Abstract: A refrigeration cycle apparatus is mounted in a vehicle and has a circulation circuit through which a refrigerant circulates. The apparatus includes a refrigerant amount calculating unit and an operating state determining unit. The refrigerant amount calculating unit acquires a physical quantity and calculates an amount of the refrigerant. The operating state determining unit determines, based on traveling conditions of the vehicle, whether the vehicle is in an operating state in which the refrigerant circulating in the circulation circuit becomes a stable state. The refrigerant amount calculating unit calculates the amount of the refrigerant when the operating state determining unit determines that the vehicle is in the operation state.

Abstract: A multi-stage compression refrigeration cycle device includes a controller that controls rotational speeds of a low-stage side compression mechanism and a high-stage side compression mechanism, and a physical quantity sensor that detects a physical quantity correlated with a pressure of a low-pressure refrigerant. The controller is configured to increase a rotational speed ratio of the rotational speed of the low-stage side compression mechanism to the rotational speed of the high-stage side compression mechanism as the pressure of the low-pressure refrigerant becomes higher, based on the physical amount detected by the physical quantity sensor.

Abstract: An air-conditioner is operated under one mode selected from among three modes, i.e., a cooling mode, a heating mode and an air-mixing mode. Conditioned air temperature is controlled by changing a cooling ability in the cooling mode, a heating ability in the heating mode, and a position of an air-mixing door in the air-mixing mode. When the operating mode is switched to the cooling mode or to the heating mode from another mode, the position of the air-mixing door is gradually changed to prevent an abrupt temperature drop or rise until a difference between a target temperature and an actual temperature becomes smaller than a predetermined value.

Abstract: A power supply control for a vehicle includes air-conditioning electric devices and other electric devices. In the power supply control operation, current target power that is necessary for the specific electric device is calculated based on a precedent target power that was calculated the last time the specific electric device was used. An allowed power that is allowed to be supplied to the specific electric device is calculated based on the total power demand of the vehicle. The power to be supplied to the specific device is limited to the allowed power if the current target power is larger than the allowed power and the precedent target power is replaced with the allowed power if the actual power supplied to the specific electric device is limited to the allowed power.

Abstract: In a fluid heating apparatus, a heat protect temperature sensor indirectly detects temperature of fluid heated by an electric heater adjacent to the electric heater. Also, a heated fluid sensor detects the temperature of the fluid adjacent to a fluid inlet of a heat exchanger. When it is determined that the temperature difference between the detected temperatures exceeds a predetermined level, electric power supply to the electric heater is discontinued. Thus, boil-dry is restricted early with a simple means.

Abstract: An air-conditioner is operated under one mode selected from among three modes, i.e., a cooling mode, a heating mode and an air-mixing mode. Conditioned air temperature is controlled by changing a cooling ability in the cooling mode, a heating ability in the heating mode, and a position of an air-mixing door in the air-mixing mode. When the operating mode is switched to the cooling mode or to the heating mode from another mode, the position of the air-mixing door is gradually changed to prevent an abrupt temperature drop or rise until a difference between a target temperature and an actual temperature becomes smaller than a predetermined value.

Abstract: In a fluid heating apparatus, a heat protect temperature sensor indirectly detects temperature of fluid heated by an electric heater adjacent to the electric heater. Also, a heated fluid sensor detects the temperature of the fluid adjacent to a fluid inlet of a heat exchanger. When it is determined that the temperature difference between the detected temperatures exceeds a predetermined level, electric power supply to the electric heater is discontinued. Thus, boil-dry is restricted early with a simple means.

Abstract: In a vehicle air-conditioning system, a supply of electric power to a first electric heater and a supply of electric power to a second electric heater are duty controlled at the same duty ratio in such a manner that the supply of the electric power to the second electric heater is phase shifted by one half of a period from the supply of the electric power to the first electric heater.

Abstract: In an air conditioner for a vehicle having a temperature-controlled apparatus such as a fuel cell system, a heater core heats air by using unnecessary thermal energy from the fuel cell system. Further, a switching valve is controlled to switch between a first circuit and a second circuit. Cooling water is circulated between the heater core and the fuel cell system in the first circuit, and passes through the heater core while by passing the fuel cell system in the second circuit. When a cooling water temperature flowing from the heater core is lower than a cooling water temperature from the fuel cell system, the switching valve is controlled by a control unit to select the first circuit. Accordingly, the heater core can effectively use the unnecessary thermal energy from the fuel cell system.

Abstract: A vehicle air-conditioning system limits electric power used by an electric motor for a compressor in a prescribed fashion that quickly removes fog from the windows when a defroster mode is selected. When the defroster mode is selected, the limit on the electric power used by the electric motor is lifted, and the number of revolutions of the compressor is set to a high level to raise the dehumidifying and cooling capability to quickly remove moisture from the windows.

Abstract: An air-conditioner for use in an electric vehicle or a hybrid vehicle includes an electric heater for heating water circulating through a heater core and a compressor for compressing refrigerant in a refrigeration cycle. The electric heater is powered by an on-board battery, and the compressor is also driven by the same on-board battery. When a voltage of the on-board battery abnormally increases to a first predetermined level, the electric heater is switched off to prevent the electric heater from being overheated. When the voltage further increases to a second predetermined level, operation of the compressor is also terminated. Thus, the electric heater is properly protected from the abnormally high voltage while properly keeping performance of the air-conditioner.

Abstract: A power supply control apparatus is provided for a vehicle that includes air-conditioning electric devices and other electric devices. In the power supply control operation, current target power that is necessary for the specific electric device is calculated based on precedent target power calculated last time; allowed power that is allowed to be supplied to a specific electric device is calculated based on total power demand of the vehicle; power to be supplied to the specific device to the allowed power if the current target power is larger than the allowed power; and the precedent target power is replaced with the allowed power if actual power supplied to the specific electric device is limited to the allowed power.

Abstract: A vehicle air-conditioning system limits electric power used by an electric motor for a compressor in a prescribed fashion that quickly removes fog from the windows when a defroster mode is selected. When the defroster mode is selected, the limit on the electric power used by the electric motor is lifted, and the number of revolutions of the compressor is set to a high level to raise the dehumidifying and cooling capability to quickly remove moisture from the windows.

Abstract: In an air conditioner for a hybrid vehicle, when a residual charging degree of a battery becomes equal to or lower than a target degree, the electrical motor generator is driven by a vehicle engine so that the battery is charged through the electrical motor generator. When the engine is driven, the target degree of the battery is set higher than that when the engine is stopped so that a charging operation tends to be required while the engines driven. Accordingly, the frequency for starting the engine only for charging the battery is reduced.

Abstract: An air-conditioner for use in an electric vehicle or a hybrid vehicle includes an electric heater for heating water circulating through a heater core and a compressor for compressing refrigerant in a refrigeration cycle. The electric heater is powered by an on-board battery, and the compressor is also driven by the same on-board battery. When a voltage of the on-board battery abnormally increases to a first predetermined level, the electric heater is switched off to prevent the electric heater from being overheated. When the voltage further increases to a second predetermined level, operation of the compressor is also terminated. Thus, the electric heater is properly protected from the abnormally high voltage while properly keeping performance of the air-conditioner.

Abstract: An automotive air-conditioner operates under three modes: a face mode in which cool air is blown toward a passenger's face, a foot mode in which hot air is blown toward passenger's feet, and a bilevel mode in which the cool air and the hot air are blown to the face and the feet, respectively. Under the bilevel mode, either a cooling ability or a heating ability of the air-conditioner, or both, are increased, compared with those under the face mode and the foot mode. Thus, a temperature difference between air supplied to the face and air supplied to the feet becomes large, thereby providing the passenger with an improved feeling of air-conditioning.

Abstract: In a vehicle air conditioner where air blown into a passenger compartment is heated in a heater core using cooling water for cooling a fuel cell system as a heating source, a flow amount of cooling water flowing into the heat core is controlled by a control valve based on a surplus heat quantity of the fuel cell system and a necessary heat quantity of the passenger compartment. Further, when the surplus heat quantity of the fuel cell system is smaller than the necessary heat quantity, an insufficient heat quantity is supplemented by a supplementary heater.

Abstract: In a vehicle air-conditioning system, a supply of electric power to a first electric heater and a supply of electric power to a second electric heater are duty controlled at the same duty ratio in such a manner that the supply of the electric power to the second electric heater is phase shifted by one half of a period from the supply of the electric power to the first electric heater.

Abstract: In an air conditioner for a hybrid vehicle, when a residual charging degree of a battery becomes equal to or lower than a target degree, the electrical motor generator is driven by a vehicle engine so that the battery is charged through the electrical motor generator. When the engine is driven, the target degree of the battery is set higher than that when the engine is stopped so that a charging operation tends to be required while the engine is driven. Accordingly, the frequency for starting the engine only for charging the battery is reduced.

Abstract: A temperature sensor detecting a temperature of fluid flowing through a fluid passage is disposed at a bent portion located at an upper side of the fluid passage in an area close to a fluid outlet. Particularly, the temperature sensor is disposed at a position far from the fluid inlet by half or more of an entire length L of the fluid passage. Thus, it is possible to prevent the detected temperature of the temperature sensor from being remarkably different from an actual temperature and to prevent the electric heater from being thermally damaged.