The Application Of PHDC Theory In The Connected Large-height Space

At present,the layered air conditioning design which is widely used in railway stations is more energy-efficient than the traditional air conditioning system design.In the peak period of railway passenger during the holidays,passenger waiting hall is especial crowd,high density population cause a sharp increase in the amount of heat dissipating capacity,and the original air conditioning system can not meet the requirement of ventilation cooling no longer and effectively dilute concentration of harmful gases inside the building.Which leads to the deterioration of air quality inside the railway station,and decreases the artificial environment quality,thus it has a serious affect on the comfortable and health of passengers and the station staffs.The application of PHDC technology in this kind of large space buildings like railway station for natural ventilation and cooling,can ease the problem of the sharp increase of person heat dissipating capacity during the peak period of high density passenger crowd,increasing in the cooling load,excessive load for air conditioning equipment,and increase of carbon dioxide concentration in building.PHDC technology as an auxiliary mean of cooling in railway station,and it can improve the air quality and the indoor thermal comfort in the station to a certain extent.Thus it can reduce the cost of air conditioning and refrigeration,and achieve the purpose of energy saving and emission reduction.The main research contents and research methods of this paper are as follows:(1)Established the waiting time GM model based on the statistics of the passenger waiting time distribution gained by field survey in a railway station,and adopted GM model to establish the railway station waiting room passenger assembling calculation model.(2)Established the calculation model of natural ventilation volume in railway station waiting room based on carbon dioxide concentration control.(3)Taken meteorological data of recent thirty years as the basis,and formed each month in typical meteorological year by select average monthly meteorological data in recent ten years,and built typical meteorological year of location of the railway station.(4)Taken the determined method of temperature measurement to measure temperature in the waiting room and outside the railway station on the day.At the same time,conducted a field survey to obtain thermal sensation voting value of different time periods in a day.Carried out waiting room temperature and corresponding thermal sensation voting value TSV in method of linear regression,and obtained the linear equation of TSV-indoor temperature.In the equation,thetemperature of corresponding to the thermal sensation voting value TSV was 0,called waiting room thermal neutral temperature.Calculated the thermal sense vote value TSV corresponding to thermal comfort satisfaction rate which was not less than the percent of 80,and fitted thermal comfort satisfaction rate and waiting room temperature,thus obtained the equation of thermal comfort satisfaction rate-indoor temperature.Carried out average temperature of railway station outside and corresponding thermal neutral temperature in method of linear regression,and obtained waiting room ACM model.(5)Calculated and determined design parameters of PHDC tower,included wind tower evaporative cooling efficiency,air supply temperature,wind tower condensation control parameters,water flow,wind tower air supply acreage,wind tower height.(6)Introduced day and night running mode of railway station which used PHDC technology,and designed system operation control program.Analyzed the impact of PHDC technological transformation on original railway station,and put forward some improvement measures.Evaluated economic benefits,environmental benefits,health benefits,social benefits of railway station which transformed by PHDC technology,found that the technique is feasible and has good application prospects.