| With the rapid development of society,the subway,as a convenient and fast transportation mode in urban transportation,plays an indispensable role in urban transportation,but the energy consumption problem brought about by the operation of the subway ventilation and air conditioning system is also becoming more and more significant,according to statistics,the energy consumption of the subway station ventilation and air conditioning system in the entire subway station building energy consumption occupies about40%.Therefore,it is of great significance to explore a more energy-efficient ventilation and air conditioning system solution for subway stations to reduce the energy consumption of subway station ventilation and air conditioning systems.This research paper takes Guangzhou Metro Nancun Station as the research object,analyzes the load characteristics and load composition of the metro station,simulates the annual air-conditioning hour-by-hour cold load of the station through a combination of theoretical analysis,field measurement and numerical simulation,designs a unit test scheme,tests the performance of the magnetic levitation chiller unit and scroll chiller unit,and compares and analyzes the annual energy consumption of three different air-conditioning system schemes for the metro station.Firstly,this paper used SketchUp modeling software to establish the 3D model of the station building,and imported the OpenStudio energy consumption simulation software to simulate the air-conditioning year-round cooling load of this metro station,and gained the year-round distributions of the air-conditioning cooling load of the system.Secondly,the performance testing scheme of two direct-expansion units(magnetic levitation unit and scroll unit)was designed,and the operating performance of direct-expansion air conditioning units and related influencing factors were studied through performance testing,and the influence of compressor speed,fan speed and inlet air wet bulb temperature on unit performance was discussed through single-variable performance testing,and the performance of the units under different loads was tested.In addition,based on the laboratory test data,a chiller unit performance measurement model is developed and a SPSS software is used to perform a multiple linear regression on the model to derive a linear regression equivalent,which serves as a point of reference for examining the cooling rate and power efficiency of the unit.Finally,according to the station design manual,the conventional all-air primary return air conditioning system of the subway station was simulated by EnergyPlus software for annual energy consumption,while the evaporative condensing air conditioning system and the direct expansion air conditioning system were compared with the all-air air conditioning system for annual energy consumption analysis,and the results showed that the evaporative condensing air conditioning system saved 14.55% energy relative to the all-air system,with Certain energy-saving;direct expansion air conditioning system relative to the all-air system,energy saving 19.22%,energy-saving effect is more obvious.Therefore,from the perspective of economy and applicability,In subway stations in hot summer and warm winter areas,direct expansion ventilation and air conditioning system is recommended.Maglev type is used for cooling and air conditioning units of large system,scroll type/direct expansion type(water-cooled screw machine,VRV machine)is used for air-conditioning units of small system. |
