外文翻译-换热器的分类及其应用.docx

南华大学机械学院毕业设计说明书8、英语翻译The use and introduction of the heat exchangerA heat exchanger is a device built for efficient heat transfer from one medium to another, whether the media are separated by a solid wall so that they never mix, or the media are in direct contact. They are widely used in space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, and natural gas processing. One common example of a heat exchanger is the radiator in a car, in which the heat source, being a hot engine-cooling fluid, water, transfers heat to air flowing through the radiator . Heat exchangers may be classified according to their flow arrangement. In parallel-flow heat exchangers, the two fluids enter the exchanger at the same end, and travel in parallel to one another to the other side. In counter-flow heat exchangers the fluids enter the exchanger from opposite ends. The counter current design is most efficient, in that it can transfer the most heat from the heat (transfer) medium. See countercurrent exchange. In a cross-flow heat exchanger, the fluids travel roughly perpendicular to one another through the exchanger.For efficiency, heat exchangers are designed to maximize the surface area of the wall between the two fluids, while minimizing resistance to fluid flow through the exchanger. The exchangers performance can also be affected by the addition of fins or corrugations in one or both directions, which increase surface area and may channel fluid flow or induce turbulence.The driving temperature across the heat transfer surface varies with position, but an appropriate mean temperature can be defined. In most simple systems this is the log mean temperature difference (LMTD). Sometimes direct knowledge of the LMTD is not available and the NTU method is used.Phase-change heat exchangersTypical kettle reboiler used for industrial distillation towersTypical water-cooled surface condenserIn addition to heating up or cooling down fluids in just a single phase, heat exchangers can be used either to heat a liquid to evaporate (or boil) it or used as condensers to cool a vapor and condense it to a liquid. In chemical plants and refineries, reboilers used to heat incoming feed for distillation towers are often heat exchangers. Distillation set-ups typically use condensers to condense distillate vapors back into liquid.Power plants which have steam-driven turbines commonly use heat exchangers to boil water into steam. Heat exchangers or similar units for producing steam from water are often called boilers or steam generators.In the nuclear power plants called pressurized water reactors, special large heat exchangers which pass heat from the primary (reactor plant) system to the secondary (steam plant) system, producing steam from water in the process, are called steam generators. All fossil-fueled and nuclear power plants using steam-driven turbines have surface condensers to convert the exhaust steam from the turbines into condensate (water) for re-use.In order to conserve energy and cooling capacity in chemical and other plants, regenerative heat exchangers can be used to transfer heat from one stream that needs to be cooled to another stream that needs to be heated, such as distillate cooling and reboiler feed pre-heating.This term can also refer to heat exchangers that contain a material within their structure that has a change of phase. This is usually a solid to liquid phase due to the small volume difference between these states. This change of phase effectively acts as a buffer because it occurs at a constant temperature but still allows for the heat exchanger to accept additional heat. One example where this has been investigated is for use in high power aircraft electronicsDynamic scraped surface heat exchangerAnother type of heat exchanger is called dynamic heat exchanger or scraped-surface heat exchanger. This is mainly used for heating or cooling with high-viscosity products, crystallization processes, evaporation and high-fouling applications. Long running times are achieved due to the continuous scraping of the surface, thus avoiding fouling and achieving a sustainable heat transfer rate during the process.The formula used for this will be Q=A*U*LMTD, whereby Q= heat transfer rate.Fluid heat exchangersThis is a heat exchanger with a gas passing upwards through a shower of fluid (often water), and the fluid is then taken elsewhere before being cooled. This is commonly used for cooling gases whilst also removing certain impurities, thus solving two problems at once. It is widely used in espresso machines as an energy-saving method of cooling super-heated water to be used in the extraction of espresso.Plate Fin heat exchangerThis type heat exchanger uses sandwiched passages containing fins to increase the effectivity of the unit. The designs include crossflow and counterflow coupled with various fin configurations such as straight fins, offset fins and wavy fins.Adiabatic wheel heat exchangerA fourth type of heat exchanger uses an intermediate fluid or solid store to hold heat, which is then moved to the other side of the heat exchanger to be released. Two examples of this are adiabatic wheels, which consist of a large wheel with fine threads rotating through the hot and cold fluids, and fluid heat exchangers. This type is used when it is acceptable for a small amount of mixing to occur between the two streams. See also: Air preheater.Regenerative heat exchangerA third type of heat exchanger is the regenerative heat exchanger. In this, the heat (heat medium) from a process is used to warm the fluids to be used in the process, and the same type of fluid is used either side of the heat exchanger (these heat exchangers can be either plate-and-frame or shell-and-tube construction). These exchangers are used only for gases and not for liquids. The major factor for this is the heat capacity of the heat transfer matrix. Also see: Countercurrent exchange, Regenerator, EconomizerPlate heat exchangerAnother type of heat exchanger is the plate heat exchanger. One is composed of multiple, thin, slightly-separated plates that have very large surface areas and fluid flow passages for heat transfer. This stacked-plate arrangement can be more effective, in a given space, than the shell and tube heat exchanger. Advances in gasket and brazing technology have made the plate-type heat exchanger increasingly practical. In HVAC applications, large heat exchangers of this type are called plate-and-frame; when used in open loops, these heat exchangers are normally of the gasketed type to allow periodic disassembly, cleaning, and inspection. There are many types of permanently-bonded plate heat exchangers, such as dip-brazed and vacuum-brazed plate varieties, and they are often specified for closed-loop applications such as refrigeration. Plate heat exchangers also differ in the types of plates that are used, and in the configurations of those plates. Some plates may be stamped with chevron or other patterns, where others may have machined fins and/or grooves.换热器的分类及其应用 换热器是一种装置内置高效换热从一个中等至另一个，无论是媒体分隔了坚实的墙，使他们永远组合，或新闻媒体直接接触。 1 他们被广泛用于供暖 ， 制冷 ， 空调 ， 发电厂 ， 化肥厂 ， 石化厂 ， 炼油厂和天然气处理 。 换热器可分为根据其流安排。 平行流换热器，两个流体进入换热器在同样的目的，和旅行中的彼此平行的另一边。 在逆流换热器的液体进入热交换器从对面的目的。 目前设计的柜台是最有效的，因为它可以转移最热热火（转让）的媒介。 在横流式换热器，流体旅行大约垂直于一个通过热交换器。 为了提高效率，热交换器的设计，最大限度地面积之间的墙壁两个流体，同时最大限度地减少阻力流体通过换热器。 该交换机的性能也会受到影响，增加了鳍或波纹中的一个或两个方向，从而增加表面积和可能的渠道流体流动或诱使动荡。 驾驶温度在传热表面不同位置，但一个适当的平均气温可界定。 在最简单的系统，这是记录平均温差 （对数平均温差） 。 有时直接了解对数平均温差不提供和台大方法是使用。 edit Phase-change heat exchangers相变式换热器Typical kettle reboiler used for industrial distillation towers典型釜沸用于工业蒸馏塔 Typical water-cooled surface condenser典型的水冷式表面冷凝器 In addition to heating up or cooling down fluids in just a single phase , heat exchangers can be used either to heat a liquid to evaporate (or boil) it or used as condensers to cool a vapor and condense it to a liquid.此外，加热或冷却液只是一个阶段 ，换热器可用于加热液体蒸发（或煮沸） ，或用作冷凝器冷却蒸汽和凝结为液体。 In chemical plants and refineries , reboilers used to heat incoming feed for distillation towers are often heat exchangers. 3 4 在化工厂和炼油厂 ， reboilers用于热传入饲料蒸馏塔往往热交换器。 Distillation set-ups typically use condensers to condense distillate vapors back into liquid.蒸馏调校通常使用蒸馏冷凝器凝结成液态气体回。 Power plants which have steam -driven turbines commonly use heat exchangers to boil water into steam . 电厂有蒸汽驱动涡轮机普遍使用热交换器烧开水变成蒸汽 。 Heat exchangers or similar units for producing steam from water are often called boilers or steam generators.换热器或类似的单位生产的蒸汽水往往被称为锅炉或蒸汽发生器。 In the nuclear power plants called pressurized water reactors , special large heat exchangers which pass heat from the primary (reactor plant) system to the secondary (steam plant) system, producing steam from water in the process, are called steam generators .在核电厂的要求压水式反应堆 ，特别是大型换热器通过热从小学（反应堆厂房）系统二级（蒸汽厂）系统，生产的水蒸汽的过程中，被称为蒸汽发生器 。 All fossil-fueled and nuclear power plants using steam-driven turbines have surface condensers to convert the exhaust steam from the turbines into condensate (water) for re-use. 5 6 所有矿物燃料和核电厂使用蒸汽驱动涡轮机的表面冷凝器转换排汽从涡轮机到凝（水）的再利用。 In order to conserve energy and cooling capacity in chemical and other plants, regenerative heat exchangers can be used to transfer heat from one stream that needs to be cooled to another stream that needs to be heated, such as distillate cooling and reboiler feed pre-heating.为了节约能源和冷却能力，化学和其他植物，蓄热式换热器可用于传热从一个流，需要冷却到另一个流，需要加热，如沸蒸馏冷却和饲料预热。 This term can also refer to heat exchangers that contain a material within their structure that has a change of phase.这个词也可以指热交换器包含物质在其结构，有一个变化的阶段。 This is usually a solid to liquid phase due to the small volume difference between these states.这通常是固液相由于体积小，这些国家之间的区别。 This change of phase effectively acts as a buffer because it occurs at a constant temperature but still allows for the heat exchanger to accept additional heat.这种变化的阶段有效地作为一个缓冲区，因为它发生在一个恒定的温度，但仍允许换热接受额外的热量。 One example where this has been investigated is for use in high power aircraft electronics.一个例子在这个已被调查的是用于高功率电子设备的飞机。 edit Dynamic scraped surface heat exchanger动态刮掉表面换热器Another type of heat exchanger is called dynamic heat exchanger or scraped-surface heat exchanger .另一种类型的换热器被称为“ 动态换热器 ”或“ 刮面式换热器 ” 。 This is mainly used for heating or cooling with high- viscosity products, crystallization processes, evaporation and high- fouling applications.这主要是用于加热或冷却的高粘度产品， 结晶过程， 蒸发和高污染的应用。 Long running times are achieved due to the continuous scraping of the surface, thus avoiding fouling and achieving a sustainable heat transfer rate during the process.长时间运行的时间达到由于连续刮表面，从而避免污染和实现可持续的传热率的过程中。 The formula used for this will be Q=A*U*LMTD, whereby Q= heat transfer rate.该公式用于这将是为Q = A *的 *对数平均温差，从而为Q =热量传输速率。 edit Fluid heat exchangers流体换热器This is a heat exchanger with a gas passing upwards through a shower of fluid (often water), and the fluid is then taken elsewhere before being cooled.这是一个换热器气体通过向上通过淋浴流体（通常是水） ，以及流体然后才考虑其他冷却。 This is commonly used for cooling gases whilst also removing certain impurities, thus solving two problems at once.这是常用的冷却气体，同时删除一些杂质，从而解决两个问题一次。 It is widely used in espresso machines as an energy-saving method of cooling super-heated water to be used in the extraction of espresso.它广泛应用于咖啡机作为一项节约能源的方法，冷却过热的水，用于提取咖啡。 edit Plate Fin heat exchanger板翅式换热器This type heat exchanger uses sandwiched passages containing fins to increase the effectivity of the unit.这种类型换热器采用“夹心”的段落含有鱼翅，提高有效性的单位。 The designs include crossflow and counterflow coupled with various fin configurations such as straight fins, offset fins and wavy fins.该设计包括横向和逆流加上各种鱼翅配置如直鳍，鳍和抵消波浪鳍。 edit Adiabatic wheel heat exchanger绝热轮换热器A fourth type of heat exchanger uses an intermediate fluid or solid store to hold heat, which is then moved to the other side of the heat exchanger to be released.第四种类型的换热器使用的中间流体或固体储存举行热，然后转移到另一侧的换热得到释放。 Two examples of this are adiabatic wheels , which consist of a large wheel with fine threads rotating through the hot and cold fluids, and fluid heat exchangers.两个这方面的例子有绝热车轮 ，其中包括一个大型车轮旋转与罚款线程通过冷热流体和流体换热器。 This type is used when it is acceptable for a small amount of mixing to occur between the two streams.这种类型时使用，它是可以接受的少量混合发生两者之间的流。 edit Regenerative heat exchanger蓄热式热交换器A third type of heat exchanger is the regenerative heat exchanger .第三种类型的换热器是蓄热式热交换器 。 In this, the heat (heat medium) from a process is used to warm the fluids to be used in the process, and the same type of fluid is used either side of the heat exchanger (these heat exchangers can be either plate-and-frame or shell-and-tube construction).在这方面，热（热媒）由一个进程是用来温暖的液体，用于在这个过程中，与同一类型的液体是用来两边的换热器（这些热交换器可以是板块和帧或管壳式建筑） 。 These exchangers are used only for gases and not for liquids.这些换热仅用于气体，而不是液体。 The major factor for this is the heat capacity of the heat transfer matrix.的主要因素，这是热容量热转移矩阵。 edit Shell and tube heat exchanger edit