Abstract: When the first pressure reducing device 161 is fixed to the accumulator tank 140 and the internal heat exchanger 150 is housed in the accumulator tank 140, the accumulator, the first pressure reducing device 161 and the internal heat exchanger 150 are integrated into one body. Due to the foregoing, it is possible to eliminate parts for piping to connect the first pressure reducing device 161 with the internal heat exchanger 150. The mass of the vibration system of the first pressure reducing device 161 including the accumulator tank 140 and the internal heat exchanger 150 is increased. Therefore, even if the valve body 413 in the first pressure reducing device is vibrated, it becomes difficult for other portions to vibrate. Accordingly, it is possible to reduce noise (vibration) generated when refrigerant is decompressed by the first pressure reducing device 161.

Abstract: An automotive climate control system is disclosed. As long as an ignition switch is off, a bypass (14) is closed (in this state, a ratio between warm air and cool air is a maximum when the automotive climate control system is activated.), the blowout is set to defrost mode and the introduced air is set to external air mode regardless of the preceding modes of blowout and introduced air (when the ignition switch is on). As a result, the refrigerant leaking from an evaporator (12) flows to an external air inlet (23) smaller in air resistance. Even in the case where the ignition switch is off, therefore, the leaking refrigerant is prevented from flowing into the cabin.

Abstract: In a vehicle air conditioner having a refrigerant cycle using carbon dioxide as refrigerant, a displacement of a compressor is changed and controlled, so that an air temperature immediately after passing through an evaporator becomes approximately 0° C., and it can prevent a refrigerant amount discharged from the compressor from being larger than a predetermined flow amount. Because the refrigerant amount discharged from the compressor is controlled to be not larger than the predetermined flow amount, it can prevent a high-pressure side refrigerant pressure and a high-pressure side refrigerant temperature from being excessively increased in the refrigerant cycle.

Abstract: In a refrigerant cycle system, refrigerant compressed in a first compressor is cooled and condensed in a radiator, and refrigerant from the radiator branches into main-flow refrigerant and supplementary-flow refrigerant. The main-flow refrigerant is decompressed in an expansion unit while expansion energy of the main-flow refrigerant is converted to mechanical energy. Thus, the enthalpy of the main-flow refrigerant is reduced along an isentropic curve. Therefore, even when the pressure within the evaporator increases, refrigerating effect is prevented from being greatly reduced in the refrigerant cycle system. Further, refrigerant flowing into the radiator is compressed using the converted mechanical energy. Thus, coefficient of performance of the refrigerant cycle system is improved.

Abstract: In a refrigerant cycle system, refrigerant compressed in a first compressor is cooled and condensed in a radiator, and refrigerant from the radiator branches into main-flow refrigerant and supplementary-flow refrigerant. The main-flow refrigerant is decompressed in an expansion unit while expansion energy of the main-flow refrigerant is converted to mechanical energy. Thus, the enthalpy of the main-flow refrigerant is reduced along an isentropic curve. Therefore, even when the pressure within the evaporator increases, refrigerating effect is prevented from being greatly reduced in the refrigerant cycle system. Further, refrigerant flowing into the radiator is compressed using the converted mechanical energy. Thus, coefficient of performance of the refrigerant cycle system is improved.

Abstract: An automotive climate control system is disclosed. As long as an ignition switch is off, a bypass (14) is closed (in this state, a ratio between warm air and cool air is a maximum when the automotive climate control system is activated.), the blowout is set to defrost mode and the introduced air is set to external air mode regardless of the preceding modes of blowout and introduced air (when the ignition switch is on). As a result, the refrigerant leaking from an evaporator (12) flows to an external air inlet (23) smaller in air resistance. Even in the case where the ignition switch is off, therefore, the leaking refrigerant is prevented from flowing into the cabin.

Abstract: When a compressor is stopped, a refrigerant passage in which refrigerant flows from a radiator to an evaporator is closed by a pressure control valve. Accordingly, even after the compressor is stopped, a high-pressure side pressure can be prevented from decreasing. This does not cause increased manufacturing cost of a supercritical refrigerating system.

Abstract: The supercritical refrigerating apparatus has refrigerant bypass means for bypassing a heat exchanger according to a physical value of the refrigerant. Therefore, the temperature of refrigerant on a suction side of the compressor becomes lower than that of refrigerant sucked into the compressor via the heat exchanger. As a result, the refrigerant temperature in a refrigerant passage extending from a suction side to a discharge side of the compressor is decreased, thereby preventing breakage of the compressor.

Abstract: In a CO.sub.2 refrigerant cycle, a lubricating oil for a compressor has a compatibility relative to CO.sub.2 refrigerant, and the compatibility of the lubricating oil relative to the CO.sub.2 refrigerant at a pressure lower than a critical pressure of the CO.sub.2 refrigerant is lower than that at a pressure higher than the critical pressure of the CO.sub.2 refrigerant. Thus, in a low-pressure side such as an accumulator of the CO.sub.2 refrigerant cycle, because a liquid lubricating oil is separated with a liquid CO.sub.2 refrigerant, only the lubricating oil can be readily introduced into a suction side of the compressor, and it can prevent the liquid CO.sub.2 refrigerant from being sucked into the compressor. As a result, it can prevent a damage to the compressor while preventing deterioration of coefficient of performance of the CO.sub.2 refrigerant cycle.

Abstract: An air conditioning system having an evaporator 8 at a location upstream from a compressor. When a compressor is stopped, a refrigerant inlet is closed by an electromagnetic valve 28 and a refrigerant outlet is closed by a check valve 29. A pressure in the closed passageway is detected by a pressure sensor 22. A leakage of refrigerant at the evaporator is reliably detected, which allows the leakage of the refrigerant to be quickly noticed.

Abstract: A thermal expansion valve for automotive coolant systems which is significantly more compact than previously developed expansion values. The housing of the expansion valve is divided into a first housing formed in a cylindrical shape with a bottom and a second housing formed in a columnar shape. The first housing is fit into the second housing, and both are integrally connected to each other. A temperature sensing mechanism having a temperature sensing chamber and an expansion mechanism for adjusting an opening degree of a throttle passage in accordance with an evaporator outlet temperature sensed by the temperature sensing means are disposed in the second housing. First and fourth joint portions connected to inlet and outlet refrigerant pipes of the evaporator, respectively, are at the bottom of the first housing.