Study Of The Performance Of Desiccant Wheel With Staged-regeneration And The Application Of Desiccant Wheel In The Air-conditioning System

With the development of the technology and the economy, people require morecomfortable environment in their life and work. The control of air humidity in theair-conditioning technology gets more and more attention. Because the improper airhumidity can not only affect people’s feeling of temperature and comfort, but also haveimportant significance in modern industrial and agricultural production. The rapiddevelopment of the air-conditioning industry has resulted in a sharp increase in thenetwork load, and accelerated the consumption of global energy and resource, and leadsto the deterioration of greenhouse gas emissions and air pollution and otherenvironmental problems. And dehumidification is a work with high energy consumption,which accounts for20%~40%of the total energy consumption of the air conditioning.So it makes a lot of sense to study the efficient dehumidifying technology for the socialenergy and the environment.The evaporative cooling technology uses water as refrigerant, which isenvironmental-friendly. And the system can use full fresh air, which can improve the airquality in the room, and without the consumption of compression work. So theevaporative cooling system has a high COP and energy-saving effect. Because oflacking of the dehumidification capacity, there are some restrictions on the applicationof evaporative cooling technology. In order to expand its range of application, it’snecessary to combine the dehumidification technology with the evaporative coolingtechnology. The desiccant wheel has developed rapidly because of its advantages inthese dehumidifying methods, such as the simple structure, easy maintenance, andtaking advantage of the low-grade energy. The combination of evaporative cooling withdesiccant wheel technology can not only play these advantages, but also overcome therestrictions on the application of evaporative cooling technology in high humidity areas,which causing the attention of many scholars and research.The purpose of this paper is to explore the efficient desiccant wheel material andnew composite refrigeration and air conditioning systems. Do the main study from thefollowing aspects:(1) Prepared the composite adsorbent by using a solution of different concentrations oflithium chloride、calcium chloride and mixed solution of lithium chloride andcalcium chloride whose molar ratio were1:1to modify the silica. The adsorption capacity, adsorption rate and heat of adsorption of the composite adsorbent wereanalyzed through experiments in different conditions.(2) Take a single channel of the desiccant wheel as the research object, and combinedthe mass and energy conservation equations, the heat transfer model of desiccantwheel with staged-regeneration were established. The performance of the desiccantwheel was studied by using system dehumidification capacity (D) anddehumidification coefficient of performance (DCOP) and calculated byprogramming.(3) Based on the mathematical model of the desiccant wheel with staged-regeneration,the influence of following factors on dehumidifier performance were studied undercertain parameter, such as air inlet temperature, moisture content, regeneration airtemperature and the angle of regeneration zone, etc.(4) An air-conditioning system combined desiccant wheel with staged-regeneration withevaporative cooling was proposed. The performance of the new composite systemwas calculated according to the interior and exterior design parameters. The coolingload, energy consumption for regeneration, COP and exergy efficiency of was comparedwith the general composite air-conditioning system.