Study On The PH Control Of Circulating Cooling Water Of Central Air-conditioning

With the improvement of people’s living standards, the central air-conditioning is playing a more and more important role in people’s life. The number of air-conditioning is also growing faster. But the air-conditioning have a lot of problems due to its circulating cooling water and these problems are gradually attracting people’s attention. These problems are scaling, corrosion and biological sludge, and have a great influence to the air-conditioning. The scaling means that lower energy exchange, the more electric using and the decrease of the temperature control effect. The life of the circulating cooling water tunnel will fall down, and the more dirty water will be discharged which will cause the pollution to the environment, due to the corrosion; The circulating cooling water tunnel may be plugged because of the biological sludge and increase the degree of scaling and corrosion. The p H value of the circulating cooling water of central air-conditioning is one of the most important factors to influence the scaling and corrosion. If we can control the p H value in designed range, it will solve these problems. Therefore, this paper mainly completed the following work.First of all, this paper introduces the background and the significance of dealing with circulating cooling water of central air-conditioning. It is very important to control the p H value of circulating cooling water. And it has made the detailed elaboration about the present situation of control the p H value of circulating cooling water in central air conditioning at home and abroad, gives the scheme of the p H value control.Secondly, this paper gives the working principles and the composition of the central air conditioning system in detail, and it also discusses some parameters of circulating cooling water quality control, focuses the main attention on the problems that existing in the circulating cooling water of central air-conditioning and gives the reasons for the formation of these questions. The paper analyses the reasons why p H value is difficult to control. Combining the advantages of fuzzy control system, and it describes the fuzzy control system structure, classification, designing principles and optimization methods, selects the method that using the improved cuckoo search algorithm to optimize the parameters of membership functions of fuzzy control algorithm to realize the circulating cooling water p H value controlling. Through the simulation and analysis of test functions, the cuckoo algorithm has a better searching performance, and the fuzzy controller can achieve better parameters optimization.Finally, the article introduces the controlling box for the central air-conditioning circulating cooling water to control the p H value, and gives the design principles and procedure of the key function modules, then combines the control algorithm with the hardware design to apply to the actual projects. Through the testing, we found that the designing can control the p H value in the designed range. It also tells that this work is feasibility and effective.