Dynamic Characteristic And Simulation Of Natural Wind In Air Conditioning

Modern social structure and fast-paced life means that people have been engaged in working and living indoors. The deterioration of the outdoor environment also increases the time of people staying indoor, which makes the indoor environment has become increasingly important than before: the indoor environment, from the most basic shelter without the need for air conditioning, requires all kinds of equipment and facilities to provide a comfortable environment for people. Air conditioning is one of the most essential equipment, and with the continuing increasing requirements and functionality for the indoor environment, the more functional and effective air-conditioning equipment is constantly needed: indoor equipment from the originally only adjusting the indoor temperature and humidity to lately improving indoor air quality, becomes the one needs to adjust all kinds of conditions of indoor air environment. Moreover, there is growing emphasis on the role of indoor air environment because poor indoor draught can not only make use of air conditioning effect greatly reduced but also makes the persons in the room feeling discomfort and suffering from diseases. The cause of poor indoor draught is that nowadays ventilation equipment just outputs the constant air speed draught, not as soft and changing as natural wind, thus affecting human comfort.Conventional ventilation equipment mainly uses mechanical supply fan, i.e., its air velocity are fixed or act as a fixed mode, which is not ideal. Natural wind, whether the sea, forest or urban wind all can make people feel very relaxed and comfortable. This may because the natural wind has its own unique characteristics. Therefore, if the indoor rooms, which hardly obtain natural wind, can restore the natural-wind like draught, then it will be able to improve the indoor air environment.Current research on natural wind mainly focus on natural wind criteria or the difference between natural wind and constant speed machine wind. However, how to simulate the natural wind indoors is also very important and very practical, because it can greatly improve indoor air environment and improve human comfort so as to achieve energy efficiency. This article analyzed a variety of natural wind and mechanical wind, came up with the simplified and efficient criteria for natural wind; and established a new natural wind simulation model by simulating the characteristics and tested the equipment; finally simplify the model and prototype equipment in order to achieve a simple, low-cost goal:First, according to available literature, the natural wind data were collected at different locations, analyzed data included the average wind speed, turbulence intensity, and the probability distribution of the self-correlation coefficients and other characteristics. We also measured the indoor mechanical wind to summarize the main differences between mechanical wind and natural wind. At the same time, a simplified, efficient indoor natural wind simulation criteria was established.Then, based on the average wind speed, probability distribution, turbulence intensity and self-correlation coefficients, this thesis established a similar Makarov chain model, and used Matlab as the simulation station and then used Labview software to control the drive and fan to output the appropriate air speed. According to the simplified criteria set forth herein, this article tested the new model, and data were collected for another natural wind device.Finally, this thesis used the single-chip technology as the practice of engineering equipment in order to meet the requirements of low cost and acceptable effect. Mainly by reducing the the control parameters of original stochastic optimization mode, this thesis reduced the amount of computation calculation requirement, and set the appropriate time interval to reduce the single-chip’s computing time as needed. Then according to the same criteria, this thesis tested the device leading to good result.