| With the constant development of clean energies,the advantages of solar energy have become increasingly prominent,thus gaining growing attention for applications of the solar energy technology.A majority of refrigerating devices rely on the state grid.Consequently,areas with the refrigeration demand but not yet covered by the state grid have been faced with the limitations to have their demand satisfied.Combining the photovoltaic system and the refrigeration system,this paper designs and develops the environmentally-friendly refrigerated cabinet which is independent from the state and with a strong applicability.Development of such a refrigerated cabinet holds practical significance of the improvement of people ' s quality of life in the remote areas and development of the cold chain logistics.A complete and stable solar energy tracking system is the most effective device to make full use of the solar energy.This paper,by referring to prior researches,puts forward a design method for the sun tracking servo control system,and makes a single-axis light-following solar panel with a proper precision and applicable to the refrigerated cabinet.The device features a plate shape,and has the servo motor matched with the solar cell unit one by one to realize the synchronous light following of multiple solar cell units.Meanwhile,this device can replace the traditional fixed solar panel on a large scope.The advantage of the light-following solar panel lies in the light following through cell units to achieve efficient utilization of the solar energy and improve the conversion rate of the solar energy.Additionally,it can address the limitations of the existing light-following solar panels,including their occupation of a large area and space.In this way,the device design can greatly expand the application scope of the light-following solar panels.The comparative experiment is conducted to verify that the photoelectricity conversion rate of the lightfollowing solar panels is superior to that of the fixed solar panels when it is sunny or overcast and rainy,and the experiment finding is basically consistent with the theoretical computing results.After the reliability of the light-following solar panel is verified,it is adopted as the powersupply system of the refrigerated cabinet.Then,the power supply performance of the photovoltaic system is experimentally studied under the daylight and simulated night conditions to verify that the power supply system can provide steady voltage and current to ensure the independent and steady operation of the refrigerated cabinet.In the experiment process of the refrigerating system of the refrigerated cabinet,the refrigerant charge is changed,and the refrigerating system's evaporation temperature,compressor's discharge pressure,and temperature reduction rate within the refrigerating chamber are monitored to finally identity the optimal refrigerant charge for the refrigerating system to be around 120 g.Furthermore,under the condition of optimal charge,the experimental data of the refrigerating system's key components are comprehensively compared under different loads.It is identified that the operation status of the refrigerated cabinet is the best under the water load of 1,000 ml.At last,energy efficiency analysis is conducted of the photovoltaic direct current refrigerated cabinet under the best operation status,and the improvement plan is proposed.To sum up,to study the light-following solar panel is of vital engineering significance to make fuller utilization of the solar energy,and improve the solar energy utilization rate,and can boost the applications of the light-following solar panels.Additionally,the match between the refrigerated cabinet and the photovoltaic system,and their operation experiment can accumulate important data for the research into the photovoltaic power generation and refrigerating system,and provide references for the promotion of the solar refrigerated cabinet. |
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