Study On Optimal Operation Of Central Air-Conditioning System In Public Building

With the rapid development of Chinese economic, the demand for energy has increased significantly. Energy problems have become increasingly prominent. Building energy efficiency has become a research hotspot. Building energy consumption occupies a large proportion in the total energy consumption. With the popularity of central air-conditioning systems, the ratio of the air-conditioning energy consumption in building energy consumption has increased year by year. Energy consumption of power equipment can't be underestimated owing to differences between the actual status and design status. In order to save energy consumption of air-conditioning system, it is necessary to study the optimal operation. This paper mainly study the operation optimization of central air conditioning system room.This paper through the analysis of the typical meteorological monitoring data, summarizing some public building air conditioning load characteristics, and according to the actual characteristics of central air conditioning system come up with practical energy-saving evaluation indexex. Refrigeration loop end directly produce cooling load, the power equipment mainly is chilled water pump, the control object is the circuit temperature of each branch, pump flow. And the corresponding actuators are the backwater branch motorized valve, chilled water pump frequency converter. Considering the chilled water loop cycle's impact on the backwater temperature feedforward and adjust chilled water pump. Use Fuzzy PID controller to control backwater branch temperature to make pump flow and cooling load in each line is equally allocated, It is established in the MATLAB, adaptive fuzzy PID and conventional PID two models, and by changing the quantization factor and considering disturbance to join in the Simulink,various control response curves are analyzed. So as to provide reference for optimal operation strategy Variable water temperature control of main engine, mainly is about raising evaporating temperature of main engine to realize variable water temperature control and energy-saving, and by setting a higher outlet water temperature of evaporator to realize compressor power consumption reduction. The paper also analyzed the variable water temperature mode affecting the wind plate heat transfer at the end. Water cooling loop's hydraulic power is simple, it is not easy to have hydraulic power disorders and the control is relatively easy. This project adopts the MPC control model, and according to the mathematical model for cooling tower's thermal exchange efficiency, the corresponding water temperature under certain cooling water flow or air volume can be inferred. Complete reasoning computation directly through the upper computer to directly control the actuators. Mathematical model has three parameters to be tested, the parameters' fitting accuracy is key to quality control.Through overall optimization, verify several groups of best working conditions under different load that is, the typical working condition. When monitored outdoor temperatures rise, corresponding load increases, the freezing and cooling water pump's frequency will intelligently switch to typical working conditions under corresponding load and realize variable flow control in different stages. This study on the central air conditioning system optimal operation has reference value for engineering applications.