Influences of Temperature of Vapour-Condenser and Pressure in the Vacuum Chamber on the Cooling Rate during Vacuum Cooling
The temperature of vapour-condenser below 0℃ and the final pres-sure in the vacuum chamber below 0.61kPa during vacuum cooling were ex-perimentally analysed in this paper. The temperature of vapour-condenser, 2t,-35℃,-39t and-71℃, and the final pressure in the vacuum chamber, 0.3kPa, 0.4kPa, 0.5kPa and 0.61kPa, were chosen. The experimental results showed that the cooling rate varies with the temperature of vapour-condenser and the final pressure in the vacuum chamber. Water vapour becomes the frost on the surface of vapour-condenser when the initial temperature of vapour-condenser is below 0t, which is helpful to trap water vapour for vapour-condenser. In addition, the formation mechanism of frost at the surface of vapour-condenser was analysed in this paper. The cooling time for vacuum cooling can be reduced when the final pressure in the vacuum chamber varied from 0.4kPa to 0.61kPa. However, the surface temperature of cooked meat occurred freezing when the final pressure in the vacuum chamber was 0.3kPa. Therefore, in order to reduce the cooling time and avoid freezing, the temperature of vapour-condenser should be set around-30℃～℃ and the final pressure in the vacuum chamber can be defined at from 0.4kPa to 0.61kPa.
Temperature Pressure Vapour-condenser Vacuum cooling
Tingxiang Jin Gailian Li Chunxia Hu
School of Mechanical & Electricity engineering, Zhengzhou University of Light Industry,5 Dong Feng Road, Zhengzhou 450002, Henan Province, P. R. China
国际会议
南昌
英文
41-52
2010-10-22（万方平台首次上网日期，不代表论文的发表时间）