Study On Pre-cooling And Optimized Operation Of Gym Building Air Conditioning System In Cold Area

With the rapid development of the economy,the proportion of energy consumption in the total energy consumption is increasing.How to use existing technology to reduce building energy consumption with improving the efficiency of energy utilization,has become the focus of attention.Gymnasium.as a typical public building with large space,the gymnasium has certain characteristics..That pre-cooling the gymnasium according to the different time period to ensure the comfort of people when entering the stadium and using the day and night temperature difference in the cold area in the reasonable use time,with adopting the night ventilation and cooling storage of the gymnasium to reduce the instantaneous high peak cooling load produced when the personnel enter the next day,can achieve the certain purpose of improving the efficiency of building energy utilization.This research first uses DeST to analyze the dynamic load characteristics of the gymnasium throughout the year.It is found that the annual dynamic distribution of cooling load in Harbin gymnasium has obvious peak.The sensible heat load from the audience and the fresh air cooling load account for about 75% of the total cooling load,and the proportion of the full load operation time of the air conditioning equipment during the whole year is very small,with 80% of the time running at 50% load.This paper studies two types of precooling models for precooling at different use periods of the stadium.One is the pre-cooling model of night ventilation and the other is the pre-cooling model of the refrigeration equipment.The night ventilation precooling model mainly studies the cooling storage process of the enclosure structure.Through the statistics of the meteorological parameters.The ventilation process is simulated to get the cooling storage of the enclosure structure,and the design load of gymnasium air conditioning can be reduced by 9.5% using this cooling storage capacity.The pre-cooling model of the refrigeration equipment is mainly studied in the pre-cooling process of indoor air,and the heat balance model of the room is used to analyze the load and room temperature changes in the operation process of the intermittent air conditioning in the gymnasium,and the heat removal during the pre-cooling period is determined.Finally the pre-cooling scheme with different air supply temperatures is given according to the load.Based on the above two models,Phoenics was used to simulate several different operating conditions,including air pre-cooling process with different supply air temperature,and cooling storage of enclosure structure with night ventilation and the different occupancy rate after cooling storage with night ventilation.The improvement of air pre-cooling process can accelerate the pre-cooling speed,and make the gymnasium reach the use requirement after pre-cooling 0.5h.According to the actual peak load peak cutting requirement,the required pre-cooling supply air temperature is selected.For the different occupancy working conditions of the gymnasium after cooling storage with night ventilation,the delay of the refrigerator equipment and the supply air temperature of 23? for audience are respectively used,and the comparison with the reference working conditions of non cooling storage with night ventilation is made.The results show that the peak value of cold load can be reduced by 12.03% under the occupancy rate of 90% in the worst weather condition.In the process of cooling storage with night ventilation,the mechanical ventilation of the design air conditioning system is adopted,resulting in the higher energy consumption of the fan.Therefore,this gymnasium can reduce the peak of cold load in the process of using cooling storage with mechanical night ventilation only when the occupancy rate is high,so as to reduce the input of equipment to a certain extent,to achieve the economic goal.