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与导热过程类比,对绝热过程(火积)耗散极值原理表述为:对于具有一定的约束条件并给定热流(热损失)边界条件时,当耗散最大时,则绝热过程最优(平均温差最大);在给定温度边界条件时,(火积)耗散最小,则绝热过程最优(平均热损失率最小).并基于构形理论,以(火积)耗散率最小为优化目标,在给定绝热温度边界条件下,对轧钢加热炉炉壁单层平板和圆柱体绝热层、多层平板绝热层分别进行构形优化,得到三种绝热结构的变厚度绝热层最优构形.结果表明:与等厚度绝热层和热损失率最小的绝热层最优构形相比,(火积)耗散率最小的绝热层最优构形与两者的构形是明显不同的;(火积)耗散率最小的绝热层最优构形能有效降低其平均热损失率,有利于提高其整体绝热性能.将(火积)耗散率极值原理应用到绝热系统的构形优化,有利于拓展(火积)耗散率极值原理的应用范围.
Compared with the thermal conduction process, the extremum dissipation principle of the adiabatic process (FA) is expressed as follows: For the given thermal flow (heat loss) boundary condition, when the dissipation is maximum, the adiabatic process is optimal And the average temperature difference is the largest). At the given temperature boundary conditions, the (heat product) dissipation is the smallest, the adiabatic process is the best (the average heat loss rate is the smallest), and based on the configuration theory, Optimization objectives, given the adiabatic temperature boundary conditions, the rolling furnace wall single-layer flat and cylindrical insulation, multilayer insulation layer were optimized shape, get three kinds of insulation structure of variable thickness insulation best The results show that the optimal configuration of the thermal insulation layer with the lowest thermal mass dissipation ratio is obviously different from the configuration of the two with the same thickness of the thermal insulation layer and the optimal configuration of the thermal insulation layer with the smallest thermal loss rate The optimal configuration of heat insulation layer with the lowest dissipation of heat product can effectively reduce the average heat loss rate and improve the overall thermal insulation performance.The thermal dissipation maximum exergy principle is applied to the structure of thermal insulation system Shape optimization, is conducive to expanding (fire product) the application of the principle of the maximum dissipation rate.