| The promulgation and implementation of the"Outline for the Development of Smart Urban Rail Transit in China’s Urban Rail Transit"in 2020 has clarified the direction for the development of my country’s transportation industry in the post-new crown epidemic era-smart urban rail.The concept of"smart urban rail"was put forward,indicating that the urban subway has a prominent position in my country’s urban rail transportation,and it plays an important role in urban transportation operations.However,the subway ventilation and air-conditioning system has problems such as huge energy consumption and comfort to be improved.In this paper,the energy consumption of Lanzhou subway station under different ventilation and air conditioning scheme conditions is studied by theoretical analysis and calculation and numerical simulation calculation.Combined with thermal comfort evaluation in the study,an air conditioning scheme with better comfort and energy saving performance is obtained.At the same time,the measured and simulated data in the literature"Application of Direct Evaporative Cooling Air-conditioning Technology in Lahore Metro Station"and the research results in this paper were used for mutual verification to ensure that the data deviation rate was within a reasonable range.Based on station load calculation theory,human thermal comfort theory,and air conditioning system comprehensive energy efficiency ratio theory,the composition ratio of the design load in the public area of Lanzhou Metro Station,the influence of different air conditioning schemes on personnel thermal comfort indicators,and the energy saving effects of different air conditioning systems are studied;DeST software and FLUENT software have studied the annual dynamic load of the public area of Lanzhou Metro Station and the energy consumption of different air-conditioning system schemes in summer,the flow field of different air-conditioning system schemes and the extraction of basic physical parameters for related thermal comfort calculations.After the above research,the following conclusions are drawn:(1)The design load calculation of the subway station is the basis of the follow-up research in this paper.In this paper,the total load of the public area of the station is549.20KW by theoretical calculation,the design cold index of the station public area is119.55W/m~2,and the design cold index of the station hall is 75.28W/m~2,the design cold index of the platform is 201.13W/m~2;(2)On the basis of the design load,this paper using DeST software to the public area of the subway station in lanzhou annual load are simulated calculation,the subway ventilation and air conditioning season load value change is not obvious,while the season air-conditioning dynamic load in most of the time did not meet the design cooling load(subway station DeST cooling load simulation results meet the design calculation of cooling load plus or minus 2%of the total time of June,July and August or September total 0.42%),but the public area of the air conditioning season DeST simulation mean cold index(115.41W/m~2)is still account for 96.54%of the design of cold index;(3)The thermal comfort index calculated based on the simulation results of the FLUNT software shows that inside the subway station,the primary return air conditioning system with a supply air temperature difference of 10°C(the average value of the PMV index is 0.679,and passengers are dissatisfied with the thermal and humid environment in the station.9.940%)is more comfortable than the direct evaporative cooling system(the average PMV index is 0.723,and the dissatisfaction of passengers with the hot and humid environment in the station is11.316%);(4)The core content of this paper is to use the DeST software to simulate the energy consumption of different air conditioning schemes.The simulation results show that the direct evaporative cooling scheme has a lower annual energy consumption than the primary return air scheme(annual energy consumption is 468,700 k W·h),and the primary return air system(630,600 k W·h)with the most comfortable air supply temperature difference of 10℃saves34.56%energy.(5)Finally,this article gives suggestions on the selection of the ventilation and air-conditioning system of Lanzhou Metro:(1)Combined analysis of comfort evaluation and energy consumption simulation results,the best air-conditioning solution for Lanzhou Metro public area is a direct evaporative cooling system and a primary return air system with a temperature difference of 10℃between the supply air and the air;(2)From the perspective of energy saving,direct evaporative cooling system is the better air conditioning solution;(3)From the perspective of passenger comfort,a primary return air system with a supply air temperature difference of 10°C is a better air conditioning solution.At the same time,the direct evaporative cooling system can also be used to reduce the blowing sensation and relative humidity to improve passenger comfort.In this paper,a combination of numerical simulation and theoretical analysis is used to study the air-conditioning system in the public area of Lanzhou Metro Station from the perspectives of energy saving and personnel comfort.At the same time,this paper uses published reliable measured and simulated data,theoretical calculation results,and numerical simulation results for mutual verification.The deviation rates of the three data are within a reasonable range,which ensures the reliability of the conclusions.Provide optimization opinions and data support for the selection of subway air-conditioning system represented by Lanzhou area. |
PDF Full Text Request