Continuous heating and defrosting air source heat pump control method

Abstract

The invention discloses a continuous heating and defrosting air source heat pump control method. Low-voltage protection of a heat pump system is actively shielded during the period of defrosting, andthe low-voltage protection is started after the defrosting period; when any group of outdoor heat exchangers of all outer heat exchangers meets a defrosting condition and enters a defrosting state, acontroller records pre-defrosting opening values of all main electronic expansion valves matched with a first group of outdoor heat exchangers to be defrosted at the same specified time before a four-way valve is switched; the first group of outdoor heat exchangers enters the defrosting state after the four-way valve is switched; and the main electronic expansion valves opening matched with the first group of outdoor heat exchangers is a specified defrosting opening, and remaining main electronic expansion valves are respectively regulate opening according to outlet superheat degree of the outdoor heat exchangers matched with the main electronic expansion valves in the defrosting period of the first group of outdoor heat exchangers. The method is characterized in that heat can be providedin the defrosting, the operation of the heat pump is more stable, the defrosting time can be shortened, and the heating load of the heat pump is improved.

Description

technical field [0001] The invention relates to an air source heat pump control method capable of continuous heating and defrosting, and belongs to the technical field of refrigeration. Background technique [0002] The applicant of the present invention was authorized on June 29, 2016, and the invention patent with the patent number 201110355023.0 proposed a refrigerant three-way flow conversion device, and its system composition is as follows Figure 4 As shown, this patent can be used to design an air source heat pump that can realize continuous heating and defrosting, such as Figures 1 to 3 shown. exist figure 1 In the system shown, the air source heat pump has at least two sets of outdoor heat exchangers 4 and 5; when the outdoor heat exchanger 4 needs to defrost, the four-way valve 70 switches; and the four-way valve 80 does not switch, the outdoor heat exchanger 5 is still working normally, absorbing heat from the outdoor air, part of the absorbed heat is supplied...

AI Technical Summary

Problems solved by technology

When one main electronic expansion valve acts, it will inevitably affect the opening of the other main electronic expansion valve; The two corresponding main electronic expansion valves also work alternately; during this process, their openings also have a wide range of movements to meet the needs of the defrosting process; Simultaneous action, regulating the flow of refrigerant passing through the outdoor heat exchanger 4 and the outdoor heat exchanger 5, will inevitably affect each other, produce oscillation, delay the time to enter stable operation, and affect the heat supply of the heat pump; therefore, during the defrosting process , and after returning to normal operation after defrosting, if the two main electronic expansion valves are not properly controlled, it will inevitably affect the heat supply during the defrosting period and the period of returning to normal operation after defrosting, resulting in prolonged defrosting time and unit failure. Total accumulated heat supply reduction

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