Variable Static Pressure Variable Air Supply Temperature Control Based On PLS Load Forecasting In Air-conditioning System

With the emergence of the energy crisis, China’s urbanization speeding up, thebuilding energy saving research has been paid more and more attention. Central airconditioning system is taken as an important part of a large public buildings. Accordingto statistics, the energy consumption of central air conditioning system is about20%~50%of that of public building. So that its energy saving is particularly important.Variable air volume air-conditioning system is one of the pure air conditioning systems.Compared with constant air volume air conditioning system, it has become theimportant application forms of central air-conditioning in shopping malls,clubs,business apartment, office, and other large public buildings due to its advantagesof flexibility, energy conservation and the realizability of regional temperature control.In actual process, due to the constantly change of the running environment and thesystem load changes, usually system is running in partial load. Accurate prediction ofair conditioning load can guide the implementation of the control strategy and improvethe operation economy of air conditioning system. The control based on load forecast inair conditioning system is one of the research hotspots and trend at present.In this paper variable air volume air-conditioning system of intelligent building andbuilding automation laboratory in Xi’an University of Architecture&Technology istaken as the research object. First of all, the model of static pressure control loop isestablished using the system identification method. And PID control simulation is doneunder Simulink. Secondly, through the comparison and analysis of all kinds of short-term load forecasting methods, the application of partial least squares (PLS)regression analysis method is used to establish the air conditioning system loadforecasting model. Through comparison and analysis, it is concluded that PLS hashigher precision than that of least squares algorithm. Then, the main factors whichimpact air conditioning cooling load and the load value calculation are analyzed. Finally,the system control strategy-Variable Static Pressure Control Variable Supply AirTemperature Control-is determined. The prediction load and the actual load iscalculated and compared on-line using Labview software. The difference value is usedto adjust the set-points of duct pressure and supply air temperature. The experimentshow that the control strategy is feasible and the energy consumption of the system canbe reduced to some extent.