Study Of Optimum Design Of Lithium Bromide-Water Refrigerator With Heat-Pipe Driven By Exhaust Heat

Lithium bromide-water refrigerator with heat-pipe is new-style equipment driven by exhaust heat from gas. The traditional high-pressure generator is replaced by heat-pipe generator in the refrigerator .It is through the high efficient heat-pipe exchanger that the heat is transferred to the refrigerator from gas.At present the design of lithium bromide-water refrigerator is still by the ordinary method. There are many parameters must be chosen artificially in the design process. This will not only aggravate the burden of the designer but also can not guarantee the optimum result. Considering the shortage of ordinary design method, a program is compiled and software of the optimum design about the lithium bromide-water refrigerator is made in the dissertation. The equipment is divided into two parts and the optimum models about them are established respectively. One is the model for lithium bromide-water system which take the whole heat-transfer area being the least while the COP being the most as target function, the other is the model about the heat-pipe generator which take the heat transfer efficient being the most as target function. At last the calculation programs are compiled by the complex method in Visual BASIC language.Two groups of refrigerators are worked out on the same design conditions by the optimum software in this dissertation and the simulation software of Nanjing University of Technology. It is showed from the compare between the two groups of design results that the refrigerators which are designed by optimum program have less heat transfer area more COP and their generators have more heat transfer coefficient.And then we compare the heat-transfer area and the COP of the sample refrigerator with the optimized one which has the same refrigeration capacity. It shows from the compare that the optimized refrigerator has less whole heat-transfer area and more COP.It is showed from exergy analysis that the heat-pipe generator is the place where the exergy loss is the most. Therefore, it is very important to describe the gas flow parameters precisely in order to optimize the structure and reduce the exergy loss. Onthe basis of numerical simulation thought, the numerical model of the gas flow in the heat-pipe lithium bromide-water generator is founded in the dissertation and processed by the software of Fluent. At last, the disturbing patterns of pressure, temperature and flow velocity of the gas in the heat-pipe generator are exhibited.The work of this dissertation has actualized the optimum design of the lithium bromide-water refrigerator. All of this has laid a foundation of further popularization of the lithium bromide-water refrigerator with heat-pipe.