Experimental Study On Refrigeration Performance Of Composite Magnetic Refrigerator

With the development of the times,refrigeration technology has a great impact on modern society.It plays an important role in daily life,biology,medicine,aerospace and petrochemical industry.However,traditional refrigeration technologies such as compression and absorption refrigeration technologies are prone to serious environmental problems such as the ozone layer and the greenhouse effect.According to the provisions of the International Environmental Protection Law Convention,in 2020,developing countries will basically eliminate environmentally harmful refrigerants such as HCFCs and CFCs in2030.However,the current alternative working fluid still faces some problems.Therefore,there is an urgent need for a new type of efficient green refrigeration technology.Magnetic refrigeration technology has the advantages of green environmental protection,high efficiency,low vibration,low noise and stable operation.Provide an effective solution to solve the environmental problems brought by traditional refrigeration technology.It makes one of the most researched and most valuable refrigeration technologies.The so-called magnetic refrigeration technology is a new type of refrigeration technology that uses the "magnetothermal effect" of magnetic materials to refrigerate.This paper mainly takes the composite magnetic refrigerator as the research object.The effects of three aspects of magnetic refrigerator structure,operating parameters and heat transfer fluid on the refrigeration performance of the system were investigated experimentally.(1)Influence of magnetic refrigerator structure on system refrigeration performance.The structure of the cold-end heat exchanger of the magnetic refrigerator,the structure of the hot-end heat sink,the filling method of the magnetic medium and the influence of the active regenerator port on the refrigeration performance of the system have been explored.A method for improving the refrigeration performance of a magnetic refrigerator system by changing the structure and heat dissipation mode of the cold-end heat exchanger and the heat-end heat dissipation.It is easier to obtain a larger hot and coldend temperature span than to fill the active regenerative with a multi-layer magnetic working fluid than a single-stage magnetic working fluid.It is easier to improve the system refrigeration performance than the active port of the active regenerator.(2)Influence of operating parameters of magnetic refrigerator on system refrigeration performance.The effects of the ambient temperature of the magnetic refrigerator,the angle of the heat exchange zone,the angular velocity of the heat exchange zone and the angular velocity of the non-heat exchange zone on the refrigeration performance of the system were investigated.Get the best refrigeration performance at20 ? in the Curie temperature.There is an optimum value for the angle of the heat exchange zone.When the angle of the heat exchange zone is 20 °,the actual cooling capacity of the system is the strongest.There is an optimum value for the angular velocity of the heat exchange zone of the system.When the angular velocity of the heat exchange zone of the system is around 865 rad/s,the refrigeration capacity of the system is the strongest.The higher the angular velocity of non-heat exchange,the better the refrigeration performance of the system.(3)Influence of heat exchange fluid of magnetic refrigerator on refrigeration performance of system.The effects of single-cycle volume of different heat transfer fluids and heat transfer fluids on the refrigeration performance of the system have been explored.The system's refrigeration performance will decrease with the increase of alcohol concentration and acetone concentration.When deionized water is obtained as the heat exchange fluid,the refrigeration effect of the system is significantly higher than that of alcohol and acetone solution.At the same time,the cooling effect of the alcohol solution is higher than that of acetone.This shows that the greater the specific heat capacity of the heat transfer fluid,the better the cooling performance of the system.The actual refrigeration performance of the system will decrease first and then increase with the increase of the single cycle volume of the heat exchange fluid.When the single cycle volume is 116 ml/time,the actual cooling performance of the system is the best.