Gas, injection, piston, technology, temperature, reduction
Gas vapor injection on refrigerant cycle is always used with Scroll, Rotary or others compressors technology to improve efficiency of the system at low and high ambient temperatures. Probably this kind of compressor is more adapted than the piston technology owing to their mechanical system. In this paper, we present the challenge of vapor injection realized on piston technology compressor range non for improving the cooling capacity of the system but to maintain the compressor temperature in conformity without damage the capacity. Indeed, the principal action of gas injection is to refresh the mechanical system according to the ambient temperature for improving the capacity of the system. In this case of study, the compressor is enclosure on a room without opening at the ambient, thus the temperature of the compressor exceed 130°C, which is the limit temperature of compressor functioning. To reduce the compressor temperature on this refrigerant cycle a gas injection is done from output of condenser to the input of the compressor thanks to the capillary tubes. Therefore, the quantity of gas injection must be sufficient to reduce the temperature, and not damage the capacity of the system. In addition, the piston technology compressor is more sensitive than the others compressors technologies because the compressor valve behavior could be damaged by the liquid phase of the refrigerant. That why the capillary tubes and the density of gas are defined by simulation and the results have been comforted by test. Thus, thanks to gas injection, we can reduce the temperature of the compressor on the refrigerant system with only a capillary tube.