| Accelerator driven subcritical system adopts separation-transmutation nuclear fuel cycle technology, while makes full use of nuclear fuel, greatly reduces the volume and toxicity of radioactive waste, it has important significance to realize sustainable development of nuclear power. Therefore, the Chinese Academy of Sciences set up ADS special fund to research key technologies and related basic science issues of ADS by using liquid lead bismuth eutectic and helium as the working fluidS of the primary and secondary circuit. With the support of special fund, the Institute of Engineering Thermalphysics designed LBE-helium Experimental Loop of ADS to study the heat transfer characteristics of working fluids and LBE-helium heat exchanger. This paper developed optimization study of LBE-Helium heat exchanger by numerical simulation, based on LELA, the conclusion can lead the direction of optimum design for ADS heat exchanger.Select reasonable performance evaluation method is the key for heat exchanger optimum design. This paper contrasted several evaluation methods of heat exchanger such as the field synergy theory, the minimum entropy production method, the minimum cost method, the entransy dissipation theory and the JF factor, then studied the relationship of heat transfer performance and pressure drop with entransy dissipation number and the total cost using genetic algorithm. The results showed that, each method has its emphasis and insufficiency, considering the purpose of optimization in this article is to obtain more heat transfer quantity with less energy consumption, JF factor can well balance the relationship between heat transfer coefficient and pressure drop, this paper takes JF factor as the performance evaluation indexe.Carried out numerical simulations for single arch baffle heat exchanger, disk-ring baffle heat exchanger and helical baffle heat exchanger, studied the velocity field, temperature field and pressure field, and get heat exchanger type with the best comprehensive performance or the largest heat-transfer intensity. The results showed that, the comprehensive performance of helical baffle heat exchanger is the best, the heat-transfer intensity of single arch baffle heat exchanger is the largestt, the pressure drop of disk-ring baffle heat exchanger is the biggest of the threes, and the heat transfer coefficient is lower, as the worst heat exchanger type, it should not be commonly used.Carried out numerical simulations for20groups single arch baffle heat exchanger with the baffle cut is0.5D,0.4D,0.3D,0.24D and the baffle spacing is1.5D,1.3D,1D,0.8D,0.6D respectively, studied the influence of different baffle parameters to the flow field, the temperature field, the pressure field, the total heat transfer coefficient and the pressure drop, get the best baffle spacing when the baffle cut is0.2D and the best baffle cut when baffle spacing is1D, fitting the curve of the best baffle cut along with the change of the baffle spacing, guiding the optimization design of heat exchanger. |
PDF Full Text Request