Research On Improved Ant Colony Algorithm Applied In The Air Conditioning Chilled Water System

In the information technology industry, economic development going hand in hand with the social and human society, people pay great concern and attention to the resource shortages, environmental degradation and other issues what we are facing with while people increase the request of working and living environment quality. In recent years, when the social progress and ecological environment closely contacts with each other and coordinate development, new building technology industry is constantly improving the traditional building industrial process. Along with intelligent building as a new trend of modern architecture during Chinese sustainable development, the design optimization of air-conditioning system will be an important part.Variable flow air conditioning system is to become the leading role of the air conditioning system, and the chilled water system what is the main part of it, is not only associated with the comfort of indoor temperature, but also is the important factor influencing the energy consumption of the whole system. With the continuous development and more and more complexity of the air conditioning system, the requirement of the control links also becomes higher. However, in the chilled water system, the performance of traditional PID control depends on parameter tuning, the method of which is either easy to get into the local minimum or depends on the object model, so there are some application limitations. As a growing up intelligent algorithm, ant colony algorithm needs no prior knowledge or stringent initial value, and can solve the complex problem well. It has been applied to many practical optimization problems. But there are still many defects such as longing searching, stagnation and no enough of the solution space searching of the basic ant colony algorithm.Chilled water control system in the variable flow air conditioning is introduced in this paper, and is introduced several methods about the supply air temperature control and variable flow control. Combining the advantages and disadvantages of these control methods, it is proposed a variable flow temperature difference-valve opening degree control technology. And using the simulation experiments to validate the control effect, the results show that this control method can greatly accelerate the response speed and significantly improve the control effect. What's more, aiming at the above-mentioned disadvantages of the ant colony algorithm, an improved ant colony algorithm is proposed, which uses an adaptive pheromone evaporation factor. The model of chilled water system related equipment is established. The PID control, ant colony optimizing PID control, and improved ant colony optimizing PID control were applied into the chilled water system respectively. After simulation and comparison, the results show that the PID control designed based on the improved ant colony algorithm has faster optimizing speed and better optimizing accuracy, which effectively improves system performance. Theoretic analysis and the simulation proved the improved ant colony algorithm's validity.