the blast air flow of the radiator 12 and the bypass passage 35, the blast air that has been heated by exchanging heat with the refrigerant in the radiator 12 and the blast air that has not been heated through the bypass passage 35 join together. A space is formed. Further, an opening hole for blowing out the blast air mixed in the mixing space (that is, the conditioned air) into the vehicle compartment, which is the air conditioning target space, is arranged at the downstream side of the blast air flow of the air conditioning case 31.

Therefore, the air mix door 34 can adjust the temperature of the conditioned air mixed in the mixing space by adjusting the air flow rate of the air flow passing through the radiator 12 and the air flow passing through the bypass passage 35. .. This makes it possible to adjust the temperature of the blown air (air-conditioned air) blown from each outlet into the passenger compartment.

Next, the operation of the present embodiment having the above configuration will be described. As described above, the vehicle air conditioner 1 of the present embodiment can cool and heat the vehicle interior. Further, in the ejector-type refrigeration cycle 10c, the refrigerant circuit in the cooling mode and the refrigerant circuit in the heating mode can be switched.

Switching of each operation mode of the ejector refrigeration cycle 10c is performed by the control device 40 executing a control program stored in advance. In the control program of the present embodiment, the target outlet temperature TAO of the air blown into the passenger compartment is switched to the cooling mode when it is lower than the predetermined cooling reference temperature, and switched to the heating mode when it is higher than the predetermined heating reference temperature. The operation in each operation mode will be described below.

(A) Cooling Mode In the cooling mode, the control device 40 sets the first expansion valve 15 to a fully closed state, the second expansion valve 18 to a fully open state, and the third expansion valve 25 to a throttled state that exhibits a pressure reducing action. .. At this time, the control device 40 adjusts the throttle opening degree of the third expansion valve 25 so that the suction refrigerant sucked into the compressor 11 approaches a predetermined reference dryness (5° C. in this embodiment). ..

Further, the control device 40 displaces the air mix door 34 so that the ventilation passage on the radiator 12 side is fully closed and the bypass passage 35 side is fully opened. Further, the control device 40 controls the operation of the three-way valve 26 so that the refrigerant flowing out from the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13 bypasses the ejector 20 and is guided to the suction side of the compressor 11. ..

As a result, in the ejector-type refrigeration cycle 10c in the cooling mode, as shown by the white arrow in FIG. 6 , the compressor 11 (→radiator 12→high pressure side refrigerant passage 17a of the suction side internal heat exchanger 17→second expansion Valve 18)→second evaporator 19→third expansion valve 25→first evaporator 16 (→refrigerant passage 13b on the low pressure side of the nozzle side internal heat exchanger 13)→compressor 11 The refrigeration cycle of is constructed.

In the cooling mode cycle configuration, since the air mix door 34 is displaced so that the ventilation passage on the radiator 12 side is fully closed, the radiator 12 hardly radiates heat. Therefore, in the ejector-type refrigeration cycle 10c in the cooling mode, the second evaporator 19 which is an outdoor heat exchanger functions as a radiator that radiates the refrigerant, and the first evaporator 16 functions as an evaporator that evaporates the refrigerant.

Then, the heat absorbed from the blown air when the refrigerant is evaporated in the first evaporator 16 can be radiated to the outside air in the second evaporator 19 . Therefore, in the ejector-type refrigeration cycle 10c in the cooling mode, the air in the vehicle interior can be cooled by blowing the blown air cooled by the first evaporator 16 into the vehicle interior.

Further, in the ejector type refrigeration cycle 10c of the present embodiment, the high pressure side refrigerant passage 13a of the nozzle side internal heat exchanger 13 is connected to one outlet side of the three-way joint 14a. Therefore, in the cooling mode, the high pressure refrigerant does not flow into the high pressure side refrigerant passage 13a of the nozzle side internal heat exchanger 13, and unnecessary heat exchange is performed in the nozzle side internal heat exchanger 13. Never.

(B) Heating Mode In the heating mode, the control device 40 sets the first expansion valve 15 in the throttled state, the second expansion valve 18 in the throttled state, and the third expansion valve 25 in the fully closed state. At this time, the control device 40 adjusts the throttle openings of the first expansion valve 15 and the second expansion valve 18, as in the first embodiment.

Further, the control device 40 displaces the air mix door 34 so that the bypass passage 35 side is fully closed and the ventilation passage on the radiator 12 side is fully opened. Further, the control device 40 controls the operation of the three-way valve so that the refrigerant flowing out from the low pressure side refrigerant passage 13b of the nozzle side internal heat exchanger 13 is guided to the inlet side of the nozzle portion 20a of the ejector 20.

Thereby, in the ejector type refrigeration cycle 10c in the heating mode, as shown by a black arrow in FIG. 6 , the compressor 11→the radiator 12→the high pressure side refrigerant passage 13a of the nozzle side internal heat exchanger 13→the first expansion valve. Refrigerant circulates in the order of 15→first evaporator 16→low pressure side refrigerant passage 13b of nozzle side internal heat exchanger 13→ejector 20→compressor 11, and radiator 12→high pressure side of suction side internal heat exchanger 17 An ejector type refrigeration cycle in which the refrigerant circulates in the order of the refrigerant passage 17a→the second expansion valve 18→the second evaporator 19→the low pressure side refrigerant passage 17b of the suction side internal heat exchanger 17→the refrigerant suction port 20c of the ejector 20 is configured. It

In the cycle configuration of the heating mode, the air mix door 34 is displaced so that the ventilation passage on the radiator 12 side is fully opened. Therefore, in the ejector-type refrigeration cycle 10c in the heating mode, the radiator 12 functions as a radiator that radiates the refrigerant, and the first evaporator 16 and the second evaporator 19 function as an evaporator that evaporates the refrigerant.

Then, the heat absorbed from the blown air when the refrigerant is evaporated in the first evaporator 16 and the heat absorbed from the outside air when the refrigerant is evaporated in the second evaporator 19 are blown to the blower air by the radiator 12. Can be radiated. Therefore, in the ejector-type refrigeration cycle 10c in the heating mode, the blast air cooled and dehumidified by the first evaporator 16 is reheated by the radiator 12 and blown out into the vehicle interior to perform dehumidification and heating in the vehicle interior. It can be carried out.

Further, in the ejector type refrigeration cycle 10c in the heating mode, the enthalpy of the refrigerant flowing into the nozzle portion 20a in the nozzle side internal heat exchanger 13 is controlled by controlling the first expansion valve 15 and the like in the same manner as in the first embodiment. By rising, the injection refrigerant can be changed to a vapor phase refrigerant having a superheat degree.

Therefore, the amount of recovered energy recovered by the ejector 20 can be increased more than in the cycle in which the refrigerant flowing into the nozzle portion 20a of the ejector 20 becomes a gas-liquid two-phase refrigerant, and the COP of the cycle can be sufficiently improved. ..

(Other embodiments)
The present invention is not limited to the above-described embodiments, but can be variously modified as follows without departing from the spirit of the present invention.

(1) In the above-described embodiment, an example in which the ejector refrigeration cycle 10 to 10c including the ejector 20 is applied to a refrigeration cycle device for a vehicle has been described, but the application target of the ejector refrigeration cycle 10 to 10c is limited to this. Not done.

For example, it may be applied to a stationary refrigerating machine or the like. When applied to a stationary refrigerating apparatus, the first evaporator 16 is a refrigerating unit that blows food, drinking water, etc. at a low temperature (specifically, 0°C to 10°C) into a refrigerating room. Blower air for the freezer compartment, which cools the room blast air and is blown to the freezer compartment where the second evaporator 19 freezes and preserves foods and the like at an extremely low temperature (specifically, -20°C to -10°C) May be cooled.

Further, in the third embodiment, the cooling target space of the first evaporator 16 and the third evaporator 24 is not described in detail, but the same cooling target space is used in the first evaporator 16 and the third evaporator 24. The blown air blown to the air may be cooled, or the blown air blown to different cooling target spaces may be cooled.

Furthermore, when cooling the blown air blown to the same cooling target space by the first evaporator 16 and the third evaporator 24, the first evaporator 16 and the third evaporator 24 are integrally formed. At the same time, the blast air cooled by either one of the evaporators may be further cooled by the other evaporator by arranging in series with respect to the blast air flow.

(2) In the above-described embodiment, the example in which the nozzle-side internal heat exchanger 13 and the suction-side internal heat exchanger 17 are adopted as the enthalpy rising portion has been described, but the enthalpy rising portion is not limited to this. As long as the enthalpy of the refrigerant flowing into the nozzle portion 20a of the ejector 20 can be raised, a heater or the like using an external heat source may be adopted as the enthalpy raising portion.

More specifically, an electric heater whose heating capacity can be adjusted by a control voltage output from the control device 40 may be used as the heater. Further, in the ejector refrigeration cycle 10 to 10c applied to the vehicle, a heating device that heats the refrigerant by using waste heat of another vehicle-mounted device (for example, an internal combustion engine, an inverter, etc.) as a heat source may be adopted.

Further, in the above-described embodiment, an example in which the internal heat exchangers of both the nozzle-side internal heat exchanger 13 and the suction-side internal heat exchanger 17 are adopted as the enthalpy rising portion has been described, but either one of the internal heat exchangers is used. A exchanger may be adopted. For example, the suction side internal heat exchanger 17 may be omitted.

Furthermore, the refrigerant to be heat-exchanged in the nozzle-side internal heat exchanger 13 and the suction-side internal heat exchanger 17 is not limited to the combination disclosed in the above embodiment. That is, as long as the enthalpy of the refrigerant flowing into the nozzle portion 20a can be increased, the low pressure in the nozzle-side internal heat exchanger 13 and the suction-side internal heat exchanger 17 different from the combination disclosed in each of the above-described embodiments. You may heat-exchange a refrigerant and a high pressure refrigerant.

Specifically, as shown in FIG. 7, a high pressure refrigerant in a region X (a high pressure refrigerant flowing through a refrigerant flow path from a refrigerant outlet side of the radiator 12 to an inlet side of the three-way joint 14a) and a high pressure refrigerant in a region Y (three-way joint). 14a, the high-pressure refrigerant flowing in the refrigerant flow path from one refrigerant outlet to the inlet side of the first expansion valve 15), and the high-pressure refrigerant in the region Z (the other refrigerant outlet of the three-way joint 14a to the second expansion valve 17). Any one of the high-pressure refrigerant flowing through the refrigerant flow path to the inlet side of the refrigerant, the low-pressure refrigerant in the area α (low-pressure refrigerant flowing into the nozzle portion 20a) and the low-pressure refrigerant in area β (suctioned to the refrigerant suction port 20c). Any one of the low-pressure refrigerant) may be heat-exchanged.

(3) In the above-described embodiment, an example in which the control device 40 controls the operation of the first expansion valve 15 so that the injected refrigerant becomes a vapor-phase refrigerant having a superheat degree has been described. The control mode for using the vapor-phase refrigerant is not limited to this. For example, the control device 40 may control the operation of the second expansion valve 18 so that the injected refrigerant is a gas-phase refrigerant having a superheat degree, or both the first expansion valve 15 and the second expansion valve 18 are controlled. The operation may be controlled.

Furthermore, if the injected refrigerant can be a vapor phase refrigerant having a superheat degree, an expansion valve or a fixed throttle configured by a mechanical mechanism may be adopted as the first pressure reducing section and the second pressure reducing section. For example, as the first pressure reducing unit, a temperature-sensitive expansion valve that includes a temperature sensing unit having a diaphragm that is displaced according to the temperature and pressure of the refrigerant flowing into the nozzle unit 20a and that changes the throttle opening degree according to the displacement of the diaphragm is used. May be adopted.

(4) The constituent devices that configure the ejector refrigeration cycle 10 to 10c are not limited to those disclosed in the above embodiment.

For example, as the compressor 11, an engine-driven compressor that is driven by the rotational driving force transmitted from the vehicle traveling engine via a pulley, a belt or the like may be adopted. Furthermore, as an engine-driven compressor, it is possible to adjust the refrigerant discharge capacity by changing the capacity of the variable capacity compressor that can adjust the refrigerant discharge capacity by changing the discharge capacity, or by changing the operating rate of the compressor by connecting and disconnecting the electromagnetic clutch. Any fixed capacity compressor can be adopted.

Further, as the radiator 12, a receiver-integrated condenser having a receiver section for separating the gas-liquid of the refrigerant flowing out from the heat exchange section for condensation and storing the separated liquid-phase refrigerant may be adopted. .. Further, a so-called subcool type condenser having a supercooling unit that supercools the liquid-phase refrigerant flowing out from the receiver unit may be adopted.

In addition, as the nozzle-side internal heat exchanger 13 and the suction-side internal heat exchanger 17, a refrigerant pipe forming a high-pressure side refrigerant passage and a refrigerant pipe forming a low-pressure side refrigerant passage are brazed and joined together to form a high-pressure refrigerant. You may employ|adopt the thing of the structure which was able to exchange heat with a low pressure refrigerant. Further, a structure having a plurality of tubes forming the high pressure side refrigerant passage and forming the low pressure side refrigerant passage between adjacent tubes may be adopted.

Further, in the above-described second and third embodiments, the example in which the fixed ejector in which the passage cross-sectional area of the throat (minimum passage area portion) of the high-stage nozzle portion 21a does not change is adopted as the high-stage ejector 21. However, as the high-stage side ejector 21, a variable ejector having a variable nozzle portion capable of adjusting the passage cross-sectional area of the throat may be adopted.

More specifically, as the variable nozzle section, a needle valve that is disposed inside the nozzle section and adjusts the refrigerant passage area of the nozzle section, and an electric drive section that displaces the needle valve in the axial direction of the nozzle section are provided. You may adopt what you have. Then, the control device 40 may control the operation of the drive unit so that the superheat degree SHnoz of the refrigerant flowing into the nozzle portion 20a becomes the reference superheat degree KSHnoz.

According to this, the 1st expansion valve 15 and the high stage side ejector 21 can be integrated substantially, and the 1st expansion valve 15 can be abolished.

Further, in the above-described embodiment, an example in which R134a is adopted as the refrigerant has been described, but the refrigerant is not limited to this. For example, R1234yf, R600a, R410A, R404A, R32, R407C, etc. may be adopted. Alternatively, a mixed refrigerant obtained by mixing plural kinds of these refrigerants may be adopted.

10 to 10c Ejector type refrigeration cycle 11 Compressor 12 Radiator 13 Nozzle side internal heat exchanger (enthalpy rising part)
15 First expansion valve (first decompression section)
16 1st evaporator 17 Suction side internal heat exchanger (enthalpy rising part)
18 2nd expansion valve (2nd decompression part)
19 Second evaporator 20 Ejector

Claims (4)

A compressor (11) for compressing and discharging the refrigerant,
A radiator (12) for radiating the refrigerant discharged from the compressor,
A branch portion (14a) for branching the flow of the refrigerant flowing out from the radiator,
A first pressure reducing portion (15, 21, 23) for reducing the pressure of one of the refrigerant branched by the branching portion;
A first evaporator (16) for evaporating the refrigerant decompressed by the first decompression unit,
A second decompression unit (18) for decompressing the other refrigerant branched at the branching unit,
A second evaporator (19) for evaporating the refrigerant decompressed by the second decompression unit,
The refrigerant that has flowed out from the second evaporator is sucked from the refrigerant suction port (20c) by the suction action of the injected refrigerant that is injected from the nozzle portion (20a) that decompresses the refrigerant that has flowed out from the first evaporator, and the injection is performed. and ejector (20) for boosting by the boosting section (20d) by mixing a suction refrigerant sucked from the refrigerant refrigerant suction port,
An enthalpy raising portion (13, 17) for raising the enthalpy of the refrigerant flowing into the nozzle portion (20a) ,
The enthalpy rising part heat-exchanges the refrigerant flowing out of the radiator with the refrigerant flowing into the nozzle part to heat the refrigerant flowing into the nozzle part, and a nozzle-side internal heat exchanger (13), and A heat sink side internal heat exchanger (17) that heats the refrigerant sucked to the refrigerant suction port by exchanging heat between the refrigerant flowing out from the radiator and the refrigerant sucked to the refrigerant suction port;
An ejector-type refrigeration cycle in which the injected refrigerant is a gas-phase refrigerant having a superheat degree. The nozzle-side internal heat exchanger is a refrigerant that has flowed out of the radiator and is for exchanging heat between the refrigerant on the upstream side of the branch portion and the refrigerant that flows into the nozzle portion,
The suction-side internal heat exchanger is for exchanging heat between the refrigerant flowing out of the radiator and the other refrigerant branched at the branch portion and the refrigerant sucked into the refrigerant suction port. The ejector-type refrigeration cycle described in 1 . The first depressurizing section flows out of the first evaporator by the suction action of the high-stage side injected refrigerant that is injected from the high-stage side nozzle section (21a) that depressurizes one of the refrigerant branched at the branching section. Higher-stage booster that sucks the refrigerant from the higher-stage refrigerant suction port (21c) to mix and raise the higher-stage injection refrigerant and the higher-stage suction refrigerant sucked from the higher-stage refrigerant suction port The ejector type refrigeration cycle according to claim 1 or 2 , further comprising a high-stage ejector (21) having a portion (21d). A pressure reducing control section (40b) for controlling the operation of at least one of the first pressure reducing section and the second pressure reducing section,
The decompression control unit controls at least one of the first decompression unit and the second decompression unit such that the superheat degree (SHnoz) of the refrigerant flowing into the nozzle unit becomes a predetermined reference superheat degree (KSHnoz). The ejector type refrigeration cycle according to any one of claims 1 to 3 , which controls operation.

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