The Research And Implement On The Energy-Saving Control Of The Air Handling Units

With the widespread use of air conditioning systems,air conditioning energy consumption issues are also increasingly prominent.According to statistics,building energy consumption accounts for 40% of the country's total energy consumption,and air conditioning energy consumption is a major proportion of building energy consumption.Air handling unit is a major regulator of air conditioning system,therefore,in the energy problem increasingly prominent today,researching an air handling units of high efficiency and energy saving has extremely significant significance.At present air-conditioning works at part load in most time,and the cooling dehumidification of the cooler and the heating of the heater causes energy offset phenomenon,which makes serious energy waste.In addition,due to the features of the large delay,strong coupling and the multiple interference,the traditional control method is difficult to achieve the good control quality.If we could meet the control of the temperature and humidity in the air-conditioned room and minimize the energy consumption of air conditioning systems,it will bring good social benefits.This paper aims to design an energy-saving controller of an air handling unit.Firstly,the control method on air conditioning system was studied,which contains energy optimization and controlling quality.On the one hand,in order to maximize the reduction of energy consumption of air conditioning systems,this paper analyzes an effective way to reduce air conditioning energy consumption,summed up a conclusion that the air conditioning system can reduce the energy consumption by adjusting the value of dew point temperature,the fresh air mixing ratio and output air temperature,and proposed an energy saving optimization control strategy in accordance with the real-time load.On the other hand,in order to achieve good control quality when the air conditioning system is running under the circumstance of big lag,strong coupling and multiple interference,this paper presented a fuzzy self-tuning PID control method,and compared with the traditional PID control algorithm on the Simulink platform.Simulation results showed that the fuzzy self-tuning PID control algorithm is superior to the traditional PID control algorithm in reducing the overshoot and resisting to the interference.Secondly,we designed an air handling unit controller based on STM32f103 microcontroller,electric circuit was designed such as the switch input and output,analog input and output,serial communication and other hardware modules.It can be applied to more similar air conditioning systems.In the aspect of software design,an embedded real-time operating system called uC/OS-II was transplanted to this platform.Based on the platform,a multitasking programming was implemented.The characteristics of multitasking programming makes the program can supply more abundant function which can meet the demand of air conditioning system's protean control function.Finally,each module function was tested,the test results showed that the controller worked well during controlling the air handling units.