Application Research Of Cross-flow Open Heat Source Tower Heat Pump System In Railway Station Building

In recent years,China's economy has developed rapidly,boosting the progress of the transportation industry.China's high-speed rail operation ranks first in the world.Such a large-scale railway operation has created many railway station buildings of different sizes.As an important supporting facility for railways,people have high requirements for their internal comfort,but this cannot be achieved by sacrificing more energy.Therefore,research and design of more energy-efficient railway station cold and heat sources has become a topic of concern.The heat source tower heat pump technology is designed according to the unique climatic conditions in the middle and lower reaches of the Yangtze River in China.The area is cold and humid in winter,but the outdoor dry bulb temperature can still be maintained above zero.Therefore,a large number of low-grade heat sources existing in the outdoor ambient air can be used by the heat source tower.These low-grade heat sources are secondary to solar energy and belong to renewable energy sources.The heat source tower heat pump system system is relatively simple in design,strong in applicability,multi-purpose in one machine,stable in operation,and remarkable in energy saving effect.However,at present,the technology is in the development stage,and the application of energy-saving in the large-space railway station has yet to be verified.This paper has carried out a series of research on this issue.Firstly,this paper expounds the working principle of the open heat source tower heat pump system,analyzes the heat and mass exchange theory in the heat source tower,and establishes the heat exchange model of the cross-flow open heat source tower based on this,and uses MATLAB to solve the numerical problem.In order to verify the accuracy of the model,this paper conducted a field test.The results show that the deviation of each parameter is basically within ±10% and has high accuracy.Then,using the established mathematical model,the heat and mass transfer characteristics of the cross-flow open heat source tower under winter heating conditions were studied.Then,the load characteristics of railway station buildings in special large space buildings are summarized.This paper expounds the theoretical basis of TRNSYS building model,and builds a TRNSYS building model for the railway house of Chengdu east railway station,and simulates the annual building load.Based on the annual building load,the cold and heat source scheme is designed,and the TRNSYS model is established for each cold and heat source scheme.The models are simulated and the results are compared.The results show that the system energy consumption of the open heat source tower heat pump system is 19.78% lower than that of the chiller + gas boiler in terms of annual energy consumption,which is 2.55% higher than the ground source heat pump system.However,considering that the initial investment of the heat source tower heat pump unit is about 50% less than that of the ground source heat pump,the heat source tower heat pump unit is still the best choice for the Chengdu East Railway Station.Finally,based on the traditional operation strategy optimization scheme of the heat pump system,the optimal optimization strategy is given by selecting different typical load days and comparing the time-by-time power consumption of different strategies.At the same time,the control strategy of solution regeneration was optimized.