JP2002022242A - Refrigerating cycle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control and prevent unnecessary pressure variation of refrigerating cycle caused by the variation of discharge capacity of a compressor. SOLUTION: The valve travel calculated by a valve travel calculating means is corrected or controlled in the case where the discharge capacity calculated by a discharge capacity calculating means matches given conditions. Further, the valve travel is calculated by the valve travel calculating means taking into account the discharge capacity calculated by the discharge capacity calculating means. Furthermore, the valve travel is calculated as a calculation factor which is of the discharge capacity calculating means for calculating the discharge capacity of the compressor, as a factor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor using carbon dioxide as a refrigerant and having a discharge capacity changed by a control signal from the outside, a radiator for cooling a high-pressure refrigerant discharged from the compressor, While reducing the pressure of the refrigerant cooled by the radiator, the valve opening degree is changed by an external control signal, an electric expansion valve, and an evaporator that evaporates the low-pressure refrigerant flowing out of the expansion valve. The present invention relates to a refrigeration cycle control device that controls a refrigeration cycle constituted at least by the above.

[0002]

2. Description of the Related Art A supercritical refrigeration cycle disclosed in Japanese Patent Application Laid-Open No. 11-304268 discloses a variable displacement compressor configured to reduce the amount of refrigerant discharged in response to a decrease in suction pressure. A radiator that cools the refrigerant discharged from the type compressor, an electric expansion valve that is disposed on the outlet side of the radiator and whose valve opening is variably controlled, and a refrigerant that flows out of the electric expansion valve An evaporator for evaporating, and in a supercritical refrigeration cycle in which the high-pressure side refrigerant is compressed to a supercritical region, when the amount of refrigerant discharged from the variable displacement compressor changes (reduces), When the opening degree of the expansion valve is fixed for a predetermined time, and when the discharged refrigerant amount does not change, the valve opening degree of the electric expansion valve is changed so that the refrigerant temperature and pressure at the outlet side of the radiator change along the optimal control line. To control It is intended.

[0003]

In general, in a refrigeration cycle using a carbon dioxide refrigerant as a refrigerant having a variable displacement compressor and an electric expansion valve, if the compressor has a small discharge capacity in order to adjust the refrigeration capacity, the outlet of the radiator is required. Side refrigerant pressure drops. On the other hand, the expansion valve attempts to increase the refrigerant pressure on the outlet side of the radiator by reducing the valve opening so as to maintain a pressure corresponding to the refrigerant temperature on the outlet side of the radiator. As described above, the compressor controls the discharge capacity in accordance with the required refrigerating capacity, while the expansion valve controls the high pressure in accordance with the refrigerant temperature at the outlet of the radiator. The simple control of the combination does not provide the appropriate control.

In order to solve the above problem, Japanese Patent Laid-Open No.
In the refrigeration cycle according to JP-A-304268, the variable displacement compressor is less affected by the expansion valve, and the refrigeration cycle is appropriately controlled. There is a problem that there is a time delay before the suction pressure changes and the time is not constant, so that an erroneous determination may be made.
For example, since the pressure change is not transmitted immediately after the compressor changes the discharge capacity, it is determined that the pressure change is small and the expansion valve is driven, and immediately after the pressure changes, the entire cycle is unnecessarily changed. The problem described above occurs. Furthermore, since the pressure sensor for detecting the suction pressure is expensive, there is a problem that the cost of the system is increased.

Accordingly, an object of the present invention is to provide a refrigeration cycle control device capable of suppressing and preventing unnecessary pressure fluctuations of a refrigeration cycle due to a change in the displacement of a compressor.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a compressor whose discharge capacity is changed by an external control signal, a radiator for cooling the high-pressure refrigerant discharged from the compressor, and a radiator for cooling. A refrigeration cycle comprising at least an expansion means for lowering the pressure of the supplied refrigerant and a valve opening variable by an external control signal, and an evaporator for evaporating the low-pressure refrigerant flowing out of the expansion means. In the above, at least comprises a compressor displacement control means for changing the displacement of the compressor, and a valve opening control means for controlling the valve opening of the expansion means, the control signal to the valve opening control means, The correction is performed based on a control signal output to the compressor capacity control means.

Specifically, as shown in FIG. 1, the refrigeration cycle control device includes an air temperature setting means 30 for setting a target temperature of the air passing through the evaporator, and an air temperature setting means 30 for controlling the air passing through the evaporator. Air temperature detecting means 15 for detecting temperature
A refrigerant temperature detecting means 13 for detecting a refrigerant temperature in a high pressure line from a discharge side of the compressor 2 to an inflow side of the expansion means 5; a high pressure detecting means 14 for detecting a pressure in the high pressure line; Discharge capacity calculating means 32 for calculating the discharge capacity of the compressor 2 based on the target temperature set by the temperature setting means 30 and the actual temperature detected by the air temperature detecting means 15;
A compressor capacity control means 34 for outputting a control signal to the compressor 2 based on the discharge capacity calculated by the discharge capacity calculation means 32;
And a target high-pressure calculating means 36 for calculating a target high-pressure based on the refrigerant temperature detected by the high-pressure detecting means 14 and an actual high-pressure detected by the high-pressure detecting means 14 and a target high-pressure calculated by the target high-pressure calculating means 36. A valve opening calculating means 38 for calculating a valve opening of the expansion means 5 based on the above, a discharge capacity determining means 40 for determining a state of the discharge capacity calculated by the discharge capacity calculating means 32,
A valve opening correction means for correcting the valve opening calculated by the valve opening calculation means when the state of the discharge capacity detected by the discharge capacity determination means matches a predetermined condition; A valve opening control means 44 for outputting a control signal to the expansion means 5 based on the valve opening corrected by the opening correction means 42 is provided.

Thus, according to the present invention, the valve opening calculated by the valve opening calculating means 38 is corrected when the discharge capacity calculated by the discharge capacity calculating means 32 matches a predetermined condition. Therefore, since the expansion means 5 can be controlled by the corrected valve opening at the same time as the discharge capacity control of the compressor 2 by the compressor capacity control means 34, control delay of the expansion means 5 can be prevented, and appropriate refrigeration cycle control can be performed. Can be achieved.

The discharge capacity determining means 40 determines whether or not the change in the discharge capacity calculated by the discharge capacity calculating means 32 is within a predetermined range. When the change in the discharge capacity is determined to be within a predetermined range by the discharge capacity determination means 40, the valve opening calculated by the valve opening calculation means 38 is output to the valve opening control means 44. If the change in the discharge capacity is determined to be outside the predetermined range by the discharge capacity determination means 40, the valve opening calculated by the valve opening calculation means 38 is invalidated. Is desirable.

In this case, the opening degree of the expansion valve is fixed with respect to a sudden change in the discharge capacity. Therefore, the refrigeration cycle is controlled only by the discharge capacity by the compressor, and the refrigeration cycle is controlled by the sudden change in the discharge capacity. The cycle can be stabilized quickly. Also, after the change in the discharge capacity has stabilized,
Since the control of the expansion valve is performed, problems due to hunting of both controls can be prevented.

Further, the discharge capacity determination means 40 determines whether or not the change in the discharge capacity calculated by the discharge capacity calculation means 32 is within a predetermined range. When the change in the discharge capacity is determined to be within a predetermined range by the discharge capacity determination means 40, the valve opening calculated by the valve opening calculation means 38 is output to the valve opening control means 44. If the discharge capacity determining means 40 determines that the change in the discharge capacity is out of the predetermined range in the increasing direction, the valve opening calculated by the valve opening calculating means 38 is determined by a predetermined ratio. When the displacement is determined to be outside the predetermined range in the direction in which the change in the discharge capacity is reduced by the discharge capacity determination means 40, the valve is controlled. Opening calculation means The valve opening control means 44 the valve opening degree calculated by the 8 is corrected to the closing direction at a predetermined ratio
May be output.

In this case, when the change in the discharge capacity of the compressor is out of the predetermined range in the increasing direction, the valve opening is corrected in the opening direction to suppress the increase in the high-pressure pressure, and the discharge capacity of the compressor is reduced. If the change falls outside the predetermined range in the decreasing direction, the valve opening can be corrected in the closing direction to suppress the decrease in the high-pressure pressure. High-voltage fluctuations can be suppressed and control can be stabilized.

Further, as shown in FIG. 2, the refrigeration cycle control device has an air temperature setting means 30 for setting a target temperature of the air passing through the evaporator, and detects a temperature of the air passing through the evaporator. Temperature detection means 15 for detecting the temperature of the refrigerant in a high pressure line from the discharge side of the compressor 2 to the inflow side of the expansion means 5, and high pressure detection for detecting the pressure in the high pressure line Means 14 based on the target temperature set by the air temperature setting means 30 and the actual temperature detected by the air temperature detecting means 15.
Discharge capacity calculation means 32 for calculating the target discharge capacity of the compressor, compressor capacity control means 34 for outputting a control signal to the compressor 2 based on the target discharge capacity calculated by the discharge capacity calculation means 32, and refrigerant temperature detection A target high pressure calculating means 36 for calculating a target high pressure based on the refrigerant temperature detected by the means 13; and an actual high pressure detected by the high pressure detecting means 14 and a target high pressure calculated by the target high pressure calculating means. And a valve opening calculating means 38 for calculating the valve opening of the expansion means 5 in consideration of the compressor discharge capacity calculated by the discharging capacity calculating means 32, and a calculation by the valve opening calculating means 38. And a valve opening control means 44 for outputting a control signal to the expansion means 5 based on the determined valve opening. Good. As described above, according to the configuration shown in FIG. 2, the compressor displacement is directly taken into account as a calculation factor of the valve opening calculator 38, and an appropriate valve opening corresponding to a change in the compressor discharge capacity is calculated. Therefore, it is possible to execute the optimal valve opening control with respect to the variation in the displacement of the compressor 2.

Further, the present invention provides a compressor whose discharge capacity is changed by an external control signal, a radiator for cooling high-pressure refrigerant discharged from the compressor,
The expansion means in which the pressure of the refrigerant cooled by the radiator is reduced and the valve opening degree is changed by an external control signal, and at least an evaporator that evaporates the low-pressure refrigerant flowing out of the expansion means, In the refrigeration cycle configured, the compressor includes at least compressor displacement control means for changing the displacement of the compressor, and valve opening control means for controlling a valve opening degree of the expansion means. The control signal is regulated based on a calculation factor of the compressor capacity calculation means.
Thus, the valve opening calculated by the valve opening calculating means based on the calculation factor of the discharge capacity of the compressor by the compressor capacity calculating means can be regulated, so that the same effect as the above-described invention can be obtained. You can do it.

Specifically, as shown in FIG. 3, the refrigeration cycle control device includes an air temperature setting means 30 for setting a target temperature of the air passing through the evaporator, and an air temperature setting means 30 for controlling the air passing through the evaporator. Air temperature detecting means 15 for detecting temperature
And a temperature difference calculating means 46 for calculating a temperature difference between the target temperature set by the air temperature setting means 30 and the actual air temperature detected by the air temperature detecting means 15.
A discharge capacity calculating means 32 for calculating a discharge capacity of the compressor 2 based on a target temperature set by the air temperature setting means 46 and an actual temperature detected by the air temperature detecting means 15; A discharge capacity regulating means 48 for regulating the discharge capacity calculated by the discharge capacity calculating means 32 based on the temperature difference calculated by the difference calculating means 46, and a discharge capacity regulated by the discharge capacity restricting means 48. And a compressor capacity control means for outputting a control signal to the compressor.

Further, the refrigeration cycle control device includes an air temperature setting means 30 for setting a target temperature of the air passing through the evaporator, and an air temperature detecting means 15 for detecting the temperature of the air passing through the evaporator. , The air temperature setting means 3
A temperature difference calculating means 46 for calculating a temperature difference between the target temperature set by 0 and the actual air temperature detected by the air temperature detecting means 15; and a discharge side of the compressor 2 to an inflow side of the expansion means 5 Refrigerant temperature detecting means 13 for detecting the refrigerant temperature of the high pressure line leading to, high pressure pressure detecting means 14 for detecting the pressure of the high pressure line, and a target high pressure based on the refrigerant temperature detected by the refrigerant temperature detecting means 13. Target high pressure calculating means 36 for calculating
A valve opening calculating means 38 for calculating a valve opening of the expansion means 5 based on the actual high pressure detected by the high pressure detecting means 14 and the target high pressure calculated by the target high pressure calculating means 36; A valve opening restriction means for restricting the valve opening calculated by the valve opening calculation means based on the temperature difference calculated by the temperature difference calculation means; And a valve opening control means 44 for outputting a control signal to the expansion means 5 based on the determined valve opening.

Still further, the present invention provides an air temperature setting means for setting a target temperature of air passing through the evaporator.
Air temperature detecting means 15 for detecting the temperature of air passing through the evaporator; and a target temperature set by the air temperature setting means 30 and an actual air temperature detected by the air temperature detecting means 15. Temperature difference calculating means 46 for calculating a temperature difference; refrigerant temperature detecting means 13 for detecting a refrigerant temperature in a high pressure line from the discharge side of the compressor 2 to the inflow side of the expansion means 5; And a discharge capacity calculation for calculating a discharge capacity of the compressor 2 based on a target temperature set by the air temperature setting means 30 and an actual temperature detected by the air temperature detection means 15. Means 32 and a discharge calculated by the discharge capacity calculating means 32 based on the temperature difference calculated by the temperature difference calculating means 46. Discharge capacity regulation means for regulating the amount 4
8, a compressor capacity control means 34 for outputting a control signal for the compressor 2 based on the discharge capacity regulated by the discharge capacity regulation means 48, and a target based on the refrigerant temperature detected by the refrigerant temperature detection means 13. The target high pressure calculating means 36 for calculating the high pressure, and the valve opening of the expansion means 5 based on the actual high pressure detected by the high pressure detecting means 14 and the target high pressure calculated by the target high pressure calculating means 36. And a valve opening regulating means for regulating the valve opening calculated by the valve opening calculating means based on the temperature difference calculated by the temperature difference calculating means. 50
And a valve opening control means 44 for outputting a control signal to the expansion means 5 based on the valve opening corrected by the valve opening restriction means 50.

The discharge capacity control means 48 calculates the discharge capacity calculation means 32 based on an upper limit value and a lower limit value set in accordance with the temperature difference calculated by the temperature difference calculation means 46. If the discharged displacement is equal to or greater than the upper limit, the upper limit is output to the compressor displacement control means 34 as the displacement, and the discharge displacement calculated by the discharge displacement calculating means 32 is equal to or less than the lower limit. Preferably, the lower limit value is output to the compressor capacity control means 34 as a discharge capacity. Further, the valve opening regulating means 50 responds to the temperature difference calculated by the temperature difference calculation means 46. If the valve opening calculated by the valve opening calculating means 38 based on the set upper limit and lower limit is equal to or larger than the upper limit, the upper limit is set. Is output to the valve opening control means 44 as a valve opening. When the valve opening calculated by the valve opening calculating means 38 is equal to or smaller than the lower limit, the lower limit is set as the valve opening and the valve is set as the valve opening. The information may be output to the opening control means 44.

As described above, according to the configuration as shown in FIG. 3, the upper limit of the valve opening is determined based on the temperature between the target temperature and the actual temperature of the evaporator as a factor for calculating the discharge capacity of the compressor 2. The value and the lower limit are determined, and the valve opening of the expansion means 5 is controlled within the range of the upper limit and the lower limit. The operation can be suppressed, and the above problem can be achieved.

Further, as shown in FIG. 4, the present invention provides a compressor 2 whose discharge capacity is changed by an external control signal, a radiator for cooling high-pressure refrigerant discharged from the compressor, and a radiator Means for lowering the pressure of the refrigerant cooled by the cooling means, and the opening degree of the valve is changed by an external control signal, and an evaporator for evaporating the low-pressure refrigerant flowing out of the expansion means 5 Environmental load signal,
For example, based on the setting signal from the vehicle interior temperature setting means 20, the indoor temperature signal from the indoor temperature detecting means 16, the outside air temperature detecting signal from the outside air temperature detecting means 17, the solar radiation signal from the solar radiation detecting means 18, etc. And a target air temperature calculating means 5 for calculating a target temperature of the air blown out of the evaporator from the target blowing temperature calculated by the target blowing temperature calculating means 52.
4, an air temperature detecting means 15 for detecting the temperature of the air passing through the evaporator, and a target air temperature calculated by the target air temperature calculating means 54 and an actual temperature detected by the air temperature detecting means 15. And a discharge capacity calculating means 32 for calculating the discharge capacity of the compressor 2 on the basis of the target discharge temperature calculated by the target discharge temperature calculating means 52.
2 includes a discharge capacity regulating means 48 for regulating the discharge capacity calculated by the compressor 2 and a compressor capacity control means 34 for outputting a control signal to the compressor 2 based on the discharge capacity regulated by the discharge capacity regulating means 48. It is in.

Further, the present invention provides a target outlet temperature calculating means 52 for calculating a target outlet temperature based on an environmental load signal.
A target air temperature calculating means 54 for calculating a target temperature of the air blown from the evaporator from the target blow temperature calculated by the target blow temperature calculating means 52; and an air for detecting the temperature of the air passing through the evaporator. Temperature detection means 15
A refrigerant temperature detecting means 13 for detecting a refrigerant temperature in a high pressure line from a discharge side of the compressor 2 to an inflow side of the expansion means 5; a high pressure detection means 14 for detecting a pressure in the high pressure line; A target high pressure calculating means for calculating a target high pressure based on the refrigerant temperature detected by the temperature detecting means;
Opening degree calculating means 38 for calculating the valve opening degree of the expansion means 5 on the basis of the actual high pressure detected by the above and the target high pressure calculated by the target high pressure calculating means 36.
A valve opening regulating means 50 for regulating the valve opening calculated by the valve opening calculating means 38 to a predetermined value based on the target blowing temperature calculated by the target blowing temperature calculating means 52; A valve opening control means 44 for outputting a control signal to the expansion means 5 based on the valve opening corrected by the valve opening regulating means 50 is provided.

Further, according to the present invention, there is provided a target outlet temperature calculating means 52 for calculating a target outlet temperature based on an environmental load signal, and air is blown out of the evaporator from the target outlet temperature calculated by the target outlet temperature calculating means 52. Target air temperature calculating means 54 for calculating a target temperature of air; and air temperature detecting means 1 for detecting a temperature of air passing through the evaporator.
5 and the expansion means 5 from the discharge side of the compressor 2.
Refrigerant temperature detecting means 13 for detecting the refrigerant temperature of the high pressure line reaching the inflow side of the refrigerant, high pressure pressure detecting means 14 for detecting the pressure of the high pressure line, and the target air temperature calculating means 52
Discharge capacity calculating means 3 for calculating the discharge capacity of the compressor 2 based on the target air temperature calculated by the above and the actual temperature detected by the air temperature detecting means.
2 and the target discharge temperature calculated by the target discharge temperature calculation means 52, the discharge capacity calculation means 32
A displacement control means that regulates the discharge capacity calculated by the compressor, a compressor displacement control means that outputs a control signal to the compressor 2 based on the discharge capacity regulated by the discharge capacity regulation means, The target high pressure calculating means 36 for calculating the target high pressure based on the refrigerant temperature detected by the detecting means 13, and the actual high pressure detected by the high pressure detecting means 14 and the target high pressure calculated by the target high pressure calculating means 36. The valve opening degree calculating means 38 for calculating the valve opening degree of the expansion means 5 based on the target high pressure, and the valve opening degree calculating means 38 based on the target outlet temperature calculated by the target outlet temperature calculating means. A valve opening restriction means for restricting the calculated valve opening to a predetermined value; and a valve opening corrected by the valve opening restriction means. In that it comprises a valve opening control means 44 for outputting a control signal to said expansion means based on.

The discharge capacity regulating means 48 calculates the upper limit value and the lower limit value corresponding to the target blow temperature calculated by the target blow temperature means 52 by the discharge capacity calculating means 32. If the calculated discharge capacity is equal to or greater than the upper limit value, the upper limit value is output as the discharge capacity to the compressor capacity control means 34, and the discharge capacity calculated by the discharge capacity calculation means 32 is equal to or less than the lower limit value. In this case, it is desirable to output the lower limit value as the discharge capacity to the compressor capacity control means 34, and the valve opening degree control means 50 corresponds to the target blow temperature calculated by the target blow temperature calculating means 52. If the valve opening calculated by the valve opening calculating means 38 based on the upper limit and the lower limit set as above is greater than or equal to the upper limit, The outputs the upper limit value to the valve opening control means 44 as a valve opening, the valve opening calculating means 3
If the valve opening calculated by step 8 is equal to or less than the lower limit, the lower limit is regarded as the valve opening and the valve opening control means 44 is used.
May be output.

As described above, according to the configuration shown in FIG. 4, the upper limit value and the lower limit value of the valve opening are determined based on the target blow-out temperature calculated by the heat load signal as a factor for calculating the discharge capacity of the compressor 2. In addition, the valve opening of the expansion means 5 is controlled within the range of the upper limit value and the lower limit value, so that the valve operation that fluctuates in response to a change in high pressure due to a rapid change in the discharge capacity can be suppressed. The above object can be achieved similarly to the above-described configuration.

[0025]

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

The refrigeration cycle 1 shown in FIG. 5 uses a supercritical refrigerant such as carbon dioxide as a refrigerant. The refrigeration cycle 1 has a variable displacement mechanism 9 for varying the discharge capacity based on the pressure on the low pressure side. A variable displacement compressor 2 whose on / off is controlled by an electromagnetic clutch 8 using an engine for driving as a drive source. The refrigeration cycle 1 has a radiator 3 for cooling the refrigerant compressed to a supercritical region by the compressor 2, and an outlet side of the radiator 3 has a high-pressure side constituting an internal heat exchanger 4. The high-pressure refrigerant passing through the heat exchanger 4a is cooled by the low-pressure refrigerant. An electric expansion valve (hereinafter, expansion valve) 5 whose opening degree is adjusted by a control signal from the control unit 10 is provided on the outflow side of the high-pressure side heat exchanger 4a. The path from the discharge side of the compressor 2 to the inflow side of the electric expansion valve 5 is a high-pressure line 1.
1.

On the outflow side of the expansion valve 5, the expansion valve 5
An evaporator 6 is provided for evaporating the refrigerant which has been throttled down and reduced in pressure to the gas-liquid mixing region. The evaporator 6 absorbs heat of air passing through the air conditioning duct 22 and cools the air. On the outflow side of the evaporator 6, an accumulator 7 is provided. The accumulator 7 performs gas-liquid separation to supply only the gas phase component of the refrigerant to the compressor 2 and adjusts the amount of the refrigerant circulating in the refrigeration cycle 1. The refrigerant flowing out of the accumulator 7 is heated by the heat of the high-pressure refrigerant by passing through the low-pressure side heat exchanger 4b of the internal heat exchanger 4, and is sucked into the compressor 2. The path from the outflow side of the expansion valve 5 to the suction side of the compressor 2 forms a low-pressure line 12.

A control unit 10 is provided to control the refrigeration cycle 1 having the above configuration. The control unit 10 is a known unit that includes at least a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), an input / output port (I / O), and the like. 11, a refrigerant temperature sensor 13 for detecting the temperature (Tref) of the high-pressure refrigerant, a pressure sensor 14 for detecting the pressure (PH) of the high-pressure refrigerant, and a blowing temperature (Teva) of the evaporator 6. ), An indoor temperature sensor 16 for detecting a vehicle interior temperature (Tinc), an outdoor air temperature sensor 17 for detecting an outdoor air temperature (Tam), a solar radiation sensor 18 for detecting an amount of solar radiation (Qsun), and , Temperature setting switch 2 on operation panel 19
At least a temperature setting signal (Tptc) from 0, an on / off signal from an A / C switch 21 for controlling on / off of the electromagnetic clutch 8, and a setting signal (Teva_set) from a volume switch 30 for setting an evaporator temperature are input. This is processed by a predetermined program as shown in the flowchart, and is output as a control signal to the electromagnetic clutch 8, the variable displacement mechanism 9, the expansion valve 5, and the like.

Hereinafter, control according to the embodiment of the present invention, which is executed in the control unit 10, will be described with reference to respective flowcharts.

FIG. 6 shows a basic flowchart 100 of the refrigeration cycle control. This flowchart 1
00 is, for example, periodically started from the main control routine of the air conditioning control. In step 110, initialization of various signals can be performed, and in step 120, signal processing calculation is performed. In the signal processing calculation in step 120, each of the sensors 13, 14, 15, 16,
The signals from 17, 18 and the setting signal from the operation panel 19 are read and processed into operation signals which can be calculated, and the target outlet temperature (Tao) is calculated in step 122 shown in FIG. The calculation of the target outlet temperature Tao is performed by using, for example, a mathematical expression shown in step 124. In the equation shown in this step 124, T'ptc is the temperature setting switch 20
Is a temperature setting signal calculated from a temperature setting signal Tptc from the solar radiation sensor, Q'sun is a solar radiation amount signal calculated from the solar radiation signal Qsun from the solar radiation sensor 18, and A, B,
C and D are arithmetic constants for weighting the respective signals, and E is a correction term. In the above configuration, an evaporator temperature setting volume is provided on the operation panel 19 to set the evaporator temperature. However, in this step, a target value of the evaporator temperature may be calculated from the target outlet temperature Tao. Things.

Then, after step 120, step 2
At 00, control of the electromagnetic clutch 8 (Mgcl control) as shown in FIG. 8 is executed. In this electromagnetic clutch control, at step 202, the A / C
Whether the switch 21 is turned on (A / C SW
ON)), and if the A / C switch 21 is not turned on (N), the routine proceeds to step 216, where the compressor 2 is turned off (COMP OFF), and the energization to the electromagnetic clutch 8 is stopped. Then, the connection to the driving engine (not shown) is cut off, and the compressor 2 is stopped.

If it is determined in step 202 that the A / C switch 21 is turned on, then in step 204, the high pressure PH of the refrigeration cycle 1 is increased to a predetermined pressure range P3 to P4 (for example, , 11M
It is determined whether the pressure is equal to or higher than Pa to 15 MPa). If the high pressure is higher than a predetermined pressure (A), the process proceeds to step 216 to stop the compressor 2 for safety. In addition, the high pressure PH is in the predetermined pressure range P3.
If the pressure is equal to or less than P4 (B), the routine proceeds to step 206, where it is determined whether or not the high pressure PH is within a predetermined pressure range P1 to P2 (for example, 3.5 MPa to 3.9 MPa). If it is determined in step 206 that the high pressure PH is equal to or less than the predetermined pressure range P1 to P2 (D), it is determined that the refrigerant is insufficient, and step 216 is performed.
Then, the compressor 2 is stopped. If it is determined in step 206 that the high pressure PH is equal to or higher than the predetermined pressure range (C), the process proceeds to step 208 to determine the actual evaporator temperature (Teva). In this determination, the evaporator temperature (Teva)
Is equal to or lower than a predetermined temperature T1 (for example, 1.5 ° C.), it is determined that the evaporator temperature is low, and the predetermined temperature T1 is determined.
In the case of 1 or more, it is determined that the evaporator temperature is high. In this determination, hysteresis is formed, and the temperature range Th is, for example, 2.5 ° C. The result of this determination is determined in step 210, and if it is determined that the evaporator temperature (Teva) is low, the process proceeds to step 212, where the operation of the compressor 2 is continued for a time t1 (for example, 60 seconds), and the operation is continued for a time t1 Step 2 after lapse
Proceeding to 16, the compressor 2 is stopped. If the evaporator temperature (Teva) is not low in the determination in step 210, the process proceeds to step 214, where the operation of the compressor 2 is set (COMP ON), and the electromagnetic clutch 8 The compressor 2 is operated by being energized and connected to a running engine (not shown).

After the electromagnetic clutch control of the compressor 2, the control of the capacity of the compressor 2 is executed at step 300. The capacity control of the compressor 2
For example, as shown in FIG.
It is determined whether the C switch 21 is turned on. If the switch is not turned on (N), the process proceeds to step 304, where the proportional component D of the capacity control duty ratio D output to the capacity control mechanism 9 is output.
p is set to “0”, and further proceeds to step 306, where the integral component Di (t
−Δt) is set to “0”, and in step 308, the capacity control duty ratio D is set to “0”.
At 80, the capacity control duty ratio D is output. still,
In this case, the capacity control duty ratio D is not substantially output. Further, in the capacity control duty ratio D, when the duty ratio is 0 [%], the valve of the capacity control mechanism 9 is fully opened, high pressure is introduced into the back pressure chamber (not shown) of the compressor 2 and the minimum capacity is obtained. Is 100
At the time of [%], the valve is fully closed and high pressure is not introduced into the back pressure chamber, so that the maximum capacity is obtained.

If it is determined in step 302 that the A / C switch 21 is turned on (Y), the process proceeds to step 310, where the evaporator temperature setting volume switch (EVA temperature setting VR) 3
Target evaporator temperature Teva_s according to level of 0
et is set. In step 310, Te
1 is set to 2 ° C., and Te 2 is set to 15 ° C. In this step 310, the evaporator temperature is set manually by the evaporator temperature setting volume switch 30, but may be obtained based on the above-described target blowout temperature (Tao). In this case, the target evaporator temperature Teva_set is 2 ° C. when the target blowout temperature Tao is 10 ° C., and the target blowout temperature Tao is 30 ° C. in the characteristic line shown in the block of step 310.
The target evaporator temperature Teva_set is 15 ° C
It is desirable that

Then, the routine proceeds to step 320, where the capacity calculation duty ratio (0 to 100%) DT is calculated. The calculation of the capacity calculation duty ratio DT is, for example, as shown in FIG. 10. First, in step 322, the proportional component Dp of the capacity calculation duty ratio DT is calculated. This proportional component Dp is calculated from the temperature difference between the actual evaporator temperature Teva and the target evaporator temperature Teva_set set in the step 310 by the characteristic line shown in FIG. Basically, based on a primary characteristic line that changes such that the proportional component Dp becomes “0%” when the temperature difference is −20 ° C. and the proportional component Dp becomes “100%” when the temperature is + 20 ° C. The proportional component Dp is calculated from the temperature difference.

Further, in step 324, FIG.
The temperature difference (Teva-Tev) based on the characteristic line shown in FIG.
a_set), a change ΔDi of the integral component is calculated. Then, at step 326, the t-time integral component D
i (t) is calculated by the equation {Di (t)
= Di (t-Δt) + ΔDi｝.
Note that this Δt is 100 msec.

Then, at step 328, it is determined whether or not the t-time integral component Di (t) is 50% or more.
A determination is made whether i (t) is less than or equal to -50%. In the above determination, the t-time integral component Di
If (t) is 50% or more, step 32
8, the flow advances to step 332 to set the integral component Di to 50.
[%], And the t-time integral component Di (t) is −5.
If it is not more than 0 [%], the process proceeds from step 330 to step 334 to limit the integral component Di to -50 [%]. Further, the t time integral component Di (t) is -50 to
If it is within the range of +50 [%], step 330
Then, the process proceeds to step 336 to set the t-time integral component Di (t) as the integral component Di. Then, the integral component Di set in step 332, 334 or 336 and the proportional component Dp set in step 322 are set.
Thus, in step 338, the capacity calculation duty ratio DT is calculated (DT = Dp + Di). Then, in step 340, the integral component Di is calculated for a predetermined time Δ
t is set as a time integral component D (t−Δt) before t,
The process returns to the control routine shown in FIG. Then, at step 350, the capacity calculation duty ratio DT is set as the capacity control duty ratio D, and at step 380, the capacity control duty ratio D is output.

After the displacement control in step 300, the control of the expansion valve 5 is executed in step 400. The control of the expansion valve 5 is, for example, as shown in FIG. 13. First, at step 402, it is determined whether or not the compressor 2 is in operation (COMP ON?). In this determination, if the compressor 2 is not operating (N), the routine proceeds to step 404, where the proportional component Eph_p of the duty ratio of the valve opening control duty ratio EXP output to the electromagnetic coil (not shown) of the expansion valve is provided. Is set to “0”, and in step 406, the integral component Eph_i (t−Δt) before the time Δt is set to “0”, and in step 408, the valve opening control duty ratio E
XP is set to “0”, and from step 500, the valve opening control duty ratio EXP is output to the electromagnetic coil of the expansion valve. In this case, in step 500, the valve opening control duty ratio EXP is not substantially output. Also,
In the valve opening control duty ratio EXP, when the duty ratio is 0 [%], the expansion valve 5 is fully opened and the duty ratio is 10%.
It is fully closed when it is 0 [%].

When it is determined in step 402 that the compressor 2 is operating, in step 410, the target high pressure PHset
Equation (PHset = A * T) shown in block 10
ref + B) is calculated from the refrigerant temperature Tref. Then, in step 412, step 410
It is determined whether or not the target high pressure PHset calculated in is lower than a predetermined pressure P1 (for example, 14 MPa). If the target high pressure PHset is equal to or higher than the predetermined pressure P1 (N),
Proceeding to step 414, the target high pressure PHset is set so that the target high pressure PHset does not exceed the predetermined pressure P1.
A predetermined pressure P1 is set to set as an upper limit pressure. When the target high pressure PHset is equal to or lower than the predetermined pressure P1, the target high pressure PHset calculated by the above formula is used, bypassing the step 414.

In step 420, the valve opening calculation duty ratio Eph is calculated. The calculation of the valve opening calculation duty ratio Eph is, for example, as shown in FIG.
In this calculation flowchart, first, step 422 is executed.
Sets constants used in the calculations in steps 424 and 426. This constant is, for example, a1 is 0.
5, b1 is 0.5 and c1 is 0.05. Then, in step 424, the calculation of the proportional component Eph_p of the valve opening duty ratio is performed based on the characteristic line shown in FIG. 15 based on the temperature difference (Teva-Teva_se) between the evaporator temperature Teva and the evaporator target temperature Teva_set.
It is calculated from t). Note that this characteristic line indicates 0 [%] (fully open) when the temperature difference is -0.5 ° C, and +0. It changes linearly to 100% (fully closed) at 5 ° C.

Further, in step 426, the temperature difference (Teva-Tev) is determined based on the characteristic line shown in FIG.
a_set), the change ΔEph_i of the integral component is calculated. Then, in step 428, the t time integral component Eph_i (t) is calculated according to the results of these calculations in the equation {Eph_i} shown in the block of step 428.
(T) = Eph_i (t−Δt) + ΔEph_i｝ This is because the integral component Eph_
ΔEph calculated in step 426 to i (t−Δt)
_I.

Then, it is determined in step 430 whether or not the t-time integral component Eph_i (t) calculated in step 428 is 50% or more.
At 30, the integral component Eph_i (t) is -50 [%].
It is determined whether or not: In these determinations, if the t-time integral component Eph_i (t) is equal to or more than +50 [%], the process proceeds from step 430 to step 434, where the integral component Eph_i is set to the upper limit 50 [%], If the integral component Eph_i (t) is equal to or smaller than -50 [%], the process proceeds from step 432 to step 436, where the lower limit value -50 [%] is set for the integral integral Eph_i.
And the t time integral component Eph_i (t) is -50.
If it is between +50 [%], the process proceeds from step 432 to step 438 to set the t-time integral component Eph_i (t) as the integral component Eph_i. Then, at step 440, the valve opening calculation duty ratio Eph
To the equation (Eph) shown in the block of step 440.
= Eph_p + Eph_i). Further, in step 442, the integral component Eph_i set in the above step 434, 436 or 438 is Δt
This is set as the integral component Eph_i (t-Δt) before the time, exits from the Eph calculation routine, and returns to the control routine shown in FIG.

After the calculation of the valve opening degree calculation duty ratio Eph, the absolute value of the change rate ΔDT of the capacity calculation duty ratio DT of the compressor 2 calculated in step 300 in step 450 is equal to or smaller than a predetermined value β. It determines whether or not. If it is determined in step 450 that the change rate ΔDT is equal to or smaller than the predetermined value β (Y), the change in the compressor capacity is not large, and thus the change is supplied to the electromagnetic coil of the expansion valve 5 in step 460. The duty ratio of the valve opening control duty ratio EXP is set to Eph, and is output to the expansion valve 5 in step 500. If it is determined in step 450 that the rate of change ΔDT is larger than the predetermined value β (N), it is possible to determine that the capacity change of the compressor 2 is large, so that the high pressure that changes following the capacity change. Latest calculation duty ratio Eph calculated based on pressure
In this case, since there is a possibility that the entire cycle may be changed unnecessarily, step 460 is avoided and the previous valve opening control signal is maintained. As a result, the opening degree of the expansion valve 5 is fixed, so that the pressure fluctuation of the refrigeration cycle 1 due to the change in the capacity of the compressor 2 can be suppressed at an early stage. Also,
In the calculation stage, the valve opening of the expansion valve 5 can be adjusted in accordance with the change in the capacity change of the compressor 2, so that the responsiveness of the expansion valve 5 can be improved.

Hereinafter, other embodiments of the present invention will be described. The same portions and portions having the same effects are denoted by the same reference numerals and description thereof is omitted.

FIG. 17 shows a second embodiment of the present invention. In the second embodiment, if the absolute value of the change rate ΔDT of the displacement control ratio of the compressor 2 in the step 450 is equal to or smaller than the predetermined range β in the determination in the step 450, the valve opening control duty ratio The valve opening calculation duty ratio E is added to EXP.
When ph is set, or when “0” is set to the valve opening control duty ratio EXP in step 408, “0” is set in the flag A (Flag A) in step 464. .

If it is determined in step 450 that the absolute value of the change rate ΔDT is out of the predetermined range β, the flag A is determined in step 452, and if the flag A is “0” (Y). Contains step 45
Proceeding to 4, it is determined whether the change rate ΔDT is positive or negative. If the rate of change ΔDT is positive in the determination of step 454 (N), it can be determined that the capacity has greatly changed in the direction of increasing the capacity. Therefore, the process proceeds to step 458, and the valve opening degree control duty ratio EXP is adjusted to the valve opening degree. Degree calculation duty ratio Ep
A predetermined value R (for example, 20%) is added to h. As a result, a predetermined value R is added to the valve opening calculation duty Eph, which is estimated to be calculated so that the expansion valve 5 is controlled to open. . If the rate of change ΔDT is negative (Y) in the determination in step 454, it can be determined that the capacitance has largely changed in the direction of decreasing the capacity.
6, the valve opening control duty ratio EXP is set to a predetermined value R (for example, 20%) for the valve opening calculation duty ratio Eph.
pull. By this, a predetermined value R is subtracted from the valve opening calculation duty ratio Eph, which is estimated to be calculated so that the expansion valve 5 is controlled in the closing direction, to correct the valve opening in the opening direction. It is. Then, in step 462, the flag A is set to "1", and the valve opening control duty ratio EXP in which the corrected value has been set is set in step 5
Output from 00. When “1” is set in the flag A, if it is determined in step 450 that the change in the change rate ΔDT is large, the process proceeds to step 452.
In step (d), the process proceeds to step 500, so that the corrected valve opening is maintained.

Thus, when the change in the calculation result of the discharge capacity of the compressor 2 is large, the valve opening calculation duty ratio Eph of the expansion valve 5 is set in a direction to suppress the change in the valve opening caused by the change in the compressor discharge capacity. Since the correction is made, the pressure fluctuation of the refrigeration cycle 1 can be stabilized at an early stage.

In the third embodiment shown in FIG. 18, if the rate of change ΔDT of the capacitance calculation duty ratio DT is within a predetermined range after the determination in step 450, the process proceeds to step 451. The numerical values a, b, and c of the characteristic lines shown in FIGS. 15 and 16 are replaced with ordinary values a1, b1, and c.
1 (for example, a1 = 0.5, b1 = 0.5, c1 = 0.
05), and when the rate of change ΔDT is out of the predetermined range, in step 453, the numerical values a, b, and c of the characteristic line are set to a larger than a1, b1, and c1.
2, b2, c2 (for example, a2 = 5, b2 = 2, c2 =
0.5) is set. Accordingly, when the rate of change ΔDT is large, the temperature difference (Te
va-Teva_set), the change rate of the proportional component Eph_p and the integral component Eph_i of the valve opening calculation duty ratio Eph calculated from this temperature difference can be reduced. Thus, the operation of the expansion valve 5 can be suppressed, and the same effects as in the above-described embodiment can be obtained.

In the fourth embodiment shown in FIG. 19, when the absolute value of the rate of change ΔDT is equal to or larger than a predetermined value β, it is determined in step 452 whether or not the flag A is “0”. In step 453, the latest valve opening calculation duty ratio Eph is set as the reference duty ratio Eph0, and if "1" is set in the flag A, Eph0 has already been set. So
Step 453 is bypassed. Then, step 455
It is determined whether or not the valve opening calculation duty ratio Eph is equal to or greater than the reference duty ratio Eph0 + 20 [%]. Further, in step 457, the valve opening calculation duty ratio Eph is equal to or smaller than the reference duty ratio Eph0-20 [%]. Is determined, the valve opening calculation duty ratio E
If ph is larger than the reference duty ratio Eph0 by 20% or more, the process proceeds from step 455 to step 459, where the valve opening duty ratio Eph is limited to Eph0 + 20, and the valve opening calculation duty ratio Eph is changed to the reference duty ratio. If it is smaller than Eph0 by 20% or more, the routine proceeds from step 457 to step 461, where the valve opening duty ratio Eph is limited to Eph0-20. As a result, the valve opening calculation duty ratio Eph limited and set in step 459 or step 461 is set to the valve opening control duty ratio EXP in step 463. Only when the valve opening calculation duty ratio Eph is within the range of the reference duty ratio Eph0 ± 20 [%], in step 463, the valve opening calculation duty ratio Eph is directly used as the valve opening control duty ratio EXP.
Is set to Then, at step 465, "1" is set to the flag A.

With the above configuration, when the change rate ΔDT of the capacity calculation duty ratio DT of the compressor 2 is large, the valve opening calculation duty ratio Eph for determining the valve opening of the expansion valve 5 is changed to the reference duty ratio Eph0. ± 20 [%]
, The fluctuation of the opening of the expansion valve 5 can be suppressed with respect to the fluctuation of the discharge capacity of the compressor 2, and the same effects as those of the above-described embodiment can be obtained. .

Further, in the fifth embodiment shown in FIGS. 20 to 27, in the capacity control routine of the above-described embodiment, the capacity calculation duty ratio DT in step 320 is used.
, The displacement duty ratio D in which the correction duty ratio DT 'is calculated in step 360
This correction duty ratio DT 'is set.

In the calculation of the correction duty ratio DT ', the upper limit value DTLu and the lower limit value DTLd of the duty ratio are calculated in step 362 as shown in FIG.
The upper limit value DTLu and the lower limit value DTLd are calculated from the target blowing temperature Tao based on the characteristic line shown in FIG. Note that this characteristic line indicates that the target outlet temperature Tao is −10 ° C.
Below, the upper limit value DTLu is 100 [%], and the lower limit value D
TLd is 50%, and the target outlet temperature Tao
Is within a predetermined range around 20 ° C., the upper limit value DTL
When u is 75 [%] and the lower limit value DTLd is 25 [%], and when the target blowing temperature Tao is 50 ° C. or higher, the upper limit value DTLu is 50 [%] and the lower limit value DTLd is 0 [%]. Is set to

In step 364, it is determined whether or not the capacity calculation duty ratio DT is equal to or more than the upper limit value DTLu set in step 362.
In step 66, the capacity calculation duty ratio DT is
It is determined whether or not it is equal to or less than the lower limit value DTLd set in 62. In this determination, the capacity calculation duty ratio D
If T is greater than or equal to the upper limit value DTLu, step 36
4 to step 368 to proceed to the correction duty ratio DT '.
When the capacity calculation duty ratio DT is equal to or smaller than the lower limit value DTLd, the process proceeds from step 366 to step 370, where the lower limit value DTLd is set as the correction duty ratio DT ', and The calculation duty DT has an upper limit value DTLu and a lower limit value DTL
If it is between d, the routine proceeds to step 372, where the capacity calculation duty ratio DT is set as the correction duty ratio DT '. Then, in step 372, the correction duty ratio DT 'is set to the capacity control duty ratio D, and output in step 380.

Further, the upper limit value DTLu and the lower limit value DT
In the calculation of Ld, the calculation may be performed based on the temperature difference between the actual temperature Teva of the evaporator 6 and the target temperature Teva_set of the evaporator 6, as shown in FIG. In this characteristic line,
When the temperature difference is −20 ° C., the upper limit value DTLu is 50.
[%], The lower limit value DTLd is 0 [%], and when the temperature difference is within a predetermined range around 0 ° C., the upper limit value DTLu is 75 [%], and the lower limit value DTLd is 25 [%]. When the temperature difference is 20 ° C. or more, the upper limit value DTLu is 1
00 [%] and the lower limit value DTLd is set to 50 [%].

The control of the electric expansion valve according to the fifth embodiment is as shown in FIG.
After calculating the valve opening degree calculation duty ratio Eph by 0, in step 470, the valve opening degree correction duty ratio Eph 'is set.
Is calculated. This valve opening correction duty ratio E
The operation of ph 'is as shown in FIG.
, The upper limit value Ep of the valve opening calculation duty ratio Eph
hu and the lower limit Ephd are calculated. This upper limit value Ep
When the correction duty ratio of the capacity control is calculated based on the target blowout temperature Tao, the hu and the lower limit value Ephd are calculated from the same target blowout temperature Tao based on the characteristic line shown in FIG. In addition, this characteristic line shows that the upper limit value Ephu is 10 when the target blowout temperature Tao is −10 ° C. or less.
0%, the lower limit value Ephd is 50%, and when the target outlet temperature Tao is within a predetermined range of about 20 ° C., the upper limit value Ephu is 75%, and the lower limit value Ep is 75%.
When the target blowing temperature Tao is 50 ° C. or higher, the upper limit Ephu is set to 50% and the lower limit Ephd is set to 0%.

In step 474, it is determined whether or not the valve opening calculation duty ratio Eph is equal to or larger than the upper limit value Ephu set in step 472. In step 476, the valve opening calculation duty ratio Eph is determined. It is determined whether the value is equal to or less than the lower limit value Ephd set in step 472. In this determination, if the valve opening calculation duty ratio Eph is equal to or greater than the upper limit value Ephu,
Proceeding from step 474 to step 478, the upper limit Eph is set as the valve opening correction duty ratio Eph ', and the valve opening calculation duty ratio Eph is set to the lower limit Ephd.
If not, then steps 476 to 48
The process proceeds to 0, the lower limit value Ephd is set as the valve opening correction duty ratio Eph ', and if the valve opening calculation duty Eph is between the upper limit value Ephu and the lower limit value Ephd, the process proceeds to step 482. The valve opening calculation duty ratio Eph is set as a valve opening correction duty ratio Eph '. Then, in step 484, the valve opening control duty ratio Eph 'is added to the valve opening control duty ratio EXP.
Is set and output in step 500.

The upper limit value Ephu and the lower limit value Ep are described below.
hd, the correction duty ratio DT ′ is
Actual temperature Teva of evaporator 6 and evaporator 6
Is calculated based on the temperature difference between the target temperature Teva_set and the target temperature Teva_set, as shown in FIG.
hu and the lower limit value Ephd are calculated based on the actual temperature Teva of the evaporator 6 and the target temperature Teva_ of the evaporator 6.
The calculation is performed based on the temperature difference between the set and the set.
In this characteristic line, when the temperature difference is −20 ° C., the upper limit Ephu is 50% and the lower limit Ephd is 0%.
When the temperature difference is within a predetermined range around 0 ° C., the upper limit Ephu is 75%, the lower limit Ephd is 25%, and when the temperature difference is 20 ° C. or more, The upper limit Ephu is set to 100 [%], and the lower limit Ephd is set to 50 [%].

With the above arrangement, the valve opening degree correction duty ratio Eph 'of the valve opening degree calculation duty ratio Eph is calculated based on the same factors as those for calculating the discharge capacity (correction duty ratio DT') of the compressor 2. As a result, the opening degree of the expansion valve 5 can be controlled in accordance with the change in the discharge capacity of the compressor 2, and the pressure fluctuation of the refrigeration cycle 1 based on the change in the discharge capacity of the compressor 2 can be stabilized early. Something that can be done. In addition, a response delay of the expansion valve 5 can be avoided.

Further, in the calculation of the valve opening duty ratio Eph of the expansion valve 5 according to the sixth embodiment shown in FIGS. 28 to 30, for example, step 450 is omitted in the electric expansion valve control flowchart shown in FIG. The flow chart is a part of the flowchart shown in the flowchart, and is a calculation in which the operation of the valve opening of the expansion valve 5 is suppressed in the calculation of the valve opening duty ratio Eph. In this operation flowchart, first, in step 423, operation constants a, b,
Numerical values a1, b2, c1, and e1 are set in c and e. These numerical values are, for example, a1 is 0.5, b1 is 0.5,
c1 is 0.05 and e1 is 0.02.

Then, in step 425, a proportional component calculation X factor X_p for calculating the proportional component Eph_p of the valve opening calculation duty ratio Eph is calculated from the target high pressure PHset of the high pressure line and the actual pressure PH.
Equation {X_p = PHset} shown in 25 blocks
− (PH−e * D)}. In this equation, when the capacity control duty ratio D of the compressor 2 increases, the actual pressure PH increases, but the e * D component is subtracted from the actual pressure.
The change of the factor X_p is suppressed. Then, the proportional component Eph_p of the valve opening calculation duty ratio is calculated from the characteristic line shown in FIG. 28 based on the proportional component calculation X component X_p. At this time, since the change in the proportional component calculation X component X_p is suppressed, the change in the proportional component Eph_p of the valve opening calculation duty ratio Eph is also suppressed.

Then, in step 429, it is determined whether or not the time differential value dD / dt of the capacity control duty ratio D is 0 or more. If dD / dt is 0 or more, the flow proceeds to step 431. The calculation of the X component X_i for the integration component calculation is performed by the formula ｛X_i = (PHset−PH) / (dD / dt) shown in the block of step 431.
+1)}, and when dD / dt is smaller than 0, the process proceeds to step 433 to calculate the X component X_i for the integral component calculation by using the formula {X_i = (PHset− PH) / (1-dD
/ Dt)}. Then, based on the characteristic line shown in FIG. 29, the integration component Ep of the valve opening degree calculation duty ratio Eph is calculated by the integration component calculation X component X_i.
A change ΔEph_i of h_i is calculated. In step 437, the valve opening calculation duty ratio Eph
Is calculated, and thereafter the valve opening degree calculation duty ratio Eph_i (t) is calculated as in the above-described embodiment.
ph is calculated.

As a result, steps 431 and 433
In the equation shown in the following, the capacity control duty ratio D
Becomes smaller, the dD / dt approaches 0. Therefore, the X component X_i for the integral component calculation approaches the value of Phset-PH, and the change ΔEph of the equivalent component of the related art is obtained.
_I can be calculated. Also, if the change in the capacity control duty ratio D increases, dD / dt increases, so that the denominator of the equation increases and the change ΔEph_i
Becomes smaller, and the sensitivity can be made lower than before.

Thus, the capacity control duty ratio D
Is used as a calculation factor of the valve opening calculation duty ratio Eph, and when the change of the capacity control duty ratio D is large, the proportional component Ep of the calculated valve opening calculation duty ratio is calculated.
Since the calculation amount of h_p and the integral component Eph_i is limited, a rapid change in the valve opening of the expansion valve 5 due to a rapid change in the discharge capacity of the compressor 2 can be suppressed. Can be stabilized early. Further, since the change in the capacity of the compressor 2 can be taken into account at the time of calculating the valve opening of the expansion valve 5, the responsiveness of the expansion valve 5 can be improved.

[0064]

As described above, according to the present invention, the discharge capacity of the compressor or a change in the discharge capacity is determined in the calculation stage, and this is taken into account when calculating the valve opening of the electric expansion valve. Therefore, a delay in the response of the expansion valve can be avoided, and the pressure fluctuation in the refrigeration cycle can be stabilized early. Further, since the expansion valve control can be performed in consideration of the change in the discharge capacity of the compressor before the pressure change, more appropriate control can be performed, and the stable performance of the refrigeration cycle can be maintained. Further, according to the present invention, it is not necessary to provide a pressure sensor for detecting the suction pressure, so that an increase in the cost of the system can be avoided.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a first configuration of the present invention.

FIG. 2 is a functional block diagram showing a second configuration of the present invention.

FIG. 3 is a functional block diagram showing a third configuration of the present invention.

FIG. 4 is a functional block diagram showing a fourth configuration of the present invention.

FIG. 5 is a schematic configuration diagram showing a configuration of a refrigeration cycle according to the present invention.

FIG. 6 is a flowchart illustrating a main control routine of refrigeration cycle control according to the embodiment of the present invention.

FIG. 7 is a flowchart illustrating a target outlet temperature calculation routine according to the embodiment of the present invention.

FIG. 8 is a flowchart illustrating an electromagnetic clutch control routine according to the embodiment of the present invention.

FIG. 9 is a flowchart illustrating a compressor capacity control routine according to the embodiment of the present invention.

FIG. 10 is a flowchart showing a calculation routine of a capacity calculation duty ratio DT in a capacity control routine of the compressor according to the embodiment of the present invention.

FIG. 11 is a characteristic line showing a characteristic line for calculating a proportional component Dp of a duty ratio from a temperature difference between an actual temperature of an evaporator and a target temperature in a calculation routine of a capacitance operation duty ratio DT according to the embodiment of the present invention. FIG.

FIG. 12 shows a characteristic line for calculating a variation ΔDi of an integral component of a duty ratio from a temperature difference between an actual temperature of an evaporator and a target temperature in a calculation routine of a capacitance calculation duty ratio DT according to the embodiment of the present invention. FIG.

FIG. 13 is a flowchart illustrating an electric expansion valve control routine according to the first embodiment of the present invention.

FIG. 14 is a valve opening calculation duty ratio Ep in the electric expansion valve control routine according to the first embodiment of the present invention;
FIG. 9 is a flowchart illustrating an h calculation routine.

FIG. 15 is a characteristic line for calculating a proportional component Eph_p of a duty ratio from a temperature difference between an actual temperature of an evaporator and a target temperature in a calculation routine of a valve opening calculation duty ratio Eph according to the first embodiment of the present invention. FIG.

FIG. 16 is a diagram illustrating a calculation routine of a valve opening calculation duty ratio Eph according to the first embodiment of the present invention, which calculates a change ΔEph_i of an integral component of a duty ratio from a temperature difference between an actual temperature of an evaporator and a target temperature. FIG. 4 is a characteristic diagram showing characteristic lines of the present invention.

FIG. 17 is a flowchart illustrating only a characteristic part of the second embodiment in a calculation routine of the valve opening calculation duty ratio Eph according to the second embodiment of the present invention.

FIG. 18 is a flowchart showing only a characteristic part of the third embodiment in a calculation routine of the valve opening calculation duty ratio Eph according to the third embodiment of the present invention.

FIG. 19 is a flowchart showing only a characteristic portion of the fourth embodiment in a calculation routine of the valve opening calculation duty ratio Eph according to the fourth embodiment of the present invention.

FIG. 20 is a flowchart showing a capacity control routine according to a fifth embodiment of the present invention.

FIG. 21 is a flowchart illustrating a calculation routine of a capacity correction duty ratio DT ′ in a capacity control routine according to a fifth embodiment of the present invention.

FIG. 22 is a characteristic diagram for obtaining an upper limit value and a lower limit value from a target outlet temperature Tao in a calculation routine of a capacity correction duty ratio DT ′ according to the fifth embodiment of the present invention.

FIG. 23 is a characteristic diagram for obtaining an upper limit value and a lower limit value from a temperature difference between an actual temperature of an evaporator and a target temperature in a calculation routine of a capacity correction duty ratio DT ′ according to the fifth embodiment of the present invention. .

FIG. 24 is a flowchart showing an electric expansion valve control routine according to a fifth embodiment of the present invention.

FIG. 25 is a valve opening correction duty ratio Ep in an electric expansion valve control routine according to a fifth embodiment of the present invention;
FIG. 14 is a flowchart illustrating a calculation routine of h ′.

FIG. 26 is a characteristic diagram for obtaining an upper limit value and a lower limit value of the valve opening duty ratio Eph from the target outlet temperature Tao in the calculation routine of the valve opening correction duty ratio Eph ′ according to the fifth embodiment of the present invention. It is.

FIG. 27 is a diagram illustrating a calculation routine of a valve opening correction duty ratio Eph ′ according to a fifth embodiment of the present invention, based on a temperature difference between an actual temperature of an evaporator and a target temperature; It is a characteristic diagram which calculates | requires a lower limit.

FIG. 28 is a flowchart illustrating a calculation routine of a valve opening calculation duty ratio Eph according to the sixth embodiment of the present invention.

FIG. 29 is a characteristic diagram showing a characteristic line for calculating a proportional component Eph_p of a valve opening calculation duty ratio Eph according to a sixth embodiment of the present invention from a factor X_p in consideration of a compressor capacity control duty ratio. It is.

FIG. 30 shows a change ΔEph_i of the integral component of the valve opening calculation duty ratio Eph according to the sixth embodiment of the present invention.
Is a characteristic diagram showing a characteristic line calculated from a factor X_i in consideration of a capacity control duty ratio of a compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigeration cycle 2 Compressor 3 Radiator 4 Internal heat exchanger 5 Electric expansion valve 6 Evaporator 8 Electromagnetic clutch 9 Variable capacity mechanism 10 Control unit 11 High pressure line 12 Low pressure line

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Kunio Mizuno Inventor F-term (reference) 3L060 AA02 CC02 CC04 CC16 DD02 EE02 EE09, 39, Higashihara, Chiyo-ji, Odai-gun, Osato-gun, Saitama

Claims (14)

[Claims] 1. A compressor whose discharge capacity is changed by a control signal from the outside, a radiator for cooling high-pressure refrigerant discharged from the compressor, and a pressure of the refrigerant cooled by the radiator is reduced. In a refrigeration cycle at least comprising an expansion means whose valve opening is varied by an external control signal and an evaporator for evaporating a low-pressure refrigerant flowing out of the expansion means, the discharge capacity of the compressor is changed. At least a compressor capacity control means, and a valve opening control means for controlling a valve opening degree of the expansion means, wherein a control signal to the valve opening control means is a control signal outputted to the compressor capacity control means. A refrigeration cycle control device that is corrected based on the following. 2. An air temperature setting means for setting a target temperature of the air passing through the evaporator; an air temperature detecting means for detecting a temperature of the air passing through the evaporator; and the expansion from a discharge side of the compressor. Refrigerant temperature detecting means for detecting the refrigerant temperature of the high pressure line reaching the inflow side of the means; high pressure pressure detecting means for detecting the pressure of the high pressure line; target temperature and air temperature detection set by the air temperature setting means Means for calculating the discharge capacity of the compressor based on the actual temperature detected by the means; and compressor capacity for outputting a control signal to the compressor based on the discharge capacity calculated by the discharge capacity calculation means. Control means for calculating a target high pressure based on the refrigerant temperature detected by the refrigerant temperature detecting means. Calculating means, based on the actual high pressure detected by the high pressure detecting means and the target high pressure calculated by the target high pressure calculating means, a valve opening calculating means for calculating the valve opening of the expansion means, A discharge capacity determining means for determining a state of the discharge capacity calculated by the discharge capacity calculating means; and a valve opening degree calculating means when the state of the discharge capacity detected by the discharge capacity determining means matches a predetermined condition. Valve opening correction means for correcting the valve opening calculated by the above, and valve opening control means for outputting a control signal to the expansion means based on the valve opening corrected by the valve opening correction means. The refrigeration cycle control device according to claim 1, wherein: 3. The discharge capacity determination means determines whether or not the change in the discharge capacity calculated by the discharge capacity calculation means is within a predetermined range. When the determination means determines that the change in the discharge capacity is within a predetermined range, the valve opening calculated by the valve opening calculation means is output to the valve opening control means, and the discharge capacity determination is performed. 3. The refrigeration cycle according to claim 2, wherein the valve opening calculated by the valve opening calculating means is invalidated when the change in the discharge capacity is determined to be out of the predetermined range by the means. Control device. 4. The discharge capacity determination means determines whether a change in the discharge capacity calculated by the discharge capacity calculation means is within a predetermined range. When the determination means determines that the change in the discharge capacity is within a predetermined range, the valve opening calculated by the valve opening calculation means is output to the valve opening control means, and the discharge capacity determination is performed. If it is determined by the means that the change in the discharge capacity is outside the predetermined range in the direction of increasing, the valve opening calculated by the valve opening calculating means is corrected to open at a predetermined ratio, and Output to the valve opening control means, and when the discharge capacity determination means determines that the change in the discharge capacity is outside a predetermined range in a decreasing direction, the valve opening calculated by the valve opening calculation means is output. Those who close the degree at a predetermined rate Refrigeration cycle control unit according to claim 2, wherein the correction and output to the valve opening control means. 5. An air temperature setting means for setting a target temperature of the air passing through the evaporator, an air temperature detecting means for detecting a temperature of the air passing through the evaporator, and the expansion from a discharge side of the compressor. Refrigerant temperature detecting means for detecting the refrigerant temperature of the high pressure line reaching the inflow side of the means; high pressure pressure detecting means for detecting the pressure of the high pressure line; target temperature and air temperature detection set by the air temperature setting means Means for calculating a target discharge capacity of the compressor based on the actual temperature detected by the means; and outputting a control signal to the compressor based on the target discharge capacity calculated by the discharge capacity calculation means. A compressor capacity control means, and an object for calculating a target high pressure based on the refrigerant temperature detected by the refrigerant temperature detection means. A reference high pressure calculating means, based on the actual high pressure detected by the high pressure detecting means, the target high pressure calculated by the target high pressure calculating means, and taking into consideration the compressor discharge capacity calculated by the discharge capacity calculating means. A valve opening calculating means for calculating a valve opening of the expansion means; a throttle opening control means for outputting a control signal to the expansion means based on the valve opening calculated by the valve opening calculating means; The refrigeration cycle control device according to claim 1, further comprising: 6. A compressor whose discharge capacity is changed by a control signal from the outside, a radiator for cooling high-pressure refrigerant discharged from the compressor, and a pressure of the refrigerant cooled by the radiator, In a refrigeration cycle at least comprising an expansion means whose valve opening is varied by an external control signal and an evaporator for evaporating a low-pressure refrigerant flowing out of the expansion means, the discharge capacity of the compressor is changed. Compressor capacity control means, and at least valve opening control means for controlling the valve opening degree of the expansion means, wherein a control signal to the valve opening control means is based on a calculation factor of the compressor capacity calculation means. A refrigeration cycle control device characterized by being regulated. 7. An air temperature setting means for setting a target temperature of air passing through the evaporator; an air temperature detecting means for detecting a temperature of air passing through the evaporator; and an air temperature setting means. Temperature difference calculating means for calculating a temperature difference between the target temperature and the actual air temperature detected by the air temperature detecting means; and a target temperature set by the air temperature setting means and detected by the air temperature detecting means. Discharge capacity calculating means for calculating the discharge capacity of the compressor based on the actual temperature, and regulating the discharge capacity calculated by the discharge capacity calculating means based on the temperature difference calculated by the temperature difference calculating means. Discharge capacity regulating means, and a controller for outputting a control signal to the compressor based on the discharge capacity regulated by the discharge capacity regulating means. Claim, characterized by comprising a suppressor capacity control means 6
A refrigeration cycle control device according to the above. 8. An air temperature setting means for setting a target temperature of air passing through the evaporator, an air temperature detecting means for detecting a temperature of air passing through the evaporator, and an air temperature setting means. Temperature difference calculating means for calculating a temperature difference between the target temperature and the actual air temperature detected by the air temperature detecting means, and a refrigerant temperature of a high pressure line from a discharge side of the compressor to an inflow side of the expansion means. Refrigerant temperature detecting means for detecting, high pressure detecting means for detecting the pressure of the high pressure line, target high pressure calculating means for calculating a target high pressure based on the refrigerant temperature detected by the refrigerant temperature detecting means, Based on the actual high pressure detected by the pressure detection means and the target high pressure calculated by the target high pressure calculation means, the valve opening of the expansion means is determined. Valve opening calculating means for calculating; valve opening regulating means for regulating the valve opening calculated by the valve opening calculating means based on the temperature difference calculated by the temperature difference calculating means; 7. The refrigeration cycle control device according to claim 5, further comprising a valve opening control unit that outputs a control signal to the expansion unit based on the valve opening regulated by the degree regulating unit. 9. The discharge capacity control means calculates the discharge capacity calculated by the discharge capacity calculation means based on an upper limit value and a lower limit value set corresponding to the temperature difference calculated by the temperature difference calculation means. Is greater than or equal to the upper limit value, the upper limit value is output to the compressor displacement control means as a discharge displacement, and if the discharge displacement calculated by the discharge displacement calculation means is less than or equal to the lower limit value, the lower limit is set. 9. The refrigeration cycle control device according to claim 7, wherein a value is output to the compressor displacement control means as a discharge displacement. 10. The valve opening control means calculates the valve opening degree based on an upper limit value and a lower limit value set corresponding to the temperature difference calculated by the temperature difference calculating means. When the valve opening is equal to or greater than the upper limit, the upper limit is output as the valve opening to the valve opening controller, and the valve opening calculated by the valve opening calculator is equal to or less than the lower limit. 9. The refrigeration cycle control device according to claim 7, wherein in the case of (1), the lower limit value is output to the valve opening control means as a valve opening. 11. A target blow-out temperature calculating means for calculating a target blow-out temperature based on an environmental load signal, and a target blow-out temperature calculated by the target blow-out temperature calculating means to calculate a target temperature of air blown from the evaporator. Target air temperature calculating means; air temperature detecting means for detecting the temperature of air passing through the evaporator; target air temperature calculated by the target air temperature calculating means and actual air temperature detected by the air temperature detecting means. A discharge capacity calculating means for calculating a discharge capacity of the compressor based on the temperature; and a discharge capacity calculated by the discharge capacity calculating means based on a target blow temperature calculated by the target blow temperature calculating means. Discharge capacity regulating means; and a control signal to the compressor based on the discharge capacity regulated by the discharge capacity regulating means. Claim 6, characterized in that it comprises a compressor capacity control means for outputting a
A refrigeration cycle control device according to the above. 12. A target blow-out temperature calculating means for calculating a target blow-out temperature based on an environmental load signal, and a target temperature of the air blown from the evaporator is calculated from the target blow-out temperature calculated by the target blow-out temperature calculating means. Target air temperature calculating means; air temperature detecting means for detecting the temperature of air passing through the evaporator; refrigerant temperature detecting means for detecting a refrigerant temperature in a high pressure line from a discharge side of the compressor to an inflow side of the expansion means. Means, high-pressure detection means for detecting the pressure of the high-pressure line, target high-pressure calculation means for calculating a target high-pressure based on the refrigerant temperature detected by the refrigerant temperature detection means, detection by the high-pressure detection means The valve opening of the expansion means is calculated based on the actual high pressure thus calculated and the target high pressure calculated by the target high pressure calculation means. Valve opening calculating means, and valve opening restricting means for restricting the valve opening calculated by the valve opening calculating means to a predetermined value based on the target outlet temperature calculated by the target outlet temperature calculating means. The refrigeration cycle according to claim 6, further comprising: a valve opening control unit that outputs a control signal to the expansion unit based on the valve opening regulated by the valve opening regulating unit. Control device. 13. The discharge capacity control means calculates the discharge capacity calculated by the discharge capacity calculation means based on an upper limit value and a lower limit value set in accordance with the target blow temperature calculated by the target blow temperature means. If the displacement is equal to or greater than the upper limit, the upper limit is output to the compressor displacement control means as a discharge displacement, and if the discharge displacement calculated by the discharge displacement calculator is equal to or less than the lower limit, the discharge capacity is calculated. 12. The compressor according to claim 11, wherein a lower limit value is output to said compressor capacity control means as a discharge capacity.
3. The refrigeration cycle control device according to 2. 14. The valve opening degree calculating means calculates the valve opening degree based on an upper limit value and a lower limit value set in accordance with the target blowout temperature calculated by the target blowout temperature calculating means. If the determined valve opening is equal to or greater than the upper limit, the upper limit is output to the valve opening controller as the valve opening, and the valve opening calculated by the valve opening calculator is the lower limit. 13. The refrigeration cycle control device according to claim 11, wherein when the value is equal to or less than the value, the lower limit value is output to the valve opening control means as a valve opening.