Optimization And Study Of A Temperature And Humidity Independent Control Air-conditioning System Based On External Surface Evaporative Cooling Solution Dehumidification And Radiation Cooling

With the growth of the world economy and people's income,residents'requirements for the comfortable human settlements have increased.Indoor temperature and humidity are important parameters that affect human comfort.Air conditioning systems can maintain indoor temperature and humidity within a suitable range.The conventional air-conditioning system adopts the combined processing method of temperature and humidity,which will cause disadvantages such as energy waste,poor comfort and air quality.The proposed temperature and humidity independent control system can solves the above problems.The indoor temperature and humidity are controlled by independent systems.It provides conditions for the use of natural cold sources and low-grade energy.The temperature and humidity independent control system can saves energy and has good thermal comfort.This paper proposes a novel temperature and humidity independent control air-conditioning system based on external surface evaporative cooling solution dehumidification and radiant cooling.The indoor sensible heat is removed by a radiant floor,and the indoor humidity is removed by an external surface evaporative cooling solution dehumidifier which uses natural cooling.And the system combines the condenser and the solution regenerator to form a condenser-regenerator,and use the waste heat from the condenser to regenerate the solution.Mathematical models are established for each component and system,performance evaluation indexes are proposed for the devices and system,and Matlab software is used to simulate the effects of device parameters,fluid parameters and environmental parameters on the performance of different devices and system.Secondly,the physical model of the floor and the room is established,and use the CFD software to simulate.The influence of the chilled water inlet parameters and the radiation floor parameters on the radiation floor temperature is analyzed and the empirical formula is fitted.Then the indoor flow field is simulated and analyzed the indoor air distribution performance.When designing the device,the longer evaporator tube length of the evaporator is beneficial to improve the performance of the evaporator and the system.There is an optimal tube diameter of the evaporator.The use of a longer dehumidifier tube length and a larger number of dehumidifier tubes is conducive to the improvement of the performance of the external surface evaporative cooling solution dehumidifier and the system.In practical applications,in order to improve the system COP and system efficiency,the condense-regenerator should use a larger mass flow of regeneration air and regeneration solution.The external surface evaporative cooling solution dehumidifier should use a larger mass flow of dehumidified air.The larger mass flow rate of the dehumidification-regeneration cycle solution can achieve better performance.Through CFD simulation,it can be seen that condensation does not occur at the radiant cooling surface,which meets the requirements of indoor design,the roof radiation form is better,and the indoor flow field is evenly distributed.The research proves the feasibility of the proposed temperature and humidity independent control system.The conclusion of performance analysis can provide suggestions for the design and application of devices and system.