Research On Dynamic Temperature Control Strategy And Energy Consumption Analysis Of Central Air Conditioning System

In view of the problems of health and high energy consumption in the control of central air conditioning system based on the thermal comfort theory of steady state environment,the dynamic thermal comfort control strategies have been proposed by domestic and foreign scholars.The strategy can effectively utilize the small regular fluctuation of thermal environment to achieve the unity of comfort and health while satisfying the control of the thermal environment.In this thesis,the quantitative analysis method is used to analyze the main influencing factor of human thermal comfort,and the indoor air temperature is selected as the main parameter of dynamic control by comparing the parameters of steady-state and dynamic thermal comfort.Reasonable temperature control range and change period are determined through a large number of literature research and numerical analysis.On this basis,a mapping function is designed to integrate the trend of outdoor air temperature with indoor thermal environment control,and thus a dynamic temperature control strategy for air conditioning system is proposed.Based on this strategy,the physical model of the room and the thermal comfort field are established in Airpak software and the simulation of the fields of PMV and the PPD are verified with PMV-PPD index.The results show that the air conditioning environment under dynamic temperature control strategy can meet the thermal comfort requirement,in which the index of PMV<|±0.5|and PPD<10%.Based on the experimental platform of VAV air conditioning system in the Institute of Intelligent Architecture,Xi’an University of Architecture and Technology,the mathematical models of energy consumption for main frequency conversion equipment in each subsystem of central air conditioning system are established,and the global optimization objective function of the system is constructed.And the global optimization model is constructed according to the energy transfer of subsystems and physical characteristics of equipment.A genetic algorithm is designed to optimize the energy consumption of air conditioning system on a typical working day in summer.The simulation and optimization results show that the energy saving of dynamic temperature control strategy is up to 15.34%,of which the energy saving of secondary frequency conversion pump is about 16.85%,the energy saving of fans is about 14.16% and 14.43% in air handling unit 1 and unit 2 respectively.