Research On Design And Energy Consumption Of Multi-split Heat Pipe System In Metro Station Equipment Room

With the rapid development of China’s subway in recent years,it is estimated that the number of kilometers in the future will reach 13,385 kilometers,and the annual power consumption will reach 40 billion k W.h.It will account for more than5%of the total national power consumption in the future.Energy saving and emission reduction of the subway is imperative.The ventilation and air conditioning system accounts for a large proportion of the total energy consumption of the subway station.The little system is composed of the equipment rooms and equipment management rooms.The equipment rooms belong to a place with high heat density.The traditional ventilation and air conditioning system adopts all-air system to dissipate heat.The energy consumption of the fan is large,and the air volume and cooling capacity of the terminal room are difficult to dynamically adjust,thus there is room for optimization and improvement.In response to these problems,this paper takes the little system as the main research object,establishes a water-cooled multi-split heat pipe system for subway ventilation and air conditioning,and makes an in-depth analysis of the system’s energy saving and applicability.First of all,on-site measurement of equipment room and water system in a typical subway station was conducted.According to the test of the air volume and return air enthalpy of each equipment room,the load characteristics of the room was analysed.The real measurement of the chiller and air handling units were conducted to analyse the energy consumption.All of these data can provide data reference for the design of the multi-heat heat pipe system late.Secondly,using Trnsys software to simulate the traditional ventilation and air conditioning system and multi-split heat pipe system.The accuracy of the model was verified based on the measured data.The heat exchange characteristics of water-cooled and air-cooled multi-split heat pipes were analyzed separately,and the energy-saving effect under different control modes was studied.Finally,the application of multi-split heat pipe system is extended.Typical cities in different climate regions are selected as the simulation objects,and the economics and adaptability of the multi-pipe heat pipe system for subway in different climate areas were analyzed.The study found that comparing the annual operation energy consumption of the traditional ventilation and air conditioning system and the multi-split heat pipe system,the energy saving rate is about 22.3%.The maximum energy saving effect can be obtained through the simulation control of the water-cooled multi-split heat pipe system.The use of air-cooled multi-split heat pipe system to realize the heat recovery technology of the equipment management room.The temperature of the equipment management room can be stabilized between19.8～22.8~oC.In addition,the simulation of the multi-split heat pipe system in different climate zones showed that the energy-saving effects are ranked from high to low:Guangzhou,Shanghai,Chengdu and Kunming.