A heat pump system includes a first bypass pipe provided with a first bypass valve and connecting a liquid refrigerant pipe and a low-pressure refrigerant pipe, a refrigerant heat exchanger configured to cause a heat-exchange between refrigerant flowing in the liquid refrigerant pipe and refrigerant flowing in first bypass pipe, a second bypass pipe provided with a second bypass valve and connecting the liquid refrigerant pipe and the low-pressure refrigerant pipe, and a controller. The controller is configured to control opening degree of the first bypass valve based on detected superheated temperature of refrigerant flowing in the first bypass pipe, and detected discharge temperature of a compressor and control opening degree of the second bypass valve based on the detected discharge temperature.

A compressor includes a cylinder block having a first bore and a cylinder head overlapping the cylinder block. The cylinder head has a second bore aligned with the first bore. The second bore is separated into a plurality of distinct regions including a suction region and an economizer region. A plurality of valves includes a suction valve selectively operable to fluidly couple the suction region and the first bore, and an economizer valve selectively operable to fluidly couple the economizer region and the first bore.

A header includes a plurality of branch tubes and a header manifold. If refrigerant flowing into the header manifold forms a pattern of annular flow or churn flow, tips of the branch tubes inserted into the header manifold pass through a liquid-phase portion having a thickness δ [m] and reach a gas-phase portion. The thickness δ [m] of the liquid-phase portion is defined as δ=G×(1−x)×D/(4ρ.sub.L×U.sub.LS), where G is a flow speed [kg/(m.sup.2 s)] of the refrigerant, x is a quality of the refrigerant, D is an inside diameter [m] of the header manifold, ρ.sub.L is a liquid density [kg/m.sup.3] of the refrigerant, U.sub.LS is a reference apparent liquid speed [m/s] that is a maximum value within a range of variation in an apparent gas speed of the refrigerant flowing into a flow space of the header manifold. The reference apparent liquid speed U.sub.LS [m/s] is defined as G(1−x)/ρ.sub.L.

A test chamber and a method for conditioning air in a temperature-insulated test space of a test chamber, which is sealable against an environment and serves for receiving test material, a temperature ranging from −20° C. to +180° C. being produced within the test space by means of a cooling device of a temperature control device of the test chamber, using a cooling circuit with carbon dioxide (CO.sub.2) as a cooling agent, using a heat exchanger in the test space, using a low-pressure compressor and using a high-pressure compressor downstream of the low-pressure compressor, using a gas cooler, using a storage means for the cooling agent and using an expansion valve, the temperature in the test space being controlled and/or regulated by means of a control device of the test chamber. A gaseous and/or liquid cooling agent is dosed in the storage means by means of a high-pressure valve of the cooling circuit downstream of the gas cooler, the storage means being connected to a medium-pressure side of the cooling circuit upstream of the high-pressure compressor and downstream of the low-pressure compressor via a medium-pressure bypass of the cooling circuit, the gaseous cooling agent being dosed in the medium-pressure side from the storage means by means of a medium-pressure valve when the low-pressure compressor is switched off.

A first intermediate plate and a second intermediate plate are supported by a bottom member through a plurality of second elastic members. The first compressor and the second compressor are supported by the first intermediate plate and the second intermediate plate, respectively, through a plurality of first elastic members.

A refrigeration cycle apparatus includes; a refrigerant circuit in which a compressor, a heat-source-side heat exchanger, a first expansion device, a second expansion device, and a load-side heat exchanger are sequentially connected by refrigerant pipes and in which refrigerant is circulated; a controller that controls the refrigerant circuit; a bypass pipe extending from a liquid pipe between the first expansion device and the second expansion device toward a suction side of the compressor; a third expansion device provided at the bypass pipe to decompress the refrigerant that flows through the bypass pipe; and a refrigerant cooler provided at the bypass pipe and downstream of the third expansion device to cause heat exchange to be performed between the refrigerant decompressed by the third expansion device and heat generated from the controller.

This disclosure relates to cold-chain transportation, and more particularly to a refrigerated container refrigeration system capable of preventing freezing of container door, including compressors, oil separators, gas coolers, regenerators, electronic expansion valves, gas-liquid separators, an evaporator, suction pressure regulating valves, oil-level solenoid valves, gas cooler pressure regulating valves, differential pressure regulating valves, an evaporation pressure regulating valve, solenoid valves, check valves, flow meters, pressure sensors, temperature sensors, a door anti-freezing area, a refrigerated container shell, refrigerated container doors, a refrigeration unit, an anti-freezing pipeline and fastening components. Carbon dioxide is selected as refrigerant. A flow two-stage cycle compression refrigeration system with switchable operation pipeline is adopted, and the outlet pipeline of a high-pressure compressor is extended for preventing freezing of container door.

The present invention relates to an air conditioner. In an air conditioner according to an embodiment, a scroll compressor having a refrigerating capacity of 23 kW to 58 kW and an amount of circulating refrigerant of 880 cc is used, a refrigerant mixture containing 50% or more of R32 is used as a refrigerant circulating the air conditioner, and a flexible stainless steel pipe having 1% or less of delta ferrite matrix structure on the basis of the grain size area is comprised in a refrigerant pipe. Therefore, the strength and hardness of the refrigerant pipe is maintained to be equal to or higher than those of a copper pipe, and the processability can be well maintained.

An air conditioning system can be toggled between a heating mode, in which heat is withdrawn from a source (e.g., a geothermal source) and deposited into a conditioned space (e.g., a building), and a cooling mode, in which heat is withdrawn from the conditioned space and deposited into the source. The air conditioning system uses a combination of efficiency-enhancing technologies, including injection of superheated vapor into the system's compressor from an economizer circuit, adjustable compressor speed, the use of one or coaxial heat exchangers and the use of electronic expansion valves that are continuously adjustable from a fully closed to various open positions. A controller may be used to control the system for optimal performance in both the heating and cooling modes, such as by disabling the economizer circuit and vapor injection when the system is in the cooling mode.

The present invention relates to a refrigerant composition comprising at least about 98.5% by weight of the following three compounds, with each compound being present in the following relative percentages: 33.0% to 45% by weight difluoromethane (HFC-32); 48.5% to 67.0% by weight of 2,3,3,3-tetrafluoropropene (HFO-1234yf); and 1.0% to 6.0% by weight fluoroethane (HFC-161), and to the use of the refrigerant in a heat exchange system, including air conditioning, refrigeration applications and heat pump applications and to the use of such compositions as a replacement of the refrigerant R-410A or R-32 or R-454B for heating and cooling applications.