Refrigeration cycle device

Abstract

A refrigeration cycle device is provided with a pressure reduction unit (14, 142), an evaporation unit (15), a pressure reduction control unit (20b), a pressure detection unit (21a), and a temperature detection unit (21b). The pressure detection unit (21a) detects the outlet-side pressure (Pe) of the refrigerant on the outlet side of the evaporation unit (15). The temperature detection unit (21b) detects the outlet-side temperature (Te) of the refrigerant on the outlet side of the evaporation unit (15). The pressure reduction control unit (20b) controls the operation of the pressure reduction units (14, 142) using at least the outlet-side pressure (Pe) and a delayed outlet-side temperature (Ted) at which the outlet-side temperature (Te) has been delayed.

Description

[0001] Cross-reference to related applications

[0002] This application is based on Japanese Patent Application No. 2022-108326 filed on July 5, 2022 and Japanese Patent Application No. 2022-206823 filed on December 23, 2022, and the contents thereof are incorporated herein by reference. Technical Field

[0003] The present invention relates to a refrigeration cycle device having an electric expansion valve. Background Art

[0004] Conventionally, Patent Document 1 discloses a refrigeration cycle device having an electric expansion valve as a decompression unit for decompressing a refrigerant. In the refrigeration cycle device of Patent Document 1, the operation of the electric expansion valve is controlled by PID control so that the superheat of the refrigerant on the outlet side of the evaporator approaches a target superheat. Furthermore, in the refrigeration cycle device of Patent Document 1, a value obtained by subtracting the temperature of the refrigerant on the inlet side of the evaporator from the temperature of the refrigerant on the outlet side of the evaporator is used as the superheat of the refrigerant on the outlet side of the evaporator.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 60-178254

[0008] However, if the value obtained by subtracting the temperature of the refrigerant at the inlet side of the evaporator from the temperature of the refrigerant at the outlet side of the evaporator is used as the superheat of the refrigerant at the outlet side of the evaporator as in the refrigeration cycle device of Patent Document 1, the actual superheat of the refrigerant at the outlet side may not be detected with high accuracy. For example, when the flow rate of the refrigerant flowing out of the evaporator increases with the change of the operating conditions, even if the superheat is detected, particles of liquid phase refrigerant (hereinafter referred to as droplets) may be mixed in the actual refrigerant at the outlet side.

[0009] Therefore, in the refrigeration cycle device of Patent Document 1, when the operating conditions change, appropriate control of the pressure reducing unit cannot be achieved, which may lead to a decrease in the refrigeration capacity of the evaporator and liquid compression of the compressor. Summary of the invention

[0010] In view of the above-mentioned points, an object of the present invention is to provide a refrigeration cycle device capable of realizing appropriate control of a decompression unit according to operating conditions.

[0011] In order to achieve the above-mentioned object, a refrigeration cycle device according to a first aspect of the present invention includes a decompression unit, an evaporation unit, a decompression control unit, a pressure detection unit, and a temperature detection unit.

[0012] The decompression unit decompresses the refrigerant. The evaporation unit evaporates the refrigerant decompressed by the decompression unit. The decompression control unit controls the operation of the decompression unit. The pressure detection unit detects the outlet side pressure of the refrigerant at the outlet side of the evaporation unit. The temperature detection unit detects the outlet side temperature of the refrigerant at the outlet side of the evaporation unit.

[0013] The pressure reducing control unit controls the operation of the pressure reducing unit using the outlet side pressure and the delayed outlet side temperature obtained by delaying the outlet side temperature.

[0014] Thus, the decompression control unit uses at least the outlet side pressure and the delayed outlet side temperature to control the operation of the decompression unit. Therefore, by changing the delay degree in the delay process, the decompression unit can be controlled according to various operating conditions. As a result, according to the refrigeration cycle device of the first embodiment of the present invention, it is possible to achieve appropriate control of the decompression unit according to the operating conditions.

[0015] In addition, the refrigeration cycle device of the second embodiment of the present invention includes a branch part, a first pressure reducing part, a first evaporation part, a second pressure reducing part, a second evaporation part, a pressure reducing control part, a first pressure detecting part, a second pressure detecting part, a first temperature detecting part and a second temperature detecting part.

[0016] The branching portion branches the flow of the refrigerant. The first decompression portion decompresses the refrigerant on one side flowing out of the branching portion. The first evaporation portion evaporates the refrigerant decompressed by the first decompression portion. The second decompression portion decompresses the refrigerant on the other side flowing out of the branching portion. The second evaporation portion evaporates the refrigerant decompressed by the second decompression portion. The decompression control portion controls the operation of the first decompression portion and the second decompression portion. The first pressure detection portion detects a first outlet side pressure of the refrigerant on the outlet side of the first evaporation portion. The second pressure detection portion detects a second outlet side pressure of the refrigerant on the outlet side of the second evaporation portion. The first temperature detection portion detects a first outlet side temperature of the refrigerant on the outlet side of the first evaporation portion. The second temperature detection portion detects a second outlet side temperature of the refrigerant on the outlet side of the second evaporation portion.

[0017] The pressure reducing control unit controls the first pressure reducing unit using the first outlet side pressure and the first delayed outlet side temperature after the first outlet side temperature has been subjected to the first delay process. The pressure reducing control unit controls the second pressure reducing unit using the second outlet side pressure and the second delayed outlet side temperature after the second delay process has been subjected to the second delay process. Further, the pressure reducing control unit can set the delay degree in the first delay process and the delay degree in the second delay process to different degrees.

[0018] Thus, similar to the refrigeration cycle device of the first embodiment, by changing the delay degree in the first delay process and the delay degree in the second delay process, the first pressure reducing unit and the second pressure reducing unit can be controlled according to various operating conditions. At this time, the delay degree in the first delay process and the delay degree in the second delay process can be set to different degrees, so that the first pressure reducing unit and the second pressure reducing unit can be appropriately controlled.

[0019] A refrigeration cycle device according to a third aspect of the present invention includes an evaporating section, a downstream pressure reducing section, a pressure reducing control section, a pressure detecting section, and a temperature detecting section.

[0020] The evaporation section evaporates the refrigerant. The downstream pressure reducing section reduces the pressure of the refrigerant flowing out of the evaporation section. The pressure reducing control section controls the operation of the downstream pressure reducing section. The pressure detecting section detects the outlet pressure of the refrigerant at the outlet of the evaporation section. The temperature detecting section detects the outlet temperature of the refrigerant at the outlet of the evaporation section.

[0021] The pressure reducing control unit controls the pressure reducing unit using the outlet side pressure and the delayed outlet side temperature obtained by delaying the outlet side temperature.

[0022] Thus, similar to the refrigeration cycle device of the first aspect, by changing the delay degree in the delay process, the decompression unit can be controlled according to various operating conditions. As a result, according to the refrigeration cycle device of the third aspect of the present invention, appropriate control of the decompression unit can be achieved according to the operating conditions.

[0023] Here, each outlet temperature is not limited to the actual measured value detected by each temperature detection unit, but includes processed values ​​such as noise removal processing to improve the control stability in the pressure reduction control unit. The same applies to each outlet pressure.

[0024] Furthermore, as the noise removal process, a control process equivalent to the delay process may be adopted. In this case, the degree of delay in the delay process is greater than the degree of delay in the noise removal process.

[0025] In addition, the physical quantity detected by each pressure detection unit is not limited to each outlet side pressure, and may be a physical quantity related to each outlet side pressure as long as each outlet side pressure can be detected. The same applies to each temperature detection unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above-mentioned object and other objects, features and advantages of the present invention will become more apparent with reference to the accompanying drawings and the following detailed description.

[0027] Figure 1 It is a schematic overall configuration diagram of the refrigeration cycle device according to the first embodiment.

[0028] Figure 2 This is a control characteristic diagram for determining a time constant of the refrigeration cycle device according to the first embodiment.

[0029] Figure 3 This is an explanatory diagram for explaining a control mode of the electric expansion valve in the refrigeration cycle device according to the first embodiment.

[0030] Figure 4 This is a control characteristic diagram for determining the throttle opening degree of the electric expansion valve in the absolute value control of the refrigeration cycle device according to the first embodiment.

[0031] Figure 5 It is a schematic overall configuration diagram of a refrigeration cycle device according to a second embodiment.

[0032] Figure 6 It is a schematic overall configuration diagram of a refrigeration cycle device according to a third embodiment.

[0033] Figure 7 It is a schematic overall configuration diagram of a refrigeration cycle device according to a fourth embodiment.

[0034] Figure 8 It is a schematic overall configuration diagram of a refrigeration cycle device according to a fifth embodiment.

[0035] Fig. 9 It is a Mollier diagram showing the change in the state of the refrigerant in the refrigeration cycle device according to the fifth embodiment. DETAILED DESCRIPTION

[0036] Hereinafter, a plurality of embodiments for implementing the present invention will be described with reference to the accompanying drawings. In each embodiment, sometimes the same reference numerals are given to portions corresponding to matters described in a previous embodiment, and repeated descriptions are omitted. In the case where only a part of the configuration is described in each embodiment, other embodiments described previously can be applied to other parts of the configuration. In each embodiment, not only is it clearly indicated that the parts that can be specifically combined are combined with each other, but also, as long as there is no particular obstacle to the combination, even if it is not clearly indicated, the embodiments can be partially combined with each other.

[0037] (First Embodiment)

[0038] use Figure 1 to Figure 4 A first embodiment of the refrigeration cycle device 1 of the present invention is described. In this embodiment, the refrigeration cycle device 1 of the present invention is applied to a vehicle air conditioning device. The vehicle air conditioning device performs air conditioning in a vehicle interior as an air conditioning target space. In the vehicle air conditioning device, the refrigeration cycle device 1 performs temperature control of the supply air blown into the vehicle interior.

[0039] like Figure 1 As shown, the refrigeration cycle device 1 includes a compressor 11, a condenser 12, a receiver 13, an electric expansion valve 14, an evaporator 15, a control device 20, and the like.

[0040] The refrigeration cycle device 1 uses an HFO-based refrigerant (specifically, R1234yf) as a refrigerant. The refrigeration cycle device 1 constitutes a vapor compression subcritical refrigeration cycle in which the pressure of the high-pressure side refrigerant does not exceed the critical pressure of the refrigerant. Refrigeration oil for lubricating the compressor 11 is mixed in the refrigerant. The refrigeration oil is a PAG oil that is compatible with the liquid phase refrigerant. A portion of the refrigeration oil circulates in the refrigeration cycle device 1 together with the refrigerant.

[0041] In the refrigeration cycle device 1, the compressor 11 sucks in, compresses, and discharges the refrigerant. The compressor 11 is an electric compressor in which a fixed capacity type compression mechanism with a fixed discharge capacity is driven by an electric motor to rotate. The rotation speed of the compressor 11 (i.e., the refrigerant discharge capacity) is controlled by a control signal output from a control device 20 described later.

[0042] The refrigerant inlet side of the condenser 12 is connected to the discharge port of the compressor 11. The condenser 12 is an outside air heat exchanger that exchanges heat between the refrigerant discharged from the compressor 11 and the outside air blown from the outside air blower 12a. The condenser 12 is a condensation unit that condenses the refrigerant by dissipating the heat of the refrigerant discharged from the compressor 11 to the outside air.

[0043] The outside air blower 12a is an outside air blower unit whose rotation speed (i.e., air supply capacity) is controlled by a control voltage output from the control device 20. The condenser 12 is arranged at the frontmost side of the vehicle outside the vehicle room. Therefore, when the vehicle is running, the running wind (i.e., outside air) flowing in through the grille can contact the condenser 12.

[0044] The inlet side of the receiver 13 is connected to the refrigerant outlet of the condenser 12. The receiver 13 is a gas-liquid separator on the high-pressure side that separates the gas and liquid of the refrigerant flowing out of the condenser 12 and allows the liquid-phase refrigerant to flow out to the downstream side. The receiver 13 is a liquid receiving part that stores the separated liquid-phase refrigerant as the remaining refrigerant in the cycle. The receiver 13 may also be formed integrally with the condenser 12.

[0045] The inlet side of the electric expansion valve 14 is connected to the outlet of the receiver 13. The electric expansion valve 14 is a decompression unit that decompresses the refrigerant flowing out of the receiver 13. The electric expansion valve 14 is an electric variable throttling mechanism having a valve core that changes the throttling opening and an electric actuator that displaces the valve core. As the electric actuator, a stepping motor or a brushless motor can be used. The operation of the electric expansion valve 14 is controlled by a control signal output from the control device 20.

[0046] The refrigerant inlet side of the evaporator 15 is connected to the outlet of the electric expansion valve 14. The evaporator 15 is an indoor heat exchange unit that performs heat exchange between the refrigerant decompressed by the electric expansion valve 14 and the supply air blown from the indoor blower 15a to the air-conditioning target space. The evaporator 15 is an evaporation unit that evaporates the refrigerant decompressed by the electric expansion valve 14 to absorb heat and cool the supply air. The suction port side of the compressor 11 is connected to the refrigerant outlet of the evaporator 15.

[0047] The indoor air blower 15a is an indoor air supply unit whose rotation speed (i.e., air supply capacity) is controlled by a control voltage output from the control device 20. The evaporator 15 and the indoor air blower 15a are arranged in a housing of an indoor air conditioning unit (not shown). The indoor air conditioning unit is an air distribution device that blows the supply air adjusted to an appropriate temperature for air conditioning in the vehicle interior to an appropriate location in the vehicle interior. The indoor air conditioning unit is arranged in the vehicle interior.

[0048] The control device 20 is composed of a well-known microcomputer including a CPU, a ROM, and a RAM, and its peripheral circuits. The control device 20 performs various calculations and processes based on the control program stored in the ROM, and controls the operation of various control target devices connected to the output side. More specifically, the control device 20 controls the operation of the compressor 11, the outdoor air blower 12a, the electric expansion valve 14, and the indoor air blower 15a.

[0049] A control sensor group is connected to the input side of the control device 20. The sensor group includes an outlet pressure sensor 21a, an outlet temperature sensor 21b, and the like.

[0050] The outlet pressure sensor 21a is a pressure detection unit that detects the pressure of the refrigerant on the outlet side of the evaporator 15, that is, the outlet pressure Pe. More specifically, the outlet pressure sensor 21a detects the pressure of the refrigerant flowing out of the evaporator 15. The outlet temperature sensor 21b is a temperature detection unit that detects the temperature of the refrigerant on the outlet side of the evaporator 15, that is, the outlet temperature Te. More specifically, the outlet temperature sensor 21b detects the pipe temperature of the outlet of the evaporator 15.

[0051] Furthermore, in order to improve the stability of control, the control device 20 uses the processed value obtained by removing noise from the detection value detected by each detection unit as the detection value of the sensor group for air conditioning control. For example, as the outlet temperature Te, the processed value obtained by removing noise from the detection value actually detected by the outlet temperature sensor 21b using the moving average method is used.

[0052] The input side of the control device 20 is connected to an operation panel 22 disposed near the instrument panel in the front portion of the vehicle cabin. Various operation switches operated by the occupant are provided on the operation panel 22. Operation signals from the various operation switches are input to the control device 20.

[0053] Here, the control device 20 integrally constitutes a control unit that controls the operation of various control target devices connected to the output side. Therefore, the structure (hardware and software) that controls the operation of each control target device becomes the control unit that controls the operation of each control target device.

[0054] For example, the configuration of the control device 20 that controls the operation of the compressor 11 is the compressor control unit 20a. Also, the configuration of the control device 20 that controls the operation of the electric expansion valve 14 is the pressure reduction control unit 20b.

[0055] In order to properly control the electric expansion valve 14, the decompression control unit 20b of this embodiment can detect the refrigerant state of the refrigerant on the outlet side of the evaporator 15. Specifically, the decompression control unit 20b can detect the superheat SH and delayed superheat SHd of the refrigerant on the outlet side of the evaporator 15 as the refrigerant state.

[0056] In the pressure reducing control unit 20b, the degree of superheat SH is determined based on the outlet pressure Pe detected by the outlet pressure sensor 21a and the outlet temperature Te detected by the outlet temperature sensor 21b, with reference to a control map pre-stored in the control device 20. The control map determines the degree of superheat SH corresponding to the outlet pressure Pe and the outlet temperature Te based on the physical properties of the refrigerant.

[0057] In addition, in the pressure reducing control unit 20b, based on the outlet pressure Pe and the delayed outlet temperature Ted after the outlet temperature Te is delayed, the delayed superheat SHd is determined by referring to the control map. In the present embodiment, a time constant is used as the delay process. The control map determines the superheat SH corresponding to the outlet pressure Pe and the delayed outlet temperature Ted based on the physical properties of the refrigerant.

[0058] Here, the delayed outlet temperature Ted is a value after the detected outlet temperature Te is delayed. That is, the detected value actually detected by the outlet temperature sensor 21b is subjected to noise removal processing and then subjected to delay processing. The delay degree of the delay processing is set to be greater than the delay degree of the noise removal processing. Therefore, the delayed outlet temperature Ted is a value delayed relative to both the outlet pressure Pe and the outlet temperature Te.

[0059] Furthermore, the pressure reducing control unit 20b can store the superheat degree change amount ΔSH and the delayed superheat degree change amount ΔSHd in advance.

[0060] The superheat change amount ΔSH is the change amount of the superheat SH per predetermined reference time. In the present embodiment, as the superheat change amount ΔSH, a value obtained by subtracting the superheat SH determined last time from the superheat SH determined this time by the pressure reducing control unit 20b is used. The delayed superheat change amount ΔSHd is the change amount of the delayed superheat SHd per predetermined reference time. In the present embodiment, as the delayed superheat change amount ΔSHd, a value obtained by subtracting the delayed superheat SHd determined last time from the delayed superheat SHd determined this time by the pressure reducing control unit 20b is used.

[0061] In addition, in the pressure reduction control unit 20b, if Figure 2 As shown in the control characteristic diagram, the time constant increases with the increase of the superheat SH. That is, the delay degree of the delay process increases with the increase of the superheat SH. Figure 2 In the above, the superheat degree Sb (°C) is higher than the superheat degree Sa (°C). Furthermore, the superheat degree Sc (°C) is higher than the superheat degree Sb (°C).

[0062] In addition, in the pressure reducing control unit 20b, when the superheat SH is equal to or less than the reference high superheat KSHh, the time constant is reduced as the superheat change ΔSH decreases. That is, when the superheat SH is equal to or less than the reference high superheat KSHh, the delay degree in the delay process is reduced as the superheat change ΔSH decreases.

[0063] In other words, in the pressure reduction control unit 20b, when the superheat SH is less than the reference high superheat KSHh and the superheat SH determined this time is reduced to be lower than the superheat SH determined last time, the degree of delay in the delay process is reduced as the absolute value of the superheat change amount ΔSH increases. In the present embodiment, the reference high superheat KSHh is set to 8°C.

[0064] Next, the operation of the vehicle air conditioning device of the present embodiment having the above-mentioned structure will be described. The operation control of the vehicle air conditioning device is performed by executing a control program pre-stored in the control device 20. When the start switch (so-called ignition switch) of the vehicle system is turned on, the control program starts when the automatic switch of the operation panel 22 requesting automatic control of the vehicle air conditioning device is turned on.

[0065] In the control program, the detection signal of the sensor group for air conditioning control and the operation signal of the operation panel 22 are read. Then, based on the read detection signal and operation signal, the target temperature of the supply air blown into the vehicle interior, that is, the target blow-out temperature TAO, is calculated. Furthermore, based on the detection signal, the operation signal, the target blow-out temperature TAO, etc., the operation of various control object devices of the refrigeration cycle device 1 is controlled.

[0066] For example, the rotation speed of the compressor 11 is controlled so that the evaporation temperature of the refrigerant in the evaporator 15 approaches the target evaporation temperature. The target evaporation temperature is determined based on the target outlet temperature TAO and with reference to a control map pre-stored in the control device 20. In the control map, the target evaporation temperature is determined so that the target evaporation temperature decreases as the target outlet temperature TAO decreases.

[0067] In addition, based on the target air outlet temperature TAO, the rotation speed of the indoor air blower 15a is determined with reference to a control map pre-stored in the control device 20. In the control map, the air supply volume of the indoor air blower 15a is set to the maximum in the extremely low temperature range (maximum cooling range) and the extremely high temperature range (maximum heating range) of the target air outlet temperature TAO, and the air supply volume is reduced as it approaches the intermediate temperature range.

[0068] In addition, the throttling opening of the electric expansion valve 14 is controlled so that the superheat SH of the refrigerant at the outlet of the evaporator 15 approaches a predetermined target superheat SHO. In this embodiment, the target superheat SHO is set to 10°C. More specifically, in the control program of this embodiment, Figure 3 As shown, the control mode of the electric expansion valve 14 is switched to appropriately adjust the throttling opening of the electric expansion valve 14 .

[0069] The control modes of the electric expansion valve 14 of the present embodiment include absolute value control, differential control, and protection control. Each control mode will be described below.

[0070] (1) Absolute value control

[0071] When the superheat SH is less than a predetermined reference low superheat KSHL or when the absolute value of the superheat change ΔSH is greater than a predetermined reference change KΔSH, absolute value control is selected. In the present embodiment, the reference low superheat KSHL is set to 1°C.

[0072] Here, when the superheat SH is relatively low, the area occupied by the gas-liquid two-phase refrigerant in the evaporator 15 increases, so the possibility of liquid droplets being mixed in the outlet-side refrigerant of the evaporator 15 flowing at a relatively high speed is high. In addition, when the absolute value of the superheat change amount ΔSH is relatively large, high followability is required for the opening control of the electric expansion valve 14. Therefore, under operating conditions where the possibility of liquid droplets being mixed in the outlet-side refrigerant of the evaporator 15 is high and under operating conditions where high followability is required for the opening control of the electric expansion valve 14, absolute value control is easily selected.

[0073] In the absolute value control, the target throttling opening of the electric expansion valve 14 is determined for each control cycle based on the valve opening differential pressure ΔPe with reference to the control map pre-stored in the control device 20. The valve opening differential pressure ΔPe is a value obtained by subtracting the outlet side pressure Pe from the saturated pressure Ped of the refrigerant at the delayed outlet side temperature Ted described above. The pressure reduction control unit 20b outputs a control signal to the electric expansion valve 14 so that it becomes the determined target throttling opening.

[0074] In the control map, the throttling opening of the electric expansion valve 14 is determined so that the superheat SH approaches the target superheat SHO. Figure 4 As shown in the control characteristic diagram of , the throttling opening of the electric expansion valve 14 is determined to increase with the increase of the valve opening differential pressure ΔPe. As the throttling opening determined by the control map, a value that has been experimentally or analytically confirmed to have reached the target superheat SHO can be used.

[0075] The throttling opening determined by the control map of the present embodiment is a value that changes in substantially the same manner as a temperature-type expansion valve. The temperature-type expansion valve is a pressure reducing device composed of a mechanical structure having a temperature-sensing portion and a valve core portion, the temperature-sensing portion having a diaphragm that deforms according to the temperature of the refrigerant at the outlet of the evaporator and the pressure of the refrigerant at the outlet, and the valve core portion is displaced according to the deformation of the diaphragm to change the throttling opening.

[0076] (2) Differential control

[0077] When the degree of superheat SH is higher than a predetermined reference high degree of superheat KSHh and the absolute value of the superheat change amount ΔSH is lower than the reference change amount KΔSH, the differential control is selected.

[0078] Here, when the superheat SH is relatively high and the absolute value of the superheat change ΔSH is relatively small, the operation of the refrigeration cycle device 1 is stable, so there is a low possibility that liquid droplets are mixed in the refrigerant on the outlet side of the evaporator 15. Therefore, when the operating condition is such that there is a low possibility that liquid droplets are mixed in the refrigerant on the outlet side of the evaporator 15, it is easy to select.

[0079] In the differential control, the pressure reducing control unit 20b uses the deviation between the superheat SH and the target superheat SHO, the rate of change of the deviation, and the cumulative value of the deviation to change the throttle opening of the electric expansion valve 14 by a feedback control method so that the superheat SH approaches the target superheat SHO. In other words, in the differential control, the throttle opening of the electric expansion valve 14 is changed by PID control so that the superheat SH approaches the target superheat SHO.

[0080] (3) Protection control

[0081] When the delayed superheat degree SHd is higher than a predetermined upper limit superheat degree SHMAX, the protection control is selected.

[0082] Here, in the refrigeration cycle device 1, the superheat SH or delayed superheat SHd when the absolute value control or the differential control is performed changes roughly within a range lower than the upper limit superheat SHMAX. That is, the upper limit superheat SHMAX is the maximum superheat assumed during the normal operation of the absolute value control or the differential control. Therefore, the upper limit superheat SHMAX is a value higher than the reference high superheat KSHh. In the present embodiment, the upper limit superheat SHMAX is set to 20°C.

[0083] As operating conditions for the delayed superheat SHd to be higher than the predetermined upper limit superheat SHMAX, there are operating conditions such as when the outside temperature is high, the bubbles in the liquid refrigerant are deflected to the periphery of the valve core portion of the electric expansion valve 14, thereby increasing the passage resistance of the electric expansion valve 14.

[0084] In the protection control, the throttle opening is increased by a predetermined amount for each control cycle so that the delayed superheat SHd becomes equal to or less than the upper limit superheat SHMAX, thereby quickly shifting to the absolute value control or the differential control.

[0085] In the control program, the operation of various control target devices of the refrigeration cycle device 1 is controlled as described above. Then, the control routine of reading the detection signal and the operation signal, calculating the target air outlet temperature TAO, and controlling various control target devices is repeated for each predetermined control cycle until the end condition of the control program is met.

[0086] Therefore, in the refrigeration cycle device 1, the refrigerant discharged from the compressor 11 flows into the condenser 12, exchanges heat with the outside air and dissipates heat. The refrigerant condensed by the condenser 12 flows into the receiver 13 and is separated into gas and liquid. The liquid phase refrigerant flowing out of the receiver 13 flows into the electric expansion valve 14 and is decompressed. At this time, the throttling opening of the electric expansion valve 14 is controlled so that the superheat SH of the refrigerant on the outlet side of the evaporator 15 is close to the target superheat SHO.

[0087] The refrigerant decompressed by the electric expansion valve 14 flows into the evaporator 15, exchanges heat with the supply air and evaporates. The supply air is thereby cooled. The superheated gas-phase refrigerant flowing out of the evaporator 15 is sucked into the compressor 11 and compressed again.

[0088] In addition, in the interior air conditioning unit, the supply air cooled by the evaporator 15 is heated again as needed and blown toward an appropriate location in the vehicle interior. Thus, air conditioning in the vehicle interior is achieved.

[0089] Furthermore, in the refrigeration cycle device 1 of the present embodiment, the control method of the electric expansion valve 14 is switched as described above, and therefore the electric expansion valve 14 can be appropriately controlled according to the operating conditions.

[0090] More specifically, in the refrigeration cycle device 1 of the present embodiment, the pressure reduction control unit 20b uses at least the outlet pressure Pe and the delayed outlet temperature Ted to control the operation of the electric expansion valve 14. Therefore, by changing the time constant used in the delay process, control can be performed according to various operating conditions. As a result, according to the refrigeration cycle device 1 of the present embodiment, the electric expansion valve 14 can be appropriately controlled according to the operating conditions.

[0091] For example, if absolute value control is performed at the start of the compressor 11, the decrease in the outlet temperature Ted is delayed relative to the decrease in the outlet pressure Pe, so that the valve opening differential pressure ΔPe can be made higher than when the outlet temperature Te is used. Therefore, the throttling opening of the electric expansion valve 14 can be increased at the start of the compressor 11. That is, the electric expansion valve 14 can be reliably opened at the start of the compressor 11.

[0092] In addition, in the refrigeration cycle device 1 of the present embodiment, if the Figure 2 As described in the control characteristic diagram of , the time constant increases with the increase of the superheat SH of the outlet refrigerant. As a result, the superheat SH of the outlet refrigerant becomes lower, and the time constant can be reduced under the operating conditions where droplets are easily mixed in the actual outlet refrigerant.

[0093] Therefore, in absolute value control, the delayed outlet temperature Ted can be quickly reduced to reduce the valve opening pressure difference ΔPe. That is, under operating conditions where liquid droplets are easily mixed in the actual outlet refrigerant, the throttling opening of the electric expansion valve 14 can be reduced to suppress liquid compression of the compressor 11.

[0094] In addition, in the refrigeration cycle device 1 of the present embodiment, if the Figure 2 As described in the control characteristic diagram of , when the superheat SH of the outlet refrigerant is below the reference high superheat KSHh, the time constant is reduced along with the reduction of the superheat change ΔSH. As a result, the reduction amount of the superheat SH increases, and the time constant can be reduced under the operating conditions where droplets are easily mixed in the actual outlet refrigerant.

[0095] Therefore, the delayed outlet temperature Ted can be rapidly reduced during absolute value control to reduce the valve opening differential pressure ΔPe. That is, under operating conditions where liquid droplets are easily mixed in the actual outlet refrigerant, the throttling opening of the electric expansion valve 14 can be reduced to suppress liquid compression of the compressor 11.

[0096] In addition, in the refrigeration cycle device 1 of the present embodiment, when the superheat SH is higher than the reference high superheat KSHh and the absolute value of the superheat change ΔSH is less than the reference change KΔSH, the control can be switched to differential control. In other words, the control can be switched to differential control under operating conditions where the possibility of droplets being mixed in the refrigerant on the outlet side of the evaporator 15 is low.

[0097] Thus, the superheat degree SH can be brought closer to the target superheat degree SHO with higher accuracy than in the absolute value control. Therefore, in the differential control, the temperature distribution of the supply air in the evaporator 15 can be suppressed, and the refrigerant can exhibit sufficient cooling capacity in the evaporator 15 .

[0098] In addition, in the refrigeration cycle device 1 of the present embodiment, protection control can be performed when the delayed superheat SHd exceeds the predetermined upper limit superheat SHMAX. Thus, even if the bubbles in the liquid-phase refrigerant are biased toward the periphery of the valve core portion of the electric expansion valve 14, the throttle opening can be increased to allow the bubbles to flow. As a result, it is possible to quickly shift to absolute value control or differential control to bring the superheat SH close to the target superheat SHO.

[0099] Here, during the protection control, the absolute value of the superheat change ΔSH is often greater than the reference change KΔSH due to the influence of bubbles in the liquid refrigerant. Therefore, by executing the protection control, when the delayed superheat SHd is less than the upper limit superheat SHMAX, the protection control is often transferred to the absolute value control.

[0100] As described above, in the absolute value control, the target throttle opening is determined based on the valve opening differential pressure ΔPe determined using the delayed outlet temperature Ted. Therefore, using the delayed superheat SHd determined using the delayed outlet temperature Ted to determine whether to perform the protection control is equivalent to continuing the control using the same index (i.e., the delayed outlet temperature Ted), which is effective for improving the stability of the switching control method.

[0101] (Second Embodiment)

[0102] In this embodiment, a refrigeration cycle device 1a is described. The refrigeration cycle device 1a is applied to a dual air conditioning type vehicle air conditioning device. In the dual air conditioning type vehicle air conditioning device, the supply air blown to the front seat side and the supply air blown to the rear seat side can be cooled in different evaporators.

[0103] Therefore, if Figure 5As shown in the overall structure diagram, compared with the refrigeration cycle device 1 described in the first embodiment, the refrigeration cycle device 1a includes a branch portion 16a, a first electric expansion valve 141, a second electric expansion valve 142, a front seat evaporator 151, and a rear seat evaporator 152.

[0104] The branching portion 16a branches the flow of the refrigerant flowing out of the receiver 13. As the branching portion 16a, a three-way joint formed by joining a plurality of pipes or a three-way joint formed by providing a plurality of refrigerant passages in a metal block or a resin block can be adopted.

[0105] The first electric expansion valve 141 is a first decompression unit that decompresses the refrigerant on one side that flows out from the branch portion 16a. The second electric expansion valve 142 is a second decompression unit that decompresses the refrigerant on the other side that flows out from the branch portion 16a. The basic structures of the first electric expansion valve 141 and the second electric expansion valve 142 are the same as those of the electric expansion valve 14 described in the first embodiment.

[0106] The front seat evaporator 151 is an indoor heat exchange unit for the front seat that performs heat exchange between the refrigerant decompressed by the first electrical expansion valve 141 and the supply air blown from the front seat blower 151a to the air-conditioning target space on the front seat side. The front seat blower 151a is a first evaporation unit that evaporates the refrigerant decompressed by the first electrical expansion valve 141 to absorb heat, thereby cooling the supply air blown to the air-conditioning target space on the front seat side.

[0107] The rear seat evaporator 152 is an indoor heat exchange unit for the rear seat that performs heat exchange between the refrigerant decompressed by the second electric expansion valve 142 and the supply air blown from the rear seat blower 152a to the air conditioning target space on the rear seat side. The rear seat blower 152a is a second evaporation unit that evaporates the refrigerant decompressed by the second electric expansion valve 142 to absorb heat, thereby cooling the supply air blown to the air conditioning target space on the rear seat side.

[0108] The basic structure of the front seat evaporator 151 and the rear seat evaporator 152 is the same as that of the evaporator 15 described in the first embodiment. The basic structure of the front seat blower 151a and the rear seat blower 152a is the same as that of the indoor blower 15a described in the first embodiment.

[0109] The inlet side of one side of the confluence portion 16b is connected to the refrigerant outlet of the front seat evaporator 151. The inlet side of the other side of the confluence portion 16b is connected to the refrigerant outlet of the rear seat evaporator 152. The suction port side of the compressor 11 is connected to the outlet of the confluence portion 16b. As the confluence portion 16b, a three-way joint having the same structure as the branch portion 16a can be used. Therefore, in the refrigeration cycle device 1a, the front seat evaporator 151 and the rear seat evaporator 152 are connected in parallel with respect to the refrigerant flow.

[0110] The front seat evaporator 151 and the front seat blower 151a are arranged in a housing of an indoor air conditioning unit for the front seat (not shown). The rear seat evaporator 152 and the rear seat blower 152a are arranged in a housing of an indoor air conditioning unit for the rear seat (not shown). The indoor air conditioning unit for the front seat and the indoor air conditioning unit for the rear seat are the same air distribution devices as the indoor air conditioning unit described in the first embodiment.

[0111] Furthermore, a first outlet pressure sensor 211 a , a first outlet temperature sensor 211 b , a second outlet pressure sensor 212 a , and a second outlet temperature sensor 212 b as a control sensor group are connected to the input side of the control device 20 of the present embodiment.

[0112] The first outlet pressure sensor 211a is a first pressure detector for detecting a first outlet pressure Pe1 of the outlet refrigerant of the front seat evaporator 151. The first outlet temperature sensor 211b is a first temperature detector for detecting a first outlet temperature Te1 of the outlet refrigerant of the front seat evaporator 151.

[0113] The second outlet pressure sensor 212a is a second pressure detector for detecting a second outlet pressure Pe2 of the outlet refrigerant of the rear seat evaporator 152. The second outlet temperature sensor 212b is a second temperature detector for detecting a second outlet temperature Te2 of the outlet refrigerant of the rear seat evaporator 152.

[0114] Furthermore, the pressure reduction control unit 20 b of the present embodiment controls the operations of the first electric expansion valve 141 and the second electric expansion valve 142 .

[0115] Similar to the first embodiment, the decompression control unit 20b of the present embodiment determines the first degree of superheat SH1 of the refrigerant at the outlet side of the front seat evaporator 151 based on the first outlet side pressure Pe1 and the first outlet side temperature Te1. Further, similar to the first embodiment, the decompression control unit 20b determines the first delayed degree of superheat SHd1 based on the first outlet side pressure Pe1 and the first delayed outlet side temperature Ted1 obtained by performing a first delay process on the first outlet side temperature Te1.

[0116] In addition, similarly to the first embodiment, the pressure reduction control unit 20b determines the second superheat degree SH2 of the refrigerant at the outlet side of the rear seat evaporator 152 based on the second outlet side pressure Pe2 and the second outlet side temperature Te2. Further, similarly to the first embodiment, the pressure reduction control unit 20b determines the second delayed superheat degree SHd2 based on the second outlet side pressure Pe2 and the second delayed outlet side temperature Ted2 obtained by performing a second delay process on the second outlet side temperature Te2.

[0117] In addition, the pressure reduction control unit 20b of the present embodiment can set the delay degree in the first delay process and the delay degree in the second delay process to different degrees. The other configurations of the refrigeration cycle device 1a are the same as those of the refrigeration cycle device 1 described in the first embodiment.

[0118] Next, the operation of the present embodiment in the above-mentioned structure is described. In the control procedure of the present embodiment, the throttling opening of the first electric expansion valve 141 is controlled so that the first superheat SH1 of the refrigerant on the outlet side of the front seat evaporator 151 approaches the first target superheat SHO1. Then, the control mode of the first electric expansion valve 141 is switched in the same manner as in the first embodiment.

[0119] The throttle opening of the second electric expansion valve 142 is controlled so that the second superheat SH2 of the refrigerant at the outlet of the rear seat evaporator 152 approaches the second target superheat SHO2. Then, the control mode of the second electric expansion valve 142 is switched similarly to the first embodiment.

[0120] Here, in the refrigeration cycle device 1a, the refrigerant outlet of the front seat evaporator 151 and the refrigerant outlet of the rear seat evaporator 152 communicate via the junction 16b. Therefore, the refrigerant evaporation temperature in the front seat evaporator 151 and the refrigerant evaporation temperature in the rear seat evaporator 152 are substantially the same.

[0121] In contrast, by changing the first superheat SH1 of the refrigerant at the outlet of the front seat evaporator 151 and the second superheat SH2 of the refrigerant at the outlet of the rear seat evaporator 152, the temperatures of the supply air blown to the front seat side and the supply air blown to the rear seat side can be made different.

[0122] Therefore, the pressure reduction control unit 20b of the present embodiment can set the first target superheat degree SHO1 and the second target superheat degree SHO2 to different values ​​according to the operation signal of the operation switch. For example, the target superheat degree of the side with a lower target temperature of the supply air can be set to 10°C, and the target superheat degree of the side with a higher target temperature of the supply air can be set to a value higher than 10°C. The other operations are the same as those of the first embodiment.

[0123] Therefore, in the refrigeration cycle device 1a, the refrigerant discharged from the compressor 11 flows into the condenser 12, exchanges heat with the outside air and dissipates heat. The refrigerant condensed by the condenser 12 flows into the receiver 13 and is separated into gas and liquid. The flow of the liquid phase refrigerant flowing out of the receiver 13 is branched at the branching portion 16a.

[0124] The refrigerant branched at the branching portion 16a flows into the first electric expansion valve 141 and is decompressed. At this time, the throttle opening of the first electric expansion valve 141 is controlled so that the first superheat SH1 of the refrigerant at the outlet of the front seat evaporator 151 approaches the first target superheat SHO1.

[0125] The refrigerant decompressed by the first electric expansion valve 141 flows into the front seat evaporator 151, and evaporates by heat exchange with the supply air blown to the front seat side of the vehicle interior. As a result, the supply air blown to the front seat side is cooled. The gas-phase refrigerant with superheat flowing out of the front seat evaporator 151 flows into the inlet on one side of the confluence portion 16b.

[0126] The other refrigerant branched at the branching portion 16a flows into the second electric expansion valve 142 and is decompressed. At this time, the throttle opening of the second electric expansion valve 142 is controlled so that the second superheat SH2 of the refrigerant at the outlet of the rear seat evaporator 152 approaches the second target superheat SHO2.

[0127] The refrigerant decompressed by the second electric expansion valve 142 flows into the rear seat evaporator 152, and evaporates by heat exchange with the supply air blown to the rear seat side in the vehicle interior. As a result, the supply air blown to the rear seat side is cooled. The gas phase refrigerant with superheat flowing out of the rear seat evaporator 152 flows into the other inlet of the confluence portion 16b. The gas phase refrigerant with superheat confluence at the confluence portion 16b is sucked into the compressor 11 and compressed again.

[0128] In addition, in the front seat interior air conditioning unit, the supply air cooled by the front seat evaporator 151 is blown toward an appropriate position on the front seat side of the vehicle interior. Thus, air conditioning on the front seat side of the vehicle interior is achieved. In addition, in the rear seat interior air conditioning unit, the supply air cooled by the rear seat evaporator 152 is blown toward the rear seat side of the vehicle interior. Thus, air conditioning on the rear seat side of the vehicle interior is achieved.

[0129] Furthermore, in the refrigeration cycle device 1a of the present embodiment, the control method of the first electrical expansion valve 141 and the second electrical expansion valve 142 is switched as in the first embodiment. Therefore, as in the first embodiment, the first electrical expansion valve 141 and the second electrical expansion valve 142 can be appropriately controlled according to the operating conditions.

[0130] At this time, in the refrigeration cycle device 1a, the delay degree in the first delay process and the delay degree in the second delay process can be set to different degrees. Therefore, the first electric expansion valve 141 and the second electric expansion valve 142 can be appropriately controlled.

[0131] Here, in the refrigeration cycle device 1a, the pressure reducing control unit 20b may set the first target superheat degree SHO1 and the second target superheat degree SHO2 to different values. Therefore, the pressure reducing control unit 20b can set the delay degree in the first delay process and the delay degree in the second delay process to different degrees, which is very effective in making the front seat evaporator 151 and the rear seat evaporator 152 respectively exert appropriate cooling capabilities.

[0132] In the present embodiment, an example is described in which the operation of the first electric expansion valve 141 is controlled using the first delayed outlet temperature Ted1 and the operation of the second electric expansion valve 142 is controlled using the second delayed outlet temperature Ted2, but the present invention is not limited thereto.

[0133] For example, the operation of the first electric expansion valve 141 may be controlled using the first delayed outlet temperature Ted1 , and the operation of the second electric expansion valve 142 may be controlled without using the second delayed outlet temperature Ted2 .

[0134] In this case, the first electric expansion valve 141 corresponds to the pressure reducing unit described in the first embodiment, and the front seat evaporator 151 corresponds to the evaporating unit described in the first embodiment. Furthermore, the first outlet side pressure sensor 211a corresponds to the pressure detecting unit described in the first embodiment, and the first outlet side temperature sensor 211b corresponds to the pressure detecting unit described in the first embodiment.

[0135] Alternatively, the operation of the second electric expansion valve 142 may be controlled using the second delayed outlet temperature Ted2 , and the operation of the first electric expansion valve 141 may be controlled without using the first delayed outlet temperature Ted1 .

[0136] In this case, the second electric expansion valve 142 corresponds to the pressure reducing unit described in the first embodiment, and the rear seat evaporator 152 corresponds to the evaporating unit described in the first embodiment. Furthermore, the second outlet side pressure sensor 212a corresponds to the pressure detecting unit described in the first embodiment, and the second outlet side temperature sensor 212b corresponds to the pressure detecting unit described in the first embodiment.

[0137] (Third Embodiment)

[0138] In this embodiment, a refrigeration cycle device 1b will be described. The refrigeration cycle device 1b is applied to a vehicle air conditioner. The refrigeration cycle device 1b configures a gas injection cycle of an internal heat exchange system.

[0139] Therefore, if Figure 6 As shown in the overall structure diagram, compared with the refrigeration cycle device 1 described in the first embodiment, the refrigeration cycle device 1b has a branch portion 16a, a first electric expansion valve 141, a second electric expansion valve 142, a compressor 111 and an internal heat exchanger 17 similar to the second embodiment.

[0140] The compressor 111 is a two-stage boost type electric compressor in which a common electric motor drives a low-stage compression mechanism and a high-stage compression mechanism with fixed discharge capacities to rotate. The speed of the compressor 111 (ie, the refrigerant discharge capacity) is controlled by a control signal output from the control device 20 .

[0141] The compressor 111 has a casing that accommodates a low-pressure side compression mechanism, a high-pressure side compression mechanism, an electric motor, etc. A low-pressure suction port, an intermediate-pressure suction port, and a discharge port are formed in the casing.

[0142] The low-pressure suction port is an opening hole for sucking low-pressure refrigerant from the outside of the shell into the low-stage compression mechanism. The intermediate-pressure suction port is an opening hole for allowing the intermediate-pressure refrigerant to flow from the outside of the shell into the inside and merge with the refrigerant in the compression process from low pressure to high pressure. The intermediate-pressure suction port is connected to both the discharge port side of the low-stage compression mechanism and the suction port side of the high-stage compression mechanism inside the shell. The discharge port is an opening hole for discharging the high-pressure refrigerant discharged from the high-stage compression mechanism to the outside of the shell. The refrigerant inlet side of the condenser 12 is connected to the discharge port.

[0143] The first electrical expansion valve 141 is a first pressure reducing unit that reduces the pressure of the refrigerant flowing out of the branch portion 16a. The inlet side of the intermediate pressure passage of the internal heat exchanger 17 is connected to the outlet of the first electrical expansion valve 141. The inlet side of the high pressure passage of the internal heat exchanger 17 is connected to the other outlet of the branch portion 16a.

[0144] The internal heat exchanger 17 is an internal heat exchange unit that exchanges heat between the intermediate-pressure refrigerant flowing through the intermediate-pressure passage and the high-pressure refrigerant flowing through the high-pressure passage. The intermediate-pressure passage is a refrigerant passage through which the intermediate-pressure refrigerant that has been decompressed by the first electric expansion valve 141 flows. The high-pressure passage is a refrigerant passage through which the other refrigerant flowing out of the branch portion 16a flows.

[0145] Therefore, the internal heat exchanger 17 exchanges heat between the intermediate-pressure refrigerant decompressed by the first electric expansion valve 141 and the refrigerant on the other side flowing out from the branch portion 16a. Furthermore, the internal heat exchanger 17 of the present embodiment is a first evaporation portion that allows the intermediate-pressure refrigerant to absorb heat from the high-pressure refrigerant and evaporate the intermediate-pressure refrigerant.

[0146] The intermediate pressure suction port side of the compressor 111 is connected to the outlet of the intermediate pressure passage of the internal heat exchanger 17. The inlet side of the second electric expansion valve 142 is connected to the outlet of the high pressure passage of the internal heat exchanger 17. Therefore, the second electric expansion valve 142 of this embodiment is a second decompression part that decompresses the other refrigerant flowing out from the branch part 16a.

[0147] The refrigerant inlet side of the evaporator 15 is connected to the outlet of the second electric expansion valve 142. Therefore, the evaporator 15 of the present embodiment is a second evaporation part that evaporates the refrigerant decompressed by the second electric expansion valve 142. The low-pressure suction port side of the compressor 111 is connected to the refrigerant outlet of the evaporator 15. Therefore, in the refrigeration cycle device 1b, the internal heat exchanger 17 and the evaporator 15 are connected in parallel with respect to the refrigerant flow.

[0148] Furthermore, a first outlet pressure sensor 211 a , a first outlet temperature sensor 211 b , a second outlet pressure sensor 212 a , and a second outlet temperature sensor 212 b as a control sensor group are connected to the input side of the control device 20 of the present embodiment.

[0149] The first outlet pressure sensor 211a is a first pressure detector that detects the pressure of the outlet refrigerant of the intermediate pressure passage of the internal heat exchanger 17, that is, the first outlet pressure Pe1. The first outlet temperature sensor 211b is a first temperature detector that detects the temperature of the outlet refrigerant of the intermediate pressure passage of the internal heat exchanger 17, that is, the first outlet temperature Te1.

[0150] The second outlet pressure sensor 212a is a second pressure detector for detecting a second outlet pressure Pe2 of the outlet refrigerant of the evaporator 15. The second outlet temperature sensor 212b is a second temperature detector for detecting a second outlet temperature Te2 of the outlet refrigerant of the evaporator 15.

[0151] Furthermore, the pressure reduction control unit 20 b of the present embodiment controls the operations of the first electric expansion valve 141 and the second electric expansion valve 142 .

[0152] The decompression control unit 20b of this embodiment determines the first superheat degree SH1, the first delayed superheat degree SHd1, the second superheat degree SH2, and the second delayed superheat degree SHd2 in the same manner as in the second embodiment. In addition, the decompression control unit 20b can set the delay degree in the first delay process and the delay degree in the second delay process to different degrees. The structure of the other refrigeration cycle device 1b is the same as the refrigeration cycle device 1 described in the first embodiment.

[0153] Next, the operation of the present embodiment in the above-mentioned structure is described. In the control procedure of the present embodiment, the throttling opening of the first electric expansion valve 141 is controlled so that the first superheat SH1 of the refrigerant on the outlet side of the intermediate pressure passage of the internal heat exchanger 17 approaches the first target superheat SHO1. Then, the control mode of the first electric expansion valve 141 is switched in the same manner as in the first embodiment.

[0154] The throttle opening of the second electric expansion valve 142 is controlled so that the second superheat SH2 of the refrigerant at the outlet of the evaporator 15 as the second evaporation section approaches the second target superheat SHO2. Then, the control mode of the second electric expansion valve 142 is switched similarly to the first embodiment.

[0155] In the pressure reduction control unit 20b of the present embodiment, the first target degree of superheat SHO1 and the second target degree of superheat SHO2 can be set to different values, similarly to the second embodiment. The other operations are the same as those of the first embodiment.

[0156] Therefore, in the refrigeration cycle device 1b, the refrigerant discharged from the discharge port of the compressor 111 flows into the condenser 12, exchanges heat with the outside air and dissipates heat. The refrigerant condensed by the condenser 12 flows into the receiver 13 and is separated into gas and liquid. The flow of the liquid phase refrigerant flowing out of the receiver 13 is branched at the branching portion 16a.

[0157] The refrigerant branched at the branching portion 16a flows into the first electric expansion valve 141 and is decompressed. At this time, the throttle opening of the first electric expansion valve 141 is controlled so that the first superheat SH1 of the refrigerant at the outlet side of the intermediate pressure passage of the internal heat exchanger 17 approaches the first target superheat SHO1.

[0158] The refrigerant decompressed by the first electric expansion valve 141 flows into the intermediate pressure passage of the internal heat exchanger 17, and exchanges heat with the high pressure refrigerant flowing in the high pressure passage. As a result, the intermediate pressure refrigerant flowing in the intermediate pressure passage evaporates, and the high pressure refrigerant flowing in the high pressure passage reduces its enthalpy. The gas phase refrigerant with superheat flowing out of the intermediate pressure passage of the internal heat exchanger 17 is sucked into the intermediate pressure suction port of the compressor 111 and compressed again.

[0159] The refrigerant flowing out of the high-pressure passage of the internal heat exchanger 17 flows into the second electric expansion valve 142 and is decompressed. At this time, the throttle opening of the second electric expansion valve 142 is controlled so that the second superheat SH2 of the refrigerant at the outlet of the evaporator 15 approaches the second target superheat SHO2.

[0160] The refrigerant decompressed by the second electric expansion valve 142 flows into the evaporator 15, exchanges heat with the supply air and evaporates. As a result, the supply air is cooled. The superheated gas phase refrigerant flowing out of the evaporator 15 is sucked from the low-pressure suction port of the compressor 111 and compressed again.

[0161] In addition, in the indoor air conditioning unit, similarly to the first embodiment, the supply air cooled by the evaporator 15 is blown toward an appropriate position in the vehicle interior. Thus, air conditioning in the vehicle interior is achieved. In addition, in the refrigeration cycle device 1b of this embodiment, a gas injection cycle of an internal heat exchange method is formed, so that the coefficient of performance (COP) of the cycle can be improved.

[0162] Furthermore, in the refrigeration cycle device 1b of the present embodiment, the control method of the first electrical expansion valve 141 and the second electrical expansion valve 142 is switched as in the first embodiment. Therefore, as in the first embodiment, the first electrical expansion valve 141 and the second electrical expansion valve 142 can be appropriately controlled according to the operating conditions.

[0163] At this time, in the refrigeration cycle device 1b, the delay degree in the first delay process and the delay degree in the second delay process can be set to different degrees, similarly to the second embodiment. Therefore, the first electric expansion valve 141 and the second electric expansion valve 142 can be appropriately controlled.

[0164] In the present embodiment, an example is described in which the operation of the first electric expansion valve 141 is controlled using the first delayed outlet temperature Ted1 and the operation of the second electric expansion valve 142 is controlled using the second delayed outlet temperature Ted2 , but the present invention is not limited thereto.

[0165] For example, as described in the second embodiment, the operation of the first electric expansion valve 141 may be controlled using the first delayed outlet temperature Ted1 , and the operation of the second electric expansion valve 142 may be controlled without using the second delayed outlet temperature Ted2 .

[0166] In this case, the first electrical expansion valve 141 corresponds to the pressure reducing unit described in the first embodiment, and the internal heat exchanger 17 corresponds to the evaporating unit described in the first embodiment. Furthermore, the first outlet side pressure sensor 211a corresponds to the pressure detecting unit described in the first embodiment, and the first outlet side temperature sensor 211b corresponds to the pressure detecting unit described in the first embodiment.

[0167] Alternatively, the operation of the second electric expansion valve 142 may be controlled using the second delayed outlet temperature Ted2 , and the operation of the first electric expansion valve 141 may be controlled without using the first delayed outlet temperature Ted1 .

[0168] In this case, the second electric expansion valve 142 corresponds to the pressure reducing unit described in the first embodiment, and the evaporator 15 corresponds to the evaporating unit described in the first embodiment. Furthermore, the second outlet side pressure sensor 212a corresponds to the pressure detecting unit described in the first embodiment, and the second outlet side temperature sensor 212b corresponds to the pressure detecting unit described in the first embodiment.

[0169] (Fourth Embodiment)

[0170] In this embodiment, a refrigeration cycle device 1c will be described. The refrigeration cycle device 1c is applied to a vehicle air conditioning device. The refrigeration cycle device 1c configures a gas injection cycle of a gas-liquid separation system.

[0171] Therefore, if Figure 7 As shown in the overall structure diagram, compared with the refrigeration cycle device 1 described in the first embodiment, the refrigeration cycle device 1c has the same compressor 111, the first electric expansion valve 141, the second electric expansion valve 142 and the intermediate pressure receiver 13a as the third embodiment.

[0172] In the refrigeration cycle device 1c, the inlet side of the first electric expansion valve 141 similar to the second embodiment is connected to the refrigerant outlet of the condenser 12. The inlet side of the intermediate pressure receiver 13a is connected to the outlet of the first electric expansion valve 141.

[0173] The intermediate pressure receiver 13a is a gas-liquid separator on the intermediate pressure side that separates the intermediate pressure refrigerant that has been decompressed by the first electric expansion valve 141 into gas and liquid. The intermediate pressure receiver 13a is a liquid receiving portion on the intermediate pressure side that stores the separated liquid-phase refrigerant as the remaining refrigerant in the cycle. The intermediate pressure receiver 13a has a gas-phase refrigerant outflow port through which the separated gas-phase refrigerant flows out and a liquid-phase refrigerant outflow port through which the separated liquid-phase refrigerant flows out.

[0174] The intermediate pressure suction port side of the compressor 111 is connected to the gas phase refrigerant outflow port of the intermediate pressure receiver 13a. The inlet side of the second electric expansion valve 142 is connected to the liquid phase refrigerant outflow port of the intermediate pressure receiver 13a. The second electric expansion valve 142 of this embodiment is a decompression unit that decompresses the liquid phase refrigerant flowing out of the intermediate pressure receiver 13a.

[0175] The refrigerant inlet side of the evaporator 15 is connected to the outlet of the second electric expansion valve 142. Therefore, the evaporator 15 of this embodiment is an evaporation part that evaporates the refrigerant decompressed by the second electric expansion valve 142. The low-pressure suction port side of the compressor 111 is connected to the refrigerant outlet of the evaporator 15.

[0176] In addition, a condenser outlet pressure sensor 213a and a condenser outlet temperature sensor 213b as a sensor group for control are connected to the input side of the control device 20 of this embodiment. The condenser outlet pressure sensor 213a is a high-pressure pressure detection unit that detects the high-pressure pressure P1 of the refrigerant flowing out of the condenser 12. The condenser outlet temperature sensor 213b is a high-pressure temperature detection unit that detects the high-pressure temperature T1 of the refrigerant flowing out of the condenser 12. The structure of the other refrigeration cycle device 1c is the same as that of the refrigeration cycle device 1 described in the first embodiment.

[0177] Next, the operation of the present embodiment in the above-described configuration will be described. In the control routine of the present embodiment, the throttle opening of the first electric expansion valve 141 is controlled so that the condenser outlet subcooling degree SC1 approaches the target outlet subcooling degree SCO.

[0178] The condenser outlet subcooling degree SC1 is the subcooling degree of the refrigerant flowing out of the condenser 12. The condenser outlet subcooling degree SC1 can be determined using the high pressure P1 and the high pressure temperature T1. The target outlet subcooling degree SCO is determined with reference to a control map pre-stored in the control device 20 so that the coefficient of performance (COP) of the cycle approaches a maximum value.

[0179] In addition, similarly to the first embodiment, the throttle opening of the second electric expansion valve 142 is controlled so that the superheat SH approaches the target superheat SHO. Then, similarly to the first embodiment, the control mode of the second electric expansion valve 142 is switched. The other operations are the same as those of the first embodiment.

[0180] Therefore, in the refrigeration cycle device 1c, the refrigerant discharged from the discharge port of the compressor 111 flows into the condenser 12, exchanges heat with the outside air and dissipates heat. The refrigerant condensed by the condenser 12 flows into the first electric expansion valve 141 and is decompressed. At this time, the throttling opening of the first electric expansion valve 141 is controlled so that the condenser outlet subcooling degree SC1 is close to the target outlet subcooling degree SCO.

[0181] The refrigerant decompressed by the first electric expansion valve 141 flows into the intermediate pressure receiver 13a to be separated into gas and liquid. The gas-phase refrigerant flowing out of the gas-phase refrigerant outflow port of the intermediate pressure receiver 13a is sucked into the intermediate pressure suction port of the compressor 111 to be compressed again.

[0182] The liquid refrigerant flowing out of the liquid refrigerant outlet of the intermediate pressure receiver 13a flows into the second electric expansion valve 142 and is decompressed. At this time, the throttle opening of the second electric expansion valve 142 is controlled so that the superheat SH of the refrigerant at the outlet of the evaporator 15 approaches the target superheat SHO.

[0183] The refrigerant decompressed by the second electric expansion valve 142 flows into the evaporator 15, exchanges heat with the supply air and evaporates. As a result, the supply air is cooled. The superheated gas phase refrigerant flowing out of the evaporator 15 is sucked from the low-pressure suction port of the compressor 111 and compressed again.

[0184] In addition, in the indoor air conditioning unit, similarly to the first embodiment, the supply air cooled by the evaporator 15 is blown toward an appropriate portion of the vehicle interior. Thus, air conditioning in the vehicle interior is achieved. In addition, in the refrigeration cycle device 1c of this embodiment, since a gas injection cycle of a gas-liquid separation method is constituted, the coefficient of performance (COP) of the cycle can be improved.

[0185] Furthermore, in the refrigeration cycle device 1c of the present embodiment, the control method of the second electric expansion valve 142 is switched similarly to the first embodiment. Therefore, similarly to the first embodiment, the second electric expansion valve 142 can be appropriately controlled according to the operating conditions.

[0186] (Fifth Embodiment)

[0187] In this embodiment, a refrigeration cycle device 1d is described. The refrigeration cycle device 1d is applied to a vehicle air conditioning device with a vehicle-mounted device temperature adjustment function. In the vehicle air conditioning device with a vehicle-mounted device temperature adjustment function, not only air conditioning in the vehicle cabin can be performed, but also the temperature of the vehicle-mounted device can be adjusted. In the vehicle air conditioning device of this embodiment, the temperature of the battery 30 as the vehicle-mounted device is adjusted.

[0188] The battery 30 is a secondary battery that stores power to be supplied to a plurality of onboard devices that operate on electricity. The battery 30 is a battery pack formed by connecting a plurality of stacked battery cells electrically in series or in parallel and accommodating them in a dedicated housing. More specifically, the battery cells of this embodiment are lithium-ion batteries.

[0189] The battery 30 generates heat when it is in operation (i.e., when it is charged or discharged). The output of the battery 30 is likely to decrease at low temperatures, and it is likely to deteriorate at high temperatures. Therefore, in the vehicle air conditioning device of this embodiment, when the temperature of the battery 30 rises, the cooling capacity of the refrigeration cycle device 1d is used to cool the battery 30.

[0190] Therefore, if Figure 8 As shown in the overall configuration diagram of , compared to the refrigeration cycle device 1a described in the second embodiment, the refrigeration cycle device 1d includes a battery cooling heat exchanger 153 and a third electric expansion valve 143.

[0191] In the refrigeration cycle device 1d, the inlet side of the battery cooling heat exchanger 153 is connected to the outlet side of the first electrical expansion valve 141. The battery cooling heat exchanger 153 has a refrigerant passage through which the refrigerant decompressed by the first electrical expansion valve 141 flows. The battery cooling heat exchanger 153 is formed integrally with a dedicated housing of the battery 30, and can achieve heat transfer between the refrigerant flowing through the refrigerant passage and the battery 30.

[0192] Therefore, the battery cooling heat exchanger 153 of the present embodiment is a battery heat exchange unit that exchanges heat between the refrigerant decompressed by the first electrical expansion valve 141 and the battery 30. The battery cooling heat exchanger 153 is an evaporation unit that cools the battery 30 by evaporating the refrigerant decompressed by the first electrical expansion valve 141 to absorb heat.

[0193] The inlet side of the third electric expansion valve 143 is connected to the outlet of the refrigerant passage of the battery cooling heat exchanger 153. The basic structure of the third electric expansion valve 143 is the same as that of the electric expansion valve 14 described in the first embodiment. The outlet of the third electric expansion valve 143 is connected to the inlet side of one side of the confluence portion 16b.

[0194] In addition, the refrigerant inlet side of the evaporator 15 is connected to the outlet side of the second electric expansion valve 142. The other inlet side of the junction 16b is connected to the refrigerant outlet of the evaporator 15. Therefore, in the refrigeration cycle device 1d, the battery cooling heat exchanger 153 and the evaporator 15 are connected in parallel with respect to the refrigerant flow.

[0195] Therefore, the first electric expansion valve 141 of the present embodiment is an upstream pressure reducing unit that reduces the pressure of the refrigerant branched from the branching portion 16a and flows out to the inlet side of the battery cooling heat exchanger 153. The third electric expansion valve 143 is a downstream pressure reducing unit that reduces the pressure of the refrigerant flowing out of the battery cooling heat exchanger 153.

[0196] The second electric expansion valve 142 of this embodiment is an auxiliary decompression unit that decompresses the other refrigerant branched from the branching portion 16a. The evaporation unit 15 of this embodiment is an auxiliary evaporation unit that evaporates the refrigerant decompressed by the second electric expansion valve 142.

[0197] Furthermore, a first outlet pressure sensor 211 a , a first outlet temperature sensor 211 b , a second outlet pressure sensor 212 a , and a second outlet temperature sensor 212 b as a control sensor group are connected to the input side of the control device 20 of the present embodiment.

[0198] The first outlet pressure sensor 211a is a pressure detection unit that detects the pressure of the refrigerant at the outlet of the battery cooling heat exchanger 153 and the refrigerant on the upstream side of the third electric expansion valve 143, that is, the first outlet pressure Pe1. The first outlet temperature sensor 211b is a temperature detection unit that detects the temperature of the refrigerant at the outlet of the battery cooling heat exchanger 153 and the refrigerant on the upstream side of the third electric expansion valve 143, that is, the first outlet temperature Te1.

[0199] The second outlet pressure sensor 212a is an auxiliary pressure detector for detecting the second outlet pressure Pe2 of the outlet refrigerant of the evaporator 15. The second outlet temperature sensor 212b is an auxiliary temperature detector for detecting the second outlet temperature Te2 of the outlet refrigerant of the evaporator 15.

[0200] In addition, the pressure reducing control unit 20b of the present embodiment controls the operation of the first electrical expansion valve 141, the second electrical expansion valve 142, and the third electrical expansion valve 143. The pressure reducing control unit 20b of the present embodiment determines the first superheat SH1, the first delayed superheat SHd1, the second superheat SH2, etc., in the same manner as in the second embodiment. The structure of the other refrigeration cycle device 1d is the same as that of the refrigeration cycle device 1a described in the second embodiment.

[0201] Next, the operation of the present embodiment in the above-mentioned structure is described. In the control routine of the present embodiment, the throttling opening of the first electric expansion valve 141 is controlled so that the first outlet side pressure Pe1 of the refrigerant at the outlet side of the battery cooling heat exchanger 153 approaches the predetermined battery target pressure PBO. The battery target pressure PBO is determined so that the battery 30 can be appropriately cooled by the battery cooling heat exchanger 153.

[0202] In addition, the throttling opening of the third electric expansion valve 143 is controlled so that the first superheat SH1 of the refrigerant at the outlet side of the battery cooling heat exchanger 153 approaches a predetermined first target superheat SHO1. In the present embodiment, the first target superheat SHO1 is set to 1° C. Then, the control mode of the third electric expansion valve 143 is switched in the same manner as in the first embodiment.

[0203] The throttle opening of the second electric expansion valve 142 is controlled so that the second superheat SH2 of the refrigerant at the outlet of the evaporator 15 approaches the second target superheat SHO2 determined by the pressure reduction control unit 20b. The other operations are the same as those of the second embodiment.

[0204] Therefore, in the refrigeration cycle device 1d, if Fig. 9 As shown in the Mollier diagram, the state of the refrigerant changes. The refrigerant discharged from the compressor 11 ( Fig. 9 a9 point) flows into the condenser 12, exchanges heat with the outside air and dissipates heat (from Fig. 9 The refrigerant condensed by the condenser 12 enters the receiver 13 and is separated into gas and liquid. The flow of the liquid phase refrigerant flowing out of the receiver 13 is branched at the branching portion 16a.

[0205] The refrigerant branched off at the branching portion 16a flows into the first electric expansion valve 141 and is decompressed ( Fig. 9 At this time, the throttling opening of the first electric expansion valve 141 is controlled so that the outlet side refrigerant ( Fig. 9 The first outlet side pressure Pe1 (at point d9) is close to the battery target pressure PBO.

[0206] The refrigerant decompressed by the first electrical expansion valve 141 flows into the battery cooling heat exchanger 153, exchanges heat with the battery 30, and evaporates (from Fig. 9 Thus, the battery 30 is cooled.

[0207] The refrigerant flowing out of the battery cooling heat exchanger 153 flows into the third electric expansion valve 143 and is decompressed (from Fig. 9 At this time, the throttling opening of the third electric expansion valve 143 is controlled so that the outlet side refrigerant ( Fig. 9 The first superheat degree SH1 (at point d9) approaches the first target superheat degree SHO1. The refrigerant decompressed by the third electric expansion valve 143 flows into one inlet of the merging portion 16b.

[0208] The other refrigerant branched off at the branch portion 16a flows into the second electric expansion valve 142 and is decompressed (from Fig. 9At this time, the throttle opening of the second electric expansion valve 142 is controlled so that the second superheat degree SH2 of the refrigerant on the outlet side of the evaporator 15 approaches the second target superheat degree SHO2.

[0209] The refrigerant decompressed by the second electric expansion valve 142 flows into the evaporator 15, exchanges heat with the supply air and evaporates (from Fig. 9 The refrigerant flowing out of the evaporator 15 flows into the other inlet of the junction 16b. The refrigerant flowing out of the junction 16b is sucked into the compressor 11 and compressed again (from Fig. 9 from e9 to a9).

[0210] As described above, according to the vehicle air conditioning device of the present embodiment, it is possible to realize air conditioning in the vehicle interior and to cool the battery 30 .

[0211] Furthermore, in the refrigeration cycle device 1d of the present embodiment, the control method of the third electric expansion valve 143 is switched as in the first embodiment, so that the third electric expansion valve 143 can be appropriately controlled according to the operating conditions. That is, even in a cycle structure in which the operation of the third electric expansion valve 143 is controlled in order to adjust the superheat of the refrigerant on the upstream side of the third electric expansion valve 143 as in the present embodiment, the same effect as in the first embodiment can be obtained.

[0212] Here, in the battery cooling heat exchanger 153 of the refrigeration cycle device 1d, the refrigerant is directly heat-exchanged with the battery 30 to cool the battery 30. Therefore, the third electric expansion valve 143 can appropriately adjust the first superheat SH1 of the refrigerant at the outlet side of the battery cooling heat exchanger 153, which is effective in reducing the temperature distribution of the refrigerant in the battery cooling heat exchanger 153 and uniformly cooling the battery 30.

[0213] The refrigeration cycle device 1d of the present embodiment includes a branch portion 16a, a first electric expansion valve 141 as an upstream pressure reducing portion, a second electric expansion valve 142 as an auxiliary pressure reducing portion, an evaporator 15 as an auxiliary evaporation portion, and a confluence portion 16b.

[0214] Thus, the refrigerant evaporation temperature in the battery cooling heat exchanger 153 and the refrigerant evaporation temperature in the evaporator 15 can be set to different temperature zones. Therefore, different cooling targets such as the battery 30 and the supply air in this embodiment can be cooled in different temperature zones without changing the superheat of the refrigerant on the outlet side of the battery cooling heat exchanger 153 and the superheat of the refrigerant on the outlet side of the evaporator 15.

[0215] In addition, in the present embodiment, an example in which the operation of the third electric expansion valve 143 is controlled using the first delayed outlet-side temperature Ted1 has been described, but the present invention is not limited to this.

[0216] For example, the operation of the first electrical expansion valve 141 may be controlled using the first delayed outlet temperature Ted1. In this case, the first electrical expansion valve 141 corresponds to the pressure reducing unit described in the first embodiment, and the battery cooling heat exchanger 153 corresponds to the evaporation unit described in the first embodiment. Then, the throttling opening of the third electrical expansion valve 143 may be controlled so that the first outlet pressure Pe1 of the refrigerant at the outlet of the battery cooling heat exchanger 153 approaches the battery target pressure PBO.

[0217] The present invention is not limited to the above-described embodiment, and various modifications are possible as follows without departing from the gist of the present invention.

[0218] In the above-mentioned embodiment, an example in which the refrigeration cycle device 1 of the present invention is applied to a vehicle air conditioner is described, but the application of the refrigeration cycle device is not limited to a vehicle air conditioner. For example, it can be applied to an air conditioner for stationary use.

[0219] The structure of the refrigeration cycle device of the present invention is not limited to the structure disclosed in the above-mentioned embodiment.

[0220] For example, the compressor 11 is not limited to an electric compressor. For example, an engine-driven compressor driven by a rotational driving force transmitted from an engine may be used. As the engine-driven compressor, a variable capacity compressor that can adjust the refrigerant discharge capacity by changing the discharge capacity may be used.

[0221] In addition, in the above-mentioned embodiment, an example of using the condenser 12 as the condensing unit is described, but it is not limited to this. For example, a water refrigerant heat exchange unit that performs heat exchange between the refrigerant discharged from the compressor 11, 111 and the heat medium may be used as the condensing unit. Furthermore, a heating heat exchange unit that performs heat exchange between the heat medium heated by the water refrigerant heat exchange unit and the heating target fluid may be arranged in the heat medium circuit that circulates the heat medium.

[0222] In addition, in the above-mentioned embodiment, the evaporator 15, 151, 152 is used as an example of the evaporation section, but the present invention is not limited thereto. For example, a water refrigerant heat exchange section that performs heat exchange between the refrigerant decompressed by the decompression section 14, 141, 142 and the heat medium may be used as the evaporation section. Furthermore, a cooling heat exchange section that performs heat exchange between the heat medium cooled by the water refrigerant heat exchange section and the cooling target fluid may be arranged in the heat medium circuit that circulates the heat medium.

[0223] As the heat medium, an ethylene glycol aqueous solution, a solution containing dimethylpolysiloxane or nanofluid, an aqueous liquid refrigerant containing antifreeze, alcohol, or the like, a liquid medium containing oil, or the like can be used.

[0224] In addition, as the condenser 12 and the receiver 13, a so-called subcooling type condenser may be used. The subcooling type condenser includes a condensing section, a receiver section, and a supercooling section. The condensing section, like the condenser 12, condenses the refrigerant by exchanging heat between the refrigerant and the outside air. The receiver section, like the receiver 13, separates the refrigerant flowing out of the condensing section into gas and liquid and stores a part of the separated liquid-phase refrigerant as circulating surplus refrigerant. Supercooling is to supercool the liquid-phase refrigerant flowing out of the receiver section by exchanging heat between the liquid-phase refrigerant and the outside air.

[0225] In addition, in the refrigeration cycle device 1c of the fourth embodiment, an example of using the intermediate pressure receiver 13a is described, but it is also possible to add a receiver 13 similar to the first embodiment to the refrigerant outlet of the condenser 12 in addition to the intermediate pressure receiver 13a. In the case of adding the receiver 13, the throttling opening of the first electric expansion valve 141 can also be controlled so that the pressure of the refrigerant sucked into the intermediate pressure suction port of the compressor 111, that is, the intermediate pressure Pm, approaches the target intermediate pressure PMO.

[0226] In addition, the refrigeration cycle devices 1 to 1 d may be configured to be able to switch the refrigerant circuit in order to execute another operation mode, as long as they can execute the same operation as the above-described embodiment.

[0227] In addition, in the above-mentioned embodiment, an example of using R1234yf as the refrigerant of the refrigeration cycle device 1 is described, but it is not limited to this. For example, R134a, R600a, R410A, R404A, R32, R407C, etc. may also be used. In addition, a mixed refrigerant obtained by mixing a plurality of these refrigerants may also be used. Furthermore, carbon dioxide may also be used as the refrigerant to form a supercritical refrigeration cycle in which the refrigerant pressure on the high-pressure side is higher than the critical pressure of the refrigerant.

[0228] In addition, in the above-mentioned embodiment, the outlet pressure sensor 21a for detecting the outlet pressure Pe is used as an example of the pressure detection unit, but the present invention is not limited thereto. As for the pressure detection unit, as long as it can detect the outlet pressure Pe, a detection unit that can detect a physical quantity related to the outlet pressure Pe may be used.

[0229] For example, as the pressure detection unit, an inlet temperature sensor may be used that detects the temperature of the refrigerant at the inlet side of the evaporator 15, that is, the inlet temperature Tei. In this case, the outlet pressure Pe may be obtained by subtracting a value corresponding to the pressure loss of the refrigerant in the evaporator 15 from the saturated pressure Pei of the refrigerant at the inlet temperature Tei.

[0230] The control method of the refrigeration cycle device of the present invention is not limited to the control method disclosed in the above-mentioned embodiment.

[0231] In the above-mentioned embodiment, the refrigeration cycle device 1 capable of executing absolute value control, differential control and protection control is described as the control mode of the electric expansion valve 14, but it is not necessary to be able to execute all of the above control modes. As long as at least absolute value control can be executed, appropriate control of the pressure reducing unit can be achieved according to various operating conditions.

[0232] Furthermore, in the above-described embodiment, an example in which a time constant is used as the delay process executed by the pressure reduction control unit 20 b is described, but a moving average or a section average may be used as the delay process.

[0233] In addition, in the above-mentioned embodiment, an example of determining the valve opening differential pressure ΔPe using the saturated pressure Ped of the refrigerant at the delayed outlet temperature Ted during absolute value control is described, but the present invention is not limited thereto. For example, the valve opening differential pressure ΔPe may be determined using the saturated pressure Ped of a refrigerant of a different type from the refrigerant circulating in the cycle or the saturated pressure Ped of a mixed refrigerant obtained by mixing a plurality of fluids.

[0234] In addition, in the above-mentioned embodiment, an example is described in which the throttle opening of the electric expansion valve 14 is changed based on the deviation between the superheat SH and the target superheat SHO during the differential control so that the superheat SH approaches the target superheat SHO, but the present invention is not limited thereto. During the differential control, the throttle opening of the electric expansion valve 14 may be changed using the deviation between the delayed superheat SHd and the target superheat SHO so that the delayed superheat SHd approaches the target superheat SHO.

[0235] In the above-mentioned embodiment, the example in which the protection control is executed when the delayed superheat degree SHd is equal to or greater than the upper limit superheat degree SHMAX is described, but the present invention is not limited thereto. The protection control may be executed when the superheat degree SH is equal to or greater than the upper limit superheat degree SHMAX.

[0236] The methods disclosed in the above-mentioned embodiments can be appropriately combined within the scope of implementation. For example, the refrigeration cycle devices 1b to 1d described in the third to fifth embodiments may be configured with a first decompression unit, a second decompression unit, a first evaporation unit, and a second evaporation unit in the same manner as in the second embodiment, and applied to the dual air-conditioning type vehicle air-conditioning device described in the second embodiment. Then, the operation of the first decompression unit and the second decompression unit may be controlled in the same manner as in the second embodiment.

[0237] The features of the refrigeration cycle device disclosed in this specification are as follows.

[0238] (Item 1)

[0239] A refrigeration cycle device, comprising:

[0240] A decompression unit (14) that decompresses the refrigerant;

[0241] an evaporation section (15) for evaporating the refrigerant decompressed by the decompression section;

[0242] A pressure reducing control unit (20b), which controls the operation of the pressure reducing unit;

[0243] a pressure detection unit (21a) for detecting an outlet side pressure (Pe) of the refrigerant at the outlet side of the evaporation unit; and

[0244] a temperature detection unit (21b) for detecting an outlet temperature (Te) of the refrigerant at the outlet of the evaporator,

[0245] The pressure reducing control unit controls the pressure reducing unit using the outlet side pressure (Pe) and a delayed outlet side temperature (Ted) obtained by delaying the outlet side temperature (Te).

[0246] (Item 2)

[0247] A refrigeration cycle device described in Item 1, wherein the pressure reduction control unit uses the outlet side pressure (Pe) and the outlet side temperature (Te) to determine the superheat (SH) of the outlet side refrigerant, and increases the degree of delay in the delay processing as the superheat (SH) increases.

[0248] (Item 3)

[0249] A refrigeration cycle device described in item 1 or 2, wherein the pressure reducing control unit uses the outlet side pressure (Pe) and the outlet side temperature (Te) to determine the superheat (SH) of the outlet side refrigerant, and when the superheat (SH) is below a predetermined reference high superheat (KSHh), the degree of delay in the delay processing is reduced along with a decrease in the superheat change (ΔSH) per predetermined reference time of the superheat (SH).

[0250] (Item 4)

[0251] A refrigeration cycle device recorded in any one of items 1 to 3, wherein the pressure reducing control unit uses the outlet side pressure (Pe) and the delayed outlet side temperature (Ted) to determine the target throttling opening of the pressure reducing unit, and is capable of performing absolute value control in which the operation of the pressure reducing unit is controlled to approach the target throttling opening.

[0252] (Item 5)

[0253] A refrigeration cycle device as recorded in any one of items 1 to 4, wherein the pressure reducing control unit uses the outlet side pressure (Pe) and the outlet side temperature (Te) to determine the superheat (SH) of the outlet side refrigerant, and is capable of performing differential control, in which the operation of the pressure reducing unit is controlled to reduce the difference between the superheat (SH) and a predetermined target superheat (SHO).

[0254] (Item 6)

[0255] The refrigeration cycle device described in the item, wherein the pressure reducing control unit performs the differential control when the superheat (SH) is higher than a predetermined reference high superheat (KSHh) and the absolute value of the superheat change (ΔSH) of the superheat (SH) per predetermined reference time is smaller than a predetermined reference change (KΔSH).

[0256] (Item 7)

[0257] A refrigeration cycle device as recorded in any one of items 1 to 6, wherein the pressure reducing control unit uses the outlet side pressure (Pe) and the delayed outlet side temperature (Ted) to determine the delayed superheat (SHd) of the outlet side refrigerant, and is capable of performing protection control to increase the throttling opening of the pressure reducing unit when the delayed superheat (SHd) is above the upper limit superheat (SHMAX) assumed during normal operation.

[0258] (Item 8)

[0259] A refrigeration cycle device, comprising:

[0260] A branching portion (16a) that branches the flow of the refrigerant;

[0261] a first decompression section (141) for decompressing the refrigerant flowing out of the branch section;

[0262] a first evaporation section (151) for evaporating the refrigerant after the refrigerant is decompressed by the first decompression section;

[0263] a second decompression section (142) for decompressing the other refrigerant flowing out of the branch section;

[0264] a second evaporation section (152) for evaporating the refrigerant decompressed by the second decompression section;

[0265] A pressure reducing control unit (20b), which controls the operation of the first pressure reducing unit and the second pressure reducing unit;

[0266] a first pressure detection unit (211a) for detecting a first outlet side pressure (Pe1) of the refrigerant at the outlet side of the first evaporator;

[0267] a second pressure detection unit (212a) for detecting a second outlet side pressure (Pe2) of the refrigerant at the outlet side of the second evaporation unit;

[0268] a first temperature detecting unit (211b) for detecting a first outlet side temperature (Te1) of the refrigerant at the outlet side of the first evaporator; and

[0269] a second temperature detection unit (212b) for detecting a second outlet side temperature (Te2) of the refrigerant at the outlet side of the second evaporation unit,

[0270] The pressure reducing control unit uses the first outlet side pressure (Pe1) and the first delayed outlet side temperature (Ted1) after the first delay processing of the first outlet side temperature (Te1) to control the first pressure reducing unit, and uses the second outlet side pressure (Pe2) and the second delayed outlet side temperature (Ted2) after the second delay processing of the second outlet side temperature (Te2) to control the second pressure reducing unit. Furthermore, the delay degree in the first delay processing and the delay degree in the second delay processing can be set to different degrees.

[0271] (Item 9)

[0272] A refrigeration cycle device, comprising:

[0273] an evaporation section (153) for evaporating a refrigerant;

[0274] a downstream pressure reducing section (143) for reducing the pressure of the refrigerant flowing out of the evaporation section;

[0275] A pressure reducing control unit (20b) for controlling the operation of the downstream pressure reducing unit;

[0276] a pressure detection unit (211a) for detecting an outlet side pressure (Pe) of the refrigerant at the outlet side of the evaporation unit; and

[0277] a temperature detection unit (211b) for detecting an outlet temperature (Te) of the refrigerant at the outlet of the evaporator,

[0278] The pressure reducing control unit controls the downstream pressure reducing unit using the outlet pressure (Pe) and a delayed outlet temperature (Ted) obtained by delaying the outlet temperature (Te).

[0279] (Item 10)

[0280] The refrigeration cycle device according to item 9, comprising:

[0281] a branching portion (16a) that branches the flow of the refrigerant;

[0282] an upstream pressure reducing section (141) which reduces the pressure of the refrigerant on one side of the branch portion and causes the refrigerant to flow out to the refrigerant inlet side of the evaporation section (153);

[0283] an auxiliary decompression section (142) for decompressing the other refrigerant branched from the branch portion;

[0284] an auxiliary evaporation section (15) for evaporating the refrigerant decompressed by the auxiliary decompression section; and

[0285] A merging portion (16b) merges the flow of the refrigerant flowing out of the evaporation portion and the flow of the refrigerant flowing out of the auxiliary evaporation portion.

[0286] Although the present invention has been described according to the embodiments, it should be understood that the present invention is not limited to the embodiments and structures. The present invention includes various modifications and variations within the equivalent range. In addition, various combinations or forms, even only one element, other combinations or forms above or below one element also belong to the scope or thought range of the present invention.

Claims

1. A refrigeration cycle device, characterized in that: have: A decompression section (14, 142) that decompresses the refrigerant; an evaporation section (15) for evaporating the refrigerant after the refrigerant is decompressed by the decompression section; A pressure reducing control unit (20b), which controls the operation of the pressure reducing unit; a pressure detection unit (21a) for detecting an outlet side pressure (Pe) of the refrigerant at the outlet side of the evaporation unit; and a temperature detection unit (21b) for detecting an outlet temperature (Te) of the refrigerant at the outlet of the evaporator, The pressure reducing control unit controls the pressure reducing unit using the outlet side pressure (Pe) and a delayed outlet side temperature (Ted) obtained by delaying the outlet side temperature (Te).

2. The refrigeration cycle device according to claim 1, characterized in that: The pressure reduction control unit determines a degree of superheat (SH) of the outlet refrigerant using the outlet pressure (Pe) and the outlet temperature (Te), and increases a degree of delay in the delay process as the degree of superheat (SH) increases.

3. The refrigeration cycle device according to claim 1 or 2, characterized in that: The pressure reducing control unit uses the outlet side pressure (Pe) and the outlet side temperature (Te) to determine the superheat (SH) of the outlet side refrigerant. When the superheat (SH) is below a predetermined reference high superheat (KSHh), the degree of delay in the delay processing is reduced along with a decrease in the superheat change (ΔSH) per predetermined reference time of the superheat (SH).

4. The refrigeration cycle device according to claim 1, characterized in that: The pressure reducing control unit determines a target throttle opening of the pressure reducing unit using the outlet side pressure (Pe) and the delayed outlet side temperature (Ted), and is capable of performing absolute value control in which the operation of the pressure reducing unit is controlled to approach the target throttle opening.

5. The refrigeration cycle device according to claim 1, characterized in that: The pressure reducing control unit uses the outlet side pressure (Pe) and the outlet side temperature (Te) to determine the superheat (SH) of the outlet side refrigerant, and is capable of performing differential control, in which the operation of the pressure reducing unit is controlled to reduce the difference between the superheat (SH) and a predetermined target superheat (SHO).

6. The refrigeration cycle device according to claim 5, characterized in that: The pressure reducing control portion performs the differential control when the superheat (SH) is higher than a predetermined reference high superheat (KSHh) and an absolute value of a superheat change (ΔSH) per predetermined reference time of the superheat (SH) is smaller than a predetermined reference change (KΔSH).

7. The refrigeration cycle device according to claim 1, characterized in that: The pressure reducing control unit uses the outlet side pressure (Pe) and the delayed outlet side temperature (Ted) to determine the delayed superheat (SHd) of the outlet side refrigerant, and is capable of performing protection control to increase the throttling opening of the pressure reducing unit when the delayed superheat (SHd) is above the upper limit superheat (SHMAX) assumed during normal operation.

8. A refrigeration cycle device, characterized in that: have: A branching portion (16a) that branches the flow of the refrigerant; a first decompression section (141) for decompressing the refrigerant flowing out of the branch section; a first evaporation section (151) for evaporating the refrigerant after the refrigerant is decompressed by the first decompression section; a second decompression section (142) for decompressing the other refrigerant flowing out of the branch section; a second evaporation section (152) for evaporating the refrigerant decompressed by the second decompression section; A pressure reducing control unit (20b), which controls the operation of the first pressure reducing unit and the second pressure reducing unit; a first pressure detection unit (211a) for detecting a first outlet side pressure (Pe1) of the refrigerant at the outlet side of the first evaporator; a second pressure detection unit (212a) for detecting a second outlet side pressure (Pe2) of the refrigerant at the outlet side of the second evaporation unit; a first temperature detection unit (211b) for detecting a first outlet side temperature (Te1) of the refrigerant at the outlet side of the first evaporation unit; as well as a second temperature detection unit (212b) for detecting a second outlet side temperature (Te2) of the refrigerant at the outlet side of the second evaporation unit, The pressure reducing control unit uses the first outlet side pressure (Pe1) and the first delayed outlet side temperature (Ted1) after the first delay processing of the first outlet side temperature (Te1) to control the first pressure reducing unit, and uses the second outlet side pressure (Pe2) and the second delayed outlet side temperature (Ted2) after the second delay processing of the second outlet side temperature (Te2) to control the second pressure reducing unit. Furthermore, the delay degree in the first delay processing and the delay degree in the second delay processing can be set to different degrees.

9. A refrigeration cycle device, characterized in that: have: an evaporation section (153) for evaporating a refrigerant; a downstream pressure reducing section (143) for reducing the pressure of the refrigerant flowing out of the evaporation section; A pressure reducing control unit (20b) for controlling the operation of the downstream pressure reducing unit; a pressure detection unit (211a) for detecting an outlet side pressure (Pe) of the refrigerant at the outlet side of the evaporation unit; and a temperature detection unit (211b) for detecting an outlet temperature (Te) of the refrigerant at the outlet of the evaporator, The pressure reducing control unit controls the downstream pressure reducing unit using the outlet pressure (Pe) and a delayed outlet temperature (Ted) obtained by delaying the outlet temperature (Te).

10. The refrigeration cycle device according to claim 9, characterized in that: have; A branching portion (16a) that branches the flow of the refrigerant; an upstream pressure reducing section (141) which reduces the pressure of the refrigerant on one side of the branch portion and causes the refrigerant to flow out to the refrigerant inlet side of the evaporation section (153); an auxiliary decompression section (142) for decompressing the other refrigerant branched from the branch portion; an auxiliary evaporation section (15) for evaporating the refrigerant after the refrigerant is decompressed by the auxiliary decompression section; as well as A merging portion (16b) merges the flow of the refrigerant flowing out of the evaporation portion and the flow of the refrigerant flowing out of the auxiliary evaporation portion.

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