Study On The Simulation Of Comfortable Air-Conditioning Fuzzy Control System

With the development of the national economy and increase of people' s life level, people make an request for the high indoor thermal comfort, however, the control project in which the indoor temperature is unique controlled parameter is not enough. The HVAC system has strong non-1 inear characteristic, and it is difficult to gain the preri.se mathematical model by using the traditional linear control theory, such as PI,PID. Aim at these problems, many scholars have put forward to the method that revises indoor set-temperature value with according to the difference of PMV index and the cHange-rate of its difference, applying fuzzy control. These control methods belong to the feedback control method, the control function of system may be delayed. For the sake of improving control function, the feed front control method based on interfered factors can be adopted. But a control system can' t apply the unique feedfront control, because this request that all interfered factors of system, and this is usually difficult. Combining the feedback control with the feedfront control, the paper put forward to the comfortable air-conditioning fuzzy control system in which the difference of PMV index and the indoor cooling load are input parameters. The paper has simulated the change of indoor thermal environmental parameter and the energy consumption of system under the variety weather circumstances. The results show that the air-conditioning system can be effectively control and the energy consumption of system is economical.The paper analyzed that the environmental factor influences PMV index, and draw these conclusions:ta,tr, a go up that will cause PMV index enlarged; When t, lower human body surface mean temperature, V go up that will cause PMV index reduced; When V, lower 0.1m/s, the wind velocity has no the influence on PMV index. The paper put forward that the influence of the wind velocity to PMV index can be neglected and set up it as a constant (such as 0. 2 m/ s) in the air-conditioning environment with the low wind velocity.The paper, first, established the weather model, the persons flow rate model, the load model, the room model, the cold-water heat exchanger model etc. Second, established the control model based on the difference of PMV index and the indoor cooling load, and established the simulating main program of air-conditioning system. The results of simulation show this control method is on time, and can control PMV index that is satisfied and realize the more economical energy carry of the air-conditioning system.This control method has great feasibility and practical value.