First; Copeland digital compressor 6SHH-3500 US Copeland fully enclosed digital scroll refrigerator features and structure
A special type of other adjustment methods is a digital scroll compressor, which also uses the principle of suction backflow to regulate the refrigeration capacity of the compressor.
This scroll compressor has an axial floating characteristic, and the two scrolls are tightly fitted together in the axial direction by the gas pressure behind the stationary plate, keeping the gas sealed to compress the gas. After the gas back pressure is lost, the driving force for bringing the scrolls together is lost, the two scrolls are disengaged, a large axial gap occurs, and the inhaled gas will be unable to be compressed due to internal leakage, the compressor The amount of gas delivered is basically zero.
This produces the basic principle of the digital scroll compressor to adjust the cooling capacity: artificially control the gas pressure behind the static plate, the two scrolls are disengaged, and the inhaled gas is returned to the larger axial gap between the scrolls. At the suction port, the compressor remains idling but has no exhaust, and the cooling capacity is zero. The "load state" corresponding to the normal operation of the compressor may be referred to as "unloading state" at this time.
The back pressure is controlled by an electronic valve. When the electronic valve is closed, the compressor is under load and works normally with a cooling capacity of 100%. When the electronic valve is opened, the back pressure is reduced, the compressor is unloaded, and the cooling capacity is zero. In this sense, this adjustment mode has the characteristics of on-off regulation. The big difference is that the compressor does not stop, so there is no court loss, but the compressor will consume a certain amount of energy when it is idling. According to the foregoing discussion of the start-stop regulation, it is easy to understand that the control should ensure that the unloading time should not be too long, otherwise the cooling system will have extra energy loss after high and low pressure balance. By controlling the time ratio of the load state and the unloading state, different cooling capacities can be obtained, thereby achieving the purpose of cooling capacity adjustment.
The digital vortex adjustment method does not require a variable frequency controller, and there are no various disadvantages of the frequency conversion adjustment, but the adjustment range is relatively large and can only reach 100%. In addition, the solenoid valve that controls the back pressure is a critical component, and the effectiveness of the solenoid valve will directly lead to the failure of the compressor.ZPI292KCE-TWD-522，ZP295KCE-TWD-522，ZP385KCE-TWD-522