Stopping method and system for low temperature unit, low temperature unit and refrigerating system

Abstract

The invention discloses a stopping method and system for a low temperature unit, the low temperature unit and a refrigerating system. The stopping method for the low temperature unit comprises the steps of carrying out low pressure control over the low temperature unit to enable the low pressure of the low temperature unit to reach the preset stable threshold value; carrying out pumping-out circulation on the low temperature unit when the low pressure of the low temperature unit reaches the preset stable threshold value, and carrying out low pressure protection shielding to achieve stopping control and to enable the low temperature unit to meet the preset stopping condition and reliably stop when pumping-out circulation is carried out on the low temperature unit. According to the scheme, the shortcomings that the pressure control accuracy is low, the system operation safety is poor and the abnormal failure rate is high in the prior art can be overcome, and the stopping method and system have the advantages that the pressure control accuracy is high, the system operation safety is high and the abnormal failure rate is low.

Description

technical field [0001] The invention relates to the technical field of low temperature control, in particular to a method and system for shutting down a low temperature unit, a low temperature unit and a refrigeration system. Background technique [0002] At present, the lowest evaporation temperature of low-temperature condensing units on the market is generally around -35°C. Therefore, for most cold storage shutdown methods, there are two main types: [0003] The first shutdown mode: when the target storage temperature reaches the requirement, the refrigeration system will be shut down directly; Figure 8 example shown. [0004] The second shutdown method: the target storage temperature reaches the requirement, and the refrigeration system is shut down by pumping down. [0005] For the first shutdown mode, the incompletely evaporated refrigerant liquid in the evaporator in the refrigeration system will migrate to the inside of the compressor after shutdown, which will ea...

AI Technical Summary

Problems solved by technology

[0008] In the existing technology, there are defects such as poor pressure control accuracy, poor system operation safety and high abnormal failure rate

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