JP5321647B2 - Refrigeration cycle equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating cycle device in which a radiator can have sufficient external fluid heating capability even when heat absorbing capability of an evaporator is restricted. <P>SOLUTION: A cycle refrigerant circulation flow rate is determined by a restriction of heat absorbing capability of an evaporator 27, and when heating capability of a condenser 22 is insufficient even when heat absorbing capability of an outdoor heat exchanger 24 is maximized even by fully opening a variable throttle valve 26 for cooling, enthalpy of a refrigerant flowing in the condenser 22 is increased by decompressing a refrigerant evaporated by the evaporator 27 temporarily by a suction refrigerant throttle valve 50 and compressing the refrigerant, decompressed by the suction refrigerant throttle valve 50, by a compressor 21 in an isentropic manner. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to a vapor compression refrigeration cycle apparatus including a compressor, a radiator, a decompression unit, and an evaporator.

  Conventionally, there is a refrigeration cycle apparatus used for an air conditioner that cannot use waste heat of an engine such as an electric vehicle. Such a refrigeration cycle apparatus includes a compressor that sucks and compresses a refrigerant, discharges the refrigerant, a condenser that dissipates heat of the refrigerant discharged from the compressor to an external fluid, an expansion valve that decompresses and expands the refrigerant that has flowed out of the condenser, And the evaporator which evaporates the refrigerant | coolant decompressed with the expansion valve and absorbs heat from an external fluid is provided. Then, an evaporator and a condenser are provided in the air conditioning duct, and the evaporator is used as a heat exchanger for air conditioning wind cooling and dehumidification, and the vehicle interior is dehumidified and heated using the condenser as a heat exchanger for heating air conditioning air. (For example, refer to Patent Document 1).

JP 2000-16072 A

  However, in the prior art refrigeration cycle apparatus, a lower limit may be imposed on the refrigerant pressure in the evaporator, for example, in order to prevent frosting of the evaporator for absorbing heat from the air. If there is a restriction on the refrigerant pressure drop of the evaporator, the heat absorption capacity of the evaporator is restricted (the evaporator load is low and the heat absorption capacity cannot be demonstrated), and the air heating capacity (external fluid heating capacity) of the condenser as a radiator ) May be insufficient.

  The present invention has been made in view of the above points, and provides a refrigeration cycle apparatus capable of obtaining a sufficient external fluid heating capability in a radiator even when there is a restriction on the heat absorption capability of the evaporator. With the goal.

In order to achieve the above object, in the invention described in claim 1,
A compressor (21) for sucking and compressing and discharging the refrigerant;
A radiator (22) for radiating the heat of the refrigerant discharged from the compressor (21) to heat the external fluid;
First decompression means (23) for decompressing and expanding the refrigerant flowing out of the radiator (22);
An evaporator (27) for evaporating the refrigerant decompressed by the first decompression means (23) and absorbing heat from the external fluid;
A second decompression means (50) capable of changing a decompression amount for decompressing the refrigerant evaporated by the evaporator (27) and sucked by the compressor (21),
One of the discharge capacity of the compressor (21) and the pressure reduction amount of the second pressure reducing means (50) so that the heating capacity of the radiator (22) or the value (TAV) of the related physical quantity matches the heating target value (TAO). And adjusting the other of the discharge capacity and the pressure reduction amount so that the endothermic capacity of the evaporator (27) or the value (TE) of the related physical quantity matches the endothermic target value (TEO).

  According to this, when the endothermic capacity of the evaporator (27) or the value of the related physical quantity (TE) is matched with the restricted endothermic target value (TEO), the heating capacity of the radiator (22) or the related relation Adjusting the discharge capacity of the compressor (21) and the pressure reduction amount of the second pressure reducing means (50) so that the physical quantity value (TAV) matches the heating target value (TAO) that can sufficiently heat the external fluid. Can do. That is, even if the refrigerant circulation flow rate is determined by the restriction of the heat absorption capability of the evaporator (27), the refrigerant evaporated in the evaporator (27) is once decompressed by the second decompression means (50), and the second decompression means (50 ) Isentropically compressed by the compressor (21), so that the refrigerant flowing into the radiator (22) is more compressed than when the refrigerant evaporated by the evaporator is compressed without reducing the pressure. Enthalpy can be increased. Thereby, the heating capacity of the radiator (22) or the value (TAV) of the related physical quantity can be set to the heating target value (TAO) that can sufficiently heat the external fluid. Thus, even if there is a restriction on the heat absorption capability of the evaporator (27), it is possible to obtain a sufficient external fluid heating capability in the radiator (22).

In the invention according to claim 2,
Control means (10) for controlling the discharge capacity of the compressor (21) based on the heating capacity of the radiator (22) or the value of its related physical quantity (TAV),
The second pressure reducing means (51) is a constant pressure valve (51) that prevents the refrigerant pressure in the evaporator (27) from becoming less than a predetermined pressure even when the suction refrigerant pressure of the compressor (21) decreases,
The control means (10) controls the discharge capacity of the compressor (21) so that the heating capacity of the radiator (22) or the value of the related physical quantity (TAV) matches the heating target value (TAO),
The second depressurization means (51) is characterized in that the depressurization amount is adjusted so that the endothermic capacity of the evaporator (27) or the value (TE) of the related physical quantity matches the endothermic target value (TEO).

  According to this, the discharge capacity of the compressor (21) is controlled by the control means (10) so that the heating capacity of the radiator (22) or the value (TAV) of the related physical quantity matches the heating target value (TAO). Then, the second pressure reducing means (51), which is a constant pressure valve, adjusts the amount of pressure reduction so that the endothermic capacity of the evaporator (27) or its related physical quantity value (TE) matches the endothermic target value (TEO). Can do. Therefore, the control means (10) does not need to perform the pressure reduction amount control of the second pressure reduction means (51), so that the control logic can be simplified.

In the invention according to claim 3,
Based on the heating capacity of the radiator (22) or its related physical quantity (TAV) and the endothermic capacity of the evaporator (27) or its related physical quantity (TE), the discharge capacity of the compressor (21) Control means (10) for controlling and controlling the amount of pressure reduction of the second pressure reducing means (50),
The control means (10) includes a discharge capacity of the compressor (21) and a second pressure reducing means (second pressure reducing means (20) so that the heating capacity of the radiator (22) or the value (TAV) of the related physical quantity matches the heating target value (TAO). 50) is controlled so that the endothermic capacity of the evaporator (27) or the value (TE) of the related physical quantity (TE) matches the endothermic target value (TEO). 2 It is characterized by controlling the other pressure reduction amount of the pressure reduction means (50).

  According to this, in the control means (10), the discharge capacity and the first capacity of the compressor (21) are adjusted so that the heating capacity of the radiator (22) or the value of the related physical quantity (TAV) matches the heating target value (TAO). 2 Controlling one of the pressure reduction amounts of the pressure reduction means (50), the endothermic capacity of the evaporator (27) or the value of the related physical quantity (TE) of the compressor (21) so as to coincide with the endothermic target value (TEO). The other of the discharge capacity and the pressure reduction amount of the second pressure reducing means (50) can be controlled. Therefore, it is easy to ensure the adjustment accuracy of the discharge capacity of the compressor (21) and the adjustment accuracy of the pressure reduction amount of the second pressure reducing means (50).

In the invention according to claim 4,
The second pressure reducing means (52, 53) includes a fixed throttle valve (52) having a fixed throttle, and an on-off valve (53) provided in parallel to the fixed throttle valve (52) to switch between an open state and a closed state. Consists of
The control means (10) controls the amount of pressure reduction of the second pressure reducing means (52, 53) by switching the open / close state of the on-off valve (52).

  According to this, the pressure reducing amount variable type second pressure reducing means (52, 53) is simply constituted by the fixed throttle valve (52) and the on-off valve (53), and the pressure reducing level by the second pressure reducing means (52, 53). Can be varied in two steps.

In the invention according to claim 5,
The radiator (22) and the evaporator (27) are disposed in the duct (2) through which the air blown into the room flows so that the evaporator (27) is on the upstream side of the air flow,
The evaporator (27) absorbs heat from the air and dehumidifies it, and the radiator (22) heats the air.

  According to this, the room can be easily dehumidified and heated by the air conditioner that blows air into the room from the duct (2), and it is easy to improve the heating capacity at the time of dehumidifying and heating.

  In addition, the code | symbol in the parenthesis attached | subjected to each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

It is a schematic diagram which shows schematic structure of the vehicle air conditioner using the refrigerating-cycle apparatus (refrigeration cycle 3) in 1st Embodiment to which this invention is applied. 3 is a flowchart showing basic control processing by the air conditioning control device 10. It is a graph explaining the operation mode determination of an air conditioner. It is a schematic diagram which shows the air conditioner at the time of the air_conditionaing | cooling operation in 1st Embodiment. It is a schematic diagram which shows the air conditioner at the time of the heating operation in 1st Embodiment. It is a schematic diagram which shows the air conditioning apparatus at the time of the dehumidification heating operation in 1st Embodiment. It is a flowchart which shows the flow of control of step 220 of FIG. 2 in 1st Embodiment. It is a graph explaining the heating capability determination in the condenser. It is a Mollier diagram explaining the heating capability improvement effect in the condenser. It is a flowchart which shows the flow of control of step 220 of FIG. 2 in 2nd Embodiment. It is a graph explaining the dehumidification capability determination in the evaporator 27. FIG. It is a schematic diagram which shows schematic structure of the vehicle air conditioner using the refrigerating-cycle apparatus (refrigeration cycle 3A) in 3rd Embodiment. It is a flowchart which shows the flow of control of step 220 of FIG. 2 in 3rd Embodiment. It is a schematic diagram which shows schematic structure of the vehicle air conditioner using the refrigerating-cycle apparatus (refrigeration cycle 3B) in 4th Embodiment. It is a flowchart which shows the flow of control of step 220 of FIG. 2 in 4th Embodiment. It is a schematic diagram which shows schematic structure of the vehicle air conditioner using the refrigerating-cycle apparatus (refrigeration cycle 3C) in other embodiment. It is a schematic diagram which shows the air conditioning apparatus at the time of the cooling operation in other embodiment. It is a schematic diagram which shows the air conditioner at the time of heating operation in other embodiment. It is a schematic diagram which shows the air conditioner at the time of the dehumidification heating operation in other embodiment. It is a flowchart which shows the flow of control of step 220 of FIG. 2 in other embodiment. It is a Mollier diagram explaining the heating capability improvement effect of the condenser 22 in other embodiment. It is a flowchart which shows the flow of control of step 220 of FIG. 2 in other embodiment. It is a schematic diagram which shows schematic structure of the vehicle air conditioner using the refrigerating-cycle apparatus (refrigeration cycle 3D) in other embodiment. It is a schematic diagram which shows the air conditioning apparatus at the time of the cooling operation in other embodiment. It is a schematic diagram which shows the air conditioner at the time of heating operation in other embodiment. It is a schematic diagram which shows the air conditioner at the time of the dehumidification heating operation in other embodiment. It is a flowchart which shows the flow of control of step 220 of FIG. 2 in other embodiment. It is a Mollier diagram explaining the heating capability improvement effect of the condenser 22 in other embodiment. It is a flowchart which shows the flow of control of step 220 of FIG. 2 in other embodiment.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. In the case where only a part of the configuration is described in each embodiment, the other parts of the configuration are the same as those described previously. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination is not particularly troublesome.

(First embodiment)
FIG. 1 is a schematic diagram showing a schematic configuration of a vehicle air conditioner using a refrigeration cycle apparatus according to a first embodiment to which the present invention is applied.

  The vehicle air conditioner of the present embodiment illustrated in FIG. 1 includes an air conditioning control device (air conditioner control device, control) for each air conditioner (actuator) in an air conditioning unit (air conditioner unit) 1 that air-conditions the interior of a vehicle such as an automobile. Corresponding to means: an auto air conditioner for automobiles configured to be controlled by 10. The air conditioning unit 1 includes an air duct 2 (corresponding to a duct) that forms an air passage that guides conditioned air into the vehicle interior of the automobile, and a centrifugal blower that generates an air flow toward the vehicle interior in the air duct 2. , An evaporator 27 for cooling the air flowing in the air duct 2 (corresponding to an evaporator, hereinafter sometimes referred to as an evaporator), and a condenser 22 for reheating the air that has passed through the evaporator 27 (corresponding to a radiator) And a refrigeration cycle 3 (corresponding to a refrigeration cycle apparatus).

  The air duct 2 is disposed on the front side in the interior of the automobile. On the upstream side of the air flow direction of the air duct 2, the inside air inlet 11 for taking in the cabin air (hereinafter sometimes referred to as “inside air”) and the outside air for taking in the outside air (hereinafter also referred to as “outside air”). A suction port 12 is formed. An inside / outside air switching door 4 is rotatably supported on the air passage side of the inside air suction port 11 and the outside air suction port 12. The inside / outside air switching door 4 is driven by an actuator such as a servo motor to switch the suction port mode to an outside air introduction (FRS) mode, an inside air circulation (REC) mode, or the like.

  A plurality of air outlets (not shown) are formed on the downstream side of the air duct 2 in the air flow direction. A plurality of air outlets are at least a defroster (DEF) air outlet for blowing mainly hot air toward the inner surface of the window glass of the automobile, and a face for mainly blowing cold air toward the upper body (head and chest) of the passenger (FACE) A blowout port and a foot (FOOT) blowout port for mainly blowing warm air toward the lower body (foot portion) of the occupant are provided. The plurality of air outlets are selectively opened and closed by a plurality of mode switching doors (not shown). The plurality of mode switching doors are driven by an actuator such as a servo motor to change the outlet mode (MODE) to the face (FACE) mode, the bi-level (B / L) mode, the foot (FOOT) mode, and the foot differential (F / D) Switch to mode, defroster (DEF) mode.

  The centrifugal blower 5 includes a centrifugal fan that is rotatably accommodated in a scroll casing that is integrally formed on the upstream side of the air flow direction of the blower duct 2, and a blower motor that rotationally drives the centrifugal fan. Then, by changing the rotation speed of the blower motor based on the blower motor terminal voltage (blower control voltage, blower level) applied via a blower drive circuit (not shown), the amount of conditioned air flowing toward the vehicle interior is controlled. The

  The refrigeration cycle 3 includes a compressor 21 (corresponding to a compressor and may be referred to as a compressor hereinafter), a condenser 22, a first pressure reducing unit, an outdoor heat exchanger 24, a second pressure reducing unit, an evaporator 27, an accumulator 28, and these. Is formed with refrigerant pipes or the like that are connected in a ring shape. The compressor 21 is an electric refrigerant compressor that is rotationally driven by a built-in drive motor (not shown) and compresses and discharges the refrigerant gas sucked from the evaporator 27. The compressor 21 operates when energized (ON) and stops when energization is stopped (OFF). Then, the rotation speed of the compressor 21 is controlled by an inverter so that the target rotation speed calculated by the ECU 10 is obtained.

  The condenser 22 is a heating heat exchanger that is disposed in the air duct 2 on the downstream side of the evaporator 27 in the air flow direction and heats the air passing through heat exchange with the refrigerant gas flowing in from the compressor 21. is there. An air mix (A / M) that adjusts the temperature of air blown out into the passenger compartment by adjusting the amount of air passing through the condenser 22 and the amount of air bypassing the condenser 22 at the air inlet of the condenser 22. ) The door 6 is rotatably supported. The A / M door 6 is driven by an actuator such as a servo motor.

  The first decompression unit is configured by a heating variable throttle valve 23 (corresponding to the first decompression means) into which the refrigerant condensed in the condenser 22 flows. The heating variable throttle valve 23 is a pressure reducing device that depressurizes the refrigerant flowing out of the condenser 22 in accordance with the valve opening, and the heating electric expansion valve (EVH) whose valve opening is electrically controlled by the ECU 10. Is used. Further, the heating variable throttle valve 23 can be set to a fully open mode in which the valve opening is fully opened under the control of the ECU 10.

  In the refrigerant pipe connecting the refrigerant outlet of the condenser 22 and the refrigerant inlet of the heating variable throttle valve 23, pressure detection for detecting refrigerant pressure in the refrigerant pipe (refrigerant pressure in the condenser 22, high-pressure side refrigerant pressure). A refrigerant pressure sensor 42 as means is provided. The refrigerant pressure sensor 42 outputs the detected pressure information to the ECU 10.

  The outdoor heat exchanger 24 is installed outside the air duct 2, for example, in a place (specifically, the front part of the engine room) that is susceptible to traveling wind generated when the automobile travels, and illustrated as a refrigerant flowing inside. Heat is exchanged with outdoor air (outside air) blown by an electric fan that does not. The outdoor heat exchanger 24 is operated as a heat absorber that absorbs heat from the outside air in the heating mode or the dehumidifying mode, and is operated as a radiator that radiates heat to the outside air in the cooling mode or the dehumidifying mode.

  The second decompression unit bypasses the cooling variable throttle valve 26 and the evaporator 27 for the cooling variable throttle valve 26 into which the refrigerant flows from the outdoor heat exchanger 24 and the cooling heat flows out from the outdoor heat exchanger 24 to the accumulator 28. It is comprised by the bypass piping 33 etc. for sending. The cooling variable throttle valve 26 is a second pressure reducing device that depressurizes the refrigerant flowing out of the outdoor heat exchanger 24 according to the valve opening degree. The electric expansion for cooling whose valve opening degree is electrically controlled by the ECU 10. A valve (EVC) is used. The variable throttle valve for cooling 26 can be set to a fully closed mode in which the valve opening is fully closed under the control of the ECU 10.

  The bypass pipe 33 opens when energized (ON), and closes when the energization is stopped (OFF). An electromagnetic on-off valve (VH: hereinafter sometimes referred to as heating solenoid valve) 34. Is installed.

  The evaporator 27 evaporates and evaporates the refrigerant depressurized by the cooling variable throttle valve 26 by heat exchange with the air as the heat-absorbing external fluid blown by the centrifugal fan 5, and causes the refrigerant to be sent to the compressor 21 via the accumulator 28. It is an air-refrigerant heat exchanger (heat absorber) for supplying gas. The evaporator 27 (specifically, an outer fin thermally connected to the refrigerant pipe of the evaporator 27) is an evaporator outer surface temperature sensor (evaporator fin) that is a temperature detecting means for detecting the temperature of the outer surface of the evaporator 27. 45, which may be referred to as a temperature sensor, hereinafter referred to as an “eva temperature sensor”). The EVA temperature sensor 45 outputs the detected temperature information to the ECU 10.

  The accumulator 28 is a gas-liquid separator having a storage chamber for temporarily storing the refrigerant that has flowed in from the evaporator 27.

  In the refrigeration cycle 3 of the present embodiment, an intake refrigerant throttle valve 50 (corresponding to a second decompression unit) that decompresses the refrigerant evaporated by the evaporator 27 and sucked into the compressor 21 via the accumulator 28 is disposed. The suction refrigerant throttle valve 50 is a decompression device that decompresses the refrigerant flowing out of the evaporator 27 in accordance with the valve opening, and an electric expansion valve whose valve opening is electrically controlled by the ECU 10 is used. The intake refrigerant throttle valve 50 can be set to a fully open mode in which the valve opening is fully opened under the control of the ECU 10. Specifically, the suction refrigerant throttle valve 50 is provided in a part upstream of the downstream connection point of the bypass pipe 33 in the refrigerant pipe connecting the refrigerant outlet of the evaporator 27 and the refrigerant inlet of the accumulator 28. .

  Here, the circulation circuit switching means of the refrigeration cycle 3 includes an operation mode of the refrigeration cycle 3, that is, a circulation path of the refrigerant in the refrigeration cycle 3, a cooling mode circulation circuit (cooling cycle), and a heating mode circulation circuit (heating cycle). ), Switching to any cycle of the circulation circuit (dehumidification cycle) for the dehumidification mode (dehumidification heating mode). In this embodiment, the variable throttle valve for heating 23 and the variable throttle valve for cooling 26 that can set the full open mode. The heating solenoid valve 34 corresponds to the circulation circuit switching means.

  More specifically, the heating variable throttle valve 23 is in a fully open mode, the heating solenoid valve 34 is closed, and the cooling variable throttle valve 26 is set to a flow control opening degree for decompressing and expanding the refrigerant (decompressing expansion mode). 4), the refrigerant circulates as shown by the solid line in FIG. 4, and the operation mode of the refrigeration cycle 3 becomes the cooling cycle (cooling mode circulation circuit). In the cooling operation mode, the suction refrigerant throttle valve 50 is in the fully open mode. Further, the air mix door 6 closes the air inlet portion of the condenser 22, and the condensation of the refrigerant in the condenser 22 is suppressed.

  The heating variable throttle valve 23 has a flow control opening degree for decompressing and expanding the refrigerant (decompressing expansion mode), the heating electromagnetic valve 34 is opened, and the cooling variable throttle valve 26 is in the fully closed mode. As shown by a solid line in FIG. 5, the refrigerant circulates, and the operation mode of the refrigeration cycle 3 becomes a heating cycle (heating mode circulation circuit). In the heating operation mode, the air mix door 6 opens the air inlet of the condenser 22, and air, which is an external fluid, is heated as the refrigerant condenses in the condenser 22.

  The heating variable throttle valve 23 has a flow control opening degree for decompressing and expanding the refrigerant (becomes a decompression and expansion mode), and the heating electromagnetic valve 34 is closed, whereby the refrigerant circulates as shown by a solid line in FIG. The operation mode of cycle 3 is a dehumidifying heating cycle (circulation circuit for dehumidifying heating mode). In the dehumidifying and heating operation mode, when the air heating capacity in the condenser 22 may be small, the cooling variable throttle valve 26 has a flow control opening degree for decompressing and expanding the refrigerant (becomes a decompression and expansion mode), and suction The refrigerant throttle valve 50 is in the fully open mode.

  On the other hand, when the air heating capacity in the condenser 22 is increased, the cooling variable throttle valve 26 is in the fully open mode, and the suction refrigerant throttle valve 50 has a flow control opening degree for decompressing and expanding the refrigerant (decompressing expansion). Mode). In any case, the air mix door 6 opens the air inlet of the condenser 22. As a result, the air that has been dehumidified by being condensed and removed by the water vapor that has been cooled by the evaporator 27 is reheated as the refrigerant condenses in the condenser 22. The control of the suction refrigerant throttle valve 50 in the dehumidifying and heating operation mode will be described in detail later.

  The ECU 10 includes functions such as a CPU that performs control processing and arithmetic processing, memories (ROM, RAM) that store various programs and data, an I / O port, a timer, and the like. Has a built-in computer.

  When the ignition switch is turned on (the start switch that enables the vehicle to travel is turned on), the ECU 10 is supplied with ECU power, an operation signal from an air conditioner operation panel (not shown), refrigerant pressure, etc. Based on sensor signals from various sensors including the sensor 42 and the temperature sensor 45 and a control program stored in the memory, each actuator of the air conditioning unit 1 (servo motor of each door, blower motor of the blower 5, each variable throttle) The valves 23, 26, 50, the electromagnetic valve 34, the inverter of the compressor 21, etc.) are electrically controlled.

  Next, based on the said structure, the action | operation of the vehicle air conditioner using the refrigerating cycle 3 of this embodiment is demonstrated.

  Here, FIG. 2 is a flowchart showing basic control processing by the ECU 10.

  First, when the start switch is turned on and DC power is supplied to the ECU 10, the routine of FIG. 2 is started, and each initialization and initial setting are performed in step 110. Next, in step 120, a switch signal is read from each switch such as a temperature setting switch of the air conditioner operation panel. Next, in step 130, sensor signals from the inside air temperature sensor, the outside air temperature sensor, the solar radiation sensor, the refrigerant pressure sensor 42, the evaporation temperature sensor 45, etc. are read.

Next, in step 140, a target blowing temperature TAO of air blown into the vehicle interior is calculated based on the following formula 1 stored in advance in the ROM.
(Equation 1)
TAO = KSET × TSET-KR × TR-KAM × TAM-KS × TS + C
TSET is the set temperature set by the temperature setting switch, TR is the inside air temperature detected by the inside air temperature sensor, TAM is the outside air temperature detected by the outside air temperature sensor, and TS is the amount of solar radiation detected by the solar radiation sensor. . KSET, KR, KAM, and KS are gains, and C is a correction constant.

  When the target outlet temperature TAO is calculated in step 140, the inlet mode and the outlet mode corresponding to the target outlet temperature TAO are determined in step 150 from the characteristic diagram (map) stored in advance in the ROM. In addition, when the air inlet mode and the air outlet mode are set by manual operation on the air conditioner operation panel, the setting mode is determined.

  Next, in step 160, a blower air volume (substantially a voltage applied to the blower motor of the blower 5) corresponding to the target blowout temperature TAO is determined from a characteristic diagram (map) stored in advance in the ROM. When the blower air volume is fixed by manual operation on the air conditioner operation panel, the fixed air volume is determined.

If the blower air volume is determined in step 160, then in step 170, the target door opening degree SW of the air mix door 6 is calculated based on the following formula 2 stored in the ROM in advance.
(Equation 2)
SW = {(TAO-TE) / (TAV-TE)} × 100 (%)
TE is an evaporator temperature detected by the evaporator temperature sensor 45 (hereinafter sometimes referred to as an evaporator temperature or an evaporator surface temperature), and TAV is obtained (calculated) based on the refrigerant pressure detected by the refrigerant pressure sensor 42. Condenser temperature.

  When calculated as SW ≦ 0 (%), the air mix door 6 is controlled to a position (MAXCOOL position) in which all of the cold air from the evaporator 27 is bypassed from the condenser 22. When calculated as SW ≧ 100 (%), the air mix door 6 is controlled to a position (MAXHOT position) through which all the cold air from the evaporator 27 passes through the condenser 22. Further, when calculated as 0 (%) <SW <100 (%), the air mix door 6 passes a part of the cool air from the evaporator 27 through the condenser 22 and bypasses the rest of the cool air from the condenser 22. Controlled to an intermediate position.

  Next, the process proceeds to step 180, and a target evaporator temperature (hereinafter sometimes referred to as a target evaporator temperature or a target evaporator surface temperature) TEO for driving and controlling the compressor 21 is calculated. In step 180, the evaporator 27 required for executing each control such as temperature adjustment control, comfortable humidity control, and anti-fogging control when air conditioning the vehicle interior is performed from a characteristic diagram (map) stored in advance in the ROM. A target evaporation temperature TEO, which is the outer surface temperature of, is calculated.

  When the target evaporation temperature TEO is calculated in step 180, the operation mode of the refrigeration cycle 3 is determined in step 190 according to the target blowing temperature TAO. In step 190, for example, as shown in FIG. 3, the target blowing temperature TAO calculated in step 140 is compared with the first predetermined temperature α and the second predetermined temperature β higher than the first predetermined temperature α, and the target blowing temperature TAO. Is less than α, greater than β, or between α and β.

  If it is determined in step 190 that the target outlet temperature TAO is equal to or lower than the first predetermined temperature α, the routine proceeds to step 200, where the cooling operation of the refrigeration cycle 3 is set. As described above, a cooling cycle in which the heating variable throttle valve 23 is fully opened, the heating solenoid valve 34 is closed, the cooling variable throttle valve 26 is set to the refrigerant flow control opening degree, and the intake refrigerant throttle valve 50 is fully opened. Is set.

  If it is determined in step 190 that the target outlet temperature TAO is equal to or higher than the second predetermined temperature β, the process proceeds to step 210, and the refrigeration cycle 3 is set to perform the heating operation. As described above, the heating cycle is set so that the heating variable throttle valve 23 is set to the refrigerant flow control opening, the heating electromagnetic valve 34 is opened (fully opened), and the cooling variable throttle valve 26 is fully closed. Is called.

  If it is determined in step 190 that the target outlet temperature TAO is higher than the first predetermined temperature and lower than the second predetermined temperature β, the routine proceeds to step 220, where the refrigeration cycle 3 is set to perform dehumidifying heating operation. Here, FIG. 7 is a flowchart showing a flow of control in step 220 in FIG.

  When executing step 220, as shown in FIG. 7, first, the evaporator temperature TE detected by the evaporator temperature sensor 45 is matched with the target evaporator temperature TEO calculated in step 180 (so that it is approximated as much as possible). Rotation control of the compressor 21 (that is, control of refrigerant discharge capacity) is performed (step 221).

  If step 221 is executed, it is next determined whether or not the control flag of the intake refrigerant throttle valve 50 is 1 (step 222). When the control flag of the suction refrigerant throttle valve 50 is 1, suction is performed so that the condenser temperature TAV obtained based on the refrigerant pressure detected by the refrigerant pressure sensor 42 matches the target blowout temperature TAO (as close as possible). The opening degree of the refrigerant flow through which the refrigerant throttle valve 50 passes is controlled, and when the control flag of the suction refrigerant throttle valve 50 is 0, the refrigerant flow through which the suction refrigerant throttle valve 50 passes is not fully throttled. It is a setting.

  If it is determined in step 222 that the control flag of the intake refrigerant throttle valve 50 is not 1, that is, the control flag is 0, the condenser temperature TAV obtained based on the refrigerant pressure detected by the refrigerant pressure sensor 42 is the target. The opening adjustments of the heating variable throttle valve 23 and the cooling variable throttle valve 26 are performed so as to coincide with the blowout temperature TAO (as close as possible) (step 223).

  As a result of executing Step 223, the cooling variable throttle valve 26 is opened to reach the fully opened state, and the cooling variable throttle valve 26 is fully opened to condense even in a state where the heat absorption capacity of the outdoor heat exchanger 24 is maximized. It is determined whether or not the heating capacity in the vessel 22 is insufficient (step 224). In Step 224, even if Step 223 is executed to control the condenser temperature TAV so as to coincide with the target blowing temperature TAO, the condenser temperature TAV cannot be raised to the target blowing temperature TAO, as shown in FIG. In addition, it is determined whether the heating capacity is insufficient.

  Even if the cooling variable throttle valve 26 is not fully opened in step 224, the heating capacity in the condenser 22 is not insufficient, or if the cooling variable throttle valve 26 is fully opened, the heating capacity in the condenser 22 is not insufficient. If it is determined, the process returns with the control flag of the suction refrigerant throttle valve 50 kept at 0 (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 224 that the heating capacity of the condenser 22 is insufficient even when the cooling variable throttle valve 26 is fully opened, that is, the outdoor heat exchanger 24 is replaced with an evaporator (heat absorber) having the same refrigerant pressure as the evaporator 27. ), If it is determined that the heating capacity in the condenser 22 is insufficient, the control flag of the intake refrigerant throttle valve 50 is set to 1 (step 225), and the process returns (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 222 that the control flag of the intake refrigerant throttle valve 50 is 1, the intake refrigerant throttle valve 50 is opened so that the condenser temperature TAV matches the target outlet temperature TAO (as close as possible). The degree is adjusted (step 226).

  As a result of executing Step 226, it is determined whether or not the heating capacity in the condenser 22 is excessive even when the intake refrigerant throttle valve 50 is opened to reach the fully open state and the intake refrigerant throttle valve 50 is in the fully open state. (Step 227). In Step 227, even if Step 226 is executed to control the condenser temperature TAV so as to match the target blowing temperature TAO, the condenser temperature TAV cannot be lowered to the target blowing temperature TAO, as shown in FIG. Determine if the heating capacity is excessive.

  In step 227, the heating capacity in the condenser 22 is not excessive even if the suction refrigerant throttle valve 50 is not fully opened, or the heating capacity in the condenser 22 is not excessive if the suction refrigerant throttle valve 50 is fully opened. If it is determined, the process returns with the control flag of the suction refrigerant throttle valve 50 being set to 1 (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 227 that the heating capacity of the condenser 22 is excessive even when the intake refrigerant throttle valve 50 is fully opened, the control flag of the intake refrigerant throttle valve 50 is set to 0 (step 228), and the process returns ( Proceed to step 230 shown in FIG.

  The setting for performing the cooling operation of the refrigeration cycle 3 in step 200 shown in FIG. 2, the setting for performing the heating operation of the refrigeration cycle 3 in step 210, and dehumidifying the refrigeration cycle 3 in step 220 shown in FIG. 2 described using the control flow in FIG. When one of the settings for the heating operation is executed, the control state of the compressor 21 is determined so that the detected temperature TE of the evaporation temperature sensor 45 becomes the set target post-evaporation temperature TEO (step 230). That is, in step 230, the state of the rotation control (control of the refrigerant discharge capacity) of the compressor 21 performed in step 221 of FIG. 7 is set.

  Next, a control signal is output so that each control state calculated or determined in each of the above steps 150, 160, 170, 220, 210, 220, 230 is obtained (step 240). Then, the process returns to step 120.

  According to the above-described configuration and operation, when the cooling operation of step 200 is set by the determination of step 190, as described above, the refrigerant circulates through the path of the solid line shown in FIG. Air is cooled by the evaporator 27 and blown out into the passenger compartment. The amount of heat absorbed by the evaporator 27 and the amount of enthalpy increase due to the refrigerant adiabatic compression of the compressor 21 are radiated to the outside air by the outdoor heat exchanger 24.

  When the heating operation of step 210 is set by the determination of step 190, as described above, the refrigerant circulates through the path of the solid line shown in FIG. 5, and the air flowing through the air duct 2 is heated by the condenser 22, Blow out into the passenger compartment. The amount of heat radiated to the air by the condenser 22 is covered by the amount of heat absorbed from the outside air by the outdoor heat exchanger 24 and the amount of heat by the enthalpy increase due to the refrigerant adiabatic compression of the compressor 21.

  When the dehumidifying and heating operation of step 220 is set by the determination of step 190, as described above, the refrigerant circulates through the path of the solid line shown in FIG. 6, and the air flowing through the air duct 2 is cooled by the evaporator 27. Is dehumidified, reheated by the condenser 22 and blown out into the passenger compartment. The amount of heat absorbed from the air flowing through the blower duct 2 in the evaporator 27 and the amount of enthalpy increase due to the refrigerant adiabatic compression of the compressor 21 (increased heat amount due to compression power) are air flowing through the blower duct 2 by the condenser 22. The heat is dissipated. The difference between the heat absorption amount in the evaporator 27 and the heat amount due to the increase in enthalpy by the compressor 21 and the heat release amount in the condenser 22 is compensated by the heat absorption amount or heat release amount in the outdoor heat exchanger 24.

  The refrigeration cycle 3 of the present embodiment includes a variable pressure reduction type intake refrigerant throttle valve 50 that depressurizes the refrigerant that is evaporated by the evaporator 27 and sucked by the compressor 21. If the sum of the heat absorption amount in the evaporator 27, the heat absorption amount in the outdoor heat exchanger 24, and the heat amount due to the increase in enthalpy by the compressor 21 is insufficient for the heat dissipation amount in the condenser 22, the suction refrigerant throttle The refrigerant is depressurized by the valve 50, and the amount of heat for the increase in enthalpy by the compressor 21 is increased by increasing the amount of work for adiabatically compressing the depressurized refrigerant by the compressor 21, so that the heat dissipation in the condenser 22 is insufficient. The amount of heat can be secured.

  As described with reference to FIG. 7, the ECU 10 controls the discharge capacity of the compressor 21 so that the value of the evaporator temperature TE, which is a related physical quantity of the endothermic capacity of the evaporator 27, matches the target evaporator temperature TEO which is the endothermic target value. Then, the pressure reduction amount of the suction refrigerant throttle valve 50 is controlled so that the value of the condenser temperature TAV that is a related physical quantity of the heating capacity of the condenser 22 coincides with the target blowing temperature TAO that is the heating target value.

  Thereby, even if the evaporator temperature TE is made to coincide with the target evaporator temperature TEO (for example, 1 ° C.) having restrictions for preventing frost of the evaporator 27, for example, the temperature TAV of the condenser 22 circulates in the air duct 2. The refrigerant discharge capacity of the compressor 21 and the pressure reduction amount of the suction refrigerant throttle valve 50 can be controlled so as to coincide with the target blowing temperature TAO that can sufficiently heat the air.

  In other words, it is the cycle refrigerant circulation flow rate determined by the restriction of the heat absorption capacity of the evaporator 27, and even if the heat absorption capacity of the outdoor heat exchanger 24 is maximized by fully opening the cooling variable throttle valve 26, the heating capacity in the condenser 22 Is insufficient, a cycle state as shown by a solid line in the pressure-enthalpy diagram of FIG. 9 can be formed.

  Specifically, the refrigerant evaporated by the evaporator 27 is once depressurized by the suction refrigerant throttle valve 50, and the refrigerant depressurized by the suction refrigerant throttle valve 50 is isentropically compressed by the compressor 21 and flows into the condenser 22. Enthalpy can be increased.

  A cycle indicated by a broken line in the pressure-enthalpy diagram of FIG. 9 is a comparative example in which the refrigerant that has not been provided with the suction refrigerant throttle valve 50 is compressed by the compressor 21 without being depressurized by the evaporator 27.

  According to the refrigeration cycle 3 of the present embodiment, even if the heat absorption capability of the outdoor heat exchanger 24 is maximized, even if the heating capability in the condenser 22 is insufficient, the refrigerant is decompressed by the intake refrigerant throttle valve 50, By increasing the amount of work for compressing and discharging the refrigerant decompressed by the suction refrigerant throttle valve 50 by the compressor 21, the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the condenser 22, is circulated in the air duct 2. The target blowing temperature TAO, which is a heating target value that can sufficiently heat the air, can be obtained. In this way, even if the heat absorption capability of the evaporator 27 is limited, a sufficient external fluid heating capability can be obtained in the condenser 22.

  In other words, when the condenser 22 requires a large heating capacity, the relationship between the amount of heat in the dehumidifying heating cycle is the heating amount of the condenser 22 (heating capacity) = the evaporator 27. The heat absorption amount (dehumidification ability, heat absorption ability) + compression power of the compressor 21 + heat absorption quantity of the outdoor heat exchanger 24.

  Here, considering the prevention of the frost of the evaporator 27, the evaporation pressure of the evaporator 27 has a lower limit. Further, the evaporation pressure of the outdoor heat exchanger 24 upstream of the refrigerant flow of the evaporator 27 has a similar lower limit. Therefore, particularly when the outside air temperature is low or when the load on the evaporator 27 is low, the heat absorption amount of the evaporator 27 and the outdoor heat exchanger 24 cannot be obtained sufficiently. Further, the compression power of the compressor 21 is uniquely determined by controlling the dehumidifying ability of the evaporator 27. Due to the above factors, if the suction refrigerant throttle valve 50 is not used, the heating capacity cannot be improved under the condition that the heating capacity in the condenser 22 does not reach the required value.

  On the other hand, the refrigeration cycle 3 according to the present embodiment includes a variable intake pressure reducing refrigerant throttle valve 50 that decompresses the refrigerant evaporated by the evaporator 27 and sucked by the compressor 21. The arrangement of the suction refrigerant throttle valve 50 is intended to improve the heating capacity of the condenser 22 by increasing the compression power of the compressor 21 while maintaining the dehumidifying capacity of the evaporator 27.

  In the present embodiment, even if the required dehumidifying capacity of the evaporator 27 is controlled by the rotation speed of the compressor 21, if the condenser 22 does not reach the required heating capacity, the opening degree of the suction refrigerant throttle valve 50 is throttled. Then, the evaporation pressure of the evaporator 27 increases and the suction pressure of the compressor 21 decreases. At this time, in order to maintain the dehumidifying capacity, the rotation speed of the compressor 21 is increased to control the evaporation pressure, that is, the refrigerant flow rate to be constant. In this way, even if the heat absorption capability (dehumidification capability) of the evaporator 27 is limited, a sufficient external fluid heating capability can be obtained in the condenser 22.

  Further, both the adjustment of the discharge capacity of the compressor 21 that matches the evaporator temperature TE with the target evaporator temperature TEO and the adjustment of the pressure reduction amount of the suction refrigerant throttle valve 50 that matches the condenser temperature TAV with the target outlet temperature TAO are controlled. This is performed by the ECU 10 as means. Therefore, it is easy to ensure the adjustment accuracy of the discharge capacity of the compressor 21 and the adjustment accuracy of the pressure reduction amount of the suction refrigerant throttle valve 50.

(Second Embodiment)
Next, a second embodiment will be described based on FIG. 10 and FIG.

  In the second embodiment, compared to the first embodiment described above, the ECU 10 determines that the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the condenser 22, is the target blowing temperature TAO, which is the heating target value. The discharge capacity of the compressor 21 is controlled so as to coincide with the refrigerant temperature, and the refrigerant temperature of the intake refrigerant throttle valve 50 is adjusted so that the value of the evaporator temperature TE, which is a related physical quantity of the heat absorption capability of the evaporator 27, coincides with the target evaporator temperature TEO which is the endothermic target value. The difference is that the amount of decompression is controlled. In addition, about the part similar to 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 10, in the present embodiment, when performing step 220 shown in FIG. 2, first, the condenser temperature TAV obtained based on the refrigerant pressure detected by the refrigerant pressure sensor 42 is the target outlet temperature TAO. The rotation control of the compressor 21 (that is, the control of the refrigerant discharge capacity) is performed so as to match (as close as possible) (step 221a).

  If step 221a is executed, it is next determined whether or not the control flag of the intake refrigerant throttle valve 50 is 1 (step 222). When the control flag of the intake refrigerant throttle valve 50 is 1, the intake refrigerant throttle valve is set so that the evaporator temperature TE detected by the evaporator temperature sensor 45 matches the target evaporator temperature TEO calculated in step 180 (as close as possible). 50 is a setting in which the opening degree of the refrigerant flow rate through which the refrigerant passes 50 is controlled, and the control flag of the intake refrigerant throttle valve 50 is set to be fully open and not throttled down through the refrigerant flow rate through which the intake refrigerant throttle valve 50 passes. .

  If it is determined in step 222 that the control flag of the intake refrigerant throttle valve 50 is not 1, that is, the control flag is 0, the evaporator temperature TE detected by the evaporator temperature sensor 45 is the target evaporator temperature TEO calculated in step 180. (Step 223a) is performed to adjust the opening degree of the heating variable throttle valve 23 and the cooling variable throttle valve 26 so as to coincide with each other (as close as possible).

  As a result of executing step 223a, the dehumidifying capacity (heat absorption capacity) in the evaporator 27 is excessive even when the variable throttle valve for cooling 26 is opened to reach the fully opened state and the variable throttle valve for cooling 26 is fully opened. (Step 224a). In step 224a, even if step 223a is executed and control is performed so that the evaporation temperature TE coincides with the target evaporation temperature TEO, the evaporation temperature TE cannot be raised to the target evaporation temperature TEO, and as shown in FIG. Determine if the dehumidifying capacity is excessive.

  In step 224a, the dehumidifying capacity in the evaporator 27 does not become excessive even if the variable throttle valve 26 for cooling is not fully opened, or the dehumidifying capacity in the evaporator 27 is excessive if the variable throttle valve 26 for cooling is fully opened. If it is determined that the condition does not occur, the routine returns with the control flag of the intake refrigerant throttle valve 50 kept at 0 (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 224a that the dehumidifying capacity of the evaporator 27 is excessive even when the cooling variable throttle valve 26 is fully opened, that is, the outdoor heat exchanger 24 is an evaporator having the same refrigerant pressure as that of the evaporator 27 ( If it is determined that the dehumidifying capacity of the evaporator 27 is excessive even if it functions as a heat absorber, the control flag of the suction refrigerant throttle valve 50 is set to 1 (step 225), and the process returns (step 230 shown in FIG. 2). Go to).

  When it is determined in step 222 that the control flag of the intake refrigerant throttle valve 50 is 1, the opening degree of the intake refrigerant throttle valve 50 is set so that the evaporation temperature TE matches the target evaporation temperature TEO (as close as possible). Adjustment is performed (step 226a).

  As a result of executing Step 226a, it is determined whether or not the dehumidifying capacity in the evaporator 27 is insufficient even when the suction refrigerant throttle valve 50 is opened and reaches the fully opened state, and the suction refrigerant throttle valve 50 is in the fully opened state. (Step 227a). In step 227a, even if step 226a is executed to control the evaporation temperature TE so as to coincide with the target evaporation temperature TEO, the evaporation temperature TE cannot be lowered to the target evaporation temperature TEO. As shown in FIG. Determine if your ability is insufficient.

  In step 227a, it is determined that the dehumidifying capacity in the evaporator 27 is not insufficient even if the suction refrigerant throttle valve 50 is not fully opened, or that the dehumidifying capacity in the evaporator 27 is not insufficient if the suction refrigerant throttle valve 50 is fully opened. In this case, the process returns with the control flag of the suction refrigerant throttle valve 50 being set to 1 (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 227a that the dehumidifying capacity of the evaporator 27 is insufficient even when the suction refrigerant throttle valve 50 is fully opened, the control flag of the suction refrigerant throttle valve 50 is set to 0 (step 228) and the process returns (FIG. 2). Go to step 230).

  According to the configuration and operation of the present embodiment, the ECU 10 discharges the compressor 21 so that the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the condenser 22, coincides with the target blowing temperature TAO that is the heating target value. The capacity is controlled, and the pressure reduction amount of the suction refrigerant throttle valve 50 is controlled so that the value of the evaporator temperature TE, which is a related physical quantity of the heat absorption capability of the evaporator 27, coincides with the target evaporator temperature TEO, which is the heat absorption target value.

  Even in this way, as in the first embodiment, even if the evaporator temperature TE is made to coincide with the target evaporator temperature TEO (for example, 1 ° C.) having restrictions for preventing frost of the evaporator 27, for example, The refrigerant discharge capacity of the compressor 21 and the pressure reduction amount of the suction refrigerant throttle valve 50 can be controlled so that the temperature TAV matches the target blowing temperature TAO that can sufficiently heat the air flowing through the blower duct 2.

  This is the cycle refrigerant circulation flow rate determined by the restriction of the heat absorption capability of the evaporator 27, and even if the heat absorption capability of the outdoor heat exchanger 24 is maximized by fully opening the cooling variable throttle valve 26, the heating capability in the condenser 22 is insufficient. The cycle state as shown by the solid line in the pressure-enthalpy diagram of FIG. 9 can be formed, and the same effect as in the first embodiment can be obtained.

(Third embodiment)
Next, a third embodiment will be described based on FIG. 12 and FIG.

  The third embodiment differs from the second embodiment described above in that the suction refrigerant throttle valve is a constant pressure valve. In addition, about the part similar to 1st, 2nd embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 12, in the refrigeration cycle 3A of the present embodiment, a suction refrigerant throttle valve 51 (corresponding to a second pressure reducing means) that decompresses the refrigerant evaporated by the evaporator 27 and sucked into the compressor 21 via the accumulator 28. Is arranged. This suction refrigerant throttle valve 51 is an autonomous constant pressure valve (so-called evaporation) that suppresses the refrigerant pressure in the evaporator 27 from becoming less than a predetermined pressure (for example, 0.3 MPa) even if the suction refrigerant pressure of the compressor 21 decreases. Pressure regulating valve).

  Specifically, the suction refrigerant throttle valve 51 is provided in a part upstream of the downstream connection point of the bypass pipe 33 in the refrigerant pipe connecting the refrigerant outlet of the evaporator 27 and the refrigerant inlet of the accumulator 28. .

  As shown in FIG. 13, in the present embodiment, when executing step 220 shown in FIG. 2, first, the condenser temperature TAV obtained based on the refrigerant pressure detected by the refrigerant pressure sensor 42 is the target blowout. Rotation control of the compressor 21 (that is, control of the refrigerant discharge capacity) is performed so as to coincide with the temperature TAO (as close as possible) (step 221a).

  After step 221a is executed, the heating variable throttle valve 23 and the cooling unit are then adjusted so that the evaporation temperature TE detected by the evaporation temperature sensor 45 matches the target evaporation temperature TEO calculated in step 180 (as close as possible). The opening degree of the variable throttle valve 26 is adjusted (step 223a).

  In the present embodiment, even when the above-described step 223a is executed, it is not possible to adjust the opening degrees of the heating variable throttle valve 23 and the cooling variable throttle valve 26 so that the evaporation temperature TE matches the target evaporation temperature TEO. The refrigerant evaporating pressure in the evaporator 27 is adjusted to a predetermined pressure by the function of the suction refrigerant throttle valve 51 that is a constant pressure valve, and the dehumidifying capacity of the evaporator 27 is autonomously set to the predetermined capacity.

  According to the configuration and operation of the present embodiment, the ECU 10 discharges the compressor 21 so that the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the condenser 22, coincides with the target blowing temperature TAO that is the heating target value. The capacity is controlled, and the amount of pressure reduction is made autonomous by the suction refrigerant throttle valve 51, which is a constant pressure valve, so that the evaporator temperature TE, which is a related physical quantity of the heat absorption capability of the evaporator 27, matches the target evaporator temperature TEO, which is the endothermic target value. Adjusted to.

  Therefore, it is the cycle refrigerant circulation flow rate determined by the restriction of the heat absorption capability of the evaporator 27, and even if the heat absorption capability of the outdoor heat exchanger 24 is maximized by fully opening the cooling variable throttle valve 26, the heating capability in the condenser 22 is insufficient. In this case, a cycle state as indicated by a solid line in the pressure-enthalpy diagram of FIG. 9 can be formed, and the same effect as in the first and second embodiments can be obtained.

  Further, since the ECU 10 does not need to perform the pressure reduction control of the suction refrigerant throttle valve 51, the control logic can be simplified.

(Fourth embodiment)
Next, a fourth embodiment will be described based on FIG. 14 and FIG.

  The fourth embodiment is different from the first embodiment in that the variable pressure reduction type second pressure reducing means is composed of a fixed throttle valve and an electromagnetic on-off valve. In addition, about the part similar to 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 14, the refrigeration cycle 3B of the present embodiment bypasses the suction refrigerant throttle valve 52 and the suction refrigerant throttle valve 52 that depressurizes the refrigerant evaporated by the evaporator 27 and sucked into the compressor 21 via the accumulator 28. And an electromagnetic on-off valve 53 provided in the refrigerant pipe. In other words, among the refrigerant pipes that connect the refrigerant outlet of the evaporator 27 and the refrigerant inlet of the accumulator 28, the suction refrigerant throttle valve 52 and the electromagnetic opening / closing valve 53 are located at a position upstream of the downstream connection point of the bypass pipe 33. It is provided in parallel.

  The intake refrigerant throttle valve 52 is a fixed throttle valve, and the electromagnetic on-off valve 53 is an on-off valve that is selectively controlled by the ECU 10 between a fully open state and a fully closed state. The suction refrigerant throttle valve 52 and the electromagnetic on-off valve 53 correspond to the second pressure reducing means in this embodiment.

  Among the refrigerant pipes connecting the refrigerant outlet valve of the suction pipe 52 and the electromagnetic on-off valve 53, specifically, the refrigerant outlet of the evaporator 27 and the refrigerant inlet of the accumulator 28, to the part upstream of the downstream connection point of the bypass pipe 33. Is provided.

  As shown in FIG. 15, in this embodiment, when executing step 220 shown in FIG. 2, first, the evaporator temperature TE detected by the evaporator temperature sensor 45 is equal to the target evaporator temperature TEO calculated in step 180. Rotation control of the compressor 21 (that is, control of the refrigerant discharge capacity) is performed so as to match (as close as possible) (step 221).

  If step 221 is executed, it is next determined whether or not the control flag of the electromagnetic on-off valve 53 is 1 (step 222b). When the control flag of the electromagnetic on-off valve 53 is 1, the opening state of the electromagnetic on-off valve 53 is set to be fully closed, and when the control flag of the potential on-off valve 53 is 0, the opening state of the electromagnetic on-off valve 53 is set. This is a setting for full open control.

  If it is determined in step 222b that the control flag of the electromagnetic on-off valve 53 is not 1, that is, the control flag is 0, the condenser temperature TAV obtained based on the refrigerant pressure detected by the refrigerant pressure sensor 42 is the target blowout. The opening adjustments of the heating variable throttle valve 23 and the cooling variable throttle valve 26 are performed so as to coincide with the temperature TAO (as close as possible) (step 223).

  As a result of executing Step 223, whether or not the heating capacity of the condenser 22 is insufficient even when the cooling variable throttle valve 26 is opened to reach the fully opened state and the cooling variable throttle valve 26 is fully opened. Judgment is made (step 224). In Step 224, even if Step 223 is executed to control the condenser temperature TAV so as to coincide with the target blowing temperature TAO, the condenser temperature TAV cannot be raised to the target blowing temperature TAO, as shown in FIG. In addition, it is determined whether the heating capacity is insufficient.

  Even if the cooling variable throttle valve 26 is not fully opened in step 224, the heating capacity in the condenser 22 is not insufficient, or if the cooling variable throttle valve 26 is fully opened, the heating capacity in the condenser 22 is not insufficient. If it is determined, the process returns with the control flag of the electromagnetic on-off valve 53 kept at 0 (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 224 that the heating capacity of the condenser 22 is insufficient even when the cooling variable throttle valve 26 is fully opened, that is, the outdoor heat exchanger 24 is replaced with an evaporator (heat absorber) having the same refrigerant pressure as the evaporator 27. ), If it is determined that the heating capacity in the condenser 22 is insufficient, the control flag of the electromagnetic on-off valve 53 is set to 1 (step 225b), and the process returns (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 222b that the control flag of the electromagnetic on-off valve 53 is 1, the electromagnetic on-off valve 53 is fully closed (step 226b). Then, it is determined whether or not the heating capacity in the condenser 22 is excessive with the electromagnetic on-off valve 53 fully closed (step 227b). In step 227b, even if the electromagnetic on-off valve 53 is closed and the refrigerant is depressurized by the fixed throttle suction refrigerant throttle valve 52, the condenser temperature TAV cannot be lowered to the target outlet temperature TAO. As shown in FIG. Determine whether is excessive.

  If it is determined in step 227b that the heating capacity of the condenser 22 does not become excessive even when the electromagnetic on-off valve 53 is fully closed, the control is returned with the control flag of the electromagnetic on-off valve 53 set to 1 (see FIG. 2). Go to step 230 shown).

  In step 227b, when it is determined that the heating capacity of the condenser 22 is excessive when the electromagnetic on-off valve 53 is fully closed, the control flag of the electromagnetic on-off valve 53 is set to 0 (step 228b) and the process returns (FIG. (Proceed to step 230 shown in FIG. 2).

  According to the configuration and operation of the present embodiment, the second pressure reducing means is provided with the suction refrigerant throttle valve 52 having a fixed throttle, and the electromagnetic opening / closing provided in parallel with the suction refrigerant throttle valve 52 to switch between the open state and the closed state. It consists of a valve 53. The ECU 10 controls the discharge capacity of the compressor 21 so that the value of the evaporator temperature TE, which is a related physical quantity of the heat absorption capability of the evaporator 27, matches the target vapor temperature TEO, which is the target value of heat absorption, and the heating capability of the condenser 22 The solenoid on / off valve 53 is opened and closed so that the value of the condenser temperature TAV, which is a related physical quantity, coincides with the target blowing temperature TAO, which is a heating target value, and the refrigerant pressure reduction amount is controlled in two stages.

  Even in this manner, similarly to the first embodiment, even if the evaporator temperature TE is made to coincide with the target evaporator temperature TEO having restrictions for preventing frost of the evaporator 27, for example, the temperature TAV of the condenser 22 is equal to the air duct. 2, the refrigerant discharge capacity of the compressor 21, and the pressure reduction amount of the second pressure reducing means composed of the suction refrigerant throttle valve 52 and the electromagnetic on-off valve 53 so as to coincide with the target blowing temperature TAO that can sufficiently heat the air flowing in the air 2. Can be controlled.

  Therefore, it is the cycle refrigerant circulation flow rate determined by the restriction of the heat absorption capability of the evaporator 27, and even if the heat absorption capability of the outdoor heat exchanger 24 is maximized by fully opening the cooling variable throttle valve 26, the heating capability in the condenser 22 is insufficient. In this case, a cycle state as indicated by a solid line in the pressure-enthalpy diagram of FIG. 9 can be formed, and the same effect as in the first embodiment can be obtained.

  Further, the variable pressure reduction type second pressure reducing means can be simply configured by the suction refrigerant throttle valve 52 and the electromagnetic on-off valve 53 which are fixed throttle valves, and the pressure reduction amount variable control can be simplified.

  In the above-described example, the ECU 10 controls the discharge capacity of the compressor 21 so that the value of the evaporator temperature TE, which is a related physical quantity of the heat absorption capability of the evaporator 27, coincides with the target evaporator temperature TEO, which is the heat absorption target value. The refrigerant on-off valve 53 is opened and closed to control the refrigerant pressure reduction amount so that the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the vessel 22, coincides with the target blowing temperature TAO, which is the heating target value.

  On the other hand, the ECU 10 controls the discharge capacity of the compressor 21 so that the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the condenser 22, matches the target blowing temperature TAO, which is the heating target value, and the evaporator 27 The refrigerant pressure reduction amount may be controlled by opening and closing the electromagnetic on-off valve 53 so that the value of the evaporation temperature TE, which is a related physical quantity of the heat absorption capability, coincides with the target evaporation temperature TEO, which is the endothermic target value.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  Moreover, even if there is a restriction on the heat absorption capability of the evaporator described in the column of the problem to be solved by the invention, obtaining a sufficient external fluid heating capability in the radiator is described below with reference to the drawings. This embodiment is also possible.

  First, one embodiment will be described with reference to FIGS. FIG. 16 is a schematic diagram showing a schematic configuration of a vehicle air conditioner using the refrigeration cycle apparatus 3C.

  The vehicle air conditioner of this embodiment illustrated in FIG. 16 includes an air conditioning unit (air conditioner unit) 101 that air-conditions the interior of a vehicle such as an automobile, and the air conditioning unit 101 is disposed inside the interior of the automobile. A blower duct 2 (corresponding to a duct) that forms an air passage for guiding conditioned air, a centrifugal blower that generates an air flow toward the vehicle interior in the blower duct 2, and an evaporator that cools the air flowing in the blower duct 2 Refrigeration cycle 3C (corresponding to a refrigeration cycle apparatus) including a condenser 27 (corresponding to a radiator) that reheats the air that has passed through the evaporator 27 (corresponding to an evaporator, and may be referred to as an evaporator hereinafter) And.

  As shown in FIG. 16, the refrigeration cycle 3 </ b> C of the present embodiment is provided with a discharge refrigerant throttle valve 54 that depressurizes the refrigerant discharged from the compressor 21 and flowing into the condenser 27. The discharge refrigerant throttle valve 54 is a decompression device that depressurizes the refrigerant discharged from the compressor 21 according to the valve opening, and an electric expansion valve whose valve opening is electrically controlled by the ECU 10 is used. In addition, the discharge refrigerant throttle valve 54 can be set to a fully open mode in which the valve opening is fully opened under the control of the ECU 10. The discharge refrigerant throttle valve 54 is specifically provided in a refrigerant pipe that connects the refrigerant outlet of the compressor 21 and the refrigerant inlet of the condenser 22.

  And ECU10 which is a control means which controls each air-conditioning apparatus (an actuator etc.) in the air-conditioning unit 101 performs a control process according to the control flow shown in FIG. 2 similarly to 1st Embodiment mentioned above.

  In the present embodiment, when executing step 220 shown in FIG. 2, first, the evaporator temperature TE detected by the evaporator temperature sensor 45 coincides with the target evaporator temperature TEO calculated in step 180, as shown in FIG. Thus, the rotation control of the compressor 21 (that is, the control of the refrigerant discharge capacity) is performed (as much as possible) (step 221).

  If step 221 is executed, it is next determined whether or not the control flag of the discharged refrigerant throttle valve 54 is 1 (step 222c). The control flag of the discharge refrigerant throttle valve 54 is 1 so that the condenser temperature TAV obtained (calculated) based on the refrigerant pressure detected by the refrigerant pressure sensor 42 matches the target blowout temperature TAO (approximated as much as possible). In addition, the opening degree of the refrigerant flow through which the discharge refrigerant throttle valve 54 passes is controlled, and when the control flag of the discharge refrigerant throttle valve 54 is 0, the refrigerant flow through which the discharge refrigerant throttle valve 54 passes is not throttled. This setting is fixed at full open.

  When it is determined in step 222c that the control flag of the discharged refrigerant throttle valve 54 is not 1, that is, the control flag is 0, the condenser temperature TAV obtained based on the refrigerant pressure detected by the refrigerant pressure sensor 42 is the target. The opening adjustments of the heating variable throttle valve 23 and the cooling variable throttle valve 26 are performed so as to coincide with the blowout temperature TAO (as close as possible) (step 223).

  As a result of executing Step 223, whether or not the heating capacity of the condenser 22 is insufficient even when the cooling variable throttle valve 26 is opened to reach the fully opened state and the cooling variable throttle valve 26 is fully opened. Judgment is made (step 224). In Step 224, even if Step 223 is executed to control the condenser temperature TAV so as to coincide with the target blowing temperature TAO, the condenser temperature TAV cannot be raised to the target blowing temperature TAO, as shown in FIG. In addition, it is determined whether the heating capacity is insufficient.

  Even if the cooling variable throttle valve 26 is not fully opened in step 224, the heating capacity in the condenser 22 is not insufficient, or if the cooling variable throttle valve 26 is fully opened, the heating capacity in the condenser 22 is not insufficient. If it is determined, the process returns with the control flag of the discharged refrigerant throttle valve 54 set to 0 (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 224 that the heating capacity of the condenser 22 is insufficient even when the cooling variable throttle valve 26 is fully opened, that is, the outdoor heat exchanger 24 is replaced with an evaporator (heat absorber) having the same refrigerant pressure as the evaporator 27. ), The control flag of the discharge refrigerant throttle valve 54 is set to 1 (step 225c), and the process returns (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 222c that the control flag for the discharge refrigerant throttle valve 54 is 1, the discharge refrigerant throttle valve 54 is opened so that the condenser temperature TAV matches the target blowout temperature TAO (as close as possible). The degree is adjusted (step 226c).

  As a result of executing step 226c, it is determined whether or not the heating capacity in the condenser 22 is excessive even if the discharge refrigerant throttle valve 54 is opened and reaches the fully open state, and the discharge refrigerant throttle valve 54 is in the fully open state. (Step 227c). In step 227c, even if step 226c is executed to control the condenser temperature TAV so as to coincide with the target blowing temperature TAO, the condenser temperature TAV cannot be lowered to the target blowing temperature TAO, as shown in FIG. Determine if the heating capacity is excessive.

  In step 227c, the heating capacity in the condenser 22 is not excessive even if the discharge refrigerant throttle valve 54 is not fully opened, or the heating capacity in the condenser 22 is not excessive if the discharge refrigerant throttle valve 54 is fully opened. If it is determined, the process returns with the control flag of the discharge refrigerant throttle valve 54 being set to 1 (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 227c that the heating capacity of the condenser 22 is excessive even when the discharge refrigerant throttle valve 54 is fully opened, the control flag of the discharge refrigerant throttle valve 54 is set to 0 (step 228c) and the process returns ( Proceed to step 230 shown in FIG.

  According to the above-described configuration and operation, when the cooling operation in step 200 is set by the determination in step 190 in FIG. 2, the heating variable throttle valve 23 is in the fully open mode, the heating electromagnetic valve 34 is closed, and the cooling is performed. When the variable throttle valve 26 is set to a flow control opening degree that decompresses and expands the refrigerant (becomes the decompression and expansion mode), the refrigerant circulates as shown by a solid line in FIG. 17, and the operation mode of the refrigeration cycle 3C is the cooling operation mode. It becomes. In the cooling operation mode, the discharged refrigerant throttle valve 54 is in a fully open mode. Further, the air mix door 6 closes the air inlet portion of the condenser 22, and the condensation of the refrigerant in the condenser 22 is suppressed.

  Thereby, the air which distribute | circulates the inside of the ventilation duct 2 is cooled with the evaporator 27, and blows off into a vehicle interior. The amount of heat absorbed by the evaporator 27 and the amount of enthalpy increase due to the refrigerant adiabatic compression of the compressor 21 are radiated to the outside air by the outdoor heat exchanger 24.

  When the heating operation of step 210 is set by the determination of step 190, the heating variable throttle valve 23 becomes a flow control opening degree for decompressing and expanding the refrigerant (becomes a decompression expansion mode), and the heating electromagnetic valve 34 is opened, When the cooling variable throttle valve 26 is in the fully closed mode, the refrigerant circulates as shown by the solid line in FIG. 18, and the operation mode of the refrigeration cycle 3C becomes the heating operation mode. In the heating operation mode, the air mix door 6 opens the air inlet of the condenser 22, and air, which is an external fluid, is heated as the refrigerant condenses in the condenser 22.

  Thereby, the air which distribute | circulates the inside of the ventilation duct 2 is heated with the condenser 22, and blows off into a vehicle interior. The amount of heat radiated to the air by the condenser 22 is covered by the amount of heat absorbed from the outside air by the outdoor heat exchanger 24 and the amount of heat by the enthalpy increase due to the refrigerant adiabatic compression of the compressor 21.

When the dehumidifying heating operation of step 220 is set by the determination of step 190,
The heating variable throttle valve 23 has a flow control opening degree for decompressing and expanding the refrigerant (becomes a decompression and expansion mode), and the heating electromagnetic valve 34 is closed, whereby the refrigerant circulates as shown by a solid line in FIG. The operation mode of the cycle 3C is the dehumidifying heating operation mode. In the dehumidifying and heating operation mode, when the air heating capacity in the condenser 22 may be small, the cooling variable throttle valve 26 has a flow control opening degree for decompressing and expanding the refrigerant (becomes a decompression and expansion mode), and the discharge The refrigerant throttle valve 54 is in the fully open mode.

  On the other hand, when the air heating capacity in the condenser 22 is increased, the cooling variable throttle valve 26 is in a fully open mode, and the discharge refrigerant throttle valve 54 has a flow control opening degree for decompressing and expanding the refrigerant (decompressing expansion). Mode). In any case, the air mix door 6 opens the air inlet of the condenser 22. Thereby, the air dehumidified by the condensation and removal of the water vapor cooled and contained in the evaporator 27 is reheated with the condensation of the refrigerant in the condenser 22 and blown out into the vehicle interior.

  The amount of heat absorbed from the air flowing through the blower duct 2 in the evaporator 27 and the amount of enthalpy increase due to the refrigerant adiabatic compression of the compressor 21 (increased heat amount due to compression power) are air flowing through the blower duct 2 by the condenser 22. The heat is dissipated. The difference between the heat absorption amount in the evaporator 27 and the heat amount due to the increase in enthalpy by the compressor 21 and the heat release amount in the condenser 22 is compensated by the heat absorption amount or heat release amount in the outdoor heat exchanger 24.

  The refrigeration cycle 3 </ b> C of the present embodiment includes a variable pressure reduction type discharge refrigerant throttle valve 54 that depressurizes the refrigerant discharged from the compressor 21 and flowing into the condenser 22. When the heat absorption amount in the evaporator 27, the heat absorption amount in the outdoor heat exchanger 24, and the heat amount due to the increase in enthalpy by the compressor 21 are insufficient for the heat dissipation amount in the condenser 22, heat insulation is performed in the compressor 21. By increasing the amount of work to be compressed, the amount of heat of the enthalpy increase by the compressor 21 is increased, and the refrigerant discharged from the compressor 21 is decompressed by the discharge refrigerant throttle valve 54 and flows into the condenser 22. Thereby, the heat quantity which is insufficient for the heat radiation quantity in the condenser 22 can be secured.

  As described with reference to FIG. 20, the ECU 10 controls the discharge capacity of the compressor 21 so that the value of the evaporator temperature TE, which is a related physical quantity of the heat absorption capability of the evaporator 27, matches the target evaporator temperature TEO, which is the endothermic target value. Then, the amount of pressure reduction of the discharge refrigerant throttle valve 54 is controlled so that the value of the condenser temperature TAV that is a related physical quantity of the heating capacity of the condenser 22 coincides with the target blowing temperature TAO that is the heating target value.

  Thereby, even if the evaporator temperature TE is made to coincide with the target evaporator temperature TEO (for example, 1 ° C.) having restrictions for preventing frost of the evaporator 27, for example, the temperature TAV of the condenser 22 circulates in the air duct 2. The refrigerant discharge capacity of the compressor 21 and the pressure reduction amount of the discharge refrigerant throttle valve 54 can be controlled so as to coincide with the target blowing temperature TAO that can sufficiently heat the air.

  In other words, it is the cycle refrigerant circulation flow rate determined by the restriction of the heat absorption capacity of the evaporator 27, and even if the heat absorption capacity of the outdoor heat exchanger 24 is maximized by fully opening the cooling variable throttle valve 26, the heating capacity in the condenser 22 Is insufficient, a cycle state as shown by a solid line in the pressure-enthalpy diagram of FIG. 21 can be formed.

  Specifically, the work pressure of the compressor 21 is increased to increase the discharge pressure, and the increased discharge pressure is decompressed in an enthalpy manner by the discharge refrigerant throttle valve 54 to increase the enthalpy of the refrigerant flowing into the condenser 22. Can be made.

  The cycle indicated by the broken line in the pressure-enthalpy diagram of FIG. 21 is a comparative example in which the discharge refrigerant throttle valve 54 is not provided and the amount of work by the compressor 21 cannot be increased.

  According to the refrigeration cycle 3C of the present embodiment, even if the heat absorption capacity of the outdoor heat exchanger 24 is maximized, even when the heating capacity in the condenser 22 is insufficient, the work amount for compressing and discharging the refrigerant by the compressor 21 is reduced. The discharge pressure is increased to increase, and the increased refrigerant pressure is reduced by the discharge refrigerant throttle valve 54, whereby the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the condenser 22, is circulated in the air duct 2. The target blowing temperature TAO, which is a heating target value that can sufficiently heat the air to be performed, can be obtained. In this way, even if the heat absorption capability of the evaporator 27 is limited, a sufficient external fluid heating capability can be obtained in the condenser 22.

  In addition, both the adjustment of the discharge capacity of the compressor 21 that matches the evaporator temperature TE with the target evaporator temperature TEO and the adjustment of the pressure reduction amount of the discharge refrigerant throttle valve 54 that matches the condenser temperature TAV with the target outlet temperature TAO are controlled. This is performed by the ECU 10 as means. Therefore, it is easy to ensure the adjustment accuracy of the discharge capacity of the compressor 21 and the adjustment accuracy of the decompression amount of the discharge refrigerant throttle valve 54.

  Next, with respect to the above embodiment, the ECU 10 discharges the compressor 21 so that the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the condenser 22, matches the target blowing temperature TAO, which is the heating target value. For an embodiment in which the capacity is controlled and the pressure reduction amount of the discharge refrigerant throttle valve 54 is controlled so that the value of the evaporator temperature TE, which is a related physical quantity of the heat absorption capability of the evaporator 27, coincides with the target evaporator temperature TEO, which is the endothermic target value. This will be described with reference to FIG.

  As shown in FIG. 22, in the present embodiment, when executing step 220 shown in FIG. 2, first, the condenser temperature TAV obtained based on the refrigerant pressure detected by the refrigerant pressure sensor 42 is the target outlet temperature TAO. The rotation control of the compressor 21 (that is, the control of the refrigerant discharge capacity) is performed so as to match (as close as possible) (step 221a).

  If step 221a is executed, it is next determined whether or not the control flag of the discharged refrigerant throttle valve 54 is 1 (step 222c). When the control flag of the discharge refrigerant throttle valve 54 is 1, the discharge refrigerant throttle valve is set so that the evaporation temperature TE detected by the evaporation temperature sensor 45 matches the target evaporation temperature TEO calculated in step 180 (as close as possible). 54 is a setting in which the opening degree of the refrigerant flow rate through which the refrigerant passes is controlled to be controlled, and the control flag of the discharge refrigerant throttle valve 54 is set to be fully open and the refrigerant flow rate through which the discharge refrigerant throttle valve 54 passes is not throttled. .

  If it is determined in step 222c that the control flag of the discharged refrigerant throttle valve 54 is not 1, that is, the control flag is 0, the evaporator temperature TE detected by the evaporator temperature sensor 45 is the target evaporator temperature TEO calculated in step 180. (Step 223a) is performed to adjust the opening degree of the heating variable throttle valve 23 and the cooling variable throttle valve 26 so as to coincide with each other (as close as possible).

  As a result of executing step 223a, the dehumidifying capacity (heat absorption capacity) in the evaporator 27 is excessive even when the variable throttle valve for cooling 26 is opened to reach the fully opened state and the variable throttle valve for cooling 26 is fully opened. (Step 224a). In step 224a, even if step 223a is executed and control is performed so that the evaporation temperature TE coincides with the target evaporation temperature TEO, the evaporation temperature TE cannot be raised to the target evaporation temperature TEO, and as shown in FIG. Determine if the dehumidifying capacity is excessive.

  In step 224a, the dehumidifying capacity in the evaporator 27 does not become excessive even if the variable throttle valve 26 for cooling is not fully opened, or the dehumidifying capacity in the evaporator 27 is excessive if the variable throttle valve 26 for cooling is fully opened. If it is determined that the condition does not occur, the control is returned while the control flag of the discharged refrigerant throttle valve 54 is set to 0 (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 224a that the dehumidifying capacity of the evaporator 27 is excessive even when the cooling variable throttle valve 26 is fully opened, that is, the outdoor heat exchanger 24 is an evaporator having the same refrigerant pressure as that of the evaporator 27 ( If it is determined that the dehumidifying capacity of the evaporator 27 is excessive even if it functions as a heat absorber, the control flag of the discharge refrigerant throttle valve 54 is set to 1 (step 225c), and the process returns (step 230 shown in FIG. 2). Go to).

  If it is determined in step 222c that the control flag of the discharge refrigerant throttle valve 54 is 1, the opening degree of the discharge refrigerant throttle valve 54 is set so that the evaporation temperature TE matches the target evaporation temperature TEO (as close as possible). Adjustment is performed (step 226d).

  As a result of executing step 226d, it is determined whether or not the dehumidifying capacity in the evaporator 27 is insufficient even when the discharge refrigerant throttle valve 54 is opened and reaches the fully open state, and the discharge refrigerant throttle valve 54 is in the fully open state. (Step 227d). In step 227d, even if step 226d is executed to control the evaporation temperature TE so as to match the target evaporation temperature TEO, the evaporation temperature TE cannot be decreased to the target evaporation temperature TEO, and as shown in FIG. Determine if your ability is insufficient.

  In step 227d, it is determined that the dehumidifying capacity of the evaporator 27 is not insufficient even if the discharge refrigerant throttle valve 54 is not fully opened, or that the dehumidifying capacity of the evaporator 27 is not insufficient if the discharge refrigerant throttle valve 54 is fully opened. In this case, the process returns with the control flag of the discharged refrigerant throttle valve 54 set to 1 (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 227d that the dehumidifying capacity of the evaporator 27 is insufficient even when the discharge refrigerant throttle valve 54 is fully opened, the control flag of the discharge refrigerant throttle valve 54 is set to 0 (step 228c) and the process returns (FIG. 2). Go to step 230).

  According to the configuration and operation of the present embodiment, the ECU 10 discharges the compressor 21 so that the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the condenser 22, coincides with the target blowing temperature TAO that is the heating target value. The capacity is controlled, and the pressure reduction amount of the discharge refrigerant throttle valve 54 is controlled so that the value of the evaporator temperature TE, which is a related physical quantity of the heat absorption capability of the evaporator 27, coincides with the target evaporator temperature TEO which is the endothermic target value.

  Even in this manner, similarly to the above-described embodiment, even if the evaporator temperature TE is made to coincide with the target evaporator temperature TEO having restrictions for preventing the evaporator 27 from being frosted, for example, the temperature TAV of the condenser 22 is equal to the air duct 2. The refrigerant discharge capacity of the compressor 21 and the pressure reduction amount of the suction refrigerant throttle valve 50 can be controlled so as to coincide with the target blowing temperature TAO that can sufficiently heat the air flowing inside.

  This is the cycle refrigerant circulation flow rate determined by the restriction of the heat absorption capability of the evaporator 27, and even if the heat absorption capability of the outdoor heat exchanger 24 is maximized by fully opening the cooling variable throttle valve 26, the heating capability in the condenser 22 is insufficient. In this case, a cycle state as shown by a solid line in the pressure-enthalpy diagram of FIG. 21 can be formed, and the same effect as the above-described embodiment can be obtained.

  It can be said that the refrigeration cycle 3C of the two embodiments described here is a refrigeration cycle apparatus having the following characteristics.

A compressor (equivalent to the compressor 21) for sucking and compressing and discharging the refrigerant;
A radiator (equivalent to the condenser 22) that radiates the heat of the refrigerant discharged from the compressor and heats the external fluid;
First decompression means (corresponding to the heating variable throttle valve 23) for decompressing and expanding the refrigerant flowing out of the radiator;
An evaporator (equivalent to the evaporator 27) that evaporates the refrigerant decompressed by the first decompression means and absorbs heat from the external fluid;
A second depressurizing means of variable depressurization amount that depressurizes the refrigerant discharged from the compressor and flowing into the radiator (equivalent to the discharged refrigerant throttle valve 50),
One of the discharge capacity of the compressor and the pressure reduction amount of the second pressure reducing means is adjusted so that the heating capacity of the radiator or the related physical quantity value (corresponding to TAV) matches the heating target value (corresponding to TAO), and evaporation The other of the discharge capacity of the compressor and the pressure reduction amount of the second pressure reducing means is adjusted so that the heat absorption capacity of the compressor or the value of the related physical quantity (corresponding to TE) matches the endothermic target value (corresponding to TEO). This is a refrigeration cycle apparatus.

  If it has such characteristics, when the value of the endothermic capacity of the evaporator or the related physical quantity is matched with the limited endothermic target value, the heating capacity of the radiator or the value of the related physical quantity is The discharge capacity of the compressor and the pressure reduction amount of the second pressure reducing means can be adjusted so as to coincide with the heating target value that can sufficiently heat the external fluid. That is, even if the refrigerant circulation flow rate is determined by the restriction of the heat absorption capacity of the evaporator, the work pressure for compressing and discharging the refrigerant by the compressor is increased to increase the discharge pressure, and the increased refrigerant pressure is increased by the second pressure reducing means. By reducing the pressure enthalpy and allowing it to flow into the radiator, the enthalpy of the refrigerant flowing into the radiator can be reduced compared to when the discharge pressure is increased due to increased work in the compressor and when the increased discharge pressure is not reduced. Can be increased. Thereby, the heating capacity of the radiator or the value of the related physical quantity can be set to a heating target value that can sufficiently heat the external fluid. In this way, even if the heat absorption capability of the evaporator is limited, it is possible to obtain a sufficient external fluid heating capability in the radiator.

  Moreover, even if there is a restriction on the heat absorption capability of the evaporator described in the column of the problem to be solved by the invention, obtaining a sufficient external fluid heating capability in the radiator is described below with reference to the drawings. This embodiment is also possible.

  First, one embodiment will be described with reference to FIGS. FIG. 23 is a schematic diagram showing a schematic configuration of a vehicle air conditioner using the refrigeration cycle apparatus 3D.

  The vehicle air conditioner of this embodiment illustrated in FIG. 23 includes an air conditioning unit (air conditioner unit) 201 that air-conditions the interior of a vehicle such as an automobile, and the air conditioning unit 201 is disposed inside the interior of the automobile. A blower duct 2 (corresponding to a duct) that forms an air passage for guiding conditioned air, a centrifugal blower that generates an air flow toward the vehicle interior in the blower duct 2, and an evaporator that cools the air flowing in the blower duct 2 Refrigeration cycle 3D (corresponding to a refrigeration cycle apparatus) having a condenser 27 (corresponding to a radiator) that reheats the air that has passed through the evaporator 27 (corresponding to an evaporator, sometimes referred to as an evaporator) 27 And.

  As shown in FIG. 23, the refrigeration cycle 3D of the present embodiment is not provided with the aforementioned suction refrigerant throttle valve or discharge refrigerant throttle valve.

  The ECU 10, which is a control means for controlling each air conditioner (actuator or the like) in the air conditioning unit 201, performs control processing according to the control flow shown in FIG. 2 as in the first embodiment described above.

  In the present embodiment, when step 220 shown in FIG. 2 is executed, first, the evaporator temperature TE detected by the evaporator temperature sensor 45 coincides with the target evaporator temperature TEO calculated in step 180, as shown in FIG. Thus, the rotation control of the compressor 21 (that is, the control of the refrigerant discharge capacity) is performed (as much as possible) (step 221).

  After step 221 is executed, it is next determined whether or not the control flag of the heating variable throttle valve 23 is 1 (step 222e). The control flag of the heating variable throttle valve 23 is 1 (approximated as much as possible) so that the condenser temperature TAV obtained (calculated) based on the refrigerant pressure detected by the refrigerant pressure sensor 42 coincides with the target outlet temperature TAO. And so on, regardless of the cycle efficiency of the refrigeration cycle 3D, the opening is controlled to increase the refrigerant flow rate. When the control flag of the heating variable throttle valve 23 is 0, the cycle efficiency of the refrigeration cycle 3D is optimized. The opening degree is controlled so that

  When it is determined in step 222e that the control flag of the heating variable throttle valve 23 is not 1, that is, the control flag is 0, the condenser temperature TAV obtained based on the refrigerant pressure detected by the refrigerant pressure sensor 42 is The opening adjustments of the heating variable throttle valve 23 and the cooling variable throttle valve 26 are performed so as to coincide with the target blowing temperature TAO (as close as possible) (step 223).

  As a result of executing Step 223, the heating variable throttle valve 23 is throttled and the cooling variable throttle valve 26 is opened to reach the fully open state. The heating variable throttle valve 23 is set to the minimum opening and the cooling variable throttle valve 26 is opened. Whether or not the heating capacity in the condenser 22 is insufficient is determined even in a state where is fully opened (step 224e). In step 224e, even if step 223 is executed to maximize the heat absorption capacity of the outdoor heat exchanger 24 and the condenser temperature TAV is controlled to coincide with the target blowing temperature TAO, the condenser temperature TAV is set to the target blowing temperature TAO. As shown in FIG. 8, it is determined whether the heating capacity is insufficient.

  In step 224e, the heating capacity of the condenser 22 is not insufficient even if the heating variable throttle valve 23 is set to the minimum opening and the cooling variable throttle valve 26 is not fully opened, or the heating variable throttle valve 23 is minimized. If it is determined that the heating capacity of the condenser 22 is not insufficient if the cooling variable throttle valve 26 is fully opened, the routine returns with the control flag of the heating variable throttle valve 23 set to 0. (Proceed to step 230 shown in FIG. 2).

  If it is determined in step 224e that the heating variable throttle valve 23 has the minimum opening and the cooling variable throttle valve 26 is fully opened, the heating capacity of the condenser 22 is insufficient, that is, the outdoor heat exchanger 24 is evaporated. If it is determined that the heat capacity in the condenser 22 is insufficient even if the heat absorption capacity of the outdoor heat exchanger 24 is maximized by functioning as an evaporator (heat absorber) having the same refrigerant pressure as that of the condenser 27, the variable for heating is used. The control flag of the throttle valve 23 is set to 1 (step 225e), and the process returns (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 222e that the control flag of the heating variable throttle valve 23 is 1, the heating variable throttle valve 23 is set so that the condenser temperature TAV matches the target outlet temperature TAO (as close as possible). Is adjusted (step 226e). At this time, the cooling variable throttle valve 26 is fully opened.

  As a result of executing step 226e, the opening degree of the heating variable throttle valve 23 reaches the minimum state, and the heating variable throttle valve 23 is set to the minimum opening degree while the cooling variable throttle valve 26 is fully opened. Even so, it is determined whether or not the heating capacity in the condenser 22 is excessive (step 227e). In step 227e, even if step 226e is executed to control the condenser temperature TAV so as to coincide with the target blowing temperature TAO, the condenser temperature TAV cannot be lowered to the target blowing temperature TAO, as shown in FIG. Determine if the heating capacity is excessive.

  In step 227e, the heating capacity in the condenser 22 does not become excessive even if the heating variable throttle valve 23 is not set to the minimum opening, or the heating capacity in the condenser 22 is set if the heating variable throttle valve 23 is set to the minimum opening. Is determined to be excessive, the process returns with the control flag of the heating variable throttle valve 23 set to 1 (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 227e that the heating capacity of the condenser 22 is excessive even when the heating variable throttle valve 23 is in the minimum opening state, the control flag of the heating variable throttle valve 23 is set to 0 (step 228e). , Return (proceed to step 230 shown in FIG. 2).

  According to the above-described configuration and operation, when the cooling operation in step 200 is set by the determination in step 190 in FIG. 2, the heating variable throttle valve 23 is in the fully open mode, the heating electromagnetic valve 34 is closed, and the cooling is performed. When the variable throttle valve 26 is set to a flow rate control opening for decompressing and expanding the refrigerant (becomes a decompression and expansion mode), the refrigerant circulates as shown by a solid line in FIG. It becomes. In the cooling operation mode, the air mix door 6 closes the air inlet of the condenser 22 and the condensation of the refrigerant in the condenser 22 is suppressed.

  Thereby, the air which distribute | circulates the inside of the ventilation duct 2 is cooled with the evaporator 27, and blows off into a vehicle interior. The amount of heat absorbed by the evaporator 27 and the amount of enthalpy increase due to the refrigerant adiabatic compression of the compressor 21 are radiated to the outside air by the outdoor heat exchanger 24.

  When the heating operation of step 210 is set by the determination of step 190, the heating variable throttle valve 23 becomes a flow control opening degree for decompressing and expanding the refrigerant (becomes a decompression expansion mode), and the heating electromagnetic valve 34 is opened, When the cooling variable throttle valve 26 is in the fully closed mode, the refrigerant circulates as shown by the solid line in FIG. 25, and the operation mode of the refrigeration cycle 3D becomes the heating operation mode. In the heating operation mode, the air mix door 6 opens the air inlet of the condenser 22, and air, which is an external fluid, is heated as the refrigerant condenses in the condenser 22.

  Thereby, the air which distribute | circulates the inside of the ventilation duct 2 is heated with the condenser 22, and blows off into a vehicle interior. The amount of heat radiated to the air by the condenser 22 is covered by the amount of heat absorbed from the outside air by the outdoor heat exchanger 24 and the amount of heat by the enthalpy increase due to the refrigerant adiabatic compression of the compressor 21.

When the dehumidifying heating operation of step 220 is set by the determination of step 190,
The heating variable throttle valve 23 has a flow control opening degree for decompressing and expanding the refrigerant (becomes a decompression and expansion mode), and the heating electromagnetic valve 34 is closed, whereby the refrigerant circulates as shown by a solid line in FIG. The operation mode of the cycle 3D becomes the dehumidification heating operation mode. In the dehumidifying and heating operation mode, when the air heating capacity in the condenser 22 may be small, the cooling variable throttle valve 26 has a flow control opening degree for decompressing and expanding the refrigerant (becomes the decompression and expansion mode). .

  On the other hand, when the air heating capacity in the condenser 22 needs to be increased, the cooling variable throttle valve 26 is in the fully open mode. In any case, the air mix door 6 opens the air inlet of the condenser 22. Thereby, the air dehumidified by the condensation and removal of the water vapor cooled and contained in the evaporator 27 is reheated with the condensation of the refrigerant in the condenser 22 and blown out into the vehicle interior.

  The amount of heat absorbed from the air flowing through the blower duct 2 in the evaporator 27 and the amount of enthalpy increase due to the refrigerant adiabatic compression of the compressor 21 (increased heat amount due to compression power) are air flowing through the blower duct 2 by the condenser 22. The heat is dissipated. The difference between the heat absorption amount in the evaporator 27 and the heat amount due to the increase in enthalpy by the compressor 21 and the heat release amount in the condenser 22 is compensated by the heat absorption amount or heat release amount in the outdoor heat exchanger 24.

  In the refrigeration cycle 3D of the present embodiment, when the heat absorption amount in the evaporator 27, the heat absorption amount in the outdoor heat exchanger 24, and the heat amount due to the increase in enthalpy by the compressor 21 are insufficient for the heat dissipation amount in the condenser 22. In this case, the opening degree of the heating variable throttle valve 23 is increased regardless of the cycle efficiency while keeping the opening degree of the cooling variable throttle valve 26 at the maximum. With this control alone, the refrigerant evaporation pressure in the outdoor heat exchanger 24 and the evaporator 27 increases, but in this embodiment, the rotational speed (discharge) of the compressor 21 is maintained so as to maintain the heat absorption capability (dehumidification capability) in the evaporator 27. Capacity) is controlled. That is, an increase in the refrigerant evaporation pressure in the outdoor heat exchanger 24 and the evaporator 27 is suppressed by increasing the rotation speed of the compressor 21, and the refrigerant evaporation pressure can be adjusted to be constant.

  As a result, the rotation speed (rotation speed) of the compressor 21 is increased while the suction pressure (refrigerant evaporation pressure) of the compressor 21 is kept constant, so that the refrigerant circulation flow rate of the refrigeration cycle 3D can be increased. Therefore, as shown in FIG. 28, although the enthalpy at the outlet of the condenser 22 is increased by increasing the opening degree of the heating variable throttle valve 23 and the change in enthalpy in the condenser 22 is decreased, the condenser 22 is reduced. Since the heating capacity at is the product of the change in enthalpy and the refrigerant flow rate, by increasing the refrigerant flow rate by increasing the work amount of the compressor 21, it is possible to secure the amount of heat that is insufficient for the heat dissipation amount in the condenser 22. Can do.

  As described with reference to FIG. 27, the ECU 10 controls the discharge capacity of the compressor 21 so that the value of the evaporator temperature TE, which is a related physical quantity of the heat absorption capability of the evaporator 27, coincides with the target evaporator temperature TEO, which is the endothermic target value. Then, the amount of pressure reduction of the heating variable throttle valve 23 is controlled so that the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the condenser 22, coincides with the target blowing temperature TAO which is the heating target value.

  Thereby, even if the evaporator temperature TE is made to coincide with the target evaporator temperature TEO (for example, 1 ° C.) having restrictions for preventing frost of the evaporator 27, for example, the temperature TAV of the condenser 22 circulates in the air duct 2. The refrigerant discharge capacity of the compressor 21 and the pressure reduction amount of the heating throttle valve 23 can be controlled so as to coincide with the target blowing temperature TAO that can sufficiently heat the air.

  In other words, even if the cooling variable throttle valve 26 is fully opened and the heat absorption capacity of the outdoor heat exchanger 24 is maximized when the circulation refrigerant flow rate is determined by the restriction of the heat absorption capacity of the evaporator 27, When the heating capacity is insufficient, a cycle state as shown by a solid line in the pressure-enthalpy diagram of FIG. 28 is formed regardless of the cycle operation efficiency, and the refrigerant circulation flow rate is increased by increasing the work amount of the compressor 21. Can do.

  According to the refrigeration cycle 3D of the present embodiment, even if the heat absorption capacity of the outdoor heat exchanger 24 is maximized, the opening degree of the heating variable throttle valve 23 is increased even when the heating capacity of the condenser 22 is insufficient. In addition, by increasing the work flow for compressing and discharging the refrigerant by the compressor 21 and increasing the refrigerant circulation flow rate, the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the condenser 22, is circulated in the air duct 2. The target blowing temperature TAO, which is a heating target value that can sufficiently heat the air to be performed, can be obtained. In this way, even if the heat absorption capability of the evaporator 27 is limited, a sufficient external fluid heating capability can be obtained in the condenser 22.

  In addition, the adjustment of the discharge capacity of the compressor 21 that matches the evaporator temperature TE with the target evaporator temperature TEO, and the adjustment of the pressure reduction amount of the heating variable throttle valve 23 that matches the condenser temperature TAV with the target outlet temperature TAO, both. It is performed by ECU10 which is a control means. Therefore, it is easy to ensure the adjustment accuracy of the discharge capacity of the compressor 21 and the adjustment accuracy of the pressure reduction amount of the heating variable throttle valve 23.

  Next, with respect to the above embodiment, the ECU 10 discharges the compressor 21 so that the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the condenser 22, matches the target blowing temperature TAO, which is the heating target value. An embodiment in which the capacity is controlled and the amount of pressure reduction of the heating variable throttle valve 23 is controlled so that the value of the evaporator temperature TE, which is a related physical quantity of the heat absorption capability of the evaporator 27, coincides with the target evaporator temperature TEO, which is the heat absorption target value. This will be described with reference to FIG.

  As shown in FIG. 29, in the present embodiment, when step 220 shown in FIG. 2 is executed, first, the condenser temperature TAV obtained based on the refrigerant pressure detected by the refrigerant pressure sensor 42 is the target outlet temperature TAO. The rotation control of the compressor 21 (that is, the control of the refrigerant discharge capacity) is performed so as to match (as close as possible) (step 221a).

  After step 221a is executed, it is next determined whether or not the control flag of the heating variable throttle valve 23 is 1 (step 222e). When the control flag of the heating variable throttle valve 23 is 1, the refrigeration cycle 3D is set so that the evaporator temperature TE detected by the evaporator temperature sensor 45 matches the target evaporator temperature TEO calculated in step 180 (as close as possible). The opening is controlled so as to optimize the cycle efficiency of the refrigeration cycle 3D when the control flag of the heating variable throttle valve 23 is 0. It is a setting to be done.

  When it is determined in step 222e that the control flag of the heating variable throttle valve 23 is not 1, that is, the control flag is 0, the evaporator temperature TE detected by the evaporator temperature sensor 45 is calculated by the target evaporator temperature calculated in step 180. The opening adjustments of the heating variable throttle valve 23 and the cooling variable throttle valve 26 are adjusted so as to coincide with TEO (as close as possible) (step 223a).

  As a result of executing Step 223a, the heating variable throttle valve 23 is throttled and the cooling variable throttle valve 26 is opened to reach the fully open state. The heating variable throttle valve 23 is set to the minimum opening and the cooling variable throttle valve 26 is opened. It is determined whether or not the dehumidification capacity (heat absorption capacity) in the evaporator 27 is excessive even in a state in which is fully opened (step 224f). In step 224f, even if step 223a is executed and control is performed so that the evaporation temperature TE coincides with the target evaporation temperature TEO, the evaporation temperature TE cannot be increased to the target evaporation temperature TEO, and as shown in FIG. Determine if the dehumidifying capacity is excessive.

  In step 224f, the dehumidifying capacity of the evaporator 27 does not become excessive even if the heating variable throttle valve 23 is set to the minimum opening and the cooling variable throttle valve 26 is not fully opened, or the heating variable throttle valve 23 is turned on. When it is determined that the dehumidifying capacity in the evaporator 27 does not become excessive if the cooling opening is set to the minimum opening and the cooling variable throttle valve 26 is fully opened, the control flag of the heating variable throttle valve 23 is set to 0. Return (proceed to step 230 shown in FIG. 2).

  In step 224f, when it is determined that the dehumidifying capacity in the evaporator 27 is excessive even when the heating variable throttle valve 23 is set to the minimum opening and the cooling variable throttle valve 26 is fully opened, that is, the outdoor heat exchanger 24. Is functioned as an evaporator (heat absorber) having the same refrigerant pressure as that of the evaporator 27 to maximize the heat absorption capability of the outdoor heat exchanger 24, the dehumidification capability of the evaporator 27 is determined to be excessive. Then, the control flag of the heating variable throttle valve 23 is set to 1 (step 225e), and the process returns (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 222e that the control flag of the heating variable throttle valve 23 is 1, the heating variable throttle valve 23 is set so that the evaporation temperature TE coincides with the target evaporation temperature TEO (as close as possible). The opening degree is adjusted (step 226f). At this time, the cooling variable throttle valve 26 is fully opened.

  As a result of executing step 226f, the opening of the heating variable throttle valve 23 reaches the minimum state, and the heating variable throttle valve 23 is set to the minimum opening degree with the cooling variable throttle valve 26 fully opened. Even so, it is determined whether or not the dehumidifying capacity in the evaporator 27 is insufficient (step 227f). In step 227f, even if step 226f is executed to control the evaporation temperature TE so as to coincide with the target evaporation temperature TEO, the evaporation temperature TE cannot be lowered to the target evaporation temperature TEO. As shown in FIG. Determine if your ability is insufficient.

  In step 227f, the dehumidifying capacity of the evaporator 27 does not become insufficient even if the variable aperture valve 23 for heating is not set to the minimum opening, or the dehumidifying capacity of the evaporator 27 is increased if the variable opening valve 23 for heating is set to the minimum opening. If it is determined that there is no shortage, the routine returns with the control flag of the heating variable throttle valve 23 set to 1 (proceeds to step 230 shown in FIG. 2).

  If it is determined in step 227f that the dehumidifying capacity in the evaporator 27 is insufficient even when the heating variable throttle valve 23 is in the minimum opening state, the control flag of the heating variable throttle valve 23 is set to 0 (step 228e), and the return (Proceed to step 230 shown in FIG. 2).

  According to the configuration and operation of the present embodiment, the ECU 10 discharges the compressor 21 so that the value of the condenser temperature TAV, which is a related physical quantity of the heating capacity of the condenser 22, coincides with the target blowing temperature TAO that is the heating target value. The capacity is controlled, and the amount of pressure reduction of the heating variable throttle valve 23 is controlled so that the value of the evaporator temperature TE, which is a related physical quantity of the heat absorption capability of the evaporator 27, coincides with the target evaporator temperature TEO, which is the endothermic target value.

  Even in this manner, similarly to the above-described embodiment, even if the evaporator temperature TE is made to coincide with the target evaporator temperature TEO (for example, 1 ° C.) having restrictions for preventing frost of the evaporator 27, for example, the temperature of the condenser 22 The refrigerant discharge capacity of the compressor 21 and the pressure reduction amount of the heating throttle valve 23 can be controlled so that the TAV matches the target blowing temperature TAO that can sufficiently heat the air flowing through the blower duct 2.

  Even if the cooling variable throttle valve 26 is fully opened and the heat absorption capacity of the outdoor heat exchanger 24 is maximized when the cycle refrigerant circulation flow rate is determined by the restriction of the heat absorption capacity of the evaporator 27, the heating capacity in the condenser 22 is insufficient. In this case, a cycle state as shown by a solid line in the pressure-enthalpy diagram of FIG. 28 can be formed regardless of the cycle operation efficiency, and the refrigerant circulation flow rate can be increased by increasing the work amount of the compressor 21, The same effects as those of the embodiment described above can be obtained.

  Further, since it is not necessary to provide an intake refrigerant throttle valve that depressurizes the refrigerant sucked by the compressor 21 and a discharge refrigerant throttle valve that depressurizes the refrigerant discharged from the compressor 21, the configuration can be simplified.

  It can be said that the refrigeration cycle 3D of the two embodiments described here is a refrigeration cycle apparatus having the following characteristics.

A compressor (equivalent to the compressor 21) for sucking and compressing and discharging the refrigerant;
A radiator (equivalent to the condenser 22) that radiates the heat of the refrigerant discharged from the compressor and heats the external fluid;
Decompression means (corresponding to the heating variable throttle valve 23) for decompressing and expanding the refrigerant flowing out of the radiator;
An evaporator (equivalent to the evaporator 27) that evaporates the refrigerant decompressed by the decompression means and absorbs heat from the external fluid;
One of the discharge capacity of the compressor and the pressure reduction amount of the pressure reducing means is adjusted so that the heating capacity of the radiator or the value of the related physical quantity (corresponding to TAV) matches the target heating value (corresponding to TAO). It is characterized in that the other of the discharge capacity of the compressor and the pressure reduction amount of the pressure reducing means is adjusted so that the endothermic capacity or the value of the related physical quantity (corresponding to TE) matches the endothermic target value (corresponding to TEO). The refrigeration cycle apparatus.

  If it has such characteristics, when the value of the endothermic capacity of the evaporator or the related physical quantity is matched with the limited endothermic target value, the heating capacity of the radiator or the value of the related physical quantity is The discharge capacity of the compressor and the pressure reduction amount of the pressure reducing means can be adjusted so as to coincide with the heating target value that can sufficiently heat the external fluid. If the refrigerant circulation flow rate determined by the restrictions on the operating efficiency of the refrigeration cycle and the heat absorption capacity of the evaporator is insufficient, the amount of decompression by the decompression means is reduced and the amount of work for compressing and discharging the refrigerant by the compressor. By increasing the refrigerant circulation flow rate, the heating capacity of the radiator or the value of the related physical quantity can be set to a heating target value that can sufficiently heat the external fluid. In this way, even if the heat absorption capability of the evaporator is limited, it is possible to obtain a sufficient external fluid heating capability in the radiator.

  In each of the above-described embodiments (the above-described four forms in the above-described first to fourth embodiments and other embodiments), the condenser temperature TAV, which is the radiator temperature, is used as the heating target as the related physical quantity of the heating capability of the radiator. Although the target blowing temperature TAO was used as a value, it is not limited to this. Other related physical quantities of the heat capacity of the radiator and the corresponding heating target value may be used, or the heat capacity of the radiator (for example, product of enthalpy change amount and refrigerant flow rate) and the corresponding heating target value. Also good.

  Further, the evaporator temperature TE, which is the evaporator temperature, is used as the physical quantity related to the heat absorption capability of the evaporator, and the target evaporator temperature TEO is used as the endothermic target value. However, the present invention is not limited to this. Other related physical quantities of the endothermic capacity of the evaporator and the corresponding endothermic target value may be used, or the endothermic capacity of the evaporator (eg, product of enthalpy change amount and refrigerant flow rate) and the corresponding endothermic target value may be used. Also good.

  Moreover, in each said embodiment, although the heat radiator was the condenser 22, it is not limited to this. For example, the present invention of a so-called supercritical refrigeration cycle apparatus in which the refrigerant discharged from the compressor has a critical pressure or higher is applied, and the radiator may be a gas cooler.

  Moreover, in each said embodiment, although refrigeration cycle 3, 3A, 3B, 3C, 3D was provided with the outdoor heat exchanger 24 other than the condenser 22 and the evaporator 27, it does not have an outdoor heat exchanger. The present invention is effective when applied to a refrigeration cycle apparatus.

  Further, in each of the above embodiments, the evaporator 27 is disposed on the upstream side of the air flow of the condenser 22. That is, although the external fluid of the condenser 22 and the evaporator 27 is the same fluid (air), it is not limited to this. The external fluid may be another fluid, or the external fluid of the condenser 22 and the external fluid of the evaporator 27 may be different.

  Moreover, although each said embodiment demonstrated the case where refrigeration cycle 3, 3A, 3B, 3C, 3D was applied to the vehicle air conditioner, it is not limited to this. It may be a refrigeration cycle apparatus for an air conditioner other than for a vehicle, or may be a refrigeration cycle apparatus used other than an air conditioner.

2 Air duct (duct)
3, 3A, 3B, 3C, 3D Refrigeration cycle (refrigeration cycle equipment)
10 Air-conditioning control device (control means)
21 Compressor
22 Condenser (heat radiator)
23 Variable throttle valve for heating (first decompression means)
27 Evaporator
50 Suction refrigerant throttle valve (second decompression means)
51 Suction refrigerant throttle valve (constant pressure valve, second pressure reducing means)
52 Suction refrigerant throttle valve (fixed throttle valve, part of second decompression means)
53 Electromagnetic on-off valve (on-off valve, part of second decompression means)

Claims (5)

A compressor (21) for sucking and compressing and discharging the refrigerant;
A radiator (22) for radiating heat of the refrigerant discharged from the compressor (21) to heat an external fluid;
First decompression means (23) for decompressing and expanding the refrigerant flowing out of the radiator (22);
An evaporator (27) for evaporating the refrigerant decompressed by the first decompression means (23) and absorbing heat from an external fluid;
A second decompression means (50) capable of changing a decompression amount for decompressing the refrigerant evaporated by the evaporator (27) and sucked by the compressor (21),
The discharge capacity of the compressor (21) and the pressure reduction of the second pressure reducing means (50) so that the heating capacity of the radiator (22) or the value of the related physical quantity (TAV) matches the heating target value (TAO). Adjusting one of the amounts, and adjusting the other of the discharge capacity and the amount of pressure reduction so that the endothermic capacity of the evaporator (27) or the value of the associated physical quantity (TE) matches the endothermic target value (TEO). A refrigeration cycle apparatus characterized by. Control means (10) for controlling the discharge capacity of the compressor (21) based on the heating capacity or the value of its related physical quantity (TAV),
The second pressure reducing means (51) is a constant pressure valve (51) for preventing the refrigerant pressure in the evaporator (27) from becoming less than a predetermined pressure even when the suction refrigerant pressure of the compressor (21) is reduced. And
The control means (10) controls the discharge capacity so that the heating capacity or a value (TAV) of the related physical quantity matches the heating target value (TAO),
The said pressure reduction amount is adjusted by the said 2nd pressure reduction means (51) so that the value (TE) of the said heat absorption capability or its related physical quantity may correspond with the said endothermic target value (TEO). The refrigeration cycle apparatus described. Based on the heating capacity or the related physical quantity value (TAV) and the endothermic capacity or the related physical quantity value (TE), the control of the discharge capacity of the compressor (21) and the second decompression means (50 Control means (10) for controlling the pressure reduction amount of
The control means (10) controls one of the discharge capacity and the pressure reduction amount so that the heating capacity or a value (TAV) of the related physical quantity matches the heating target value (TAO), and the heat absorption capacity or 2. The refrigeration cycle apparatus according to claim 1, wherein the other one of the discharge capacity and the pressure reduction amount is controlled so that a value (TE) of the related physical quantity matches the endothermic target value (TEO). The second pressure reducing means (52, 53) includes a fixed throttle valve (52) having a fixed throttle, and an on-off valve (53) provided in parallel to the fixed throttle valve (52) for switching between an open state and a closed state. )
The said control means (10) controls the said pressure reduction amount by switching the open / close state of the said on-off valve (52), The refrigerating-cycle apparatus of Claim 3 characterized by the above-mentioned. The radiator (22) and the evaporator (27) are disposed in a duct (2) through which air blown into the room is circulated so that the evaporator (27) is on the upstream side of the air flow,
The refrigeration cycle according to any one of claims 1 to 4, wherein the evaporator (27) absorbs heat from the air to dehumidify, and the radiator (22) heats the air. apparatus.

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