Application Research On Optimal Operation Of Air Conditioning Water System

With the improvement of the national quality of living,the proportion of building energy consumption accounting for social total energy consumption is more and more,the energy consumption of air conditioning system accounts for 65% of building energy consumption,and the air conditioning water system as an important part of the air conditioning system,occupying about 70% of the energy consumption of air conditioning system,thus,optimal operation of air conditioning water system is of great significance.At present,the research on optimal operation of air conditioning water system is most based on adjustment of single parameter,or improving operation efficiency of certain equipment.Lack of the research on system level.The purpose of the paper is to seek the effective method for optimal operation from the system level.The main working parts of air conditioning water system include chillers,pumps and cooling towers,according to the practical operation of these equipment,establishing the corresponding mathematical model of these equipment,also studying the control method of different equipment's combined operating,and establishing simulation platform of air conditioning water system by Trnsys.Inlet and outlet temperature of chilled water,inlet and outlet temperature of cooling water,chilled water flow,cooling water flow and air flow are chosen as the control parameters of optimal operation,establishing the energy consumption's objective function of air conditioning water system,determining the constraints of the system operation.Selecting certain office building in Hangzhou for an example,calculating building load by De ST.Four days in cooling season are chosen as typical days for energy saving calculation.Analyzing the factors that affecting energy consumption of chilled water system and cooling water system,the influence law on chilled water system and cooling water system energy consumption of different parameter settings is summarized.Optimal calculation for the objective function of air conditioning water system energy consumption by differential evolution algorithm,making the minimum energy consumption as the goal,optimizing combinations of operation parameters,result showed that the system energy consumption of optimal operation is 6.45% lower than before,provided reference value to actual projects.The paper also study the relationship between wet bulb temperature,load ratio and system energy-saving rate,and the results showed that system energy-saving rate was on the contrary trend with wet bulb temperature and load rate.