框架式板式换热器.doc

板式换热器设计与分析摘要 I板式换热器的传热性能与版面的波纹形状、尺寸及版面组合方式都有密切关系。对于任何一种新型结构尺寸板片的传热及阻力特性,都只有通过实验计算测定。对于无相变传热,多数制造商都能提供关联式:对于相变传热,绝大多数的产品,尚不能提供相关的关联式。板式换热器是一种高效紧凑的换热设备,它的应用几乎涉及到所有的工业领域,而且其类型、,焊接型板式换热器的紧凑性,重量轻、换热性能好、初始成本低等优越性已越来越被人们所认识,因此人们纷纷对板式换热器内流动状态和换热机理展开研究。随着 putational Fluid Dynamics) 技术发展日趋成熟,使对流体内部温度场、压力场以及速度场的分布研究变得可行,鉴于此, 本文应用 CFD 软件对人字形波纹板式换热器进行数值模拟,在此基础上又进行了实验研究及实验数据与数值模拟的对比分析。基于简化模型的计算结果难以准确描述换热器内完整的流体流动和换热特性。为此,本文建立与人字形波纹板片完全相同的,含分配区和传热区冷热双流道换热的计算模型,用计算流体力学软件 Fluent6 .3,数值模拟 4组不同名义波纹高度下流体的流动和换热情况。分析流道内速度场和温度场发现,进口分配区对流体流动分布和换热都有显著影响,还将流体在流道内的流动情况详细描述。两侧流体的压降和进出口温差的计算值与实验值的误差小于 6%,较准确地反映了换热器内整体的流动和换热特性,可直接用于研究板式换热器的性能,具有一定的工程实际意义。关键词:板式换热器;热力计算;分析;数值模拟;传热性能;流道状态 Design and analysis of plate heat exchanger ABSTRACT II Plate heat exchanger heat transfer performance of corrugated board shape , size and position are closely related. A new structure for any size of plate heat transfer and pressure drop characteristics are determined only by experimental calculations. For the non-phase-change heat transfer , most manufacturers can provide correlation ; for the phase-change heat transfer , the vast majority of products , yet can not provide the corresponding correlation. Plate heat exchanger isa kind of high pact heat transfer equipment , which involves the application of almost all the industrial fields . In recent years , copper brazing plate heat exchanger pact in size , light in weight , good heat transfer performance , and low operating cost advantages has increasingly been recognized . People also begin the research of fluid flow and heat transfer in plate heat exchangers . With the development of putational Fluid Dynamics)technology, we Call obtain the temperature , pressure and velocity vectors distribution of internal fluid . In this thesis , the author mercial CFD software to simulate chevron corrugated plate heat exchangers . Simulation results based on the simplified model are difficult to predict hydrodynamics and thermal characteristics of plate h