Low pressure control method, device, heat pump system and storage medium of chiller and hot water unit

Abstract

The invention relates to a low-pressure control method and device for a water cooling and heating unit, a heat pump system and a storage medium. The method comprises the following steps that a low-pressure switch signal is acquired, wherein the low-pressure switch signal is a low-pressure switch feedback signal of the water cooling and heating unit; when the low-pressure switch signal is a switch-off signal, the air suction pressure of the water cooling and heating unit is reduced until the low-pressure switch signal is a switch-on signal. By adopting the method, the situation that low-pressure-over-range occurs in the operation process of the water cooling and heating unit can be effectively avoided, then the evaporation temperature of the unit is effectively controlled, the refrigerant circulation amount and the oil discharge rate of a compressor are reduced, the reliability operation of the unit compressor is ensured, meanwhile, the air suction pressure of the unit is monitored andpre-warned through a low-pressure switch, so that the design cost is saved to the greater extent.

Description

technical field [0001] The present application relates to the technical field of air conditioning, in particular to a low-pressure control method, device, heat pump system and storage medium of a cold and hot water unit. Background technique [0002] At present, air-source heat pump chillers and hot water units have been widely used in projects of different scales in various industries such as office buildings, hotels, hospitals, factories, and residences, and their market share has always been high. [0003] Traditional cold and hot water units generally have high and low pressure switches, which are usually used as pressure protection devices for cold and hot water units. They use the principle of mechanical devices to control the high and low pressure braking of cold and hot water units to protect the The unit is not affected by abnormal high and low pressure. [0004] However, the high and low pressure switches in the traditional cold and hot water units are only for th...

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Problems solved by technology

[0004] However, the high and low pressure switches in the traditional cold and hot water units are only for the low pressure protection of the cold and hot water units, and cannot accurately control the situation of low pressure exceeding the range of the cold and hot water units. In the case of switching, if the heating is switched to cooling, the water temperature will be higher at the initial stage of the unit’s start-up operation. At this time, the low-pressure out-of-range situation will occur. , the system has a high evaporation temperature and a large amount of refrigerant circulation, which can easily lead to an increase in the oil discharge rate of the compressor, and long-term operation is more likely to cause damage to the compressor such as lack of oil

[0005] Therefore, the traditional low pressure control method of hot and cold water units has the problem of being unable to effectively control the low pressure exceeding the range.

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