Experimental Study On Potable Food Thermotank

With the rapid development of society,food safety has received more attention.In the past,people only paid attention to the refrigerated preservation of foods,but they neglected the problem that foods could easily grow bacteria below 60°C.The portable food thermotank is designed to keep the temperature inside the thermotank constant at 60°C.When people need to go out for food or take delivery in a timely manner,they can maintain a temperature environment where the food is free of microorganisms to ensure food safety.This article mainly studied(1)the thermal characteristics of the polypropylene plastic foam(EPP)incubator;(2)simulated the temperature curve in the paraffin solidification process;(3)optimized the heat dissipation structure of the phase change heat accumulator.Through the experimental analysis of the insulation performance of the EPP incubator,it was found that the food generally cools down by 20-25°C within one hour in the EPP incubator.Only foods with an initial temperature of 85°C can remain in the incubator for more than 60°C for one hour.In real life,it is not guaranteed that the food temperature is higher than 85°C and then brought into the incubator,so the insulation effect of the incubator is also difficult to eliminate the safety and health problems brought about by food cooling.Therefore,the necessity of adding a phase change heat storage material has been proposed.By analyzing the thermal performance of the EPP incubator,the heat transfer coefficient and the heat storage coefficient of the incubator were measured.The heat transfer coefficient provided reliable data support for the subsequent numerical simulation.And through the comparison of three experimental methods,the feasibility of using non-steady state method to measure heat transfer coefficient in a small box is verified.The paraffin phase transition heat transfer numerical simulation was used to compare the cooling process of paraffins with different melting points and the paraffin wax melting point temperature of 91°C was determined.Based on this,the temperature field inside the incubator with a temperature of 91°C was simulated.It was confirmed that the phase change material added in the incubator was a paraffin wax with a melting point of 91°C,and the packaging method was a metal tube package.The effect of using a copper tube and an aluminum tube was compared on the material of the packaging container,and the aluminum tube was finally selected as the package.Container,made of phase change heat storage tube.The heat dissipation method of the heat storage tube was optimized through experiments,and the structure of the phase change heat accumulator was designed and verified experimentally.