液体冷媒除霜系统的冷风机结霜性能研究

Study on the frosting performance of the air cold in the liquid refrigerant defrosting system

液体冷媒除霜具有在除霜期间制冷过程连续,库温波动小,无需附加能耗的优势。为了解决实验过程中结霜质量和结霜厚度难以测量的问题,并且为了探究系统的结霜规律,建立了在干工况、结露工况和结霜工况下从两相区到过热区的双联冷风机的热力学模型。结果表明:当环境温度为25℃,库温为-20℃时,结霜质量和结霜厚度随时间的增长逐渐变缓,管长在4.5m后的排管几乎不结霜。模拟结霜过程时,相对湿度从100%降低至40%时几乎不再结霜,结霜质量为0.11kg,与实验结果基本相同。

The liquid refrigerant defrosting process is continuous during the defrosting. The temperature fluctuation of the cold storage is small and the additional energy consumption isn＇t needed. In order to solve the difficulty of measuring the frosting mass and frosting thickness in the experiment process,and to investigate the law of the frosting formation,a thermodynamic model of the two stage air cooler from the two phase region to the hot zone under the dry condition,condensation condition and frosting condition was established. The results show that when the environment temperature is 25℃ and the cold storage temperature is-20℃,the frosting mass and the frosting thickness gradually decrease with the increase of the time and the part of the pipe behind the 4. 5 m does not frost. When the relative humidity is reduced from 100% to 40%,the frosting is almost no longer frosting,and the mass of the frosting is 0. 11 kg,which is basically the same as the experimental results.