Study On Characteristics Of Liquid Desiccant Air Conditioning System

With environmental issues becoming more serious, energy saving has become a general direction of social development. According to a survey, building energy consumption accounts for more than 30% of the total energy consumed by society, while the energy consumption of air conditioning systems in the building energy consumption has accounted for about a half of it. Therefore, reducing the energy consumption of air conditioning systems, research and design a more rational way of air conditioning has become a subject of attention.Temperature and humidity independent control is a relatively new type of indoor air conditioning plan, which has the advantage of improving indoor air quality, and the core idea is to use two sets of equipment to on handle temperature and humidity of indoor air, which called significant latent heat treatment equipment and heat treatment equipment. In this paper, one of the latent heat handle equipment- liquid desiccant air conditioner driven by heat pump conducted a series of studies.Firstly, the study makes a heat and mass transfer analysis to liquid desiccant air conditioner driven by heat pump and build mathematical model. With coupling each model, the study using a computer program to establish a computer simulation platform of entire liquid desiccant air conditioner driven by heat pump.Then, this paper uses the experiment to verify the accuracy of the simulation platform. The paper built experimental platform of liquid desiccant air conditioner driven by heat pump, and maked its multi-condition tests. In addition, part of the actual use of the Chongqing area in a heat pump type liquid desiccant unit also conducted on-site field testing. The results showed that the computer simulation platform for the air temperature forecast deviations were less than 5%, the forecast deviation exhaust also substantially within 10%, with higher accuracy.Then, this paper built simulation platform solution for heat pump type dehumidifier filler size, heat exchange and other series simulation optimization. Through simulation makes a change to the same filler volume ratio of height to length and dehumidifying efficiency and total heat exchange efficiency. Simulation of surface latent heat, the total heat exchange efficiency is higher than the same length in a certain range logarithmic distribution. Meanwhile, the total heat exchange simulation module presents the total heat exchange efficiency and the relationship between the series, simulation results show that, with respect to a heat recovery mode, multi-stage heat recovery efficiency significantly improved, but in the heat recovery after reaching four series, enhance the efficiency is very limited. For altitudes paper for heat pump type liquid desiccant unit also carried out some simulation studies, results showed: at different altitudes, sensible heat treatment capacity of the unit is not much difference. But there is a greater change about dehumidifying capacity at different altitudes: with increasing elevation, dehumidification capacity is waning.After that, paper run control program for heat pump type liquid desiccant unit in temperature and humidity control system were discussed for different outdoor climate, proposed control scheme heat pump type liquid desiccant units and sensible heat treatment equipment. Especially for conventional fan coil as the coupling end and run a heat pump type liquid desiccant units are discussed in detail, found study shows that conventional coil run in high temperature conditions with increasing water temperature, in order to save energy for the return water temperature It should be gradually reduced.At last, with a specific project cases using Designbuilder load calculation of buildings annual load. The study used a computer program to establish ground source heat pump, heat pump type liquid desiccant unit energy consumption calculation model, the computing device energy consumption throughout the year. The results show that the use of a heat pump type liquid desiccant units and ground source heat pump operating mode coupling than the separate ground source heat pump system energy saving of 8%, relative to conventional boilers and chillers way saving 34%.