| Refrigerators being easy for the storage of perishable foods have attracted more and more attentions. Study on the influence of insulation cover and the hollow glass door on the temperature field distribution inside the freezer were measured by experimental and numerical simulation methods in this paper, when the freezer is unloaded, the distribution of the temperature field in the refrigerated and temperature distribution of the cross section along the width direction were measured with the insulation cover being open and closed. And the temperature distribution of the food packages in the freezer were measured with the insulation cover being open and closed. Then the temperature distribution in the freezer would be obtained. During the simulation study, the temperature and velocity distribution would be investigated with different inlet velocity and the hollow glass door being open and closed, and the relationship between the temperature and velocity were analyzed. The results showed that:(1) According to the simulation, when the insulation doors were installed, the end side of air curtain may be bent down along the inner wall, emerging the end wall vortex, annular flow of air inside the freezer is the main reason for the lag of the temperature field; different air curtain inlet velocity(0.3m/s, 0.5m/s and 0.8m/s) had little effect on the temperature value when the temperature in the freeze in stable, but as the wind speed increases, the cooling rate in the initial stage get faster and the temperature field get more uniform, 0.8m/s is the optimum supply velocity for the freezes considering the temperature uniformity and temperature value when the field is stability.(2)When the hollow glass door is not installed, cold air curtain diffused in the rear portion and flow into the external environment through the open part of the freezer, which resulted a slower cooling rate and a higher temperature value when stable comparing with the hollow glass door being installed at the same inlet speed; the distribution of temperature field inside the freezer is uniform when the velocity is 0.8m/s and 1.5m/s, and it can meet the requirements of the frozen food. When the inlet velocity is 0.8 m/s, the air curtain could be able to complete cover the entire exposure. If the velocity continues to increase, it will cause a lot of cold air to flow into the external environment, which resulting the cold consumption increases, and fan power became larger, which is not conducive to energy conservation, so 0.8m/s is more conducive to the cooler temperature uniformity and energy savings.(3)When the inlet velocity is 0.8m/s, temperature stable value in the freezer with the hollow glass door is lower by 1℃ then the freezer without hollow glass door. The hollow glass door can not only reduce air curtain flowing into the external environment, but also reduce heat coming into the freezer.(4)In the experiment, the temperature in the freezer could maintain a low value(-2.3℃~-2.9℃) and well temperature distribution when the freezer is unloaded with the insulation cover closed, which can meet the requirements of the frozen food. When the insulation cover was opened, the maximum temperature difference between the measuring points is 2.5℃, and the temperature distribution was no longer uniform. The temperature range in the freezer was mainly in 0~1℃, which is not conducive to storage food.(5)When the freezer ran with load, the food package could effectively maintain a low temperature and well temperature distribution with the insulation cover closed; when the insulation cover opened, the top food package will serve as the role of the cold accumulating material to maintain the internal food pack a relatively low temperature. |
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