Low voltage protection method for rail vehicle air conditioner

Abstract

The invention discloses a low-pressure protection method for rail vehicle air conditioners, which belongs to the technical field of rail vehicle air-conditioning equipment, and is based on an air-conditioning unit having a low-pressure pressure switch and a bypass solenoid valve, wherein the low-pressure pressure switch is arranged at the suction of a compressor in the air-conditioning unit The two ends of the bypass solenoid valve are respectively communicated with the exhaust end of the compressor and the input end of the evaporator in the air conditioner unit by means of pipelines. By combining software and hardware, the present invention advances the low-voltage protection measures of the air-conditioning system before the occurrence of low-voltage faults through the automatic control of unloading start-up and the automatic control of temperature drop, which can significantly reduce the failure rate of the low-voltage protection of the system.

Description

technical field [0001] The invention belongs to the technical field of rail vehicle air conditioners, and in particular relates to a low voltage protection method for rail vehicle air conditioners. Background technique [0002] Most of the air conditioners currently used in rail vehicles are mainly fixed-frequency air conditioners, and their low-voltage protection methods are mainly hardware and low-voltage switches. The number of times of protection of low-voltage switches is recorded, fault lockout, and fault reset through software. Low pressure protection for refrigeration systems. [0003] Refrigeration in the spring and autumn transitional seasons when the external temperature is low, the set temperature inside the car is low during cooling and / or the air supply volume is too small due to dirty air conditioner filters, etc., which will make the evaporation temperature of the air conditioner unit lower than the freezing point of water, and the evaporation Frosting occur...

AI Technical Summary

Problems solved by technology

[0004] The above-mentioned low-voltage protection method can only try to avoid the system being locked by low-voltage protection, but its protection is based on the fact that the low-voltage switch has already activated, and there is no predictive automatic control of the operation of the refrigeration system to adjust in advance to avoid low-pressure Switch action, at this time, the refrigeration system may have frost and spray water, or the system cannot be prevented from being locked by low pressure protection in the end.

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