预应力固定管板换热器预变形与应力特性的数值分析

Numerical analysis of pre-deformation & stress of fixed tube sheet exchanger

为了实施预应力换热器技术,对预变形下固定管板式换热器中变形相互约束的构件之间所产生的温差应力与变形分布特性进行了数值研究。借鉴"分段建模,整体综合"的换热器流体力学与传热的数值模拟新方法,利用CFD得到换热器温度场并作为ANSYS结构分析边界条件,采用预拉伸单元进行预变形量的施加与控制,从而获得了热-结构耦合分析结果。数值模拟结果与实验数据吻合得很好,说明所采用的研究方法是合理和可行的。此外,实验和数值分析结果均证实,通过合理地施加和控制预变形量,可以有效缓解和协调固定管板换热器在运行中各构件(管板、壳体、管束)之间的变形约束,从而创造良好的运行环境,最终提高换热器的运行可靠性和使用寿命。

To implement the pre-stressed heat exchanger technology, numerical simulation of the thermal stress between the mutual restraint components and the deformation distribution under pre-deformation in the fixed tube sheet heat exchanger was performed. The new numerical simulation method named ＂Simulation in subsections, integration of the whole＂, and CFD software to get the heat exchanger temperature distribution as a boundary condition for structural analysis in ANSYS. Pre-tension element to impose and control the amount of pre-deformation. The result of thermal-structure coupled analysis was obtained. The research methods were reasonable and feasible, because the simulation results agreed with experimental data very well. In addition, the experimental results and numerical analysis confirmed that by rationally imposing and controlling the amount of predeformation, the restraint between components （plates, shells, tube bundles） of fixed tubes heat exchanger in operation can be effectively alleviated and coordinated to create a good running environment and ultimately improve the operation reliability and service life of heat exchanger.