Research The Operation Optimization Of Combined Air Handling Unit Based On Ice Storage System

With the popularity of air conditioning and refrigeration technology,energy consumption of air-conditioning system is becoming prominent increasingly.According to statistics,air conditioning energy consumption accounts for 20% of the country’s total energy consumption.Air handling units is the main device of the air conditioning temperature and humidity control system.The cooling and dehumidification of cooler and the reheating of the heat causes the phenomenon of hot load and cold load offsetting during the process of the air handling unit.How to reduce energy consumption of air conditioning systems under the room comfort be satisfied is becoming a research hot spot.Ice storage system has the characteristic that the peak load can be transferred to valley,and the power load can be balanced,lots of operating cost can be saved,and ice storage can be applied in a lager number of the architecture such as office building,stadiums and so on.Lots of research are studied for the air handling units and ice storage systems in domestic and overseas.But the research of combing the two devices is not enough.In this paper,the operation optimization of air handling unit based on ice storage system is studied,to discuss the relationship between room comfort,system energy and system operation costs.The specific work is as follows:(1)On the basis of analyzing the principle of modular air handling units,the mathematical model of air condition temperature and humidity control system was established,and the influence of control variables on room temperature and humidity were analyzed.Laid the foundation for the following operation optimization.(2)On the basis of analyzing the the principle of modular ice storage system,the system configuration,operation mode,control strategy,and the optimization control model of the ice storage air-conditioning system were studied.Under summer conditions,using the strategy of optimizing control for a specific ice storage air conditioning system,it is concluded that the optimal distribution of the ice storage tank and refrigeration unit in a typical summer design day.(3)The control precision target function was established according to the comfort model.The energy consumption cost objective function was established on the basis of the allocation proportion of the cooling load between ice storage tank and refrigeration.The optimal operation objective function of room temperature and humidity control accuracy and energy consumption were established,the simultaneous solution methods were used to transfer the differential and algebraic optimization problems(DAOPs)into nonlinear programming problem to solve.(4)MATLAB and GAMS software were used for simulation,the three following conclusions were drawn: 1,the calculation results showed that under the room comfort tolerance,the system canachieve more than 13% of energy saving effect under permitted indoor temperature tracking error of0.81 ?c,permitted indoor humidity tracking error of 0.79 g/ kg.2,taking the important influence of electricity price and the external environment to ice storage air-conditioning system operation optimization into account,a strategy of dynamically adjusting the weight of objective function was proposed,the results showed that the strategy reduced the system energy consumption by4.3%further.3,The operation optimization method of summer operating conditions was used to discuss the operation optimization of ice storage air-conditioning system in other different seasons.The results showed that this method can save much energy also in other different seasons,and because of the ice tank,energy-saving cost-effective was achieved in other seasons is better than that in summer conditions.This study is of great significance to energy saving optimization of ice storage air conditioning system.