JP2023164190A - Refrigeration cycle device - Google Patents

Abstract

To enable determination of reliability of a detection value of a pressure sensor during operation of a compressor.SOLUTION: A refrigeration cycle device comprises: a compressor 11 for sucking, compressing, and discharging refrigerant; a heat radiator 13 for radiating heat of the refrigerant discharged from the compressor; electric expansion valves 14a, 14b and 14c for decompressing and expanding the refrigerant having subjected to heat radiation at the radiator according to an operation current; evaporators 15, 18, 20 for evaporating the refrigerant decompressed and expanded by the electric expansion valves; upstream-side pressure sensors 62a, 62b for detecting a pressure of the refrigerant downstream of the compressor and upstream of the electric expansion valves; downstream-side pressure sensors 62c, 62d, 62e for detecting the pressure of the refrigerant downstream of the electric expansion valves and upstream of the compressor; and a determination unit 60 for estimating a pressure difference of the refrigerant between an inlet and an outlet of the electric expansion valves from the operation currents of the electric expansion valves, and determining a reliability of detection values of the upstream-side pressure sensors and the downstream-side pressure sensors on the basis of the pressure difference of the refrigerant between the inlet and the outlet of the electric expansion valves.SELECTED DRAWING: Figure 1

Description

The present invention relates to a refrigeration cycle device equipped with a pressure sensor.

Conventionally, Patent Document 1 describes a refrigeration cycle device that controls a compressor and a pressure reducer (in other words, an expansion valve) based on information on refrigerant pressure detected by a plurality of pressure sensors.

In this prior art, a high pressure side pressure sensor and a low pressure side pressure sensor are provided as the plurality of pressure sensors. The high pressure side pressure sensor detects the pressure of refrigerant discharged from the compressor. The low pressure side pressure sensor detects the pressure of the refrigerant before being sucked into the compressor.

In this conventional technology, the control device assumes that there is some kind of malfunction if a detected value of a plurality of pressure sensors has a clearly large abnormal difference from other detected values in the steady state of the refrigerant before starting operation. and excluded from the calculation of the detected temperature value.

This steady state is a stable state in which the state of the refrigerant does not fluctuate, and is, for example, the state of the refrigerant when a predetermined period of time, for example, one hour or more has passed since the previous stop of operation of the refrigeration cycle device.

Further, the control device considers a refrigerant pressure sensor in which an abnormal pressure difference is found between the refrigerant pressure sensor and other detected pressure values to be in an abnormal state due to a failure or the like.

In other words, in this conventional technology, when the compressor is stopped and the pressure throughout the cycle is uniform, and the detected values of each pressure sensor are almost the same, the detected values of each pressure sensor Determined to be reliable.

Japanese Patent Application Publication No. 2009-222314

Generally, failure of a pressure sensor in a refrigeration cycle device often occurs during operation of the compressor. Furthermore, the more the compressor is in operation, the greater the impact on other components when the pressure sensor fails. Therefore, reliability determination while the compressor is in operation is required.

However, in the above conventional technology, it is possible to determine whether or not the detection value of each pressure sensor is reliable only when the compressor is stopped. It is not possible to determine whether the value is reliable or not.

As a countermeasure to this problem, multiple systems of pressure sensors may be considered, but this countermeasure is unfavorable in terms of installation and cost.

In view of the above points, the first object of the present invention is to provide a refrigeration cycle device that can determine the reliability of a detected value of a pressure sensor during operation of a compressor.

In the above-mentioned conventional technology, it is necessary to install a plurality of pressure sensors to control the compressor and the expansion valve, which impairs the compatibility of the refrigeration cycle device with being mounted on a vehicle and complicates the control device.

In view of the above points, a second object of the present invention is to reduce the number of pressure sensors in a refrigeration cycle device that is controlled based on the pressure of refrigerant.

In order to achieve the first object, the refrigeration cycle device according to claim 1,
A compressor that sucks in refrigerant, compresses it, and discharges it;
a radiator that radiates heat from the refrigerant discharged from the compressor;
an electric expansion valve that depressurizes and expands refrigerant heat radiated by the radiator according to an operating current;
an evaporator that evaporates refrigerant expanded under reduced pressure by an electric expansion valve;
an upstream pressure sensor that detects the pressure of refrigerant downstream of the compressor and upstream of the electric expansion valve;
a downstream pressure sensor that detects the pressure of refrigerant downstream of the electric expansion valve and upstream of the compressor;
The differential pressure between the refrigerant inlet and outlet of the electric expansion valve is estimated from the operating current of the electric expansion valve, and the upstream pressure sensor and downstream pressure sensor detect the pressure difference based on the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. and a determination unit that determines reliability of the value.

According to this, the reliability of the detected values of the upstream pressure sensor and the downstream pressure sensor is determined based on the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. Reliability can be determined.

In order to achieve the second objective, the refrigeration cycle device according to claim 5,
A compressor that sucks in refrigerant, compresses it, and discharges it;
a radiator that radiates heat from the refrigerant discharged from the compressor;
an electric expansion valve that depressurizes and expands refrigerant heat radiated by the radiator according to an operating current;
an evaporator that evaporates refrigerant expanded under reduced pressure by an electric expansion valve;
The differential pressure between the refrigerant inlet and outlet of the electric expansion valve is estimated from the operating current of the electric expansion valve, and the opening degree of the electric expansion valve and the compressor are determined based on the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. and a control section that controls at least one of the rotational speeds.

According to this, the differential pressure between the refrigerant inlet and outlet of the electric expansion valve can be obtained without using a pressure sensor, so the number of pressure sensors can be reduced in a refrigeration cycle device that is controlled based on the pressure of the refrigerant.

Note that the reference numerals in parentheses of each means described in this column and the claims indicate correspondence with specific means described in the embodiment described later.

FIG. 1 is an overall configuration diagram of a refrigeration cycle device according to a first embodiment. FIG. 1 is a schematic configuration diagram of an indoor air conditioning unit according to a first embodiment. FIG. 2 is a block diagram showing an electric control section of the vehicle air conditioner according to the first embodiment. FIG. 3 is a schematic cross-sectional view of the bypass side flow rate regulating valve of the first embodiment. It is a characteristic diagram used when estimating the differential pressure between the inlet and outlet of an expansion valve based on the power consumption value of an expansion valve. It is a graph showing the relationship between the pressure difference between the inlet and outlet of the expansion valve and the torque applied to the electric actuator of the expansion valve. It is a graph which shows the relationship between the torque of the electric actuator of an expansion valve, and the consumption current. It is an overall block diagram of the refrigeration cycle apparatus of 3rd Embodiment. It is an overall block diagram of the refrigeration cycle apparatus of 4th Embodiment.

(First embodiment)
EMBODIMENT OF THE INVENTION Below, several embodiment for implementing this invention is described with reference to drawings. In each embodiment, parts corresponding to those described in the preceding embodiments may be given the same reference numerals and redundant explanations may be omitted. When only part of the configuration is described in each embodiment, the other embodiments described previously can be applied to other parts of the configuration. It is not only possible to combine parts of each embodiment that specify that the combinations are possible, but also to partially combine parts of the embodiments even if it is not explicitly stated, as long as there is no particular problem with the combination. is also possible.

(First embodiment)
The refrigeration cycle device of this embodiment will be explained using FIGS. 1 to 7. The refrigeration cycle device of this embodiment is applied to a vehicle air conditioner 1 mounted on an electric vehicle. An electric vehicle is a vehicle that obtains driving force for driving from an electric motor. The vehicle air conditioner 1 air-conditions the interior of a vehicle, which is a space to be air-conditioned, and also adjusts the temperature of on-vehicle equipment. Therefore, the vehicle air conditioner 1 can be called an air conditioner with a vehicle-mounted equipment temperature adjustment function, or a vehicle-mounted equipment temperature adjustment device with an air-conditioning function.

Specifically, the vehicle-mounted device whose temperature is adjusted by the vehicle air conditioner 1 is the battery 70. The battery 70 is a secondary battery that stores power to be supplied to a plurality of on-vehicle devices that operate using electricity. The battery 70 is an assembled battery formed by electrically connecting a plurality of stacked battery cells in series or parallel. The battery cell of this embodiment is a lithium ion battery.

The battery 70 generates heat during operation (that is, during charging and discharging). The output of the battery 70 tends to decrease when the temperature becomes low, and the battery 70 tends to deteriorate when the temperature becomes high. Therefore, the temperature of the battery 70 needs to be maintained within an appropriate temperature range (in this embodiment, 15° C. or higher and 55° C. or lower). Therefore, in the electric vehicle of this embodiment, the temperature of the battery 70 is adjusted using the vehicle air conditioner 1. The on-vehicle equipment whose temperature is to be adjusted by the vehicle air conditioner 1 is not limited to the battery 70.

The vehicle air conditioner 1 includes a refrigeration cycle 10 shown in FIG. 1, a high temperature side heat medium circuit 30, a low temperature side heat medium circuit 40, an indoor air conditioning unit 50 shown in FIG. 2, a control device 60 shown in FIG. 3, etc. .

First, the refrigeration cycle 10 will be explained using FIG. 1. The refrigeration cycle 10 is a vapor compression type that adjusts the temperature of the air blown into the vehicle interior, the high temperature heat medium circulating in the high temperature heat medium circuit 30, and the low temperature heat medium circulating in the low temperature heat medium circuit 40. It is a refrigeration cycle.

The refrigeration cycle 10 is configured to be able to switch refrigerant circuits according to various driving modes in order to air condition the vehicle interior and adjust the temperature of the vehicle-mounted equipment. The refrigeration cycle 10 uses an HFO-based refrigerant (specifically, R1234yf) as the refrigerant. The refrigeration cycle 10 constitutes a subcritical refrigeration cycle in which the pressure of the high-pressure side refrigerant does not exceed the critical pressure of the refrigerant.

Refrigerating machine oil for lubricating the compressor 11 is mixed in the refrigerant. Refrigerating machine oil is PAG oil (ie, polyalkylene glycol oil) or POE (ie, polyol ester) that is compatible with the liquid phase refrigerant. A portion of the refrigeration oil is circulated through the refrigeration cycle 10 together with the refrigerant.

The compressor 11 takes in refrigerant in the refrigeration cycle 10, compresses it, and discharges it. The compressor 11 is an electric compressor that uses an electric motor to rotationally drive a fixed capacity type compression mechanism having a fixed discharge capacity. The refrigerant discharge capacity (ie, rotation speed) of the compressor 11 is controlled by a control signal output from the control device 60 .

The compressor 11 is arranged in a drive device compartment formed on the front side of the vehicle compartment. The drive device room forms a space in which at least a portion of equipment (for example, a motor generator serving as an electric motor for driving) used for generating and adjusting driving force for driving the vehicle is arranged.

The discharge port of the compressor 11 is connected to the inlet side of the first three-way joint 12a. The first three-way joint 12a has three inlets and outlets that communicate with each other. As the first three-way joint 12a, a joint formed by joining a plurality of pipes or a joint formed by providing a plurality of refrigerant passages in a metal block or a resin block can be adopted.

The refrigeration cycle 10 includes a second three-way joint 12b to a sixth three-way joint 12f. The basic configuration of the second three-way joint 12b to the sixth three-way joint 12f is the same as that of the first three-way joint 12a. The basic configuration of each of the other three-way joints in this embodiment is also the same as that of the first three-way joint 12a.

These three-way joints split the flow of refrigerant when one of the three inlets and outlets is used as an inlet and the remaining two as outlets. These three-way joints allow the refrigerant flows to merge when two of the three inlets and outlets are used as inlets and the remaining one is used as an outlet.

The first three-way joint 12a is a branching part that branches the flow of the refrigerant discharged from the compressor 11. The inlet side of the refrigerant passage of the water-refrigerant heat exchanger 13 is connected to one outlet of the first three-way joint 12a. One inlet side of the sixth three-way joint 12f is connected to the other outlet of the first three-way joint 12a.

A refrigerant passage leading from the other outlet of the first three-way joint 12a to one inlet of the sixth three-way joint 12f is a bypass passage 21c. A bypass flow rate regulating valve 14d is arranged in the bypass passage 21c.

The bypass flow rate adjustment valve 14d reduces the pressure of the discharged refrigerant flowing out from the other outlet of the first three-way joint 12a (that is, the other discharged refrigerant branched at the first three-way joint 12a) during the hot gas heating mode, etc. This is a bypass expansion valve. The bypass flow rate adjustment valve 14d is a bypass side flow rate adjustment section that adjusts the flow rate (mass flow rate) of the refrigerant flowing through the bypass passage 21c.

As shown in FIG. 4, the bypass flow rate adjustment valve 14d is an electric variable throttle mechanism (in other words, an electric expansion valve) having a valve body 141 and an electric actuator 142. The valve body 141 changes the throttle opening degree of the bypass flow rate adjustment valve 14d. The electric actuator 142 is a drive unit that displaces the valve body 141. The electric actuator 142 is a brushless DC motor having a coil 142a and a rotor 142b.

The bypass flow rate adjustment valve 14d includes a control board 143, a target magnet 144, a Hall IC section 145, a deceleration mechanism 146, a rotation-to-linear conversion mechanism 147, and a partition wall 148.

The control board 143 has a driver IC section. The driver IC section has an inverter and outputs a drive current to the coil 142a of the electric actuator 142. The target magnet 144 is a permanent magnet that rotates together with the rotor 142b. The Hall IC section 145 detects changes in magnetic flux accompanying rotation of the target magnet 144. The rotation state of the rotor 142b can be determined by the Hall IC section 145 detecting changes in magnetic flux accompanying the rotation of the target magnet 144.

The deceleration mechanism 146 decelerates the rotation of the rotor 142b and transmits the deceleration to the rotation-linear motion conversion mechanism 147. The rotational linear motion conversion mechanism 147 converts the rotational motion transmitted from the deceleration mechanism 146 into linear motion and transmits the linear motion to the valve body 141 . The partition wall 148 is a member that partitions the internal space of the bypass flow rate adjustment valve 14d into a space where the refrigerant exists and a space where electrical components such as the control board 143 and the coil 142a are accommodated. In this example, the rotor 142b, the rotation-to-linear motion conversion mechanism 147, and the rotation-to-linear motion conversion mechanism 147 are arranged in a space where the refrigerant exists.

The operation of the electric actuator 142 is controlled by instruction value information regarding the opening degree of the electric expansion valve output from the control device 60. Specifically, the instruction value information regarding the opening degree of the electric expansion valve outputted from the control device 60 is output to the control board 143, and the driver IC section of the control board 143 outputs the instruction value information regarding the opening degree of the electric expansion valve. A drive current (in other words, an operating current) according to the information is output to the coil 142a.

By precisely controlling the drive current applied to the coil 142a, a rotating magnetic field is created, which rotates the rotor 142b equipped with a permanent magnet, and the rotational force is transferred to the valve body 141 via the deceleration mechanism 146 and the rotation-to-linear conversion mechanism 147. The opening area of the refrigerant passage (in other words, the aperture opening degree) is varied by converting the movement to the vertical direction.

The bypass flow rate adjustment valve 14d has a fully open function in which it functions simply as a refrigerant passage without exhibiting much of the refrigerant pressure reduction action and flow rate adjustment action by setting the throttle opening to the fully open state. The bypass flow rate adjustment valve 14d has a fully closing function of closing the refrigerant passage by fully closing the throttle opening.

As shown in FIG. 1, the refrigeration cycle 10 includes a heating expansion valve 14a, a cooling expansion valve 14b, and a cooling expansion valve 14c. The heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 14c are electric expansion valves having the same basic configuration as the bypass flow rate adjustment valve 14d.

The heating expansion valve 14a, the cooling expansion valve 14b, the cooling expansion valve 14c, and the bypass flow rate adjustment valve 14d can switch the refrigerant circuit by exhibiting the above-described fully closing function. Therefore, the heating expansion valve 14a, the cooling expansion valve 14b, the cooling expansion valve 14c, and the bypass flow rate adjustment valve 14d also function as a refrigerant circuit switching section.

The heating expansion valve 14a, the cooling expansion valve 14b, the cooling expansion valve 14c, and the bypass flow rate adjustment valve 14d are formed by combining a variable throttle mechanism that does not have a full closing function and an on-off valve that opens and closes the throttle passage. You may. In this case, each on-off valve becomes a refrigerant circuit switching section.

The water-refrigerant heat exchanger 13 exchanges heat between the high-pressure refrigerant discharged from the compressor 11 and the high-temperature heat medium circulating in the high-temperature heat medium circuit 30, and radiates the heat of the high-pressure refrigerant to the high-temperature heat medium. This is a heat exchange section for heat radiation. The water-refrigerant heat exchanger 13 is a condensing heat exchanger that exchanges heat between the high-pressure refrigerant discharged from the compressor 11 and the high-temperature side heat medium to condense the high-pressure refrigerant.

The outlet of the refrigerant passage of the water-refrigerant heat exchanger 13 is connected to the inlet side of the second three-way joint 12b. The inlet side of the heating expansion valve 14a is connected to one outlet of the second three-way joint 12b. One inlet side of the fourth three-way joint 12d is connected to the other outlet of the second three-way joint 12b.

A refrigerant passage from the other outlet of the second three-way joint 12b to one inlet of the fourth three-way joint 12d is a dehumidification passage 21a. A dehumidification on-off valve 22a is arranged in the dehumidification passage 21a.

The dehumidification on-off valve 22a is an on-off valve that opens and closes the dehumidification passage 21a. The dehumidifying on-off valve 22a is an electromagnetic valve whose opening/closing operation is controlled by a control voltage output from the control device 60. The dehumidification on-off valve 22a can switch the refrigerant circuit by opening and closing the dehumidification passage 21a. Therefore, the dehumidifying on-off valve 22a is a refrigerant circuit switching section.

The heating expansion valve 14a is a pressure reducing part on the outdoor heat exchanger side that reduces the pressure of the refrigerant flowing into the outdoor heat exchanger 15 during heating mode or the like. The heating expansion valve 14 a is a flow rate adjustment section on the outdoor heat exchanger side that adjusts the flow rate (mass flow rate) of the refrigerant flowing into the outdoor heat exchanger 15 .

The refrigerant inlet side of the outdoor heat exchanger 15 is connected to the outlet of the heating expansion valve 14a. The outdoor heat exchanger 15 is an outside air heat exchange unit that exchanges heat between the refrigerant flowing out from the heating expansion valve 14a and the outside air blown by an outside air fan (not shown). The outdoor heat exchanger 15 is arranged on the front side of the drive device chamber. Therefore, when the vehicle is running, the outdoor heat exchanger 15 can be exposed to the running wind that has flowed into the drive device chamber through the grille.

The refrigerant outlet of the outdoor heat exchanger 15 is connected to the inlet side of the third three-way joint 12c. One outlet of the third three-way joint 12c is connected to the other inlet of the fourth three-way joint 12d via a first check valve 16a. The first inflow port side of the four-way joint 12x is connected to the other outflow port of the third three-way joint 12c.

The four-way joint 12x is a joint portion having four inlets and outlets that communicate with each other. As the four-way joint 12x, a joint portion formed similarly to the three-way joint described above can be employed. The four-way joint 12x may be formed by combining two three-way joints.

The refrigerant passage leading from the other outlet of the third three-way joint 12c to the first inlet of the four-way joint 12x is the heating passage 21b. A heating on-off valve 22b is arranged in the heating passage 21b.

The heating on-off valve 22b is an on-off valve that opens and closes the heating passage 21b. The basic configuration of the heating on-off valve 22b is the same as that of the dehumidification on-off valve 22a. Therefore, the heating on-off valve 22b is a refrigerant circuit switching section.

The first check valve 16a allows the refrigerant to flow from the third three-way joint 12c side to the fourth three-way joint 12d side, and prohibits the refrigerant from flowing from the fourth three-way joint 12d side to the third three-way joint 12c side. do.

The inflow port of the fifth three-way joint 12e is connected to the outflow port of the fourth three-way joint 12d. One outlet of the fifth three-way joint 12e is connected to the refrigerant inlet side of the indoor evaporator 18 via a cooling expansion valve 14b.

The cooling expansion valve 14b is a pressure reducing part on the indoor evaporator side that reduces the pressure of the refrigerant flowing into the indoor evaporator 18 during the cooling mode, the hot gas dehumidification heating mode, and the like. Therefore, the cooling expansion valve 14b becomes a heating section side pressure reducing section during the hot gas dehumidifying/heating mode and the like. Furthermore, the cooling expansion valve 14b is a flow rate adjustment section on the indoor evaporator side that adjusts the flow rate (mass flow rate) of the refrigerant flowing into the indoor evaporator 18.

The indoor evaporator 18 is arranged inside the air conditioning case 51 of the indoor air conditioning unit 50. The indoor evaporator 18 is a cooling heat exchange unit that exchanges heat between the low-pressure refrigerant whose pressure has been reduced by the cooling expansion valve 14b and the air blown into the vehicle interior from the indoor blower 52. The indoor evaporator 18 cools the air by evaporating the low-pressure refrigerant and exhibiting an endothermic action.

The second inlet side of the four-way joint 12x is connected to the refrigerant outlet of the indoor evaporator 18 via the evaporation pressure regulating valve 14e. The evaporation pressure regulating valve 14e is a variable throttle mechanism that maintains the refrigerant evaporation temperature in the indoor evaporator 18 at a predetermined temperature (for example, a temperature at which frost formation on the indoor evaporator 18 can be suppressed) or higher.

The evaporation pressure regulating valve 14e is a variable throttling mechanism (in other words, an electric expansion valve) configured with an electrical mechanism similar to the heating expansion valve 14a and the like. The evaporation pressure regulating valve 14e may be a variable throttle mechanism configured with a mechanical mechanism that increases the valve opening degree as the pressure of the refrigerant on the refrigerant outlet side of the indoor evaporator 18 increases.

The other outlet of the fifth three-way joint 12e is connected to the inlet side of the refrigerant passage of the chiller 20 via a cooling expansion valve 14c.

The cooling expansion valve 14c is a pressure reducing part on the chiller side that reduces the pressure of the refrigerant flowing into the chiller 20 during the cooling cooling mode, the hot gas heating mode, and the like. Therefore, the cooling expansion valve 14c becomes a heating part side pressure reducing part during the hot gas heating mode and the like. Furthermore, the cooling expansion valve 14c is a flow rate adjustment section on the chiller side that adjusts the flow rate (mass flow rate) of the refrigerant flowing into the chiller 20.

The chiller 20 is a temperature adjustment heat exchange unit that exchanges heat between the low-pressure refrigerant whose pressure has been reduced by the cooling expansion valve 14c and the low-temperature side heat medium circulating in the low-temperature side heat medium circuit 40. The chiller 20 cools the low-temperature heat medium by evaporating the low-pressure refrigerant and exerting an endothermic action.

A third inlet side of the four-way joint 12x is connected to the outlet of the refrigerant passage of the chiller 20. The other inlet side of the sixth three-way joint 12f is connected to the outflow port of the four-way joint 12x. The inlet side of the compressor 11 is connected to the outlet of the sixth three-way joint 12f.

The sixth three-way joint 12f connects the flow of the heating section side refrigerant flowing out from the heating section side pressure reducing section and the bypass side refrigerant flow flowing out from the bypass flow rate adjustment valve 14d during the hot gas heating mode, etc. It becomes a confluence part where the water flows out to the suction port side of No. 11.

The refrigerant passage from the outlet of the sixth three-way joint 12f to the suction port of the compressor 11 is a suction side passage 21d forming a suction side flow path.

Next, the high temperature side heat medium circuit 30 shown in FIG. 1 will be explained. The high temperature side heat medium circuit 30 is a heat medium circulation circuit that circulates a high temperature side heat medium. In this embodiment, an ethylene glycol aqueous solution is used as the high temperature side heat medium. The high temperature side heat medium circuit 30 includes a heat medium passage of the water/refrigerant heat exchanger 13, a high temperature side pump 31, a heater core 32, and the like.

The high temperature side pump 31 is a high temperature side heat medium pumping section that pumps the high temperature side heat medium flowing out from the heat medium passage of the water-refrigerant heat exchanger 13 to the heat medium inlet side of the heater core 32. The high temperature side pump 31 is an electric pump whose rotation speed (that is, pumping capacity) is controlled by a control voltage output from the control device 60.

The heater core 32 is a heating heat exchanger that heats the air by exchanging heat between the high-temperature side heat medium heated by the water-refrigerant heat exchanger 13 and the air that has passed through the indoor evaporator 18 . The heater core 32 is arranged inside the air conditioning case 51 of the indoor air conditioning unit 50. The heating medium outlet of the heater core 32 is connected to the inlet side of the heating medium passage of the water/refrigerant heat exchanger 13 .

Therefore, each component of the water-refrigerant heat exchanger 13 and the high-temperature side heat medium circuit 30 of this embodiment uses one discharged refrigerant branched at the first three-way joint 12a as a heat source to heat air, which is an object to be heated. This is a heating section that heats.

The low temperature side heat medium circuit 40 is a heat medium circuit that circulates a low temperature side heat medium. In this embodiment, the same type of fluid as the high temperature side heat medium is used as the low temperature side heat medium. The low temperature side heat medium circuit 40 is connected to a low temperature side pump 41, a cooling water passage 70a of the battery 70, a heat medium passage of the chiller 20, and the like.

The low temperature side pump 41 is a low temperature side heat medium pumping section that pumps the low temperature side heat medium flowing out of the cooling water passage 70a of the battery 70 to the inlet side of the heat medium passage of the chiller 20. The basic configuration of the low temperature side pump 41 is the same as that of the high temperature side pump 31. The outlet side of the heat medium passage of the chiller 20 is connected to the inlet side of the cooling water passage 70a of the battery 70.

The cooling water passage 70a of the battery 70 is a cooling water passage formed to cool the battery 70 by circulating the low temperature side heat medium cooled by the chiller 20. The cooling water passage 70a is formed inside a dedicated battery case that accommodates a plurality of stacked battery cells.

The cooling water passage 70a has a passage configuration in which a plurality of passages are connected in parallel inside the battery case. Thereby, all the battery cells can be equally cooled in the cooling water passage 70a. The inlet side of the low temperature side pump 41 is connected to the outlet of the cooling water passage 70a.

Next, the indoor air conditioning unit 50 will be described using FIG. 2. The indoor air conditioning unit 50 is a unit that integrates a plurality of components in order to blow air adjusted to an appropriate temperature for air conditioning the vehicle interior to appropriate locations within the vehicle interior. The indoor air conditioning unit 50 is arranged inside an instrument panel at the forefront of the vehicle interior.

The indoor air conditioning unit 50 is formed by accommodating an indoor blower 52, an indoor evaporator 18, a heater core 32, etc. in an air conditioning case 51 that forms an air passage. The air conditioning case 51 is molded from a resin (for example, polypropylene) that has a certain degree of elasticity and excellent strength.

An inside/outside air switching device 53 is disposed at the most upstream side of the air conditioning case 51 in terms of air flow. The inside/outside air switching device 53 selectively introduces inside air (ie, vehicle interior air) and outside air (ie, vehicle exterior air) into the air conditioning case 51 . The operation of the inside/outside air switching device 53 is controlled by a control signal output from the control device 60.

An indoor blower 52 is arranged downstream of the inside/outside air switching device 53 in the air flow. The indoor blower 52 is a blower unit that blows air sucked in via the inside/outside air switching device 53 into the vehicle interior. The rotation speed (that is, the blowing capacity) of the indoor blower 52 is controlled by a control voltage output from the control device 60.

The indoor evaporator 18 and the heater core 32 are arranged downstream of the indoor blower 52 in the air flow. The indoor evaporator 18 is arranged upstream of the heater core 32 in the air flow. A cold air bypass passage 55 is formed in the air conditioning case 51 to allow the air that has passed through the indoor evaporator 18 to flow around the heater core 32 .

An air mix door 54 is disposed on the air flow downstream side of the indoor evaporator 18 in the air conditioning case 51 and on the air flow upstream side of the heater core 32 and the cold air bypass passage 55.

The air mix door 54 adjusts the ratio of the amount of air that passes through the heater core 32 side and the amount of air that passes through the cold air bypass passage 55 out of the air that has passed through the indoor evaporator 18 . The operation of the actuator for driving the air mix door 54 is controlled by a control signal output from the control device 60.

A mixing space 56 is formed downstream of the heater core 32 and the cold air bypass passage 55 in the air flow. The mixing space 56 is a space in which the air heated by the heater core 32 and the air that has passed through the cold air bypass passage 55 and has not been heated are mixed.

Therefore, in the indoor air conditioning unit 50, the temperature of the air (i.e., conditioned air) that is mixed in the mixing space 56 and blown into the vehicle interior can be adjusted by adjusting the opening degree of the air mix door 54. The air mix door 54 of this embodiment is an air flow rate adjustment section that adjusts the flow rate of air heat exchanged in the heater core 32.

A plurality of opening holes (not shown) are formed at the most downstream part of the air conditioning case 51 in the air flow direction to blow out conditioned air toward various locations within the vehicle interior. A blowout mode door (not shown) is arranged in each of the plurality of openings to open and close each opening. The operation of the actuator for driving the blowout mode door is controlled by a control signal output from the control device 60.

Therefore, in the indoor air conditioning unit 50, the air conditioned air adjusted to an appropriate temperature can be blown out to an appropriate location in the vehicle interior by switching the opening hole through which the blowout mode door opens and closes.

Next, the electric control section of this embodiment will be explained. The control device 60 includes a well-known microcomputer including a CPU, ROM, RAM, etc., and its peripheral circuits. The control device 60 performs various calculations and processes based on a control program stored in the ROM. Then, the control device 60 controls the operations of the various controlled devices 11, 14a to 14e, 22a, 22b, 31, 41, 52, 53, etc. connected to the output side, based on the calculation and processing results.

As shown in the block diagram of FIG. 3, on the input side of the control device 60, there are an inside temperature sensor 61a, an outside temperature sensor 61b, a solar radiation sensor 61c, a discharge refrigerant pressure sensor 62a, an outdoor unit refrigerant pressure sensor 62b, and an evaporator refrigerant pressure sensor. Sensor 62c, chiller refrigerant pressure sensor 62d, suction refrigerant pressure sensor 62e, discharge refrigerant temperature sensor 62f, high pressure refrigerant temperature sensor 62g, outdoor unit refrigerant temperature sensor 62h, evaporator refrigerant temperature sensor 62i, chiller refrigerant temperature sensor 62j, high temperature side heat A group of control sensors such as a medium temperature sensor 63a, a low temperature side heat medium temperature sensor 63b, a battery temperature sensor 64, and an air conditioned air temperature sensor 65 are connected.

The inside temperature sensor 61a is an inside temperature detection section that detects the inside temperature (inside temperature) Tr of the vehicle interior. The outside temperature sensor 61b is an outside temperature detection section that detects the outside temperature (outside temperature) Tam of the vehicle interior. The solar radiation sensor 61c is a solar radiation detection unit that detects the solar radiation amount As irradiated into the vehicle interior.

The discharge refrigerant pressure sensor 62a is a discharge refrigerant temperature detection section that detects the discharge refrigerant pressure Pd of the discharge refrigerant discharged from the compressor 11. Specifically, the discharge refrigerant pressure sensor 62a detects the pressure of the refrigerant flowing through the refrigerant passage from the refrigerant discharge port of the compressor to the inlet of the first three-way joint 12a.

The outdoor unit refrigerant pressure sensor 62b is an outdoor unit refrigerant pressure detection unit that detects the outdoor unit refrigerant pressure P2, which is the pressure of the refrigerant flowing out from the outdoor heat exchanger 15. Specifically, the outdoor unit refrigerant pressure sensor 62b detects the pressure of the refrigerant flowing through the refrigerant passage from the refrigerant outlet of the outdoor heat exchanger 15 to one inlet of the third three-way joint 12c.

The evaporator refrigerant pressure sensor 62c is an evaporator temperature detection unit for detecting the evaporator refrigerant pressure Pe, which is the pressure of the refrigerant flowing out from the refrigerant passage of the indoor evaporator 18. Specifically, the evaporator refrigerant pressure sensor 62c detects the pressure of the refrigerant flowing through the refrigerant passage from the refrigerant outlet of the indoor evaporator 18 to the refrigerant inlet of the evaporation pressure adjustment valve 14e.

The chiller refrigerant pressure sensor 62d is a chiller refrigerant pressure detection unit that detects the chiller refrigerant pressure Pc, which is the temperature of the refrigerant flowing out from the refrigerant passage of the chiller 20. Specifically, the chiller refrigerant pressure sensor 62d detects the pressure of the refrigerant flowing through the refrigerant passage from the refrigerant outlet of the chiller 20 to the third inlet of the four-way joint 12x.

The suction refrigerant pressure sensor 62e is a suction pressure detection unit for detecting the suction refrigerant pressure Ps, which is the pressure of the suction refrigerant sucked into the compressor 11. Specifically, the suction refrigerant pressure sensor 62e detects the pressure of the refrigerant flowing through the refrigerant passage from the outlet of the sixth three-way joint 12f to the refrigerant suction port of the compressor 11.

The discharge refrigerant temperature sensor 62f is a discharge refrigerant temperature detection section that detects the discharge refrigerant temperature Td of the discharge refrigerant discharged from the compressor 11.

The high-pressure refrigerant temperature sensor 62g is a high-pressure refrigerant temperature detection unit that detects the high-pressure refrigerant temperature T1, which is the temperature of the refrigerant flowing out from the water-refrigerant heat exchanger 13.

The outdoor unit refrigerant temperature sensor 62h is an outdoor unit refrigerant temperature detection unit that detects the outdoor unit refrigerant temperature T2, which is the temperature of the refrigerant flowing out from the outdoor heat exchanger 15.

The evaporator refrigerant temperature sensor 62i is an evaporator temperature detection unit for detecting the evaporator refrigerant temperature Te, which is the temperature of the refrigerant flowing out from the indoor evaporator 18.

The chiller refrigerant temperature sensor 62j is a chiller refrigerant temperature detection unit that detects the chiller refrigerant temperature Tc, which is the temperature of the refrigerant flowing out from the refrigerant passage of the chiller 20. The chiller refrigerant temperature Tc can be used as the suction refrigerant temperature Ts, which is the temperature of the suction refrigerant sucked into the compressor 11. Therefore, the chiller refrigerant temperature sensor 62j of this embodiment is a suction pressure detection section.

Although this embodiment employs a detection section in which a refrigerant pressure sensor and a refrigerant temperature sensor are configured separately, it is of course possible to employ a refrigerant temperature and pressure sensor in which a pressure detection section and a temperature detection section are integrated. You can.

The high temperature side heat medium temperature sensor 63a is a high temperature side heat medium temperature detection section that detects the high temperature side heat medium temperature TWH, which is the temperature of the high temperature side heat medium flowing into the heater core 32. The low temperature side heat medium temperature sensor 63b is a low temperature side heat medium temperature detection section that detects the low temperature side heat medium temperature TWL, which is the temperature of the low temperature side heat medium flowing into the cooling water passage 70a of the battery 70.

Battery temperature sensor 64 is a battery temperature detection section that detects battery temperature TB, which is the temperature of battery 70. The battery temperature sensor 64 includes a plurality of temperature sensors and detects the temperature of a plurality of locations on the battery 70. Therefore, the control device 60 can detect the temperature difference and temperature distribution of each battery cell forming the battery 70. Furthermore, as the battery temperature TB, the average value of the detection values of a plurality of temperature sensors is adopted.

The conditioned air temperature sensor 65 is a conditioned air temperature detection section that detects the temperature TAV of the air blown from the mixing space 56 into the vehicle interior. The air temperature TAV is the object temperature of air, which is the object to be heated.

Furthermore, as shown in FIG. 3, the input side of the control device 60 is connected by wire or wirelessly to an operation panel 69 disposed near the instrument panel at the front of the vehicle interior. Operation signals from various operation switches provided on the operation panel 69 are input to the control device 60 .

Specifically, various operation switches provided on the operation panel 69 include an auto switch, an air conditioner switch, an air volume setting switch, a temperature setting switch, and the like.

The auto switch is an automatic control setting section that sets or cancels automatic control operation of the vehicle air conditioner 1. The air conditioner switch is a cooling requesting unit that requests the indoor evaporator 18 to cool the air. The air volume setting switch is an air volume setting section that manually sets the air volume of the indoor blower 52. The temperature setting switch is a temperature setting section that sets a set temperature Tset in the vehicle interior.

Note that the control device 60 of this embodiment is configured integrally with a control section that controls various devices to be controlled connected to its output side. Therefore, the configuration (hardware and software) that controls the operation of each device to be controlled constitutes a control unit that controls the operation of each device to be controlled.

For example, a component of the control device 60 that controls the refrigerant discharge capacity of the compressor 11 constitutes a discharge capacity control section 60a (in other words, a compressor control section). The configuration that controls the operation of the heating section side pressure reducing section (in this embodiment, the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 14c) constitutes a heating section side control section 60b. A configuration that controls the operation of the bypass flow rate adjustment valve 14d constitutes a bypass side control section 60c.

Next, the operation of the vehicle air conditioner 1 of this embodiment with the above configuration will be explained. In the vehicle air conditioner 1 of this embodiment, various driving modes are switched in order to air condition the vehicle interior and adjust the temperature of the battery 70. Switching of the driving mode is performed by executing a control program stored in the control device 60 in advance. Various operation modes will be explained below.

First, an operation mode in which the refrigerant is not allowed to flow through the bypass passage 21c will be described. The operating modes in which the refrigerant is not circulated through the bypass passage 21c include (a) cooling mode, (b) series dehumidifying heating mode, and (c) outside air endothermic heating mode.

(a) Cooling Mode The cooling mode is an operation mode in which the interior of the vehicle is cooled by blowing cooled air into the vehicle interior. In the control program, the cooling mode is selected mainly when the outside temperature Tam is relatively high (25° C. or higher in this embodiment), such as in the summer.

The cooling mode includes an individual cooling mode and a cooling cooling mode. The independent cooling mode is an operation mode in which the interior of the vehicle is cooled without cooling the battery 70. The cooling air-conditioning mode is an operation mode in which the battery 70 is cooled and the interior of the vehicle is cooled.

In the control program of this embodiment, an operation mode for cooling the battery 70 is executed when the battery temperature TB detected by the battery temperature sensor 64 is equal to or higher than a predetermined reference upper limit temperature KTBH. This also applies to other operation modes described below.

(a-1) Independent cooling mode In the refrigeration cycle 10 in the independent cooling mode, the control device 60 sets the heating expansion valve 14a to a fully open state, the cooling expansion valve 14b to a throttle state that exerts a refrigerant pressure reducing effect, and The expansion valve 14c is brought into a fully closed state, and the bypass flow rate adjustment valve 14d is brought into a fully closed state. Further, the control device 60 closes the dehumidification on-off valve 22a and closes the heating on-off valve 22b.

Therefore, in the refrigeration cycle 10 in the independent cooling mode, the refrigerant discharged from the compressor 11 is transferred to the water-refrigerant heat exchanger 13, the heating expansion valve 14a which is in the fully open state, the outdoor heat exchanger 15, and the throttle state. The refrigerant circuit is switched to a refrigerant circuit that circulates in the order of the cooling expansion valve 14b, the indoor evaporator 18, the suction side passage 21d, and the suction port of the compressor 11.

Further, the control device 60 controls the refrigerant discharge capacity of the compressor 11 so that the evaporator refrigerant temperature Te detected by the evaporator refrigerant temperature sensor 62i approaches the target evaporator temperature TEO. The target evaporator temperature TEO is determined based on the target outlet temperature TAO with reference to a control map stored in the control device 60 in advance.

The target blowout temperature TAO is the target temperature of air blown into the vehicle interior. The target air temperature TAO is based on the inside temperature Tr detected by the inside temperature sensor 61a, the outside temperature Tam detected by the outside temperature sensor 61b, the amount of solar radiation As detected by the solar radiation sensor 61c, and the settings set by the temperature setting switch. It is calculated using the temperature Tset, etc. In the control map, the target evaporator temperature TEO is determined to increase as the target outlet temperature TAO increases.

Further, the control device 60 controls the throttle opening degree of the cooling expansion valve 14b so that the degree of superheating SH of the suction refrigerant approaches a predetermined reference degree of superheating KSH (5° C. in this embodiment). The degree of superheating SH of the suction refrigerant is determined using the chiller refrigerant pressure Pc detected by the chiller refrigerant pressure sensor 62d and the chiller refrigerant temperature Tc (in other words, the suction refrigerant temperature Ts) detected by the chiller refrigerant temperature sensor 62j. can do.

Further, in the high temperature side heat medium circuit 30 in the independent cooling mode, the control device 60 operates the high temperature side pump 31 so as to exhibit a predetermined reference pumping capacity. Therefore, in the high temperature side heat medium circuit 30 in the independent cooling mode, the heat medium pumped from the high temperature side pump 31 is sent to the heat medium passage of the water/refrigerant heat exchanger 13, the heater core 32, and the suction port of the high temperature side pump 31 in this order. circulate.

Furthermore, in the indoor air conditioning unit 50 in the independent cooling mode, the control device 60 controls the air blowing capacity of the indoor blower 52 based on the target air temperature TAO with reference to a control map stored in the control device 60 in advance. Further, the control device 60 adjusts the opening degree of the air mix door 54 so that the air temperature TAV detected by the conditioned air temperature sensor 65 approaches the target outlet temperature TAO. Furthermore, the control device 60 appropriately controls the operations of other controlled devices.

Therefore, in the refrigeration cycle 10 in the independent cooling mode, the water-refrigerant heat exchanger 13 and the outdoor heat exchanger 15 function as a condenser that radiates heat and condenses the refrigerant, and the indoor evaporator 18 functions as an evaporator that evaporates the refrigerant. A vapor compression type refrigeration cycle is constructed to function as

In the high temperature side heat medium circuit 30 in the independent cooling mode, the high temperature side heat medium heated in the water/refrigerant heat exchanger 13 flows into the heater core 32 .

In the indoor air conditioning unit 50 in the independent cooling mode, air blown from the indoor blower 52 is cooled by the indoor evaporator 18. The air cooled by the indoor evaporator 18 is reheated by the heater core 32 in accordance with the opening degree of the air mix door 54 so as to approach the target blowout temperature TAO. Then, the temperature-adjusted air is blown into the vehicle interior, thereby realizing cooling of the vehicle interior.

(a-2) Cooling/Air Conditioning Mode In the refrigeration cycle 10 in the cooling/cooling mode, the control device 60 puts the cooling expansion valve 14c in the throttle state compared to the independent cooling mode.

Therefore, in the refrigeration cycle 10 in the cooling cooling mode, the refrigerant discharged from the compressor 11 circulates in the same way as in the independent cooling mode. At the same time, the refrigerant discharged from the compressor 11 is transferred to the water-refrigerant heat exchanger 13, the heating expansion valve 14a that is fully open, the outdoor heat exchanger 15, the cooling expansion valve 14c that is throttled, and the chiller. 20, the suction side passage 21d, and the suction port of the compressor 11 in this order. That is, the indoor evaporator 18 and chiller 20 are switched to a refrigerant circuit connected in parallel to the flow of refrigerant.

Further, the control device 60 controls the throttle opening degree of the cooling expansion valve 14c so that the throttle opening degree is a predetermined throttle opening degree for the cooling air-conditioning mode.

Further, in the high temperature side heat medium circuit 30 in the cooling cooling mode, the control device 60 operates the high temperature side pump 31 similarly to the independent cooling mode.

Further, in the low temperature side heat medium circuit 40 in the cooling cooling mode, the control device 60 operates the low temperature side pump 41 so as to exhibit a predetermined reference pumping capacity. Therefore, in the low temperature side heat medium circuit 40 in the independent cooling mode, the heat medium pumped from the low temperature side pump 41 is transferred to the heat medium passage of the chiller 20, the cooling water passage 70a of the battery 70, and the suction port of the low temperature side pump 41. cycle in order.

Furthermore, in the indoor air conditioning unit 50 in the cooling cooling mode, the control device 60 controls the air blowing capacity of the indoor blower 52 and the opening degree of the air mix door 54, as in the independent cooling mode. Furthermore, the control device 60 appropriately controls the operations of other controlled devices, similarly to the independent cooling mode.

Therefore, in the refrigeration cycle 10 in the cooling cooling mode, the water refrigerant heat exchanger 13 and the outdoor heat exchanger 15 function as a condenser, and the indoor evaporator 18 and the chiller 20 function as an evaporator. A cycle is constructed.

In the high temperature side heat medium circuit 30 in the cooling cooling mode, the high temperature side heat medium heated in the water/refrigerant heat exchanger 13 flows into the heater core 32 as in the independent cooling mode.

In the low temperature side heat medium circuit 40 in the cooling cooling mode, the low temperature side heat medium pumped from the low temperature side pump 41 flows into the chiller 20 . The low-temperature side heat medium that has flowed into the chiller 20 is cooled by exchanging heat with the low-pressure refrigerant. The low-temperature heat medium cooled by the chiller 20 flows through the cooling water passage 70a of the battery 70. This cools the battery 70.

In the indoor air conditioning unit 50 in the cooling cooling mode, as in the independent cooling mode, temperature-adjusted air is blown into the vehicle interior, thereby achieving cooling in the vehicle interior.

(b) Series Dehumidification and Heating Mode The series dehumidification and heating mode is an operation mode in which cooled and dehumidified air is reheated and blown into the vehicle interior to perform dehumidification and heating within the vehicle interior. In the control program, the serial dehumidification heating mode is selected when the outside temperature Tam is in a predetermined medium-high temperature range (in this embodiment, 10° C. or more and less than 25° C.).

The series dehumidifying and heating mode includes an individual series dehumidifying and heating mode and a cooling series dehumidifying and heating mode. The independent series dehumidification/heating mode is an operation mode in which the vehicle interior is dehumidified and heated without cooling the battery 70. The cooling serial dehumidification/heating mode is an operation mode in which the battery 70 is cooled and the interior of the vehicle is dehumidified and heated.

(b-1) Individual series dehumidification heating mode In the refrigeration cycle 10 in the individual series dehumidification heating mode, the control device 60 puts the heating expansion valve 14a in the throttled state, the cooling expansion valve 14b in the throttled state, and the cooling expansion valve 14b in the throttled state. 14c is fully closed, and the bypass flow rate adjustment valve 14d is fully closed. Further, the control device 60 closes the dehumidification on-off valve 22a and closes the heating on-off valve 22b.

Therefore, in the refrigeration cycle 10 in the single series dehumidifying heating mode, the refrigerant discharged from the compressor 11 is transferred to the water-refrigerant heat exchanger 13, the heating expansion valve 14a which is in the throttled state, the outdoor heat exchanger 15, the throttle The refrigerant circuit is switched to circulate in the order of the cooling expansion valve 14b, the indoor evaporator 18, the suction side passage 21d, and the suction port of the compressor 11.

Further, the control device 60 controls the aperture opening degrees of the heating expansion valve 14a and the cooling expansion valve 14b with reference to a control map stored in the control device 60 in advance. In the control map, the throttle opening degrees of the heating expansion valve 14a and the cooling expansion valve 14b are determined so that the degree of superheating SH of the suction refrigerant approaches the reference degree of superheating KSH.

Further, in the high temperature side heat medium circuit 30 in the independent series dehumidifying heating mode, the control device 60 operates the high temperature side pump 31 similarly to the independent cooling mode.

In the indoor air conditioning unit 50 in the independent series dehumidifying heating mode, the control device 60 controls the air blowing capacity of the indoor blower 52 and the opening degree of the air mix door 54, similarly to the independent cooling mode. Furthermore, the control device 60 appropriately controls the operations of other controlled devices.

Therefore, in the refrigeration cycle 10 in the single series dehumidification/heating mode, a vapor compression type refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser and the indoor evaporator 18 functions as an evaporator.

Furthermore, in the single series dehumidifying heating mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 15 is higher than the outside air temperature Tam, the outdoor heat exchanger 15 is made to function as a condenser. Furthermore, when the saturation temperature of the refrigerant in the outdoor heat exchanger 15 is lower than the outside air temperature Tam, the outdoor heat exchanger 15 is made to function as an evaporator.

In the high temperature side heat medium circuit 30 in the single series dehumidification/heating mode, the high temperature side heat medium heated in the water/refrigerant heat exchanger 13 flows into the heater core 32 .

In the indoor air conditioning unit 50 in the single series dehumidifying heating mode, air blown from the indoor blower 52 is cooled and dehumidified by the indoor evaporator 18. The air cooled and dehumidified by the indoor evaporator 18 is reheated by the heater core 32 in accordance with the opening degree of the air mix door 54 so as to approach the target blowout temperature TAO. By blowing the temperature-adjusted air into the vehicle interior, dehumidifying and heating the vehicle interior is achieved.

(b-2) Cooling series dehumidification/heating mode In the refrigeration cycle 10 in the cooling series dehumidification/heating mode, the control device 60 puts the cooling expansion valve 14c in the throttle state compared to the single series dehumidification/heating mode.

Therefore, in the refrigeration cycle 10 in the cooling serial dehumidifying heating mode, the refrigerant discharged from the compressor 11 circulates in the same way as in the single serial dehumidifying heating mode. At the same time, the refrigerant discharged from the compressor 11 is transferred to the water-refrigerant heat exchanger 13, the heating expansion valve 14a in the throttled state, the outdoor heat exchanger 15, the cooling expansion valve 14c in the throttled state, and the chiller. 20, the suction side passage 21d, and the suction port of the compressor 11 in this order. That is, the indoor evaporator 18 and chiller 20 are switched to a refrigerant circuit connected in parallel to the flow of refrigerant.

Further, in the high temperature side heat medium circuit 30 in the cooling serial dehumidification/heating mode, the control device 60 operates the high temperature side pump 31 similarly to the independent cooling mode.

Further, in the low temperature side heat medium circuit 40 in the cooling series dehumidifying heating mode, the control device 60 operates the low temperature side pump 41 similarly to the cooling cooling mode.

Furthermore, in the indoor air conditioning unit 50 in the cooling serial dehumidification/heating mode, the control device 60 controls the air blowing capacity of the indoor blower 52 and the opening degree of the air mix door 54, similarly to the independent cooling mode. Furthermore, the control device 60 appropriately controls the operations of other controlled devices, similarly to the single series dehumidification/heating mode.

Therefore, in the refrigeration cycle 10 in the cooling series dehumidification heating mode, a vapor compression type refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser, and the indoor evaporator 18 and chiller 20 function as evaporators. Ru.

Furthermore, in the cooling series dehumidifying heating mode, similarly to the single series dehumidifying heating mode, when the saturation temperature of the refrigerant in the outdoor heat exchanger 15 is higher than the outside air temperature Tam, the outdoor heat exchanger 15 is made to function as a condenser. . Furthermore, when the saturation temperature of the refrigerant in the outdoor heat exchanger 15 is lower than the outside air temperature Tam, the outdoor heat exchanger 15 is made to function as an evaporator.

In the high temperature side heat medium circuit 30 in the cooling serial dehumidification/heating mode, the high temperature side heat medium heated in the water/refrigerant heat exchanger 13 flows into the heater core 32 as in the independent cooling mode.

In the low temperature side heat medium circuit 40 in the cooling serial dehumidification heating mode, the low temperature side heat medium cooled by the chiller 20 flows through the cooling water passage 70a of the battery 70, as in the cooling cooling mode, so that the battery 70 cooled down.

In the indoor air conditioning unit 50 in the cooling serial dehumidifying and heating mode, dehumidifying and heating the vehicle interior is achieved by blowing temperature-adjusted air into the vehicle interior, similarly to the single series dehumidifying and heating mode.

(c) Outside air endothermic heating mode The outside air endothermic heating mode is an operation mode in which the interior of the vehicle is heated by blowing heated air into the interior of the vehicle. In the control program, the outside air endothermic heating mode is selected mainly when the outside air temperature Tam is a relatively low value (in this embodiment, −10° C. or more and less than 0° C.), such as in winter.

The outside air endothermic heating mode includes an independent outside air endothermic heating mode and a cooled outside air endothermic heating mode. The independent outside air heat absorption heating mode is an operation mode in which the interior of the vehicle is heated without cooling the battery 70. The cooling outside air heat absorption and heating mode is an operation mode in which the battery 70 is cooled and the interior of the vehicle is heated.

(c-1) Independent outside air endothermic heating mode In the refrigeration cycle 10 in the independent outside air endothermic heating mode, the control device 60 puts the heating expansion valve 14a in the throttled state, the cooling expansion valve 14b in the fully closed state, and expands the cooling. The valve 14c is fully closed, and the bypass flow rate adjustment valve 14d is fully closed. Further, the control device 60 closes the dehumidification on-off valve 22a and opens the heating on-off valve 22b.

Therefore, in the refrigeration cycle 10 in the independent outside air heat absorption heating mode, the refrigerant discharged from the compressor 11 is transferred to the water-refrigerant heat exchanger 13, the heating expansion valve 14a in the throttled state, the outdoor heat exchanger 15, the heating The refrigerant circuit is switched to a refrigerant circuit in which the refrigerant circulates in the order of the air passage 21b, the suction side passage 21d, and the suction port of the compressor 11.

Further, the control device 60 controls the refrigerant discharge capacity of the compressor 11 so that the discharge refrigerant pressure Pd detected by the discharge refrigerant pressure sensor 62a approaches the target high pressure PDO. The target high pressure PDO is determined based on the target blowout temperature TAO with reference to a control map stored in the control device 60 in advance. In the control map, the target high pressure PDO is determined to increase as the target blowout temperature TAO increases.

Further, the control device 60 controls the opening degree of the heating expansion valve 14a so that the superheat degree SH of the suction refrigerant approaches the reference superheat degree KSH.

Further, in the high temperature side heat medium circuit 30 in the independent outside air heat absorption heating mode, the control device 60 operates the high temperature side pump 31 similarly to the independent cooling mode.

Furthermore, in the indoor air conditioning unit 50 in the independent outside air heat absorption heating mode, the control device 60 controls the blowing capacity of the indoor blower 52 and the opening degree of the air mix door 54, similarly to the independent cooling mode. Furthermore, the control device 60 appropriately controls the operations of other controlled devices.

Therefore, in the refrigeration cycle 10 in the independent outside air heat absorption heating mode, a vapor compression type refrigeration cycle is configured in which the water-refrigerant heat exchanger 13 functions as a condenser and the outdoor heat exchanger 15 functions as an evaporator.

In the independent outside air heat absorption heating mode, the high-temperature side heat medium heated in the water-refrigerant heat exchanger 13 flows into the heater core 32, similarly to the independent cooling mode.

In the indoor air conditioning unit 50 in the independent outside air endothermic heating mode, air blown from the indoor blower 52 passes through the indoor evaporator 18 . The air that has passed through the indoor evaporator 18 is heated by the heater core 32 in accordance with the opening degree of the air mix door 54 so as to approach the target blowout temperature TAO. Then, the temperature-adjusted air is blown into the vehicle interior, thereby realizing heating of the vehicle interior.

(c-2) Cooling outside air endothermic heating mode In the refrigeration cycle 10 in the cooling outside air endothermic heating mode, the control device 60 puts the cooling expansion valve 14c in the throttle state compared to the independent outside air endothermic heating mode. Further, the control device 60 opens the dehumidification on-off valve 22a.

Therefore, in the refrigeration cycle 10 in the cooling outside air endothermic heating mode, the refrigerant discharged from the compressor 11 circulates in the same way as in the independent outside air endothermic heating mode. At the same time, the refrigerant discharged from the compressor 11 is transferred to the water refrigerant heat exchanger 13, the dehumidifying passage 21a, the cooling expansion valve 14c in a throttled state, the chiller 20, the suction side passage 21d, and the suction port of the compressor 11. The refrigerant circuit circulates in this order. That is, the outdoor heat exchanger 15 and chiller 20 are switched to a refrigerant circuit connected in parallel to the flow of refrigerant.

Further, in the high temperature side heat medium circuit 30 in the cooling outside air heat absorption mode, the control device 60 operates the high temperature side pump 31 similarly to the independent cooling mode.

Further, in the low temperature side heat medium circuit 40 in the cooling outside air heat absorption mode, the control device 60 operates the low temperature side pump 41 similarly to the cooling cooling mode.

Further, in the indoor air conditioning unit 50 in the cooling outside air endothermic heating mode, the control device 60 controls the blowing capacity of the indoor blower 52 and the opening degree of the air mix door 54, as in the independent cooling mode. Furthermore, the control device 60 appropriately controls the operations of other controlled devices, similarly to the independent outside air heat absorption heating mode.

Therefore, the refrigeration cycle 10 in the cooling outdoor air absorption heating mode is configured as a vapor compression type refrigeration cycle in which the water-refrigerant heat exchanger 13 functions as a condenser, and the outdoor heat exchanger 15 and chiller 20 function as evaporators. be done.

In the high temperature side heat medium circuit 30 in the cooling outside air endothermic heating mode, the high temperature side heat medium heated in the water/refrigerant heat exchanger 13 flows into the heater core 32 as in the independent cooling mode.

In the low temperature side heat medium circuit 40 in the cooling outside air heat absorption heating mode, the low temperature side heat medium cooled by the chiller 20 flows through the cooling water passage 70a of the battery 70, as in the cooling cooling mode, so that the battery 70 is heated. cooled down.

In the indoor air conditioning unit 50 in the cooling outside air endothermic heating mode, heating of the vehicle interior is achieved by blowing temperature-adjusted air into the vehicle interior, similarly to the independent outside air endothermic heating mode.

Next, an operation mode in which the refrigerant is circulated through the bypass passage 21c will be explained. The operating modes for circulating the refrigerant through the bypass passage 21c include (d) hot gas heating mode, (e) hot gas dehumidifying heating mode, and (f) hot gas series dehumidifying heating mode.

(d) Hot Gas Heating Mode The hot gas heating mode is an operation mode that heats the interior of the vehicle. In the control program, when the outside temperature Tam is extremely low (lower than -10°C in this embodiment) or when the outside air absorption heating mode is in effect, the air heating capacity in the water-refrigerant heat exchanger 13 is insufficient. When it is determined that the hot gas heating mode is present, the hot gas heating mode is selected.

In the control program, when the air temperature TAV is lower than the target blowout temperature TAO, it is determined that the air heating capacity is insufficient. This also applies to other driving modes.

The hot gas heating mode includes an independent hot gas heating mode and a cooled hot gas heating mode. The independent hot gas heating mode is an operation mode in which the interior of the vehicle is heated without cooling the battery 70. The cooling hot gas heating mode is an operation mode in which the battery 70 is cooled and the interior of the vehicle is heated.

(d-1) Independent hot gas heating mode In the refrigeration cycle 10 in the independent hot gas heating mode, the control device 60 fully closes the heating expansion valve 14a, fully closes the cooling expansion valve 14b, and The expansion valve 14c is in a throttled state, and the bypass flow rate adjustment valve 14d is in a throttled state. Further, the control device 60 opens the dehumidification on-off valve 22a and closes the heating on-off valve 22b.

Therefore, in the refrigeration cycle 10 in the independent hot gas heating mode, the refrigerant discharged from the compressor 11 is transferred to the first three-way joint 12a, the water-refrigerant heat exchanger 13, the dehumidification passage 21a, and the cooling It circulates through the expansion valve 14c, the chiller 20, the suction side passage 21d, and the suction port of the compressor 11 in this order. At the same time, the refrigerant discharged from the compressor 11 flows through the first three-way joint 12a, the bypass flow rate adjustment valve 14d arranged in the bypass passage 21c, which is in a throttled state, the suction side passage 21d, and the suction port of the compressor 11, in this order. Switched to circulating refrigerant circuit.

Further, the control device 60 controls the refrigerant discharge capacity of the compressor 11 so that the chiller refrigerant pressure Pc approaches a predetermined first target low pressure PSO1.

Here, controlling the chiller refrigerant pressure Pc corresponding to the suction refrigerant pressure Ps so as to approach a constant pressure is effective for stabilizing the discharge flow rate Gr (mass flow rate) of the compressor 11. More specifically, by setting the suction refrigerant pressure Ps to be a saturated gas phase refrigerant at a constant pressure, the density of the suction refrigerant becomes constant. Therefore, if the suction refrigerant pressure Ps is controlled to approach a constant pressure, the discharge flow rate Gr of the compressor 11 at the same rotation speed can be easily stabilized.

Further, the control device 60 controls the throttle opening degree of the bypass flow rate adjustment valve 14d so that the discharge refrigerant pressure Pd approaches the target high pressure PDO.

Further, the control device 60 controls the throttle opening degree of the cooling expansion valve 14c so that the superheat degree SH of the suction refrigerant approaches the reference superheat degree KSH.

Further, in the high temperature side heat medium circuit 30 in the independent hot gas heating mode, the control device 60 operates the high temperature side pump 31 similarly to the independent cooling mode.

Further, in the low temperature side heat medium circuit 40 in the independent hot gas heating mode, the control device 60 stops the low temperature side pump 41.

Furthermore, in the indoor air conditioning unit 50 in the independent hot gas heating mode, the control device 60 controls the opening degree of the air mix door 54 similarly to the independent cooling mode. In the hot gas heating mode, the opening degree of the air mix door 54 is often controlled so that almost the entire volume of air blown from the indoor blower 52 passes through the heater core 32.

Further, the control device 60 controls the operation of the inside/outside air switching device 53 so as to introduce inside air into the air conditioning case 51 . Furthermore, the control device 60 appropriately controls the operations of other controlled devices.

Therefore, in the refrigeration cycle 10 in the independent hot gas heating mode, the state of the refrigerant changes as described below.

First, the flow of refrigerant discharged from the compressor 11 is branched at the first three-way joint 12a. One of the refrigerants branched off at the first three-way joint 12a flows into the water-refrigerant heat exchanger 13 and radiates heat to the high temperature side heat medium. Thereby, the high temperature side heat medium is heated.

The refrigerant flowing out from the water-refrigerant heat exchanger 13 flows into the dehumidification passage 21a. The refrigerant that has flowed into the dehumidifying passage 21a flows into the cooling expansion valve 14c and is depressurized.

The refrigerant whose pressure is reduced by the cooling expansion valve 14c flows into the chiller 20. In the hot gas heating mode, since the low temperature side pump 41 is stopped, there is no heat exchange between the refrigerant and the low temperature side heat medium in the chiller 20. The refrigerant flowing out of the chiller 20 flows into the other inlet of the sixth three-way joint 12f via the four-way joint 12x.

Further, the other refrigerant branched at the first three-way joint 12a flows into the bypass passage 21c. The pressure of the refrigerant flowing into the bypass passage 21c is reduced when the flow rate is adjusted by the bypass flow rate adjustment valve 14d. The refrigerant whose pressure has been reduced by the bypass flow rate adjustment valve 14d flows into one inlet of the sixth three-way joint 12f.

The refrigerant flowing out from the chiller 20 and the refrigerant flowing out from the bypass flow rate adjustment valve 14d join together at the sixth three-way joint 12f and are mixed. The refrigerant flowing out from the sixth three-way joint 12f is mixed while flowing through the suction side passage 21d, and is sucked into the compressor 11.

As described above, in the refrigeration cycle 10 in the hot gas heating mode, refrigerants with different enthalpies, such as the low enthalpy refrigerant flowing out from the chiller 20 and the high enthalpy refrigerant flowing out from the bypass passage 21c, are mixed and sucked into the compressor 11. I'm letting you do it.

Therefore, in the refrigeration cycle 10 in the hot gas heating mode, the cooling expansion valve 14c becomes the heating section side pressure reducing section.

Further, in the high temperature side heat medium circuit 30 in the independent hot gas heating mode, the high temperature side heat medium heated in the water refrigerant heat exchanger 13 flows into the heater core 32, as in the independent cooling mode.

Furthermore, in the indoor air conditioning unit 50 in the independent hot gas heating mode, heating of the vehicle interior is achieved by blowing temperature-adjusted air into the vehicle interior, similarly to the independent outside air heat absorption heating mode.

Here, the independent hot gas heating mode is an operation mode that is executed when the outside temperature Tam is extremely low. For this reason, if the refrigerant flowing out from the water-refrigerant heat exchanger 13 is allowed to flow into the outdoor heat exchanger 15, there is a possibility that the refrigerant will radiate heat to the outside air in the outdoor heat exchanger 15. When the refrigerant radiates heat to the outside air in the outdoor heat exchanger 15, the amount of heat radiated by the refrigerant to the air in the water-refrigerant heat exchanger 13 decreases, and the heating capacity of the air decreases.

On the other hand, in the independent hot gas heating mode of this embodiment, the refrigerant circuit is switched to prevent the refrigerant flowing out from the water-refrigerant heat exchanger 13 from flowing into the outdoor heat exchanger 15. Heat radiation to the outside air can be suppressed.

Furthermore, in the independent hot gas heating mode of this embodiment, the opening degree of the cooling expansion valve 14c is controlled so that the degree of superheating SH of the suction refrigerant approaches the reference degree of superheating KSH. According to this, even if the amount of heat radiated from the discharged refrigerant to the high temperature side heat medium in the water-refrigerant heat exchanger 13 is increased by increasing the refrigerant discharge capacity of the compressor 11, the state of the suction refrigerant remains unchanged. It can be a gas phase refrigerant with a degree of superheat.

Therefore, in the independent hot gas heating mode, even if the outside temperature Tam is extremely low, the heat generated by the work of the compressor 11 is effectively used to heat the air, thereby realizing heating of the vehicle interior. be able to.

(d-2) Cooled hot gas heating mode In the cooled hot gas heating mode, the control device 60 controls the low temperature side heat medium circuit 40 so that a predetermined reference pumping capacity is exhibited compared to the independent hot gas heating mode. The low temperature side pump 41 is activated. Therefore, in the refrigeration cycle 10 in the cooling hot gas heating mode, the refrigerant flowing into the chiller 20 absorbs heat from the low temperature side heat medium. Thereby, the low temperature side heat medium is cooled. Other operations are similar to the independent hot gas heating mode.

Therefore, in the cooling hot gas heating mode, similarly to the independent hot gas heating mode, the heat generated by the work of the compressor 11 can be effectively used to heat the air, thereby realizing heating of the vehicle interior. can. Furthermore, in the low temperature side heat medium circuit 40 in the cooling hot gas heating mode, the low temperature side heat medium cooled by the chiller 20 flows through the cooling water passage 70a of the battery 70. Thereby, the battery 70 can be cooled.

(e) Hot gas dehumidification and heating mode The hot gas dehumidification and heating mode is an operation mode for dehumidifying and heating the vehicle interior. In the control program, the hot gas dehumidification/heating mode is selected when the outside temperature Tam is in a predetermined low-medium temperature range (in this embodiment, 0° C. or more and less than 10° C.).

The hot gas dehumidifying heating mode includes an independent hot gas dehumidifying heating mode and a cooling hot gas dehumidifying heating mode. The independent hot gas dehumidification/heating mode is an operation mode in which the interior of the vehicle is dehumidified and heated without cooling the battery 70. The cooling hot gas dehumidification/heating mode is an operation mode in which the battery 70 is cooled and the interior of the vehicle is dehumidified and heated.

(e-1) Independent hot gas dehumidification and heating mode In the refrigeration cycle 10 in the independent hot gas dehumidification and heating mode, the control device 60 fully closes the heating expansion valve 14a and throttles the cooling expansion valve 14b to cool the air. The expansion valve 14c is in a throttled state, and the bypass flow rate adjustment valve 14d is in a throttled state. Further, the control device 60 opens the dehumidification on-off valve 22a and closes the heating on-off valve 22b.

Therefore, in the refrigeration cycle 10 in the independent hot gas dehumidification heating mode, the refrigerant discharged from the compressor 11 circulates in the same manner as in the independent hot gas heating mode. At the same time, the refrigerant discharged from the compressor 11 is transferred to the first three-way joint 12a, the water-refrigerant heat exchanger 13, the dehumidification passage 21a, the cooling expansion valve 14b which is in a throttled state, the indoor evaporator 18, and the suction side passage. 21d, the refrigerant circuit is switched to a refrigerant circuit in which refrigerant is circulated in the order of the suction port of the compressor 11. That is, the indoor evaporator 18 and chiller 20 are switched to a refrigerant circuit connected in parallel to the flow of refrigerant.

Further, the control device 60 controls the refrigerant discharge capacity of the compressor 11 so that the suction refrigerant pressure Ps approaches a predetermined second target low pressure PSO2. The second target low pressure PSO2 is determined so that the refrigerant evaporation temperature in the indoor evaporator 18 becomes a temperature at which air can be dehumidified without causing frost formation on the indoor evaporator 18.

Moreover, the control device 60 controls the throttle opening degree of the bypass flow rate adjustment valve 14d so that the discharge refrigerant pressure Pd approaches the target high pressure PDO, similarly to the hot gas heating mode.

Further, the control device 60 controls the opening degree of the cooling expansion valve 14b so that the opening degree is a predetermined opening degree for the hot gas dehumidification/heating mode.

Further, the control device 60 controls the throttle opening degree of the cooling expansion valve 14c so that the superheat degree SH of the suction refrigerant approaches the reference superheat degree KSH.

Further, in the high temperature side heat medium circuit 30 in the independent hot gas dehumidification/heating mode, the control device 60 operates the high temperature side pump 31 similarly to the independent cooling mode.

Further, in the low temperature side heat medium circuit 40 in the independent hot gas dehumidification/heating mode, the control device 60 stops the low temperature side pump 41.

Further, in the indoor air conditioning unit 50 in the independent hot gas dehumidification heating mode, the control device 60 controls the air blowing capacity of the indoor blower 52 and the opening degree of the air mix door 54, similarly to the independent cooling mode. Furthermore, the control device 60 appropriately controls the operations of other controlled devices.

Therefore, in the refrigeration cycle 10 in the independent hot gas dehumidification/heating mode, the state of the refrigerant changes as described below.

The flow of the refrigerant discharged from the compressor 11 is branched at the first three-way joint 12a. One of the refrigerants branched off at the first three-way joint 12a flows into the water-refrigerant heat exchanger 13 and radiates heat to the high temperature side heat medium. Thereby, the high temperature side heat medium is heated.

The refrigerant flowing out from the water-refrigerant heat exchanger 13 flows into the dehumidification passage 21a. The flow of the refrigerant that has flowed into the dehumidification passage 21a passes through the fourth three-way joint 12d and is branched at the fifth three-way joint 12e. One of the refrigerants branched off at the fifth three-way joint 12e flows into the cooling expansion valve 14b and is depressurized.

The refrigerant whose pressure has been reduced by the cooling expansion valve 14b flows into the indoor evaporator 18. The refrigerant that has flowed into the indoor evaporator 18 exchanges heat with the air blown from the indoor blower 52 and evaporates. This cools and dehumidifies the air. The refrigerant flowing out of the indoor evaporator 18 flows into the second inlet of the four-way joint 12x via the evaporation pressure regulating valve 14e.

The other refrigerant branched at the fifth three-way joint 12e flows into the cooling expansion valve 14c and is depressurized. The refrigerant whose pressure is reduced by the cooling expansion valve 14c flows into the chiller 20. In the hot gas dehumidification heating mode, the low temperature side pump 41 is stopped, so there is no heat exchange between the refrigerant and the low temperature side heat medium in the chiller 20. The refrigerant flowing out of the chiller 20 flows into the third inlet of the four-way joint 12x.

At the four-way joint 12x, the flow of refrigerant flowing out from the indoor evaporator 18 and the flow of refrigerant flowing out from the chiller 20 join together. The refrigerant flowing out from the four-way joint 12x flows into the other inlet of the sixth three-way joint 12f.

Further, the other refrigerant branched at the first three-way joint 12a flows into the bypass passage 21c. The pressure of the refrigerant flowing into the bypass passage 21c is reduced when the flow rate is adjusted by the bypass flow rate adjustment valve 14d, similarly to the hot gas heating mode. The refrigerant whose pressure has been reduced by the bypass flow rate adjustment valve 14d flows into one inlet of the sixth three-way joint 12f.

The refrigerant flowing out from the four-way joint 12x and the refrigerant flowing out from the bypass flow rate adjustment valve 14d meet and mix at the sixth three-way joint 12f. The refrigerant flowing out from the sixth three-way joint 12f is mixed while flowing through the suction side passage 21d, and is sucked into the compressor 11.

Here, the pressure of the refrigerant reduced by the cooling expansion valve 14c may be lower than the pressure of the refrigerant reduced by the cooling expansion valve 14b, or the pressure of the refrigerant reduced by the cooling expansion valve 14b It may be a value higher than the pressure of the refrigerant, or it may be a value equivalent to the pressure of the refrigerant reduced in pressure by the cooling expansion valve 14b.

As described above, the refrigeration cycle 10 in the hot gas dehumidification heating mode uses refrigerants with different enthalpies, such as a low enthalpy refrigerant flowing out from the chiller 20, a high enthalpy refrigerant flowing out from the bypass passage 21c, and a refrigerant flowing out from the indoor evaporator 18. The refrigerant circuit is switched to a refrigerant circuit in which the refrigerant is mixed with each other and sucked into the compressor 11.

Therefore, in the refrigeration cycle 10 in the hot gas dehumidification/heating mode, the cooling expansion valve 14b and the cooling expansion valve 14c serve as a heating section side pressure reducing section.

Further, in the high temperature side heat medium circuit 30 in the independent hot gas dehumidifying heating mode, the high temperature side heat medium heated in the water refrigerant heat exchanger 13 flows into the heater core 32, as in the independent cooling mode. Further, in the indoor air conditioning unit 50 in the independent hot gas dehumidifying and heating mode, dehumidifying and heating the vehicle interior is achieved by blowing temperature-adjusted air into the vehicle interior, similarly to the individual series dehumidifying and heating mode.

Here, the independent hot gas dehumidification/heating mode is an operation mode in which air is cooled and dehumidified, and the dehumidified air is reheated to a desired temperature and blown into the vehicle interior. Therefore, in the independent hot gas dehumidification heating mode, the workload of the compressor 11 is adjusted so that the temperature of the air can be reheated to the desired temperature in the heating section without causing frost formation on the indoor evaporator 18. must be adjusted.

On the other hand, in the independent hot gas dehumidification/heating mode of this embodiment, a refrigerant with relatively high enthalpy is made to flow into the sixth three-way joint 12f via the bypass passage 21c. According to this, even if the refrigerant discharge capacity of the compressor 11 is increased, a decrease in the suction refrigerant pressure Ps can be suppressed. As a result, the amount of heat radiated from the discharged refrigerant to the high temperature side heat medium in the water-refrigerant heat exchanger 13 can be increased without causing frost formation on the indoor evaporator 18.

Therefore, in the independent hot gas dehumidification/heating mode, air can be heated with a higher heating capacity than in the series dehumidification/heating mode.

(e-2) Cooling hot gas dehumidifying and heating mode In the cooling hot gas dehumidifying and heating mode, the control device 60 controls the low temperature side pump 41 so as to exhibit a predetermined standard pumping capacity with respect to the independent hot gas dehumidifying and heating mode. Activate. Therefore, in the refrigeration cycle 10 in the cooling hot gas dehumidification/heating mode, the refrigerant flowing into the chiller 20 absorbs heat from the low temperature side heat medium. Thereby, the low temperature side heat medium is cooled. Other operations are similar to the independent hot gas dehumidification heating mode.

Therefore, in the cooling hot gas dehumidifying/heating mode, similarly to the independent hot gas dehumidifying/heating mode, air can be heated with a higher heating capacity than in the series dehumidifying/heating mode, thereby realizing dehumidifying/heating inside the vehicle interior. Further, in the low temperature side heat medium circuit 40 in the cooling hot gas dehumidification heating mode, the low temperature side heat medium cooled by the chiller 20 flows through the cooling water passage 70a of the battery 70. Thereby, the battery 70 can be cooled.

(f) Hot Gas Series Dehumidification and Heating Mode The hot gas series dehumidification and heating mode is an operation mode for dehumidifying and heating the vehicle interior. In the control program, when it is determined that the air heating capacity in the water-refrigerant heat exchanger 13 is insufficient in the serial dehumidifying heating mode, the hot gas serial dehumidifying heating mode is selected.

The hot gas series dehumidifying and heating mode includes an individual hot gas series dehumidifying and heating mode and a cooling hot gas series dehumidifying and heating mode. The independent hot gas series dehumidification/heating mode is an operation mode in which the interior of the vehicle is dehumidified and heated without cooling the battery 70. The cooling hot gas series dehumidifying and heating mode is an operation mode in which the battery 70 is cooled and the interior of the vehicle is dehumidified and heated.

(f-1) Independent Hot Gas Series Dehumidification Heating Mode In the refrigeration cycle 10 in the independent hot gas series dehumidification heating mode, the control device 60 sets the heating expansion valve 14a to the throttled state, and sets the cooling expansion valve 14b to the throttled state, The cooling expansion valve 14c is in a throttled state, and the bypass flow rate adjustment valve 14d is in a throttled state. Further, the control device 60 closes the dehumidification on-off valve 22a and closes the heating on-off valve 22b.

Therefore, in the refrigeration cycle 10 in the independent hot gas serial dehumidification/heating mode, the refrigerant discharged from the compressor 11 circulates in the same way as in the cooling series dehumidification/heating mode. At the same time, the refrigerant discharged from the compressor 11 is transferred to the first three-way joint 12a, the bypass flow regulating valve 14d in a throttled state arranged in the bypass passage 21c, the sixth three-way joint 12f, the suction side passage 21d, and the compressor. The refrigerant circuit is switched to circulate in the order of 11 suction ports.

Furthermore, the control device 60 controls the refrigerant discharge capacity of the compressor 11 so that the suction refrigerant pressure Ps approaches the predetermined second target low pressure PSO2, similarly to the hot gas dehumidification heating mode.

Moreover, the control device 60 controls the throttle opening degree of the bypass flow rate adjustment valve 14d so that the discharge refrigerant pressure Pd approaches the target high pressure PDO, similarly to the hot gas heating mode.

Further, the control device 60 controls the throttle opening degrees of the heating expansion valve 14a and the cooling expansion valve 14b so that the throttle opening degrees are set to the predetermined throttle opening degrees for the hot gas serial dehumidification heating mode.

Further, the control device 60 controls the throttle opening degree of the cooling expansion valve 14c so that the degree of superheating SH of the suction refrigerant approaches the reference degree of superheating KSH, similarly to the hot gas dehumidification/heating mode.

Further, in the high temperature side heat medium circuit 30 in the independent hot gas dehumidification/heating mode, the control device 60 operates the high temperature side pump 31 similarly to the independent cooling mode.

Further, in the low temperature side heat medium circuit 40 in the independent hot gas dehumidification/heating mode, the control device 60 stops the low temperature side pump 41.

Further, in the indoor air conditioning unit 50 in the independent hot gas dehumidification heating mode, the control device 60 controls the air blowing capacity of the indoor blower 52 and the opening degree of the air mix door 54, similarly to the independent cooling mode. Furthermore, the control device 60 appropriately controls the operations of other controlled devices.

Therefore, in the refrigeration cycle 10 in the single hot gas serial dehumidification/heating mode, the state of the refrigerant changes as described below.

The flow of the refrigerant discharged from the compressor 11 is branched at the first three-way joint 12a. One of the refrigerants branched off at the first three-way joint 12a flows into the water-refrigerant heat exchanger 13 and radiates heat to the high temperature side heat medium. Thereby, the high temperature side heat medium is heated.

The refrigerant flowing out from the water-refrigerant heat exchanger 13 flows into the heating expansion valve 14a and is depressurized. The refrigerant whose pressure has been reduced by the heating expansion valve 14a flows into the outdoor heat exchanger 15. The refrigerant flowing into the outdoor heat exchanger 15 exchanges heat with the outside air to reduce enthalpy.

The flow of the refrigerant flowing out from the outdoor heat exchanger 15 passes through the third three-way joint 12c and the fourth three-way joint 12d, and is branched at the fifth three-way joint 12e. One of the refrigerants branched off at the fifth three-way joint 12e flows into the cooling expansion valve 14b and is depressurized.

The refrigerant whose pressure has been reduced by the cooling expansion valve 14b flows into the indoor evaporator 18, exchanges heat with the air blown from the indoor blower 52, and evaporates, similarly to the hot gas dehumidification/heating mode. This cools and dehumidifies the air. The refrigerant flowing out of the indoor evaporator 18 flows into the second inlet of the four-way joint 12x via the evaporation pressure regulating valve 14e.

The other refrigerant branched at the fifth three-way joint 12e flows into the cooling expansion valve 14c and is depressurized, similarly to the hot gas heating mode. The refrigerant whose pressure is reduced by the cooling expansion valve 14c flows into the chiller 20. The refrigerant flowing out of the chiller 20 flows into the third inlet of the four-way joint 12x.

At the four-way joint 12x, similarly to the hot gas heating mode, the flow of refrigerant flowing out from the indoor evaporator 18 and the flow of refrigerant flowing out from the chiller 20 merge. The refrigerant flowing out from the four-way joint 12x flows into the other inlet of the sixth three-way joint 12f.

Further, the other refrigerant branched at the first three-way joint 12a flows into the bypass passage 21c. The pressure of the refrigerant flowing into the bypass passage 21c is reduced when the flow rate is adjusted by the bypass flow rate adjustment valve 14d, similarly to the hot gas heating mode. The refrigerant whose pressure has been reduced by the bypass flow rate adjustment valve 14d flows into one inlet of the sixth three-way joint 12f.

The refrigerant flowing out from the four-way joint 12x and the refrigerant flowing out from the bypass flow rate adjustment valve 14d join and mix at the sixth three-way joint 12f, similarly to the hot gas dehumidification heating mode. The refrigerant flowing out from the sixth three-way joint 12f is mixed while flowing through the suction side passage 21d, and is sucked into the compressor 11.

Here, the pressure of the refrigerant reduced by the cooling expansion valve 14c may be lower than the pressure of the refrigerant reduced by the cooling expansion valve 14b, or the pressure of the refrigerant reduced by the cooling expansion valve 14b It may be a value higher than the pressure of the refrigerant, or it may be a value equivalent to the pressure of the refrigerant reduced in pressure by the cooling expansion valve 14b.

As described above, the refrigeration cycle 10 in the hot gas series dehumidification heating mode uses a refrigerant with different enthalpies, such as a low enthalpy refrigerant flowing out from the chiller 20, a high enthalpy refrigerant flowing out from the bypass passage 21c, and a refrigerant flowing out from the indoor evaporator 18. The refrigerant circuit is switched to a refrigerant circuit that mixes refrigerants and causes them to be sucked into the compressor 11.

Therefore, in the refrigeration cycle 10 in the hot gas serial dehumidification/heating mode, the heating expansion valve 14a, the cooling expansion valve 14b, and the cooling expansion valve 14c serve as a heating section side pressure reducing section.

Further, in the high temperature side heat medium circuit 30 in the independent hot gas series dehumidifying heating mode, the high temperature side heat medium heated in the water refrigerant heat exchanger 13 flows into the heater core 32, as in the independent cooling mode.

Further, in the indoor air conditioning unit 50 in the independent hot gas series dehumidifying heating mode, dehumidifying and heating the vehicle interior is achieved by blowing temperature-adjusted air into the vehicle interior, similarly to the individual serial dehumidifying heating mode.

Here, in the hot gas series dehumidifying heating mode, as in the hot gas dehumidifying heating mode, the temperature of the air can be reheated to a desired temperature in the heating section without causing frost formation on the indoor evaporator 18. Therefore, the refrigerant discharge capacity of the compressor 11 must be adjusted.

Furthermore, in the independent hot gas series dehumidification/heating mode of this embodiment, a refrigerant with relatively high enthalpy is made to flow into the sixth three-way joint 12f via the bypass passage 21c. According to this, as in the independent hot gas series dehumidification heating mode, even if the refrigerant discharge capacity of the compressor 11 is increased, the refrigerant is discharged in the water-refrigerant heat exchanger 13 without causing frost formation on the indoor evaporator 18. The amount of heat radiated from the refrigerant to the air can be increased.

As a result, in the single hot gas series dehumidifying and heating mode, air can be heated with a higher heating capacity than in the series dehumidifying and heating mode.

(f-2) Cooling hot gas series dehumidifying heating mode In the cooling hot gas series dehumidifying heating mode, the control device 60 controls the low temperature so as to exhibit a predetermined standard pumping capacity compared to the individual hot gas series dehumidifying heating mode. Activate the side pump 41. Therefore, in the refrigeration cycle 10 in the cooling hot gas serial dehumidification/heating mode, the refrigerant flowing into the chiller 20 absorbs heat from the low temperature side heat medium. Thereby, the low temperature side heat medium is cooled. Other operations are similar to the independent hot gas series dehumidification heating mode.

Therefore, in the cooling hot gas series dehumidifying and heating mode, similarly to the single hot gas series dehumidifying and heating mode, air can be heated with a higher heating capacity than in the series dehumidifying and heating mode, and dehumidifying and heating in the vehicle interior can be realized. Further, in the low temperature side heat medium circuit 40 in the cooling hot gas dehumidification heating mode, the low temperature side heat medium cooled by the chiller 20 flows through the cooling water passage 70a of the battery 70. Thereby, the battery 70 can be cooled.

As described above, in the vehicle air conditioner 1 of the present embodiment, by switching the driving mode, comfortable air conditioning in the vehicle interior and appropriate temperature adjustment of the battery 70, which is an on-vehicle device, can be performed.

The reliability determination of each pressure sensor in each of the above-mentioned operation modes will be explained. The control device 60 determines the reliability of the two pressure sensors by monitoring the detection values of two of the pressure sensors during operation of the refrigeration cycle 10. That is, it is determined whether there is a possibility that at least one of the two pressure sensors is malfunctioning. Therefore, the control device 60 is a determination unit that determines the reliability of the detected value of the pressure sensor.

First, reliability determination of the discharge refrigerant pressure sensor 62a and the outdoor unit refrigerant pressure sensor 62b will be described. The discharge refrigerant pressure sensor 62a and the outdoor unit refrigerant pressure sensor 62b are monitored from the differential pressure between the inlet and outlet of the heating expansion valve 14a. The differential pressure between the inlet and outlet of the heating expansion valve 14a is the pressure difference obtained by subtracting the refrigerant pressure on the refrigerant outlet side of the heating expansion valve 14a from the refrigerant pressure on the refrigerant inlet side of the heating expansion valve 14a.

The control device 60 determines that the value of the differential pressure obtained by subtracting the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b from the discharge refrigerant pressure Pd detected by the discharge refrigerant pressure sensor 62a is the inlet/outlet of the heating expansion valve 14a. If the differential pressure between the two is close to the value, it is determined that the discharge refrigerant pressure sensor 62a and the outdoor unit refrigerant pressure sensor 62b are reliable.

The control device 60 determines that the value of the differential pressure obtained by subtracting the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b from the discharge refrigerant pressure Pd detected by the discharge refrigerant pressure sensor 62a is the inlet/outlet of the heating expansion valve 14a. If the pressure difference deviates significantly from the value of the differential pressure between them, at least one pressure sensor among the discharge refrigerant pressure sensor 62a and the outdoor unit refrigerant pressure sensor 62b is unreliable, that is, the discharge refrigerant pressure sensor 62a and the outdoor unit refrigerant pressure sensor 62b. It is determined that at least one of the pressure sensors is likely to be malfunctioning.

The control device 60 estimates the differential pressure between the inlet and outlet of the heating expansion valve 14a using the characteristic diagram shown in FIG. 5 based on the power consumption value of the electric actuator that displaces the valve body of the heating expansion valve 14a. do.

The characteristic diagram shown in FIG. 5 will be explained. As shown in FIG. 6, there is a proportional relationship between the pressure difference between the inlet side and the outlet side of the valve body of the heating expansion valve 14a and the torque applied to the electric actuator.

This is because there is a relationship of "force received by the valve body = pressure receiving area x pressure difference", the relationship between force and torque in the rotation/linear conversion mechanism is proportional, and the reduction mechanism connected to the electric actuator. This can be said because the relationship between input and output torque is proportional.

In the heating expansion valve 14a, if a sealing member is not provided between the deceleration mechanism and the rotation-to-direct motion conversion mechanism (hereinafter referred to as the power transmission mechanism) to prevent refrigerant from entering, the power transmission mechanism may contain refrigerating machine oil. invades. As shown by the dashed line in FIG. 6, the higher the temperature of the refrigerating machine oil, the lower the friction of the power transmission mechanism. This characteristic can be alleviated if a seal member is provided to prevent the power transmission mechanism from being immersed in the refrigerant. This characteristic can also be reduced if a non-contact type deceleration/transmission mechanism such as a magnetic gear is provided.

As shown in FIG. 7, the torque and current of the electric actuator are in a proportional relationship. This is due to the characteristics of brushless motors. The torque generated by the motor has a characteristic that the higher the temperature, the lower the torque is due to the effect of demagnetization of the permanent magnet.

From the two relationships shown in FIGS. 6 and 7 and the characteristic diagram shown in FIG. 5, the differential pressure between the inlet and outlet of the heating expansion valve 14a can be estimated based on the power consumption value of the motor electric actuator.

Although it depends on the structure of the power transmission mechanism, the friction reduction effect due to high temperature and the torque reduction due to demagnetization due to high temperature cancel each other out, and the error in estimating the valve differential pressure due to temperature is reduced. reference). If the error is to be made as small as possible, it is also possible to correct it by measuring in advance the torque reduction effect due to demagnetization caused by temperature and the amount of friction increase in the power transmission mechanism.

A method for acquiring the power consumption value of the electric actuator of the heating expansion valve 14a when estimating the differential pressure between the inlet and outlet of the heating expansion valve 14a will be described. When the control device 60 operates the electric actuator of the heating expansion valve 14a to control the refrigeration cycle 10, the control device 60 operates to eliminate the deviation between the current rotor position and the target rotor position of the electric actuator. Controls the energization of the electric actuator. The average value of the current values required at this time is acquired as the power consumption value of the electric actuator. This is because the average value of the current value required at this time is proportional to the torque of the electric actuator.

On the other hand, if the control device 60 does not need to operate the electric actuator of the heating expansion valve 14a to control the refrigeration cycle 10, the heating The energization of the electric actuator of the expansion valve 14a is controlled so that the electric actuator of the expansion valve 14a is operated only to the minimum extent necessary. The average value of the current values required at this time is acquired as the power consumption value of the electric actuator.

The power consumption value of the electric actuator may be estimated and acquired from values such as the maximum value and duty ratio of the current waveform used in the energization control of the electric actuator.

The control device 60 estimates the differential pressure between the inlet and outlet of the heating expansion valve 14a based on the power consumption value of the electric actuator acquired in this way.

The target value of the current applied to the coil of the electric actuator is determined by a feedback loop, but the higher the load torque of the valve mechanism connected to the rotor of the electric actuator, the slower the rotor movement position and speed at the same current tend to be. There is a characteristic that the control current value required to return to the target position increases.

In this embodiment, we focus on the characteristic that the driving load of the valve (in other words, the rotor load torque of the electric actuator) is proportional to the coil current controlled by the inverter, and use information about the working current value of the current controlled by the inverter. First, calculate the driving load of the valve.

When the pressure difference between the inlet and outlet of the valve is dP, and the pressure receiving area of the valve is A, the driving load of the valve has a relationship of dP×A. This is because "dimension of pressure=force/area", so the driving load is proportional to dP×A.

The driving load of the valve is the sum of the load on the valve body due to the differential pressure and the friction of mechanical power transmission parts such as the reduction mechanism and the rotational linear motion conversion mechanism, and this becomes the operating torque of the electric actuator.

Valve driving load From the relationship that the valve load is proportional to dP×A, it can be said that the differential pressure dP between the inlet and outlet of the valve is proportional to "valve driving load/A." The pressure receiving area of the valve body can be easily determined from the structure of the valve, and can also be determined experimentally.

Therefore, by calculating the driving load of the valve from the operating current, "valve driving load/A" can be calculated, and the differential pressure dP between the inlet and outlet of the valve can be estimated.

Next, reliability determination of the discharge refrigerant pressure sensor 62a and the evaporator refrigerant pressure sensor 62c will be described. The discharge refrigerant pressure sensor 62a and the evaporator refrigerant pressure sensor 62c measure the differential pressure between the inlet and outlet of the heating expansion valve 14a, the differential pressure between the inlet and outlet of the cooling expansion valve 14b, and the pressure loss in the indoor evaporator 18. is monitored from the total value of

The pressure difference between the inlet and outlet of the cooling expansion valve 14b can be estimated using the same method as the method for estimating the pressure difference between the inlet and outlet of the heating expansion valve 14a.

The pressure loss in the indoor evaporator 18 can be estimated from the refrigerant flow rate in the indoor evaporator 18. The refrigerant flow rate in the indoor evaporator 18 can be estimated by multiplying the discharge refrigerant flow rate of the compressor 11 by the opening area ratio of the cooling expansion valve 14b and the cooling expansion valve 14c. The discharge flow rate of refrigerant from the compressor 11 can be estimated from a control signal output from the control device 60 to the compressor 11. The opening area of the cooling expansion valve 14b can be estimated from a control signal output from the control device 60 to the cooling expansion valve 14b. The opening area of the cooling expansion valve 14c can be estimated from a control signal output from the control device 60 to the cooling expansion valve 14c.

The control device 60 determines that the value of the differential pressure obtained by subtracting the evaporator refrigerant pressure Pe detected by the evaporator refrigerant pressure sensor 62c from the discharge refrigerant pressure Pd detected by the discharge refrigerant pressure sensor 62a is the difference between the inlet and outlet of the heating expansion valve 14a. , the differential pressure between the inlet and outlet of the cooling expansion valve 14b, and the pressure loss in the indoor evaporator 18 are close to the total value, the discharge refrigerant pressure sensor 62a and the evaporator refrigerant pressure sensor 62c are reliable to decide.

The control device 60 determines that the value of the differential pressure obtained by subtracting the evaporator refrigerant pressure Pe detected by the evaporator refrigerant pressure sensor 62c from the discharge refrigerant pressure Pd detected by the discharge refrigerant pressure sensor 62a is the difference between the inlet and outlet of the heating expansion valve 14a. , the differential pressure between the inlet and outlet of the cooling expansion valve 14b, and the pressure loss in the indoor evaporator 18. It is determined that at least one of the pressure sensors is unreliable, that is, it is highly likely that at least one of the discharge refrigerant pressure sensor 62a and the evaporator refrigerant pressure sensor 62c is out of order.

Next, reliability determination of the discharge refrigerant pressure sensor 62a and the chiller refrigerant pressure sensor 62d will be described. The discharge refrigerant pressure sensor 62a and the chiller refrigerant pressure sensor 62d measure the total value of the differential pressure between the inlet and outlet of the heating expansion valve 14a, the differential pressure between the inlet and outlet of the cooling expansion valve 14c, and the pressure loss in the chiller 20. be monitored from

The pressure difference between the inlet and outlet of the cooling expansion valve 14c can be estimated using the same method as the method for estimating the pressure difference between the inlet and outlet of the heating expansion valve 14a.

The pressure loss in the chiller 20 can be estimated from the refrigerant flow rate in the chiller 20. The refrigerant flow rate in the chiller 20 can be estimated by multiplying the discharge refrigerant flow rate of the compressor 11 by the opening area ratio of the cooling expansion valve 14c and the cooling expansion valve 14b.

The control device 60 determines that the value of the differential pressure obtained by subtracting the chiller refrigerant pressure Pc detected by the chiller refrigerant pressure sensor 62d from the discharge refrigerant pressure Pd detected by the discharge refrigerant pressure sensor 62a is the difference between the inlet and outlet of the heating expansion valve 14a. If the pressure is close to the total value of the differential pressure between the inlet and outlet of the cooling expansion valve 14b and the pressure loss in the chiller 20, it is determined that the discharge refrigerant pressure sensor 62a and the chiller refrigerant pressure sensor 62d are reliable.

The control device 60 determines that the value of the differential pressure obtained by subtracting the chiller refrigerant pressure Pc detected by the chiller refrigerant pressure sensor 62d from the discharge refrigerant pressure Pd detected by the discharge refrigerant pressure sensor 62a is the difference between the inlet and outlet of the heating expansion valve 14a. If the total value of the pressure, the differential pressure between the inlet and outlet of the cooling expansion valve 14b, and the pressure loss in the chiller 20 deviates significantly, at least one of the discharge refrigerant pressure sensor 62a and the chiller refrigerant pressure sensor 62d It is determined that the pressure sensors are unreliable, that is, it is highly likely that at least one of the discharge refrigerant pressure sensor 62a and the chiller refrigerant pressure sensor 62d is out of order.

Next, reliability determination of the discharge refrigerant pressure sensor 62a and the suction refrigerant pressure sensor 62e will be explained. The discharge refrigerant pressure sensor 62a and the suction refrigerant pressure sensor 62e are monitored from the differential pressure between the inlet and outlet of the bypass flow rate adjustment valve 14d when the bypass flow rate adjustment valve 14d is opened.

The pressure difference between the inlet and outlet of the bypass flow rate adjustment valve 14d can be estimated using the same method as the method for estimating the pressure difference between the inlet and outlet of the heating expansion valve 14a.

The control device 60 determines that the value of the differential pressure obtained by subtracting the suction refrigerant pressure Ps detected by the suction refrigerant pressure sensor 62e from the discharge refrigerant pressure Pd detected by the discharge refrigerant pressure sensor 62a is the differential pressure between the inlet and outlet of the bypass flow rate adjustment valve 14d. If it is close to , it is determined that the discharge refrigerant pressure sensor 62a and the suction refrigerant pressure sensor 62e are reliable.

The control device 60 determines that the value of the differential pressure obtained by subtracting the suction refrigerant pressure Ps detected by the suction refrigerant pressure sensor 62e from the discharge refrigerant pressure Pd detected by the discharge refrigerant pressure sensor 62a is the differential pressure between the inlet and outlet of the bypass flow rate adjustment valve 14d. If there is a large deviation from the pressure sensor, at least one of the discharge refrigerant pressure sensor 62a and the suction refrigerant pressure sensor 62e is unreliable. It is determined that there is a high possibility that the device is malfunctioning.

Next, reliability determination of the outdoor unit refrigerant pressure sensor 62b and the evaporator refrigerant pressure sensor 62c will be described. The outdoor unit refrigerant pressure sensor 62b and the evaporator refrigerant pressure sensor 62c are monitored from the total value of the differential pressure between the inlet and outlet of the cooling expansion valve 14b and the pressure loss in the indoor evaporator 18.

The control device 60 determines that the value of the differential pressure obtained by subtracting the evaporator refrigerant pressure Pe detected by the evaporator refrigerant pressure sensor 62c from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b is the value of the differential pressure of the cooling expansion valve 14b. If the differential pressure between the inlet and outlet is close to the total value of the pressure loss in the indoor evaporator 18, it is determined that the outdoor unit refrigerant pressure sensor 62b and the evaporator refrigerant pressure sensor 62c are reliable.

The control device 60 determines that the value of the differential pressure obtained by subtracting the evaporator refrigerant pressure Pe detected by the evaporator refrigerant pressure sensor 62c from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b is the value of the differential pressure of the cooling expansion valve 14b. If the differential pressure between the inlet and outlet deviates significantly from the total value of the pressure loss in the indoor evaporator 18, at least one of the outdoor unit refrigerant pressure sensor 62b and the evaporator refrigerant pressure sensor 62c is unreliable. That is, it is determined that at least one of the outdoor unit refrigerant pressure sensor 62b and the evaporator refrigerant pressure sensor 62c is likely to be malfunctioning.

Next, reliability determination of the outdoor unit refrigerant pressure sensor 62b and the evaporator refrigerant pressure sensor 62c will be described. When the cooling expansion valve 14b is closed, the outdoor unit refrigerant pressure sensor 62b and the evaporator refrigerant pressure sensor 62c measure the differential pressure between the inlet and outlet of the heating on-off valve 22b and the inlet and outlet of the evaporation pressure regulating valve 14e. It is monitored from the total value of the differential pressure.

The differential pressure between the inlet and outlet of the heating on-off valve 22b and the differential pressure between the inlet and outlet of the evaporation pressure regulating valve 14e can be estimated using the same method as the method for estimating the differential pressure between the inlet and outlet of the heating expansion valve 14a.

The control device 60 determines that the value of the differential pressure obtained by subtracting the evaporator refrigerant pressure Pe detected by the evaporator refrigerant pressure sensor 62c from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b is the value of the differential pressure of the heating on-off valve 22b. If the differential pressure between the inlet and outlet is close to the total value of the differential pressure between the inlet and outlet of the evaporation pressure regulating valve 14e, it is determined that the outdoor unit refrigerant pressure sensor 62b and the evaporator refrigerant pressure sensor 62c are reliable.

The control device 60 determines that the value of the differential pressure obtained by subtracting the evaporator refrigerant pressure Pe detected by the evaporator refrigerant pressure sensor 62c from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b is the value of the differential pressure of the heating on-off valve 22b. If the differential pressure between the inlet and outlet deviates significantly from the total value of the differential pressure between the inlet and outlet of the evaporation pressure regulating valve 14e, at least one of the outdoor unit refrigerant pressure sensor 62b and the evaporator refrigerant pressure sensor 62c It is determined that the pressure sensors are unreliable, that is, it is highly likely that at least one of the outdoor unit refrigerant pressure sensor 62b and the evaporator refrigerant pressure sensor 62c is malfunctioning.

Next, reliability determination of the outdoor unit refrigerant pressure sensor 62b and the chiller refrigerant pressure sensor 62d will be described. The outdoor unit refrigerant pressure sensor 62b and the chiller refrigerant pressure sensor 62d are monitored from the total value of the differential pressure between the inlet and outlet of the cooling expansion valve 14c and the pressure loss in the chiller 20.

The control device 60 determines the value of the differential pressure obtained by subtracting the chiller refrigerant pressure Pc detected by the chiller refrigerant pressure sensor 62d from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b, as the inlet/outlet of the heating on-off valve 22b. If the differential pressure between the two and the differential pressure between the inlet and the outlet of the evaporation pressure regulating valve 14e is close to the total value, it is determined that the outdoor unit refrigerant pressure sensor 62b and the chiller refrigerant pressure sensor 62d are reliable.

The control device 60 calculates the value of the differential pressure between the inlet and outlet of the cooling expansion valve 14c by subtracting the chiller refrigerant pressure Pc detected by the chiller refrigerant pressure sensor 62d from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b. If there is a large deviation from the total value of the differential pressure of It is determined that at least one pressure sensor among the sensor 62b and the chiller refrigerant pressure sensor 62d is likely to be malfunctioning.

The outdoor unit refrigerant pressure sensor 62b and the chiller refrigerant pressure sensor 62d are monitored from the value of the differential pressure between the inlet and outlet of the heating on-off valve 22b when the cooling expansion valve 14c is closed.

The control device 60 determines the value of the differential pressure obtained by subtracting the chiller refrigerant pressure Pc detected by the chiller refrigerant pressure sensor 62d from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b, as the inlet/outlet of the heating on-off valve 22b. If the differential pressure is close to the value between the two, it is determined that the outdoor unit refrigerant pressure sensor 62b and the chiller refrigerant pressure sensor 62d are reliable.

The control device 60 determines the value of the differential pressure obtained by subtracting the chiller refrigerant pressure Pc detected by the chiller refrigerant pressure sensor 62d from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b, as the inlet/outlet of the heating on-off valve 22b. If there is a large deviation from the value of the differential pressure between the It is determined that at least one of the pressure sensors is likely to be malfunctioning.

Next, reliability determination of the outdoor unit refrigerant pressure sensor 62b and the suction refrigerant pressure sensor 62e will be described. The outdoor unit refrigerant pressure sensor 62b and the suction refrigerant pressure sensor 62e are monitored from the value of the differential pressure between the inlet and outlet of the bypass flow rate adjustment valve 14d when the bypass flow rate adjustment valve 14d is opened.

The pressure difference between the inlet and outlet of the bypass flow rate adjustment valve 14d can be estimated using the same method as the method for estimating the pressure difference between the inlet and outlet of the heating expansion valve 14a.

The control device 60 determines that the value of the differential pressure obtained by subtracting the suction refrigerant pressure Ps detected by the suction refrigerant pressure sensor 62e from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b is determined between the inlet and outlet of the bypass flow rate adjustment valve 14d. If the differential pressure is close to the value of , it is determined that the outdoor unit refrigerant pressure sensor 62b and the suction refrigerant pressure sensor 62e are reliable.

The control device 60 determines that the value of the differential pressure obtained by subtracting the suction refrigerant pressure Ps detected by the suction refrigerant pressure sensor 62e from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b is determined between the inlet and outlet of the bypass flow rate adjustment valve 14d. If the pressure difference deviates significantly from the value of the differential pressure, at least one of the outdoor unit refrigerant pressure sensor 62b and the suction refrigerant pressure sensor 62e is unreliable. It is determined that at least one of the pressure sensors is likely to be malfunctioning.

When the cooling expansion valve 14b is opened, the outdoor unit refrigerant pressure sensor 62b and the suction refrigerant pressure sensor 62e detect the difference between the inlet and outlet of the cooling expansion valve 14b and the inlet and outlet of the evaporation pressure regulating valve 14e. It is monitored from the total value with the differential pressure.

The control device 60 determines the value of the differential pressure obtained by subtracting the suction refrigerant pressure Ps detected by the suction refrigerant pressure sensor 62e from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b, at the inlet and outlet of the cooling expansion valve 14b. If the differential pressure between the two and the differential pressure between the inlet and the outlet of the evaporation pressure regulating valve 14e are close to the total value, it is determined that the outdoor unit refrigerant pressure sensor 62b and the suction refrigerant pressure sensor 62e are reliable.

The control device 60 determines the value of the differential pressure obtained by subtracting the suction refrigerant pressure Ps detected by the suction refrigerant pressure sensor 62e from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b, at the inlet and outlet of the cooling expansion valve 14b. If there is a large deviation from the total value of the differential pressure between In other words, it is determined that at least one of the outdoor unit refrigerant pressure sensor 62b and the suction refrigerant pressure sensor 62e is likely to be malfunctioning.

The outdoor unit refrigerant pressure sensor 62b and the suction refrigerant pressure sensor 62e are monitored from the value of the differential pressure between the inlet and outlet of the cooling expansion valve 14c when the cooling expansion valve 14c is opened.

The control device 60 determines that a differential pressure value obtained by subtracting the suction refrigerant pressure Ps detected by the suction refrigerant pressure sensor 62e from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b is determined as the inlet/outlet of the cooling expansion valve 14c. If the differential pressure between the two is close to the value, it is determined that the outdoor unit refrigerant pressure sensor 62b and the suction refrigerant pressure sensor 62e are reliable.

The control device 60 determines that a differential pressure value obtained by subtracting the suction refrigerant pressure Ps detected by the suction refrigerant pressure sensor 62e from the outdoor unit side refrigerant pressure P2 detected by the outdoor unit refrigerant pressure sensor 62b is determined as the inlet/outlet of the cooling expansion valve 14c. If there is a large deviation from the value of the differential pressure between the two, at least one of the outdoor unit refrigerant pressure sensor 62b and the suction refrigerant pressure sensor 62e is unreliable, that is, the outdoor unit refrigerant pressure sensor 62b and the suction refrigerant pressure sensor 62e. It is determined that at least one of the pressure sensors is likely to be malfunctioning.

Next, reliability determination of the evaporator refrigerant pressure sensor 62c and the chiller refrigerant pressure sensor 62d will be described. The evaporator refrigerant pressure sensor 62c and the chiller refrigerant pressure sensor 62d are monitored from the value of the differential pressure between the inlet and outlet of the evaporation pressure regulating valve 14e.

The control device 60 determines that the value of the differential pressure obtained by subtracting the chiller refrigerant pressure Pc detected by the chiller refrigerant pressure sensor 62d from the evaporator refrigerant pressure Pe detected by the evaporator refrigerant pressure sensor 62c is determined between the inlet and outlet of the evaporation pressure regulating valve 14e. If the pressure difference is close to the value of the differential pressure, it is determined that the evaporator refrigerant pressure sensor 62c and the chiller refrigerant pressure sensor 62d are reliable.

The control device 60 determines that the value of the differential pressure obtained by subtracting the chiller refrigerant pressure Pc detected by the chiller refrigerant pressure sensor 62d from the evaporator refrigerant pressure Pe detected by the evaporator refrigerant pressure sensor 62c is determined between the inlet and outlet of the evaporation pressure regulating valve 14e. If the pressure difference deviates significantly from the value of the differential pressure, at least one of the evaporator refrigerant pressure sensor 62c and the chiller refrigerant pressure sensor 62d is unreliable. It is determined that at least one pressure sensor is likely to be malfunctioning.

Next, reliability determination of the evaporator refrigerant pressure sensor 62c and the suction refrigerant pressure sensor 62e will be described. The evaporator refrigerant pressure sensor 62c and the suction refrigerant pressure sensor 62e are monitored from the value of the differential pressure between the inlet and outlet of the evaporator pressure regulating valve 14e.

The control device 60 determines that the value of the differential pressure obtained by subtracting the suction refrigerant pressure Ps detected by the suction refrigerant pressure sensor 62e from the evaporator refrigerant pressure Pe detected by the evaporator refrigerant pressure sensor 62c is determined between the inlet and outlet of the evaporation pressure regulating valve 14e. If the pressure difference is close to the value of the differential pressure, it is determined that the evaporator refrigerant pressure sensor 62c and the suction refrigerant pressure sensor 62e are reliable.

The control device 60 determines that the value of the differential pressure obtained by subtracting the suction refrigerant pressure Ps detected by the suction refrigerant pressure sensor 62e from the evaporator refrigerant pressure Pe detected by the evaporator refrigerant pressure sensor 62c is determined between the inlet and outlet of the evaporation pressure regulating valve 14e. If there is a large deviation from the value of the differential pressure, at least one of the evaporator refrigerant pressure sensor 62c and the suction refrigerant pressure sensor 62e is unreliable. It is determined that at least one pressure sensor is likely to be malfunctioning.

Next, reliability determination of the chiller refrigerant pressure sensor 62d and the suction refrigerant pressure sensor 62e will be described. The chiller refrigerant pressure sensor 62d and the suction refrigerant pressure sensor 62e are monitored from each other's detected values.

When the value of the chiller refrigerant pressure Pc detected by the chiller refrigerant pressure sensor 62d and the value of the suction refrigerant pressure Ps detected by the suction refrigerant pressure sensor 62e are close, the control device 60 controls the chiller refrigerant pressure sensor 62d and the suction refrigerant pressure sensor 62e. judged to be reliable.

When the value of the chiller refrigerant pressure Pc detected by the chiller refrigerant pressure sensor 62d and the value of the suction refrigerant pressure Ps detected by the suction refrigerant pressure sensor 62e are significantly different from each other, the control device 60 controls the chiller refrigerant pressure sensor 62d and the suction refrigerant pressure sensor 62d. It is determined that at least one of the refrigerant pressure sensors 62e is unreliable, that is, it is highly likely that at least one of the chiller refrigerant pressure sensor 62d and the suction refrigerant pressure sensor 62e is malfunctioning.

As can be seen from the above explanation, the pressure detected by the pressure sensor on the upstream side of the expansion valve etc. (in other words, the upstream pressure sensor) and the pressure sensor on the downstream side of the expansion valve etc. (in other words, the downstream pressure sensor) Whether the difference in value is close to the total value of the differential pressure between the inlet and outlet of the expansion valve, etc. between the two pressure sensors, and the pressure loss of the heat exchanger, etc. between the two pressure sensors. It can be determined whether the two pressure sensors are reliable or not.

If it is determined that at least one of the two pressure sensors is unreliable, the control device 60 may, for example, stop the compressor 11, turn on an indicator that indicates an abnormal condition, or send a message to the vehicle's fault diagnosis device. Send malfunction information.

In this embodiment, the control device 60 estimates the differential pressure between the refrigerant inlet and outlet of the electric expansion valve from the operating current of the electric expansion valve located between two pressure sensors, and estimates the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. The reliability of the detected values of the two pressure sensors is determined based on the differential pressure between them.

According to this, the reliability of the detection values of the two pressure sensors is determined based on the differential pressure between the refrigerant inlet and outlet of the electric expansion valve, so the reliability of the detection values of the two pressure sensors is determined when the compressor is operating. can.

In this embodiment, the control device 60 estimates that the greater the operating current of the electric expansion valve, the greater the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. According to this, the differential pressure between the refrigerant inlet and outlet of the electric expansion valve can be appropriately estimated using the characteristic that the driving load of the valve is proportional to the operating current.

In this embodiment, the control device 60 stops the operation of the compressor 11 when determining that the detected value of at least one of the two pressure sensors is unreliable. Thereby, it is possible to avoid abnormal operation of the refrigeration cycle 10 when the detection value of the pressure sensor is unreliable.

(Second embodiment)
In the above embodiment, the reliability of each pressure sensor is determined using the differential pressure between the inlet and outlet of the expansion valve, etc., but in this embodiment, the difference between the detected value by a predetermined pressure sensor and the inlet and outlet of the expansion valve, etc. The number of pressure sensors is reduced by estimating a refrigerant pressure value corresponding to the refrigerant detection value of the other pressure sensor in the above embodiment using the differential pressure.

In the following, first to tenth embodiments will be described as examples of combinations of pressure sensors that use detected values and pressure sensors that reduce the number of detected values.

(First example)
In this embodiment, the outdoor unit refrigerant pressure sensor 62b is reduced using the detected value by the discharge refrigerant pressure sensor 62a and the differential pressure between the inlet and outlet of the heating expansion valve 14a.

That is, the refrigerant pressure value corresponding to the value detected by the outdoor unit refrigerant pressure sensor 62b is estimated using the value detected by the discharge refrigerant pressure sensor 62a and the differential pressure between the inlet and outlet of the heating expansion valve 14a.

Specifically, the total value of the detected value by the discharge refrigerant pressure sensor 62a, the differential pressure between the inlet and outlet of the heating expansion valve 14a, and the pressure loss of the water-refrigerant heat exchanger 13 and the outdoor heat exchanger 15 is It is estimated that the refrigerant pressure value corresponds to the value detected by the refrigerant pressure sensor 62b.

In the case of the operation mode in which the heating expansion valve 14a is closed, it is estimated that the saturation pressure value of the refrigerant corresponding to the ambient temperature of the outdoor heat exchanger 15 is the refrigerant pressure value corresponding to the detected value of the outdoor unit refrigerant pressure sensor 62b. do.

(Second example)
In this embodiment, the evaporator refrigerant pressure sensor 62c is reduced using the value detected by the discharge refrigerant pressure sensor 62a and the differential pressure between the inlet and outlet of the heating expansion valve 14a and the cooling expansion valve 14b.

That is, the refrigerant pressure value corresponding to the detection value of the evaporator refrigerant pressure sensor 62c is determined using the detection value of the discharge refrigerant pressure sensor 62a and the differential pressure between the inlets and outlets of the heating expansion valve 14a and the cooling expansion valve 14b. presume.

Specifically, the detected value by the discharge refrigerant pressure sensor 62a, the differential pressure between the inlet and outlet of the heating expansion valve 14a and the cooling expansion valve 14b, the water-refrigerant heat exchanger 13, the outdoor heat exchanger 15, and the indoor evaporation It is estimated that the total value of the pressure loss of the evaporator 18 is the refrigerant pressure value corresponding to the detected value of the evaporator refrigerant pressure sensor 62c.

The pressure loss of the indoor evaporator 18 can be estimated by multiplying the flow rate of refrigerant flowing into the fifth three-way joint 12e by the opening area ratio of the cooling expansion valve 14b and the cooling expansion valve 14c. The flow rate of refrigerant flowing into the fifth three-way joint 12e can be estimated from the flow rate of refrigerant discharged from the compressor 11.

In the operation mode in which the bypass flow rate adjustment valve 14d is opened, the total value of the detection value by the discharge refrigerant pressure sensor 62a and the differential pressure between the inlet and outlet of the bypass flow rate adjustment valve 14d and the evaporation pressure adjustment valve 14e is the evaporator refrigerant It is estimated that the refrigerant pressure value corresponds to the value detected by the pressure sensor 62c.

(Third example)
In this embodiment, the chiller refrigerant pressure sensor 62d is reduced using the detected value by the discharge refrigerant pressure sensor 62a and the differential pressure between the inlet and outlet of the heating expansion valve 14a and the cooling expansion valve 14c.

That is, the refrigerant pressure value corresponding to the detected value of the chiller refrigerant pressure sensor 62d is estimated using the detected value of the discharge refrigerant pressure sensor 62a and the differential pressure between the inlets and outlets of the heating expansion valve 14a and the cooling expansion valve 14c. do.

Specifically, the detected value by the discharge refrigerant pressure sensor 62a, the differential pressure between the inlet and outlet of the heating expansion valve 14a and the cooling expansion valve 14c, the water-refrigerant heat exchanger 13, the outdoor heat exchanger 15, and the chiller 20 It is estimated that the total value of pressure loss is the refrigerant pressure value corresponding to the detected value of the chiller refrigerant pressure sensor 62d.

The pressure loss of the chiller 20 can be estimated by multiplying the flow rate of refrigerant flowing into the fifth three-way joint 12e by the opening area ratio of the cooling expansion valve 14c and the cooling expansion valve 14b.

In the case of the operation mode in which the bypass flow rate adjustment valve 14d is opened, the total value of the detection value by the discharge refrigerant pressure sensor 62a and the differential pressure between the inlet and outlet of the bypass flow rate adjustment valve 14d is equal to the detection value of the chiller refrigerant pressure sensor 62d. Estimated to be the corresponding refrigerant pressure value.

(Fourth example)
In this embodiment, the intake refrigerant pressure sensor 62e is reduced using the detected value by the discharge refrigerant pressure sensor 62a and the differential pressure between the inlet and outlet of the heating expansion valve 14a and the cooling expansion valve 14c.

That is, the refrigerant pressure value corresponding to the value detected by the suction refrigerant pressure sensor 62e is estimated using the value detected by the discharge refrigerant pressure sensor 62a and the differential pressure between the inlet and outlet of the heating expansion valve 14a and the cooling expansion valve 14c. do.

Specifically, the detected value by the discharge refrigerant pressure sensor 62a, the differential pressure between the inlet and outlet of the heating expansion valve 14a and the cooling expansion valve 14c, the water-refrigerant heat exchanger 13, the outdoor heat exchanger 15, and the chiller 20 It is estimated that the total value of pressure losses is the refrigerant pressure value corresponding to the detected value of the suction refrigerant pressure sensor 62e.

In the operation mode in which the bypass flow rate adjustment valve 14d is opened, the sum of the detection value by the discharge refrigerant pressure sensor 62a and the differential pressure between the inlet and outlet of the bypass flow rate adjustment valve 14d is equal to the detection value of the suction refrigerant pressure sensor 62e. Estimated to be the corresponding refrigerant pressure value.

(Fifth example)
In this embodiment, the value detected by the outdoor unit refrigerant pressure sensor 62b and the differential pressure between the inlet and outlet of the cooling expansion valve 14b are used to reduce the evaporator refrigerant pressure sensor 62c.

That is, the refrigerant pressure value corresponding to the value detected by the evaporator refrigerant pressure sensor 62c is estimated using the value detected by the outdoor unit refrigerant pressure sensor 62b and the differential pressure between the inlet and outlet of the cooling expansion valve 14b.

Specifically, the sum of the value detected by the outdoor unit refrigerant pressure sensor 62b, the differential pressure between the inlet and outlet of the cooling expansion valve 14b, and the pressure loss of the indoor evaporator 18 is the value detected by the evaporator refrigerant pressure sensor 62c. It is estimated that the refrigerant pressure value corresponds to the value.

In the case of the operation mode in which the heating on-off valve 22b is opened, the sum of the detected value by the outdoor unit refrigerant pressure sensor 62b and the differential pressure between the inlet and outlet of the heating on-off valve 22b and the evaporation pressure adjustment valve 14e is It is estimated that the refrigerant pressure value corresponds to the value detected by the refrigerant pressure sensor 62c.

(6th example)
In this embodiment, the chiller refrigerant pressure sensor 62d is reduced using the detected value by the outdoor unit refrigerant pressure sensor 62b and the differential pressure between the inlet and outlet of the cooling expansion valve 14c.

That is, the refrigerant pressure value corresponding to the value detected by the chiller refrigerant pressure sensor 62d is estimated using the value detected by the outdoor unit refrigerant pressure sensor 62b and the differential pressure between the inlet and outlet of the cooling expansion valve 14c.

Specifically, the sum of the detected value by the outdoor unit refrigerant pressure sensor 62b, the differential pressure between the inlet and outlet of the cooling expansion valve 14c, and the pressure loss of the chiller 20 corresponds to the detected value by the chiller refrigerant pressure sensor 62d. It is estimated that the refrigerant pressure value is

In the case of the operation mode in which the heating on-off valve 22b is opened, the sum of the detected value by the outdoor unit refrigerant pressure sensor 62b and the differential pressure between the inlet and outlet of the heating on-off valve 22b is the detected value of the chiller refrigerant pressure sensor 62d. It is estimated that the refrigerant pressure value corresponds to .

(Seventh Example)
In this embodiment, the suction refrigerant pressure sensor 62e is reduced using the value detected by the outdoor unit refrigerant pressure sensor 62b and the differential pressure between the inlet and outlet of the cooling expansion valve 14c.

That is, the refrigerant pressure value corresponding to the value detected by the suction refrigerant pressure sensor 62e is estimated using the value detected by the outdoor unit refrigerant pressure sensor 62b and the differential pressure between the inlet and outlet of the cooling expansion valve 14c.

Specifically, the sum of the value detected by the outdoor unit refrigerant pressure sensor 62b, the differential pressure between the inlet and outlet of the cooling expansion valve 14c, and the pressure loss of the chiller 20 corresponds to the value detected by the suction refrigerant pressure sensor 62e. It is estimated that the refrigerant pressure value is

In the case of the operation mode in which the heating on-off valve 22b is opened, the sum of the detected value by the outdoor unit refrigerant pressure sensor 62b and the differential pressure between the inlet and outlet of the heating on-off valve 22b is the detected value of the suction refrigerant pressure sensor 62e. It is estimated that the refrigerant pressure value corresponds to .

(Eighth example)
In this embodiment, the chiller refrigerant pressure sensor 62d is reduced using the value detected by the evaporator refrigerant pressure sensor 62c and the differential pressure between the inlet and outlet of the evaporation pressure regulating valve 14e.

That is, the refrigerant pressure value corresponding to the value detected by the chiller refrigerant pressure sensor 62d is estimated using the value detected by the evaporator refrigerant pressure sensor 62c and the differential pressure between the inlet and outlet of the evaporation pressure regulating valve 14e.

Specifically, the sum of the value detected by the evaporator refrigerant pressure sensor 62c and the differential pressure between the inlet and outlet of the evaporator pressure regulating valve 14e is the refrigerant pressure value corresponding to the value detected by the chiller refrigerant pressure sensor 62d. It is estimated that

(9th example)
In this embodiment, the intake refrigerant pressure sensor 62e is reduced using the value detected by the evaporator refrigerant pressure sensor 62c and the differential pressure between the inlet and outlet of the evaporator pressure regulating valve 14e.

That is, the refrigerant pressure value corresponding to the value detected by the suction refrigerant pressure sensor 62e is estimated using the value detected by the evaporator refrigerant pressure sensor 62c and the differential pressure between the inlet and outlet of the evaporation pressure regulating valve 14e.

Specifically, the sum of the value detected by the evaporator refrigerant pressure sensor 62c and the differential pressure between the inlet and outlet of the evaporator pressure regulating valve 14e is the refrigerant pressure value corresponding to the value detected by the suction refrigerant pressure sensor 62e. It is estimated that

(10th example)
In this embodiment, the value detected by the chiller refrigerant pressure sensor 62d is used to eliminate the suction refrigerant pressure sensor 62e.

Specifically, the refrigerant pressure value corresponding to the detection value of the suction refrigerant pressure sensor 62e is estimated to be the same value as that of the chiller refrigerant pressure sensor 62d.

As can be seen from the above explanation, other pressure sensors in the above embodiment are calculated using the detected value by a predetermined pressure sensor, the total value of the differential pressure between the inlet and outlet of an expansion valve, etc., and the pressure loss of a heat exchanger, etc. A refrigerant pressure value corresponding to the refrigerant detection value can be estimated. Therefore, the number of pressure sensors can be reduced compared to the above embodiment.

As a result, the space and wiring required to mount the pressure sensor can be reduced. Furthermore, since the number of input/output ports for pressure sensors in the control device 60 can be reduced, the configuration of the control device 60 can be simplified.

In this embodiment, the control device 60 estimates the differential pressure between the refrigerant inlet and outlet of the electric expansion valve from the operating current of the electric expansion valve, and uses the electric expansion valve based on the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. At least one of the opening degree of the type expansion valve and the rotation speed of the compressor 11 is controlled.

According to this, the differential pressure between the refrigerant inlet and outlet of the electric expansion valve can be obtained from the operating current of the electric expansion valve, so the number of pressure sensors can be reduced in a refrigeration cycle device that is controlled based on the pressure of the refrigerant.

In this embodiment, the pressure of the refrigerant in the evaporator is estimated based on the pressure detected by the pressure sensor on the upstream side of the electric expansion valve and the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. The rotational speed of the compressor 11 and the opening degree of the electric expansion valve are controlled based on the pressure.

According to this, the pressure of the refrigerant in the evaporator can be obtained without using a pressure sensor that detects the pressure of the refrigerant in the evaporator, so the number of pressure sensors can be reduced and the number of revolutions of the compressor 11 and the electric expansion valve can be adjusted. Opening degree can be controlled appropriately.

In this embodiment, the control device 60 estimates the refrigerant pressure in the evaporator based on the pressure detected by the pressure sensor on the upstream side of the electric expansion valve and the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. , the opening degree of the evaporation pressure regulating valve 14e is controlled based on the pressure of the refrigerant in the evaporator.

Thereby, the opening degree of the evaporation pressure regulating valve 14e can be controlled without using a pressure sensor that detects the pressure of the refrigerant in the evaporator, so the number of pressure sensors that detect the pressure of the refrigerant in the evaporator can be reduced.

In this embodiment, the control device 60 estimates the refrigerant pressure in the evaporator based on the pressure detected by the pressure sensor on the upstream side of the electric expansion valve and the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. , an electric expansion valve so that the degree of superheating SH of the refrigerant sucked into the compressor 11 approaches the reference degree of superheating KSH based on the pressure of the refrigerant in the evaporator and the temperature of the refrigerant detected by the evaporator refrigerant temperature sensor. Controls the opening degree.

As a result, the degree of superheating SH of the refrigerant sucked into the compressor 11 can be brought close to the reference degree of superheating KSH without using a pressure sensor that detects the pressure of the refrigerant in the evaporator, so the pressure of the refrigerant in the evaporator can be detected. It is possible to reduce the number of pressure sensors used.

In this embodiment, the control device 60 estimates the differential pressure between the refrigerant inlet and outlet of the bypass expansion valve 14d from the operating current of the bypass expansion valve 14d, and bypasses the bypass based on the differential pressure between the refrigerant inlet and outlet of the bypass expansion valve 14d. Controls the opening degree of the expansion valve 14d.

According to this, the differential pressure between the refrigerant inlet and outlet of the bypass expansion valve 14d can be obtained from the operating current of the bypass expansion valve 14d, so in a refrigeration cycle device where the opening degree of the bypass expansion valve 14d is controlled based on the pressure of the refrigerant. The number of pressure sensors can be reduced.

(Third embodiment)
As shown in FIG. 8, the refrigeration cycle 10 of this embodiment constitutes a gas injection cycle when switched to the heating mode refrigerant circuit. Therefore, the compressor 11 of this embodiment is a two-stage boost type electric compressor. The compressor 11, which is a two-stage boost type electric compressor, has two compression mechanisms, a low-stage compression mechanism and a high-stage compression mechanism, and both compression mechanisms inside a housing that forms its outer shell. It houses an electric motor that drives the rotation.

The housing of the compressor 11 is provided with a suction port 11a, an intermediate pressure port 11b, and a discharge port 11c. The suction port 11a is a suction port for sucking low-pressure refrigerant into the low-stage compression mechanism from the outside of the housing. The discharge port 11c is a discharge port that discharges the high-pressure refrigerant discharged from the high-stage compression mechanism to the outside of the housing.

The intermediate pressure port 11b is an intermediate pressure suction port that allows intermediate pressure refrigerant to flow into the housing from the outside of the housing to join the refrigerant in the compression process from low pressure to high pressure. That is, the intermediate pressure port 11b is connected to the discharge port side of the low stage compression mechanism and the suction port side of the high stage compression mechanism inside the housing.

Although the compressor 11 of this embodiment accommodates two compression mechanisms in one housing, the type of the two-stage boost compressor is not limited to this. The compressor 11 of this embodiment has one fixed capacity type refrigerant inside the housing, if it is possible to let the intermediate pressure refrigerant flow in from the intermediate pressure port 11b and join the refrigerant in the compression process from low pressure to high pressure. The electric compressor may include a compression mechanism and an electric motor that rotationally drives the compression mechanism.

The compressor 11 of this embodiment has two compressors connected in series, the suction port of the low-stage compressor disposed on the low-stage side being the suction port 11a, and the high-stage compressor disposed on the high-stage side serving as a suction port 11a. The discharge port of the side compressor is set as a discharge port 11c, and an intermediate pressure port 11b is provided at the connection part connecting the discharge port of the low stage compressor and the suction port of the high stage compressor. The electric compressor may be an electric compressor in which both the high-stage compressor and the high-stage compressor constitute one two-stage step-up compressor.

The discharge port 11c of the compressor 11 is connected to the inlet side of the refrigerant passage of the water-refrigerant heat exchanger 13. The outlet of the refrigerant passage of the water-refrigerant heat exchanger 13 is connected to the refrigerant inlet side of an intermediate pressure expansion valve 14f that reduces the pressure of the refrigerant flowing out of the water-refrigerant heat exchanger 13 to an intermediate pressure. The basic configuration of the intermediate pressure expansion valve 14f is the same as that of the bypass flow rate adjustment valve 14d.

A refrigerant inlet of a gas-liquid separator 24, which is a gas-liquid separator that separates gas and liquid of the refrigerant flowing out from the intermediate-pressure expansion valve 14f, is connected to the refrigerant outlet side of the intermediate-pressure expansion valve 14f. In this embodiment, the gas-liquid separator 24 uses a centrifugal separation method (cyclone separator method) in which gas and liquid of the refrigerant are separated by the action of centrifugal force generated by swirling the refrigerant that has flowed into the internal space of the cylindrical main body. We are using the following.

The gas-phase refrigerant outlet of the gas-liquid separator 24 is connected to the intermediate pressure port 11b of the compressor 11 via the injection on-off valve 22c. The injection on-off valve 22c opens and closes the intermediate pressure refrigerant passage 21e that connects the gas phase refrigerant outlet of the gas-liquid separator 24 and the intermediate pressure port 11b of the compressor 11. The injection opening/closing valve 22c is a solenoid valve whose opening/closing operation is controlled by a control voltage output from the control device 60. The injection on-off valve 22c can switch the refrigerant circuit by opening and closing the intermediate pressure refrigerant passage 21e. Therefore, the injection on-off valve 22c is a refrigerant circuit switching section.

The liquid phase refrigerant outlet of the gas-liquid separator 24 is connected to the inlet of the second three-way joint 12b. The other configurations of the vehicle air conditioner 1 and the refrigeration cycle 10 are the same as those of the vehicle air conditioner 1 and the refrigeration cycle 10 described in the first embodiment.

Next, the operation of the above configuration will be explained. In the vehicle air conditioner 1 of this embodiment, various driving modes are switched in order to air condition the vehicle interior and adjust the temperature of the battery 70, similarly to the first embodiment. Below, the heating mode will be explained among the various operating modes executed by the vehicle air conditioner 1 of this embodiment, and the explanation of the other operating modes will be omitted.

In the heating mode, the control device 60 causes the intermediate pressure expansion valve 14f to be in the throttled state, the heating expansion valve 14a to be in the throttled state, the cooling expansion valve 14b to be in the fully closed state, the dehumidification on-off valve 22a to be closed, and the injection opening/closing valve to be closed. Open valve 22c.

As a result, in the refrigeration cycle 10 in the heating mode, the compressor 11, the water-refrigerant heat exchanger 13, the intermediate pressure expansion valve 14f, the gas-liquid separator 24, the heating expansion valve 14a, the outdoor heat exchanger 15, and the compressor 11 in this order. A gas injection cycle is configured in which the refrigerant circulates and intermediate-pressure gas-phase refrigerant flows from the gas-phase refrigerant outlet of the gas-liquid separator 24 to the intermediate-pressure port 11b of the compressor 11.

With this cycle configuration, the control device 60 controls the operation of various control target devices similarly to the heating mode of the first embodiment.

Therefore, in the refrigeration cycle 10 in the heating mode, a gas injection cycle is configured in which the water-refrigerant heat exchanger 13 functions as a radiator and the outdoor heat exchanger 15 functions as an evaporator. Then, the heat absorbed from the outside air when the refrigerant evaporates in the outdoor heat exchanger 15 is radiated to the cooling water in the water-refrigerant heat exchanger 13. Thereby, the cooling water can be heated.

At this time, in the gas injection cycle, the intermediate pressure refrigerant whose pressure has been reduced by the intermediate pressure expansion valve 14f is merged with the intermediate pressure refrigerant in the pressure increasing process in the compressor 11, and the pressure of the refrigerant is increased in multiple stages. Efficiency can be improved. Thereby, in the gas injection cycle, even in the heating mode in which the difference between high and low pressures in the cycle is larger than in the cooling mode, a decrease in COP can be suppressed.

As a result, in the heating mode, the interior of the vehicle can be heated by blowing air heated by the heater core 32 into the vehicle interior.

In the heating mode, the intermediate pressure air flowing into the intermediate pressure port 11b of the compressor 11 is controlled using the refrigerant pressure value detected by the discharge refrigerant pressure sensor 62a and the pressure difference between the inlet and outlet of the intermediate pressure expansion valve 14f. Estimate the pressure of the phase refrigerant.

Then, based on the estimated pressure value of the intermediate-pressure gas phase refrigerant, the opening degrees of the intermediate-pressure expansion valve 14f, the cooling expansion valve 14b, and the heating expansion valve 14a are controlled.

Therefore, without providing a pressure sensor for detecting the pressure of the intermediate-pressure gas phase refrigerant flowing into the intermediate-pressure port 11b of the compressor 11, the intermediate-pressure expansion valve 14f, the cooling expansion valve 14b, and the heating expansion valve 14a. Opening degree can be controlled.

In this embodiment, the control device 60 estimates the differential pressure between the refrigerant inlet and outlet of the intermediate pressure expansion valve 14f from the operating current of the intermediate pressure expansion valve 14f, and estimates the differential pressure between the refrigerant inlet and outlet of the intermediate pressure expansion valve 14f, and estimates the pressure difference between the refrigerant inlet and outlet of the intermediate pressure expansion valve 14f, and estimates the pressure difference between the refrigerant inlet and outlet of the intermediate pressure expansion valve 14f, and estimates the pressure difference between the refrigerant inlet and outlet of the intermediate pressure expansion valve 14f, and estimates the pressure difference between the refrigerant inlet and outlet of the intermediate pressure expansion valve 14f, and estimates the pressure difference between the refrigerant inlet and outlet of the intermediate pressure expansion valve 14f, and the Estimate the pressure based on the pressure detected by the discharge refrigerant pressure sensor 62a downstream of the compressor 11 and upstream of the intermediate pressure expansion valve 14f and the differential pressure between the refrigerant inlet and outlet of the intermediate pressure expansion valve 14f, Based on the pressure of the refrigerant sucked into the high-stage compression mechanism of the compressor 11, the opening degrees of the cooling expansion valve 14b, the cooling expansion valve 14c, and the intermediate pressure expansion valve 14f are controlled.

As a result, the opening degrees of the cooling expansion valve 14b, the cooling expansion valve 14c, and the intermediate pressure expansion valve 14f are controlled without using a pressure sensor that detects the pressure of the refrigerant sucked into the high-stage compression mechanism of the compressor 11. Therefore, the number of pressure sensors that detect the pressure of the refrigerant sucked into the high-stage compression mechanism of the compressor 11 can be reduced.

(Fourth embodiment)
In the refrigeration cycle of the second embodiment, when the refrigerant circuit is switched to the heating mode, intermediate-pressure gas-phase refrigerant flows from the gas-phase refrigerant outlet 24a of the gas-liquid separator 24 to the intermediate-pressure port 11b of the compressor 11. Configure the gas injection cycle to On the other hand, as shown in FIG. 9, in the refrigeration cycle 10 of this embodiment, when switching to the heating mode refrigerant circuit, the intermediate pressure gas phase refrigerant that has been heat exchanged in the internal heat exchanger 25 is transferred to the compressor. A gas injection cycle is configured in which the gas flows into the intermediate pressure port 11b of No. 11.

The outlet of the refrigerant passage of the water-refrigerant heat exchanger 13 is connected to the inlet side of the eighth three-way joint 12h. The refrigerant inlet side of the intermediate pressure expansion valve 14f is connected to one outlet side of the eighth three-way joint 12h. The high-pressure refrigerant inlet of the internal heat exchanger 25 is connected to the other outlet side of the eighth three-way joint 12h. The high-pressure refrigerant outlet of the internal heat exchanger 25 is connected to the inlet of the second three-way joint 12b.

The intermediate pressure refrigerant inlet of the internal heat exchanger 25 is connected to the refrigerant outlet side of the intermediate pressure expansion valve 14f. The intermediate pressure refrigerant outlet of the internal heat exchanger 25 is connected to the intermediate pressure port 11b of the compressor 11 via the injection on-off valve 22c.

The other configurations of the vehicle air conditioner 1 and the refrigeration cycle 10 are the same as those of the vehicle air conditioner 1 and the refrigeration cycle 10 described in the third embodiment.

Next, the operation of the above configuration will be explained. In the vehicle air conditioner 1 of this embodiment, various driving modes are switched in order to air condition the vehicle interior and adjust the temperature of the battery 70, similarly to the first embodiment. Below, the heating mode will be explained among the various operating modes executed by the vehicle air conditioner 1 of this embodiment, and the explanation of the other operating modes will be omitted.

In the heating mode, the control device 60 causes the intermediate pressure expansion valve 14f to be in the throttled state, the heating expansion valve 14a to be in the throttled state, the cooling expansion valve 14b to be in the fully closed state, the dehumidification on-off valve 22a to be closed, and the injection opening/closing valve to be closed. Open valve 22c.

As a result, in the refrigeration cycle 10 in the heating mode, the refrigerant circulates in the order of the compressor 11, the water-refrigerant heat exchanger 13, the internal heat exchanger 25, the heating expansion valve 14a, the outdoor heat exchanger 15, and the compressor 11. The refrigerant heat-exchanged in the water-refrigerant heat exchanger 13 is depressurized to an intermediate pressure by the intermediate pressure expansion valve 14f, and then evaporated in the internal heat exchanger 25 to become an intermediate pressure gas phase refrigerant. A gas injection cycle is configured to flow into port 11b.

With this cycle configuration, the control device 60 controls the operation of various control target devices similarly to the heating mode of the first embodiment.

Therefore, in the refrigeration cycle 10 in the heating mode, a gas injection cycle is configured in which the water-refrigerant heat exchanger 13 functions as a radiator and the outdoor heat exchanger 15 functions as an evaporator. Then, the heat absorbed from the outside air when the refrigerant evaporates in the outdoor heat exchanger 15 is radiated to the cooling water in the water-refrigerant heat exchanger 13. Thereby, the cooling water can be heated.

At this time, in the gas injection cycle, the intermediate pressure refrigerant that has flowed through the intermediate pressure expansion valve 14f and the internal heat exchanger 25 is combined with the intermediate pressure refrigerant in the pressure increasing process in the compressor 11, and the pressure of the refrigerant is increased in multiple stages. , the compression efficiency of the compressor can be improved. Thereby, in the gas injection cycle, even in the heating mode in which the difference between high and low pressures in the cycle is larger than in the cooling mode, a decrease in COP can be suppressed.

As a result, in the heating mode, the interior of the vehicle can be heated by blowing air heated by the heater core 32 into the vehicle interior.

In the heating mode, the intermediate pressure air flowing into the intermediate pressure port 11b of the compressor 11 is controlled using the refrigerant pressure value detected by the discharge refrigerant pressure sensor 62a and the pressure difference between the inlet and outlet of the intermediate pressure expansion valve 14f. Estimate the pressure of the phase refrigerant.

Then, based on the estimated pressure value of the intermediate-pressure gas phase refrigerant, the opening degrees of the intermediate-pressure expansion valve 14f, the cooling expansion valve 14b, and the heating expansion valve 14a are controlled.

Therefore, without providing a sensor for detecting the pressure of the intermediate-pressure gas phase refrigerant flowing into the intermediate-pressure port 11b of the compressor 11, the intermediate-pressure expansion valve 14f, the cooling expansion valve 14b, and the heating expansion valve 14a can be opened. You can control the degree.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and can be modified in various ways as described below without departing from the spirit of the present invention.

(1) In the above-described embodiment, an example was explained in which the refrigeration cycle device was applied to an air conditioner, but the application target of the refrigeration cycle device is not limited to an air conditioner. For example, the present invention may be applied to a water heater that heats household water or the like as an object to be heated. Furthermore, the object to be heated is not limited to fluid. For example, it may be a heat-generating device in which a heat medium passage through which a high-temperature heat medium flows is formed for warming up or the like.

(2) The configuration of the refrigeration cycle device is not limited to the configuration disclosed in the above embodiment.

In the above-described embodiment, an example in which the evaporation pressure adjustment valve 14e is employed has been described, but a check valve may be employed in place of the evaporation pressure adjustment valve 14e.

The control sensor group connected to the input side of the control device 60 is not limited to the detection unit disclosed in the above embodiment. Various detection units may be added as necessary.

In the above-described embodiment, an example was described in which R1234yf was employed as the refrigerant of the refrigeration cycle 10, but the present invention is not limited thereto. For example, R134a, R600a, R410A, R404A, R32, R407C, etc. may be adopted. Alternatively, a mixed refrigerant made by mixing a plurality of these refrigerants may be employed. Furthermore, a supercritical refrigeration cycle may be constructed in which carbon dioxide is used as the refrigerant, and the refrigerant pressure on the high-pressure side is equal to or higher than the critical pressure of the refrigerant.

Although an example has been described in which an aqueous ethylene glycol solution is used as the low-temperature side heat medium and the high-temperature side heat medium in the above embodiment, the present invention is not limited thereto. As the high-temperature side heat medium and the low-temperature side heat medium, for example, dimethylpolysiloxane, a solution containing nanofluid, etc., an antifreeze solution, an aqueous liquid refrigerant containing alcohol, etc., a liquid medium containing oil, etc. may be employed.

(3) The control mode of the refrigeration cycle device is not limited to the control mode disclosed in the above embodiment.

In the above-mentioned embodiment, the vehicle air conditioner 1 that can execute various operation modes has been described, but the refrigeration cycle apparatus according to the present invention does not need to be able to execute all of the above-mentioned operation modes.

If the refrigeration cycle device can execute at least one of the above-mentioned operation modes, it can obtain the same effects as the above-described embodiments.

Furthermore, other operation modes may be possible. For example, it may be possible to execute an equipment cooling mode in which only the battery 70 is cooled without performing air conditioning in the vehicle interior. Specifically, when executing the device cooling mode, the control device 60 switches the refrigerant circuit of the refrigeration cycle 10 in the same manner as in the cooling cooling mode, and brings the cooling expansion valve 14b into a fully closed state. Further, the control device 60 may stop the indoor blower 52.

(4) An indoor condenser may be provided in place of the water-refrigerant heat exchanger 13 and the high-temperature side heat medium circuit 30 in the above-described embodiment. The indoor condenser is a heating heat exchanger that heats the air by exchanging heat between the high-pressure refrigerant discharged from the compressor 11 and the air that has passed through the indoor evaporator 18.

(5) In the above embodiment, the motor torque is estimated by detecting the motor current value, and the differential pressure of the valve is estimated from the estimated torque. However, by attaching a torque sensor to the motor shaft, Effects equivalent to those of the above embodiment can be obtained.

As a method for detecting motor torque, the torque can also be estimated from the twist angle of the shaft material by detecting the rotation angle difference between the load side and the motor side of the shaft. This is because the twist angle is proportional to the torque depending on the material, thickness, and length of the shaft.

By providing a sensor capable of measuring force (for example, a strain gauge, a pressure sensor, a piezoelectric element, etc.) on the rod that connects the valve body, the force that the valve body receives can be directly detected. This makes it possible to obtain effects similar to those of the above-described embodiment. This method can be seen to be the same as the principle of a pressure sensor, so it can be said to be equivalent to installing a pressure sensor.

(6) In the above-described embodiment, if the motor control method is a method of controlling the current to the coil by switching a constant voltage power supply (so-called PWM method), the current can be estimated from the energization on/off ratio. As a method of detecting motor current consumption, a current sensor may directly detect the coil current.

(7) In the third to fourth embodiments described above, a condensed refrigerant pressure sensor is provided to detect the condensed refrigerant pressure, which is the pressure of the refrigerant flowing out from the water-refrigerant heat exchanger 13, and the condensed refrigerant pressure sensor detects the pressure in the heating mode. The pressure of the intermediate-pressure gas phase refrigerant flowing into the intermediate-pressure port 11b of the compressor 11 may be estimated using the condensed refrigerant pressure value and the pressure difference between the inlet and outlet of the intermediate-pressure expansion valve 14f. .

(8) In the first embodiment, the control device 60 estimates the differential pressure between the refrigerant inlet and outlet of the electric expansion valve from the operating current of the electric expansion valve located between the two pressure sensors, and The reliability of the detected values of the two pressure sensors is determined based on the differential pressure between the refrigerant inlet and outlet of the valve.

On the other hand, the control device 60 calculates the pressure difference between the refrigerant inlet and outlet of the electric expansion valve from the operating current of the electric expansion valve located between the two pressure sensors (i.e., the upstream pressure sensor and the downstream pressure sensor). may be estimated, and it may be determined whether or not an abnormality has occurred in the electric expansion valve based on the differential pressure between the refrigerant inlet and outlet of the electric expansion valve and the detected values of the two pressure sensors.

In other words, when using a pressure sensor with high durability and reliability, if there is a difference between the differential pressure estimated from the operating current of the electric expansion valve and the detected value of two highly reliable pressure sensors, It is possible to determine that an abnormality has occurred in the electric expansion valve.

For example, it can be determined that a failure mode has occurred in which the torque of the electric expansion valve becomes abnormally low or low. The main failure modes of such electric expansion valves are when the gears in the power transmission section of the electric expansion valve become out of engagement, or when the gears in the power transmission section have become entangled with foreign matter and abnormal torque is required. occurs in

The characteristics of the refrigeration cycle device disclosed in this specification are shown below.

(Item 1)
a compressor (11) that sucks in refrigerant, compresses it, and discharges it;
a radiator (13) that radiates heat from the refrigerant discharged from the compressor;
an electric expansion valve (14a, 14b, 14c) that decompresses and expands the refrigerant heat radiated by the radiator according to an operating current;
an evaporator (15, 18, 20) that evaporates the refrigerant expanded under reduced pressure by the electric expansion valve;
an upstream pressure sensor (62a, 62b) that detects the pressure of the refrigerant downstream of the compressor and upstream of the electric expansion valve;
a downstream pressure sensor (62c, 62d, 62e) that detects the pressure of the refrigerant downstream of the electric expansion valve and upstream of the compressor;
The differential pressure between the refrigerant inlet and outlet of the electric expansion valve is estimated from the operating current of the electric expansion valve, and the upstream pressure sensor and the downstream pressure sensor are estimated based on the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. A refrigeration cycle device including a determination unit (60) that determines the reliability of a detected value of a side pressure sensor.

(Item 2)
The refrigeration cycle device according to item 1, wherein the determination unit estimates that the greater the operating current of the electric expansion valve, the greater the differential pressure between the refrigerant inlet and outlet of the electric expansion valve.

(Item 3)
An item comprising a compressor control unit (60a) that stops operation of the compressor when the determination unit determines that the detected value of at least one of the upstream pressure sensor and the downstream pressure sensor is unreliable. The refrigeration cycle device according to 1 or 2.

(Item 4)
The determination unit estimates the differential pressure between the refrigerant inlet and outlet of the electric expansion valve from the operating current of the electric expansion valve, and estimates the differential pressure between the refrigerant inlet and outlet of the electric expansion valve and the upstream pressure sensor. The refrigeration cycle device according to any one of items 1 to 3, wherein it is determined whether or not an abnormality has occurred in the electric expansion valve based on the detected value of the downstream pressure sensor.

(Item 5)
a compressor (11) that sucks in refrigerant, compresses it, and discharges it;
a radiator (13) that radiates heat from the refrigerant discharged from the compressor;
an electric expansion valve (14a, 14b, 14c) that decompresses and expands the refrigerant heat radiated by the radiator according to an operating current;
an evaporator (15, 18, 20) that evaporates the refrigerant expanded under reduced pressure by the electric expansion valve;
The differential pressure between the refrigerant inlet and outlet of the electric expansion valve is estimated from the operating current of the electric expansion valve, and the opening degree of the electric expansion valve is determined based on the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. and a control unit (60) that controls at least one of the rotation speeds of the compressor.

(Item 6)
an upstream pressure sensor (62a, 62b) that detects the pressure of the refrigerant downstream of the compressor and upstream of the electric expansion valve;
The control unit estimates the pressure of the refrigerant in the evaporator based on the pressure detected by the upstream pressure sensor and the pressure difference between the refrigerant inlet and outlet of the electric expansion valve, and estimates the pressure of the refrigerant in the evaporator. The refrigeration cycle device according to item 5, wherein the rotation speed of the compressor and the opening degree of the electric expansion valve are controlled based on the pressure of the compressor.

(Item 7)
an evaporation pressure regulating valve (14e) disposed on the downstream side of the refrigerant flow of the evaporator to maintain the refrigerant evaporation temperature in the evaporator at a predetermined temperature or higher;
The control unit estimates the pressure of the refrigerant in the evaporator based on the pressure detected by the upstream pressure sensor and the differential pressure between the refrigerant inlet and outlet of the electric expansion valve, and controls the refrigerant in the evaporator. The refrigeration cycle device according to item 6, wherein the opening degree of the evaporation pressure regulating valve is controlled based on the pressure of the evaporation pressure regulating valve.

(Item 8)
A refrigerant temperature sensor (62i, 62j) that detects the temperature of the refrigerant flowing out from the evaporator,
The control unit estimates the pressure of the refrigerant in the evaporator based on the pressure detected by the upstream pressure sensor and the differential pressure between the refrigerant inlet and outlet of the electric expansion valve, and controls the refrigerant in the evaporator. and the temperature of the refrigerant detected by the refrigerant temperature sensor, the electric expansion is performed so that the degree of superheat (SH) of the refrigerant sucked into the compressor approaches the reference degree of superheat (KSH). The refrigeration cycle device according to item 6 or 7, which controls the opening degree of the valve.

(Item 9)
an intermediate pressure expansion valve (14f) that depressurizes and expands the refrigerant heat radiated by the radiator to an intermediate pressure according to an operating current;
The compressor includes a low-stage compression mechanism that compresses the refrigerant evaporated by the evaporator, and a low-stage compression mechanism that compresses the refrigerant compressed by the low-stage compression mechanism and the refrigerant expanded under reduced pressure by the intermediate pressure expansion valve. A two-stage boost compressor having a high-stage side compression mechanism for compressing,
The upstream pressure sensor detects the pressure of the refrigerant downstream of the compressor and upstream of the intermediate pressure expansion valve,
The control unit estimates the pressure difference between the refrigerant inlet and outlet of the intermediate pressure expansion valve from the operating current of the intermediate pressure expansion valve, and adjusts the pressure of the refrigerant sucked into the high stage compression mechanism from the upstream side. The intermediate pressure expansion valve is estimated based on the pressure detected by the pressure sensor and the differential pressure between the refrigerant inlet and outlet of the intermediate pressure expansion valve, and The refrigeration cycle device according to item 6 or 7, which controls the opening degree of the electric expansion valve.

(Item 10)
a bypass passage (21c) that returns the refrigerant discharged from the compressor to the suction side of the compressor;
An electric bypass expansion valve (14d) that adjusts the opening degree of the bypass passage according to the operating current,
The control unit estimates a pressure difference between the refrigerant inlet and outlet of the bypass expansion valve from an operating current of the bypass expansion valve, and controls the opening of the bypass expansion valve based on the pressure difference between the refrigerant inlet and outlet of the bypass expansion valve. The refrigeration cycle device according to any one of items 5 to 9, which controls temperature.

11 Compressor 13 Water refrigerant heat exchanger (radiator)
14a Heating expansion valve (electric expansion valve)
14b Cooling expansion valve (electric expansion valve)
14c Cooling expansion valve (electric expansion valve)
15 Outdoor heat exchanger (evaporator)
18 Indoor evaporator (evaporator)
20 Chiller (evaporator)
60 Control device (judgment unit, control unit)
62a Discharge refrigerant pressure sensor (upstream pressure sensor)
62b Outdoor unit refrigerant pressure sensor (upstream pressure sensor)
62c Evaporator refrigerant pressure sensor (downstream pressure sensor)
62d Chiller refrigerant pressure sensor (downstream pressure sensor)
62e Suction refrigerant pressure sensor (downstream pressure sensor)

Claims (10)

a compressor (11) that sucks in refrigerant, compresses it, and discharges it;
a radiator (13) that radiates heat from the refrigerant discharged from the compressor;
an electric expansion valve (14a, 14b, 14c) that decompresses and expands the refrigerant heat radiated by the radiator according to an operating current;
an evaporator (15, 18, 20) that evaporates the refrigerant expanded under reduced pressure by the electric expansion valve;
an upstream pressure sensor (62a, 62b) that detects the pressure of the refrigerant downstream of the compressor and upstream of the electric expansion valve;
a downstream pressure sensor (62c, 62d, 62e) that detects the pressure of the refrigerant downstream of the electric expansion valve and upstream of the compressor;
The differential pressure between the refrigerant inlet and outlet of the electric expansion valve is estimated from the operating current of the electric expansion valve, and the upstream pressure sensor and the downstream pressure sensor are estimated based on the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. A refrigeration cycle device including a determination unit (60) that determines the reliability of a detected value of a side pressure sensor. The refrigeration cycle device according to claim 1, wherein the determination unit estimates that the greater the operating current of the electric expansion valve, the greater the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. A compressor control unit (60a) that stops operation of the compressor when the determination unit determines that the detected value of at least one of the upstream pressure sensor and the downstream pressure sensor is unreliable. Item 2. Refrigeration cycle device according to item 1 or 2. The determination unit estimates the differential pressure between the refrigerant inlet and outlet of the electric expansion valve from the operating current of the electric expansion valve, and estimates the differential pressure between the refrigerant inlet and outlet of the electric expansion valve and the upstream pressure sensor. The refrigeration cycle device according to claim 1 or 2, wherein it is determined whether or not an abnormality has occurred in the electric expansion valve based on the detected value of the downstream pressure sensor. a compressor (11) that sucks in refrigerant, compresses it, and discharges it;
a radiator (13) that radiates heat from the refrigerant discharged from the compressor;
an electric expansion valve (14a, 14b, 14c) that decompresses and expands the refrigerant heat radiated by the radiator according to an operating current;
an evaporator (15, 18, 20) that evaporates the refrigerant expanded under reduced pressure by the electric expansion valve;
The differential pressure between the refrigerant inlet and outlet of the electric expansion valve is estimated from the operating current of the electric expansion valve, and the opening degree of the electric expansion valve is determined based on the differential pressure between the refrigerant inlet and outlet of the electric expansion valve. and a control unit (60) that controls at least one of the rotation speeds of the compressor. an upstream pressure sensor (62a, 62b) that detects the pressure of the refrigerant downstream of the compressor and upstream of the electric expansion valve;
The control unit estimates the pressure of the refrigerant in the evaporator based on the pressure detected by the upstream pressure sensor and the differential pressure between the refrigerant inlet and outlet of the electric expansion valve, and controls the refrigerant in the evaporator. The refrigeration cycle device according to claim 5, wherein the rotation speed of the compressor and the opening degree of the electric expansion valve are controlled based on the pressure of the compressor. an evaporation pressure regulating valve (14e) disposed on the downstream side of the refrigerant flow of the evaporator to maintain the refrigerant evaporation temperature in the evaporator at a predetermined temperature or higher;
The control unit estimates the pressure of the refrigerant in the evaporator based on the pressure detected by the upstream pressure sensor and the differential pressure between the refrigerant inlet and outlet of the electric expansion valve, and controls the refrigerant in the evaporator. The refrigeration cycle device according to claim 6, wherein the opening degree of the evaporation pressure regulating valve is controlled based on the pressure of the evaporation pressure regulating valve. A refrigerant temperature sensor (62i, 62j) that detects the temperature of the refrigerant flowing out from the evaporator,
The control unit estimates the pressure of the refrigerant in the evaporator based on the pressure detected by the upstream pressure sensor and the differential pressure between the refrigerant inlet and outlet of the electric expansion valve, and controls the refrigerant in the evaporator. and the temperature of the refrigerant detected by the refrigerant temperature sensor, the electric expansion is performed so that the degree of superheat (SH) of the refrigerant sucked into the compressor approaches the reference degree of superheat (KSH). The refrigeration cycle device according to claim 6, wherein the opening degree of the valve is controlled. an intermediate pressure expansion valve (14f) that depressurizes and expands the refrigerant heat radiated by the radiator to an intermediate pressure according to an operating current;
The compressor includes a low-stage compression mechanism that compresses the refrigerant evaporated by the evaporator, and a low-stage compression mechanism that compresses the refrigerant compressed by the low-stage compression mechanism and the refrigerant expanded under reduced pressure by the intermediate pressure expansion valve. A two-stage boost compressor having a high-stage side compression mechanism for compressing,
The upstream pressure sensor detects the pressure of the refrigerant downstream of the compressor and upstream of the intermediate pressure expansion valve,
The control unit estimates the pressure difference between the refrigerant inlet and outlet of the intermediate pressure expansion valve from the operating current of the intermediate pressure expansion valve, and adjusts the pressure of the refrigerant sucked into the high stage compression mechanism from the upstream side. The intermediate pressure expansion valve is estimated based on the pressure detected by the pressure sensor and the differential pressure between the refrigerant inlet and outlet of the intermediate pressure expansion valve, and The refrigeration cycle device according to claim 6, wherein the opening degree of the electric expansion valve is controlled. a bypass passage (21c) that returns the refrigerant discharged from the compressor to the suction side of the compressor;
An electric bypass expansion valve (14d) that adjusts the opening degree of the bypass passage according to the operating current,
The control unit estimates a pressure difference between the refrigerant inlet and outlet of the bypass expansion valve from an operating current of the bypass expansion valve, and controls the opening of the bypass expansion valve based on the pressure difference between the refrigerant inlet and outlet of the bypass expansion valve. The refrigeration cycle device according to any one of claims 5 to 9, which controls the temperature.

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