JP2010013044A - Air-conditioning system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-conditioning system for a vehicle performing heating operation feeding heating air with high quality into a cabin without accompanying with reduction of heating efficiency. <P>SOLUTION: The air-conditioning system for the vehicle includes a first air-feeding passage 14 and a second air-feeding passage 15 flowing with blown air introduced from an air introduction port 16; a heater core 52 arranged in the first air-feeding passage 14 and heating the blown air while making a high pressure side of a refrigeration cycle as a heat source; and an evaporator 46 arranged in the second air-feeding passage 15 and cooling the blown air while making a low pressure side of the refrigeration cycle as a heat source. In the heating operation, when an exit side cooling air temperature of the evaporator 46 is lower than an external air temperature, at least a part of the cooling air passed through the evaporator 46 is discharged to the outside of the cabin, and when the exit side cooling air temperature of the evaporator 46 is higher than the external air temperature, the cooling air passed through the evaporator 46 is returned to an upstream side of the heater core 52. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle air conditioning system capable of cooling operation and heating operation.

  A conventional vehicle air conditioning system of this type is disclosed in Patent Document 1. As shown in FIG. 10, the vehicle air conditioning system 100 includes a front unit 101 and a rear unit 110. In the front unit 101, a front-side internal heat exchanger 121 of the heat pump type cooling device 120 and a heater core 131 of the engine cooling circulation device 130 are arranged in this order. An air inlet 102 is provided at the upstream end of the front unit 101, and a plurality of indoor outlets 103 are provided at the downstream end of the front unit 101. In the rear unit 110, a rear-side internal heat exchanger 122 of the heat pump type cooling device 120 is disposed. An air inlet 111 is provided at the upstream end of the rear unit 110, and an outdoor outlet 113 is provided along with the indoor outlet 112 at the downstream end of the rear unit 110. The open / close ratio of the indoor outlet 112 and the outdoor outlet 113 is adjusted by the exhaust door 114.

  The heat pump cooling device 120 includes a compressor 123 that compresses a refrigerant, an external condenser 124, the above-described front-side internal heat exchanger 121, the above-described rear-side internal heat exchanger 122, and a sub heat exchanger 125. In the cooling operation, the front side internal heat exchanger 121 and the rear side internal heat exchanger 122 function as evaporators, and in the heating operation, the front side internal heat exchanger 121 and the rear side internal heat exchanger 122 function as capacitors. In the heat recovery heating operation, the refrigerant path and the refrigerant pressure can be adjusted so that the front side internal heat exchanger 121 functions as a condenser and the rear side internal heat exchanger 122 functions as an evaporator.

  In the heating operation, the air blown into the rear unit 110 is heated by the rear-side internal heat exchanger 122, and hot air obtained by this heating is supplied from the indoor outlet 112 into the vehicle interior. Thereby, the rear side room is heated.

  In the heat recovery heating operation, the air blown into the rear unit 110 is heat-exchanged with the refrigerant in the rear-side internal heat exchanger 122, and the cold air obtained by the heat exchange is exhausted from the outdoor outlet 113 to the outside of the vehicle.

The refrigerant that has passed through the rear-side internal heat exchanger 122 absorbs heat by heat exchange with the air and becomes high temperature. When this high-temperature refrigerant is compressed by the compressor 123, the higher-temperature refrigerant is discharged, so that the heating performance is improved. That is, the heat of the air blown out of the passenger compartment is recovered by the refrigerant to improve the heating performance.
JP 2000-62449 A

  By the way, when the air in the passenger compartment is exhausted outside the passenger compartment, the same amount of outside air is introduced into the passenger compartment. Therefore, when the temperature of the blast that has passed through the rear side internal heat exchanger 122 is higher than the outside air temperature, the outside air having a temperature lower than the exhausted air temperature is introduced into the vehicle interior, so that the heating performance is reduced by that amount. There is a problem of doing. In particular, when the outside air temperature is extremely low, the difference between the temperature of the air to be exhausted and the outside air temperature may become large, and in this case, a situation in which the heating performance is greatly reduced occurs.

  Here, when the temperature of the blast that has passed through the rear side internal heat exchanger 122 is higher than the outside air temperature, it may be introduced into the vehicle interior without exhausting, but it has passed through the rear side internal heat exchanger 122. Since the air is cold air, if this cold air is introduced into the vehicle compartment as it is, the feeling of heating is remarkably hindered, and high heating air in the compartment is not supplied to the vehicle interior.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle air conditioning system capable of performing a heating operation that does not cause a decrease in heating efficiency and can supply high-quality heating air to the passenger compartment.

  The invention of claim 1 which achieves the above object is arranged in the first air passage and the second air passage, and the first air passage through which the air introduced from the air introduction port respectively flows, and the air is sent using the high-pressure side of the refrigeration cycle as a heat source. A heater core that heats the air, an evaporator that is disposed in the second air passage and that cools the air using the low pressure side of the refrigeration cycle as a heat source, and an air outlet that is provided downstream of both the heater core and the evaporator and that introduces the air that flows into the vehicle interior And an evaporator outlet cold air temperature detecting means for detecting the outlet-side cold air temperature of the evaporator, and an outside air temperature detecting means for detecting the outside air temperature, and at least the heater core and the evaporator using the cold air that has passed through the evaporator Cooling operation that lowers the temperature, and warm air that raises the passenger compartment temperature using at least hot air that has passed through the heater core and the heater core. In the heating operation, if the cold air temperature at the outlet side of the evaporator is lower than the outside air temperature, at least part of the cold air that has passed through the evaporator is exhausted outside the passenger compartment, and the cold air temperature at the outlet side of the evaporator is outside air. When the temperature is higher than the temperature, the cool air that has passed through the evaporator is returned to the upstream side of the heater core.

  A second aspect of the present invention is the vehicle air conditioning system according to the first aspect, wherein the heater core and the evaporator are cycle components of a cooling and heating refrigerant circulation device, and the cooling and heating refrigerant circulation device performs heat exchange by changing latent heat. A heat pump type cooling device having a first circulation path through which the first refrigerant that circulates is circulated, and a second refrigerant that is fluid and circulates heat by sensible heat change separately from the first circulation path. A heating circulation device having two circulation paths, and the first circulation path of the heat pump type cooling device is disposed in the compressor for compressing the first refrigerant and the second circulation path, and the heat of the first refrigerant is A condenser that dissipates heat to the refrigerant of 2, an expansion unit that expands the first refrigerant, and an evaporator that cools the air by exchanging heat between the first refrigerant expanded by the expansion unit and the air, Heating circulation The second circulation path of the apparatus includes a pump that circulates the second refrigerant, a heater that heats the second refrigerant, a heater core that heats the air by exchanging heat between the second refrigerant and the air, And a radiator that dissipates heat of the refrigerant.

  A third aspect of the present invention is the vehicle air conditioning system according to the second aspect, wherein in the heating operation, the compressor is stopped at a passenger compartment temperature at which the refrigerant pressure on the inlet side of the compressor may be less than atmospheric pressure. The compressor is driven when the refrigerant pressure on the inlet side of the compressor reaches a passenger compartment temperature that is equal to or higher than atmospheric pressure.

  The invention according to claim 4 is the vehicle air conditioning system according to claim 2 or claim 3, wherein the output is sufficient to compensate for the shortage of the heating capacity of the compressor in the heating operation and in the driving state of the compressor. The heating output of the heater is controlled.

  A fifth aspect of the present invention is the vehicle air conditioning system according to the second or third aspect, wherein the outlet side refrigerant temperature of the heater core is the refrigerant at the outlet side of the compressor in the heating operation and in the driving state of the compressor. The heating capacity of the heater is controlled so as to be lower than the temperature.

  A sixth aspect of the present invention is the vehicle air conditioning system according to any one of the second to fifth aspects, wherein the second refrigerant is a liquid, and the condenser is disposed in the second circulation path. It is characterized by.

  A seventh aspect of the present invention is the vehicle air conditioning system according to any one of the second to sixth aspects, wherein the condenser is disposed upstream of the heater and downstream of the radiator in the second circulation passage. It is provided.

  The invention of claim 8 is the vehicle air conditioning system according to any one of claims 2 to 7, wherein the first refrigerant is carbon dioxide.

  The invention of claim 9 is the vehicle air conditioning system according to any one of claims 1 to 8, wherein the evaporator outlet side cold air temperature is lower than the outside air temperature and the temperature difference is small. If only a part of the cold air that has passed through the evaporator is exhausted outside the vehicle compartment and the other cold air is introduced into the vehicle interior, the evaporator outlet cold air temperature is lower than the outside air temperature and the temperature difference is large. All the cool air that has passed through the evaporator is exhausted outside the passenger compartment.

  According to the first aspect of the present invention, when the outlet outlet cold air temperature of the evaporator is lower than the outside air temperature, at least a part of the cold air that has passed through the evaporator is exhausted outside the vehicle compartment, but is higher than the cold air exhausted outside the vehicle interior. Since the outside air is introduced into the passenger compartment, the heating efficiency is improved. Also, when the evaporator outlet side cold air temperature is higher than the outside air temperature, the cold air that has passed through the evaporator is returned to the upstream side of the heater core, so that outside air having a temperature lower than that of the evaporator outlet side cold air is introduced into the vehicle interior. There is no. In addition, the cool air that has passed through the evaporator is not mixed with the warm air that has passed through the heater core and introduced into the vehicle interior, but is heated again through the heater core and then introduced into the vehicle interior. As a result, high-quality heating air without temperature unevenness can be introduced into the passenger compartment. As described above, it is possible to perform a heating operation that can supply high-quality heating air to the passenger compartment without lowering the heating efficiency.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1, the first refrigerant of the heat pump type cooling device can be circulated through the first circulation path through a constant path regardless of the heating operation and the cooling operation. Therefore, the configuration of the heat pump type cooling device may be simple. The heating circulation device may be configured to circulate the second refrigerant that receives heat from the condenser through a path passing through the heater core and the radiator. Then, the heat received from the condenser is dissipated to the outside air by the radiator, or the heat received from the condenser is dissipated from the heater core to the vehicle interior, so that both cooling and heating can be performed. As described above, in a system that performs heating and cooling using a heat pump type cooling device, the configuration of the heat pump type cooling device can be simplified and the entire air conditioning system can be configured simply.

  According to the invention of claim 3, in addition to the effect of the invention of claim 2, when the refrigerant pressure on the inlet side of the compressor becomes less than atmospheric pressure, moisture, air, etc. enter the first circulation path of the heat pump type cooling device. Although problems such as corrosion occur, such problems can be prevented. In addition, when the refrigerant pressure at the inlet side of the compressor becomes less than atmospheric pressure, the refrigerant flow rate is remarkably reduced, and accordingly, the amount of oil returned to the compressor is reduced, which may cause destruction of the compressor due to poor lubrication. However, such a problem can be prevented.

  According to the invention of claim 4, in addition to the effect of the invention of claim 2 or claim 3, a compressor having a higher coefficient of performance (COP) than the heater is operated to the maximum extent to save power. Can do.

  According to the invention of claim 5, in addition to the effect of the invention of claim 2 or claim 3, the heat of the first refrigerant can be surely radiated to the second refrigerant by the condenser, and the heat pump type cooling device The operating efficiency as a heating source can be improved. This also saves power as a system.

  According to the invention of claim 6, in addition to the effects of the inventions of claims 2 to 5, since the capacitor is a so-called water-cooled type, the heat conductivity is higher than that of the air-cooled type, so that the size can be reduced. It is possible to reduce the passage resistance of the refrigerant. Therefore, the required power of the compressor is reduced by the amount corresponding to the reduction of the passage resistance, so that the driving force of the compressor can be saved and the compressor can be reduced in size.

  According to the invention of claim 7, in addition to the effects of the inventions of claims 2 to 6, the capacitor whose surface temperature is lower than that of the heater performs heat exchange with the second refrigerant prior to the heater. The temperature difference between the two refrigerants can be made as large as possible, and the heat exchange efficiency in the capacitor can be improved.

  According to the invention of claim 8, in addition to the effects of the inventions of claims 2 to 7, since the first refrigerant is carbon dioxide, the refrigerant density is large and the discharge temperature of the compressor is high. The heating performance of the device will be excellent. Further, since the saturation pressure is high even in a low temperature state, the flow rate of the refrigerant can be secured more reliably, and the heat pump type cooling device can be used as a heat source even in a low temperature environment.

  According to the ninth aspect of the invention, in addition to the effects of the first to eighth aspects of the invention, it is possible to prevent the uncomfortable feeling of heating as much as possible during the transition from the introduction of outside air to the introduction of inside air.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
1 to 9 show an embodiment of the present invention. FIG. 1 is a schematic configuration diagram of an air conditioning unit of a vehicle air conditioning system, FIG. 2 is a schematic configuration diagram of a cooling / heating refrigerant circulation device of the vehicle air conditioning system, and FIG. 3 is a schematic control block diagram of the vehicle air conditioning system, 4 is a control flowchart of the cooling and cooling refrigerant circulation device during heating operation, FIG. 5 is an intake side control flowchart of the air conditioning unit during heating operation, and FIG. 6 is a characteristic diagram illustrating control of the compressor and electric heater during heating operation. 7 is a schematic configuration diagram showing a full outside air introduction state of the air conditioning unit, FIG. 8 is a schematic configuration diagram showing a half outside air / inside air introduction state of the air conditioning unit, and FIG. 9 is a schematic configuration diagram showing a full inside air introduction state of the air conditioning unit. is there.

  1 and 2, an air conditioning system for a vehicle includes an air conditioning unit 10 arranged outside a vehicle compartment of the vehicle, and a refrigerant circulation for air conditioning that uses an evaporator 46 and a heater core 52 arranged in the air conditioning unit 10 as cycle components. Device 40.

  The air conditioning unit 10 has a unit case 11 as shown in detail in FIG. The unit case 11 includes an intake case 12 and a main body case 13 to which the intake case 12 is connected. A first air passage 14 and a second air passage 15 for creating conditioned air are provided in the intake case 12 and the main body case 13, respectively. The intake case 12 is provided with an air inlet 16 for introducing air into the first air passage 14 and the second air passage 15.

  The air introduction port 16 includes a first inside air introduction port 17 that opens to the first air passage 14, an outside air introduction port 18 that also opens to the first air passage 14, and a second inside air introduction port that opens to the second air passage 15. 19. The first inside air introduction port 17 and the second inside air introduction port 19 each open to the vehicle interior, and the outside air introduction port 18 opens to the outside of the vehicle interior. The intake case 12 is provided with an inside / outside air switching door 20 that adjusts the amount of inside air introduced from the first inside air introduction port 17 (the amount of air in the vehicle interior) and the amount of outside air introduced from the outside air introduction port. The inside / outside air switching door 20 changes between the full inside air introduction position (see FIG. 9) at the solid line position in FIG. 1 and the full outside air introduction position (see FIG. 7) at the virtual line position in FIG. The open / close ratio of the inside air introduction port 17 and the outside air introduction port 18 can be adjusted. An intermediate position between the full inside air position and the full outside air position is a semi-outside air / inside air introduction position (see FIG. 8).

  A first blower fan 21 and a second blower fan 22 are arranged in the first air passage 14 and the second air passage 15 of the intake case 12, respectively. The first blower fan 21 sucks the inside air and the outside air into the first air passage 14. The second blower fan 22 sucks the inside air into the second air passage 15.

  A heater core 52 of the cooling / heating refrigerant circulation device 40 is disposed in the first air passage 14 of the main body case 13, and an evaporator 46 of the cooling / heating refrigerant circulation device 40 is disposed in the second air passage 15. The heater core 52 heats the air blown from the first air passage 14 to produce hot air. The evaporator 46 cools the air blown from the second air passage 15 and produces cold air. The configuration of the cooling / heating refrigerant circulating device 40 will be described in detail below.

  An air distribution door 23 is provided immediately upstream of the heater core 52 and the evaporator 46 of the main body case 13. The air distribution door 23 can change between a position where all the air introduced into the first air passage 14 and the second air passage 15 is sent to the heater core 52 and a position where all the air sent to the evaporator 46 is sent to the heater core 52. The ratio of the amount of air blown to the evaporator 46 can be adjusted. In the middle position of the solid line in FIG. 1, the air introduced from the first air passage 14 is distributed to the heater core 52, and the air introduced from the second air passage 15 is distributed to the evaporator 46.

  Immediately downstream of the heater core 52 and the evaporator 46 of the main body case 13, a mix chamber 24 where the first air passage 14 and the second air passage 15 merge is provided and a mix door 25 is provided. In the mix chamber 24, hot air from the heater core 52 and cold air from the evaporator 46 are mixed or discharged without being mixed depending on the position of the mix door 25. The mix door 25 can change between the full heating position of the solid line position in FIG. 1 and the full cooling position of the virtual line in FIG. The mix chamber 24 is also provided with a differential outlet 26, a vent outlet 27, and a foot outlet 28, which are blower outlets, and air is guided from the outlets 26, 27, and 28 into the vehicle interior. The differential outlet 26 is opened / closed by a differential door 29, the vent outlet 27 is opened / closed by a vent door 30, and the foot outlet 28 is opened / closed by a foot door 31 according to the blowing mode.

  The intake case 12 and the main body case 13 are provided with a cold air return path 32. The cold air recirculation path 32 has a cold air recirculation inlet 32 a immediately downstream of the evaporator 46, and a cold air recirculation outlet 32 b further upstream of the first blower fan 21 in the first air passage 14 (position upstream of the heater core 52). The cold air recirculation inlet 32 a is opened and closed by a recirculation door 33. An exhaust port 34 that opens to the outside of the passenger compartment is provided immediately upstream of the cold air return outlet 32 b of the cold air return path 32. The exhaust port 34 is set at a position where ram pressure does not act. The open / close ratio of the cold air recirculation outlet 32 b and the exhaust port 34 can be adjusted by the exhaust door 35. The exhaust door 35 circulates all the recirculated cold air to the first air passage 14 at the solid line position in FIG. 1 and exhausts all the recirculated cold air to the outside of the vehicle compartment at the phantom line position in FIG. At the intermediate position between the solid line position in FIG. 1 and the phantom line position in FIG. 1, half of the reflux cold air is returned to the first air passage 14 and the other half is exhausted outside the passenger compartment.

  In the vehicle air conditioning system, the vehicle interior temperature detection sensor 36 that detects the temperature in the vehicle interior, the outside air temperature detection sensor 37 that is an outside air temperature detection means that detects the temperature of the outside air, and the outlet side cold air temperature of the evaporator 46 are used. An outlet cooling air temperature detection sensor 38, which is an outlet cooling air temperature detecting means for detecting, is provided.

  Next, the refrigerant circulation device 40 for air conditioning will be described. As shown in FIG. 2, the cooling and heating refrigerant circulation device 40 is configured by a combination of a heat pump type cooling device A and a heating circulation device B.

  The heat pump type cooling device A has a first circulation path 41 filled with carbon dioxide as a first refrigerant, and in this first circulation path 41, a compressor 42, a water-cooled condenser 43 as a condenser, an internal heat exchange. A vessel 44, an expansion valve 45 as an expansion means, an evaporator 46, and an accumulator 47 are provided in this order. That is, a refrigeration cycle is configured.

  The compressor 42 compresses the sucked relatively low temperature and low pressure first refrigerant and discharges it as a high temperature and high pressure refrigerant.

  The water-cooled condenser 43 is disposed in a device storage chamber 55 in the second circulation path 48 described below, and cools the first refrigerant pumped from the compressor 42 with the second refrigerant. That is, heat exchange is performed between the first refrigerant and the second refrigerant in the water-cooled condenser 43, and the second refrigerant is heated by the first refrigerant.

  The internal heat exchanger 44 exchanges heat between the first refrigerant sent from the water-cooled condenser 43 and the cooler first refrigerant sent from the accumulator 47, and the first refrigerant sent from the water-cooled condenser 43. Is further cooled.

  The expansion valve 45 expands (depressurizes) the first refrigerant that has passed through the internal heat exchanger 44 and sends it to the evaporator 46 as a low-temperature and low-pressure gas.

  The evaporator 46 uses the low pressure side of the refrigeration cycle as a heat source, and heat-exchanges the first refrigerant sent from the expansion valve 45 and the air passing through the evaporator 46 to cool the air.

  The accumulator 47 gas-liquid-separates the first refrigerant sent from the evaporator 46 and sends only the first refrigerant in the gas phase state to the internal heat exchanger 44, and temporarily stores the first refrigerant in the liquid phase state. To be stored.

  The heating circulation device B has a second circulation path 48 in which a liquid such as water or antifreeze as a second refrigerant is enclosed, and in this second circulation path 48, a pump 49, a radiator 50, and a device storage chamber. 55 and the heater core 52 are provided in this order. The device storage chamber 55 is a space having a larger cross-sectional area than the second circulation path 48, and the electric heater 51, which is a heater, is stored in the interior together with the water-cooled condenser 43.

  The pump 49 pressurizes and pumps the sucked second refrigerant in order to circulate the second refrigerant in the second circulation path 48. The liquid refrigerant pumped by the pump 49 circulates in the second circulation path 48 without changing the phase and changes in sensible heat by heat exchange.

  The radiator 50 radiates the heat of the second refrigerant to the outside air. The outside air is blown by an electric fan or traveling wind, and heat exchange is performed between the second refrigerant and the outside air.

  The electric heater 51 is provided on the downstream side of the water-cooled condenser 43 and generates heat when energized to heat the second refrigerant.

  The heater core 52 uses the high pressure side of the refrigeration cycle and the electric heater 51 as heat sources, and heat-exchanges the air that passes through the second refrigerant and the heater core 52 to heat the air.

  The second circulation path 48 is provided with a radiator bypass passage 53 that bypasses the radiator 50, and the second switching path 54 is switched by switching a passage switching valve 54 provided on the upstream side of the radiator bypass passage 53. The flow of the refrigerant can be switched to the radiator 50 side or the radiator bypass channel 53 side.

  Further, the heat pump type cooling device A is provided with a compressor outlet refrigerant temperature detection sensor 56 that detects an outlet side refrigerant temperature of the compressor 42. The heating circulation device B is provided with a heater core outlet refrigerant temperature detection sensor 57 that detects the outlet side refrigerant temperature of the heater core 52.

  Next, the control system of the vehicle air conditioning system will be briefly described. As shown in FIG. 3, the control unit 39 includes a vehicle interior temperature detection sensor 36, an outside air temperature detection sensor 37, an evaporator outlet cold air temperature detection sensor 38, a compressor outlet refrigerant temperature detection sensor 56, and a heater core outlet refrigerant temperature detection sensor 57. Each detection data is input. The control unit 39 controls the driving of the compressor 42, the pump 49, the electric heater 51, the first blower motor 21a, and the second blower motor 22a, and controls the switching of the flow path switching valve 54. Moreover, the control part 39 controls the drive of various door motor 20a, 23a, 25a, 29a, 30a, 31a, 33a, 35a. In the heating mode, the flowcharts shown in FIGS. 4 and 5 are executed. The specific contents of these flowcharts will be described in the next operation.

  Next, the operation of the vehicle air conditioning system will be described. In this air conditioning system for a vehicle, a cooling operation for lowering the vehicle interior temperature using at least the cool air that has passed through the evaporator 46 among the heater core 52 and the evaporator 46, and at least the heater core 52 that has passed through the heater core 52 and the evaporator 46. It is possible to perform a heating operation that raises the passenger compartment temperature using warm air.

  When the cooling operation is selected, the compressor 42 of the heat pump type cooling device A is driven and the pump 49 of the heating circulation device B is driven, but the electric heater 51 is not turned on. Further, the flow path switching valve 54 is normally on the radiator 50 side. Thereby, since the heat of the water-cooled condenser 43 is dissipated through the heater core 52 and the radiator 50 of the heating circulation device B, the heat pump type cooling device A absorbs heat from the air that the evaporator 46 passes through the second air passage 15. And the ventilation which passes the 2nd ventilation path 15 is made into cold wind. The cold air thus obtained is introduced as it is or air-mixed with the warm air that has passed through the heater core 52 and introduced into the passenger compartment as cold air having a desired temperature.

  As shown in FIG. 4, when the heating operation is selected (step S1), the pump 49 of the heating circulation device B is driven and the electric heater 51 is turned on (step S2). Moreover, the flow path switching valve 54 is normally on the radiator bypass flow path 53 side.

  When the electric heater 51 is turned on (step S2), it is checked whether or not the vehicle interior temperature Tr is a temperature exceeding A ° C. (for example, −10 ° C.). (Step S3). If the vehicle interior temperature Tr exceeds A ° C., the compressor 42 starts to be driven (step S4).

  Here, A ° C. is the lowest temperature at which the inlet-side refrigerant pressure of the compressor 42 is unlikely to be less than atmospheric pressure. In this embodiment, the first refrigerant is carbon dioxide (for example, R134a). It is set to −10 ° C. In other words, since R134a has a refrigerant saturation pressure of 1 atm at -26.5 ° C., the refrigerant pressure at the outlet side of the evaporator 46 will be at or above atmospheric pressure if the passenger compartment temperature Tr is -10 ° C. or more. Is set to

  When the compressor 42 is driven (step S4), control is performed to gradually reduce the output of the electric heater 51 (step S5). Specifically, the heating output of the electric heater 51 is controlled so as to compensate for the shortage of the heating capacity by the compressor 42. For example, the total heat amount of the compressor 42 of the cooling / heating refrigerant circulating device 40 and the electric heater 51 of the heating / circulating device B is set, and the output of the electric heater 51 is adjusted so as to be the set total heat amount. That is, since the amount of heat of the compressor 42 gradually increases with time since the start of operation, the amount of heat of the electric heater 51 is gradually decreased accordingly.

  Further, when the compressor 42 is driven, it is checked whether or not the vehicle interior temperature Tr exceeds the indoor target temperature Tt (step S6). When the vehicle interior temperature Tr exceeds the indoor target temperature Tt (step S6), it is checked whether or not the outlet side refrigerant temperature Th of the heater core 52 exceeds the outlet side refrigerant temperature Td of the compressor 42 (step S7). When the outlet-side refrigerant temperature Th of the heater core 52 exceeds the outlet-side refrigerant temperature Td of the compressor 42, the electric heater 51 is turned off (step S8). Thus, the outlet side refrigerant temperature Th of the heater core 52 is controlled to be lower than the outlet side refrigerant temperature Td of the compressor 42.

  In the heating operation, when the vehicle interior temperature Tr becomes A ° C. or lower due to the opening of the vehicle door or the like, the driving of the compressor 42 is stopped (step S9). When the heating operation is canceled (step S1), both the compressor 42 and the electric heater 51 are stopped (step S9).

  Next, a specific example in the case where the vehicle air conditioning system is started when the outside air is at a very low temperature (for example, −20 ° C.) will be described. As shown in FIG. 6, when the outside air temperature is −20 ° C., the passenger compartment temperature is also about −20 ° C. When the heating operation is selected (step S1), only the electric heater 51 is driven (step S2). The compressor 42 is not driven. At the start of the vehicle air conditioning system, the passenger compartment temperature is very low (for example, −20 ° C.) that is almost the same as the outside air, so that the air passing through the first air passage 14 is heated only by the heat of the electric heater 51, Hot air obtained by this heating is introduced into the passenger compartment.

  Then, the compressor 42 is driven only when the vehicle interior temperature Tr exceeds A ° C. (for example, −10 ° C.) (steps S3 and S4). Thereby, the air which passes the 1st ventilation path 14 is heated with the heat of the compressor 42, and the heat of the electric heater 51, and the warm air obtained by this heating is introduce | transduced in a vehicle interior.

  When the vehicle interior temperature Tr exceeds A ° C. (for example, −10 ° C.), control is performed to slightly reduce the output of the electric heater 51 (step S5). Further, when the outlet side refrigerant temperature Th of the heater core 52 becomes equal to or higher than the outlet side refrigerant temperature Td of the compressor 42, the electric heater 51 is turned off (step S8). Thus, the heat of the condenser 43 of the heat pump type cooling device A is reliably radiated to the heating circulation device B.

  When the outside air temperature at the start of the vehicle air conditioning system is A ° C. (for example, −10 ° C.) or more, both the electric heater 51 and the compressor 42 are driven from the start.

  Next, operations related to air introduction / exhaust in the heating operation will be described. Here, in the heating operation, the mix door 25 is positioned at the full heating position, and the reflux door 33 is positioned at the open position of the cold air reflux inlet 32a. As a result, all the cool air that has passed through the evaporator 46 is guided to the cool air recirculation path 32, and only the warm air that has passed through the heater core 52 is introduced into the vehicle interior. Based on this, the flow of the recirculated cold air and the air introduction / exhaust of the evaporator 46 will be described.

  As shown in FIG. 5, when the heating operation is selected (step S20), it is checked whether or not the outlet-side cold air temperature Tevap of the evaporator 46 is a temperature exceeding the outside air temperature Tamb (step S21). If the outlet side cold air temperature Tevap of the evaporator 46 is higher than the outside air temperature Tamb, as shown in FIG. 9, the exhaust door 35 and the inside / outside air switching door 20 are set to the full inside air position (step S23).

  If the outlet side cold air temperature Tevap of the evaporator 46 is lower than the outside air temperature Tamb, it is checked whether or not the temperature difference is equal to or higher than B ° C. (for example, 10 ° C.) (step S22). If the temperature difference is equal to or higher than B ° C., as shown in FIG. 7, the exhaust door 35 and the inside / outside air switching door 20 are set to the full outside air position (step S24). If the temperature difference is less than B ° C. (for example, 10 ° C.), as shown in FIG. 8, the exhaust door 35 and the inside / outside air switching door 20 are set to the half inside / outside air position (step S25).

  Next, a specific example when the outside air temperature at the start of the vehicle air conditioning system is extremely low (for example, −20 ° C.) will be described. If the outside air temperature Tamb is −20 ° C., the passenger compartment temperature is also about −20 ° C. When the heating operation is selected (step S20), the electric heater 51 is driven to gradually heat the passenger compartment temperature. When the passenger compartment temperature Tr reaches −10 ° C., the compressor 42 is driven, and the air passing through the second air passage 15 is cooled by the evaporator 46, and the outlet side cold air temperature Tevap of the evaporator 46 is B ° C. (for example, 10 ° C.) from the outside air temperature Tamb. The temperature is too low. Then, the exhaust door 35 and the inside / outside air switching door 20 are brought to the full outside air position shown in FIG. 7, and the cold air that has passed through the evaporator 46 is exhausted from the exhaust port 34 to the outside of the vehicle compartment through the cold air reflux path 32. Then, outside air of −20 ° C. is introduced from the outside air inlet 18. Since the introduced outside air is hotter than the cold air that has passed through the evaporator 46, heating can be performed more efficiently than when the outside air is heated.

  When the vehicle interior temperature gradually rises, the temperature of the cold air that has passed through the evaporator 46 also gradually increases, and the outlet side cold air temperature Tevap of the evaporator 46 has a temperature difference less than B ° C. (for example, 10 ° C.) from the outside air temperature Tamb. It becomes temperature. Then, the exhaust door 35 and the inside / outside air switching door 20 are set to the semi-outside air / inside air position shown in FIG. 8, and the cold air that has passed through the evaporator 46 is exhausted by half from the exhaust port 34 through the cold air recirculation path 32. Half is returned to the upstream of the heater core 52. The mixed air of the outside air and the reflux cold air flows into the first air passage 14, the mixed air is heated by the heater core 52, and the heated hot air is introduced into the vehicle interior.

  When the vehicle interior temperature further increases, the temperature of the cold air that has passed through the evaporator 46 also becomes higher, and the outlet-side cold air temperature Tevap of the evaporator 46 becomes higher than the outside air temperature Tamb. Then, the exhaust door 35 and the inside / outside air switching door 20 are set to the full inside air position shown in FIG. 9, and all the cold air that has passed through the evaporator 46 is returned to the upstream of the heater core 52. The reflux cold air is heated by the heater core 52, and the heated hot air is introduced into the vehicle interior. Since the cold air that has passed through the evaporator 46 is hotter than the outside air, heating can be performed more efficiently than heating the outside air.

  The cold air that has passed through the evaporator 46 is not mixed with the hot air that has passed through the heater core 52 downstream of the heater core 52 and introduced into the vehicle interior, but is heated again through the heater core 52 and then into the vehicle interior. Since it is introduced, high-quality heating air with no temperature unevenness is introduced as warm air into the passenger compartment.

  As described above, in this in-vehicle air conditioning system, in the heating operation, when the outlet-side cold air temperature Tevap of the evaporator 46 is lower than the outside air temperature Tamb, at least a part of the cold air that has passed through the evaporator 46 is exhausted outside the passenger compartment. When the outlet side cold air temperature Tevap of the evaporator 46 is higher than the outside air temperature Tamb, the cold air that has passed through the evaporator 46 is returned to the upstream side of the heater core 52. Therefore, when the outlet-side cold air temperature Tevap of the evaporator 46 is lower than the outside air temperature Tamb, at least a part of the cold air that has passed through the evaporator 46 is exhausted outside the vehicle compartment, but outside air that is hotter than the cold air exhausted outside the vehicle interior is exhausted. Since it is introduced into the passenger compartment, the heating efficiency is improved. Further, when the outlet-side cold air temperature Tevap of the evaporator 46 is higher than the outside air temperature Tamb, the cold air that has passed through the evaporator 46 is returned to the upstream side of the heater core 52, so that the outside air having a lower temperature than the outlet-side cold air of the evaporator 46 is It is not introduced indoors. In addition, the cool air that has passed through the evaporator 46 is not mixed with the hot air that has passed through the heater core 52 downstream of the heater core 52 and introduced into the vehicle interior. Therefore, high-quality heating air with no temperature unevenness is introduced into the passenger compartment as hot air. As described above, it is possible to perform a heating operation that can supply high-quality heating air to the passenger compartment without lowering the heating efficiency.

  In this embodiment, the heater core 52 uses the high-pressure side of the refrigeration cycle and the electric heater 51 as heat sources, but uses only the high-pressure side of the refrigeration cycle as a heat source, and exchanges heat between the second refrigerant and the air passing through the heater core 52. You may comprise so that ventilation may be heated.

  In this embodiment, the heater core 52 and the evaporator 46 are cycle components of the cooling / heating refrigerant circulation device 40, and the cooling / heating refrigerant circulation device 40 circulates a first refrigerant that exchanges heat by changing latent heat. Separately from the heat pump type cooling device A having the path 41 and the first circulation path 41, a heating circulation apparatus having a second circulation path 48 in which a second refrigerant that is a fluid and performs heat exchange by sensible heat change circulates. B, the first circulation path 41 of the heat pump type cooling device A is disposed in the compressor 42 that compresses the first refrigerant and the second circulation path 48, and the heat of the first refrigerant is transferred to the second refrigerant. A water-cooled condenser 43 that dissipates heat, an expansion valve 45 that expands the first refrigerant, and an evaporator 46 that cools the air by exchanging heat between the first refrigerant expanded by the expansion valve 45 and the air. The second circulation path 48 of the heating circulation device B has heat between the pump 49 that circulates the second refrigerant, the electric heater 51 that heats the second refrigerant, and the second refrigerant and the blower air. It has the heater core 52 which heats ventilation by replacing | exchanging, and the heat radiator 50 which radiates the heat | fever of a 2nd refrigerant | coolant.

  Accordingly, the first refrigerant of the heat pump cooling device A only needs to be circulated through the first circulation path 41 regardless of the heating operation and the cooling operation. Therefore, the configuration of the heat pump cooling device A may be simple. . The heating / circulation device B may also be configured to circulate the second refrigerant that receives heat from the water-cooled condenser 43 along a path that passes through the heater core 52 and the radiator 50. Then, the heat received from the water-cooled condenser 43 is radiated to the outside air by the radiator 50, and the heat received from the water-cooled condenser 43 is radiated from the heater core 52 to the vehicle interior, so that both cooling and heating can be performed. As mentioned above, in the system which heats and cools using the heat pump type cooling device A, the configuration of the heat pump type cooling device A can be simplified and the entire air conditioning system can be configured simply.

  In this embodiment, the heater core 52 and the evaporator 46 are cycle components of the cooling / heating refrigerant circulation device 40 having the above-described configuration, and the heater core 52 heats air by using the high-pressure side of the refrigeration cycle as a heat source. Uses the low pressure side of the refrigeration cycle as a heat source to cool the air. The heater core 52 is configured to exchange heat using the secondary refrigerant between the refrigerant in the refrigeration cycle and the air sent to the room, but directly exchanges heat between the refrigerant in the refrigeration cycle and the air sent to the room. You may comprise as follows. The evaporator 46 is configured to directly exchange heat between the refrigerant in the refrigeration cycle and the air blown into the room, but uses the secondary refrigerant to exchange heat between the refrigerant in the refrigeration cycle and the air blown into the room. You may comprise as follows.

  In this embodiment, in the heating operation, at the passenger compartment temperature at which the inlet-side refrigerant pressure of the compressor 42 may be less than atmospheric pressure, the compressor 42 is stopped and the inlet-side refrigerant pressure of the compressor 42 is equal to or higher than atmospheric pressure. When the vehicle interior temperature is reached, the compressor 42 is driven. Therefore, when the refrigerant pressure on the inlet side of the compressor 42 is less than atmospheric pressure, moisture, air, etc. enter the first circulation path 41 of the heat pump type cooling device A, causing problems such as corrosion. Can be prevented. Further, when the refrigerant pressure at the inlet side of the compressor 42 becomes less than the atmospheric pressure, the refrigerant flow rate is remarkably reduced. As a result, the amount of oil returned to the compressor 42 is reduced, and the compressor 42 may be destroyed due to poor lubrication. However, such problems can be prevented.

  In this embodiment, in the heating operation and in the driving state of the compressor 42, the heating output of the electric heater 51 is controlled so as to compensate for the shortage of the heating capacity of the compressor 42. Therefore, since the compressor 42 having a higher coefficient of performance (COP) than the electric heater 51 is operated as effectively as possible, power saving can be achieved.

  In this embodiment, control is performed to reduce the output of the electric heater 51 when the vehicle interior temperature Tr exceeds A ° C. (for example, −10 ° C.). However, the vehicle interior temperature Tr exceeds the indoor target temperature Tt. You may control to reduce the output of the electric heater 51 at the time. By controlling in this way, the immediate warming performance is improved.

  In this embodiment, when the vehicle interior temperature Tr exceeds the indoor target temperature Tt in the heating operation and in the driving state of the compressor 42, the outlet side refrigerant temperature Th of the heater core 52 becomes the outlet side refrigerant temperature Td of the compressor 42. The heating output of the electric heater 51 was controlled to be lower. Therefore, the heat | fever of a 1st refrigerant | coolant can be reliably radiated | emitted to the 2nd refrigerant | coolant with the capacitor | condenser 43, and the operating efficiency as a heating source of the heat pump type cooling device A can be improved. This also saves power as a system.

  In this embodiment, when the outlet-side cold air temperature Tevap of the evaporator 46 is lower than the outside air temperature Tamb and the temperature difference is small (less than B ° C.), only a part of the cold air that has passed through the evaporator 46 is placed outside the passenger compartment. When the exhaust air is exhausted and another cold air is introduced into the passenger compartment, and the outlet-side cold air temperature Tevap of the evaporator 46 is lower than the outside air temperature Tamb and the temperature difference is large (B ° C. or more), the cold air that has passed through the evaporator 46 All of these were configured to exhaust outside the passenger compartment. Therefore, it is possible to prevent the uncomfortable feeling of heating as much as possible during the transition from the introduction of outside air to the introduction of inside air.

  In this embodiment, since the inside / outside air switching door 20 is similarly switched in conjunction with the exhaust door 35, when the inside air is discharged from the exhaust port 34 to the outside of the passenger compartment, the outside air enters from the outside air introduction port 18, The outside air that has entered always passes through the heater core 52 and is introduced into the passenger compartment. Therefore, it is possible to avoid as much as possible the situation where outside air enters through the gap between the doors of the vehicle, and the interior of the vehicle can be made a high-quality heating space.

  In this embodiment, since the condenser is a so-called water-cooled type, that is, a water-cooled condenser 43, the thermal conductivity is higher than that of the air-cooled type, so that it can be made compact and the passage resistance of the first refrigerant can be reduced. Therefore, the required power of the compressor 42 is reduced by the amount corresponding to the reduction of the passage resistance, so that the driving force of the compressor 42 can be saved and the compressor 42 can be downsized.

  In this embodiment, since the water-cooled condenser 43 is disposed on the upstream side of the electric heater 51, the water-cooled condenser 43 whose surface temperature is lower than that of the electric heater 51 performs heat exchange with the second refrigerant before the electric heater 51. The temperature difference between the water-cooled condenser 43 and the second refrigerant can be made as large as possible, and the heat exchange efficiency in the water-cooled condenser 43 can be improved.

  In this embodiment, since the first refrigerant is carbon dioxide, the refrigerant density is large and the discharge temperature of the compressor 42 is high, so that the heating performance of the heat pump type cooling device A is excellent. Further, since the saturation pressure is high even in a low temperature state (for example, −10 ° C.), the flow rate of the refrigerant can be ensured by that amount, and the heat pump type cooling device A can be used as a heat source even in a low temperature environment.

  In this embodiment, the cool air return path 32 returns the cool air further upstream than the first blower fan 21, so that the cool air returned from the cool air return path 32 and the air introduced from the air inlet 16 are the first blower fan. After being stirred by the heater 21, the air is guided to the heater core 52, so that the cool air without temperature unevenness is guided to the heater core 52, and the warm air without temperature unevenness is discharged from the heater core 52. Therefore, air mix property improves.

  In the heating operation, the cold air that has passed through the evaporator 46 is introduced into the passenger compartment or returned to the upstream of the heater core 52 by comparing the temperature of the cold air that has passed through the evaporator 46 and the outside air temperature. The heating operation is not limited to the heating operation shown in the above-described embodiment, and may be any operation that raises the vehicle interior temperature using at least the warm air that has passed through the heater core 52 out of the heater core 52 and the evaporator 46.

  Whether or not to perform the heating operation may be configured to be manually selected by the user, or may be configured to automatically determine whether or not to perform the heating operation. As a method for automatically determining the heating operation, it is determined whether or not the detected outside air temperature is lower than a predetermined temperature, or whether or not the difference between the detected indoor temperature and the target indoor temperature is equal to or higher than a predetermined temperature. There are various determination methods.

(Other)
In the above embodiment, the electric heater 51 is used as the heater, but the same action and effect can be obtained even if a combustion heater or the like is used.

  In the above embodiment, carbon dioxide is used as the first refrigerant, and liquid such as water or antifreeze liquid is used as the second refrigerant, but it goes without saying that other than these may be used as the refrigerant.

1 is a schematic configuration diagram of an air conditioning unit of a vehicle air conditioning system according to an embodiment of the present invention. 1 shows an embodiment of the present invention and is a schematic configuration diagram of a refrigerant circulation device for cooling and heating of an air conditioning system for a vehicle. 1 is a schematic control block diagram of a vehicle air conditioning system according to an embodiment of the present invention. It is control flowchart of the refrigerant | coolant circulation device for air conditioning which shows one Embodiment of this invention at the time of heating operation. It is an intake side control flowchart of the air conditioning unit at the time of heating operation, showing an embodiment of the present invention. It is a characteristic diagram which shows one Embodiment of this invention and demonstrates control of the compressor and electric heater at the time of heating operation. It is a schematic block diagram which shows one Embodiment of this invention and shows the full external air introduction | transduction state of an air conditioning unit. It is a schematic block diagram which shows one Embodiment of this invention and shows the semi-outside air / inside air introduction state of an air conditioning unit. It is a schematic block diagram which shows one Embodiment of this invention and shows the full inside air introduction state of an air conditioning unit. It is a schematic block diagram of the vehicle air conditioning system of a prior art example.

Explanation of symbols

A heat pump type cooling device B heating circulation device 14 first air passage 15 second air passage 16 air inlet 26 differential outlet (air outlet)
27 Vent outlet (air outlet)
28 Foot outlet (air outlet)
37 Outside temperature detection sensor (outside temperature detection means)
38 Eve outlet cold air temperature detection sensor (Eve outlet cold air temperature detection means)
40 Refrigerating / circulating device for air conditioning 41 First circulation path 42 Compressor 43 Water-cooled condenser (condenser)
45 Expansion valve (expansion means)
46 Evaporator 48 Second circulation path 49 Pump 50 Radiator 51 Electric heater (heater)
52 Heater core

Claims (9)

Arranged in the first air passage (14) and the second air passage (15) through which the air introduced from the air introduction port (16) flows, and the first air passage (14), the high pressure side of the refrigeration cycle is used as a heat source. A heater core (52) that heats the air, an evaporator (46) that is disposed in the second air passage (15) and cools the air using the low-pressure side of the refrigeration cycle as a heat source, the heater core (52), and the evaporator (46) ) And an outlet outlet cold air temperature detection for detecting the outlet side cold air temperature of the air outlets (26), (27), (28) and the evaporator (46) for introducing the incoming air flow into the vehicle interior. Means (38) and outside air temperature detecting means (37) for detecting outside air temperature,
Of the heater core (52) and the evaporator (46), at least cooling air that has passed through the evaporator (46) is used to lower the vehicle interior temperature, and the heater core (52) and the evaporator (46) , At least a heating operation for raising the passenger compartment temperature using the warm air that has passed through the heater core (52),
In the heating operation, when the cold air temperature at the outlet side of the evaporator (46) is lower than the outside air temperature, at least a part of the cold air that has passed through the evaporator (46) is exhausted outside the passenger compartment, and the outlet side of the evaporator (46). When the cold air temperature is higher than the outside air temperature, the cold air that has passed through the evaporator (46) is returned to the upstream side of the heater core (52). The vehicle air conditioning system according to claim 1,
The heater core (52) and the evaporator (46) are cycle components of a cooling and heating refrigerant circulation device (40).
The cooling / heating refrigerant circulation device (40) includes a heat pump type cooling device (A) having a first circulation path (41) through which a first refrigerant that performs heat exchange by latent heat changes, and the first circulation path (41). And a heating circulation device (B) having a second circulation path (48) through which a second refrigerant that exchanges heat by changing sensible heat circulates.
The first circulation path (41) of the heat pump type cooling device (A) is disposed in the compressor (42) for compressing the first refrigerant and the second circulation path (48), and the first refrigerant path (41) Heat is generated between the condenser (43) that radiates heat to the second refrigerant, the expansion means (45) that expands the first refrigerant, and the first refrigerant expanded by the expansion means (45) and the air blowing. The evaporator (46) for cooling by replacing the air flow,
The second circulation path (48) of the heating circulation device (B) includes a pump (49) for circulating the second refrigerant, a heater (51) for heating the second refrigerant, and the second refrigerant and the air blowing. A vehicle air conditioning system, comprising: a heater core (52) that heats air by exchanging heat with the radiator; and a radiator (50) that radiates heat of the second refrigerant. The vehicle air conditioning system according to claim 2,
In the heating operation, the compressor (42) is stopped and the inlet-side refrigerant pressure of the compressor (42) is stopped at a passenger compartment temperature at which the inlet-side refrigerant pressure of the compressor (42) may be less than atmospheric pressure. The vehicle air conditioning system, wherein the compressor (42) is driven when the temperature inside the passenger compartment reaches or exceeds atmospheric pressure. A vehicle air conditioning system according to claim 2 or claim 3,
In the heating operation and in the driving state of the compressor (42), the heating output of the heater (51) is controlled so as to compensate for the shortage of the heating capacity of the compressor (42). Air conditioning system. A vehicle air conditioning system according to claim 2 or claim 3,
In the heating operation and in the driving state of the compressor (42), the heating capacity of the heater (51) so that the outlet side refrigerant temperature of the heater core (52) is lower than the outlet side refrigerant temperature of the compressor (42). The air conditioning system for vehicles characterized by controlling. A vehicle air conditioning system according to any one of claims 2 to 5,
The second refrigerant is a liquid, and the condenser (43) is disposed in the second circulation path (48). It is an air conditioning system for vehicles in any one of Claims 2-6,
The vehicle air conditioning system, wherein the condenser (43) is provided in the second circulation passage (48), upstream of the heater (51) and downstream of the radiator (50). . It is an air conditioning system for vehicles in any one of Claims 2-7,
The vehicle air conditioning system, wherein the first refrigerant is carbon dioxide. It is an air conditioning system for vehicles in any one of Claims 1-8,
When the outlet side cold air temperature of the evaporator (46) is lower than the outside air temperature and the temperature difference is small, only a part of the cold air that has passed through the evaporator (46) is exhausted outside the passenger compartment, and other cold air is discharged. When the cold air temperature at the outlet side of the evaporator (46) is lower than the outside air temperature and the temperature difference is large, the cold air that has passed through the evaporator (46) is exhausted outside the vehicle interior. A vehicle air conditioning system characterized by the above.

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