Design And Experiment Of A Solar Thermoelectric Refrigerator And Analysis Of Its Energy Saving Effect

Solar cooling is a kind of refrigeration method with good seasonal matching.It has the advantages of light weight,fast cooling speed,anti vibration and so on.The solar energy is generated by the solar photovoltaic effect,and can be directly supplied to the semiconductor refrigeration piece after the voltage and current stabilizing.Refrigeration has no environmental pollution in this way,it can not only reduce the consumption of fossil energy for family use,can also be used for portable solar cooling box,which has very practical value in medical treatment,scientific research and daily life.This study first analyzes energy transformation method,and then according to the demand of design system,according to the system needs to design and manufacture a solar cooling box,with the photovoltaic power generation system,refrigeration system,control system and energy storage system.According to the national standard and some data,the calculation can collect all kinds of data,design the refrigerator,select the photovoltaic system,the control system and the energy storage system.In this study,we have developed a kind of solar energy refrigerating box,which is composed of photovoltaic power generation system,refrigeration system,control system and energy storage system.Through the control of experimental variables in sunny and cloudy days,affecting factors of illumination is measured.Through running the refrigeration system and the entire system,compatibility of the system is tested.On this basis,the cold storage material was added and the operation of the system was tested.The experimental results show that there is a great difference in light intensity between sunny days and cloudy days,and the maximum power of cloudy days is less than 50% of that in sunny days.Within 80 minutes,non-loaded cooling curve showed that the cooling rate of the system decreased as time passed,and the slope of the cooling curve changed gradually from steep to gentle.The final temperature difference is related to the cooling power: the greater the power,the greater the temperature difference.Compared with the refrigerator without cold storage material,the cooling time can be reduced by 5.4% by putting double load in refrigerator which has cold storage material which has been cooled to the temperature of 8 ?.Under the condition of refrigerator with cold storage material,the cooling rate of the load is fast at the beginning.And it decreases with time obviously.Under the condition of refrigerator without cold storage material,the load cools averagely,and the cooling rate decreases slowly.In the noon,sunlight is strong,and all access to the photovoltaic panels will sometimes exceed the maximum charging power.At this time,the number of photovoltaic panels should be reduced.In order not to waste,an additional charging system can be used to store the energy generated by the photovoltaic panels reduced.When the system is working,the voltage is usually not up to the rated value.The maximum refrigerating condition of the system should be measured and the voltage and current should be controlled at this level.In the experiment,the use of cold storage material can reduce the running time when putting in new load at the time when there is adequate sunlight.And the ratio of running time to stop time can be increased.As a result,the energy saving rate is 8.5% on the sunny day,and 6.8% on the cloudy day.