摘要随着能源与环境的矛盾日益加剧，节能与环保已经成为一个新的话题。煤炭和石油为我国的经济发展提供了良好的基础，但是大量地燃烧煤炭、石油为我国带来了严重的环境问题。作为全球公认的清洁能源，液化天然气可以很好地解决我国能源与环境的冲突，液化天然气在我国具有很广阔的发展空间。84471

LNG接收站是液化天然气跨国交易运输链上十分重要的一部分，LNG气化器是其中不可或缺的设备。沉浸式LNG气化器既能够承担基负荷，又可以用于调峰，对于我国尤其是北方需要供气的城市具有重大意义。

本文通过查阅了前人对沉浸式LNG气化器的相关研究，针对气化器的换热部分的传热过程进行了理论计算。在计算过程中将换热器的传热分成了管内传热、管外传热、综合传热三部分。文中介绍了液化天然气物性参数的计算方法和管内沸腾传热以便于计算管内传热。在计算管外传热时，对管外的气液两相流的传热计算进行了计算简化。在介绍设计算法后，本文以此为依据设计计算了一个沉浸式LNG气化器，证实了这些理论计算的可行性，为以后的沉浸式LNG气化器设计提供了参考。

毕业论文关键词：沉浸式LNG气化器；理论计算；管内沸腾；两相流与沸腾传热

Abstract With the increasing contradiction between energy and environment, energy saving and environmental protection have become a new topic。 Coal and oil provide a good foundation for China's economic development, but burning a large number of coal and oil has brought serious environmental problems。 Liquefied natural gas, as a clean energyrocognized by the world, can be a good solution to the conflict between China's energy and environment, liquefied natural gas in China's development prospects are very broad。

LNG receiving station is an important part of LNG transportation chain, LNG vaporizer is an indispensable equipment。 Submerged combustion vaporizer can be used for affording the base load and peak shaving, it has great significance for cities in the north which need the supply of LNG。

In this paper, by consulting the previous research on the submerged combustion vaporizer, the heat transfer part of the vaporizer as study object, and the heat transfer problem related to the heat transfer part is calculated theoretically。 In the theoretical calculation, the heat transfer problem of the heat exchanger is pided into three parts, which are heat transfer in the tube, heat transfer outside the tube and comprehensive heat transfer。 In the paper, the calculation method of the physical parameters of the liquefied natural gas and the boiling heat transfer in tube are introduced。 While calculating the heat transfer outside the tube, the calculation of the heat transfer in the gas-liquid two phase flow is simplified。 After introducing the design calculation, this paper, based on the theory,designs and calculated for an submerged combustion vaporizer, confirms the feasibility of these theoretical calculations, and provides a reference for the submerged combustion vaporizer design in the future。

Keywords: submerged combustion vaporizer; theoretical calculation; heat transfer of internal tube; two-phase flow and boiling heat transfer

目  录

第一章  绪论 1

1。1 引言 1

1。2 国内外研究现状 2

1。2。1 国内研究现状 2

1。2。2 国外研究现状 5

1。3 本文研究内容 7

1。4 本论文结构 7

第二章  LNG气化器及浸没燃烧技术综述