Air Conditioning Fixed Water System Reform To Change The Water System Feasibility Study

Variable flow chilled water system (VWV) is an effective energy-saving measure, which has a smaller size of pipe and equipment than the normal ones for it has considered the dispersing rate of the load in the systems. Furthermore, the problems of large flow and low temperature differential will be solved as a result of the pumps in the VWV system operating in the capacity and head which system actually requires. To solve the problems in the design and operation of constant flow chilled water system, the thesis suggested that the chilled water system could be converted from constant flow to variable flow. In this thesis, the possibility of the conversion, the characteristics of VWV system and the optimized method in the designing of chilled water system were deeply studied.From this paper, a new optimized method and its program in the designing chilled water system were presented, and a scheme to convert a constant flow system to variable flow system was also brought forward. Applying Network Graph Theory into the study of VWV system was given in this thesis, and a program simulating the operation of the chilled water system was written according to this method. Using the program, the thesis studied the status of the chilled water distribution in the system when operating in the practical conditions, and analyzed the performance of the system when adopting different controlling methods of pumps and the chilled water flow in the AHUs (Air Handling Unit) during the course of converting the constant chilled water flow system to variable chilled water flow system.The results show that it is possible to convert the present constant system to variable system technologically. As the reason of the high fist-cost, the economic analysis should be made seriously before the conversion. The larger of the system and load change, the more benefits from the conversion will be gotten and the fewer return years will be required.