Refrigeration system utilizing natural circulation of heat to carry out defrosting thereof

Abstract

A refrigeration system utilizing natural circulation of heat to carry out defrosting thereof provides a refrigeration cycle path and a defrost cycle path, and is characterized by a heat energy storage device located at an output of a compressor that is common for the two cycle paths. High-temperature high-pressure overheated refrigerant output by the compressor passes through the heat energy storage device and releases part of heat energy thereto for storage. When the refrigeration system is switched from the refrigeration cycle path to the defrost cycle path, the compressor is turned off and three-way valves upstream an evaporator are opened, a pressure difference between the heat energy storage device and the evaporator drives the hot refrigerant to directly flow through the three-way valves into a coil of the evaporator to melt frost on the coil from inner to outer side while the refrigerant keeps circulating along the defrost cycle path.

What is claimed is: 
     
         1 . A refrigeration system utilizing natural circulation of heat to carry out defrosting thereof, comprising a compressor, a heat energy storage device, a condenser, an expansion valve, an evaporator internally having a coil and a plurality of fins, a liquid collector and a plurality of three-way valves to provide a refrigeration cycle path and a defrost cycle path; the compressor being common for the refrigeration cycle path and the defrost cycle path, and the heat energy storage device being installed at an outlet of the compressor, so that a refrigerant compressed by the compressor and output as a high-temperature, high-pressure overheated refrigerant passes through the heat energy storage device and releases part of heat energy, and the released heat energy is stored in the heat energy storage device; whereby when the refrigeration system is switched from the refrigeration cycle path to the defrost cycle path for defrosting the evaporator, the compressor is turned off and the three-way valves located upstream the condenser and the evaporator are opened, a pressure difference between the high-temperature and high-pressure refrigerant in the heat energy storage and the low-temperature and low-pressure refrigerant in the evaporator drives the refrigerant to directly flow through the three-way valves located in the defrost cycle path and upstream the evaporator into the coil of the evaporator without passing through the condenser and the expansion valve; and when the hot refrigerant flows through the coil, frost externally accumulated on the coil and the fins of the evaporator is melted from inner to outer side; and, due to the pressure difference between the heat energy storage device and the evaporator, the refrigerant keeps circulating along the defrost cycle path to defrost the evaporator. 
     
     
         2 . The refrigeration system utilizing natural circulation of heat to carry out defrosting thereof as claimed in  claim 1 , wherein the heat energy storage device is formed of a heat energy storage material having a relatively high specific heat. 
     
     
         3 . The refrigeration system utilizing natural circulation of heat to carry out defrosting thereof as claimed in  claim 1 , further comprising a heat device provided on the heat energy storage device.