Design And Development Of Central Air-conditioning Energy-saving Control System

Central air-conditioning system has become a major energy consumer inside the buildings, according to statistics, the central air-conditioning system energy consumption accounts for40%to70%of total building energy consumption. Therefore, we must face this problem in today’s society. The method of load estimation commonly is used in Traditional central air-conditioning system design, and designed with maximum load, And the heat exchange system commonly used constant flow or constant air volume operation mode, resulting in a huge loss of energy and high running costs of building.Against the high energy consumption of central air-conditioning system, The paper analyzes composition of energy consumption, based on the central air conditioning system structure and working principle, and demonstrates the necessity of variable flow and variable air volume operation. The paper analyzes and compares the technical principles of frequency transformation and energy-saving control method. Paper presents a reasonable energy saving solutions separately according to the characteristics of the chilled water system, fan coil systems, cooling water systems and cooling tower fan systemPaper describes the hardware implementation and schematics of energy-saving control system in detail, from the main control board and the manual control panel two aspects, And designs embedded central air-conditioning control system based on STM32microcontroller, implement energy saving through the variable flow control.Paper describes software design and implementation of the energy-saving control system System software includes module machine program and manual control panel program Module machine program achieved the major signal acquisition, logic control and energy-saving control strategy; manual control panel program implement the major human-computer interaction and coordination functions of module machine. The communication between module machine and manual control panel use RS485bus based on Modbus protocol. For the great delay and non-linear of central air conditioning system, predictive control is combined with artificial neural network to achieve the central air-conditioning energy-saving control. Respectively, This paper describes design process of neural network predictive controller in detail from the prediction model and the feedback correction to scroll optimization. And the algorithm is simulated compared to the traditional PID control in Matlab, and get a good control effect and dynamic properties. Finally, The paper provide the method and steps of implementation of the algorithm in the microcontroller.