Heat pump cycle

Abstract

In a heat pump cycle, refrigerant tubes of an outdoor heat exchanger serving as an evaporator for evaporating refrigerant, and cooling fluid tubes of a radiator for dissipating heat from a coolant of an electric motor for traveling serving as an external heat source are bonded to the same outer fins. The heat contained in the coolant flowing through the cooling fluid tubes can be transferred to the refrigerant tubes of the outdoor heat exchanger via the outer fins. Thus, in the defrosting operation which involves defrosting the outdoor heat exchanger by flowing the coolant through the radiator, the loss in transfer of the heat contained in the coolant to the outdoor heat exchanger can be suppressed, and the heat supplied from the electric motor for traveling can be effectively used for defrosting the outdoor heat exchanger.

1 - 26 . (canceled) 
     
     
         27 . A heat pump cycle comprising:
 a compressor compressing and discharging refrigerant;   a user-side heat exchanger exchanging heat between the refrigerant discharged from the compressor and a heat exchange fluid;   a decompression device decompressing the refrigerant flowing from the user-side heat exchanger;   an outdoor heat exchanger which causes the refrigerant decompressed by the decompression device to exchange heat with outside air and to be evaporated, the heat pump cycle being adapted to perform a defrosting operation for defrosting the outdoor heat exchanger when the outdoor heat exchanger is frosted;   an indoor evaporator for allowing the refrigerant on a downstream side of the outdoor heat exchanger to exchange heat with the heat exchange fluid and to be evaporated;   a refrigerant flow path switching device configured to switch a refrigerant flow path in a heating operation in which the refrigerant discharged from the compressor flows into the user-side heat exchanger to heat the heat exchange fluid, and a refrigerant flow path in a cooling operation in which the refrigerant dissipating heat therefrom at the outdoor heat exchanger flows into the indoor evaporator to cool the heat exchange fluid,   a heat-dissipation heat exchanger, disposed in a cooling fluid circulation circuit for circulating a cooling fluid for cooling an external heat source, the heat-dissipation heat exchanger being adapted to exchange heat between the cooling fluid and the outside air; and   a cooling fluid circuit switching device configured to switch between a cooling fluid circuit for allowing the cooling fluid to flow into the heat-dissipation heat exchanger, and a cooling fluid circuit for allowing the cooling fluid to bypass the heat-dissipation heat exchanger, wherein   the outdoor heat exchanger includes a refrigerant tube in which the refrigerant decompressed by the decompression device flows,   a heat-absorption air passage for flowing the outside air is formed around the refrigerant tube,   the heat-dissipation heat exchanger includes a cooling fluid tube in which the cooling fluid flows,   a heat-dissipation air passage for flowing the outside air is formed around the cooling fluid tube,   the heat-absorption air passage and the heat-dissipation air passage are provided with an outer fin that enables heat transfer between the refrigerant tube and the cooling fluid tube, while promoting heat exchange in both of the outdoor heat exchanger and the heat-dissipation heat exchanger,   the cooling fluid circuit switching device performs switching to the cooling fluid circuit for flowing the cooling fluid into the heat-dissipation heat exchanger in at least the defrosting operation,   a flow direction of the refrigerant flowing through the refrigerant tube in the heating operation is the same as that of the refrigerant flowing through the refrigerant tube in the cooling operation,   a heat exchange region at a refrigerant inlet side of the outdoor heat exchanger is overlapped in an outside air flow direction with a heat exchange region at a cooling fluid inlet side of the heat dissipation heat exchanger,   the outdoor heat exchanger is configured, such that relatively high-temperature refrigerant flows through the heat exchange region at the refrigerant inlet side of the outdoor heat exchanger in the cooling operation, and relatively low-temperature refrigerant flows through the heat exchange region at the refrigerant inlet side of the outdoor heat exchanger in the heating operation, and   the heat dissipation heat exchanger is configured, such that relatively high-temperature cooling fluid flows through the heat exchange region at the refrigerant inlet side of the heat dissipation heat exchanger in both the cooling operation and the heating operation.   
     
     
         28 . The heat pump cycle according to  claim 27 , wherein in the defrosting operation, an inflow rate of the refrigerant flowing into the outdoor heat exchanger is decreased as compared to before transfer to the defrosting operation. 
     
     
         29 . The heat pump cycle according to  claim 27 , wherein
 the decompression device is a variable throttle mechanism in which a throttle opening degree is variable, and   the decompression device increases the throttle opening degree in the defrosting operation as compared to before transfer to the defrosting operation.   
     
     
         30 . The heat pump cycle according to  claim 27 , further comprising
 an outflow rate adjustment valve configured to adjust an outflow rate of the refrigerant flowing from the outdoor heat exchanger,   wherein the outflow rate adjustment valve decreases the outflow rate of the refrigerant in the defrosting operation as compared to before transfer to the defrosting operation.   
     
     
         31 . The heat pump cycle according to  claim 30 , wherein the outflow rate adjustment valve is configured integrally with an outlet for the refrigerant of the outdoor heat exchanger. 
     
     
         32 . The heat pump cycle according to  claim 27 , further comprising
 an outdoor blower which blows the outside air toward both the outdoor heat exchanger and the heat-dissipation heat exchanger,   wherein the outdoor blower increases an air blowing capacity when the compressor is stopped, as compared to before stopping the compressor.   
     
     
         33 . The heat pump cycle according to  claim 27 , wherein in the defrosting operation, a heating capacity of the user-side heat exchanger for heating the heat exchange fluid is decreased as compared to before transfer to the defrosting operation. 
     
     
         34 . The heat pump cycle according to  claim 27 , wherein the heat-absorption air passage and the heat-dissipation air passage are configured such that volumes of the outside air flowing into the heat-absorption air passage and the heat-dissipation air passage are decreased in the defrosting operation. 
     
     
         35 . The heat pump cycle according to  claim 27 , further comprising
 an outdoor blower which blows the outside air toward both the outdoor heat exchanger and the heat-dissipation heat exchanger,   wherein the heat-dissipation heat exchanger is located on a windward side in the flow direction of the outside air blown by the outdoor blower with respect to the outdoor heat exchanger.   
     
     
         36 . The heat pump cycle according to  claim 27 , wherein
 at least one of the refrigerant tubes is located between the cooling fluid tubes,   at least one of the cooling fluid tubes is located between the refrigerant tubes, and   at least one of the heat-absorption air passage and the heat-dissipation air passage is formed as one air passage.   
     
     
         37 . The heat pump cycle according to  claim 27  being applied to an air conditioner for a vehicle, the heat pump cycle further comprising:
 an inside air temperature detection portion configured to detect an inside air temperature of a vehicle interior; and 
 a frost formation determination portion configured to determine frost formation of the outdoor heat exchanger, wherein 
 the heat exchange fluid is air blown into the vehicle interior, 
 the external heat source is a vehicle-mounted device generating heat in operation, 
 the cooling fluid is a coolant for cooling the vehicle-mounted device, and 
 the cooling fluid circuit switching device performs switching to the cooling fluid circuit for flowing the cooling fluid into the heat-dissipation heat exchanger when the frost is determined to be formed at the outdoor heat exchanger by the frost formation determination portion and an inside air temperature of the vehicle interior is equal to or more than a predetermined reference inside air temperature. 
 
     
     
         38 . The heat pump cycle according to  claim 27  being applied to an air conditioner for a vehicle, the heat pump cycle further comprising
 a frost formation determination portion for determining frost formation of the outdoor heat exchanger, wherein 
 the heat exchange fluid is air blown into the vehicle interior, 
 the external heat source is a vehicle-mounted device generating heat in operation, 
 the cooling fluid is a coolant for cooling the vehicle-mounted device, 
 the user-side heat exchanger is disposed in a casing forming therein an air passage, 
 an inside/outside air switching device for changing a ratio of introduction of inside air to outside air to be introduced into the casing is disposed in the casing, wherein 
 the cooling fluid circuit switching device performs switching to the cooling fluid circuit for flowing the cooling fluid to the heat-dissipation heat exchanger when the frost is determined to be formed at the outdoor heat exchanger by the frost formation determination portion, and 
 the inside/outside air switching device increases the ratio of introduction of the inside air to the outside air as compared to before transfer to the defrosting operation when the frost is determined to be formed at the outdoor heat exchanger by the frost formation determination portion. 
 
     
     
         39 . The heat pump cycle according to  claim 27  being applied to an air conditioner for a vehicle, the heat pump cycle further comprising
 a frost formation determination portion configured to determine frost formation of the outdoor heat exchanger, wherein 
 the heat exchange fluid is air blown into the vehicle interior, 
 the external heat source is a vehicle-mounted device generating heat in operation, 
 the cooling fluid is a coolant for cooling the vehicle-mounted device, 
 the user-side heat exchanger is disposed in a casing forming therein an air passage, 
 an air outlet mode switching device for switching among air outlet modes by changing opening/closing states of air outlets for blowing the air into the vehicle interior is disposed in the casing, 
 at least a foot air outlet for blowing the air to a foot of a passenger is provided as the air outlet, 
 the cooling fluid circuit switching device performs switching to the cooling fluid circuit for flowing the cooling fluid into the heat-dissipation heat exchanger when the frost is determined to be formed at the outdoor heat exchanger by the frost formation determination portion, and 
 the air outlet mode switching device performs switching to the air outlet mode for blowing the air from the foot air outlet when the frost is determined to be formed at the outdoor heat exchanger by the frost formation determination portion. 
 
     
     
         40 . The heat pump cycle according to  claim 27  being applied to an air conditioner for a vehicle, the heat pump cycle further comprising
 a frost formation determination portion configured to determine frost formation of the outdoor heat exchanger, wherein 
 the heat exchange fluid is air blown into the vehicle interior, 
 the external heat source is a vehicle-mounted device generating heat in operation, 
 the cooling fluid is a coolant for cooling the vehicle-mounted device, 
 the user-side heat exchanger is disposed in a casing for forming therein an air passage, 
 a blower for blowing air toward the vehicle interior is disposed in the casing, 
 the cooling fluid circuit switching device performs switching to the cooling fluid circuit for flowing the cooling fluid into the heat-dissipation heat exchanger when the frost is determined to be formed at the outdoor heat exchanger by the frost formation determination portion, and 
 the blower decreases an air blowing capacity, as compared to before the determination of the frost formation. 
 
     
     
         41 . The heat pump cycle according to  claim 27  being applied to an air conditioner for a vehicle, the heat pump cycle further comprising
 a frost formation determination portion for determining frost formation of the outdoor heat exchanger, wherein 
 the heat exchange fluid is air blown into the vehicle interior, 
 the external heat source is a vehicle-mounted device generating heat in operation, 
 the cooling fluid is a coolant for cooling the vehicle-mounted device, 
 the frost formation determination portion determines that the frost is formed at the outdoor heat exchanger, when a vehicle speed is equal to or less than a predetermined reference speed, and when a temperature of the refrigerant on an outlet side of the outdoor heat exchanger is equal to or less than 0□□C, and 
 the cooling fluid circuit switching device performs switching to a cooling fluid circuit for flowing the cooling fluid into the heat-dissipation heat exchanger when the frost is determined to be formed at the outdoor heat exchanger by the frost formation determination portion. 
 
     
     
         42 . The heat pump cycle according to  claim 41 , wherein the frost formation determination portion determines that the frost is formed at the outdoor heat exchanger, when the speed of the traveling vehicle is equal to or less than the predetermined reference speed, and when the temperature of the refrigerant on the outlet side of the outdoor heat exchanger is equal to or less than 0□□C. 
     
     
         43 . The heat pump cycle according to  claim 37 , further comprising
 a coolant temperature detection portion configured to detect a temperature of the coolant flowing into a vehicle-mounted device,   wherein the cooling fluid circuit switching device performs switching to the cooling fluid circuit for flowing the cooling fluid into the heat-dissipation heat exchanger when a coolant temperature detected by the coolant temperature detection portion is equal to or more than the predetermined reference temperature.   
     
     
         44 . The heat pump cycle according to  claim 27 , wherein the cooling fluid circulation circuit stores therein the heat contained in the external heat source when the cooling fluid circuit switching device performs switching to the cooling fluid circuit for allowing the cooling fluid to bypass the heat-dissipation heat exchanger. 
     
     
         45 . The heat pump cycle according to  claim 44  being applied to an air conditioner for a vehicle, wherein
 the heat exchange fluid is air blown into the vehicle interior, 
 the external heat source is a vehicle-mounted device generating heat in operation, 
 the cooling fluid is a coolant for cooling the vehicle-mounted device, and 
 the cooling fluid circulation circuit stores heat dissipated from the vehicle-mounted device in the coolant when the cooling fluid circuit switching device performs switching to the cooling fluid circuit for allowing the cooling fluid to bypass the heat-dissipation heat exchanger. 
 
     
     
         46 . The heat pump cycle according to  claim 44  being applied to an air conditioner for a vehicle, wherein
 the heat exchange fluid is air blown into the vehicle interior, 
 the external heat source is a heating element for generating heat by being supplied with power, 
 the cooling fluid is a coolant for cooling the heating element, and 
 the cooling fluid circulation circuit stores the heat dissipated from the heating element in the coolant when the cooling fluid circuit switching device performs switching to the cooling fluid circuit for allowing the cooling fluid to bypass the heat-dissipation heat exchanger. 
 
     
     
         47 . The heat pump cycle according to  claim 44  being applied to an air conditioner for a vehicle, wherein
 the heat exchange fluid is air blown into the vehicle interior, 
 a vehicle-mounted device generating heat in operation, and a heating element for generating heat by being supplied with power are provided as the external heat source, 
 the cooling fluid is a coolant for cooling the heating element and the vehicle-mounted device, and 
 the cooling fluid circulation circuit stores the heat dissipated from at least one of the vehicle-mounted device and the heating element in the coolant when the cooling fluid circuit switching device performs switching to the cooling fluid circuit for allowing the cooling fluid to bypass the heat-dissipation heat exchanger. 
 
     
     
         48 . The heat pump cycle according to  claim 46 , wherein the heating element has an amount of generated heat therefrom controlled based on an outside air temperature. 
     
     
         49 . The heat pump cycle according to  claim 27 , further comprising:
 an outdoor unit bypass passage which causes the refrigerant decompressed by the decompression device to bypass the outdoor heat exchanger and to guide the refrigerant to a refrigerant outlet side of the outdoor heat exchanger; and   an outdoor-unit bypass passage switching device configured to switch between a refrigerant circuit for guiding the refrigerant decompressed by the decompression device to the outdoor heat exchanger, and a refrigerant circuit for guiding the refrigerant decompressed by the decompression device toward the outdoor unit bypass passage,   wherein in the defrosting operation, the outdoor unit bypass passage switching device performs switching to the refrigerant circuit for guiding the refrigerant decompressed by the decompression device to the outdoor unit bypass passage.   
     
     
         50 . The heat pump cycle according to  claim 27 , further comprising:
 an indoor evaporator which exchanges heat between the refrigerant on a downstream side of the outdoor heat exchanger and the heat exchange fluid;   an evaporator bypass passage which causes the refrigerant on the downstream side of the outdoor heat exchanger to bypass the indoor evaporator and to guide the refrigerant to a refrigerant outlet of the indoor evaporator; and   an evaporator bypass passage switching device configured to switch a refrigerant circuit for guiding the refrigerant on the downstream side of the outdoor heat exchanger to the indoor evaporator, and a refrigerant circuit for guiding the refrigerant on the downstream side of the outdoor heat exchanger to the evaporator bypass passage,   wherein in the defrosting operation, the evaporator bypass passage switching device performs switching to the refrigerant circuit for guiding the refrigerant on the downstream side of the outdoor heat exchanger to the indoor evaporator.   
     
     
         51 . The heat pump cycle according to  claim 27  being applied to an air conditioner for a vehicle, wherein
 the heat exchange fluid is air blown into the vehicle interior,
 the user-side heat exchanger is disposed in a casing for forming therein an air blowing passage, and 
 in the casing, an auxiliary heater is provided for heating the air blown into the vehicle interior using as a heating source, at least one of a heating fluid heated by a vehicle-mounted device that generates heat in operation, and a heating element that generates heat by being supplied with power.