Study On Horizontal Low-temperature Display Cabinet Performance's Optimization

With a horizontal display cabinet as subject, the air curtain characteristic and the performance of refrigeration system were studied both in theory and experiment.The characteristics of air curtain flow and heat transfer is affected by many factors, such as the jet velocity jet temperature ,jet initial turbulence intensity, air curtain width, height and width of the exposure, the pressure and temperature on both sides of the air curtain. The performance of the air curtain determined and the temperature distribution uniformity and stability of the display case, there by determining the quality of the display of goods. The air curtain also insulates the inside of the cabinet from the outside environment ,and determined the frost on the evaporator, so as the energy cost.The air curtain characteristics directly influence the performance of open horizontal low temperature display case. The effects of the outlet structure amelioration on the characteristics of air curtain and the performance of the display case are experimentally investigated in this paper. The results show that the outlet speed uniformity along the length of display case increased, the uniformity of outlet temperature increased, the uniformity of temperature field inside the display case raised by 0.36%, the amount of single-cycle need cool reduced by 4.66%, single-cycle power consumption decreased by 6.63%. The improved air curtain outlet structure can ameliorate not only the characteristics of the air curtain but also the performance of the display case.By changing the number of fans and the wind output of the open low temperature display case optimize the air curtain characteristics and the performance of the display case. The research show that the display case with double fan is better than that with single, the amount of need cold reduced by 5.84%, power consumption decreased by 2.63%.Also can cover the cabinet with glass cover outside in order to improve operating characteristics of a horizontal display cabinet to achieve the purpose of improving the characteristics of air curtain flow and saving energy.It can block the exchange of heat and moisture outside the cabinet by the glass cover outside which can push and pull to maintain the temperature inside and reduce the involvement of water vapor and reduce the quantity of melting frost. But the cabinet with covered during the operation of the wind screen to properly regulate the speed of the wind to avoid surface condensation and fan cover such phenomena as blocking cream to maintain normal operation. The uniformity of temperature field inside the display case,the overall 21.20%. The amount of need cold reduced by24.2%, power consumption decreased by 10.5%.Based on the result above,the air curtain characteristic can be improved by reform the outlet .Choose the best outlet speed can improve the performance of air curtain, improve display case operating performance,to saving power consumption.For the refrigeration system, the stamped to the cabinet not only enable the stable operation of the display cases,but also to achieve energy efficiency.