JPH09287850A - Absorption type cold/hot heat generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize control of capacity during cooling operation. SOLUTION: This absorption type cold/hot heat generating device comprises an outdoor machine 100 to control an amount of a water refrigerant flowing from a condenser 4 to a water refrigerant storage chamber 6B of a vaporizer 6 by a water refrigerant proportional valve 11 located in a water refrigerant line 11A; a refrigerant liquid pipe 50 for a secondary refrigerant connected to the lower end of a vaporizing coil 6A in the vaporizer 6 and one or more indoor machines 52 and 53 through a U-shaped piping arranged in a position lower than those of indoor machines 52 and 53 ; a refrigerant pump 57 arranged in a U-shaped piping at the lower end of the refrigerant liquid pipe 50; and a refrigerant gas pipe 51 connected to the upper end of the vaporizing coil 6A and the respective indoor machines 52 and 53. A control means 59 is provided to detect the opening of the valve of the water refrigerant proportional valve 11 by a vaporizer temperature sensor 17 for the vaporizer 6 and finely open the valve at a vaporizer temperature during cooling rated operation and close at a low grade to the high temperature side higher than the temperature of the vaporizer so that the valve opening is controlled in two stages in proportion to the temperature of the vaporizer, and open the valve at a steep grade to the low temperature side lower than the temperature of the vaporizer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner,
In particular, an absorption type cold / heat generating device that is suitable for controlling the valve opening of a water-refrigerant proportional valve for controlling the amount of water-refrigerant from a condenser to an evaporator in two stages and shortening the rise time of cooling at low load Regarding

[0002]

2. Description of the Related Art In a conventional absorption type cold / hot heat generator, which is used for an air conditioner, as shown in FIG. 4, an absorption cold / hot water generator (outdoor unit) 100 and an absorption cold / hot water generator are provided. Cooling tower 42, which is connected to the machine 100 by cooling water pipes 40 and 41 to cool the cooling water, and a cooling water pipe 41
Between the cooling water circulation pump 14 which is installed in the cooling tower 42 and circulates the cooling water from the cooling tower 42 to the absorption chiller-heater 100, and the air in the space which is connected to the absorption chiller-heater 100 by the cold-water pipes 43 and 44 and arranged in the air-conditioned space. An air conditioning indoor unit (indoor unit) (not shown) that performs heat exchange and a secondary refrigerant that is interposed in the cold / hot water pipe 43 and filled in the cold / hot water pipes 43, 44 is absorbed between the cold / hot water unit 100 and the indoor unit for air conditioning. It is configured to include a cold / hot water circulation pump 15 for circulation.

In addition to the cooling tower 42, the absorption chiller-heater 100, which is usually called an outdoor unit for the air conditioning indoor unit, includes a high temperature regenerator 1 for burning fuel and heating the dilute solution with the heat, and this high temperature regenerator. A separator 2 that separates a refrigerant vapor and an intermediate concentrated solution from a dilute solution heated by a regenerator 1, and a low temperature regeneration that heats the intermediate concentrated solution using the separated refrigerant vapor as a heat source to further generate a secondary refrigerant vapor. , A condenser 4 that cools and condenses and liquefies the refrigerant vapor that has passed through the low-temperature regenerator 3 and the secondary refrigerant vapor that has occurred in the low-temperature regenerator 3 to produce a liquid refrigerant, and the liquid produced in the condenser 4. An evaporator 6 that cools the secondary refrigerant in the evaporation coil by dropping and evaporating the refrigerant from the refrigerant distributor 6B on the evaporation coil that is also installed,
The absorber 5 that absorbs the refrigerant vapor evaporated in the evaporator 6 into a concentrated solution to generate a dilute solution, and the dilute solution is pressurized to pass through the heated fluid side of the low temperature solution heat exchanger 8 and the high temperature solution heat exchanger 7 to reach a high temperature. The solution circulation pump 9 which feeds into the regenerator 1, the pipe line 10A which connects the bottom of the separator 2 and the bottom of the evaporator 6 via the cooling / heating switching valve 10 and the heating fluid outlet side of the low temperature solution heat exchanger 8 are absorbed. Concentrated solution pipe 8A connected to the upper part of the vessel 5 and concentrated solution pipe 8A
And a line 13A for connecting the lower part of the absorber 5 via a solution bypass valve 13, and a line for communicating the concentrated solution pipe 8A with a water refrigerant storage chamber 6B installed in the evaporator 5 via an antifreezing valve 12. 12A and an evaporator temperature sensor 17 attached to the water-refrigerant storage chamber 6B for detecting the temperature of the refrigerant in the water-refrigerant storage chamber 6B.
And a water-refrigerant conduit 11A for guiding the liquid refrigerant from the condenser 4 to the water-refrigerant storage chamber 6B, and a water-refrigerant proportional valve 11 interposed in the water-refrigerant conduit 11A.

Further, the intermediate concentrated solution separated by the separator 2 is guided to the low temperature regenerator 3 via the heating fluid side of the high temperature solution heat exchanger 7, and the refrigerant is evaporated in the low temperature regenerator 3 to become a concentrated solution. After that, the pipe line is configured so as to be guided to the concentrated solution pipe 8A via the heating fluid side of the low temperature solution heat exchanger 8. Each of the absorber 5 and the condenser 4 is internally provided with a cooling water coil,
The outlet of the cooling water coil of the absorber 5 is connected to the inlet of the cooling water coil of the condenser 4, the inlet of the cooling water coil of the absorber 5 is the cooling water pipe 41, and the outlet of the cooling water coil of the condenser 4 is Each is connected to the cooling water pipe 40. The cold / hot water pipe 43 is connected to the inlet side of the evaporator coil of the evaporator 6, and the cold / hot water pipe 44 is connected to the outlet side of the evaporator coil of the evaporator 6. A cold water outlet temperature sensor 16 to be detected is mounted.

As the secondary refrigerant that circulates between the indoor unit and the outdoor unit and conveys heat, a fluid that does not change phase, generally a liquid, has been used, but in recent years, the secondary refrigerant is caused to change phase. As a result, a device that increases the amount of heat transfer per unit flow rate has been devised. FIG. 5 shows an example of such a configuration. Among the configurations shown in FIG. 4, the cold / hot water pipes 43, 44 are provided.
Instead, a refrigerant liquid pipe 50 and a refrigerant gas pipe 51 are connected to the lower end and the upper end of the evaporation coil, respectively. Refrigerant liquid pipe 5
0 and the other end of the refrigerant gas pipe 51 are branched by the number of the plurality of indoor units 52, 53 arranged below the evaporation coil, and the branched end of the refrigerant liquid pipe 50 is divided into the indoor units 52, 53. Expansion valve 5 at the lower entrance of each heat exchanger
4, 55, and the branch ends of the refrigerant gas pipes 51 are connected to the upper inlets of the heat exchangers, respectively.
A refrigerant liquid temperature sensor 21 that detects the temperature of the secondary refrigerant and outputs it as an electric signal to the controller 59 is mounted near the connection between the refrigerant liquid pipe 50 and the evaporation coil.

The refrigerant liquid pipe 50 is connected to the indoor units 52 and 53 on the way.
There is a portion arranged at a lower position than that, and a refrigerant pump 57 that pressurizes the refrigerant liquid and sends it to the evaporation coil is attached thereto. A check valve 58 is provided on the discharge side of the refrigerant pump 57, and the outlet side of the check valve 58 and the suction side of the refrigerant pump 57 are connected via a cooling / heating switching valve 56. A refrigerant liquid pipe is filled with HFC-134a as a secondary refrigerant (hereinafter, also simply referred to as a refrigerant) that undergoes a phase change. Since the other configurations are the same as those in the description of FIG. 3, the description thereof will be omitted.

The operation of the air conditioner shown in FIG. 5 during cooling is as follows. The cooling / heating switching valve 56 is opened during cooling. The refrigerant vapor (HFC-134a) is cooled and condensed by the evaporator coil of the evaporator 6 to become a refrigerant liquid, flows downward through the refrigerant liquid pipe 50 by gravity, passes through expansion valves 54 and 55, and flows through the indoor units 52 and 53. Flow into heat exchanger. The refrigerant liquid that has flowed into the heat exchanger evaporates by taking the heat of the air in the air-conditioned space, becomes a refrigerant vapor, rises through the refrigerant gas pipe 51, and flows into the evaporation coil of the evaporator 6. Since the outdoor unit is operated in the cooling mode, the evaporation coil of the evaporator 6 is cooled by the evaporation of the water refrigerant dropped on its surface, and the refrigerant vapor (HFC-134a) flowing into the evaporation coil is condensed. Liquefy. Due to this condensation and liquefaction, the pressure inside the evaporating coil decreases, and the refrigerant vapor evaporated in the heat exchanger of the indoor unit is sucked into the evaporator. Since the refrigerant liquid condensed and liquefied inside the evaporation coil flows into the indoor unit by gravity, the refrigerant during cooling (HFC
-134a) circulates naturally and there is no need to drive the refrigerant by a pump.

When the cooling operation is started, as described above,
The pressure inside the evaporation coil decreases, and the saturated refrigerant vapor in the refrigerant gas pipe flows into the evaporation coil due to the pressure difference. The refrigerant liquid generated by condensation in the evaporation coil flows down in the refrigerant liquid pipe 50 by its own weight, and the head (liquid column) of the refrigerant liquid rises. In order for the natural circulation of the refrigerant to be established, it is sufficient that (refrigerant liquid head)-(refrigerant gas head) is equal to or more than the total pressure loss of the refrigerant circulation path. That is, the natural circulation of the refrigerant is not started until the liquid head satisfying the following equation is formed. This means that the heat load supplied to the evaporator 6 at the start of the cooling operation is small.

[0009]

[Equation 1]

During heating, the cooling / heating switching valve 56 is closed. The refrigerant liquid (HFC-134a) is heated by the evaporation coil of the evaporator 6 to become refrigerant vapor, flows through the refrigerant gas pipe 51 downward, and flows into the heat exchangers of the indoor units 52, 53. The refrigerant vapor that has flowed into the heat exchanger is deprived of heat by the air in the air-conditioned space, condensed and liquefied, becomes a refrigerant liquid, flows downward through the refrigerant liquid pipe, and flows into the refrigerant pump 57 inlet side. The refrigerant liquid is pressurized by the refrigerant pump 57, flows into the evaporation coil of the evaporator 6, and repeats the above cycle. At this time, the outdoor unit is operated in the heating mode, the high-temperature solution separated by the separator 2 is guided to the evaporator 6, and the evaporator coil is heated by this heat.

Cooling water inlet temperature 32
C., cold water outlet temperature 7 ° C. and evaporator temperature 6 ° C. Under this condition, 100% of the cooling capacity is output, but the concentration adjustment mechanism of the water refrigerant is installed and the concentration of the solution is set. Usually, the maximum amount of water refrigerant is stored at a cooling water temperature of 32 ° C., and the water refrigerant is drawn out and the solution is diluted every time the cooling water temperature decreases. The water-refrigerant proportional valve 11 detects the evaporator temperature by the evaporator temperature sensor 17, and proportionally opens the valve opening from fully closed to the evaporator temperature of 6 to 2 ° C. as shown in FIGS. 6 and 7. Control to adjust the amount of water refrigerant. This ensures absorption capacity as the maximum solution concentration at full load, and prevents freezing of the load side such as freezing of the water refrigerant and solution crystallization due to increased absorption capacity at low cooling water temperature and partial load operation. Therefore, by diluting the solution to suppress the increase in absorption capacity and supplying the necessary amount of water refrigerant at the time of partial load, stable operation is performed and the amount of ineffective refrigerant is reduced.

The cold / hot water pump is always operated at the start of the cooling operation, and the evaporator temperature decreases even if the water refrigerant is not supplied to the evaporator side until the water refrigerant accumulates in the water refrigerant storage chamber at the time of cooling start-up. Temperature at which the antifreezing valve 12 operates (1
Since it does not decrease to ℃), there is no problem as the rise time. However, in the natural circulation system using the secondary refrigerant, since there is no power for carrying the secondary refrigerant during cooling, the load on the evaporator side during startup is small. That is, after the start of the cooling operation, the gas in the refrigerant gas pipe and the bubble gas in the refrigerant liquid pipe are sucked into the evaporator and condensed, but after that, the electronic expansion valve of the indoor unit opens and the gas evaporated in the indoor unit is stored outdoors. As shown in FIG. 8, the temperature of the evaporator of the outdoor unit drops to LT1 (1 ° C.) until it flows into the machine, and the antifreezing valve 12 is operated to mix the solution into the water refrigerant circuit. Therefore, this time, the temperature rapidly rises (around 14 ° C.), and the behavior accompanied by a large fluctuation occurs. As a result, the capacity of the evaporator is lost and the pressure fluctuation is increased, so that the natural circulation of the secondary refrigerant cannot be performed smoothly. That is, the followability between the refrigerant liquid temperature and the evaporator temperature is poor.

[0013]

In the conventional absorption type cold / heat generating device, the natural circulation system using the secondary refrigerant is
Since there is no power to carry the secondary refrigerant during cooling, after the cooling operation starts, the gas in the refrigerant gas pipe and the bubble gas in the refrigerant liquid pipe are sucked into the evaporator and condensed, but then the electronic expansion valve of the indoor unit The temperature of the evaporator in the outdoor unit drops to 1 ° C until the gas evaporated in the indoor unit flows out to the outdoor unit, the freeze prevention valve is activated, and the solution is mixed in the water refrigerant circuit. The temperature rises and the behavior with large fluctuations occurs. As a result, the pressure fluctuation also becomes large, which causes a problem that the natural circulation of the secondary refrigerant cannot be performed smoothly.

An object of the present invention is to provide an absorption type cold / heat generating device capable of naturally circulating a secondary refrigerant that changes in phase between an indoor unit and an outdoor unit during cooling to stabilize capacity control during cooling operation. To provide.

[0015]

In order to achieve the above-mentioned object, an absorption type cold / heat generating device according to the present invention includes a regenerator, a condenser, an absorber and an evaporator, and flows from the condenser to the evaporator. An outdoor unit that controls the amount of water refrigerant to be controlled by a water-refrigerant proportional valve provided in the water-refrigerant conduit, and a phase-change secondary refrigerant connected to at least one indoor unit lower than the lower end of the evaporation coil of the evaporator. In the absorption type cold / hot heat generating device including the refrigerant liquid pipe, the refrigerant pump arranged at the lower end of the refrigerant liquid pipe, and the refrigerant gas pipe connected to the respective indoor units from the upper end of the evaporation coil, the water-refrigerant proportional The valve opening degree of the valve is slightly opened at the evaporator temperature during the cooling rated operation, and is controlled in two stages in proportion to the evaporator temperature. Equipped with control means that opens steeply toward the lower temperature side Configured to have.

Further, a water-refrigerant proportional valve for controlling the amount of water-refrigerant is provided between the condenser and the evaporator included in the outdoor unit so that the secondary refrigerant that changes in phase naturally circulates in the evaporation coil of the evaporator. In an absorption type cold / heat generating device in which a refrigerant liquid pipe and a refrigerant gas pipe are connected to at least one indoor unit located at a position lower than the evaporator, the valve opening of the water-refrigerant proportional valve is set to the evaporator temperature during the cooling rated operation. It may be configured such that the control means is provided so as to be slightly opened and controlled in two stages in proportion to the temperature of the evaporator, toward the high temperature side or the low temperature side.

The evaporator temperature during the cooling rated operation is 6 ° C.
The valve opening of the water-refrigerant proportional valve is slightly opened to 5% at 6 ° C, and fully closed to 0% at 12 ° C on the high temperature side.
Further, it may be configured to be fully opened to 100% at 2 ° C. on the low temperature side. The absorption-type cold / hot heat generator according to claim 1 or 2, characterized in that.

Further, the air conditioner is configured to include any one of the absorption type cold / heat generating devices described above.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, a regenerator such as a high temperature regenerator 1 and a low temperature regenerator 3, a separator 2, a condenser 4, an absorber 5, an evaporator 6, a high temperature solution heat exchanger 7 and a low temperature solution heat exchanger 8 An outdoor unit 100 that includes devices such as the above and controls the amount of water refrigerant flowing into the water refrigerant storage chamber 6B of the evaporator 6 from the condenser 4 by the water refrigerant proportional valve 11 provided in the water refrigerant conduit 11A.
And the lower end of the evaporation coil 6A in the evaporator 6 and the indoor unit 52,
Refrigerant liquid pipe 5 for secondary refrigerant connected to one or more indoor units 52, 53 via a U-shaped pipe provided at a position lower than 53.
0, a refrigerant pump 57 arranged in the U-shaped pipe at the lower end of the refrigerant liquid pipe 50, and a refrigerant gas pipe 51 connected to the upper end of the evaporation coil 6A and the respective indoor units 52, 53 In this system, the valve opening of the water-refrigerant proportional valve 11 is detected by the evaporator temperature sensor 17 of the evaporator 6, and the temperature is slightly opened at the evaporator temperature during the cooling rated operation and the evaporator temperature is set. In order to control in two steps in proportion to each other, a control means (controller) 59 that closes at a temperature lower than the evaporator temperature at a lower gradient and opens at a temperature lower than the evaporator temperature at a steep gradient is provided.

As shown in FIG. 2, the evaporator temperature during the cooling rated operation is set to 6 ° C., the valve opening of the water-refrigerant proportional valve 11 is slightly opened to 5% at 6 ° C., and Fully closed to 0% at 12 ° C on the high temperature side and 100% at 2 ° C on the low temperature side
Shall be fully opened.

On the other hand, the secondary refrigerant natural circulation system includes the refrigerant liquid pipe 5 between the refrigerant pump 57 and the respective indoor units 52, 53.
A liquid level switch 70 for detecting the liquid level in the pipe at 0
Is provided, a rising portion 51A protruding from the upper end of the evaporation coil 6A is formed in the refrigerant gas pipe 51, bypass pipes 64A, 64B are provided between the rising portion 51A and the refrigerant liquid pipe 50, and rising pipes 64A, 64B are provided. The refrigerant electromagnetic valve 60 is arranged close to the portion 51A, the refrigerant electromagnetic valve 60 is controlled to be fully opened during heating, and the load is small in the low load to the stopped operation. Therefore, the expansion valves 54, 55 of the indoor units 52, 53 Of the liquid level switch 70 or the outdoor unit 100 due to the decrease in the liquid level due to the reduction in the amount of the refrigerant liquid.
When the combustion in the high temperature regenerator 1 is stopped, the refrigerant pump 57 is stopped, and the refrigerant electromagnetic valve 60 is fully closed under high load operation during cooling.
In addition, a control means (pump controller) 71 for fully opening in a low load operation or a stopped operation is provided.

As described above, the specifications of the water-refrigerant proportional valve 11 are changed so that the control has a two-step proportional range. FIG. 2 and FIG. 3 are examples thereof, in which the slope of the proportional line of the valve opening is changed between the evaporator temperature of 2 to 6 ° C. In this case, 6 ° C. is a so-called design (rating) condition, and if the valve opening is excessively opened at this point, the solution is diluted too much, which causes a problem in securing the capacity of the designed value. A valve opening of about 5% is desirable as a test value. A gentle proportional gradient line is formed between the evaporator temperatures of 6 to 12 ° C, and the water-refrigerant proportional valve 11 is fully closed at 12 ° C or higher. As a result, unlike the conventional method, the water refrigerant is always supplied to the evaporator even when the evaporator temperature is 12 ° C or lower,
The decrease in the evaporator temperature between 6 and 12 ° C. is alleviated, and the refrigerant liquid temperature can follow the evaporator temperature well. Since the fluctuation of the temperature of the refrigerant liquid is reduced, stable operation is achieved, the control on the secondary side is improved, and the natural circulation cycle can be promoted. Therefore, the cooling rise time at a low load is shortened. Also LT1
Even if the anti-freezing valve works due to operation, the evaporator temperature is 6-12 ° C.
Since water refrigerant is supplied during the period, the refrigerating capacity returns faster,
The freezing capacity recovery time is shortened when the antifreezing valve is activated.

[0023]

According to the present invention, the valve opening ratio of the water-refrigerant proportional valve between the condenser and the evaporator is controlled in two stages, and the valve is slightly opened at the evaporator temperature during the rated cooling operation and lowered toward the high temperature side. Since the valve is closed at a gradient, the cooling rise time at a low load can be shortened and the refrigerating capacity recovery time at the time of activation of the antifreezing valve can be shortened.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between an evaporator temperature and a water-refrigerant proportional valve opening degree in the embodiment shown in FIG.

FIG. 3 is a diagram illustrating a relationship between an evaporator temperature and a water refrigerant temperature in the embodiment shown in FIG.

FIG. 4 is a diagram showing a conventional outdoor unit.

FIG. 5 is a diagram showing a conventional technique.

FIG. 6 is a diagram illustrating the operation of the conventional technique.

FIG. 7 is a diagram illustrating an operation of a conventional technique.

FIG. 8 is a diagram illustrating an operation of a conventional technique.

[Explanation of symbols]

1 High Temperature Regenerator 2 Separator 3 Low Temperature Regenerator 4 Condenser 5 Absorber 6 Evaporator 6B Water Refrigerant Storage Room 7 High Temperature Solution Heat Exchanger 8 Low Temperature Solution Heat Exchanger 8A Concentrated Solution Pipe 9 Solution Circulation Pump 10 Cooling / heating Switching Valve 10A Pipeline 11 Water-refrigerant proportional valve 11A Water-refrigerant pipeline 12 Freezing prevention valve 12A Pipeline 13 Solution bypass valve 13A Pipeline 14 Cooling water circulation pump 15 Cold / hot water circulation pump 16 Cold water outlet temperature sensor 17 Evaporator temperature sensor 21 Refrigerant liquid temperature sensor 22 Solution bypass valve 40,41 Cooling water pipe 42 Cooling tower 42A Blower 50 Refrigerant liquid pipe 51 Refrigerant gas pipe 51A Rising part 52,53 Indoor unit 54,55 Expansion valve 56 Cooling / heating switching valve 57 Refrigerant pump 58 Check valve 59 Controller 60 Refrigerant solenoid valve 64A, 64B Bypass pipe 70 Liquid level switch 100 Outdoor unit

Claims (4)

[Claims] 1. An outdoor unit including a regenerator, a condenser, an absorber, and an evaporator, wherein the amount of water refrigerant flowing from the condenser to the evaporator is controlled by a water refrigerant proportional valve provided in a water refrigerant conduit. A refrigerant liquid pipe of a phase-changing secondary refrigerant connected to at least one indoor unit at a position lower than the lower end of the evaporation coil of the evaporator, and a refrigerant pump arranged at the lower end of the refrigerant liquid pipe, In an absorption-type cold / hot heat generator equipped with a refrigerant gas pipe connected to each indoor unit from the upper end of the evaporation coil, the valve opening of the water-refrigerant proportional valve is slightly opened at the evaporator temperature during cooling rated operation. In addition, a control means for closing the evaporator at a temperature lower than the evaporator temperature with a lower gradient and opening the temperature with a steeper gradient to the temperature lower than the evaporator temperature is provided so as to control in two stages in proportion to the evaporator temperature. An absorption type cold / heat generating device characterized by the above. 2. A water-refrigerant proportional valve for controlling the amount of water-refrigerant is provided between a condenser and an evaporator included in the outdoor unit so that a secondary refrigerant that changes phase is naturally circulated in an evaporation coil of the evaporator. In the absorption type cold / heat generating device in which the refrigerant liquid pipe and the refrigerant gas pipe are connected to at least one indoor unit at a position lower than the evaporator, the valve opening degree of the water-refrigerant proportional valve is set in the cooling rated operation. An absorption-type cold / hot heat generator characterized by comprising a control means that opens slightly at the evaporator temperature and controls in two stages to a high temperature side or a low temperature side in proportion to the evaporator temperature. 3. The evaporator temperature during cooling rated operation is set to 6 ° C., the valve opening of the water-refrigerant proportional valve is slightly opened to 5% at 6 ° C., and at the high temperature side of 12 ° C. The absorption type cold / heat generating device according to claim 1 or 2, which is fully closed to 0% and fully opened to 2% at a low temperature of 2 ° C. 4. An air conditioner comprising the absorption-type cold / heat generating device according to claim 1. Description: