Study Of The Technique And Theory Of Phase Change Thermal Storage Applied In Air Conditioning Thermal Storage Equipment

ABSTRACT Energy is the base of pushing the society progress and survive of humankind. Inthe latest 100 years, world energy wastage increased averagely 3﹪ every year, at thesame time the depletion of large quantity energy brought the very serious environmentproblems, for example the weather changing warm, environment destroyed, airpollution etc. All these restrict badly the development of mankind society andeconomic activities. In our country energy and environment condition is also such.Developing the new kinds of energy, increasing the energy utilization efficiency,making use of the technique of saving energy have become the world urgent demand.With the rapid development of economy and the improvement of standard of living,people bring forward the higher request of the environment of work and living, andthe energy consumed about heating, ventilation and air conditioning increases rapidly,so the burthen difference of the peak and vale is further aggrandized. Making use ofthe thermal storage equipment to balance the thermal energy supply on time and thestrength is an economic and viable way. The thermal storage equipment can use thelow valley period of electricity and translate the cheap electric power to the thermalenergy and store the thermal energy. At the high peak period of energy, the thermalenergy stored is released out to reduce the quantity of electricity, and realize" cutpeak and fill vale".These not only save consumedly the running cost of the aircondition, but also alleviate the burden of electric power；And it makes the allotmentof time more reasonable about using electricity. Therefore researching the thermalstorage equipment used in the air conditioning system has important realistic meaningand vast foreground. This study is a part of the subject from Beijing Science Institution. The subject isstudying and manufacturing a new kind of air-conditional thermal storage equipment(subject number: H020520010120). Our subject group develops a new kind of phasechange material. The study object is the PCM and the heat-storing bed filled with the -III-北京工业大学工学硕士学位论文PCM. The study core is: at the request of satisfying the heat-storing quantity, how toshorten the heat charge and discharge time of PCM and increase the heat charge anddischarge efficiency. The influence factors of the heat-storing quantity and the heatcharge and discharge time are divided into two parts: PCM and hot medium. The fluxof the hot medium, the figure of PCM, the physical parameters of PCM, thermalconductivity and heat-transfer coefficient are the important influence factors.Therefore we establish the mathematics model of heat-storing bed and adopt thenumerical method to solve and analysis it and set up the experiment equipment ofthermal storage and discharge and do experiment again and again. By the calculationusing the numerical method and analyzing experiment data, we master the influenceof geometric characteristics of phase change thermal storage equipment and flowcharacteristics of fluid media and physical and chemic characteristics of phase changematerial in thermal storage and discharge process .So we provide reference base fordesigning, optimizing and evaluating the phase change thermal storage equipment.The study method and process is as follows: 1,Analyzing the characteristics of the phase change problem, establishing themathematics model of the phase change problem, comparing and analyzing themethods used to solve the phase change problem, introducing in detail the process ofsolve the phase change problem by using numerical method； 2,Introducing the two-dimensional model, proceeding reasonable simplification,establishing the control equations of the two-dimensional model. Adopting specificheat method and making use of numerical method to solve the control equations,proceeding numerical calculation about the influence factors, analyzing these factors...