The Theoretical Analysis And Experimental Study On Enclosed Heat-pump Drying System With Auxiliary Condenser

Drying technology is widely used in various fields of national economy. Heat pump drying system can effectively adjust the temperature and humidity of the air. And the heat pump is an excellent drying machine with the characteristic of high quality, wide range of application and so on. This paper mainly studies the influence of the parameters on the drying system and drawing the drying characteristic curve.In this paper, the research mainly focuses on the following aspects:Using the First Law of thermodynamics to analysis and obtain the SMER(Specific Moisture Extraction Rate) in different forms of heat pump drying systems. We also use EES to obtain the relationship between the parameters(air bypass rate, evaporation temperature, condensation temperature, etc.) and SMER. Therefore, we obtain that there is a optimal air bypass rate when the system running. In the air circulation, we should try to improve the air humidity and temperature of the drying chamber inlet. It is not we generally think the air humidity smaller, the SMER greater.The heat pump drying system is established, which uses condensers in parallel to more accurately control the temperature of the drying chamber, uses the bypass air method to better control the moisture into the drying chamber. The system has been optimized design and the equipment selection.Introducing the theory of thin-layer drying and diffusion equation model. Using the semi-empirical models, we obtain the drying characteristic curve has in different drying temperature and different thickness.By adjusting the temperature and humidity of the inlet of drying chamber to meet the three stages of drying material(preheat stage, fast drying stage and last drying stage). Get the curve of parameters and material weight as time change. The conclusions of the theoretical calculations has been verified.The enclosed heat pump drying system with auxiliary condenser can better control the drying process and the conclusions obtained in this paper can provide theoretical basis and experimental data.