| With the increasing popularity of air conditioning,air conditioning energy consumption has become a problem that can not be ignored.The all air conditioning system can maintain indoor constant humidity,constant temperature,constant oxygen and so on,which can greatly improve the comfort.However,there are still some problems,such as large volume of outdoor units,inconvenient installation for middle and high-rise users and high energy consumption,which restrict the development of all air conditioning system.Therefore,it is of great significance to optimize the outdoor unit of all air conditioner.In this paper,by studying the mathematical model of all air conditioning equipment,according to the mathematical model of each part,the energy consumption simulation model of air conditioning unit is established in the MATLAB/Simulink simulation platform.The main research contents and results are as follows:(1)In the Trnsys simulation software,the annual load model of the building was established.By calling the weather conditions in Qingdao area in the Meteonorm software and importing into the Trnsys,the hourly outdoor temperature of the typical year in Qingdao,the hourly solar radiation,the weather data was imported into Simulation Studio,and the parameters of the building such as window wall ratio,indoor temperature and humidity were also analyzed.The annual hourly load of the building is obtained by setting the internal heat source conditions.By importing the image data into excel,the calculation shows that the maximum cooling load of the building is 8.6 k W,the maximum heating load is 8.43 k W,and the average heating load in heating season is 4.875 k W.In order to further analyze the energy consumption,a typical summer day in Qingdao is selected for specific analysis.The maximum temperature of the day appears at about 12 o'clock,and the minimum temperature appears at about 4 o'clock in the morning.The maximum cooling load of the day is 4.75 k W,and the minimum cooling load is 2.9 k W.(2)According to the mathematical model of each equipment of air conditioning system,such as compressor,condenser,etc.,combined with the control equation of refrigerant,the simulation model of compressor,condenser,evaporator in air conditioning system is established in MATLAB/Simulink,and a complete refrigeration unit model is formed.By calculation,the cooling capacity curve,total energy consumption curve of air conditioning system and energy consumption curve of compressor and fan are obtained.Among them,the energy consumption calculation of the main energy consumption equipment,namely the compressor,shows that the total energy consumption of the compressor is 56.738 k W · h in20 hours on that day.Although the refrigeration capacity meets the demand,the energy consumption is higher.By dividing the compressor into two 1.5P and 3P air-conditioning compressors,the calculation shows that the energy consumption of the compressor after splitting is 24.073 k W · h,which is 57.6% less than that before.At the same time,the original larger outdoor unit is replaced by two smaller outdoor units to facilitate the installation of high-rise household users.(3)The traditional PID control and fuzzy PID control are compared,and in the MATLAB/Simulink simulation platform,the models of two control modes are established and observed in the same scope.The simulation results show that both of them can reach the target temperature quickly without the interference of external factors.But the traditional PID control has some overshoot and oscillation,and the fuzzy PID control has no overshoot,so the control effect is better.In the case of external interference,the fuzzy PID control can recover to the steady state faster,and the overshoot is smaller.Therefore,the fuzzy PID control method can be selected as the temperature control method of all air conditioning system. |
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