In the viewpoint of heat transfer, heat transport potential capacity and its dissipation are defined based on the essence of heat transport phenomenon. Respectively, their physical meanings are the overall heat transf...In the viewpoint of heat transfer, heat transport potential capacity and its dissipation are defined based on the essence of heat transport phenomenon. Respectively, their physical meanings are the overall heat transfer capa-bility and the dissipation rate of the heat transfer capacity. Then the least dissipation principle of heat transport poten-tial capacity is presented to enhance the heat conduction efficiency in the heat conduction optimization. The principle is, for a conduction process with the constant integral of the thermal conductivity over the region, the optimal distribu-tion of thermal conductivity, which corresponds to the high-est heat conduction efficiency, is characterized by the least dissipation of heat transport potential capacity. Finally the principle is applied to some cases in heat conduction optimi-zation.展开更多
The applicability of the extremum principles of entropy generation and entransy dissipation is studied for heat exchanger optimization. The extremum principle of entransy dissipation gives better optimiza-tion results...The applicability of the extremum principles of entropy generation and entransy dissipation is studied for heat exchanger optimization. The extremum principle of entransy dissipation gives better optimiza-tion results when heat exchanger is only for the purpose of heating and cooling, while the extremum principle of entropy generation is better for the heat exchanger optimization when it works in the Brayton cycle. The two optimization principles are approximately equivalent when the temperature drops of the streams in a heat exchanger are small.展开更多
The optimization approach based on the biological evolution principle is used to con-struct the heat transport paths for volume-to-point problem. The transport paths are constructed by inserting high conductivity mate...The optimization approach based on the biological evolution principle is used to con-struct the heat transport paths for volume-to-point problem. The transport paths are constructed by inserting high conductivity materials in the heat conduction domain where uniform or nonuniform heat sources exist. In the bionic optimization process, the optimal constructs of the high conductiv-ity material are obtained by numerically simulating the evolution and degeneration process ac-cording to the uniformity principle of the temperature gradient. Finally, preserving the features of the optimal constructs, the constructs are regularized for the convenience of engineering manu-facture. The results show that the construct obtained by bionic optimization is approximate to that obtained by the tree-network constructal theory when the heat conduction is enhanced for the do-main with a uniform heat source and high conductivity ratio of the inserting material to the sub-strate, the high conductivity materials are mainly concentrated on the heat outlet for the case with a uniform heat source and low thermal conductivity ratio, and for the case with nonuniform heat sources, the high conductivity material is concentrated in the heat source regions and construacts several highly effective heat transport paths to connect the regions to the outlet.展开更多
文摘In the viewpoint of heat transfer, heat transport potential capacity and its dissipation are defined based on the essence of heat transport phenomenon. Respectively, their physical meanings are the overall heat transfer capa-bility and the dissipation rate of the heat transfer capacity. Then the least dissipation principle of heat transport poten-tial capacity is presented to enhance the heat conduction efficiency in the heat conduction optimization. The principle is, for a conduction process with the constant integral of the thermal conductivity over the region, the optimal distribu-tion of thermal conductivity, which corresponds to the high-est heat conduction efficiency, is characterized by the least dissipation of heat transport potential capacity. Finally the principle is applied to some cases in heat conduction optimi-zation.
基金Supported by Major State Basic Research Development Program of China (Grant No. 2007CB206901)
文摘The applicability of the extremum principles of entropy generation and entransy dissipation is studied for heat exchanger optimization. The extremum principle of entransy dissipation gives better optimiza-tion results when heat exchanger is only for the purpose of heating and cooling, while the extremum principle of entropy generation is better for the heat exchanger optimization when it works in the Brayton cycle. The two optimization principles are approximately equivalent when the temperature drops of the streams in a heat exchanger are small.
基金This work was supported by the National Key Fundamental R&D Program of China (Grant No. G20000263).
文摘The optimization approach based on the biological evolution principle is used to con-struct the heat transport paths for volume-to-point problem. The transport paths are constructed by inserting high conductivity materials in the heat conduction domain where uniform or nonuniform heat sources exist. In the bionic optimization process, the optimal constructs of the high conductiv-ity material are obtained by numerically simulating the evolution and degeneration process ac-cording to the uniformity principle of the temperature gradient. Finally, preserving the features of the optimal constructs, the constructs are regularized for the convenience of engineering manu-facture. The results show that the construct obtained by bionic optimization is approximate to that obtained by the tree-network constructal theory when the heat conduction is enhanced for the do-main with a uniform heat source and high conductivity ratio of the inserting material to the sub-strate, the high conductivity materials are mainly concentrated on the heat outlet for the case with a uniform heat source and low thermal conductivity ratio, and for the case with nonuniform heat sources, the high conductivity material is concentrated in the heat source regions and construacts several highly effective heat transport paths to connect the regions to the outlet.
