板壳式换热器壳程流动与传热性能的数值模拟

The Numerical Simulation of the Flow and Heat Transfer on the Shell Side of the Plate and Shell Heat Exchanger

板壳式换热器作为一种新型高效紧凑式换热设备,因其换热效率高、压降低、节省占地面积、节约工程及设备安装费用、节省装置操作费用等优点,被广泛应用于炼油、化工、制冷等领域。本文以一种板壳式换热器为对象研究,建立了人字形板片的单流道物理模型并利用数值模拟软件模拟了波纹高度的变化引起的模型流场、速度场、压力场、温度场的变化情况,通过对湍动能、摩擦系数和传热因子的分析,研究了波纹高度的变化对于板壳式换热器流动和传热性能的影响。分析得到:波纹高度的变化造成了内部流体流动状态的变化,随着波纹高度的增大,流体的流动状态由曲折流逐渐转变为十字交叉流,波纹高度越低,湍动能越好,阻力性能越好,但是传热性能变差。模拟表明波纹高度对板壳式换热器的流动和传热性能具有较大的影响,是板壳式换热器优化设计的重要方向。

As a new type of high efficiency and compact heat exchange equipment, plate and shell heat ex-changer is widely used in oil refining, chemical industry, refrigeration and other fields because of its high heat exchange efficiency, low pressure, saving floor area, saving engineering and equipment installation costs, saving device operation costs and other advantages. In this paper, a single channel physical model of herringbone plate is established for a plate and shell heat exchanger. The flow field, velocity field, pressure field and temperature field caused by the change of corrugated height are simulated by numerical simulation software. The influence of corrugation height on the flow and heat transfer performance of plate and shell heat exchanger was studied. The results show that: the change of ripple height causes the change of internal fluid flow state. With the increase of ripple height, the flow state of fluid gradually changes from zigzag flow to cross flow. The lower the ripple height is, the better the turbulent kinetic energy is, the better the resistance performance is, but the heat transfer performance becomes worse. The simulation results show that the height of corrugation has a great influence on the flow and heat transfer performance of plate and shell heat exchanger, which is an important direction for the optimization design of plate and shell heat exchanger.