A valve housing has a communication passage communicating a suction port of the compressor with a crank chamber of the compressor. A valve element opens and closes the communication passage, and a spring member resiliently biases the valve element toward the closed position. A pressure actuated unit moves the valve element toward the open position by a suction pressure of the compressor. The spring member includes a spring made of a temperature responsive material. The spring decreases in its resilient force in an opening direction of the valve element with increase of an outer-air temperature. The spring member has a primary spring made of an ordinary resilient material for resiliently biasing the valve element toward the closed position and a correction spring made of a material having a temperature positive characteristic. The correction spring provides a correction spring force smaller than a primary force of the primary spring in the opposite direction to the primary force. The combined spring force of the primary spring and the correction spring acting on the valve element.

Control valve for variable displacement compressor

A heat pump cycle includes a compressor having a suction port and a discharge port, a heating heat exchanger which heats air, a gas-liquid separator, and a cooling heat exchanger which cools air upstream of the heating heat exchanger in an air flow direction. The heat pump cycle further includes an intermediate pressure passage which guides gas refrigerant from the gas-liquid separator to the suction port. A variable open-close portion opens the intermediate pressure passage and decompresses the gas refrigerant in the intermediate pressure passage, so that the gas refrigerant is introduced into the suction port when a bypass dehumidifying-heating mode is selected as a dehumidifying-heating mode in which the air having been heated in the heating heat exchanger becomes equal to or higher than air in an air-conditioning target space in temperature.

Heat pump cycle

A refrigerating cycle device using carbon dioxide as refrigerant capable of solving such a problem that when a receiver is installed against a low pressure, a cost and a volume are increased by a pressure resistant design to assure safety, wherein a first pressure reducing device (12) and a second pressure reducing device (15) are operated to vary the refrigerant pressure of a first heat exchanger (13) so as to regulate the refrigerant hold amount of the first heat exchanger, whereby since the unbalance of the amount of refrigerant between cooling and heating/dehumidifying can be reduced, the refrigerating cycle device can be efficiently operated with a downsized receiver or without installing the receiver.

Refrigerating cycle device

A waste heat utilization device (2) for an internal combustion engine has a Rankine cycle (8) that recovers waste heat from an internal combustion engine (4), a generator (30) that is rotationally driven by an expander (14) and converts a rotational drive force into electric power, a converter (32) that controls the rotational speed of the expander (14) through the generator (30), refrigerant-condition detecting means (22, 24, 26, 28) that detects the pressure and temperature of a refrigerant passing through the expander (14), and a controller (34) that calculates pressure ratio Rp of the refrigerant in the immediate upstream and downstream of the expander (14) and specific heat ratio K of the refrigerant passing through the expander (14) on the basis of the pressure and temperature of the refrigerant, which have been detected by the refrigerant-condition detecting means (22, 24, 26, 28), calculates a preset pressure ratio Rps of the pressure ratio Rp by multiplying predetermined volume ratio Rv of the expander (14) by the specific heat ratio K, and specifies rotational speed N of the expander (14) to the converter (32) on the basis of the pressure ratio Rp and the preset pressure ratio Rps.

Waste Heat Utilization Device for Internal Combustion Engine

A control system for controlling a refrigeration system having an operating point, comprising: a memory configured to store a relationship of at least an evaporator efficiency, an evaporator heat load, a refrigerant amount in the evaporator, and a variable dependent on a non-volatile liquid mixed with refrigerant in the evaporator an input port configured to receive a signal corresponding to at least a measured evaporator heat load during operation; an output port configured to present an output to selectively alter an operating point of the evaporator, by altering the refrigerant amount in the evaporator and thereby changing the variable; and a processor, configured to receive the signal, access the memory; and generate the output to selectively move toward an optimum operating point. A corresponding method and refrigeration system are provided.

Method and apparatus for optimizing refrigeration systems

A vapor-compression refrigerant cycle system with a refrigeration cycle and a Rankine cycle includes a compressor, a radiator, a gas-liquid separator, a decompression device and an evaporator. In the vapor-compression refrigerant cycle system, a liquid pump is disposed for supplying the liquid refrigerant in the gas-liquid separator to a heater for heating the refrigerant, a cooling means is provided for cooling the liquid refrigerant to be sucked into the liquid pump, and an energy recovery unit for expanding the refrigerant flowing out of the heater is disposed to recover thermal energy in the refrigerant from the heater. When the Rankine cycle is set so that the energy recovery unit recovers the thermal energy, the cooling means cools the liquid refrigerant to be sucked into the liquid pump. Therefore, pumping efficiency of the liquid pump can be effectively improved.

Vapor-compression refrigerant cycle system with refrigeration cycle and rankine cycle

A waste heat collecting system for an internal combustion engine has an object to collect waste heat from the engine and make most use of the collected waste heat to achieve the maximum effect of improving fuel consumption ratio. The waste heat utilizing system has a waste heat collecting cycle for collecting waste heat from an internal combustion engine and having an expansion device for generating rotational driving force from the collected waste heat, a refrigerating cycle having a compressor device for compressing a refrigerant and a power transmitting means rotationally driven by a driving force generating means and operatively connected to the compressor device to rotationally drive the same. In this system, the expansion device is operatively connected to the compressor device to rotationally drive the same.

Waste heat utilizing system

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.

Refrigerant cycle system with expansion energy recovery

A heat pump cycle system which can switches cooling operation and heating operation for a compartment includes a first inside heat exchanger and a second inside heat exchanger disposed in an air conditioning case. The first inside heat exchanger is disposed in the air conditioning case at a downstream air side of the second inside heat exchanger, while being arranged in line in a flow direction of refrigerant. The first inside heat exchanger is upstream from the second inside heat exchanger in the flow direction of refrigerant during the heating operation. In the heat pump cycle system, an expansion valve is controlled so that coefficient of performance in each operation becomes approximately maximum. Thus, during the heating operation of the heat pump cycle system, a lower limit temperature of air blown from the inside heat exchangers can be increased so that temperature of air blown into the compartment is increased, while the coefficient of performance is improved.

Heat pump cycle system

PROBLEM TO BE SOLVED: To provide a refrigeration apparatus capable of avoiding pressure rise of a refrigerant in a high pressure side due to increase of refrigerant flow rate and simultaneously raising cooling capacity corresponding to the increase of the refrigerant flow rate. SOLUTION: A bypass passage B is provided for making part of a refrigerant flowing out of a refrigerant radiator 2 bypass an ejector 3 to flow into a gas- liquid separator 4. Control valves 7, 70 and 9 are provided in the halfway of the passage B. When the refrigerant flowing out of the radiator 2 comes to a specific pressure condition, the valves 7, 70 and 9 are opened to allow the refrigerant to flow into the passage B. Thus, the pressure of the refrigerant is surely prevented from being excessively raised, and a refrigeration cycle is stably operated. Further, even when the flow rate of the refrigerant increases, power for a refrigerant compressor 1 is prevented from increasing so that efficiency of the cycle is enhanced. Cooling capacity is raised corresponding to the increase of the refrigerant flow rate. COPYRIGHT: (C)2003,JPO

Tadashi Hotta

Papers

Vapor-compression refrigerant cycle system with refrigeration cycle and rankine cycle

Waste heat utilizing system

Refrigerant cycle system with expansion energy recovery

Heat pump cycle system

Refrigeration cycle apparatus