Digital Simulation Of Air-conditioning System And Optimal Measuring Point Of Indoor Temperature Research

At present,in the air conditioning system for indoor temperature control field,most of the application is based on the single reading from only one temperature sensor,but the location of most indoor sensors are not appropriate.This seriously affected the judgment and control effect on indoor temperature.And the air conditioning room temperature can be difficult to uniform.If the optimal indoor temperature measurement point has been fund,and based on it the indoor temperature is controlled.The control effect,the indoor temperature non-uniformity and indoor comfort can be effectively improved.Therefore,finding the optimal indoor temperature measuring point is the key to improve the thermal comfort of air-conditioning room.The paper is based on variable air volume air-conditioning experiment system in the intelligent building and building automation laboratory in Xi'an University of Architecture and Technology.The variable air volume air-conditioning simulation system is established,and the optimal indoor temperature measuring point of air-conditioning system is researched in the following.(1)Variable air volume air-conditioning simulation system is established in TRNSYS.Compared with the actual system,results show that the simulation system can work in stable operation and reflect the actual system,which lay the foundation for further study.(2)Combined with the indoor thermal environment measuring point layout proposal of human living conditions and the intrinsic factors of the air-conditioning room,the multi-point displacement are achieved in the air-conditioning room system.The simulation results of the measuring point layout are analysed with FLUENT software.It is found that the diaplacement of measuring point can represent the indoor temperature distribution and can be used for multi-sensor indoor temperature research.(3)The research platform for indoor temperature measuring point was independently developed in this paper.The optimal measuring point of indoor temperature is obtained using the principle of the minimum absolute value of different temperature difference.The optimal measurement points are on the two heights of 0.75 m and 1.1 m.(4)Based on the characteristic of the terminal closure of air conditioning system,with the optimal measuring point of indoor temperature,the PD gain model reference adaptive control is simulated in MATLAB to analyze the indoor temperature with the optimal indoor temperature and non-optimal indoor temperature.It can be seen that the control effect of the optimal measuring point on the indoor temperature is superior to that of the non-optimal measuring point and has better practical application value by observing the deviation of the ideal signal and tracking signal and the controller output and other parameters changes.