Experimental Research On All Working Conditions Of Reheating And Dehumidifying Heat Pump System

The air inlet temperature and humidity in an underground project is quite special.The traditional dehumidifier cannot realize the free control of air temperature and humidity,and cannot satisfy the task of free adjustment of temperature and humidity in an underground project.For underground engineering to adjust the temperature and moisture tasks at the same time,this paper studies a new type of reheat desiccant heat pump system,the outlet air temperature and humidity to cope with different inlet air conditions and requirements,the system provides four kinds of operation mode,respectively is: cooling dehumidification mode,dehumidifier,temperature modulated mode,the mode of temperature and heating mode.The new dehumidification heat pump system not only solves the limitation that the traditional cooling dehumidification system can only cool down and dehumidify,but cannot realize the free control of air temperature and humidity,but also provides a new idea for the innovative development and application of the traditional cooling dehumidification system.Through the establishment of a reheat dehumidification heat pump system test unit,this paper has carried out experiments on 22 working conditions of four operating modes,namely,cooling dehumidification mode,heating dehumidification mode,temperature regulating dehumidification mode and heating mode.The test results show that when the reheat dehumidification heat pump system runs the cooling dehumidification and temperature regulating dehumidification modes,the ideal wind output effect can be obtained.In the heating dehumidification mode and heating mode,the air outlet temperature is lower than the design and calculation.However,if the frequency of the compressor is increased,the ideal air outlet temperature can be reached.The COP of the system can reach 6.32,and the SMER can reach 5.59kg/(h· k W).Followed by affecting the system out of the wind effect and energy efficiency of key operation factors has carried on the detailed analysis of the control variable method is adopted,the change of temperature of the intake air volume,into the wind,the air humidity,frequency of compressor,refrigerant tee proportioning valve five key operation parameters,such as unit to explore the change of working condition and the influence of operation parameters on the system performance.The test results show that the air volume,air inlet temperature,air inlet humidity and compressor frequency will affect the air outlet temperature,air outlet humidity,cooling capacity,heat production,dehumidification capacity,COP and SMER of the system.The change of opening degree of refrigerant tee proportional regulating valve will affect the outlet temperature and reheat.