JP2006078036A - Refrigeration cycle device for cooling and cold storage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain both ensuring of frost preventing function of a cooling evaporator and improvement in cooling performance in a refrigerator at the time of cooling and cold storage simultaneous operation. <P>SOLUTION: When the cooling evaporator temperature is a set temperature or lower in a case that the cooling and cold storage simultaneous operation is set, a cooling-side solenoid valve is closed while keeping a compressor in an operating state (S130, S160 and S170) to interrupt a refrigerant flow to the cooling evaporator, and the refrigerant is released to a passage of a cold storage evaporator. When the cooling evaporator temperature is higher than the set temperature, the cooling-side solenoid valve is opened while keeping the compressor in the operating state (S130, S140 and S150) to release the refrigerant to a passage of the cooling evaporator. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a refrigerating cycle apparatus for cooling and refrigerating having a cooling evaporator and a refrigerating evaporator connected in parallel.

  Conventionally, it has a cooling evaporator and a refrigeration evaporator connected in parallel, and the refrigerant temperature in the refrigeration evaporator is set to be lower than the refrigerant temperature in the cooling evaporator. A cycle device is known (see, for example, Patent Document 1).

  In this prior art, in a refrigeration cycle device for vehicle cooling and refrigeration, a temperature-operated expansion valve and a solenoid valve are provided upstream of the cooling evaporator, and the refrigeration evaporator is provided as a decompression means upstream of the refrigeration evaporator. A constant pressure expansion valve is provided that opens when the refrigerant pressure of the refrigerant drops below a predetermined pressure.

  The solenoid valve upstream of the cooling evaporator is opened and closed at predetermined time intervals by the timer output of the control device. When this solenoid valve is closed, the refrigerant flow in the cooling evaporator side passage is blocked, and the refrigeration side low pressure (refrigerant pressure in the refrigeration evaporator) rapidly decreases due to the refrigerant suction action of the compressor.

  As a result, when the refrigerant pressure of the refrigeration evaporator drops to a predetermined pressure, for example, 0.1 MPa, the constant pressure expansion valve that has been closed until now opens, so the refrigeration evaporator is depressurized with the constant pressure expansion valve. The cooled low-pressure refrigerant flows in, and the low-pressure refrigerant absorbs heat from the air in the refrigerator and evaporates to cool the inside of the refrigerator.

  Here, when the cycle circulation refrigerant is HFC-134a, the refrigerant evaporation temperature at a refrigerant pressure = 0.1 MPa is a low temperature of −10 ° C., so that can juice can be rapidly cooled in the refrigerator, The ice making function can be demonstrated. On the other hand, the refrigerant pressure on the cooling evaporator side (cooling side low pressure) varies depending on the cooling heat load, but is normally balanced in the range of about 0.2 MPa to 0.4 MPa.

By the way, under the low load condition of the cooling evaporator, a so-called frost phenomenon occurs in which the temperature of the cooling evaporator drops to 0 ° C. or less and the condensed water freezes, so the temperature of the air blown from the cooling evaporator is detected. A temperature sensor is provided, and when the temperature of the air blown from the cooling evaporator is lowered to a set temperature (for example, 3 ° C.) or lower, control is performed to stop the operation of the compressor of the refrigeration cycle based on the detection signal of the temperature sensor, The frost of the cooling evaporator is prevented.
JP 61-280353 A

  Therefore, if the compressor operation is stopped to prevent frosting of the cooling evaporator during simultaneous cooling and refrigeration, which simultaneously cools the passenger compartment and the refrigerator, the cooling action of the refrigeration evaporator also stops. As a result, cooling in the refrigerator is hindered.

  In addition, after stopping the operation of the compressor to prevent the frost of the cooling evaporator, the temperature of the air blown from the cooling evaporator rises and immediately after the compressor is restarted, the refrigeration is performed by the timer output of the controller. When the refrigerant is caused to flow to the evaporator side, the refrigerant does not flow to the cooling evaporator during this time, and the cooling action of the cooling evaporator is stopped.

  In other words, after the temperature of the air blown from the cooling evaporator drops below the set temperature and the compressor is stopped, the cooling evaporator is used until the refrigerant flow to the refrigeration evaporator is cut off by the timer output. The cooling action is stopped.

  As a result, the temperature rise of the cooling evaporator is increased and the temperature of the air blown out from the passenger compartment is also increased, so that the cooling feeling of the passenger is deteriorated.

  In view of the above points, an object of the present invention is to achieve both the securing of the frost prevention function of the cooling evaporator and the improvement of the cooling performance in the refrigerator during the simultaneous cooling and refrigeration operation.

  Another object of the present invention is to improve the cooling feeling during the simultaneous cooling and refrigeration operation.

In order to achieve the above object, in the invention according to claim 1, a cooling evaporator (20, 24),
A refrigeration evaporator (27) provided in parallel with the cooling evaporator (20, 24);
A compressor (10) that sucks and compresses the refrigerant that has passed through the cooling evaporator (20, 24) and the refrigeration evaporator (27);
A cooling decompression device (19, 23) that is provided upstream of the cooling evaporator (20, 24) and decompresses refrigerant flowing into the cooling evaporator (20, 24);
A refrigeration decompression device (26) that is provided upstream of the refrigeration evaporator (27) and depressurizes refrigerant flowing into the refrigeration evaporator (27);
A cooling-side electric control valve (18, 22) for intermittently flowing the refrigerant flow on the cooling evaporator (20, 24) side;
Temperature detecting means (42a) for detecting the temperature of the cooling evaporator (20, 24);
A control means (40) for controlling the intermittent operation of the compressor (10) and the opening and closing of the cooling side electric control valves (18, 22) when the detection signal of the temperature detection means (42a) is inputted;
When the cooling and refrigeration simultaneous operation is set and the detected temperature of the temperature detecting means (42a) falls below a set temperature, the control means (40) keeps the compressor (10) in an operating state, Closing the cooling-side electric control valves (18, 22) so that the refrigerant flows through the passage of the refrigeration evaporator (27);
When the cooling and refrigeration simultaneous operation is set, if the detected temperature of the temperature detecting means (42a) becomes higher than the set temperature, the control means (40) maintains the compressor (10) in an operating state. The cooling side refrigeration cycle apparatus is characterized in that the cooling-side electric control valves (18, 22) are opened to allow the refrigerant to flow through the passages of the cooling evaporators (20, 24).

  According to this, when the temperature of the cooling evaporator (20, 24) decreases below the set temperature during the cooling and refrigeration simultaneous operation, the cooling side electric control valve (18, 24) is maintained while the compressor (10) is maintained in the operating state. By closing the valve 22), the refrigerant flow to the cooling evaporators (20, 24) can be cut off and frosting of the cooling evaporators (20, 24) can be prevented.

  In addition, at this time, the refrigerant flows into the passage of the refrigeration evaporator (27) by closing the cooling side electric control valves (18, 22), so that the cooling performance in the refrigerator can be surely exhibited.

  That is, while performing the frost prevention of the cooling evaporators (20, 24), the cooling performance in the refrigerator can be exhibited at the same time.

  In addition, since the evaporator frost prevention control and the cooling performance in the refrigerator are performed while the compressor (10) is maintained in an operating state, intermittent shock (abnormal noise) due to the compressor operation can be avoided. The comfort of the indoor environment can be improved.

  Further, when the temperature detected by the temperature detecting means (42a) becomes higher than the set temperature, the cooling-side electric control valves (18, 22) are opened, and the refrigerant immediately enters the passage of the cooling evaporators (20, 24). Therefore, the phenomenon that the temperature rise of the cooling evaporator becomes excessively large as in the prior art does not occur, and the cooling feeling of the occupant can be improved.

According to a second aspect of the present invention, in the refrigerating cycle apparatus for cooling and refrigerating according to the first aspect, the control means (40) has an information value related to a cooling load of the cooling evaporator (20, 24). Entered,
When the control unit (40) determines that the cooling load is in a high load state of a predetermined level or more when the cooling and refrigeration simultaneous operation is set, the control unit (40) determines the compressor (10 ) Is maintained in the operating state, and the valve-opening state and the valve-closing state of the cooling-side electric control valve (18, 22) are alternately repeated, and the cooling-side electric control valve (18, 22) is opened. Refrigerant flows through the passage of the evaporator (20, 24), and the refrigerant flows through the passage of the refrigeration evaporator (27) by closing the cooling-side electric control valve (18, 22),
On the other hand, when the simultaneous cooling and refrigeration operation is set, if the control means (40) determines that the cooling load is in a low load state below a predetermined level, the temperature detected by the temperature detection means (42a) Control is performed to determine opening and closing of the cooling side electric control valve (18, 22) according to the height of the air conditioner.

  According to this, the cooling evaporator (20, 24) is forcibly repeated by alternately repeating the open state and the closed state of the cooling side electric control valves (18, 22) at the time of cooling high load in the simultaneous cooling and refrigeration operation. ) And a state where the refrigerant flows through the passage of the refrigeration evaporator (27) can be alternately set. Therefore, the cooling performance in the refrigerator can be surely exhibited at the same time that the cooling performance is exhibited even at the time of cooling high load.

  And, at the time of cooling low load, as in claim 1, the cooling evaporator (20, 24) is opened and closed by opening and closing the cooling side electric control valves (18, 22) according to the level of the cooling evaporator temperature. While performing frost prevention, the cooling performance in the refrigerator can be reliably exhibited.

According to a third aspect of the present invention, in the refrigeration cycle apparatus for cooling and refrigerating according to the first or second aspect, when the cooling single operation is set, the cooling means electric control valve (18) is controlled by the control means (40). , 22) while maintaining the valve open state, the operation of the compressor (10) is interrupted according to the detected temperature of the temperature detecting means (42a),
When the refrigeration single operation is set, the compressor (10) is intermittently operated while the cooling electric control valves (18, 22) are kept closed by the control means (40). It is characterized by.

  According to this, the frost prevention function of the cooling evaporators (20, 24) can be exhibited and the refrigeration can be performed by intermittently operating the compressor (10) according to the level of the cooling evaporator temperature during the single cooling operation. The required cooling performance in the refrigerator can be exhibited by intermittent operation of the compressor (10) during the single operation.

  That is, the cooling / cooling simultaneous operation mode, the cooling single operation mode, and the cooling single operation mode can all be executed satisfactorily.

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

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cycle diagram of a refrigeration cycle apparatus for cooling and refrigerating according to the present embodiment, and shows an example applied to a dual air conditioner type vehicle air conditioner. Here, the “dual air conditioner type” includes both a front seat side air conditioning unit 21 that air-conditions the front seat side area in the vehicle interior and a rear seat side air conditioning unit 25 that air-conditions the rear seat side area in the vehicle interior. Of the form.

  In FIG. 1, the compressor 10 has an electromagnetic clutch 11, and is driven to rotate by a vehicle engine (not shown) via the electromagnetic clutch 11. A condenser 12 is connected to the discharge side of the compressor 10 as a radiator for high-pressure refrigerant.

  The high-pressure gas refrigerant discharged from the compressor 10 dissipates heat to the outside air through the condenser 12 and condenses. A liquid receiver 13 is connected to the outlet side of the condenser 12, and the gas / liquid of the outlet refrigerant (condensed refrigerant) of the condenser 12 is separated in the liquid receiver 13.

  The excess liquid refrigerant is stored inside the liquid receiver 13 and the liquid refrigerant is led out downstream of the liquid receiver 13. The high-pressure liquid pipe 14 on the downstream side of the liquid receiver 13 is branched into three parallel passages. That is, a parallel passage of the front seat cooling side refrigerant passage 15, the refrigeration side refrigerant passage 16 and the rear seat cooling side refrigerant passage 17 is provided on the downstream side of the liquid receiver 13.

  The front-seat cooling-side refrigerant passage 15 includes an electromagnetic valve 18 that forms a front-seat-side electric control valve from the upstream side toward the downstream side, a temperature-actuated expansion valve 19 that forms a front-seat-side cooling pressure reducing device, A seat-side cooling evaporator 20 is provided in series.

  The solenoid valve 18 is a valve that opens when energized. As is well known, the temperature-actuated expansion valve 19 adjusts the valve element opening according to the degree of superheat of the outlet refrigerant of the cooling evaporator 20, thereby adjusting the refrigerant flow rate to the cooling evaporator 20. The degree of superheat of the outlet refrigerant of the cooling evaporator 20 is maintained at a predetermined value.

  The front seat side cooling evaporator 20 is disposed in the case 21 a of the front seat side air conditioning unit 21 described above. Air is blown into the case 21a by the front seat side electric blower 21b, and this blown air passes through the front seat side cooling evaporator 20 and is blown out to the front seat side region in the vehicle interior.

  The low-pressure refrigerant decompressed by the temperature-actuated expansion valve 19 flows into the cooling evaporator 20, and the low-pressure refrigerant absorbs heat from the blowing air in the front seat air conditioning unit 21 and evaporates to cool the blowing air. To do.

  A well-known inside / outside air switching box (not shown) is connected to the suction port 21c of the front seat side electric blower 21b, and the inside air (vehicle compartment air) or the outside air (vehicle compartment outside air) is supplied to the blower 21b through the inside / outside air switching box. Inhaled.

  The rear-seat cooling-side refrigerant passage 17 has the same configuration as the front-seat cooling-side refrigerant passage 15, and includes an electromagnetic valve 22 that forms a rear-seat-side electric control valve from the upstream side toward the downstream side, and a rear-seat-side cooling pressure reducing device. A temperature-actuated expansion valve 23 and a rear seat side cooling evaporator 24 are provided in series.

  The rear seat side cooling evaporator 24 is disposed in the case 25 a of the rear seat side air conditioning unit 25 described above. Air is blown into the case 25a by the rear seat side electric blower 25b, and the blown air passes through the rear seat side cooling evaporator 24 and the like and is blown out to the rear seat side region of the vehicle interior. The suction port 25c of the rear seat side electric blower 25b communicates with the rear seat side region of the vehicle interior, and the inside air on the rear seat side of the vehicle interior is sucked into the blower 25b.

  On the other hand, the refrigeration side refrigerant passage 16 is provided with a constant pressure expansion valve 26, a refrigeration evaporator 27, and a check valve 28, which form a refrigeration decompression device, in series from the upstream side to the downstream side.

  The refrigerator 27 for refrigeration is arrange | positioned in the heat insulation case 29a of the vehicle-mounted refrigerator 29 mounted in the appropriate place in a vehicle interior. The low-pressure refrigerant decompressed by the constant pressure expansion valve 26 absorbs heat from the air in the heat insulation case 29a and evaporates in the refrigeration evaporator 27, thereby cooling the internal space of the heat insulation case 29a.

  The check valve 28 allows the refrigerant to flow only in one direction from the outlet of the refrigeration evaporator 27 to the suction side of the compressor 10, and prevents the refrigerant from flowing in the opposite direction. Therefore, the check valve 28 can prevent the low-pressure refrigerant having a high temperature from flowing into the refrigerating evaporator 27 having a low refrigerant temperature (refrigerant pressure) from the outlet side of the cooling evaporators 20 and 24.

  The constant pressure expansion valve 26 is a pressure responsive valve that opens when its downstream pressure (refrigerant pressure in the refrigeration evaporator 27) drops below a predetermined valve opening pressure. Here, the valve opening pressure of the constant pressure expansion valve 26 is set to a value sufficiently lower than the refrigerant pressure (cooling side low pressure) on the cooling evaporators 20 and 24 side.

  Specifically, the refrigerant pressure on the cooling evaporators 20 and 24 side (cooling side low pressure) is normally in the range of about 0.2 MPa to 0.4 MPa, while the valve opening pressure of the constant pressure expansion valve 26 is For example, it is set to about 0.1 MPa. The refrigerant evaporation temperature at 0.1 MPa is −10 ° C. in the case of HFC-134a.

  The high pressure switch 30 is a pressure detection means for detecting a cycle high pressure, and is arranged in the high pressure liquid pipe 14 on the outlet side of the liquid receiver 13 in this example. A pressure switch 30 may be arranged. The high pressure switch 30 of this example is turned on when the high pressure rises to a predetermined upper limit value, for example, 3.1 MPa or more, and issues a compressor stop signal.

  Next, the outline of the electric control unit of this embodiment will be described with reference to FIG. 2. The air conditioning control device 40 is composed of a microcomputer and its peripheral circuits, etc., and performs predetermined arithmetic processing according to a program stored in the ROM. Control the operation of air conditioning equipment.

  On the output side of the air conditioning control device 40, the electromagnetic clutch 11, the electromagnetic valves 18, 22 of the compressor 10, the front seat side electric blower 21b, the rear seat side electric blower 25b, and the like are connected. Although not shown, actually, the actuator of the inside / outside air switching mechanism of the front seat side air conditioning unit 21, the actuator of the blowing temperature control mechanism, the blowing mode switching actuator, and the blowing temperature control mechanism of the rear seat side air conditioning unit 25 are illustrated. These actuators, the actuator of the blowing mode switching mechanism, and the like are also connected to the output side of the air conditioning control device 40, and the operations of these various air conditioning devices are controlled by the air conditioning control device 40. Therefore, the control means of the present invention is constituted by the air conditioning control device 40.

  On the other hand, the detection signal of the sensor group 41 and the operation signal of the air conditioning operation panel 43 are input to the input side of the air conditioning control device 40. The sensor group 41 includes the high pressure switch 30 described above, the blowout air temperature sensor 42a of the front seat side cooling evaporator 20, the outside air temperature sensor 42b, the inside air temperature sensor 42c, the solar radiation sensor 42d, the water temperature sensor 42e of the vehicle engine, and the like. The detection signals of these sensors are input to the air conditioning control device 40.

  The air conditioning operation panel 43 includes an air conditioner switch (cooling operation switch) 44 that outputs an operation command signal for the compressor 10 during cooling, a front seat air volume switching switch 45 that outputs an air volume switching signal for the front seat electric blower 21b, and a rear A rear seat air volume switching switch 46 for outputting an air volume switching signal for the seat side electric blower 25b, a temperature setting switch 47 for outputting a set temperature signal in the passenger compartment, a refrigerator switch 48 for outputting a refrigerator operation command signal, and the like are provided.

  Although not shown, the air conditioning operation panel 43 includes an inside / outside air switching switch that outputs an inside / outside air switching signal, a front seat side blowing mode switching switch that outputs a front seat side blowing mode switching signal, and a rear seat side blowing mode. A rear-seat side blowing mode changeover switch or the like that outputs a switching signal is provided, and various operation signals are input from the air conditioning operation panel 43 to the air conditioning control device 40.

  Next, the operation of this embodiment in the above configuration will be described. 3 and 4 are control flows executed by the microcomputer of the air-conditioning control device 40. The control flow starts in conjunction with the start of the vehicle engine. First, in step S10, the operation mode is determined.

  Specifically, when only the air conditioner switch 44 of the air conditioning operation panel 43 is turned on, it is determined that the cooling operation is independent, and when both the air conditioner switch 44 and the refrigerator switch 48 of the air conditioning operation panel 43 are turned on, the cooling operation is performed. It is determined that the refrigerating operation is simultaneous, and when only the refrigerator switch 48 is turned on, it is determined that the refrigerating operation is independent.

  When it is determined in step S10 that the cooling single operation is performed, the process proceeds to step S20, and the solenoid valves 18 and 22 are energized to open the solenoid valves 18 and 22. Next, in step S30, the evaporator temperature is determined based on the blown air temperature (detected temperature of the temperature sensor 42a) Te of the front seat side cooling evaporator 20.

  Specifically, as shown in FIG. 5, this determination is performed when the blown air temperature Te falls below a set temperature TEO (for example, 3 ° C.) for preventing frost, and the blown air temperature Te is set to the set temperature TEO + α. When it rises to (for example, 4 ° C.), it is determined to be ON.

  If ON determination is performed in step S30, it will progress to step S40 and will energize the electromagnetic clutch 11 of the compressor 10, and will make the electromagnetic clutch 11 into an ON (connection) state. Thereby, since the compressor 10 is rotationally driven by the vehicle engine, the refrigerant is discharged from the compressor 10 → the condenser 12 → the liquid receiver 13 → the front seat cooling side refrigerant passage 15 and the rear seat cooling side refrigerant in the refrigeration cycle. It circulates in a closed circuit from the parallel passage of the passage 17 to the suction side of the compressor 10.

  Therefore, by operating the front seat side electric blower 21b and the rear seat side electric blower 25b by the control output of the air conditioning control device 40, the blown air of each of the blowers 21b and 25b is changed to the front seat side cooling evaporator 20 and the rear seat. Cooled by the side-cooling evaporator 24 to become cool air, this cool air is blown out to the front seat side and rear seat side regions in the vehicle interior, and cools the front seat side and rear seat side regions in the vehicle interior. At this time, the refrigerant flow rate is adjusted by the temperature-actuated expansion valves 19 and 23 so that the degree of superheat of the outlet refrigerant of the cooling evaporators 20 and 24 becomes a predetermined value.

  Then, when the blown air temperature Te of the front seat side cooling evaporator 20 falls below a set temperature TEO (for example, 3 ° C.), the determination in step S30 is switched to OFF, so the process proceeds to step S50, and the electromagnetic clutch 11 is energized. The electromagnetic clutch 11 is turned off (disconnected) by being disconnected.

  As a result, the compressor 10 is stopped, so that the refrigerant circulation to the front seat side cooling evaporator 20 and the rear seat side cooling evaporator 24 is stopped, and the blown air temperature of the front seat side cooling evaporator 20 is stopped. Te begins to rise. Thereby, the frost of the front seat side cooling evaporator 20 and the rear seat side cooling evaporator 24 can be prevented.

  When the air temperature Te of the front seat side cooling evaporator 20 rises to TEO + α (for example, 4 ° C.) or more due to the stop of the compressor 10, the determination in step S30 is switched ON and the compressor 10 is activated again. To do.

  As described above, the blown air temperature Te of the front seat side cooling evaporator 20 is detected by the temperature sensor 42a, and the air conditioning control device 40 is set so that the blown air temperature is in the vicinity of the set temperature TEO (for example, 3 to 4 ° C.). The operation of the electromagnetic clutch 11 (compressor 10) is intermittently controlled by the control output.

  Thus, since the operation of the compressor 10 is intermittently controlled so that the blown air temperature of the front-seat-side cooling evaporator 20 is maintained in the vicinity of the set temperature TEO, the cycle low pressure is determined according to the variation in the cooling heat load. The balance is in the range of about 0.2 MPa to 0.4 MPa. Incidentally, when the cycle circulation refrigerant is HFC-134a, the cycle low pressure = 0.2 MPa corresponds to the refrigerant evaporation temperature 0 ° C., and the cycle low pressure = 0.4 MPa corresponds to the refrigerant evaporation temperature 15 ° C.

  On the other hand, the opening pressure of the constant pressure expansion valve 26 provided in the refrigeration side refrigerant passage 16 is the cycle low pressure during the cooling operation in order to obtain a low temperature for rapidly cooling the refrigerated product (can juice, etc.). Is set to a sufficiently low value, specifically 0.1 MPa.

  As a result, the cycle low pressure does not drop to the opening pressure of the constant pressure expansion valve 26 during the cooling only operation, and therefore the constant pressure expansion valve 26 remains closed. Therefore, the refrigerant does not flow into the refrigeration side refrigerant passage 16.

  Next, when the refrigerator switch 48 is also turned on in the state where the air conditioner switch 44 of the air conditioning operation panel 43 is turned on, the simultaneous cooling and refrigerating operation state is determined in step S10, and the process proceeds to the control flow of FIG.

  First, it is determined in step S60 whether the cooling load is high. The cooling load can be determined by various means. In this example, if the intake air temperature of the front-seat-side cooling evaporator 20 is equal to or higher than the set temperature, it is determined that the cooling load is high, and the front-seat-side cooling is used. If the intake air temperature of the evaporator 20 is lower than the set temperature, it is determined that the cooling load is low.

  Note that the intake air temperature of the front seat side cooling evaporator 20 does not require any special sensor to be set. In the inside air circulation mode, the detected temperature Tr of the inside air sensor 42c is set to the intake air temperature of the front seat side cooling evaporator 20. In the outside air introduction mode, the detected temperature Tam of the outside air sensor 42b may be used as the intake air temperature of the front seat side cooling evaporator 20.

  If it is determined in step S60 that the cooling load is high (high load), the process proceeds to step S70 to start an intermittent operation timer (hereinafter referred to as FIR timer). Here, as shown in FIG. 6 (a), the FIR timer outputs ON and OFF outputs for alternately repeating the opening and closing of the cooling side electromagnetic valves 18 and 22 at predetermined time intervals t1 and t2. It is.

  The time t1 in FIG. 6A is the opening time of the cooling side electromagnetic valves 18 and 22, and the time t2 is the closing time of the cooling side electromagnetic valves 18 and 22.

  In the next step S80, it is determined whether the FIR timer output is in the cooling side ON state (that is, the state of the solenoid valve opening command) at time t1 in FIG. While this determination is YES, the electromagnetic clutch 11 (compressor 10) is activated in step S90, and the cooling side electromagnetic valves 18 and 22 are opened in step S100.

  As a result, the refrigerant flows only through the cooling side electromagnetic valves 18 and 22 to the cooling side refrigerant passages 15 and 17, and the cooling evaporators 20 and 24 exhibit the cooling action in the vehicle compartment. When the cooling side electromagnetic valves 18 and 22 are opened, the cycle low pressure becomes a value of about 0.2 MPa to 0.4 MPa determined according to the cooling heat load, as in the above-described cooling single operation. For this reason, since the constant pressure expansion valve 26 is in the closed state, the refrigerant does not flow into the refrigeration side refrigerant passage 16.

  When the time t1 elapses and the FIR timer output becomes the cooling side OFF state (that is, the state of the solenoid valve closing command) at the time t2 in FIG. 6A, the determination in step S80 is switched to NO, so step S110 Thus, the electromagnetic clutch 11 (compressor 10) is activated, and the cooling side electromagnetic valves 18 and 22 are closed in step S120.

  When the cooling side electromagnetic valves 18 and 22 are closed, not only the refrigeration side refrigerant passage 16 but also the cooling side refrigerant passages 15 and 17 are cut off. As a result, a state occurs in which the high pressure side passage and the low pressure side passage of the refrigeration cycle are temporarily blocked.

  Therefore, the refrigerant in the low-pressure passage portions (evaporators 20, 24, and 27) of the cooling-side refrigerant passages 15 and 17 and the refrigeration-side refrigerant passage 16 passes through the compressor 10 to the cycle high-pressure side while the passage cutoff state is generated. The cycle low pressure will drop rapidly.

  When the cycle low pressure decreases to the valve opening pressure of the constant pressure expansion valve 26 after a predetermined time t0 (see FIG. 6B) elapses after the cooling side solenoid valves 18 and 22 are closed, the constant pressure expansion valve 26 is Since the valve is opened, the refrigerant flows through the refrigeration side refrigerant passage 16.

  Here, the valve opening pressure of the constant pressure expansion valve 26 is set to a low value of, for example, 0.1 MPa, and when the refrigerant is HFC-134a, the refrigerant evaporation temperature in the refrigeration evaporator 27 is −10 ° C. Since the temperature becomes low, refrigerated items such as can juices in the refrigerator 29 can be rapidly cooled and an ice making function can be exhibited.

  And when time t2 passes and the cooling side solenoid valves 18 and 22 return to the open state again, the cycle low pressure increases to a value of about 0.2 MPa to 0.4 MPa determined according to the cooling heat load. The constant pressure expansion valve 26 returns to the closed state again.

  At this time, the check valve 28 can prevent the refrigerant having a high temperature from flowing into the refrigeration evaporator 27 from the outlet side of the cooling evaporators 20 and 24. Thereby, the low temperature state in the refrigerator 29 can be maintained even after the cooling side electromagnetic valves 18 and 22 are opened and the cycle low pressure is increased.

  The opening time t1 of the cooling side electromagnetic valves 18 and 22 is, for example, about 60 seconds, and the closing time t2 is, for example, about 15 seconds. The allocation of the valve opening time and the valve closing time of the cooling side solenoid valves 18 and 22 takes into consideration the degree of increase in the passenger compartment temperature in the simultaneous cooling and refrigeration operation, the time required for the refrigerator temperature to fall to the target temperature, and the like. Determined.

  As described above, at the time of a high cooling load during the simultaneous cooling and refrigeration operation, the opening and closing of the cooling side electromagnetic valves 18 and 22 are alternately repeated at a predetermined time t1 and time t2 based on the output of the FIR timer. The vehicle compartment cooling operation 20 and 24 and the refrigerator 29 cooling operation by the refrigeration evaporator 27 can be executed intermittently.

  On the other hand, if it is determined in step S60 that the cooling load is low, the process proceeds to step S130, and the evaporator temperature is determined based on the blown air temperature (detected temperature of the temperature sensor 42a) Te of the front seat side cooling evaporator 20. Do. In this determination, as in step S30 described above, as shown in FIG. 5, the blown air temperature Te is compared with the set temperature TEO and the set temperature TEO + α to determine ON or OFF.

  While the blown air temperature Te is higher than the set temperature TEO (eg, 3 ° C.), the determination in step S130 is ON, the process proceeds to step S140, the electromagnetic clutch 11 (compressor 10) is activated, and the cooling side electromagnetic wave is activated in step S150. The valves 18 and 22 are opened. Thereby, a refrigerant | coolant flows into the evaporators 20 and 24 for cooling, and a vehicle interior cooling effect | action is performed.

  When the blown air temperature Te falls below the set temperature TEO, the determination in step S130 is turned off, the process proceeds to step S160, the electromagnetic clutch 11 (compressor 10) is activated, and the cooling side electromagnetic valves 18, 22 are closed in step S170. State.

  By closing the valve, the refrigerant flow to the front seat side and rear seat side cooling evaporators 20 and 24 is blocked, so that the front seat side and rear seat side cooling evaporators 20 and 24 can be prevented from being frosted. At the same time, by closing the cooling-side solenoid valves 18 and 22, the cycle low pressure is lowered as described above and the constant pressure expansion valve 26 is opened, so that the refrigerant flows into the refrigeration evaporator 27 and the inside of the refrigerator 29 Cooling action can be demonstrated.

  That is, when the evaporator blown air temperature Te is lower than the set temperature TEO at the time of cooling low load, the cooling side electromagnetic valves 18 and 22 are closed while the compressor 10 is in an operating state, thereby evaporating for cooling. The frost preventing action of the containers 20 and 24 and the cooling action in the refrigerator 29 can be exhibited simultaneously.

  Therefore, it is possible to avoid that the compressor 10 is stopped and the cooling operation in the refrigerator 29 is stopped to prevent the cooling evaporators 20 and 24 from being frosted.

  Then, if the evaporator blown air temperature Te rises to the set temperature TEO + α (for example, 4 ° C.) by closing the cooling side electromagnetic valves 18 and 22, the determination in step S130 is ON, and the cooling side electromagnetic valves 18 and 22 are turned on. Immediately returns to the valve open state. As a result, the vehicle compartment cooling operation of the cooling evaporators 20 and 24 is immediately restarted, so that the problem of excessively large temperature rises in the cooling evaporators 20 and 24 as in the prior art can be prevented.

  In addition, during the cooling and refrigeration simultaneous operation, the cooling evaporators 20 and 24 are prevented from being frosted while the compressor 10 is in an operating state at the time of cooling low load. The comfort of the passenger compartment environment can be improved.

  Next, when only the refrigerator switch 48 of the air-conditioning operation panel 43 is turned on, the refrigeration single operation is determined in step S10 of FIG. 3, and the process proceeds to step S180, and the cooling side electromagnetic valves 18 and 22 are closed. maintain.

  Then, in the next step S190, the FIR timer is started. This FIR timer is the same as the FIR timer described in step S70. In the next step S200, it is determined whether the FIR timer output is in the refrigeration side ON state at time t2 in FIG. While this determination is YES, in step S210, the electromagnetic clutch 11 (compressor 10) is put into an operating state.

  As a result, at the time of refrigeration single operation, the cycle low pressure decreases rapidly with the operation of the compressor 10 and the constant pressure expansion valve 26 opens, so that the refrigerant flows only in the refrigeration evaporator 27 and the inside of the refrigerator 29 Only exhibits cooling effect.

  On the other hand, when the FIR timer output is in the refrigeration side OFF state at time t1, the determination in step S200 is NO, the electromagnetic clutch 11 is disconnected in step S220, and the compressor 10 is stopped.

  Thus, the compressor 10 operates intermittently at predetermined time intervals in accordance with the FIR timer output during refrigeration single operation. Then, when the compressor 10 is intermittently operated, the refrigerant is allowed to flow only to the refrigeration evaporator 27 side, and the refrigerant pressure in the refrigeration evaporator 27 is lowered, so that the inside of the refrigerator can be satisfactorily cooled to a low temperature capable of making ice.

  The reason why the compressor 10 is intermittently operated during the refrigeration single operation is that the capacity of the in-vehicle refrigerator 29 is small and the required cooling capacity of the in-vehicle refrigerator 29 is significantly smaller than the required cooling capacity in the vehicle compartment. is there.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be variously modified as follows.

  (1) In the above-described embodiment, the cooling load of the front seat side cooling evaporator 20 is determined based on the intake air temperature of the front seat side cooling evaporator 20, but the front seat side cooling evaporator is Since the cooling load increases when the suction air volume of 20 increases, the accuracy of the cooling load determination can be improved by determining the cooling load in consideration of the suction air volume. The suction air volume can be determined by the rotation speed control signal of the electric blower 21b.

  (2) In an automatic control type air conditioner (automatic air conditioner) that automatically controls the interior temperature of the vehicle, the necessary blown air temperature TAO for maintaining the interior temperature at the set temperature is calculated. There is a correlation that the blown air temperature TAO decreases as the cooling load increases. Therefore, the cooling load may be determined based on the necessary blown air temperature TAO.

  Further, since there is a correlation that the blowing air temperature Te of the front-seat-side cooling evaporator 20 decreases as the cooling load decreases, the level of the cooling load may be determined based on the evaporator blowing air temperature Te. However, the temperature for determining whether the cooling load is high or low is a temperature (for example, about 10 ° C.) sufficiently higher than the set temperature TEO (for example, about 3 ° C.) for preventing frost in FIG. Further, as the elapsed time after the cooling start becomes longer, the passenger compartment temperature decreases and the cooling load decreases, so the level of the cooling load may be determined based on the elapsed time after the cooling start.

  (3) In the above-described embodiment, the dual air conditioner type refrigeration cycle apparatus in which the front seat side cooling evaporator 20 and the rear seat side cooling evaporator 24 are provided in parallel as the cooling evaporator has been described. The present invention can be similarly applied to a single air-conditioner type refrigeration cycle apparatus in which only one cooling evaporator is provided.

  (4) In the above-described embodiment, the temperature of the blown air from the front seat side cooling evaporator 20 is detected by the temperature sensor 42a, and the frost prevention control of the front seat side cooling evaporator 20 is performed. Instead of the evaporator blowing air temperature, the evaporator fin frost prevention control may be performed by detecting the evaporator fin surface temperature, the evaporator refrigerant tube surface temperature, and the like.

  (5) In the above-described embodiment, the valve opening time t1 and the valve closing time t2 of the cooling side electromagnetic valves 18 and 22 shown in FIG. 6A are set to predetermined times by the timer function during the simultaneous cooling and refrigerating operation. However, for example, when the temperature in the refrigerator is detected by a temperature sensor and the temperature in the refrigerator rises to the first predetermined temperature, the cooling-side electromagnetic valves 18 and 22 are closed, and the refrigerant is supplied to the refrigeration evaporator 27. When the temperature in the refrigerator decreases to a second predetermined temperature lower than the first predetermined temperature, the cooling-side electromagnetic valves 18 and 22 may be returned from the closed state to the open state.

  That is, instead of the timer function, the opening and closing of the cooling side electromagnetic valves 18 and 22 may be switched alternately in response to a change in the cooling state in the refrigerator.

  Similarly, the intermittent operation of the compressor 10 during the refrigeration single operation may be set in response to a change in the cooling state in the refrigerator instead of the timer function.

  (6) In the above-described embodiment, the temperature-actuated expansion valves 19 and 23 are used as the cooling pressure reducing device. However, instead of the temperature-actuated expansion valves 19 and 23, a fixed throttle such as a capillary tube or an orifice is used. May be.

  (7) In the above-described embodiment, the constant pressure expansion valve 26 that opens when the downstream side pressure falls below a predetermined valve opening pressure is provided as a pressure reducing device on the refrigeration side. An electric control valve that opens and closes in response to a detection signal from the pressure detecting means for detecting the downstream pressure is provided, and the electric control valve is configured to open when the downstream pressure drops below a predetermined valve opening pressure. May be.

  (8) In the above-described embodiment, the vehicle cooling / refrigeration refrigeration cycle apparatus has been described. However, the present invention can be similarly applied to a cooling / refrigeration refrigeration cycle apparatus for uses other than vehicles.

It is a refrigerating cycle figure showing one embodiment of the present invention. It is a block diagram of the electric control part in one Embodiment of this invention. It is a control flowchart in one embodiment of the present invention. It is a control flowchart in one embodiment of the present invention. It is explanatory drawing of evaporator temperature determination in one Embodiment of this invention. It is operation | movement explanatory drawing of the cooling side solenoid valve and refrigeration side constant pressure expansion valve in one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Compressor, 15, 17 ... Cooling side refrigerant passage, 16 ... Refrigeration side refrigerant passage,
18, 22 ... Solenoid valve (electric control valve), 19, 23 ... Temperature operated expansion valve (cooling decompression device), 20, 24 ... Cooling evaporator, 26 ... Constant pressure expansion valve (refrigeration decompression device), 27 ... Evaporator for refrigeration,
40 ... Air-conditioning control device (control means), 42a ... Temperature sensor (temperature detection means).

Claims (3)

Cooling evaporators (20, 24);
A refrigeration evaporator (27) provided in parallel with the cooling evaporator (20, 24);
A compressor (10) that sucks and compresses the refrigerant that has passed through the cooling evaporator (20, 24) and the refrigeration evaporator (27);
A cooling decompression device (19, 23) that is provided upstream of the cooling evaporator (20, 24) and decompresses refrigerant flowing into the cooling evaporator (20, 24);
A refrigeration decompression device (26) that is provided upstream of the refrigeration evaporator (27) and depressurizes refrigerant flowing into the refrigeration evaporator (27);
A cooling-side electric control valve (18, 22) for intermittently flowing the refrigerant flow on the cooling evaporator (20, 24) side;
Temperature detecting means (42a) for detecting the temperature of the cooling evaporator (20, 24);
A control means (40) for controlling the intermittent operation of the compressor (10) and the opening and closing of the cooling side electric control valves (18, 22) when the detection signal of the temperature detection means (42a) is inputted;
When the cooling and refrigeration simultaneous operation is set and the detected temperature of the temperature detecting means (42a) falls below a set temperature, the control means (40) keeps the compressor (10) in an operating state, Closing the cooling-side electric control valves (18, 22) so that the refrigerant flows through the passage of the refrigeration evaporator (27);
When the cooling and refrigeration simultaneous operation is set, if the detected temperature of the temperature detecting means (42a) becomes higher than the set temperature, the control means (40) maintains the compressor (10) in an operating state. The cooling side refrigeration cycle apparatus is characterized in that the cooling side electric control valves (18, 22) are opened and the refrigerant flows through the passages of the cooling evaporators (20, 24). An information value related to the cooling load of the cooling evaporator (20, 24) is input to the control means (40),
When the control unit (40) determines that the cooling load is in a high load state of a predetermined level or more when the cooling and refrigeration simultaneous operation is set, the control unit (40) determines the compressor (10 ) Is maintained in the operating state, and the valve-opening state and the valve-closing state of the cooling-side electric control valve (18, 22) are alternately repeated, and the cooling-side electric control valve (18, 22) is opened. Refrigerant flows through the passage of the evaporator (20, 24), and the refrigerant flows through the passage of the refrigeration evaporator (27) by closing the cooling-side electric control valve (18, 22),
On the other hand, when the simultaneous cooling and refrigeration operation is set, if the control means (40) determines that the cooling load is in a low load state below a predetermined level, the temperature detected by the temperature detection means (42a) 2. The refrigeration cycle apparatus for cooling and refrigerating according to claim 1, wherein control for determining opening and closing of the cooling-side electric control valve (18, 22) is performed in accordance with a height of the cooling. When the cooling only operation is set, the detected temperature of the temperature detecting means (42a) is increased or decreased while the cooling-side electric control valves (18, 22) are kept open by the control means (40). In response, the operation of the compressor (10) is interrupted,
When the refrigeration single operation is set, the compressor (10) is intermittently operated while the cooling electric control valves (18, 22) are kept closed by the control means (40). The refrigeration cycle apparatus for cooling and refrigerating according to claim 1 or 2.

Images