Heat pump unit electronic expanding valve control method and heat pump water heater

Abstract

The invention discloses a heat pump unit electronic expanding valve control method. The heat pump unit electronic expanding valve control method includes the following steps that firstly, the exhausttemperature of a compressor is divided into three control intervals which are a first control interval, a second control interval and a third control interval correspondingly; and secondly, the exhaust temperature of the compressor is periodically detected, and the control interval in which the current exhaust temperature is located is judged, wherein a, if the current exhaust temperature is located in the first control interval, the gas sucking overheat degree is adopted for performing control, b, if the current exhaust temperature is located in the second control interval, the exhaust temperature is adopted for performing control, and c, if the current exhaust temperature is located in the third control interval and the lasting time is t1 or above, valve opening is performed for n stepsevery other fixed time. Due to the electronic expanding valve control method, the adjusting relationship is determined according to the water temperature difference and the exhaust temperature difference, the exhaust temperature is limited in a reasonable interval, maximization and rapidity of heating hot water are guaranteed, stability of a system can also be guaranteed, and reliable running of the system is guaranteed.

Description

technical field [0001] The invention relates to the technical field of heat pumps, in particular to a control method for an electronic expansion valve of a heat pump unit and a heat pump water heater. Background technique [0002] The electronic expansion valve control mode in the current air-conditioning heat pump is generally suction superheat control or exhaust superheat control, in which the suction superheat control is to adjust the opening of the electronic expansion valve according to the difference between the suction temperature and the evaporation temperature. , the exhaust superheat control is to adjust the opening of the electronic expansion valve according to the difference between the exhaust temperature and the condensing temperature. These two control modes have their advantages and disadvantages. The former uses effective suction to control the flow of the system, makes full use of the system capacity, and exerts the optimal efficiency of the system, but whe...

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Problems solved by technology

[0004] In order to solve the problem that the control of the electronic expansion valve of the existing heat pump unit adjusts the working environment with a large temperature difference, if the suction superheat degree control or the exhaust superheat degree control is used alone, it cannot adapt to the comp

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