JPH0320284U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a refrigeration system according to an embodiment of this invention, Fig. 2 is a block diagram of a conventional refrigeration system, Fig. 3 is a region determination diagram of low pressure side pressure, and Fig. 4 is a diagram of capacity control operation. It is an explanatory diagram. In these figures, 1a, 1b, 1c are compressors, 4 is a condenser, 7 is an evaporator, 5 is a solenoid valve, 8 is a pressure setting section, 9 is a comparison section, 10 is a pressure detection sensor, and 17 is an off cycle Defrost starting device, 1
8 is a control unit, and 20 is an aperture device. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A refrigerant circuit composed of a compressor, a condenser, a throttle device, and an evaporator that enable capacity control operation by controlling the number of units or using an inverter, an off-cycle defrost starting device that generates an off-cycle defrost signal, and the above-mentioned refrigerant circuit. A solenoid valve that is provided in the liquid pipe that communicates the condenser and the throttle device and closes in response to the off-cycle defrost signal, a pressure detection sensor that detects the pressure on the low pressure side of the refrigerant circuit, and a pressure detection sensor that increases the operating capacity of the compressor. a pressure setting unit for setting each pressure value, operating capacity down value, and low pressure cut value, and an output signal from the pressure detection sensor and the above operating capacity up value, operating capacity down value, and low pressure cut value set in advance. and a comparison section that compares the operating capacity of the compressor based on the output signal from the comparison section.After the solenoid valve is closed by the off-cycle defrost signal, the low-pressure side pressure of the refrigerant circuit is determined. Control that maximizes the capacity of the compressor until the low pressure cut value is reached, and after the low pressure side pressure reaches the low pressure cut value, completely stops the compressor until the off cycle defrost signal is released. A capacity-controlled refrigeration device characterized by comprising: