JP3387949B2 - Air conditioning system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioning system, and more particularly to an air conditioning system used in a vehicle refrigerant circuit having a variable capacity refrigerant compressor.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 5 and 6, a control system used in a vehicle refrigerant circuit having a variable capacity refrigerant compressor of this type has a heat exchange in an initial operation of an air conditioning control system. Temperature T'e on the downstream side of the reactor
Is rapidly controlled as shown by the dotted line in the figure.

In FIG. 5 and FIG. 6, during the period from the initial operation time t0 of the refrigerant circuit to the time T'1 when the temperature T'e falls to a temperature T3 slightly higher than the target temperature Tset, the variable capacity of the compressor from the control unit is changed. By means of the output of an electrical signal with amperage Ip1 to the control mechanism, the pressure control point of the compressor suction chamber is kept at a minimum limit value of 1.0 kg / cm2G, which quickly reduces the temperature T'e. When the temperature T'e drops to the temperature T3, the pressure control point of the compressor suction chamber changes.
As a result, the temperature T'e converges on the target temperature Tset by another electric signal having various amperages set by the proportional control operation in the control unit.

[0004]

However, in the initial operation of the conventional air conditioning system described above, the air temperature on the downstream side of the heat exchanger overshoots the target temperature Tset, so that the temperature Te converges to the target temperature Tset. There was a drawback that it took a long time to get there.

As a result, there arises a problem that proper control becomes difficult when the air conditioning system in the vehicle compartment is started.

Therefore, in view of the above-mentioned drawbacks, a technical object of the present invention is to provide an air conditioning system for appropriately controlling the air conditioning of a vehicle compartment or the like from the time of startup.

[0007]

According to the present invention, external control is provided.
And a refrigerant compressor with a variable capacity control mechanism
A heat exchanger connected to the suction chamber of the refrigerant compressor,
Move the air to the refrigerant circuit that has and the outer surface of the heat exchanger
Moving means for controlling and a control mechanism section for controlling the operation thereof
An air conditioning system having:
Detection for detecting the temperature of the air just below the heat exchanger downstream side
Means, and immediately before the refrigerant circuit is activated, the heat exchanger
Of the compressor according to the air temperature immediately below the downstream side of
A first setting of a first pressure control value in the suction chamber
And the heat exchanger during operation of the refrigerant circuit.
One value where the air temperature immediately downstream of the
Determination means for determining higher than, and the refrigerant circuit
During operation, the air temperature immediately below the heat exchanger on the downstream side is
Below one certain value, the suction of the compressor
The pressure control point in the entrance chamber is maintained at the first pressure control value.
The compressor from a first state adjusted to
The pressure control point in the suction chamber of
Change to a second state that is adjusted to change
An air conditioning system is provided which comprises:

[0008]

According to the present invention, in the air conditioning system, the feedback control is proportional control,
An air conditioning system is obtained in which the proportional control includes a value obtained by subtracting the air temperature on the downstream side of the heat exchanger in operation of the cooling circuit from the target temperature.

Further, according to the present invention, in the air conditioning system, an air conditioner for determining whether the air temperature on the downstream side of the heat exchanger immediately before the activation of the cooling circuit is equal to or more than one preset limit value. The system is obtained.

Further, according to the present invention, in the air conditioning system, when the air temperature on the downstream side of the heat exchanger immediately before the activation of the cooling circuit is equal to or lower than the one preset limit value, An air conditioning system is obtained in which the proportional control is activated by the first pressure control value .

Further, according to the present invention, in the air conditioning system, the control mechanism portion is further provided under the heat exchanger.
If the air temperature directly below the flow side is higher,
Depending on the temperature gradient related to the state before reaching the value
The second pressure in the suction chamber of the compressor.
A second setting means for setting a force control value, and if the air temperature on the downstream side of the heat exchanger immediately before the activation of the cooling circuit is equal to or higher than the one preset limit value, the proportional An air conditioning system is obtained in which the control is activated by said second pressure control value .

[0013]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 shows an air conditioning control system for a vehicle refrigerant circuit having a variable capacity refrigerant compressor of this embodiment. Reference numeral 10 is a refrigerant circuit, and 20 is a control mechanism section for controlling the operation of the refrigerant circuit 10. The refrigerant circuit 10 includes a variable capacity refrigerant compressor 11, a condenser 12, an expansion valve 13,
It has a heat exchanger 14. The electromagnetic clutch 111 is fixed to the compressor 11, and by intermittently converting power from the outside, the engine drive 15 of the vehicle causes the drive shaft 111 of the compressor to move.
Activate 1 intermittently. The refrigerant circuit 10 is connected to the condenser blower 121 that works with the condenser 12 to pass air through the outer surface of the condenser 12, and the heat exchanger 14 that works to pass air through the outer surface of the heat exchanger 14. And a blower 141 for the heat exchanger. Each of the blowers 121 and 141 is driven by the electric power from the DC power storage device 16 installed in the engine room of the vehicle. A temperature detector 17, a first initial value setting circuit 21, a first determination circuit 23, a limit value setting circuit 24, a second determination circuit 25, a target value setting circuit 26a, a subtractor 26b,
It comprises a first calculator 28, a second calculator 26c, a second initial control value setting circuit 29, a second switch 27, and an amplifier 30. A temperature detector 17 detects the air temperature Te immediately below the indoor heat exchanger 14 whose outlet is connected to the suction chamber of the compressor during a predetermined time Δt to detect the first electric signal S1. As the first initial control value setting circuit 21
Output to. Further, the temperature detector detects the air temperature Tea on the downstream side of the indoor heat exchanger 14 immediately before the operation of the compressor 11 due to activation of the refrigerant circuit 10 or the like, and outputs it as the second electric signal S2. Furthermore, the first initial control value setting circuit 21 is connected to a first switch unit 22 that activates or terminates the vehicle air conditioning system.

When air cooling inside the vehicle is required,
The first switch 22 activates the heat exchanger blower 141 and the condenser blower 121, and at the same time, the control mechanism unit 20.
Then, the second switch 27 connects the first initial control value setting circuit 21 and the amplifier 30 via the first terminal 27a. After this, the electromagnetic clutch 111 moves to the compressor 1
Start 1. During operation of the compressor 11, the refrigerant pressurized by the condenser 12 with heat exchange is compressed, the refrigerant compressed by the expansion valve 13 expands, and the indoor heat exchanger 14 receives the refrigerant and exchanges heat. To do. After that, the refrigerant that has exchanged heat in the heat exchanger 14 returns to the compressor 11. These are repeatedly executed during the operation of the compressor.

When the control mechanism section 20 is activated, the first initial control value setting circuit 21 processes the second electric signal S2 sent from the temperature detector 17, and the third electric signal having the amperage Ia which changes according to the detected temperature Tea. The signal S3 is set by the method described later.

FIG. 2 is a graph showing the relationship between the amperage of the third electric signal, the pressure control point in the suction chamber of the compressor, and the detected temperature Tea. In the figure, the detected temperature Tea has a preset first limit value T 1 (for example,
In the case of 15 degrees or less, the amperage Ia of the third electric signal S3 is held by the first constant Ic1, and the first constant keeps the pressure control point of the suction chamber of the compressor at 2.5 kg / cm2G. Detection temperature
Tea has a preset second limit value T2 (eg 30 degrees)
In the above case, the amperage Ia of the third electric signal S3 is the second constant
It is held by I c2 and the second constant keeps the pressure control point of the compressor suction chamber at 1.0 kg / cm2G. Also, the detected temperature
When Tea is higher than the preset first limit value T1 and lower than the second limit value T2, the amperage Ia is the first constant Ic.
The first constant of the pressure control point of the compressor suction chamber is 2.5 kg / cm2G and the third constant Ic3 is 1.7 kg / cm.
Adjust to cm2G.

Reference numeral 23 denotes a first discriminating circuit, which represents a second electric signal S2 from the temperature detector 17 and a second electric value T2 preset by the limit value setting circuit 24. Upon receiving the signal S4, it is determined whether the detected temperature Tea is equal to or higher than the second limit value T2.

In this discrimination process, the first discrimination circuit 23
Outputs the discrimination result as a fifth electric signal S5 when the detected temperature Tea is equal to or higher than the second limit value T2, and outputs a sixth electric signal S6 when the detected temperature Tea is lower than the second limit value T2.

Reference numeral 25 is a second discriminating circuit, and the first electric signal S1 from the temperature detector 17 and the target temperature of the air directly below the heat exchanger 14 from the target temperature setting circuit 26a. The seventh electric signal S7, which represents the third limit value T3 higher than Tset by the preset minute value ΔTset, is received, and it is determined whether the detected temperature Te is higher than the third limit value T3. The third limit value T3 generally indicates a value in the range from the first limit value T1 to the second limit value T2.

In this discrimination process, the second discrimination circuit 25
Outputs the determination result as an eighth electric signal S8 when the detected temperature Te is higher than the third limit value T3, and as a ninth electric signal S9 when the detected temperature Te is equal to or lower than the third limit value T.

Numeral 28 is a first calculator which receives the first electric signal S1 indicating the detected temperature Te from the connected temperature detector 17 and calculates it by the following equation (1).

Α (n) = (Te (n) -Te (nm)) / βt (1) where (n) and (nm) are the ordinal numbers of the detected temperature Te and α ( n) is the detected temperature Te (n) from the high side of the third limit value 3 to the third limit value 3
Is a temperature gradient in a preset short time βt just before reaching. In the Te (nm) term, m is an index of βt / ΔT, but since βt is set to a multiple of ΔT, it is a natural number.

The first calculator 28 generates a tenth electric signal S10 representing the thermal gradient α (n) and outputs the tenth electric signal S10 to the second initial control value setting circuit 29. The second initial control value setting circuit 29 outputs the tenth electrical signal S10 as the thermal gradient α (n) from the connected first computing unit 28 from the first initial control value setting circuit 21 to the third electrical signal S. 3 is the first discrimination circuit 23
To process the fifth electric signal S5 and the sixth electric signal S6.

In the course of this processing, when the second initial control value setting circuit receives the signal S6 indicating the comparison result that the detected temperature Tea is less than the second limit value T2, the third electric signal
When the eleventh electrical signal S11 having an amperage Ia that changes according to the change in the detected temperature Tea is equal to S3 and the signal S5 indicating the comparison result that the detected temperature Tea is equal to or higher than the second limit value T2 is received. , And outputs a twelfth electrical signal S12 having an amperage Ia that changes in response to changes in the thermal gradient α (n).
The output of the twelfth electrical signal S12 here is according to the method described later.

In FIG. 3, when the thermal gradient α (n) is equal to or less than the preset first limit value αa (for example, 0.01 degree / second), the amperage Ib of the twelfth electrical signal S12 is the fourth constant Ic4. The fourth constant keeps the pressure control point of the suction chamber of the compressor at 1.5 kg / cm2G. Also, the thermal gradient α (n) is greater than the preset first limit value αa by the second limit value αb.
(E.g. 0.1 degree / second), the amperage Ib of the twelfth electrical signal S12 is held by the fourth constant Ic4, which is the pressure control point of the compressor suction chamber.
Keep at 2.5kg / cm2G. When the thermal gradient α (n) is larger than the preset first limit value αa and smaller than the second limit value αb, the amperage Ib of the twelfth electrical signal S12 is
Varies within the fourth and fifth constant ranges and the pressure control point of the suction chamber of the compressor is adjusted to vary between 2.5 kg / cm2G and 1.5 kg / cm2G. Second initial control value setting circuit 29
Is connected to the second computing unit 26c, and the eleventh electrical signal S11
And the twelfth electrical signal S12 to the second computing unit 26c. Two
6a is a target value (temperature) setting circuit, which is a thirteenth electrical signal S13 indicating the target air temperature Tset on the downstream side of the indoor heat exchanger 14.
Is output to the connected subtractor 26b. Subtractor 2
6b also receives the first electric signal S1 indicating the detected temperature Te from the temperature detector 17, and executes the following subtraction together with the thirteenth electric signal.

ΔTv = Tset−Te (2) Thereafter, the subtractor sends the fourteenth electrical signal S14 indicating ΔTv to the connected second computing unit 26c. Second calculator 26
c performs the following calculation based on the eleventh and twelfth electrical signals from the second initial control value setting circuit 29 and the fourteenth electrical signal from the subtractor 26b.

I (l) = I (l-1) + Kp (ΔTv (l) -ΔTv (l-1)) (3) where Kp is a proportional coefficient. The symbols (l) and (l-1) are the values calculated by the second calculator. Term I while the symbol l is 1
(l-1) is I when the second calculator receives the eleventh electrical signal
When the twelfth electric signal is received, a becomes Ib, and the second calculator outputs the fifteenth electric signal S15 having the variable amperage I (l).

Reference numeral 27 denotes a second switch element, which is the second discriminating circuit 2
Receive the 8th and 9th electrical signals S8 and S9 from 5. Detection temperature
When Te is equal to or lower than the third limit value T3, the second switch element receives the ninth electric signal and connects the second calculator 26c and the amplifier 30 through the terminal 27b, which is a gain obtained by the effect of the amplifier. And the amplified amperage GI
The current having (I (l)) is supplied to the solenoid of the variable capacity compressor 11. On the other hand, the detected temperature Te is the third limit value T3.
If it is higher, the second switch 27 receives the eighth electric signal and the connection between the first initial control value setting circuit 21 and the amplifier 30 is maintained, and the amperage Ia of the third electric signal is GI (Ia) by the amplifier 30. Is amplified to. Then, the current having the amplified amperage GI (Ia) is supplied to the solenoid of the variable capacity compressor 11.

In this embodiment, when the amperage of the supplied current increases, the pressure control point of the suction chamber of the compressor 11 shifts to a higher position. On the contrary, when the amperage decreases, it moves to the lower side. Target value setting circuit 26
The a, the subtractor 26b, and the second calculator 26c execute proportional calculation in the control unit 26.

The operation of the vehicle air conditioning system in this embodiment is as follows. FIG. 4 is a flowchart showing an operating method at the time of starting the vehicle air conditioning system of FIG. First, when it is required to cool the air in the vehicle cabin,
The first switch element 22 is turned on and the air conditioning system is activated (step 201). In step 202, the condenser blower 121 and the indoor heat exchanger blower 141 are activated, and at the same time, the capacity control device 20 is activated, and the second switch 27 causes the first initial control value setting circuit 21 and the amplifier 30 to operate at the first terminal. Connect at 27a and proceed to step 203. In step 203, the second electric signal indicating the detected temperature Te
S2 is sent from the temperature detector 17 to the first initial control value setting circuit 21 and the first determination circuit 23. In step 204, the first initial control value setting circuit 21 processes the second electric signal S2,
As shown in FIG. 2, the third electric signal S3 having the variable amperage Ia is output.

In step 205, while the third electric signal S3 is sent from the first initial control value setting circuit 21 to the amplifier 30, the compressor 11 receives the power sent from the vehicle engine via the electromagnetic clutch 111. When activated, an electric current having an amplified amperage GI (Ia) is supplied to the solenoid of the suction pressure control type variable displacement compressor so that the pressure control point of the suction chamber of the compressor is kept constant. Further, here, when the detected temperature Te is equal to or higher than the preset target temperature T2, the amperage Ia of the third electric signal S3 is held at the second constant value Ic2, and the pressure control point of the suction chamber of the compressor is 1.0 kg / cm
Kept at 2 G. On the other hand, when the detected temperature Te is lower than the target temperature T2, the amperage Ia is kept at a certain value higher than the third constant value Ic3, and as a result, the pressure control point is kept at a certain value higher than 1.7 kg / cm2G. Be drunk

After the processing in step 205, in step 206 the second discriminating circuit 25 compares the detected temperature Te with the third limit value T3, and if the detected temperature Te is higher than the third limit value T3, step 205 If the detected temperature Te is equal to or lower than the third limit value T3, the process proceeds to step 207. In step 207, the second switch 27 connects the second calculator 26c and the amplifier 30 at the terminal 27a, and at the same time, the comparison result of the first discriminating circuit 23 is called again.

In the next step 208, the detected temperature Te is detected based on the comparison result of the first discriminating circuit 23 which is called again.
It is judged whether or not a is less than a preset second limit value T2, and if it is less than, it goes to step 209, and if not, step 210.
Proceed to.

In step 209, the eleventh electric signal S11, which is the same as the third electric signal S3, is supplied to the second initial control value setting circuit 29.
Is transmitted to the second computing unit 26c, and the process proceeds to step 212.

Further, in step 210, the tenth electric signal S10 is output as a result of the calculation by the first calculator 28 of the equation (1), and the process proceeds to step 211.

In step 211, the tenth electrical signal S10 is processed by the second initial control value setting circuit 29 and the twelfth electrical signal S1 is processed.
2 and the twelfth electrical signal is transmitted to the second computing unit 26c.

In step 212, the equation (3) is calculated by the second calculator 26c and becomes a fifteenth electric signal S15 having a variable amperage I (l). The fifteenth electric signal is sent to the second terminal 27b. It is sent to the amplifier 30 via and is amplified. The current having the amplified amperage GI (Ia) is supplied to the solenoid of the variable capacity compressor 11, the pressure control point of the suction chamber of the compressor 11 is adjusted, and the temperature Te converges on the target temperature Tset. Step 212 is repeatedly executed until the vehicle air conditioning system is stopped.

FIG. 5 shows the cooling characteristic when the detected temperature Te is equal to or higher than the preset second limit value T2 when the vehicle air conditioning system is started. The cooling characteristic of the embodiment of the present invention is shown in FIG. Shown in solid lines. In the figure, the refrigerant circuit 1
The pressure control point of the suction chamber of the compressor 11 is the amperage Ia that is the second constant value Ic2 between T0 that represents the start-up time of 0 and T1 that represents when the temperature Te drops to the third limit value T3. It is kept at 1.0 kg / cm2G by a third electrical signal S3 with T3, and therefore the temperature Te drops to the third limit value T3 in a short time up to T1. Once the temperature Te has fallen to the third limit value T3, the pressure control point of the suction chamber of the compressor 11 is adjusted by the proportional control activated by the twelfth electrical signal S12 having a relatively high amperage Ib.

Therefore, when the vehicle air conditioning system is started, the air temperature Te downstream of the indoor heat exchanger 14 is the target temperature.
It quickly drops without overshooting from Tset.

Therefore, the air in the passenger compartment of the vehicle is subjected to more appropriate air conditioning control when the vehicle air conditioning system is started.

FIG. 6 shows the detected temperature of the vehicle air conditioning system.
It represents the cooling characteristics when Te is less than the preset second limit value T2, and the cooling characteristics of the examples of the present invention are shown by solid lines. In the figure, T1 that represents the time when the temperature Te drops to the third limit value T3 from T0 that represents the start-up of the refrigerant circuit 10.
During this time, the pressure control point of the suction chamber of the compressor is kept at a relatively high value by the third electrical signal S3 having a relatively high amperage Ia, so that the temperature Te is smoothly increased to the first point by T1. It falls to the three limit value T3.

Once the temperature Te drops to the T third limit value T3, the pressure control point of the suction chamber of the compressor 11 is controlled by the proportional control started by the eleventh electric signal S11 which is the same as the third electric signal S3. Adjusted.

[0044]

As described above, according to the present invention, the air temperature Te downstream of the indoor heat exchanger smoothly decreases without overshooting from the target temperature Tset when the vehicle air conditioning system is started. To do. Therefore, the air in the vehicle compartment is subjected to more appropriate air conditioning control when the vehicle air conditioning system is activated.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a control mechanism section of a vehicle air conditioning system having a variable capacity refrigerant compressor according to an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the amperage of the third electric signal, the pressure control point in the suction chamber of the compressor, and the detected temperature Tea.

FIG. 3 is a graph showing the relationship between the amperage of the twelfth electrical signal, the pressure control point in the suction chamber of the compressor, and the temperature gradient αn.

4 is a flowchart showing an operating method at the time of starting the vehicle air conditioning system according to the embodiment of the present invention shown in FIG.

5 is a correlation diagram showing a cooling characteristic at the time of starting the vehicle air conditioning system in the case where the air temperature on the downstream side of the heat exchanger is higher than or equal to a certain limit value, and the solid line in FIG.
The cooling characteristics of the vehicle air-conditioning system are indicated by dotted lines, and the cooling characteristics of the vehicle air-conditioning system according to the embodiment of the related art are the same.

FIG. 6 is a correlation diagram showing a cooling characteristic at the time of starting the vehicle air conditioning system when the air temperature on the downstream side of the heat exchanger immediately before the start of the refrigerant circuit is lower than a certain limit value, and the solid line is a diagram. 1 shows the cooling characteristics of the vehicular air conditioning system, and the dotted line shows the cooling characteristics that match the vehicular air conditioning system according to the embodiment of the prior art.

[Explanation of symbols]

10 Refrigerant circuit 11 Variable capacity refrigerant compressor 12 capacitors 13 Expansion valve 14 heat exchanger 15 engine 111 electromagnetic clutch 121 Blower for condenser 141 Heat Exchanger Blower 16 DC battery 17 Temperature detector 20 Control mechanism section 21 First Initial Value Setting Circuit 24 Limit value setting circuit 25 Second discriminating circuit 26a Target value setting circuit 26b Subtractor 27 Second switch 28 First computing unit 29 Second initial control value setting circuit 30 amplifier

Continuation of the front page (56) References JP-A-4-176726 (JP, A) JP-A-4-66321 (JP, A) JP-A-3-63441 (JP, A) JP-A-3-25022 (JP , A) JP-A-1-153324 (JP, A) JP-A 64-49852 (JP, A) JP-A 63-207716 (JP, A) JP-A 62-184916 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B60H 1/32

Claims (5)

(57) [Claims] 1. A variable capacity control mechanism capable of external control is provided.
The refrigerant compressor (11) and the suction of the refrigerant compressor.
Refrigerant circuit having heat exchanger (14) connected to the drawing chamber
(10) and move air to the outer surface of the heat exchanger
Moving means (141) and controller for controlling their operation
An air conditioning system having a structure section (20), wherein the control mechanism section detects the temperature of air immediately below the heat exchanger on the downstream side.
Means (17), immediately before the refrigerant circuit is activated, downstream of the heat exchanger
Depending on the air temperature directly below, the suction of the compressor
_First to set a _first pressure control value (P ₁ ) in the room
Of the setting means (21) of the heat exchanger and directly below the heat exchanger during operation of the refrigerant circuit.
The air temperature is higher than a certain value that is higher than the target temperature.
And a determining means (25) for determining whether the temperature of the heat exchanger is directly below the heat exchanger while the refrigerant circuit is operating.
If the air temperature is below a certain value, the compressor
The pressure control point in the suction chamber of the lesser is the first pressure control.
From the first state, which is adjusted to maintain the
The pressure control point in the suction chamber of the compressor feeds
Second state adjusted to change by back control
And characterized in that it has a change means for changing (27) to
Air conditioning system. 2. The air conditioning system according to claim 1,
The feedback control is proportional control, and the proportional control
Is an empty space on the downstream side of the heat exchanger during operation of the cooling circuit.
Obtained by subtracting the air temperature from the target temperature
An air conditioning system characterized by including a value. 3. The air conditioning system according to claim 1,
Air on the downstream side of the heat exchanger immediately before the activation of the cooling circuit
Determine that temperature is above one preset limit
Separate air conditioning system. 4. The air conditioning system according to claim 3,
Air on the downstream side of the heat exchanger immediately before the activation of the cooling circuit
If the temperature is below the one preset limit value
The proportional control is started by the first pressure control value.
Air conditioning system characterized in that it is. 5. The air conditioning system according to claim 3,
The control mechanism unit is further provided immediately below the heat exchanger on the downstream side.
Air temperature reaches one of the above values from the higher side
Depending on the temperature gradient related to the state before
The second pressure control value (P
₂ ) and a second setting means (29) for setting
The temperature of the air on the downstream side of the heat exchanger immediately before the start of the cooling circuit
If it is greater than or equal to the one preset limit value,
The proportional control is activated by the second pressure control value.
An air conditioning system characterized by