JP6485256B2 - Refrigeration cycle equipment - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus.

  Conventionally, in the refrigeration cycle, by adjusting the opening of the expansion valve, the subcool control is performed so that the supercooling degree (subcool) of the refrigerant at the outlet of the condenser approaches the supercooling target value (target temperature). Is widely known (see, for example, Patent Document 1). In such a refrigeration cycle, energy efficiency can be improved by setting the subcooling of the refrigerant at the outlet of the condenser to an optimum value.

JP-A-5-106940

  In the refrigeration cycle that performs the subcool control as described above, the subcool of the refrigerant at the outlet of the condenser is detected, and feedback control is performed so that the subcool approaches the supercooling target value.

  However, in such a refrigeration cycle, for example, when the system is started in the heating mode or when the set temperature is changed to a high temperature, the refrigerant that temporarily flows out of the condenser may be in a gas-liquid two-phase state. is there. As described above, when the refrigerant flowing out of the condenser enters a gas-liquid two-phase state, it is detected as subcool = 0 ° C., and an appropriate operation amount of the expansion valve cannot be determined.

  For this reason, in such a refrigeration cycle, when the subcool = 0 ° C. is detected, the operation amount of the expansion valve is set to a constant value, and feedback control is performed so that the subcool approaches the target value. However, when the operation amount of the expansion valve is set small, it takes a long time for the subcool to reach the target value, and the energy loss during that time increases. Further, when the operation amount of the expansion valve is set to be large, subcool overshoot and hunting occur, and temperature unevenness occurs in the air-conditioning wind, which causes discomfort to the passenger.

  The present invention has been made in view of the above problems, and an object thereof is to improve energy efficiency while improving passenger comfort.

  In order to achieve the above-mentioned object, the invention described in claim 1 includes a compressor (11) that compresses and discharges a refrigerant, a condenser (12) that dissipates heat from the refrigerant discharged from the compressor, and electrically The expansion valve (13) for reducing the pressure of the refrigerant flowing out of the condenser with the valve opening adjusted, the evaporator (14) for absorbing heat by evaporating the refrigerant decompressed by the expansion valve, and the refrigerant at the outlet of the condenser Supercooling degree detection means (S100) for detecting the degree of supercooling, and control of the opening degree of the expansion valve so as to bring the supercooling degree of the refrigerant at the condenser outlet detected by the supercooling degree detection means close to the supercooling target value Expansion valve control means (S106). Further, a physical quantity detection means (S101) for detecting a physical quantity correlated with the dryness of the refrigerant at the condenser outlet, and a condenser outlet detected by the supercooling degree detection means based on the physical quantity detected and detected by the physical quantity detection means. Correction means (S102) for correcting the degree of supercooling of the refrigerant.

  According to such a configuration, the physical quantity correlated with the dryness of the refrigerant at the condenser outlet is detected, and the degree of supercooling of the refrigerant at the condenser outlet is corrected based on this physical quantity. That is, when the refrigerant at the condenser outlet is in a gas-liquid two-phase state, the supercooling degree of the refrigerant at the condenser outlet is corrected based on a physical quantity that correlates with the dryness of the refrigerant at the condenser outlet. Since the opening degree of the expansion valve is controlled so as to bring the degree of cooling closer to the supercooling target value, it is possible to quickly achieve a supercooling state with good energy efficiency, and to improve the energy efficiency. Moreover, since overshoot and hunting of the degree of supercooling are reduced, passenger comfort can be improved.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a figure which shows the structure of the refrigerating-cycle apparatus which concerns on one Embodiment of this invention. It is the Mollier diagram which showed the state of the refrigerant | coolant at the time of implementing subcool control from the state with the large dryness of a refrigerant | coolant. FIG. 3 is a Mollier diagram showing the state of the refrigerant when the subcool control is performed from a state where the dryness of the refrigerant is smaller than the state shown in FIG. 2. FIG. 4 is a diagram showing the response characteristics of the temperature change of the refrigerant in the state shown in FIG. 2 and the temperature change of the refrigerant in the state shown in FIG. 3. It is a figure for demonstrating to the inclination of a temperature characteristic. It is a flowchart of a control apparatus. It is the Mollier diagram which showed the state of the refrigerant | coolant when a refrigerant | coolant will be in a supercooled state. It is a comparative example showing the response characteristics of the degree of supercooling and the expansion valve opening when the subcool control is performed by setting the operation amount of the expansion valve to a constant value when subcool = 0 is detected. It is a comparative example showing the response characteristics of the degree of supercooling and the expansion valve opening when the subcool control is performed by setting the operation amount of the expansion valve to a constant value when subcool = 0 is detected. It is the figure which showed the response characteristic of the supercooling degree of subcool control by the control apparatus of this invention, and an expansion valve opening degree.

  A configuration of a refrigeration cycle apparatus 10 according to an embodiment of the present invention is shown in FIG. The refrigeration cycle apparatus 10 is mounted on a vehicle air conditioner for an electric vehicle or a hybrid vehicle that obtains a driving force for vehicle traveling from a traveling electric motor. The refrigeration cycle apparatus 10 performs air conditioning (cooling and heating) in the passenger compartment.

  The refrigeration cycle apparatus 10 includes a compressor 11, a condenser 12, an expansion valve 13, an evaporator 14, a control device 50, a refrigerant temperature sensor 51, a refrigerant pressure sensor 52, and the like. The compressor 11, the condenser 12, the expansion valve 13, and the evaporator 14 are connected in order via piping.

  As the heat medium, that is, the refrigerant circulating in the refrigeration cycle apparatus 10, a chlorofluorocarbon refrigerant (for example, R134a) is employed. This refrigeration cycle apparatus 10 is a subcritical cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant.

  The compressor 11 is disposed in an engine room (not shown), sucks refrigerant in the refrigeration cycle apparatus 10, compresses and discharges it, and is driven by an electric motor (not shown). It is a compressor. As the electric compressor, various compression mechanisms such as a scroll compression mechanism and a vane compression mechanism can be adopted. The electric motor is an AC motor whose operation is controlled by an AC current output from an inverter (not shown). The operation of the compressor 11 is controlled by a control signal output from the control device 50.

  The condenser 12 is a radiator that is disposed in the engine room and heat-condenses the refrigerant discharged from the compressor 11 by exchanging heat between the refrigerant flowing through the inside and the outside air blown from a blower (not shown).

  The expansion valve 13 is a decompressor that electrically adjusts the valve opening and decompresses the refrigerant that has flowed out of the condenser 12. The expansion valve 13 includes a valve body configured to be able to change the passage opening (throttle opening) of the refrigerant passage 20 between the condenser 12 and the evaporator 14, and a stepping that changes the throttle opening of the valve body. This is an electric variable aperture mechanism that includes an electric actuator including a motor. The operation of the electric actuator is controlled by a control signal output from the control device 50.

  The evaporator 14 evaporates the refrigerant decompressed and expanded by the expansion valve 13 and exerts an endothermic effect on the refrigerant.

  The refrigerant temperature sensor 51 detects the temperature of the refrigerant flowing out of the condenser 12, and outputs a signal indicating the detected refrigerant temperature to the control device 50. The refrigerant temperature sensor 51 is provided outside the condenser outlet pipe, and detects the temperature of the condenser outlet pipe. The refrigerant pressure sensor 52 detects the pressure of the refrigerant flowing out of the condenser 12 and outputs a signal indicating the detected refrigerant temperature to the control device 50.

  The control device 50 is composed of a well-known microcomputer including a CPU, ROM, RAM, EEPROM, etc. that constitute storage means and its peripheral circuits, and performs various arithmetic processing based on an air conditioning control program stored in the ROM. Control the operation of various connected devices.

  The control device 50 of the refrigeration cycle apparatus 10 detects the degree of subcooling (subcool) SC and performs subcool control so that the degree of supercooling approaches the supercooling target value. Here, the subcool control will be described.

  In the subcool control, first, the degree of supercooling (subcool) SC of the refrigerant flowing out of the condenser 12 is detected. The degree of supercooling SC of the present embodiment is defined by the temperature difference between the current temperature of the liquid-phase refrigerant and the saturated liquid refrigerant having the same pressure. Specifically, based on the saturation temperature Tp (n) of the refrigerant flowing out of the condenser 12 and the temperature Ts (n) of the refrigerant flowing out of the condenser 12, the flow out of the condenser 12 using Equation 1 shown below. The supercooling degree (subcool) SC of the refrigerant is calculated.

(Equation 1)
SC = Tp (n) -Ts (n)
The refrigerant saturation temperature Tp (n) is determined with reference to a map stored in advance in the storage means from the pressure detected by the refrigerant pressure sensor 52, that is, the pressure of the refrigerant flowing out of the condenser 12. The refrigerant temperature Ts (n) is the temperature detected by the refrigerant temperature sensor 51, that is, the temperature of the refrigerant flowing out of the condenser 12.

  In the state of the liquid refrigerant, since the supercooling degree SC of the refrigerant can be detected using Equation 1, an appropriate operation amount of the expansion valve can be determined. However, the refrigerant flowing out of the condenser 12 is in a state in which the gas-phase refrigerant and the liquid-phase refrigerant are mixed (the gas flows) until the refrigerant flowing out of the condenser 12 becomes a liquid-phase refrigerant after the compressor 11 starts operating. Liquid two-phase state). In this gas-liquid two-phase state, the degree of supercooling = 0 is detected, the state quantity of the refrigerant cannot be specified, and the proper operation amount of the expansion valve cannot be determined. If the state quantity (dryness) of the refrigerant can be measured, an appropriate operation amount of the expansion valve can be determined, but the dryness of the refrigerant cannot be easily measured. Here, the dryness is a mass ratio occupied by a gas phase portion in a gas-liquid two-phase fluid.

  Therefore, in the present embodiment, the change rate of the refrigerant temperature is obtained as a physical quantity correlated with the dryness of the refrigerant, and the supercooling degree SC of the refrigerant is corrected based on the change rate of the refrigerant temperature.

  Here, the relationship between the degree of dryness of the refrigerant and the temporal change in the refrigerant temperature detected by the refrigerant temperature sensor 51 will be described. FIG. 2 is a Mollier diagram showing the state of the refrigerant when the subcool control is performed from the state where the degree of dryness of the refrigerant is large. FIG. 3 is a Mollier diagram showing the state of the refrigerant when the subcool control is performed from the state where the dryness of the refrigerant is smaller than the state shown in FIG. FIG. 4 is a diagram illustrating a change in the temperature of the refrigerant detected by the refrigerant temperature sensor 51 after a predetermined time has elapsed since the compressor 11 started operating. FIG. 4 shows the time change of the saturation temperature (temperature characteristic G1), the temperature change of the refrigerant in the state shown in FIG. 2 (temperature characteristic G2), and the response characteristic (temperature characteristic) of the temperature change of the refrigerant in the state shown in FIG. G3) is shown.

  As shown in FIG. 2, when the subcool control is performed from a state where the dryness of the refrigerant is large, the temperature of the refrigerant changes as shown by the temperature characteristic G2 in FIG. Further, as shown in FIG. 3, when the subcool control is performed from a state where the dryness of the refrigerant is large, the temperature of the refrigerant changes as shown by the temperature characteristic G3 in FIG.

  In FIG. 4, the temperature characteristic G <b> 1 is a time change of a saturation temperature described later. The temperature characteristic G1 is a change with time of the saturation temperature specified by referring to the map from the refrigerant pressure detected using the refrigerant pressure sensor 52. In FIG. 4, temperature characteristics G <b> 2 and G <b> 3 are detection values of the refrigerant temperature sensor 51.

Here, as shown in FIG. 5, for example, the slope of the temperature characteristic G2 is, Ts (n) the temperature at time _{t n,} the temperature at time _{t n-1} When Ts (n-1), ( Ts ( n) −Ts (n−1)) / (t _n −t _n−1 ).

  Since the refrigerant pressure sensor 52 has a faster response speed than the refrigerant temperature sensor 51, the gradient of the temperature characteristic G1 specified based on the output value of the refrigerant pressure sensor 52 is large. On the other hand, since the refrigerant temperature sensor 51 has a slower response speed than the refrigerant pressure sensor 52, the temperature characteristics G2 and G3 have a smaller inclination than the temperature characteristic G1.

  As shown in FIG. 4, the temperature characteristics G2 and the temperature characteristics G3 have different rates of change. This means that the rate of change in temperature detected by the refrigerant temperature sensor 51 differs depending on the degree of dryness. Specifically, when the subcool control is performed from a state where the degree of dryness of the refrigerant is large, the change rate of the temperature of the refrigerant detected by the refrigerant temperature sensor 51 is controlled from the state where the degree of dryness of the refrigerant is smaller. In this case, the change rate of the temperature of the refrigerant detected by the refrigerant temperature sensor 51 becomes larger.

  In the present embodiment, the change rate of the refrigerant temperature is obtained as a physical quantity correlated with the dryness of the refrigerant, and the supercooling degree SC of the refrigerant is corrected based on the change rate of the refrigerant temperature. Specifically, the subcooling degree SC of the refrigerant is corrected using Equation 2 shown below.

(Equation 2)
SC = Tp (n) -Ts (n)-[alpha] (Ts (n) -Ts (n-1))
Here, Ts (n) −Ts (n−1) included on the right side represents the change amount (change rate) of the temperature of the refrigerant. Α is a constant and is set to an optimum value by evaluation. The appropriate α varies depending on the heat capacity of the refrigerant temperature sensor 51 and the like, and therefore is determined in consideration of the influence on the expansion valve 13. The correction term included in the right side = −α (Ts (n) −Ts (n−1)) represents a margin until supercooling occurs. The degree of supercooling and the degree of dryness are physical quantities having different dimensions, but the constant α is used to regard the degree of supercooling of the refrigerant as a negative value.

  When the refrigerant is in a gas-liquid two-phase state, the correction term included in the right side = −α (Ts (n) −Ts (n−1)) is a negative value corresponding to the degree of dryness. Note that when the refrigerant is in a gas-liquid two-phase state, Tp (n) −Ts (n) = 0, and therefore the right side of Equation 2 is a negative value corresponding to the dryness as a whole.

  When the refrigerant is in a saturated liquid state, the correction term included in the right side = −α (Ts (n) −Ts (n−1)) is equal to Tp (n) −Ts (n) included in the right side. . Therefore, the right side of Equation 2 is 0 as a whole.

  Further, as shown in the temperature characteristic G3, the temperature characteristics G2 in FIG. 4 have the change speeds (gradients) of the temperature characteristics G2 and G3 to 0 with time. As described above, when the change speed (gradient) of the temperature characteristics G2 and G3 becomes zero, the correction term included in the right side = −α (Ts (n) −Ts (n−1)) becomes zero. For this reason, when the subcool occurs (supercooled state), the correction term included in the right side = −α (Ts (n) −Ts (n−1)) does not affect the value of the supercooling degree SC. .

  Thus, if the refrigerant subcooling degree SC is corrected based on the change rate of the refrigerant temperature, next, a deviation ΔSC between the supercooling target value TSC and the subcooling degree SC is calculated. The deviation ΔSC can be calculated using Equation 3 below.

(Equation 3)
ΔSC = TSC−SC
Next, the expansion valve operation amount of the expansion valve 13 is determined based on the deviation, and the throttle opening of the expansion valve 13 is adjusted according to the expansion valve operation amount. The expansion valve operation amount is determined using a function f (ΔSC) having a deviation ΔSC between the supercooling target value TSC and the supercooling degree SC as a variable.

  Hereinafter, the process in the subcool control of the control device 50 will be described with reference to the flowchart shown in FIG. When the predetermined reference time elapses after the compressor 11 starts operating, the control device 50 performs the process shown in FIG. In addition, each control step in the flowchart of each drawing comprises the various function implementation | achievement means which the control apparatus 50 has.

  First, in S100 of FIG. 2, the control device 50 detects the degree of supercooling SC of the refrigerant that has flowed out of the condenser 12. Specifically, as described above, the refrigerant saturation temperature Tp (n) and the refrigerant temperature Ts (n) flowing out of the condenser 12 are specified, and the refrigerant saturation temperature Tp (n) and the refrigerant temperature Ts (n) are identified. ) To detect the supercooling degree (subcool) SC of the refrigerant using the above formula 1. The control device 50 stores the refrigerant temperature Ts (n) detected by the refrigerant temperature sensor 51 in the RAM.

  In the next S101, the control device 50 detects the change rate of the temperature of the refrigerant at the outlet of the condenser 12 as a physical quantity correlated with the dryness of the refrigerant at the outlet of the condenser 12. Specifically, Ts (n) −Ts (n−1) in Equation 2 is calculated. Here, Ts (n−1) in Equation 2 is the temperature of the refrigerant determined in the previous S110, and can be read from the RAM. Ts (n) is the temperature of the refrigerant determined in this S110.

  In next step S102, the supercooling degree SC of the refrigerant is corrected by the following formula 2. Specifically, the subcooling degree SC of the refrigerant is corrected using Equation 2 shown below. Specifically, the subcooling degree SC of the refrigerant is corrected by using the above-described formula 2.

  Thus, the change rate of the refrigerant temperature is obtained as a physical quantity correlated with the dryness of the refrigerant, and the subcool degree SC of the refrigerant is corrected based on the change rate of the refrigerant temperature.

  In the next S104, the deviation ΔSC between the supercooling target value TSC and the supercooling degree SC is calculated using the above-described equation 3.

  In the next S106, the expansion valve operation amount of the expansion valve 13 is determined based on the deviation ΔSC calculated in S104, and the throttle opening of the expansion valve 13 is adjusted according to the expansion valve operation amount. The expansion valve operation amount is determined using a function f (ΔSC) having a deviation ΔSC between the supercooling target value TSC and the supercooling degree SC as a variable.

  In the next S108, it is determined whether or not a certain time (for example, 1 second) has elapsed. If the predetermined time has not elapsed, the determination in S108 is NO and the determination in S108 is repeated.

  If a predetermined time has elapsed, the determination in S108 is YES, the process returns to S100, and the above-described processing is repeatedly performed.

  FIG. 7 is a Mollier diagram showing the state of the refrigerant when the outlet refrigerant of the condenser 12 is in a supercooled state. As described above, when the outlet refrigerant of the condenser 12 is in a supercooled state, the correction term on the right side of the equation 2 = −α (Ts (n) −Ts (n−1)) becomes 0, and the degree of supercooling SC = The degree of supercooling is specified as Tp (n) -Ts (n). Then, the subcool control is continued so that the degree of supercooling SC approaches the supercooling target value TSC.

  FIGS. 8 and 9 are comparative examples in which when the subcool = 0 ° C. is detected, the operation amount of the expansion valve is set to a constant value and feedback control is performed so that the subcool approaches the target value.

  FIG. 8 is a diagram showing the response characteristics of the degree of supercooling and the opening degree of the expansion valve when the operation amount of the expansion valve is set small. (A) has shown the response characteristic of the subcooling degree, (b) has shown the response characteristic of the expansion valve opening degree.

  Thus, when the operation amount of the expansion valve is set to be small, it takes a long time for the degree of supercooling to reach the supercooling target value, and the energy loss during that time increases.

  FIG. 9 is a diagram showing the response characteristics of the degree of supercooling and the opening degree of the expansion valve when the operation amount of the expansion valve is set large. (A) has shown the response characteristic of the subcooling degree, (b) has shown the response characteristic of the expansion valve opening degree.

  As described above, when the operation amount of the expansion valve is set to be large, overshoot or hunting of the degree of supercooling occurs, and temperature unevenness occurs in the conditioned air, resulting in discomfort to the passenger.

  FIG. 10 is a diagram showing the response characteristics of the degree of supercooling and the expansion valve opening at the time of starting the system by the subcool control according to the present embodiment. (A) shows the response characteristic of the degree of supercooling, and (b) shows the response characteristic of the throttle opening of the expansion valve 13.

  As shown in FIG. 9, in the subcool control of the present embodiment, the degree of supercooling becomes a negative value due to correction in the gas-liquid two-phase state at the time of starting the system, approaches the positive constant value relatively quickly, and expands. The throttle opening of the valve 13 is also quickly adjusted to the optimum opening. Thus, since the degree of supercooling quickly approaches the supercooling target value, energy efficiency can be improved. Further, since overshoot and hunting of the degree of supercooling are suppressed, it is possible to reduce discomfort to the passenger.

  According to the configuration described above, a physical quantity that correlates with the dryness of the refrigerant at the outlet of the condenser 12 is detected as a change rate of the temperature of the refrigerant at the outlet of the condenser 12, and the outlet of the condenser 12 is detected based on the change rate of the temperature of the refrigerant. The degree of supercooling of the refrigerant is corrected. That is, when the refrigerant at the outlet of the condenser 12 is in a gas-liquid two-phase state, the degree of supercooling of the refrigerant at the outlet of the condenser 12 is determined based on the change rate of the temperature of the refrigerant that correlates with the dryness of the refrigerant at the outlet of the condenser 12. Since the valve opening of the expansion valve 13 is controlled so that the corrected degree of supercooling is brought close to the supercooling target value, the supercooling state with good energy efficiency can be quickly achieved, and the energy efficiency can be improved. Improvements can be made. Moreover, since overshoot and hunting of the degree of supercooling are reduced, passenger comfort can be improved.

  Further, when the refrigerant at the outlet of the condenser 12 is in a gas-liquid two-phase state, the refrigeration cycle apparatus corrects the supercooling degree of the refrigerant at the outlet of the condenser detected by the supercooling degree detection means to be regarded as a negative value. can do.

  In addition, this invention is not limited to the said embodiment, Based on the meaning of this invention, it can implement with a various form.

  (1) In the above embodiment, the change rate of the refrigerant temperature is obtained as a physical quantity correlated with the dryness of the refrigerant flowing out of the condenser 12, and the supercooling degree SC of the refrigerant is corrected based on the change rate of the refrigerant temperature. However, for example, if it is possible to use a dryness sensor that measures the dryness of the refrigerant flowing out of the condenser 12, the measured value of the dryness sensor is used to correct the supercooling degree SC of the refrigerant. It may be.

  (2) In the above embodiment, the temperature outside the pipe through which the refrigerant flowing out from the condenser 12 is detected as the physical quantity correlated with the dryness of the refrigerant flowing out from the condenser 12 is detected. Then, the change rate of the temperature outside the pipe through which the refrigerant flows is obtained, and the supercooling degree SC of the refrigerant is corrected based on the change rate of the refrigerant temperature. For example, the refrigerant flowing out of the condenser 12 is corrected. As a physical quantity correlated with the degree of dryness, the temperature of the refrigerant flowing out of the condenser 12 may be directly detected, and the supercooling degree SC of the refrigerant may be corrected based on the change rate of the temperature of the refrigerant. Further, the heat transfer coefficient from the refrigerant flowing out of the condenser 12 to the refrigerant temperature sensor is obtained based on a physical quantity correlated with the dryness of the refrigerant flowing out of the condenser 12, and the dryness of the refrigerant is estimated from this heat transfer coefficient. The refrigerant subcooling degree SC may be corrected based on the dryness of the refrigerant. In addition, when the sensor which detects the temperature outside the piping through which the refrigerant | coolant which flowed out from the condenser 12 flows is provided, the heat transfer rate from the refrigerant | coolant which flowed out of the condenser 12 to piping changes according to a dryness. As a result, the change speed of the refrigerant temperature detected by the sensor changes, and when a sensor for directly detecting the temperature of the refrigerant flowing out of the condenser 12 is provided, the refrigerant flows out of the condenser 12 according to the dryness. As the heat transfer coefficient from the refrigerant to the sensor changes, the change rate of the refrigerant temperature detected by the sensor changes.

  In addition, this invention is not limited to above-described embodiment, In the range described in the claim, it can change suitably. Further, in each of the above embodiments, when numerical values such as the number, numerical value, quantity, range, etc. of the constituent elements of the embodiment are mentioned, it is clearly limited to a specific number when clearly indicated as essential and in principle. The number is not limited to the specific number except for the case. In each of the above embodiments, when referring to the material, shape, positional relationship, etc. of the constituent elements, etc., unless otherwise specified, or in principle limited to a specific material, shape, positional relationship, etc. The material, shape, positional relationship, etc. are not limited.

  The correspondence relationship between the configuration of the above embodiment and the configuration of the claims will be described. S100 corresponds to the supercooling degree detection means, S106 corresponds to the expansion valve control means, and the refrigerant at the condenser outlet dries out. S102 corresponds to a physical quantity detection unit that detects a physical quantity that correlates with the degree, S102 corresponds to a correction unit, and the refrigerant temperature sensor 51 corresponds to a temperature detection unit.

DESCRIPTION OF SYMBOLS 10 Refrigeration cycle apparatus 11 Compressor 12 Condenser 13 Expansion valve 14 Evaporator 50 Control apparatus 51 Refrigerant temperature sensor 52 Refrigerant pressure sensor

Claims (3)

A compressor (11) for compressing and discharging the refrigerant;
A condenser (12) for dissipating heat from the refrigerant discharged from the compressor;
An expansion valve (13) whose valve opening is electrically adjusted to depressurize the refrigerant flowing out of the condenser;
An evaporator (14) for absorbing heat by evaporating the refrigerant decompressed by the expansion valve;
Supercooling degree detection means (S100) for detecting the degree of supercooling of the refrigerant at the outlet of the condenser;
Expansion valve control means (S106) for controlling the valve opening degree of the expansion valve so as to bring the supercooling degree of the refrigerant at the outlet of the condenser detected by the supercooling degree detection means close to the supercooling target value;
Physical quantity detection means (S101) for detecting a physical quantity correlated with the dryness of the refrigerant at the outlet of the condenser;
Correction means (S102) for correcting the degree of supercooling of the refrigerant at the condenser outlet detected by the supercooling degree detection means based on the physical quantity detected by the physical quantity detection means. Refrigeration cycle equipment.   The physical quantity detection means has a temperature detection means (51) for detecting the temperature of the refrigerant at the condenser outlet, and the change rate of the temperature of the refrigerant at the condenser outlet detected by the temperature detection means is used as the physical quantity. The refrigeration cycle apparatus according to claim 1, wherein the refrigeration cycle apparatus is detected.   The correction means corrects the supercooling degree of the refrigerant at the condenser outlet detected by the supercooling degree detection means to be regarded as a negative value when the refrigerant at the condenser outlet is in a gas-liquid two-phase state. The refrigeration cycle apparatus according to claim 1 or 2, wherein

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