Performance Analysis And Economic Evaluation Of Air-conditioning System With Chilled Water

In the recent decades, all kinds of buildings are developing rapidly, including various kinds of offices, commercial buildings, residential buildings and so on. As one of the results, the amount of electricity consumption was raised severely. In public buildings, the electricity peak situation was directly intensified by uneven distribution of air conditioning load. In order to alleviate the situation, energy storage technology was used to cut the peak. By this way, cut peak to fill valley could be achieved, and enormous economic benefits could be obtained under TOU power price policy. There are two mainly forms:ice storage and water storage. Chilled water storage has been developed a lot in recent years, with relatively simple control, low investment, and 10% higher refrigeration efficiency rate than ice storage unit.The principle and characteristics of the chilled water storage system, and the design of storage tank was first introduced in this paper. And based on these, the mathematical model and the economy model of the chilled water storage air conditioning system was also described, with using different priority control strategy. This helped to establish the refrigeration unit mathematical model with more appliance and integrity. Several key factors of chilled water storage air conditioning system were put forward, including cold storage rate, operation strategy, and storage temperature. And the optimal rate of cold storage was calculated with MATLAB. The detailed influences on the system with different operation strategies was separately monitored and analyzed. Through the comparison in different operation mode of units load rate and COP, the operation strategy of priority was optimized to make the cooler work more efficiently and steadily. Finally, the economic analysis on operation strategy and cold storage temperature of chilled water storage air conditioning is optimized. The result indicated that the optimized cooler priority operation strategy was proved to be the best form from the aspects both on system performances and economic point. And the storage temperature of chilled water storage system was considered to be vital to the economy of the entire system.In this paper the hourly energy consumption and cost model of the water storage air conditioning system was established, with a purpose of more precise analysis on performances and economic, in order that some reference could be provided on the design and application of chilled water storage system.