Design And Energy Saving Anaylsis On The Air-conditioner With Latent Heat Thermal Storage

The consumption in communication network has been highly increased with the development of the Internet.And it becomes more meaningful to save energy in improving cooling technologies in communication base station while the energy consumption of air-conditioning system occupies an important position,more than 45%,in the total energy consumption.Most studies already made are concentrated on the direct use of the natural cold source,but the efficiency is not good because the intermittence and the uncertainty of the natural cold source made a obstacle for removing the constantly producing heat of the base station.But the technique of latent heat thermal storage could increase the using efficiency and extend the effective time for it's high thermal storage density and low temperature change.Firstly,this paper made simulations of the full-year load of air-conditioner in communication base station in different areas on DeST.It draws the conclusion that the major load of the air-conditioner comes from the devices in the base station.Meanwhile,it made the selection of phase change materials,the heat exchanger of the thermal storage unit and surface air cooler in air conditioning unit with latent heat thermal storage according to the characteristics of the full-year load.Secondly,the paper made a mathematical model of the surface air cooler,and then validated it's accuracy with experiment data in other papers.The margin of error of the cooling load,air supply temperature and the cooling water outlet temperature in the vary-flow experiment is 1.66%,0.78%,1.23%,respectively.And in the vary-air volume experiment is 0.98%,1.50%,0.16%,respectively.Analyzis have been made about how the operational parameter and the structural parameter of the surface air cooler would influence the efficiency.Lastly,the paper also made a heat transfer model of latent heat thermal storage slab and validated with experiment.Other analysis about how the operational andstructural parameters and the thermal characteristics of the phase-changing material would influence the efficiency of heat transfer with phase-changing.Finally,made model of efficiency of the phase-changing air conditioning unit by coupling the heat transfer of surface air cooler and the latent heat thermal storage unit,and then analyzed the effect that the inlet air temperature,the air volume and the cooling water flow would make to EER in air conditioning unit with latent heat thermal storage in thermal storage mode.The potential of energy saving of the unit based on EER and the amount of electric energy has been made compared to traditional air-conditioner.The full-year EER of the unit in Guangzhou,Changsha,Kunming,Beijing,Harbin is 4.76,6.17,18.25,6,79,10.05,respectively,and it' s electric power saving is 2614 kW h,3167 kW h,5251 kW·h,2920 kW h,2695 kW h,respectively.