Hot air defrosting system for refrigerator and control method of hot air defrosting system

Abstract

The invention provides a hot air defrosting system for a refrigerator and a control method of the hot air defrosting system. The system comprises a defrosting branch. The defrosting branch is connected between an outlet of a compressor and an inlet of a freezing evaporator in parallel. The system further comprises a controller, a freezing chamber wall temperature sensor connected with the controller and arranged on the surface of the freezing chamber evaporator, a compressor suction temperature sensor arranged on the surface of a compressor suction pipeline, and a second two-position three-way valve arranged on an outlet of the freezing chamber evaporator. A first two-position three-way valve is also connected with the controller. The system further comprises a second capillary pipe, and the second capillary pipe is independently connected to the position behind the freezing evaporator and in front of a refrigerating evaporator in parallel through the second two-position three-way valve, or connected with the refrigerating evaporator in series and then connected to the position behind the freezing evaporator and in front of a liquid storage device in parallel through the second two-position three-way valve. The invention further provides the control method. By the adoption of the hot air defrosting system and the control method, the refrigerating evaporator of the refrigerator is complete in defrosting operation, defrosting energy consumption is low, defrosting time is short, and the temperature rise of a freezing room is small.

Description

technical field [0001] The invention belongs to the technical field of defrosting of refrigerators, and in particular relates to a hot gas defrosting system of a refrigerator and a control method thereof. Background technique [0002] When the air containing water vapor in the refrigerator flows through the evaporator, since the temperature indicated by the evaporator is mostly below 0°C, the water vapor will adhere to the surface of the evaporator and frost will form. As the refrigeration process progresses, the thickness of the frost layer will further increase, resulting in The thermal resistance between the evaporator and the air in the freezer increases, which reduces the heat transfer coefficient of the evaporator and affects the heat transfer of the evaporator, thus reducing the cooling efficiency and affecting the cooling effect of the refrigerator. Power consumption, so the refrigerator should be defrosted in time. [0003] At present, most direct cooling refrigera...

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Problems solved by technology

[0005] 1. The efficiency of defrosting by electric heating is low. Only about 15% of the total power consumption of electric heating elements is used for defrosting, and the rest of the heat is dissipated into the freezer compartment of the refrigerator, resulting in an increase in the temperature of the freezer compartment. , the heat load of the refrigerator increases, and when the system turns to cooling mode, the energy consumption of the refrigerator is further increased;

[0006] 2. The electric heating defrost is defrosted from the outside to the inside, which is prone to problems of incomplete defrosting and long defrosting time;

[0007] 3. The use of electric heaters has potential safety hazards such as electric leakage and fire

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