Research On Real-time Energy-saving And Comfort Control Method Of Air Conditioning System Based Onthermal Comfort Index

Thermal comfort research results show that the factors affecting human thermal comfort include air temperature,relative humidity,mean radiant temperature,air velocity,clothing insulation and body metabolic rate.Human body has the same thermal sensation no matter how the combinations of indoor therml environment parameters change as long as they achieve the same comfort index value.However,their corresponding air conditioning energy consumptions are not the same.Under the condition that the human body is in a state of thermal comfort,the indoor therml environment parameters combination which achieve the minimum energy consumption of the air conditioning system is called the optimal parameters combination.The optimal parameters combination is different for different buildings,air conditioning systems and meteorological parameters.Due to the internal and external disturbance of the room are constantly changing,the optimal parameters combination is also changing,so the comfort and energy saving control process should be a dynamic process.Because of the relationship between thermal environment parameters and energy consumption of air conditioner is very complicated,it is hard to build an accurate mathematical model,and the versatility of different types of building and air conditioning system is not strong,so this paper choose the complex method whose search direction can be determined only by comparing the objective function value and functional equation is unnecessary.Based on the real-time measurement of thermal environment and air conditioning system energy consumption,the optimal parameters combination can be solved at different times.The main research contents of this paper are:1)the feasibility of real-time energy-saving and comfort control by complex method.;2)the comfort,energy-saving and real-time performance of this control method.This paper chooses PMV index as the thermal comfort index which has a more mature theoretical basis and practical test.Utilize MATLAB software to compile PMV calculation program and analyze the effects of six parameters on PMV by orthogonal test.Then,this paper establish a composite air conditioning system with radiant floor floor panel system and all-air system,utilize MATLAB software to compile the complex method optimization program and discuss the control scheme.After that,this paper study the lag time of the action of the air conditioning system influencing the thermal environment parameters and PMV index by theorctical analysis,which analyzes the adaptability of air conditioning system delay and real-time control to verify the feasibility of this method.Finanly,the hourly optimal parameters combination of model room is solved according to the control principle.The reluts shows that the influence degree of these six factors affecting human thermal comfort from large to small is followed by body metabolic rate,air temperature,clothing insulation,mean radiant temperature,air velocity,relative humidity.By analyzing the model of office building in hot summer and cold winter area,we find the speed of each type of air conditioning system changes the working area thermal environment parameters is fast.Therefore,the air conditioning systems can be close to the optimal parameters combination of operation,which verify the feasibility of this method.By solving the model’s summer typical day hourly optimal parameters combination and winter typical day optimal parameters combination,we find that under the same comfort condition,this control method can achieve 7%-17%energy saving ratio campared with 26℃ constant temperature control,and the optimal parameters combination can be achieved by 4-14 iterations which can close to the optimum point qiuckly.Therefore this method not only can take comfort and energy saving,but also has good real-time performance.