斯特林发动机 - 图文

斯特林发动机

斯特林发动机是一种闭循环活塞式热机,闭循环的意思是工作燃气一直保存在气缸内,而开循环则如内燃机和一些蒸气机需要与大气交换气体。斯特林发动机一般被归为外燃机。

切图以外的菱形驱动器测试配置斯特林发动机的设计：

* 粉红-热筒壁

* 深灰色-冷筒壁（与冷却进排气管在黄色） * 暗绿色-热绝缘分开的两个汽缸结束 * 浅绿色-置换活塞 * 深蓝色-功率活塞

* 淡蓝色-曲柄连杆和飞轮

没有表明：热源和热汇。 在此设计了置换活塞构造没有专门建造的再生 。

介绍

斯特林发动机在热机中的效率目前是最高的，有时可以达到80%。

In the conversion of heat into mechanical work, the Stirling engine has the potential to achieve the highest efficiency of any heat engine. It can theoretically perform up to the full Carnot efficiency, although not yet in practice. The practical limitations include the non-ideal properties of the working gas, and material properties such as friction, thermal conductivity, tensile strength, creep, rupture strength, and melting point. The Stirling engine can run on any heat source, including chemical, solar, geothermal and nuclear. There are many possible implementations of the Stirling engine. Most fall into the category of reciprocating piston engine.

In contrast to internal combustion engines, Stirling engines have the potential to use renewable heat sources more easily, to be quieter, and to be more reliable with lower maintenance. They are preferred for applications that value these unique advantages, particularly if the the cost per unit energy generated ($/kWh) is more important than the capital cost per unit power ($/kW). On this basis, Stirling engines are cost competitive up to about 100 kW.[3]

Compared to an internal combustion engine of the same power rating, Stirling engines currently have a higher capital cost and are usually larger and heavier. Their lower maintenance requirements make the overall energy cost comparable. The thermal efficiency is also comparable (for small engines), ranging from 15%-30%.[3]For applications such as micro-CHP, a Stirling engine is often preferable to an internal combustion engine. Other applications include water pumping, space-based astronautics, and electrical generation from plentiful energy sources that are incompatible with the internal combustion engine, such as solar energy, and biomass such as agricultural waste and other waste such as domestic refuse. Stirlings have also been used as a marine engine in Swedish Gotland class submarines. [4]

However Stirlings are generally not price-competitive as an automobile engine, due to high cost per unit power, low power density and high material costs.

In recent years, the advantages of Stirling engines have become increasingly significant, given the rise in liquid fuel prices and concerns such as peak oil and climate change. Stirling engines address these issues by being very compatible with all renewable energy and fuel sources. These growing interests in Stirling technology have fostered the ongoing research and development of Stirling devices, and R&D breakthroughs have in turn increased interest in the technology.

If supplied with mechanical power, Stirlings can function in reverse as a heat pump for heating or cooling. Experiments have been performed using wind power driving a Stirling cycle heat pump for domestic heating and air conditioning. In the late 1930s, the Philips Corporation of the Netherlands successfully utilized the Stirling cycle in cryogenic applications.[5]

Basic analysis is based on the closed-form Schmidt analysis {google翻译:}

斯特林发动机是一个封闭的循环蓄热式发动机，气体工质。 “封闭循环”是指工作流体内永久的发动机。工作流体是气体推动活塞上。这种外部热发动机可以驱动任何热源。 “再生”是指利用一个内部换热器称为'再生'这增加了发动机的热效率相比，类似的，但简单的热空气引擎。

斯特林循环的值得注意的是，其完善的理论效率;然而这还没有实现的理想仍然是一项巨大的工程挑战。然而，目前的设计，指出其效率高，操作安静和方便，他们可以利用什么否则将废热。斯特林发动机在目前激动人心的利益为核心的组成部分，国内热电联产（热电联产）单位，这可能产生重大影响全世界的能源消耗。 [ 1 ] [ 2 ]

空军是一个许多可能的气体，可用于在一个斯特林发动机。所谓“热空气引擎”一般用来包含任何热空气引擎的工作液。热空气引擎可以使用任何一个几个不同的热力循环，包括布雷顿循环，爱立信斯特林循环或周期。

在斯特林发动机已用于小型低功耗应用了近两个世纪。斯特林发动机继续使用他们的能力提供机械或电力，加热或冷却的应用，热源和散热片可用。

斯特林发动机背景

Name

Though it had been suggested as early as 1884 that all closed cycle air engines should be generically called Stirling engines after the inventor of the first practical example, the idea found little favour and the various types on the market continued to be known by the name of their individual designer or manufacturer. Then, in the 1940s, the Philips company was searching for a suitable name for its version of the 'air' engine which by that time had already been tested with other gases. Rejecting many suggestions, including 'hot gas engine' ('gas engine' was already in general use for internal combustion engines running on gaseous fuels) and 'external combustion engine' (did not differentiate between open and closed cycles), Philips eventually settled on 'Stirling engine' in April 1945. General acceptance of the term followed a few years later.[8]

Early years

Illustration to Robert Stirling's 1816 patent application of the air engine design which later came to be known as the Stirling Engine.

The Stirling engine (or Stirling's air engine as it is was known at the time) was invented and patented by Reverend Dr. Robert Stirling in 1816.[9] It followed earlier attempts at making an air engine but was probably the first to be put to practical use when in 1818 an engine built by Stirling was employed pumping water in a quarry.[10] The main subject of Stirling's original patent was a heat exchanger which he called an \

in a variety of applications. The patent also described in detail the employment of one form of the economiser in his unique closed-cycle air engine design[11] in which application it is now generally known as a 'regenerator'. Subsequent development by Robert Stirling and his brother James, an engineer, resulted in patents for various improved configurations of the original engine. Their pressurisation enhancement had by 1843 sufficiently increased power output enough to drive all the machinery at a Dundee iron foundry.[12]

As well as saving fuel, the inventors were motivated to create a safer alternative to the steam engines of the time,[13] whose boilers frequently exploded causing many injuries and fatalities.[14][15] The need for Stirling engines to run at very high temperatures to maximize power and efficiency exposed limitations in the materials of the day and the few engines that were built in those early years suffered unacceptably frequent failures (albeit with far less disastrous consequences than a boiler explosion[16]) - for example, the Dundee foundry engine was replaced by a steam engine after three hot cylinder failures in four years.[17]

Later nineteenth century developments

Subsequent to the failure of the Dundee foundry engine there is no record of the Stirling brothers having any further involvement with air engine development and the Stirling engine never again competed with steam as an industrial scale power source (steam boilers were becoming safer[18] and steam engines more efficient, thus presenting less of a target to rival prime movers). However, from about 1860 smaller engines of the Stirling/hot air type were produced in substantial numbers finding applications wherever a reliable source of low to medium power was required, such as raising water or providing air for church organs.[19] These generally operated at lower temperatures so as not to tax available materials, so were relatively inefficient. But their selling point was that, unlike a steam engine, they could be operated safely by anybody capable of managing a fire.[20] Several types remained in production beyond the end of the century, but apart from a few minor mechanical improvements the design of the Stirling engine in general stagnated during this period.[21]

Twentieth century revival

Philips MP1002CA Stirling generator of 1951

During the early part of the twentieth century the role of the Stirling engine as a \motor\was gradually usurped by the electric motor and small internal combustion engines until by the late 1930s it was largely forgotten, only produced for toys and a few small ventilating fans.[23] At this time Philips was seeking to expand sales of its radios into areas where electricity was unavailable and the supply of batteries uncertain. Philips’ management decided that a low-power portable generator would facilitate such sales and tasked a group of engineers at the company's research lab (the Nat. Lab) in Eindhoven to evaluate alternatives.

After a systematic comparison of various prime movers the Stirling engine's quiet (both audibly and in terms of radio interference) operation and ability to run on a variety of heat sources (common lamp oil - \and available everywhere\- was favoured), the team picked

Stirling.[24] They were also aware that, unlike steam and internal combustion engines, virtually no serious development work had been carried out on the Stirling engine for many years and asserted that modern materials and know-how should enable great improvements.[25]

Encouraged by their first experimental engine, which produced 16 watts of shaft power from a bore and stroke of 30x25mm,[26] Phillips began a development program. This work continued throughout World War II and by the late 1940s handed over the Type 10 to Philips’ subsidiary Johan de Witt in Dordrecht to be ‘productionised’ and incorporated into a generator set. The result, rated at 200 watts from a bore and stroke of 55x27 mm, was designated MP1002CA (known as the 'Bungalow set'). Production of an initial batch of 250 began in 1951, but it became clear that they could not be made at a competitive price and the advent of transistor radios with their much lower power requirements meant that the original rationale for the set was disappearing. Approximately 150 of these sets were eventually produced.[27] Some found their way into university and college engineering departments around the world[28] giving generations of students a valuable introduction to the Stirling engine.

Philips went on to develop experimental Stirling engines for a wide variety of applications and continued to work in the field until the late 1970s, but only achieved commercial success with the 'reversed Stirling engine' cryocooler. They did however take out a large number of patents and amass a wealth of information which they licensed to other companies and which formed the basis of much of the development work in the modern era.[29]

在将热变成机械功的转换上，史特林引擎在真实的热机中可达最高的热效率，至多80%，仅受工作气体和引擎材料的不理想性质限制，例如摩擦、热传导性、抗张强度、缓慢、熔点等。 此引擎理论上可用任何足量的热源运行，包括太阳能、化学能和核能。

与内燃机相比，史特林引擎往往维修需求较低，更高效、更安静、而且更可靠。它们倾向被应用于某些特殊用途以发扬其独特优点。 特别是首要目标非减低每单位功率的投资成本(金钱/千瓦)，而是减低引擎产生每单位能量的成本(金钱/度)的时候。

在额定功率下，史特林引擎的投资成本目前比内燃机引擎高，而且通常更大更重，因此这引擎科技很少单独以此作为竞争基准。 然而在一些用途上,适当的本益分析可令史特林引擎优于内燃机引擎。

近年来，鉴于能源成本普遍上涨，能源短缺和气候变迁之类的环境问题，史特林引擎的优点愈来愈显著。 对史特林引擎科技提高兴趣促进了史特林装置的研发。其应用涵盖借由不相容于内燃机的丰富能源抽水、宇基太空航行、发电，像是太阳能、农业废料还有家庭垃圾。

另一个史特林引擎的潜力是，若供应机械功，它可以作为一种热泵。已有实验利用风能驱动史特林热泵作为家用冷暖空调。

斯特林发动机功能描述

Engine operation

Since the Stirling engine is a closed cycle, it contains a fixed mass of gas called the \

fluid\gas enters or leaves the engine. No valves are required, unlike other types of piston engines. The Stirling engine, like most heat-engines, cycles through four main processes: cooling, compression, heating and expansion. This is accomplished by moving the gas back and forth between hot and cold heat exchangers, often with a regenerator between the heater and cooler. The hot heat exchanger is in thermal contact with an external heat source, such as a fuel burner, and the cold heat exchanger being in thermal contact with an external heat sink, such as air fins. A change in gas temperature will cause a corresponding change in gas pressure, while the motion of the piston causes the gas to be alternately expanded and compressed.

The gas follows the behavior described by the gas laws which describe how a gas's pressure, temperature and volume are related. When the gas is heated, because it is in a sealed chamber, the pressure rises and this then acts on the power piston to produce a power stroke. When the gas is cooled the pressure drops and this means that less work needs to be done by the piston to compress the gas on the return stroke, thus yielding a net power output.

When one side of the piston is open to the atmosphere, the operation is slightly different. As the sealed volume of working gas comes in contact with the hot side, it expands, doing work on both the piston and on the atmosphere. When the working gas contacts the cold side, its pressure drops below atmospheric pressure and the atmosphere pushes on the piston and does work on the gas.

To summarize, the Stirling engine uses the temperature difference between its hot end and cold end to establish a cycle of a fixed mass of gas, heated and expanded, and cooled and compressed, thus converting thermal energy into mechanical energy. The greater the temperature difference between the hot and cold sources, the greater the thermal efficiency. The maximum theoretical efficiency is equivalent to the Carnot cycle, however the efficiency of real engines is only a fraction of this value, even in highly optimized engines.

Sterling engine small clear.ogg

Play video

Video showing the compressor and displacer of a very small Stirling Engine in action

Very low-power engines have been built which will run on a temperature difference of as little as 7 °C, for example between the palm of a hand and the surrounding air, or between room temperature and melting water ice.[30][31][32]

[edit] Pressurization

In most high power Stirling engines, both the minimum pressure and mean pressure of the working fluid are above atmospheric pressure. This initial engine pressurization can be realized by a pump, or by filling the engine from a compressed gas tank, or even just by sealing the engine

when the mean temperature is lower than the mean operating temperature. All of these methods increase the mass of working fluid in the thermodynamic cycle. All of the heat exchangers must be sized appropriately to supply the necessary heat transfer rates. If the heat exchangers are well designed and can supply the heat flux needed for convective heat transfer, then the engine will produce power in proportion to the mean pressure, as predicted by the West number, and Beale number.[33][34] In practice, the maximum pressure is also limited to the safe pressure of the pressure vessel. Like most aspects of Stirling engine design, optimization is multivariate, and often has conflicting requirements. [35]

[edit] Lubricants and friction

A Stirling engine and generator set with 55 kW electrical output, for combined heat and power applications.

At high temperatures and pressures, the oxygen in air-pressurized crankcases, or in the working gas of hot air engines, can combine with the engine's lubricating oil and explode. At least one person has died in such an explosion.[36]

Lubricants can also clog heat exchangers, especially the regenerator. For these reasons, designers prefer non-lubricated, low-coefficient of friction materials (such as Rulon (plastic) or graphite), with low normal-forces on the moving parts, especially for sliding seals. Some designs avoid sliding surfaces altogether by using diaphragms for sealed pistons. These are some of the factors that allow Stirling engines to have lower maintenance requirements and longer life than internal-combustion engines.

发动机运行

由于斯特林发动机是一个封闭的循环，它包含一个固定的大规模的天然气被称为“工作流” ，最常见的空气，氢气或氦气。在正常运作，引擎是密封的，没有气体进入或离开发动机。无阀是必要的，不像其他类型的活塞式发动机。在斯特林发动机，最喜欢热引擎，通过4个周期的主要过程：冷却，压缩，加热和扩张。这是通过移动的气体之间来回热冷热交换器，往往与再生之间的加热器和冷却器。热换热器的热与外部的热源，如燃料燃烧器，和冷战式换热器是在接触热与外部散热片，如空气鱼翅。改变气体温度会引起相应的变化，气体压力，而运动的活塞造成的天然气将轮流扩大和压缩。

气体的行为如下描述了天然气的法律，说明气体的压力，温度和体积是有关系的。当气体被加热，因为它是在一个密封的房间，压力上升，这对当时行为的权力活塞产生动力中风。当冷却气体的压力下降，这意味着较少的工作需要做的活塞压缩气体返回中风，从而产生了净功率输出。

当一方活塞开放的气氛中，操作稍有不同。由于密封货量工作气体接触的热点方面，它的扩大，是做人的工作的活塞和气氛。当工作气体接触冷战一方，其压力低于大气压力的气氛推的活塞和不工作的天然气。

总之，使用斯特林发动机的温度差异其热端和冷端建立一个周期的一个固定数量的天然气，加热和扩大，冷却和压缩，从而热能转换为机械能。更大的温度差异的热点和冷源，更大的热效率。最高理论效率相当于卡诺循环，但效率的真正的发动机是只有一小部分的价值，即使是在高度优化的引擎。

斯特林引擎小clear.ogg

视频显示压缩机和置换的一个非常小的斯特林发动机在行动

非常的低功率发动机已建成这将运行在温差只有7 ℃ ，例如棕榈油之间的手和周围空气之间，或室温和融化水冰。 [ 30 ] [ 31 ] [ 32 ]

加压

在大多数高功率斯特林发动机，无论是最低压力和平均压力的工作流体高于大气压力。这一初步增压发动机可实现泵，或填补了发动机的压缩天然气罐，甚至只是发动机密封时的平均温度低于平均温度。所有这些方法提高质量的工作液中的热力循环。所有的换热器的尺寸必须适当提供必要的传热率。如果换热器是精心设计，可供应热通量所需的对流换热，然后将发动机产生电力中所占的比例平均压力，因为预测的一些西方国家和一些比尔。 [ 33 ] [ 34 ]在实际上，最大的压力也是有限的安全压力，压力容器。如同大多数方面的斯特林发动机的设计，优化多元，而且往往有矛盾的要求。 [ 35 ]

润滑油和摩擦

斯特林发动机和发电机组55千瓦的电力输出，为热电联产的应用。

在高温度和压力，氧气在空气加压曲轴箱，或在工作气体的热空气引擎，可以结合发动机的润滑油和爆炸。至少有一人已死于这种爆炸。 [ 36 ]

润滑油也可以堵塞换热器，特别是再生。由于这些原因，设计者宁愿不润滑，低摩擦系数材料（如卢伦（塑料）或石墨），低正常部队的运动部件，尤其是滑动密封。一些设计，避免滑动表面完全采用隔膜密封活塞。这些都是一些因素，使斯特林引擎有较低的维修要求和更长的寿命比内燃机

斯特林循环

Main article: Stirling cycle

The idealized or \book\Stirling cycle is a thermodynamic cycle with two isochores (constant volume) and two isotherms (constant temperature). It is the most efficient thermodynamic cycle capable of practical implementation in an engine - its theoretical efficiency equaling that of the hypothetical Carnot cycle. However real-world issues reduce the efficiency of actual engines, due to limits of convective heat transfer, and viscous flow (friction). There are also practical mechanical considerations, for instance a simple kinematic linkage may be favored over a more complex mechanism needed to replicate the idealized cycle.

主要文章：斯特林循环

在理想化或“文字书”斯特林循环是一个热力循环有两个isochores （恒容）和两个等温线（恒定的温度）。这是最有效的热力循环能够切实执行的引擎-其理论效率相当于这一虚构的卡诺循环。然而现实世界的问题，降低效率，实际的发动机，由于界限的对流换热和粘

性流动（摩擦） 。也有实际的机械因素，比如一个简单的运动联系起来可能是有一个更复杂的机制需要复制的理想化的周期

斯特林改进

Main article: Regenerative heat exchanger

In a Stirling engine, the regenerator is an internal heat exchanger and temporary heat store placed between the hot and cold spaces such that the working fluid passes through it first in one direction then the other. Its function is to retain within the system that heat which would otherwise be exchanged with the environment at temperatures intermediate to the maximum and minimum cycle temperatures,[37] thus enabling the thermal efficiency of the cycle to approach the limiting Carnot efficiency defined by those maxima and minima.

The primary effect of regeneration in a Stirling engine is to greatly increase the thermal efficiency by 'recycling' internally heat which would otherwise pass through the engine irreversibly. As a secondary effect, increased thermal efficiency promises a higher power output from a given set of hot and cold end heat exchangers (since it is these which usually limit the engine's heat throughput), though, in practice this additional power may not be fully realized as the additional \tends to have the opposite effect.

The easiest way to understand the regenerator, is to see it as a lump of matter placed in the flow path of the working gas that the working gas heats and cools as it flows from one side of the stirling engine to the other. As the gas leaves the hot side of the engine, the next goal of the designer is to cool the gas. If the regenerator mass is cool at that point, the hot gas will be cooled slightly by the regenerator as it passes it and then further cooled when the gas gets to the heat sink heat exchanger. The working fluid has then been cooled by two methods, the regenerator and the cold sink heat exchanger. This process has left the regenerator warm, that is some heat has been retained within the engine and not lost to the cold heat sink. The fluid must then leave the cold side of the engine and the designer's goal is to heat the fluid as much as possible. The gas passes through the warm regenerator, which heats the gas a little, and then the gas goes on to the hot side of the engine where it heats up further. As the cold gas moved past the regenerator it cooled the regenerator a little leaving it cooler and ready for the next cycle.

The regenerator is therefore a mass that is heated and cooled between the heat source and heat sink temperatures as the working fluid moves back and forth. The regenerator, as a working fluid pre-heater, pre-cooler, improves the ability to heat and cool the working fluid. This reduces the burden on the heat source and sink heat exchangers in moving the working fluid to the maximum high and low temperatures. The regenerator should not limit the flow of the working fluid as it moves about the engine, and it should not add additional volume of working fluid, just for the sake of adding a regenerator.

Designing a successful regenerator is a balance between high heat transfer with low viscous pumping losses and low dead space. These inherent design conflicts are one of many factors which limit the efficiency of practical Stirling engines. A typical design is a stack of fine metal

塞和其他松散装有柱塞泵。

1. Power piston (dark grey) has compressed the gas, the displacer piston (light grey) has moved so that most of the gas is adjacent to the hot heat exchanger.

1 。电力活塞（深灰色）已压缩天然气的置换活塞（浅灰色）已使大部分的气体是毗邻热换热器

2. The heated gas increases in pressure and pushes the power piston to the farthest limit of the power stroke.

2 。加热气体增加的压力和动力推动活塞的最远的限制并电力中风

3. The displacer piston now moves, shunting the gas to the cold end of the cylinder. 3 。活塞的置换现在动作，调气，以冷战结束缸。

4. The cooled gas is now compressed by the flywheel momentum. This takes less energy, since when it is cooled its pressure dropped.

4 。天然气的冷却现在压缩飞轮势头。这需要更少的能源，因为它是在冷却的压力下降

An Animation of the complete beta type Stirling cycle动画完整的测试版型斯特林循环

Gamma Stirling

* A gamma Stirling is simply a beta Stirling in which the power piston is mounted in a separate cylinder alongside the displacer piston cylinder, but is still connected to the same flywheel. The gas in the two cylinders can flow freely between them and remains a single body. This configuration produces a lower compression ratio but is mechanically simpler and often used in multi-cylinder Stirling engines. 伽玛刀斯特林

*一个伽玛斯特林只是一个测试斯特林，其中电力是柱塞安装在一个单独的缸旁边置换活塞缸，但仍然是连接到同一个飞轮。天然气在两个汽缸可以自由流动和它们之间仍然是一个单一的机构。这种配置产生一个较低的压缩比，但机械简单，常用于多缸斯特林发动机。 Other types

Other Stirling configurations continue to interest engineers and inventors. The rotary Stirling engine; seeks to convert power from the Stirling cycle directly into torque, similar to the rotary combustion engine. No practical engine has yet been built but a number of concepts, models and patents have been produced, such as the Quasiturbine engine.

An alternative to the mechanical Stirling device is the Fluidyne engine or heat pump, which use hydraulic piston(s) to implement the Stirling cycle. The work produced by a Fluidyne engine goes into pumping the liquid. In its simplest form, the engine contains a working gas, a liquid and two non-return valves.

其他类型

其他斯特林配置继续关心工程师和发明家。旋转斯特林发动机;寻求转换权力从斯特林循环直接进入扭矩，类似旋转的内燃机。没有实际引擎尚未建成，但一些概念，模型和专利已产生，如奎西引擎

另一种机械装置斯特林是Fluidyne引擎或热泵，使用液压活塞（星期日）实施斯特林循环。这项工作由一个Fluidyne进入引擎的液体泵。最简单的形式，引擎包含一个工作气体，液体和两个非单向阀。

Free-piston engines自由活塞发动机

\as pistons. In a \device, electrical energy may be added or removed by a linear alternator. This sidesteps the need for a linkage, and reduces the number of moving parts, friction and wear.

“自由活塞”斯特林发动机，包括那些液体活塞和那些作为活塞隔膜。在一个“自由活塞”装置，电力能源可能会增加或删除的线性发电机。这种回避需要有一个联系，并降低了一些运动部件，摩擦磨损。

In the early 1960s Professor W. T. Beale of Ohio University invented a free-piston version of the Stirling engine in order to overcome the difficulty of lubricating the crank mechanism. While the invention of the basic free-piston Stirling engine is generally attributed to Beale, independent inventions of similar types of engines were made by E. H. Cooke-Yarborough and C. West at the Harwell Laboratories of the UKAERE G. M. Benson also made important early contributions and

patented many novel free-piston configurations

在20世纪60年代初野生比尔教授的俄亥俄州立大学发明了一种自由活塞版本的斯特林发动机，以便克服困难，润滑曲柄机制。 虽然发明的基本自由活塞斯特林发动机一般归因于比尔，独立发明的类似类型的引擎作了高血压库克-亚伯勒和C在西哈韦尔实验室的UKAERE通用森也作出了重要贡献，并早日获得专利的许多新颖的自由活塞配置

What appears to be the first mention of a Stirling cycle machine using freely moving components is a British patent disclosure in 1876.[52] This machine was envisaged as a refrigerator (i.e., the reversed Stirling cycle). The first consumer product to utilize a free-piston Stirling device was a portable refrigerator manufactured by Twinbird Corporation of Japan and offered in the US by Coleman in 2004.

这似乎是第一次提到斯特林循环机使用自由运动部件是英国的专利在1876年披露的。 这台机器被设想为一台冰箱（即扭转斯特林循环）。第一次消费类产品，利用一个自由活塞斯特林装置是一种便携式冰箱制造的Twinbird公司提供的日本和在美国的科尔曼在2004年。

Thermoacoustic cycle热循环

Thermoacoustic devices are very different from Stirling devices, although the individual path traveled by each working gas molecule does follow a real Stirling cycle. These devices include the thermoacoustic engine and thermoacoustic refrigerator. High-amplitude acoustic standing waves cause compression and expansion analogous to a Stirling power piston, while out-of-phase acoustic traveling waves cause displacement along a temperature gradient, analogous to a Stirling displacer piston. Thus a thermoacoustic device typically does not have a displacer, as found in a beta or gamma Stirling.

热设备有很大的不同由Stirling装置，虽然个别路径搭乘每个工作气体分子不按照一个真正的斯特林循环。这些设备包括热声发动机和热声制冷机。高振幅声驻波造成压缩和扩大类似的斯特林功率活塞，而失去声相行波造成流离失所沿着温度梯度，类似于斯特林置换活塞。因此，热装置通常不会有一个置换，因为发现了一个测试或伽玛斯特林

热源

Virtually any temperature difference will power a Stirling engine. In the case where a small temperature differential is used to generate a significant amount of power, large flows of heating and cooling fluids must be pumped through the heat exchangers, causing parasitic losses that reduce efficiency. 几乎所有的温差将电力斯特林发动机。在的情况下，一个小的温度差别是用来产生大量的电力，大量的加热和冷却液泵浦必须通过热交换器，造成寄生虫的损失，降低效率。

The heat source may be derived from fuel combustion, hence the term \engine\although the heat source may also be solar, geothermal, waste heat, nuclear or even biological. 热源可来自燃料的燃烧，因此，长期“外部内燃机” ，但热源也可能是太阳能，地热，废热，核或什至生物武器。

A source may also be below the ambient temperature. Such “cold sinks” as cryogenic fluid or ice water may drive Stirlings, albeit in reverse. 一位消息人士也可低于环境温度。这种“冷汇”作为低温液体或冰水可以驾驶Stirlings ，尽管扭转。

Since the combustion products do not contact the internal moving parts of the engine, a Stirling engine can run on fuels that would otherwise damage the engine’s internals, such landfill gas or siloxane. 由于燃烧产物不接触的内部运动部件的发动机，斯特林发动机可以运行在燃料，否则破坏了发动机的内部，例如填埋气体或硅油

The U.S. Department of Energy in Washington, NASA Glenn Research Center in Cleveland, and Infinia Corporation of Kennewick, Wash., are developing a free-piston Stirling converter for a Stirling Radioisotope Generator using a plutonium heat source. 美国能源部在华盛顿，美国NASA格林研究中心在克利夫兰，并Infinia公司肯纳威克，华盛顿正在开发一种自由活塞斯特林转换斯特林发电机使用放射性同位素钚热源

Point focus parabolic dish with Stirling engine and its solar tracker at Plataforma Solar de Almería (PSA) in Spain.点集中抛碟与斯特林发动机和太阳能跟踪平台上的太阳能阿尔梅里亚（变压吸附）在西班牙

斯特林发动机优势

* They can run directly on any available heat source, not just one produced by combustion, so they can run on heat from solar, geothermal, biological, nuclear sources or waste heat from industrial processes.

* A continuous combustion process can be used to supply heat, so most types of emissions can be reduced.

* Most types of Stirling engines have the bearing and seals on the cool side of the engine, and they require less lubricant and last longer than other reciprocating engine types.

* The engine mechanisms are in some ways simpler than other reciprocating engine types. No valves are needed, and the burner system can be relatively simple.

* A Stirling engine uses a single-phase working fluid which maintains an internal pressure close to the design pressure, and thus for a properly designed system the risk of explosion is low. In comparison, a steam engine uses a two-phase gas/liquid working fluid, so a faulty relief valve can cause an explosion.

* In some cases, low operating pressure allows the use of lightweight cylinders.

* They can be built to run quietly and without an air supply, for air-independent propulsion use in submarines.

* They start easily (albeit slowly, after warm-up) and run more efficiently in cold weather, in contrast to the internal combustion which starts quickly in warm weather, but not in cold weather.

* A Stirling engine used for pumping water can be configured so that the water cools the compression space. This is most effective when pumping cold water.

* They are extremely flexible. They can be used as CHP (combined heat and power) in the winter and as coolers in summers.

* Waste heat is relatively easily harvested (compared to waste heat from an internal combustion engine) making Stirling engines useful for dual-output heat and power systems.

*他们可以直接运行在任何现有的热源，不只是一个生产的燃烧，这样他们就可以运行热量从太阳能，地热，生物，核来源或废热从工业生产过程。

*连续燃烧过程可用于供热，使大多数类型的排放量可减少。

*大多数类型的斯特林发动机轴承和密封的冷却一侧的发动机，它们需要较少的润滑剂和持续更长的一段时间比其他类型往复式发动机。

*引擎机制在某些方面比其他简单的往复式发动机类型。无阀需要，以及燃烧系统可以相对简单。

*一个斯特林发动机采用了单相工质保持了密切的内部压力的设计压力，从而为系统设计适当的风险爆炸低。相较之下，蒸汽机采用了两相气/液工作液，所以溢流阀故障可能会导致爆炸。

*在某些情况下，运行压力低，可使用轻便的气瓶。

*他们可以建造安静地运行，没有送风，空气独立推进使用潜艇。

*他们开始轻松地（尽管进展缓慢，在热身）和运行更有效地在寒冷的天气相反，内部燃烧迅速开始在温暖的天气，但不是在寒冷的天气。

*一个斯特林发动机用于抽水可配置，使水冷却的压缩空间。这是最有效的抽水冷水。

*他们是极其灵活。它们被用来作为热电联产（热电联产）在冬季和夏季冷却器。

*废热是相对容易收获（相比废热内燃机）斯特林发动机决策有用的双输出热量和电力系统。

斯特林发动机弊端

Size and cost issues尺寸和成本问题

* Stirling engine designs require heat exchangers for heat input and for heat output, and these must contain the pressure of the working fluid, where the pressure is proportional to the engine power output. In addition, the expansion-side heat exchanger is often at very high temperature, so the materials must resist the corrosive effects of the heat source, and have low creep (deformation). Typically these material requirements substantially increase the cost of the engine. The materials and assembly costs for a high temperature heat exchanger typically accounts for 40% of the total engine cost

*斯特林发动机的设计要求换热器的热输入和热输出，这些都必须包含的压力的工作流体，那里的压力是成正比的发动机输出功率。此外，扩展方面的换热器往往是非常高的温度，所以材料必须抵制的腐蚀作用，热源，并已低蠕变（变形）。这些材料通常要求大幅度增加的成本引擎。这些材料和组装成本的高温换热器通常占40 ％的总成本引擎

* All thermodynamic cycles require large temperature differentials for efficient operation. In an external combustion engine, the heater temperature always equals or exceeds the expansion temperature. This means that the metallurgical requirements for the heater material are very demanding. This is similar to a Gas turbine, but is in contrast to a Otto engine or Diesel engine, where the expansion temperature can far exceed the metallurgical limit of the engine materials, because the input heat-source is not conducted through the engine, so engine materials operate closer to the average temperature of the working gas.

*所有热力循环需要较大的温度差别的高效率运作。在外部内燃机，加热器的温度始终等于或超过扩大的温度。这意味着，冶金所需的加热器材料的要求非常严格。这是类似的燃气轮机，但相反的奥托引擎或柴油发动机，那里的温度可以扩大远远超过了冶金界限的引擎材料，因为投入热源不是通过的引擎，所以引擎材料经营更接近的平均温度的工作气体。

* Dissipation of waste heat is especially complicated because the coolant temperature is kept as low as possible to maximize thermal efficiency. This increases the size of the radiators, which can make packaging difficult. Along with materials cost, this has been one of the factors limiting the adoption of Stirling engines as automotive prime movers. For other applications high power density is not required, such as Ship propulsion, and stationary microgeneration systems using combined heat and power (CHP).

*耗散的废热尤其是复杂的，因为冷却剂的温度保持尽可能低的水平，以最大限度地提高热效率。这增加了大小的散热器，它可以使包装困难。随着原料成本，这一直是一个因素限制了通过斯特林发动机作为汽车主要推动者。对于其他应用高功率密度并不需要，如船用推进器，和固定微型系统采用热电联产（热电联产） 。

Power and torque issues功率和扭矩的问题

Stirling engines, especially those that run on small temperature differentials, are quite large

for the amount of power that they produce (i.e. they have low ). This is primarily due to the heat transfer coefficient of gaseous convection which limits the that can be attained in a typical cold heat exchanger to about 500 W/(m·K), and in a hot heat exchanger to about 500-5000 W/(m·K). Compared to internal combustion engines, this makes it more challenging for the engine designer to transfer heat into and out of the working gas. Increasing the temperature differential and/or pressure allows Stirling engines to produce more power, assuming the heat exchangers are designed for the increased heat load, and can deliver the convected heat flux necessary.

斯特林发动机，尤其是那些上运行的小型温度差别，是相当大的金额的权力，他们生产（即低）。这主要是由于传热系数的气体对流从而限制了，可以实现在一个典型的冷战式换热器，以约500瓦/ （米K ）和热换热器约500-5000瓦/ （系数） 。 相比，内燃机，这使得它更具挑战性的引擎设计师转让热输入和输出的工作气体。提高温度差和/或压力使斯特林发动机生产更多的权力，承担换热器设计用于增加热负荷，并能提供convected热流必要的。

A Stirling engine cannot start instantly; it literally needs to %up\This is true of all external combustion engines, but the warm up time may be shorter for Stirlings than for others of this type such as . Stirling engines are best used as constant speed engines.

斯特林引擎无法启动瞬间，它实际上需要“热身” 。这是真正的所有外部内燃发动机，但热身的时间可能会缩短为Stirlings比其他这种类型，如。斯特林发动机是用来作为最好的恒速发动机

Power output of a Stirling tends to be constant and to adjust it can sometimes require careful design and additional mechanisms. Typically, changes in output are achieved by varying the displacement of the engine (often through use of a arrangement), or by changing the quantity of working fluid, or by altering the piston/displacer phase angle, or in some cases simply by altering the engine load. This property is less of a drawback in hybrid electric propulsion or %utility generation where constant power output is actually desirable.

输出功率为斯特林往往是不断调整它有时需要仔细设计的和额外的机制。通常情况下，改变输出所取得的位移不同的引擎（通常是通过使用一种安排），或改变的数量，工作液，或通过改变活塞/置换相角，或在某些情况下只需通过改变发动机负荷。此属性不是一个缺陷在混合动力电动推进或“基本负荷”实用一代在恒功率输出实际上是可取的

Gas choice issues气体的选择问题

The use of working fluids other than air was pioneered by Phillips following a fatal accident involving a lubricating oil explosion in a highly pressurized air engine:利用工作以外的其他液体空气开创后，菲利普斯事故涉及爆炸润滑油在一个高度加压空气引擎：

* Hydrogen's low viscosity and high thermal conductivity make it the most powerful working gas, primarily because the engine can run faster than with other gases. However, due to hydrogen bonding, and given the high diffusion rate associated with this low molecular weight gas, particularly at high temperatures, H2 will leak through the solid metal of the heater. Diffusion through carbon steel is too high to be practical, but may be acceptably low for metals such as aluminium, or even stainless steel. Certain ceramics also greatly reduce diffusion. Hermetic

pressure vessel seals are necessary to maintain pressure inside the engine without replacement of lost gas. For HTD engines, auxiliary systems may need to be added to maintain high pressure working fluid. These systems can be a gas storage bottle or a gas generator. Hydrogen can be generated by electrolysis of water, the action of steam on red hot carbon-based fuel, by gasification of hydrocarbon fuel, or by the reaction of acid on metal. Hydrogen can also cause the embrittlement of metals. Hydrogen is a flammable gas, which is a safety concern, although the quantity used is very small, and it is arguably safer than other commonly used flammable gases. *氢的低粘度和高导热性使它成为最强大的工作气体，主要是因为发动机可以运行速度比其他气体的排放。然而，由于氢键，并考虑到传播率高与此相关的低分子量气体，特别是在高温下，氢气泄漏将通过固态金属的加热器。通过扩散碳钢太高是切实可行的，但可能是可接受的低金属，如铝，甚至不锈钢。某些陶瓷也大大减少扩散。密封压力容器海豹是必要的，以保持压力的发动机内没有更换了天然气。为天地HTD引擎，辅助系统可能需要增加保持高压工作液。这些系统可以是一个天然气储存瓶或气体发生器。氢可以生成的电解水，蒸汽行动的红碳为基础的燃料，通过气化型碳氢燃料，或由反应的酸对金属。氢也可以导致脆的金属。氢气是一种易燃气体，这是一个安全问题，但使用的数量非常小，它可说是比其他安全常用的可燃气体。

* Most technically advanced Stirling engines, like those developed for United States government labs, use helium as the working gas, because it functions close to the efficiency and power density of hydrogen with fewer of the material containment issues. Helium is inert, which removes all risk of flammability, both real and perceived. Helium is relatively expensive, and must be supplied by bottled gas. One test showed hydrogen to be 5 percentage points absolutely (24% relatively) more efficient than helium in the GPU-3 Stirling engine.[55] The researcher Allan Organ demonstrated that a well designed air engine is theoretically just as efficient as a helium or hydrogen engine. However, helium or hydrogen engines are several times more powerful per unit volume.

*技术上最先进的斯特林发动机，像那些发达国家的美国政府实验室，使用氦作为工作气体，因为它的职能接近的效率和功率密度的氢较少的物质控制问题。氦气是惰性的，它删除所有危险的易燃，包括不动产和知觉。氦气是相对昂贵，而且必须提供的瓶装气体。一试验表明氢气是5个百分点绝对（ 24 ％相对）更有效率的氦的GPU - 3斯特林发动机。 [ 55 ]研究员艾伦机关证明，精心设计的空气发动机是从理论上公正高效作为一个氦或氢燃料发动机。然而，氦或氢发动机几次更强大的单位体积。

* Some engines use air or nitrogen as the working fluid. These gases have much lower power density (which increases engine costs) but they are more convenient to use, and they minimize the problems of gas containment and supply (which decreases costs). The use of Compressed air in contact with flammable materials or substances such as lubricating oil, introduces an explosion hazard, because compressed air contains a high partial pressure of oxygen. However, oxygen can be removed from air through an oxidation reaction, or bottled nitrogen can be used which is nearly inert and very safe.

*一些引擎使用空气或氮气作为工作液。这些气体都低得多的功率密度（从而增加发动机的费用），但他们更方便地使用，并尽量减少他们的问题，遏制和天然气供应量（降低成本）。使用压缩空气接触易燃材料或物质，如润滑油，介绍了爆炸危险，因为压缩空气中含有高氧分压。但是，氧气可以从空气通过一个氧化反应，或瓶装氮可用于几乎是惰性的，非

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