Preface

Waste heat refers to the energy to be discarded or discharged after the completion of the process. Some of the waste heat discharge temperatures are very high, some are relatively low, and some are mixed with a large number of dust and pollutants. When the waste heat is discharged into the atmosphere and environment, it will not only cause the waste of energy, but also cause serious pollution to the environment. The relevant law of thermodynamics indicates that there is a certain amount of available energy in the waste heat discharged. How to recover and use this part of available energy, improve the utilization rate of energy, and reduce the pollution of the environment has become an important issue of energy conservation and environmental protection.
     The features of this book are as follows:
    (1) In the relevant references, most of the description and explanation of “waste heat recovery” are concentrated in the “technical scheme” itself, that is, only the system diagram is given, and it is pointed out that it is composed of several components, and the design and calculation of the system, especially the design and calculation of important components or equipment, are not explained basically, which brings difficulties to the manufacture, promotion and application of waste heat recovery equipment. In view of the above situation, this book focuses on the principle and design of waste heat recovery, and focuses on design. The author believes that only by mastering the design calculation method and designing the key equipment, can we really master the technology itself and improve and develop the waste heat recovery system.
    (2) The author of this book has been engaged in teaching and industrial services in the field of energy for a long time, and has participated in the research, development and design of many industrial departments' waste heat recovery projects. The design methods and most examples in this book have the background of industrial application.
    Considering the wide application field of waste heat recovery, the numerous industrial sectors involved, and the continuous emergence of new technologies and schemes, the content of this book still needs to be improved. We hope the publication of this book can provide a little help to the cause of waste heat recovery.

前 言

余热，又称废热，是指在工艺过程完成后准备废弃或排放的能量。余热的排放温度有的很高，有的较低，在排放的余热中，有的夹杂着大量的粉尘和污染物。将余热排向大气和环境中，不但造成了能源的浪费，而且会对环境造成严重的污染。热力学相关定律指出，在排放的余热中都含有一定的可用能。如何回收和利用这部分可利用的能量，提高能源的利用率，同时减轻对环境的污染，已成为节能和环保的重大课题。
   本书的特点如下：
  （1）在相关的参考文献中，对“余热回收”的叙述和讲解，绝大多数都集中在“技术方案”本身，即只给出系统图，指出由几个部件组成，基本上不讲解系统的设计计算，尤其是重要部件或设备的设计计算，这给余热回收设备的制造、推广和应用带来了困难。针对上述情况，本书重点讲述余热回收的原理和设计，而且以设计为主。作者认为，只有掌握了设计计算方法，能自行设计关键设备，才能真正地掌握技术本身，才能对余热回收系统进行改进和开发。
  （2）本书作者曾长期从事能源领域的教学和工业服务，参与过众多工业部门余热回收项目的研究、开发和设计，本书中的设计方法和大多数例题都有工业应用的背景。
  考虑到余热回收的应用领域极其宽广，涉及的工业部门众多，新的技术和方案在不断涌现，本书所涉及的内容还有很多有待提高和完善之处。希望本书的出版能对余热回收事业提供一点微薄的助力。