The Optimization Of Gas Hydrate Storage Tank And Economic Analysis Of Its Air-Conditioning System

With the development of society and economy, the imbalance between supply and demand of electric power supply is more serious. In this case, the application of cool storage airconditioning technology not only can achieve peak load shifting and balance electricity load, but also can provide some protection to improve the network's safety operation. In the cool storage air-conditioning technology, gas hydrate storage technology is considered one of the most promising storage technology. Compared with other air-conditioning systems, it has many advantages: its transformation temperature between 5?~12?;when it combines with conventional air-conditioning systems, it does not affect the efficiency of the refrigeration unit;the latent heat of cool storage medium is high, and it approaches ice; the heat transfer performance is good; long-term use will not aging etc. Thus, research and application of gas hydrate storage technology has very important significance.Since the storage tank is the main component of storage system, enhancing heat transfer of storage tank helps to improve the heat transfer efficiency of the whole system. Therefore, by optimizing storage tank to improve the heat transfer performance is essential. This paper studies the heat transfer performance of storage tank of gas hydrate storage system. Use fluent software to simulate temperature distribution and phase distribution of storage tank and draw its graph.Various of factors which can affect heat transfer efficiency of storage tank in the cool storage process can be analyzed in detail. The conclusions are drawn as following:(1)By assuming certain simulate conditions, establish a nine-tube three-dimensional model of storage tank. There are many factors which can affect heat transfer efficiency of storage tank.In order to make the research easier, this paper fixes other variables and studies for a variety in the course of studying. By observing the impact on the heat transfer efficiency of storage tank of the change of each factors, optimum conditions can be draw. The influencing factors of this paper studies include coil arrangement(aligned arrangement and staggered arrangement),coil spacing, coil diameter, secondary refrigerant inlet temperature, initial temperature of storage tank.Through the simulation results, the conclusions are listed as follows:1)Coil spacing is a major factor which can affect the heat transfer efficiency of storage tank. The bigger the coil spacing is,the better the heat transfer effect is.And the impact on coil spacing to the two arrangements is the same.2)In the second stage of cool storage process, the temperature of storage tank in aligned arrangement is faster than staggered arrangement. The temperature distribution of storage tank in aligned arrangement is better than staggered arrangement in the cool storage process. So aligned arrangement is better than staggered arrangement.3)Secondary refrigerant inlet temperature is a major factor which can affect the heat transfer efficiency of storage tank. The lower the secondary refrigerant inlet temperature is, the faster temperature of storage tank decreases, the shorter the time required to complete storage is.4)Coil diameter is a major factor which can affect the heat transfer efficiency of storage tank. The larger the coil diameter is, the faster the storage process is, the more uniform the temperature field of storage tank is.5)Initial temperature of storage tank has little influence on the heat transfer efficiency of storage tank.(2)This paper established a model for economic analysis of gas hydrate storage system.Using evaluation(Life Cycle Cost) compares the economics of gas hydrate storage system, ice storage system and conventional air- conditioning system.The economic of gas hydrate storage system is the best.