The Design And Realization Of Solar Heating Fresh Air System Based On Matlab Simulation

With the background of current social sustainable development, more and more public buildings appears with the characteristics of big area, wide space, high air quality requirement, complex regional application functions, none regional partition, dense personnel with high turnover and etc. For the air conditioning systems in these kinds of buildings, the energy consumptions are great. In the condition of current tense social energy and advocates of renewable use of these resources, this paper researches the modeling and simulation based on solar heating fresh air monitoring system as its hardware platform, in order to compensate the insufficiency of external factors such as weather and seasons, and to reach the aim of flexibility in doing the experiments.The solar heating fresh air monitoring system uses the exchange principle of solar energy - hot water - fresh air, and can achieve the functions of ventilation, exhaust heat recycle and warm fresh air providing in winter. The system makes the warm fresh air to take part in the indoor heating load ability, realizes the renewable energy directly applied in the air conditioning heating system, achieves energy saving.This paper derives from the actual development scientific research project. It based on the CAN bus solar heating fresh air hardware platform, and Matlab/Simulink software environment. According to the law of conservation of energy of the solar heating fresh air monitoring system and its experimental data, the mathematical model of fan coil is designed and realized. With the adding of fuzzy control algorithm, the system can be controlled to provide set fresh air temperature. The result of simulation fairly meets the actual experimental data, proving the applicability of fan coil modeling and the effectiveness of fuzzy control algorithm. In the meantime, the simulation achieves the operation flexibility in actual monitoring and measurement system.For the complex systems, set up models and simulation using the physical characteristics can have great limitations. However, the input and output of signals in the process can always be measured and acquired, and these data reflect the dynamic features of the system. So the information providing by these input/output data can be used to build the system’s mathematical model. This method is called system identification, and the least square method is the widely used measurement way. This paper introduces the least square recursive algorithm. Based on Matlab/Simulink software environment, the estimation parameters and system transfer functions are acquired according to different setting situations. Through the comparison of the simulation output and experimental data, the result proves only little error exist. In conclusion, the transfer functions acquired by least square recursive algorithm can approximate and replace the model built based on its physical property, and the least square method can satisfy the model and its simulation requirement.