JP2006007866A - Vehicular air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily arrange without having a plurality of cold storage agents; and to store cold heat. <P>SOLUTION: In the vehicular air conditioner 10, a refrigerant is circulated through a first loop 20 connecting a compressor 12, a capacitor 14, an expansion valve 16 and an evaporator 18 by operation of the compressor 12, and thereby refrigerating cycle is performed. At this time, a liquid refrigerant is circulated in a second loop 28 by operation of a water pump 30, the liquid refrigerant performs heat exchange with the refrigerant of the first loop 20 in the evaporator 18, refrigerating cycle is carried out in the first loop 20, and the liquid refrigerant itself is cooled and the cold heat is stored. The cold heat is used, for example, for maintaining cooling in eco-run. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle air conditioner applied to a vehicle such as an automobile.

  As an air conditioner for a vehicle such as an automobile, there is known an apparatus for storing cold energy in a regenerator using a heat exchanger independent of a refrigeration cycle in order to reduce an air conditioning heat load (for example, Patent Document 1, Patent) Reference 2). In the thing of patent document 1, cold storage is performed using the air blower air downstream of an evaporator, and in the thing of patent document 2, cold storage is performed using the exhausted air which completed indoor air conditioning. Yes.

  Thus, the conventional vehicle air conditioner requires a large number of cold storage agents (containers) that store or release cold heat by changing the phase between the solid phase and the liquid phase. In addition, in order to store cold in the regenerator, it is necessary to provide a heat exchanger that is not used for indoor cooling. In particular, since this heat exchanger uses air as a heat medium, it is difficult to improve efficiency.

Further, as vehicles such as automobiles, so-called eco-run vehicles that have a function of automatically stopping the engine when the vehicle is stopped by waiting for a signal, for example, have been put into practical use in order to improve fuel consumption and reduce the amount of exhaust gas. In such an eco-run air conditioner, since the engine-driven compressor stops while the engine is stopped (during the eco-run period), the cooling is not maintained and the comfort in the passenger compartment cannot be maintained. There was a problem. In view of this, a technique has been considered in which air conditioning is maintained using cold energy stored in the regenerator while the engine, that is, the compressor is stopped. However, even in such a technique, a large number of cold storage agents are required as in the above case.
JP-A-6-156062 JP 2000-62450 A

  In view of the above facts, an object of the present invention is to provide a vehicle air conditioner that can be easily configured without a large number of cold storage agents and can store cold heat.

  In order to achieve the above object, a vehicle air conditioner according to a first aspect of the present invention is a vehicle air conditioner that performs a refrigeration cycle by circulating a refrigerant in a compressor, a condenser, a pressure reducing means, and an evaporator. The evaporator includes a circulation path for circulating a liquid refrigerant that exchanges heat with the refrigerant that performs the refrigeration cycle, and a liquid feeding device.

  In the vehicle air conditioner according to the first aspect, when the compressor is operated, the refrigerant circulates in the order of the compressor, the condenser, the decompression means, the evaporator, and the compressor to perform the refrigeration cycle. At this time, the liquid feeding device is activated to circulate the liquid refrigerant in the circulation path, and in the evaporator, the liquid refrigerant and at least a part of the refrigerant that performs the refrigeration cycle exchange heat. Thus, in the evaporator, the refrigerant that performs the refrigeration cycle evaporates (the refrigeration cycle is performed), and the liquid refrigerant that circulates in the circulation path is cooled. That is, cold heat is stored in the liquid refrigerant in the circulation path which is a closed space.

  Thereby, for example, this cooling heat (liquid refrigerant) can be circulated and used for cooling the blown air when the compressor is stopped or when the cooling load is large, and the air conditioning heat load can be reduced. In addition, since this vehicle air conditioner stores cold heat in the liquid refrigerant circulating in the evaporator, there is no need to provide a cold storage agent or a heat exchanger for storing cold heat through the air as in the prior art. Is simple. From another viewpoint, the evaporator and the regenerator (the regenerator of the circulating liquid refrigerant) are realized by one heat exchanger.

  Thus, in the vehicle air conditioner according to the first aspect, the vehicle air conditioner can be easily configured without a large number of cold storage agents, and can store cold heat.

  A vehicle air conditioner according to a second aspect of the present invention is the vehicle air conditioner according to the first aspect, wherein an indoor heat exchanger for exchanging heat between the liquid refrigerant and air blower air is provided in the circulation path. It was.

  In the vehicle air conditioner according to claim 2, the indoor heat exchanger provided in the circulation path through which the liquid refrigerant circulates performs heat exchange between the liquid refrigerant and the air blower air blown into the vehicle interior. The blown air is cooled. Thereby, for example, the interior of the vehicle is cooled from two locations by the evaporator and the indoor heat exchanger, or the evaporator is dedicated to the liquid refrigerant and the refrigerant that performs the refrigeration cycle (does not bear cooling of the air-conditioner blowout air). As a heat exchanger, it is possible to improve the heat exchange efficiency in the evaporator (the heat exchanger that is also a regenerator as described above).

  A vehicle air conditioner according to a third aspect of the present invention is the vehicle air conditioner according to the second aspect, wherein the liquid feeding device is operated by a control device when a cooling request is made when the compressor is stopped. It is an electric pump.

  In the vehicle air conditioner according to claim 3, for example, during a so-called eco-run period in which the engine is stopped during a boarding period such as waiting for a signal, the control device operates an electric pump which is a liquid feeding device, and the evaporator and the indoor heat Circulate liquid refrigerant with the exchanger. Thereby, for example, even when the compressor is driven by the engine and is stopped when the engine is stopped, the cooling (cooling of the blown air) is maintained for a certain period of time by the cold heat stored in the liquid refrigerant. Therefore, it is possible to improve the fuel consumption and reduce the amount of exhaust gas by performing the eco-run operation without sacrificing comfort.

  As described above, the vehicle air conditioner according to the present invention has an excellent effect that it can be easily configured without a large number of cold storage agents and can store cold heat.

  A vehicle air conditioner 10 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a block diagram showing a schematic overall configuration of a vehicle air conditioner 10 applied to an automobile. As shown in this figure, a vehicular air conditioner 10 includes a compressor 12 as a compressor, a condenser 14 as a condenser, an expansion valve 16 as a decompression means, and an evaporator 18 as an evaporator. The first loop 20 communicates with the refrigerant, and the refrigerant is circulated to perform a refrigeration cycle.

  The compressor 12 is coupled to an automobile engine 26 via an electromagnetic clutch 22 and a drive belt 24. As a result, the compressor 12 operates when the engine 26 is rotating and the electromagnetic clutch 22 is in the engaged state. The compressor 12 compresses a low-pressure gas-phase refrigerant into a high-temperature and high-pressure superheated gas-phase refrigerant. The electromagnetic clutch 22 is controlled to be intermittently controlled by an air conditioner ECU 52, which will be described later, thereby adjusting the refrigerant circulation amount by the compressor 12, that is, the cooling capacity. Instead of the compressor 12 in which the electromagnetic clutch 22 is intermittently controlled, a variable displacement compressor 12 may be employed.

  The condenser 14 is a heat exchanger between the refrigerant and the outside air disposed downstream of the compressor 12, and cools and condenses the superheated gas-phase refrigerant discharged from the compressor 12 to form a liquid-phase refrigerant. . The liquid-phase refrigerant that has flowed out of the condenser 14 is decompressed by the expansion valve 16 to become a low-pressure liquid phase.

  The evaporator 18 is a heat exchanger that evaporates the low-pressure liquid refrigerant into a low-pressure gas-phase refrigerant. In the present embodiment, the evaporator 18 is a heat exchanger of a refrigerant and a liquid refrigerant that performs the above-described refrigeration cycle, and its outer shell has a heat insulating structure. As the liquid refrigerant, for example, a long life coolant (LLC, antifreeze liquid) that is usually used as engine cooling water is used.

  The vehicle air conditioner 10 includes a second loop 28 that circulates the liquid refrigerant in the evaporator 18. The second loop 28 is a circulation path independent of the first loop 20, and a water pump 30 as a liquid feeding device is disposed on the path. By the operation of the water pump 30, the liquid refrigerant circulates through the second loop 28 to exchange heat with the refrigerant in the first loop 20, and the refrigerant is evaporated to form a low-pressure gas-phase refrigerant. On the other hand, the liquid refrigerant in the second loop 28 is cooled by the evaporation of the refrigerant in the first loop 20 and accumulates cold in the second loop 28 that is a closed space.

  Further, the vehicle air conditioner 10 includes an indoor heat exchanger 32 disposed on the second loop 28. The indoor heat exchanger 32 is a heat exchanger of liquid refrigerant and air that circulates in the second loop 28, and is disposed in an air conditioning case (air conditioning duct) 34 that communicates between the outside and the interior of the vehicle interior. It is designed to cool. Further, the evaporator 18 is disposed outside the air conditioning case 34.

  As shown in FIG. 2, the air conditioning case 34 is open at both ends, and an open air inlet 38 and an internal air intake 40 that are switched by the switching damper 36 are formed at one open end. A plurality of air outlets 44 are formed at the other opening end of the air conditioning case 34 so as to open toward the vehicle interior and to be appropriately opened and closed by the mode switching damper 42. In the present embodiment, the air outlet 44 includes a defroster outlet 44A, a side and center register outlet 44B, and a foot outlet 44C. Air that has been temperature-controlled by the mode switching damper 42 is provided at a desired position. It is the structure which can be blown out into the vehicle interior.

  In addition, an air-conditioning blower 46 is provided between the indoor heat exchanger 32, the outside air inlet 38, and the inside air inlet 40 in the air conditioning case 34. The air-conditioning blower 46 is configured to draw air into the air-conditioning case 34 from the outside air inlet 38 or the inside air inlet 40 by operating, and further send this air toward the indoor heat exchanger 32. An air mix damper 48 and a heater core 50 are provided on the downstream side of the indoor heat exchanger 32 in the air conditioning case 34. The air on the rear side of the indoor heat exchanger 32 is guided and heated to the heater core 50 according to the opening degree of the air mix damper 48, for example, and further mixed with air that is not heated by the heater core 50. It is sent to 44.

  The 2nd loop 28 demonstrated above is made into the heat insulation structure in which the piping part except the indoor heat exchanger 32 and the water pump 30 prevent the temperature rise of a liquid refrigerant.

  The vehicle air conditioner 10 includes an air conditioner ECU 52 as a control device in the present invention. The air-conditioner ECU 52 is configured to perform normal air-conditioner control such as control of the air-conditioning blower 46, the air mix damper 48, etc., and on / off (disconnection / coupling) control of the electromagnetic clutch 22, and is configured as follows. . The air conditioner ECU 52 is electrically connected to the water pump 30 and outputs a control signal for controlling the operation / stop of the water pump 30.

  The air conditioner ECU 52 is electrically connected to a temperature sensor 54 that outputs a signal corresponding to a blown air temperature (hereinafter referred to as blown air temperature) Te behind the indoor heat exchanger 32 in the air conditioning case 34 (hereinafter referred to as a blown air temperature). ing. Further, in the present embodiment, the air conditioner ECU 52 is electrically connected to an engine ECU 56 that controls the engine 26. The engine ECU 56 stops the operation of the engine 26 and starts an eco-run when a predetermined eco-run condition is satisfied, for example, when the vehicle is stopped such as waiting for a signal, and when the predetermined eco-run end condition is separately met, 26 is restarted.

  The engine ECU 56 is configured to output an engine stop signal as vehicle information to the air conditioner ECU 52 at the start of the eco-run and output an engine start signal as the vehicle information at the end of the eco-run. On the other hand, the air conditioner ECU 52 outputs an engine start request signal to the engine ECU 56 when the blown air temperature Te exceeds a predetermined threshold during the eco-run period. The air conditioner ECU 52 operates the water pump 30 when there is a cooling request, and stops the water pump 30 when there is no cooling request (including a mixing request with warm air) in both cases of driving and eco-run. It is configured.

  Next, the operation of the first embodiment will be described.

  In the vehicle air conditioner 10 configured as described above, the compressor 12 is operated by the power of the engine 26 while the automobile is running, and the refrigerant flows in the order of the condenser 14, the expansion valve 16, the evaporator 18, and the compressor 12, and the first loop. Circulate 20. Thereby, a refrigerating cycle is performed.

  At this time, the air conditioner ECU 52 operates the water pump 30, and the liquid refrigerant circulates through the second loop 28. The liquid refrigerant exchanges heat with the refrigerant in the first loop 20 by the evaporator 18, evaporates the refrigerant to complete the refrigeration cycle, and is cooled by the refrigerant in the first loop 20 (stores cold energy). And this liquid refrigerant cools the air-conditioner blowing air which the air-conditioning blower 46 blows in the indoor heat exchanger 32 (the cold heat stored in the second loop 28 which is a closed space is gradually consumed). Thereby, the passenger compartment is cooled.

  Then, for example, when the vehicle is stopped due to a signal waiting or the like and the engine ECU 56 determines that a predetermined eco-run condition is satisfied, the engine ECU 56 stops the engine 26 and outputs an engine stop signal to the air conditioner ECU 52. The air conditioner ECU 52 maintains the operation of the water pump 30 even when the compressor 12 (engine 26) is stopped. For this reason, the liquid refrigerant in which the cold heat is stored circulates in the second loop 28, and the liquid refrigerant cools the air blower air while consuming the cold heat in the indoor heat exchanger 32. Thereby, the cooling is maintained for a certain time after the engine 26, that is, the compressor 12 is stopped, and the comfort in the vehicle interior is maintained.

  During this eco-run period, the air conditioner ECU 52 stores in the liquid refrigerant of the second loop 28, in other words, when a signal corresponding to the blown air temperature Te exceeding the predetermined threshold value is input from the temperature sensor 54. When the cooling heat is consumed and cooling cannot be maintained, an engine start request signal is output to the engine ECU 56. As a result, the engine 26 and the compressor 12 are operated, and cooling by the refrigeration cycle and cold storage to the refrigerant in the second loop 28 are performed (resumed).

  Here, in the vehicle air conditioner 10, the liquid refrigerant of the second loop 28 can be circulated through the evaporator 18 to store cold heat in the liquid refrigerant. There is no need to provide an air heat exchanger that is not used for cooling, and the structure is simple. From another viewpoint, the evaporator and the regenerator (the regenerator of the circulating liquid refrigerant) are realized by one heat exchanger.

  Thus, in the vehicle air conditioner 10 according to the present embodiment, it can be easily configured without providing a large number of cold storage agents, and cold heat can be stored in the second loop 28.

  In addition, since the indoor heat exchanger 32 provided in the second loop 28 is arranged in the air conditioning case 34 and cools the air blower air, the evaporator 18 is connected to the refrigerant of the first loop 20 and the second loop 28. Only the heat exchange with the liquid refrigerant can be performed (the evaporator 18 does not bear the cooling of the air-conditioner blowout air). For this reason, the evaporator 18 is designed to improve heat exchange efficiency by making its outer shell a heat insulating structure.

  In the above-described embodiment, the control method in which the water pump 30 is simply operated during the eco-run period is shown. However, the present invention is not limited to this, and for example, the blowout is performed according to the cooling load estimated by the air conditioner ECU 52 or the like. The water pump 30 is stopped until the temperature Te exceeds a predetermined threshold value, or the amount of liquid refrigerant circulated by the water pump 30 is changed at any time so that the blown-out temperature Te falls within the target range (for example, even in intermittent operation, the rotational speed Various control methods may be employed. Further, the present invention is not limited to the configuration in which the cold energy stored in the second loop 28 is used for maintaining the cooling during the eco-run. For example, the electromagnetic clutch 22 is disconnected during vehicle acceleration to ensure the power performance. The liquid refrigerant stored cold by the operation of the water pump 30 may be circulated to maintain the cooling.

  Moreover, in the said embodiment, although it was set as the structure which provided the indoor heat exchanger 32 on the 2nd loop 28, this invention is not limited to this, For example, the evaporator 18 is arrange | positioned in the air-conditioning case 34, and is air-conditioned. The second loop 28 (internal liquid refrigerant) may be used as a heat insulating structure and used only for cold storage while being used for cooling the machine blowing air. Furthermore, it is also possible to use the indoor heat exchanger 32 and the evaporator 18 directed to the second loop 28 as heat exchangers for cooling the passenger compartment from different positions in the vehicle.

  Furthermore, in the above-described embodiment, an example in which the air conditioner ECU 52 and the engine ECU 56 are separate control devices has been described. However, the present invention is not limited to this, and for example, the air conditioner ECU 52 or a part of these functions is provided in the engine ECU 56. It may be configured to be integrated with.

1 is a block diagram showing a schematic overall configuration of a vehicle air conditioner according to an embodiment of the present invention. It is a schematic sectional side view which shows arrangement | positioning of the evaporator which comprises the vehicle air conditioner which concerns on embodiment of this invention, and an indoor heat exchanger.

Explanation of symbols

10 Vehicle air conditioners 12 Compressors
14 Condenser
16 Expansion valve (pressure reduction means)
18 Evaporator
28 Second loop (circulation path)
30 Water pump (liquid feeding device)
32 Indoor heat exchanger 52 Air conditioner ECU (control device)

Claims (3)

A vehicle air conditioner that performs a refrigeration cycle by circulating a refrigerant in a compressor, a condenser, a decompression unit, and an evaporator,
A vehicle air conditioner including a circulation path for circulating a liquid refrigerant that exchanges heat with the refrigerant that performs the refrigeration cycle in the evaporator and a liquid feeding device.   The vehicle air conditioner according to claim 1, wherein an indoor heat exchanger for exchanging heat between the liquid refrigerant and air blower air is provided in the circulation path.   The vehicle air conditioner according to claim 2, wherein the liquid feeding device is an electric pump that is operated by a control device when a cooling request is made while the compressor is stopped.

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