换热器与系统交互层面下低温多股流流动传热机制与协同设计方法研究

High-efficiency multi-stream energy integration and transmission are the key technology for cryogenic industrial systems to reduce power consumption and increase production. However, the existing thermal design method for multi-stream flow is mainly based on the design experience of two streams, which focuses on the heat transfer enhancement of finned channels at the heat exchanger level but ignores the interaction of multiple steams at the system level and its influence on the overall performance. In order to achieve a design matching between the heat exchanger and system levels to further improve the flow and heat transfer efficiency, this project is devoted to the study on the heat transfer mechanism and collaborative design method of cryogenic multi-stream flow with the coupling influences of multiple levels and factors. It starts from the structural parameters of multilayered finned channels and the actual process conditions of local heat exchange network, respectively, and uses multi-objective thermal-hydraulic optimization and multi-parameter process simulation. Then, the flow and heat transfer characteristics inside multilayered finned channels as well as the influence mechanism of their structural parameters are revealed at the heat exchanger level. Meanwhile, the energy transfer mechanism and energy-flow matching principles of multi-steam flow under the constraints of local heat transfer network are figured out at the system level. Considering the interactive influences of these two levels, collaborative design for the flow and heat transfer of cryogenic multiple streams are carried out, verified and improved by corresponding performance matching experiments. Finally, a collaborative design framework is established for cryogenic multi-stream flow based on the interaction of both heat exchanger and system levels, which provides a theoretical guidance and technical support for similar heat transfer design of multi-stream flow with coupling influences of multiple levels.

高效多股流能量集成与传递是低温工业系统降耗增产的关键技术，但现有流动传热设计方法主要基于两股流设计经验，侧重换热器层面的通道翅片传热强化，而忽略了系统层面多股流体间的相互作用及其对整体性能的影响。为实现换热器与系统层面的设计匹配、进一步提升流动传热效率，本项目专门针对低温多股流开展多层面多因素耦合影响下的流动传热机制及其协同设计方法研究。分别从层叠翅片通道流动传热结构与局部换热网络实际工艺条件出发，以多目标热工水力仿真优化和多参数流动传热过程模拟为手段，揭示换热器层面中层叠通道内的流动传热特性及其结构参数影响机制，探明系统层面中局部换热网络约束下多股流体间的能量迁移机理及能流匹配原则。在此基础上，开展两层面交互影响下的低温多股流体流动传热协同设计及其换热性能匹配实验。最终，构建换热器与系统交互层面下的低温多股流体流动传热协同设计框架，为类似多层面耦合的多股流传热设计提供理论指导与技术支撑。

高效多股流能量集成与传递是低温工业系统降耗增产的关键技术，但现有流动传热设计方法主要基于两股流设计经验，侧重换热器层面的通道翅片传热强化，而忽略了系统层面多股流体间的相互作用及其对整体性能的影响。为实现换热器与系统层面的设计匹配、进一步提升流动传热效率，本项目专门针对低温多股流开展多层面多因素耦合影响下的流动传热机制及其协同设计方法研究。分别从层叠翅片通道流动传热结构与局部换热网络实际工艺条件出发，以多目标热工水力仿真优化和多参数流动传热过程模拟为手段，揭示换热器层面中层叠通道内的流动传热特性及其结构参数影响机制，探明系统层面中局部换热网络约束下多股流体间的能量迁移机理及能流匹配原则。在此基础上，开展两层面交互影响下的低温多股流体流动传热协同设计及其换热性能匹配实验。最终，构建换热器与系统交互层面下的低温多股流体流动传热协同设计框架。项目系统性的解决传统多股流传热计算方法的局限性问题，解决了目前局部换热网络的多股流体流动换热匹配理论缺失问题，解决了换热器与换热系统交互层面的协同优化设计问题。通过理论设计、数值优化、实验验证揭示了层叠通道间低温多股流体的流动传热规律，探明了局部换热网络内多股流热物理场的协同作用机理，针对换热器与换热系统交互层面的多股流协同设计给出了科学解释与理论描述，完善复杂结构下多股流体多因素耦合换热设计的理论体系。项目提出了一种多目标紧凑式换热器综合性能权衡设计方法、提出了一种换热器与换热网络交互层面下低温多股流流动整体优化框架、首次开展了低温多股流换热器及其换热网络匹配及能量回收实验研究等。项目所得结果对于揭示层叠通道间低温多股流体不同工况下的流动传热规律及其协同优化设计机理具有重要意义，可为类似的复杂结构低温多股流换热设计问题提供理论基础与指导依据，在低温工程、石油化工、能源动力等大型工业系统中具有良好的应用前景。