JP2002139259A - Refrigerating cycle controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerating cycle controller which can suppress and prevent the unnecessary ripple of a freezing cycle caused by the change of the discharge capacity of a compressor. SOLUTION: This refrigerating cycle controller is so arranged as to compensate the discharge capacity of a compressor calculated by discharge capacity calculation means so that it may not change suddenly, in case that the change of the opening of a valve is judged to have amounted to specified one or over, so this refrigerating cycle controller can suppress the sudden fluctuation of high pressure.

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]

Generally, 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 refrigerating capacity, the radiator needs to be cooled. The refrigerant pressure on the outlet side decreases. 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. In the refrigeration cycle, at least the pressure of the cooled refrigerant is reduced, and the opening degree of the valve is varied by an external control signal, and the evaporator evaporates the low-pressure refrigerant flowing out of the expansion means. A compressor displacement control means for changing a discharge displacement of the compressor, and a valve opening control means for controlling a valve opening of the expansion means, wherein a control signal to the compressor displacement control means The correction is performed based on a control signal output to the degree control means.

[0007] The refrigeration cycle control device is shown in FIG.
As shown in the figure, high-pressure pressure detection means 14 for detecting the pressure of the high-pressure line, refrigerant temperature detection means 13 for detecting the refrigerant temperature of the high-pressure line from the discharge side of the compressor to the inflow side of the expansion means, Refrigerant temperature detecting means 13
And a target high pressure calculated by the high pressure detection means 14 and the target high pressure calculated by the target high pressure calculation means 50. A valve opening calculating means for calculating a valve opening of the expansion means based on the valve opening, and a valve for outputting a control signal to the expansion means based on the valve opening calculated by the valve opening calculating means. Opening degree control means 54, air temperature detection means 15 for detecting the temperature of the air passing through the evaporator, air temperature setting means 30 for setting a target temperature of the air passing through the evaporator,
A discharge capacity calculating means for calculating a discharge capacity of the compressor based on a target temperature set by the air temperature setting means and an actual temperature detected by the air temperature detecting means; and a valve opening calculating means. A valve opening degree judging means 58 for judging the state of the valve opening degree calculated by the valve 52; and a discharge capacity calculation when the state of the valve opening degree judged by the valve opening degree judging means 58 meets a predetermined condition. A discharge capacity correction means 66 for correcting the discharge capacity calculated by the means 56; and a compressor capacity control means 68 for outputting a control signal to the compressor 2 based on the discharge capacity corrected by the discharge capacity correction means 66. Is what you do.

The discharge capacity correction means 66 limits the discharge capacity calculated by the discharge capacity calculation means 56 when the change in the valve opening is equal to or more than a predetermined value.

Further, as shown in FIG. 2, the refrigeration cycle control device includes a high-pressure pressure detecting means 14 for detecting the pressure of the high-pressure line, Refrigerant temperature detecting means 13 for detecting the refrigerant temperature of the high-pressure line, target high-pressure calculating means 50 for calculating a target high-pressure based on the refrigerant temperature detected by the refrigerant temperature detecting means 13, and high-pressure pressure detecting means 14 Valve opening calculating means 52 for calculating the valve opening of the expansion means 5 based on the detected actual high pressure and the target high pressure calculated by the target high pressure calculating means 50; A valve opening control means 54 for outputting a control signal to the expansion means 5 based on the valve opening calculated by the above, and an air for detecting the temperature of the air passing through the evaporator. A temperature detection means 15, the air temperature setting means 3 for setting a target temperature of air passing through the evaporator
0, a discharge capacity calculating means 56 for calculating the discharge capacity of the compressor 2 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; The high-pressure fluctuation determining means 60 for detecting the fluctuation of the high-pressure detected by the high-pressure detecting means 14, and the discharge displacement calculating means 56 when the high-pressure fluctuation matches the predetermined condition by the high-pressure fluctuation determining means 60. Discharge capacity correction means 66 for correcting the calculated discharge capacity, and compressor capacity control means 6 for outputting a control signal to the compressor 2 based on the discharge capacity corrected by the discharge capacity correction means.
8 is provided.

When the high pressure fluctuation determining means 60 determines that the pressure fluctuation is equal to or greater than a predetermined value, the discharge capacity correcting means 66 outputs the discharge capacity calculating means 56.
This limits the discharge capacity calculated by the above.

Further, as shown in FIG. 3, the refrigeration cycle control device includes a high-pressure pressure detecting means 14 for detecting a pressure of the high-pressure line, and a high-pressure Refrigerant temperature detecting means 13 for detecting the refrigerant temperature of the line, target high pressure calculating means 50 for calculating a target high pressure based on the refrigerant temperature detected by the refrigerant temperature detecting means 13, and detection by the high pressure detecting means 14. The valve opening degree calculating means 52 for calculating the valve opening degree of the expansion means 5 based on the actual high pressure thus obtained and the target high pressure calculated by the target high pressure calculating means 50, and the valve opening degree calculating means 52 A valve opening control means 54 for outputting a control signal to the expansion means 5 based on the calculated valve opening, and a valve for detecting the temperature of air passing through the evaporator. Temperature detection means 15; air temperature setting means 30 for setting a target temperature of the air passing through the evaporator; target temperature set by the air temperature setting means 30 and the actual temperature detected by the air temperature detection means 15. A discharge capacity calculating means 56 for calculating a discharge capacity of the compressor 2 based on the temperature of the compressor 2, and a pressure between the high pressure detected by the high pressure detecting means 14 and the target high pressure calculated by the target high pressure calculating means 50. A pressure difference calculating means 62 for calculating the difference;
Pressure difference determining means 64 for determining whether or not the pressure difference calculated by step 2 matches a predetermined condition; and discharging when the pressure difference determining means 64 determines that the pressure difference matches a predetermined condition. A discharge capacity correction means 66 for correcting the discharge capacity calculated by the capacity calculation means 56; a compressor capacity control means 58 for outputting a control signal to the compressor 2 based on the discharge capacity corrected by the discharge capacity correction means 66; Is provided.

The discharge capacity correction means 66 limits the discharge capacity calculated by the discharge capacity calculation means 56 when the pressure difference determination means 64 determines that the pressure difference is equal to or greater than a predetermined value. It is in.

Further, the above-mentioned limitation of the discharge capacity is to hold the previously calculated discharge capacity, to fix the discharge capacity for a predetermined time, and to limit the upper and lower limits of the discharge capacity. is there.

Thus, according to the present invention, when it is determined that the change in the valve opening is equal to or greater than a predetermined value, the compressor displacement calculated by the displacement calculator is corrected so as not to change abruptly. As a result, it is possible to suppress a rapid change in the high pressure and to achieve appropriate refrigeration cycle control.

Further, in the invention shown in FIG. 4, the high pressure pressure detecting means 14 for detecting the pressure of the high pressure line and the refrigerant temperature of the high pressure line from the discharge side of the compressor 2 to the inflow side of the expansion means 5 are detected. Refrigerant temperature detecting means 13 for detecting, target high pressure calculating means 50 for calculating a target high pressure based on the refrigerant temperature detected by the refrigerant temperature detecting means 13, and actual high pressure detected by the high pressure detecting means 14 Based on the pressure and the target high pressure calculated by the target high pressure calculation means 50, the expansion means 5
A valve opening degree calculating means 52 for calculating the valve opening degree, a valve opening degree controlling means 54 for outputting a control signal to the expansion means 5 based on the valve opening degree calculated by the valve opening degree calculating means 52,
Air temperature detecting means 15 for detecting the temperature of the air passing through the evaporator, air temperature setting means 30 for setting a target temperature of the air passing through the evaporator, and a target set by the air temperature setting means 30. A discharge capacity calculating means 56 'for calculating the discharge capacity of the compressor 2 based on the temperature, the actual temperature detected by the air temperature detecting means 15 and the valve opening calculated by the valve opening calculating means 52; The compressor displacement control means 68 which outputs a control signal to the compressor 2 based on the displacement corrected by the displacement calculation means 56 '.

Further, the discharge capacity calculation means calculates the discharge capacity of the compressor based on the target temperature set by the air temperature setting means and the actual temperature detected by the air temperature detection means. It is desirable that the displacement of the compressor be corrected using the valve opening calculated by the valve opening calculating means as a factor.

[0017]

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 the refrigerant, and has a variable displacement mechanism 9 for varying the discharge capacity based on the pressure on the low pressure side, and a traveling system (not shown). 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. A path from the discharge side of the compressor 2 to the inflow side of the electric expansion valve 5 forms a high-pressure line 11.

At 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 A temperature setting signal (Tptc) from a temperature setting switch 20 from the operation panel 19; And at least a setting signal (Teva_set) from the volume switch 30 for setting the evaporator temperature, etc., and are processed and controlled by a predetermined program as shown in the flowchart below. The signals are output to the electromagnetic clutch 8, the variable capacity mechanism 9, the expansion valve 5, and the like.

The control executed by the control unit 10 according to the embodiment of the present invention will be described below with reference to each flowchart.

FIG. 6 shows a basic flowchart of the refrigeration cycle control. This flowchart is started periodically from step 100, for example, from the main control routine of air conditioning control. In step 110, initialization of various signals can be performed.
At 0, a signal processing operation is performed. This step 12
0, each sensor 13, 14, 1
The signals from 5, 16, 17, 18 and the setting signal from the operation panel 19 are read and processed into operation signals which can be operated.
, The target outlet temperature (Tao) is calculated. The calculation of the target outlet temperature Tao is performed by using, for example, a mathematical expression shown in step 124. This step 12
4, T'ptc is a temperature setting signal calculated from the temperature setting signal Tptc from the temperature setting switch 20, and Q'sun is the amount of solar radiation calculated from the solar radiation signal Qsun from the solar radiation sensor 18. Signal
A, B, C, and D are operation constants for weighting 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? ), 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. 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 equal to or less than 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 expansion valve 5 is executed in step 300. The control of the expansion valve 5 is, for example, as shown in FIG. 9. First, at step 302, it is determined whether or not the compressor 2 is operating (COMP ON?). In this determination, if the compressor 2 is not operating (N), the routine proceeds to step 304, 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 306, the integral component Eph_i (t−Δt) before the time Δt is set to “0”. In step 308, the valve opening degree control duty ratio E
XP is set to “0”, and the valve opening control duty ratio EXP is output to the electromagnetic coil of the expansion valve 5 from step 350. In this case, the valve opening control duty ratio EXP is output as "0" in step 350, but substantially no signal is output. In the valve opening control duty ratio EXP, the duty ratio is 0 [%].
, The expansion valve 5 is fully opened, and when the duty ratio is 100 [%], it is fully closed.

If it is determined in step 302 that the compressor 2 is operating, then in step 310 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 312, step 310
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 314, 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 314.

In step 316, a 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 318
Sets constants used in the calculations in step 320 and step 322. This constant is, for example, if D1 is 0.
5, E1 is 0.5 and F1 is 0.05. In step 320, the proportional component Eph_p of the valve opening duty ratio is calculated from the pressure difference (PHset-PH) between the target high pressure PHset and the high pressure PH based on the characteristic line shown in FIG. Is done. 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 322, FIG.
Based on the characteristic line shown in FIG.
et-PH), the variation ΔEph_i of the integral component is calculated. Then, at step 324, the t time integral component Eph_i (t) is expressed by the mathematical expression {Eph_i} shown in the block of step 324 according to these calculation results.
(T) = Eph_i (t−Δt) + ΔEph_i｝ This is because the integral component Eph_
ΔEph calculated in step 322 to i (t−Δt)
_I.

Then, at step 326, it is determined whether or not the t-time integral component Eph_i (t) calculated at step 324 is 50% or more.
At 28, 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 326 to step 330, where the integral component Eph_i is set to the upper limit value 50 [%]. If the integral component Eph_i (t) is equal to or smaller than -50 [%], the process proceeds from step 328 to step 332, 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 328 to step 334 to set the t-time integral component EphI (t) as the integral component Eph_i. And
At step 336, the valve opening calculation duty ratio Eph is calculated by the equation (Eph = E) shown in the block of step 336.
ph_p + Eph_i), and in step 338, the above-mentioned step 330, 332 or 3
The integral component Eph_i set at 34 is set as the integral component Eph_i (t−Δt) before the time Δt, and the process exits 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 duty ratio of the valve opening degree control duty ratio EXP supplied to the electromagnetic coil of the expansion valve 5 is set to Eph in step 340, and the expansion ratio is set in step 350. This is output to the valve 5.

After the valve opening control in step 300, in step 400, the displacement control of the compressor 2 is executed. The capacity control of the compressor 2 is, for example, as shown in FIG.
It is determined whether the C switch 21 has been turned on. If the switch has not been turned on (N), the process proceeds to step 404, where the proportional component D of the capacity control duty ratio D output to the capacity control mechanism 9 is obtained.
p is set to “0”, and further proceeds to step 406, where the integral component Di (t
−Δt) is set to “0”, and in step 408, the capacity control duty ratio D is set to “0”.
At 00, the capacity control duty ratio D is 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%, the valve is fully closed and high pressure is not introduced into the back pressure chamber, so that the maximum capacity is achieved.

If it is determined in step 402 that the A / C switch 21 is turned on (Y), the process proceeds to step 410, 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 410, Te
1 is set to 2 ° C., and Te 2 is set to 15 ° C. In this step 410, the temperature is manually set 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 410.
The target evaporator temperature Teva_set is 15 ° C
It is desirable that

Then, the program proceeds to a step 420, wherein a 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. 13. First, in step 422, 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 410 by the characteristic line shown in FIG. Basically, when the temperature difference is −20 ° C., the proportional component Dp is “0%” and the temperature is + 20 ° C.
In this case, the proportional component Dp is calculated from the temperature difference based on the primary characteristic line that changes so that the proportional component Dp becomes “100%”.

Further, in step 424, FIG.
Based on the characteristic line shown in (b), the temperature difference (Teva-
Teva_set), a variation ΔDi of the integral component is calculated. Then, in step 326, the t-time integral component Di (t) is calculated by the equation ｛Di shown in step 426.
(T) = Di (t−Δt) + ΔDi｝ Note that this Δt is 100 msec.

Then, in step 428, it is determined whether or not the t-time integral component Di (t) is 50% or more. In step 430, the t-time integral component D (t) is determined.
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 42
8 to step 432, where the integral component Di is set to 50
[%], And the t-time integral component Di (t) is −5.
If it is not more than 0 [%], the process proceeds from step 430 to step 434 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 430
Then, the process proceeds to step 436 to set the t-time integral component Di (t) as the integral component Di as it is. Then, the integral component Di set in step 432, 434 or 436 and the proportional component Dp set in step 422 are set.
In step 438, the capacity calculation duty ratio DT is calculated (DT = Dp + Di). Then, in step 440, 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.

In step 450, it is determined whether or not the magnitude (| ΔEph |) of the rate of change ΔEph of the valve opening calculation duty ratio Eph is smaller than a predetermined value β1. In the determination in step 450, the change rate ΔE
If it is determined that the magnitude of ph is smaller than the predetermined value β1 (Y), the process proceeds to step 460 and proceeds to step 420
The capacity calculation duty ratio DT calculated in is set as the capacity control duty ratio D, and output in step 500.
In the determination in step 450, the change rate ΔE
If it is determined that the value of ph is equal to or larger than the predetermined value β1 (N), the process bypasses the step 460, so that the previous capacity control duty ratio D is output as it is in step 500, and the valve is opened. Calculation duty ratio DT set corresponding to the high pressure fluctuating due to the degree of fluctuation
, The pressure fluctuation in the high-pressure line 11 can be suppressed.

Hereinafter, other embodiments will be described, but the same steps or steps having the same effect will be denoted by the same reference numerals and description thereof will be omitted. In the second embodiment shown in FIG. 15, after the calculation of the capacity calculation duty ratio Dt in the step 420, instead of the determination of the change rate ΔEph of the valve opening calculation duty ratio Eph in the above-described step 450, expansion is performed. Pressure on the inlet side of valve 5,
The change rate ΔPh of the so-called high pressure PH of the refrigerant is a predetermined value β.
That is, a step 451 for determining whether or not the value is smaller than 2 is provided. Therefore, the variation of the expansion valve opening is determined by determining whether the variation of the high pressure PH, which is one factor for the expansion valve opening calculation, is smaller than a predetermined value β2. In addition, before the operation of the expansion valve 5, there is an advantage that the variation of the valve opening can be determined at the stage of the factor for calculating the valve opening calculation duty ratio Eph.

Further, the third embodiment shown in FIG.
Capacity calculation duty ratio Dt in step 420
After the calculation, the target high pressure, which is a factor for calculating the expansion valve opening in FIGS. 11A and 11B, instead of determining the change rate ΔEph of the valve opening calculation duty ratio Eph in step 450 described above. A step 452 for determining whether or not the difference (PHset-PH) between the pressure PHset and the actual inlet-side pressure PH of the expansion valve 5 is smaller than a predetermined value β3 is provided. Therefore, since the magnitude of the change in the valve opening is determined by a direct factor for calculating the opening of the expansion valve, the change in the valve opening can be determined before the operation of the expansion valve 5. Having.

In the first to third embodiments described above, when the fluctuation of the opening degree of the expansion valve is estimated to be large, the discharge capacity of the compressor 2 is set by setting the previous discharge capacity calculation duty ratio DT. Is limited, and in each embodiment, a judgment factor for judging (estimating) a change in the opening degree of the expansion valve is different.
Therefore, in the embodiment described below, since the method of limiting the discharge capacity of the compressor 2 is different, the valve opening calculation in step 450 is used as a determination factor for determining (estimating) the fluctuation of the expansion valve opening. Duty ratio Ep
The determination is made as to whether the magnitude (| ΔEph |) of the change rate ΔEph of h is smaller than a predetermined value β1.
Alternatively, the determination of 1 or the determination of step 452 may be used.

In the fourth embodiment shown in FIG.
In the determination of step 450, the magnitude | ΔEph | of the rate of change of the valve opening calculation duty ratio Eph is equal to the predetermined value β1.
If smaller (Y), proceed to step 460,
The capacity calculation duty ratio DT is set to the capacity control duty ratio D. Step 460 or step 4
After setting the capacity control duty ratio D at 08 to “0”, in step 461 the flag A is set to “0” to indicate that the discharge capacity of the compressor 2 has not been corrected, and the process proceeds to step 500. Output the capacity control duty ratio D.

If it is determined in step 450 that the magnitude | ΔEph | of the rate of change of the valve opening calculation duty ratio Eph is equal to or greater than the predetermined value β1 (N), the routine proceeds to step 470, where the flag is set. It is determined whether or not A is “0”, and if it is determined that the flag A is “0”, the process proceeds to step 471, where the rate of change ΔEph of the valve opening calculation duty ratio Eph is determined. A determination is made as to whether it is positive or negative (ΔEph <0?). If the rate of change ΔEph is negative (Y), it can be determined that the valve opening of the expansion valve 5 has largely changed in the increasing direction, so the routine proceeds to step 472, where the correction amount γ is calculated from the capacity calculation duty ratio DT. (For example, γ = 20%) is added to the capacity control duty ratio D to increase the discharge capacity of the compressor 2 and to suppress a sudden decrease in the high pressure PH caused by a sudden increase in the valve opening. It is. Then, the flow proceeds to step 474 to set "1" to the flag A, to set that the discharge capacity of the compressor 2 has been corrected, and to proceed to step 500 to output the capacity control duty ratio D. .

If it is determined in step 471 that the rate of change ΔEph is positive (N), it can be determined that the valve opening of the expansion valve 5 has largely changed in the decreasing direction. Proceeding to step 473, a correction amount γ (for example, γ = 2
0%) as a capacity control duty ratio D to reduce the discharge capacity of the compressor 2 and reduce the discharge capacity of the compressor 2 due to a sudden increase in high pressure caused by a rapid decrease in valve opening. It is controlled by. Then, the flow proceeds to step 474 to set "1" to the flag A, to set that the discharge capacity of the compressor 2 has been corrected, and to proceed to step 500 to output the capacity control duty ratio D. .

As described above, in the fourth embodiment, when the valve opening of the expansion valve fluctuates greatly in the direction of increasing the high-pressure pressure, the discharge is reduced in the direction of reducing the discharge capacity of the compressor. If the displacement is corrected and the fluctuation of the opening degree of the expansion valve fluctuates greatly in the direction of lowering the high pressure, the discharge capacity is corrected in the direction of increasing the discharge capacity of the compressor to prevent abnormal fluctuation of the high pressure. It is to suppress.

In the fifth embodiment shown in FIG. 18, when the magnitude | ΔEph | of the rate of change of the valve opening calculation duty ratio Eph is smaller than a predetermined value β1 (Y) in the determination at step 450, Goes to step 453, and sets the values of constants a, b, and c used in the calculation of the proportional component Dp of the capacity calculation duty ratio DT and the variation ΔDi of the integral component in FIGS. 14A and 14B to A1, B1,
Set to C1. For example, A1 = 20, B1 = 5, C1
= 0.05.

If the magnitude | ΔEph | of the rate of change of the valve opening calculation duty ratio Eph is equal to or larger than the predetermined value β1 in the determination at step 450 (N), the routine proceeds to step 454, and FIG. 14 (a) and 14 (b), constants a, b, used in the calculation of the change ΔDi of the proportional component Dp and the integral component of the capacity calculation duty ratio DT.
The numerical value of c is set to A2, B2, C2. For example, A2
= 40, B2 = 10, and C2 = 0.1.

Therefore, in the fifth embodiment, when the valve opening of the expansion valve 5 fluctuates greatly, the change of the proportional component Dp and the integral component of the capacity calculation duty ratio DT is calculated. 14 (a) and 14 (b), the values of the constants a, b and c of the characteristic lines are increased to reduce the rate of change of the characteristic lines. Fluctuation in discharge capacity can be suppressed,
It can suppress abnormal fluctuation of high pressure.

In the sixth embodiment shown in FIG. 19, when the magnitude | ΔEph | of the rate of change of the valve opening calculation duty ratio Eph is equal to or greater than the predetermined value β1 in the determination at step 450 (N). Proceeds to step 480 to determine whether or not “0” is set in the flag A. If the flag A is “0” (Y), the process proceeds to step 481 to execute the previous capacity calculation. The duty ratio DT is set to the reference duty ratio D0. Then, the reference duty ratio D0
Immediately after is set, "N" is determined in the determinations of step 482 and step 483. Therefore, in step 486, the capacity calculation duty ratio DT is directly set to the capacity control duty ratio D, and step 487 is performed.
In step 500, "1" is set in the flag A, and
Outputs a capacity control duty ratio D.

If it is determined again in step 450 that the fluctuation of the valve opening is large (N),
Since "1" is set in the flag A in the step 487, the determination in the step 480 becomes "N", so that the process proceeds to the step 482 bypassing the step 481, and the latest capacity control duty ratio D , Step 48
The reference duty ratio D0 set at 1 is λ (for example, 2
(D0 + λ) is determined. If it is determined in step 483 that the capacity control duty ratio D is larger than D0 + λ (Y), the process proceeds to step 484, where the capacity control duty ratio D
Is set so that the capacity control duty ratio D does not become larger than the previous capacity control duty ratio D0 by λ (20%) or more.

If the capacity control duty ratio D is equal to or less than D0 + λ in the determination at step 482 (N), the routine proceeds to step 483, where the capacity control duty ratio D
Is smaller than D0−λ. In the determination in step 483, the capacity control duty ratio D
If it is determined that the value is smaller than 0-λ (Y), the flow advances to step 485 to set the capacity control duty ratio D to D0-λ.
Is set so that the capacity control duty ratio D does not fall below the previous capacity control duty ratio D0-λ (20%).

If it is determined in steps 482 and 483 that the capacity control duty ratio D is within ± λ (20%) of the reference duty ratio D0, step 4
At 86, the capacity operation duty ratio DT is set to the capacity control duty ratio D as it is.

As described above, in the sixth embodiment, the valve opening of the expansion valve 5 fluctuates rapidly and the compressor 2
When the fluctuation of the discharge capacity increases or decreases by a predetermined value or more, the fluctuation of the discharge capacity of the compressor 2 is limited to suppress the fluctuation of the high pressure.

In the seventh embodiment shown in FIG. 20, when the magnitude | ΔEph | of the rate of change of the valve opening calculation duty ratio Eph is equal to or greater than the predetermined value β1 in the determination of step 450 (N), Proceeds to step 490, and determines whether or not the predetermined value β1 or more is the first time. If it is the first time (Y), the flow proceeds to step 491 to start the timer. Then, in step 492, it is determined whether or not the time (TIME) of the timer has become longer than a predetermined time α.
Proceeding to 0, the previous capacity control duty ratio D is output. If it is not the first time (N), the process goes from step 490 to step 492, bypassing step 491, and determines the timer time (TIME) again. If the timer time (TIME) is longer than the predetermined time α (Y), the process proceeds to step 459 to reset the timer, and at step 460, the latest capacity calculation duty ratio D
T is set to the capacity control duty ratio D.

As described above, in the seventh embodiment, when the valve opening of the expansion valve 5 fluctuates greatly, the previous displacement control duty ratio D is maintained for a predetermined time. Can be suppressed from changing in response to a rapid change in the valve opening.

Further, the calculation of the discharge capacity calculation duty ratio DT of the compressor 2 according to the eighth embodiment shown in FIG. 21 is performed, for example, in the flowchart of the calculation of the discharge capacity calculation duty ratio DT shown in FIG. A factor for suppressing a change in the displacement of the compressor 2 based on the ratio EXP is added. In this calculation flowchart, first, in step 421-1, numerical values G, H, and J are set for calculation constants a, b, and c. These values are, for example, G = 20, H = 5, J = 0.05
It is.

Then, in step 421-2, a proportional component calculation X factor X for calculating a proportional component Dp of the evaporator (wake) temperature Teva, the target evaporator temperature Teva-set, and the capacity calculation duty ratio DT.
_P is the expression shown in the block of step 421-2
[X_p = {Teva-e * (1-EXP / 100)}
-Teva_set]. In this equation, e is an arithmetic constant, and 5 is set for the set values 20, 5, 0, and 5 of the G, H, and J.

In this equation, as the valve opening duty ratio EXP of the expansion valve 5 increases, the actual pressure PH increases, but the evaporator temperature Teva e * (1
Since (−EXP / 100) component is subtracted, the change of the proportional component calculation X factor X_p is suppressed. Then, based on the proportional component calculation X component X_p, a step 42 is executed.
2, a proportional component Dp of the capacity calculation duty ratio DT is calculated from the characteristic line shown in FIG. At this time, since the change in the proportional component calculation X component X_p is suppressed, the change in the proportional component Dp of the discharge displacement calculation duty ratio DT is also suppressed.

Then, in step 423-1, a time differential value dEXP / d of the valve opening duty ratio EXP is obtained.
It is determined whether or not t is smaller than 0, and if dEXP / dt is smaller than 0 (Y), the flow advances to step 423-2 to calculate the X component X_i for the integral component calculation in step 4
Formula ｛X_i = (Te
va-Teva_set) / (1-dEXP / dt)}
If dEXP / dt is equal to or greater than 0 (N), the process proceeds to step 423-3, where the calculation of the X component X_i for the integral component calculation is performed by using the formula {} shown in the block of step 423-3. X_i = (Teva-Teva_
set) / (dEXP / dt + 1)}. Then, in step 424, a change ΔDi of the integral component Di of the capacity computation duty ratio DT is computed based on the characteristic line shown in FIG. 14B by the integral component computing X component X_i. Then, at step 426, the t-time integral component Di of the capacity calculation duty ratio DT
(T) is calculated, and thereafter, the capacity control duty ratio D is calculated as in the above-described embodiment.

As a result, steps 423-2 and 4
In the mathematical expression shown in 23-3, when the change in the valve opening duty ratio EXP decreases, dEXP / dt approaches 0, so the X component X_i for the integral component calculation is Teva.
As the value approaches −Teva_set, it becomes possible to calculate the change ΔEph_i of the equivalent component of the conventional equivalent. Further, when the change in the valve opening duty ratio EXP increases, dEXP / dt increases. Therefore, the denominator of the equation increases, the amount of calculation of the change ΔX_i decreases, and the sensitivity can be made lower than before. Becomes

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

[0060]

As described above, according to the present invention, the valve opening degree of the expansion valve or the change in the valve opening degree is determined at the calculation stage, and this is taken into account when calculating the discharge capacity of the compressor. Therefore, it is possible to avoid the response delay of the discharge capacity of the compressor, and to stabilize the pressure fluctuation of the refrigeration cycle at an early stage. In addition, since the displacement of the compressor can be controlled in consideration of the fluctuation of the opening degree of the expansion valve before the fluctuation, more appropriate control can be performed and the stable performance of the refrigeration cycle can be maintained.

[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 an electric expansion valve control routine according to the embodiment of the present invention.

FIG. 10 is a flowchart showing a valve opening calculation duty ratio Eph calculation routine in an electric expansion valve control routine according to the embodiment of the present invention.

FIG. 11A is a diagram illustrating a routine for calculating a valve opening degree duty ratio Eph according to an embodiment of the present invention, in which a proportional component Eph_p of the duty ratio is calculated from the temperature difference between the actual temperature of the evaporator and the target temperature. FIG. 4B is a characteristic diagram showing a characteristic line, and FIG. 4B shows a duty ratio based on a temperature difference between the actual temperature of the evaporator and the target temperature in the calculation routine of the valve opening calculation duty ratio Eph according to the embodiment of the present invention. FIG. 7 is a characteristic diagram showing a characteristic line for calculating a change ΔEph_i of the integral component of FIG.

FIG. 12 is a flowchart illustrating a compressor capacity control routine according to the first embodiment of the present invention.

FIG. 13 is a calculation routine of a capacity calculation duty ratio DT according to the embodiment of the present invention.

FIG. 14A is 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 capacity calculation duty ratio DT according to the embodiment of the present invention. (B) is a characteristic diagram showing a characteristic line for calculating a change ΔDi of the integral component component Di of the duty ratio from a temperature difference between the actual temperature of the evaporator and the target temperature.

FIG. 15 is a flowchart illustrating a compressor capacity control routine according to a second embodiment of the present invention.

FIG. 16 is a flowchart illustrating a compressor capacity control routine according to a third embodiment of the present invention.

FIG. 17 is a flowchart showing only a characteristic portion in a compressor capacity calculation routine according to a fourth embodiment of the present invention.

FIG. 18 is a flowchart showing only characteristic portions in a compressor capacity calculation routine according to a fifth embodiment of the present invention.

FIG. 19 is a flowchart showing only characteristic portions in a compressor capacity calculation routine according to a sixth embodiment of the present invention.

FIG. 20 is a flowchart showing only a characteristic portion in a compressor capacity calculation routine according to a seventh embodiment of the present invention.

FIG. 21 is a flowchart showing only characteristic portions in a compressor capacity calculation routine according to an eighth embodiment of the present invention.

[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

Claims (9)

[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. A compressor in which a discharge capacity of the compressor is changed in a refrigeration cycle including at least an expansion unit whose valve opening is varied by an external control signal and an evaporator that evaporates a low-pressure refrigerant flowing out of the expansion unit. A displacement control means, at least a valve opening control means for controlling a valve opening degree of the expansion means, wherein a control signal to the compressor displacement control means is a control signal outputted to the valve opening control means. A refrigeration cycle control device, wherein the refrigeration cycle control device is corrected based on the refrigeration cycle. 2. A high-pressure pressure detecting means for detecting a pressure of the high-pressure line; a refrigerant temperature detecting means for detecting a refrigerant temperature of a high-pressure line from a discharge side of the compressor to an inflow side of the expansion means; A target high pressure calculating means for calculating a target high pressure based on the refrigerant temperature detected by the detecting means; and a target high pressure calculated by the high pressure detecting means and the actual high pressure detected by the high pressure detecting means. A valve opening calculating means for calculating a valve opening of the expansion means; a valve opening control means for outputting a control signal to the expansion means based on the valve opening calculated by the valve opening calculating means; Air temperature detecting means for detecting a temperature of air passing through the evaporator; air temperature setting means for setting a target temperature of air passing through the evaporator; A discharge capacity calculating means for calculating a discharge capacity of the compressor based on a target temperature set by a setting means and an actual temperature detected by the air temperature detecting means; and a valve calculated by the valve opening degree calculating means. Valve opening degree determining means for determining the state of the opening degree; and a discharge capacity calculated by the discharge capacity calculating means when the state of the valve opening degree determined by the valve opening degree determining means matches a predetermined condition. 2. A compressor according to claim 1, further comprising: a displacement correcting means for correcting the displacement, and a compressor displacement controlling means for outputting a control signal to the compressor based on the displacement corrected by the displacement correcting means.
A refrigeration cycle control device according to the above. 3. The discharge capacity correction means limits the discharge capacity calculated by the discharge capacity calculation means when the change in the valve opening is equal to or more than a predetermined value. Refrigeration cycle control device. 4. A high-pressure pressure detecting means for detecting a pressure of the high-pressure line; a refrigerant temperature detecting means for detecting a refrigerant temperature of a high-pressure line from a discharge side of the compressor to an inflow side of the expansion means; A target high pressure calculating means for calculating a target high pressure based on the refrigerant temperature detected by the detecting means; and a target high pressure calculated by the high pressure detecting means and the actual high pressure detected by the high pressure detecting means. A valve opening calculating means for calculating a valve opening of the expansion means; a valve opening control means for outputting a control signal to the expansion means based on the valve opening calculated by the valve opening calculating means; Air temperature detecting means for detecting a temperature of air passing through the evaporator; air temperature setting means for setting a target temperature of air passing through the evaporator; Discharge capacity calculating means for calculating the discharge capacity of the compressor based on the target temperature set by the setting means and the actual temperature detected by the air temperature detecting means; and a high pressure detected by the high pressure detecting means. High pressure fluctuation determination means for detecting the fluctuation of the discharge capacity, discharge capacity correction means for correcting the discharge capacity calculated by the discharge capacity calculation means when the high pressure fluctuation by the high pressure change determination means matches a predetermined condition, 2. A compressor displacement control means for outputting a control signal to said compressor based on the discharge displacement corrected by said discharge displacement correction means.
A refrigeration cycle control device according to the above. 5. The discharge capacity correction means limits the discharge capacity calculated by the discharge capacity calculation means when the high-pressure change determination means determines that the pressure fluctuation is equal to or greater than a predetermined value. The refrigeration cycle control device according to claim 4, wherein: 6. A high-pressure pressure detecting means for detecting a pressure of the high-pressure line; a refrigerant temperature detecting means for detecting a refrigerant temperature of a high-pressure line from a discharge side of the compressor to an inflow side of the expansion means; A target high pressure calculating means for calculating a target high pressure based on the refrigerant temperature detected by the detecting means; and a target high pressure calculated by the high pressure detecting means and the actual high pressure detected by the high pressure detecting means. A valve opening calculating means for calculating a valve opening of the expansion means; a valve opening control means for outputting a control signal to the expansion means based on the valve opening calculated by the valve opening calculating means; Air temperature detecting means for detecting a temperature of air passing through the evaporator; air temperature setting means for setting a target temperature of air passing through the evaporator; Discharge capacity calculating means for calculating the discharge capacity of the compressor based on the target temperature set by the setting means and the actual temperature detected by the air temperature detecting means; and a high pressure detected by the high pressure detecting means. When,
A pressure difference calculating means for calculating a pressure difference from the target high pressure calculated by the target high pressure calculating means; and a pressure difference for determining whether or not the pressure difference calculated by the pressure difference calculating means meets a predetermined condition. Determining means; discharging capacity correcting means for correcting the discharging capacity calculated by the discharging capacity calculating means when the pressure difference determining means determines that the pressure difference meets a predetermined condition; 2. A compressor displacement control means for outputting a control signal to the compressor based on the corrected discharge displacement.
A refrigeration cycle control device according to the above. 7. The discharge capacity correction means limits the discharge capacity calculated by the discharge capacity calculation means when the pressure difference determination means determines that the pressure difference is equal to or greater than a predetermined value. The refrigeration cycle control device according to claim 6, wherein 8. A high-pressure pressure detecting means for detecting a pressure of the high-pressure line, a refrigerant temperature detecting means for detecting a refrigerant temperature of a high-pressure line from a discharge side of the compressor to an inflow side of the expansion means, and the refrigerant temperature A target high pressure calculating means for calculating a target high pressure based on the refrigerant temperature detected by the detecting means; and a target high pressure calculated by the high pressure detecting means and the actual high pressure detected by the high pressure detecting means. A valve opening calculating means for calculating a valve opening of the expansion means; a valve opening control means for outputting a control signal to the expansion means based on the valve opening calculated by the valve opening calculating means; Air temperature detecting means for detecting a temperature of air passing through the evaporator; air temperature setting means for setting a target temperature of air passing through the evaporator; Discharge capacity calculating means for calculating the discharge capacity of the compressor based on the target temperature set by the setting means, the actual temperature detected by the air temperature detecting means and the valve opening calculated by the valve opening calculating means; And a compressor displacement control means for outputting a control signal to the compressor based on the discharge displacement corrected by the discharge displacement calculation means.
A refrigeration cycle control device according to the above. 9. The discharge capacity calculation means calculates a discharge capacity of the compressor based on a target temperature set by the air temperature setting means and an actual temperature detected by the air temperature detection means, and 9. The refrigeration cycle control device according to claim 8, wherein the displacement of the compressor is corrected using the valve opening calculated by the valve opening calculating means as a factor.