Research and Development of High Temperature and High Performance Plate-fin Compact Heat Exchanger with the Purpose of Reducing

在温度高于600 ° C的先进燃料电池或燃气涡轮机植物的开发中，板鳍紧凑热交换器中最严重的问题之一是主要的破碎部分或覆盖板连接到管道的部分，对于实际使用来说并不足够强大，因为热压力。如果要解决这个问题，这个研究的目标是提出这样一个具体的建议，以便在热交换器通道中安装扭曲的磁带，以便通过提供统一的热气体出口温度来减少热压力。一项在方形加热通道上安装了各种扭曲磁带的流动和传热性能的研究，实验性地在300 ° C以下和一个平板上制造精密热交换器及其系统已经设计，性能已经测试过。在1985年，第一，使用了两种正方形和矩形部分的角度通道，流动和传热性能高达500 ° C，实验性地使用了各种宽度的音高比，并用黑色油漆涂层。第二，数字计算是为了获得最佳音高比率分布的磁带安装在热交换器通道中。由于使用扭曲的磁带分布，可以很好地接近光片，在温度场上的实验是由热交换器使用的。一个相当好的协议是在实验性和预测性的价值观之间达成的。第三，另一个破碎的建筑的热交换器已经制造和测试过。对热压力的数值分析也是用实验结果进行比较的。它是由实验展示出来的，也是一个预测，即最大压力在覆盖板附近找到了管道连接的部分。关于提高可用温度限制的这些重要和基本信息已获得的板鳍紧凑型热交换器的可用温度限制

One of the most serious problems in the development of plate-fin compact heat exchangers at temperatures above 600゜C for advanced fuel cell or gas turbine plants, is mainly that brazed parts or the part of cover-plate connected to pipings is not strong enough due to thermal stress for practical use. In order to solve this problem, this study aims to make such a specific proposal as to install twisted tapes in the heat exchanger channels appropriate to decrease thermal stresses by giving uniform heated gas outlet temperature.In 1984, a study of flow and heat transfer performances in s square heated channel installed with various kinds of twisted tape was experimentally made below 300゜C and a plate-fin compact heat exchanger and its system was designed and the performance was tested. In 1985, first, by use of two kinds of channels of square and rectangular section of aspect ratio 2, flow and heat transfer performances up to 500゜C were experimentally obtained with the tapes with various width-pitch ratio and coated by black paint. Secondly, numerical calculations were made to obtain the optimum pitch ratio distribution of tapes installed in the channels of heat exchanger. By use of the twist-pitch distribution of tapes well approximating to the optomum one,experiments on temperature fields were made by use of an heat exchanger. A fairly good agreement was obtained between the experimental and predicted values. Thirdly, the other heat exchanger of brazed construction was made and tested. The numerical analyses of thermal stress were also made to make a comparison with the experimental results. It was shown by the experiment and the prediction that the maximum stress was found near the piping connecting part of the coverplate. Thus important and essential information for elevating the available temperature limit of the plate-fin compact heat exchanger was obtained