Patent ID: 7841195

Claim:
A refrigeration apparatus comprising: a condensing unit; a flow distributor; an expansion valve; an evaporator connected to said condensing unit via said flow distributor; a pressure detector configured to detect condensation pressure of the refrigerant, said pressure detector being located upstream of said expansion value and downstream of said condensing unit; a refrigerant liquid receiver provided downstream of said condensing unit and upstream of said pressure detector; a calculation unit configured to calculate a target condensation pressure of the refrigerant necessary for the refrigerant to be an evaporation temperature in the evaporator; and a controller configured to control said condensing unit so that the condensation pressure of the refrigerant becomes equal to or more than the target condensation pressure, wherein said condensing unit includes an adjustable valve at an output side of said condensing unit to control the flow of the refrigerant, wherein said adjustable valve is provided downstream of said condensing unit and upstream of said expansion valve, and wherein said controller is configured to control the adjustable valve; and wherein said calculation unit is configured to calculate the target condensation pressure according to the following equation: target condensation pressure=1125.08+(9.07965 *X )+(−0.101693 *X*X )+(40.8041 *Y )+(1.60973 *X*Y )+(0.0177658 *X*X*Y )+(−0.0547654 *Y*Y )+(−0.00318583 *X*Y*Y )+(−0.000044704 *X*X*Y*Y ), where X is the evaporation temperature, and Y is the liquid refrigerant temperature.