Low temperature heating refrigerant flow matching control method and air conditioner

Abstract

The invention discloses a low-temperature heating refrigerant flow matching control method and an air conditioner, including the following steps: S1: the air conditioner enters the heating mode, and judges whether to enter the defrosting control; The electronic expansion valve restores the initial opening and starts the frosting timer. When the frosting timer reaches the frosting time, S3: start the valve adjustment timer; S4: when the valve adjustment timer reaches the expansion valve adjustment time, the electronic expansion valve closes one step. Determine whether the opening of the electronic expansion valve has fallen to the lower limit opening, if not S5: determine whether to enter the defrosting control, if so, S6: maintain the opening of the electronic expansion valve unchanged; S7: When the condition for entering the defrosting control is reached, Execute step S2, otherwise execute step S6. The invention dynamically matches the refrigerant flow rate and the heat exchange capacity of the evaporator during the frosting process, improves the low-temperature heating capacity, prolongs the frosting cycle, reduces energy consumption, reduces noise pollution, and improves use comfort.

Description

technical field [0001] The invention belongs to the technical field of air conditioners, and in particular relates to a low-temperature heating and refrigerant flow matching control method and an air conditioner. Background technique [0002] At present, the flow control of the low-temperature heating electronic expansion valve of the inverter heat pump air conditioner is too rough. One is that the expansion valve is set to a fixed opening during the entire frosting process. At the beginning of frosting, the refrigerant flow through the fixed opening can meet the matching requirements of the heat exchanger. It is required that the refrigerant can be completely evaporated, but in the process of low-temperature heating and frosting, as the frost layer increases, the heat transfer capacity of the evaporator gradually decreases, and the fixed refrigerant flow rate cannot be completely evaporated, resulting in less and less refrigerant and heat transfer capacity. Matching makes t...

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Problems solved by technology

[0002] At present, the flow control of the low-temperature heating electronic expansion valve of the inverter heat pump air conditioner is too rough. One is that the expansion valve is set to a fixed opening during the entire frosting process. At the beginning of frosting, the refrigerant flow through the fixed opening can meet the matching requirements of the heat exchanger. It is required that the refrigerant can be completely evaporated, but in the process of low-temperature heating and frosting, as the frost layer increases, the heat transfer capacity of the evaporator gradually decreases, and the fixed refrigerant flow rate cannot be completely evaporated, resulting in less and less refrigerant and heat transfer capacity. Matching makes the capacity attenuate rapidly and deteriorates the use effect of the air conditioner; one is to adjust the electronic expansion valve once according to the change of the evaporation temperature during the low-temperature frosting process, but this adjustment range is often too large, which will cause the evaporation pressure and evaporation temperature to increase. Instantaneous mutations occur, resulting in rapid growth of ice crystals, destroying the stability of the system's frosting process, thereby shortening the frosting cycle, causing frequent defrosting of the air conditioner, and bringing discomfort

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