Antifreeze control method and system for heat pump unit

Abstract

The invention discloses a heat pump unit antifreeze control method and system of the present invention. The method includes detecting the current working mode of the heat pump unit, and detecting whether the current state meets one of the refrigeration antifreeze conditions in the refrigeration mode, and if so, controlling the heat pump unit to enter the antifreeze protection mode ; In the heating mode, check whether the current state meets all the heating and antifreeze conditions, and if so, control the heat pump unit to enter the antifreeze protection mode. The system includes a mode detection unit, a refrigeration antifreeze detection unit and a heating antifreeze detection unit. The invention can effectively prevent the freezing and bursting of the evaporator caused by the low evaporation pressure when the water flow rate of the unit is too small when cooling in summer; Negative values ​​appear in the heating mode, which greatly improves the comfort of the user, and can also prevent the situation that the machine cannot be turned on because the temperature is too low when it is just turned on. The invention can be widely used in heat pump units.

Description

technical field [0001] The invention relates to the technical field of heat pump control, in particular to a method and system for antifreezing control of a heat pump unit. Background technique [0002] In the past, the antifreeze control method of the heat pump is: when the unit is cooling, when the outlet water temperature is ≤5°C, the controller controls the unit to start the antifreeze protection; when the unit is heating, when the outlet water temperature is ≤4°C, the controller controls the unit to start the antifreeze protection. Although such a control method serves the purpose of anti-freezing protection, the following problems still occur during later user use: [0003] When the unit is cooling in summer, if the unit is not equipped with a water supply valve or the water flow switch flap is faulty, the water flow of the unit is likely to be too small, which makes the evaporation pressure of the unit system too low, causing the evaporator to freeze instantly, and th...

AI Technical Summary

Problems solved by technology

[0003] When the unit is cooling in summer, if the unit is not equipped with a water supply valve or the water flow switch flap is faulty, the water flow of the unit is likely to be too small, which makes the evaporation pressure of the unit system too low, causing the evaporator to freeze instantly, and the evaporator is easy to be damaged. Freezing explosion; and when the unit is heating in winter, it often fails to start the machine because the outlet water temperature is too low when it is just started.

[0004] At the same time, in many cases, the current state of the unit displayed on the controller is heating, but the entire unit system is actually operating in cooling mode because the temperature difference between the inlet and outlet water is negative, which greatly affects the user's comfort.

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