Design And Performance Analysis Of Phase Change Energy Storage Unit Air System

The energy plays an important role in the world's economic development and social progress.If the society wants to achieve sustainable development,on the one hand,we must make full use of natural energy,and actively develop new energy.On the other hand,we must seek the best way of energy saving through scientific and technological innovation to improve energy utilization efficiency.Building energy consumption occupies a certain share in the total energy consumption.Because of the special characteristics communication base station,it becomes the representative of high and heat density of buildings,which heat largely and need constant refrigeration to control indoor temperature environment.Air conditioning system is an important equipment to maintain indoor working environment in communication base station,and its power consumption accounted for about 48%of the total power consumption of the base station.Therefore,energy saving of air conditioning system has an important significance for the communication base station.And it also has a far-reaching influence on reducing building energy consumption.Using phase change energy storage can solve the mismatched energy supply and demand in time and space,optimize energy configuration and improve energy utilization rate.The climate in China is the four distinct seasons,and winter lasts for a long time.There is large temperature difference between day and night in some of the high latitude region in transition season.So it provides good conditions to use of natural cold source.The application of peak and valley price energy-saving technology has been relatively mature in China.Therefore,this paper combines three kinds of energy saving technology which are peak and valley price,natural cold source and phase change energy storage to develop a new ternary two-way phase change energy storage heat transfer model.Because of the special environment of communication base requirements,this paper selects a mixture of capric acid and lauric acid as the organic phase change materials.When decanoic acid content is about 70%,the phase transition temperature of the mixture is 19.8?.The mixture belongs to the room temperature phase change material and the latent heat of phase transformation is 126.6J/g.This stud3y combines phase change energy storage heat transfer model with air conditioning unit,according to the different actual conditions,and analyzes five conditions of phase change energy storage air conditioning unit running in different seasonal conditions.To study this new heat conduction technology of phase change cold storage heat exchange module,firstly,analyze two bidirectional heat transfer heat transfer which includes phase change material and coolant(here refers to the cold air)by numerical simulation method,summarize the rules of storing and releasing cold and determine optimal heat exchange structure and size.Secondly,couple plate heat exchanger with shell-and-tube heat exchanger to propose a new and high efficiency ternary two-way phase change energy storage heat transfer module.Simulate the performance of storing and releasing cold in four different operation conditions to verify the implementation in theory.Finally,put forward the concept of the number of heat transfer unit and use the numerical simulation result of phase change energy storage heat transfer module to confirm the effective heat capacity and verify feasibility.In winter,ternary two-way phase change energy storage equipment can use outdoor cold source instead of air conditioning to keep cool and maintain a constant temperature of communication base station.In summer,it can use valley price to keep the equipment cool and add cold energy to the day room.In transition season,it can use the outdoor cold air and valley price to cool the phase change material at night and release cold energy at day,which can save energy,reduce the capacity of the refrigeration unit,improve the utilization efficiency of the refrigeration unit,make full use of natural cold source,and have great application prospect in energy saving.