Liquid injection control method and system for heat recovery unit

Abstract

The invention discloses a heat recovery type machine set liquid jet control method and a system. The heat recovery type machine set liquid jet control method comprises the steps of detecting a suction pressure and a discharge pressure of a compressor, opening an electronic liquid jet expansion valve when the suction pressure and the discharge pressure exceed a preset target pressure operation range and adjusting the opening of the electronic liquid jet expansion valve to a preset initial step number to conduct the liquid jet; detecting the discharge temperature of the compressor and continuously adjusting the opening of the electronic liquid jet expansion valve from the initial step number when the discharge temperature is greater than or equal to a preset target discharge temperature till the discharge temperature is detected smaller than the target discharge temperature; detecting the discharge superheat degree of the compressor after the discharge temperature is detected smaller than the target discharge temperature and adjusting the opening of the electronic liquid jet expansion valve when the discharge superheat degree exceeds a preset target discharge superheat degree range so that the discharge superheat degree can be within the target discharge superheat degree range. By means of the heat recovery type machine set liquid jet control method and the system, the discharge temperature of the compressor is reduced, the occurrence of liquid backflow is avoided, and the operation reliability of the machine set is improved.

Description

technical field [0001] The invention relates to the technical field of air conditioning, in particular to a liquid injection control method and system for a heat recovery unit. Background technique [0002] The heat recovery unit can realize the secondary utilization of heat energy and reduce the direct consumption and emission of energy. With the rapid development of the economy and the improvement of people's living standards, domestic hot water supply and air conditioning in public places and individual residences have become a common demand. In this context, heat recovery units are increasingly popular. [0003] The heat recovery unit needs to operate in a wide range of ambient temperature, especially in winter, when the ambient temperature drops to -10~-15°C, the hot water heating capacity of the heat recovery unit will decrease accordingly, but at this time it is When the demand for hot water is the highest (usually the outlet temperature of hot water is as high as 5...

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Problems solved by technology

[0005] Based on this, it is necessary to address the defects and deficiencies of the prior art and provide a heat recovery type unit liquid injection control method and system to solve the problems of liquid return and high exhaust temperature when the unit works under low temperature and high load conditions. question

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