直燃式溴化锂吸收式制冷压缩机是一种燃气型溴化锂机组，它适应我国西部缺电而燃气较丰富的地区使用。由于燃气具有特殊性能，因此，它除具有一般制冷压缩机的保护装置外，还设置了如下特殊保护装置。
（1）安全点火装置
燃气型机组的点火装置由点火燃烧器、点火稳压器、点火电磁阀等组成，其点火燃烧器由火焰检测器控制。点火燃烧器投入工作后，火焰检测器对其产生的火焰进行检测，当确认正常后，延时点燃主燃烧系统，并在主燃烧器正常工作后，点火燃烧器自行熄灭。如点火失败，则点火检测器控制供油阀不开启，以防止燃油外溢而造成事故。
（2）燃料压力保护装置
燃气型机组的燃料压力保护装置是一种稳定燃料压力的装置，以防止在燃烧过程中燃料压力产生波动，压力过高而发生事故。同时又防止压力过低而出现熄火现象。
（3）熄火安全装置
燃气型机组的熄火安装装置是用来排出机组在熄火时在炉膛内残留的燃气，防止产生燃烧。
（4）空气压力开关
燃气型机组的空气压力开关，用来控制机组的正常运行压力，当空气压力低于490MPa时，压力开关控制机组便停止运行。
（5）排气高温控制
燃气型机组的排气温度由高温继电器控制，当排气温度超过300℃时，排气温度继电器动作，切断电源，使机组停止运行。
（6）燃烧器风扇过电流保护
当因某种原因而引起风扇工作电流过大时，保护器动作，切断电源，以保护风扇电动机不至于烧坏。
History of Refrigeration
For centuries,people have known that the evaporation of water produces a cooling effect. At first, they did not attempt to recognize and understand the phenomenon, but they knew that any portion of the body that became wet felt cold as it dried in the air. At least as early as the second century evaporation was used in Egypt to chill jars of water,and it was employed in ancient India to make ice(Neuberger,1930).（几个世纪以来,人们已经认识到水蒸发可以产生冷却效果｡起初,人们没有试图去认知和理解这种现象,但人们知道身体的任一潮湿部分在空气中晾晒时会有冷的感觉｡至少早在二世纪,蒸发在埃及被用来冷却坛装的水,在古印度被用来制冰(Neuberger,1930)｡）
The first attempts to produce refrigeration mechanically depended on the cooling effects of the evaporation of water. In 1755 William Cullen, a Scottish physician, obtained sufficiently low temperatures for ice making. He accomplished this by reducing the pressure on water in a closed container with an air pump. At a very low pressure the liquid evaporated or boiled at a low temperature. The heat required for a portion of water to change phase from liquid to vapor was taken from the rest of the water, and at least part of the water remaining turned to ice. Since Cullen, many engineers and scientists have created a number of inventions for clarifying the main principles of mechanical refrigeration (Goosman, 1924). In 1834, Jacob Perkins, an American residing in England, constructed and patented a vapor-compression machine with a compressor, a condenser, an evaporator, and a cock between the condenser and the evaporator (Critchell and Raymond, 1912). He made it by evaporating under reduced pressure a volatile fluid obtained by the destructive distillation of India rubber. It was used to produce a small quantity of ice, but not commercially. Growing demand over the 30 years after 1850 brought great inventive accomplishments and progress. New substances, e.g ammonia and carbon dioxide, which were more suitable than water and ether, were made available by Faraday, Thilorier, and others, and they demonstrated that these substances could be liquefied.（机械制冷的第一次尝试依赖于水蒸发产生的冷却效果｡1755年,苏格兰医师William Cullen得到了足够低的温度用于制冰｡他利用一个空气泵来降低一个封闭容器内水面上的压力来达到这个目的｡在相当低的压力下,液体可在低温下蒸发或沸腾｡一部分水从液态到汽态发生相变所需要的热量来自余下的水,至少剩余的部分水会变成冰｡从Cullen开始,许多工程师和科学家创造了大量的发明来阐释机械制冷的原理(Goosman,1924)｡1834年,定居英格兰的美国人Jacob Perkins造出了一台由压缩机､冷凝器､蒸发器和位于冷凝器和蒸发器之间的开关组成的蒸汽压缩式制冷机,并取得了专利(Critchell and Raymond,1912)｡他是通过在减压下蒸发一种易挥发的流体实现的,该流体是通过一种印度橡胶干馏得到的｡它被用于少量冰的生产,但未被商业化｡1850年后30多年的增长需要带来了巨大的创造性的成果和进展｡比水和乙醚更适合的新工质被Faraday,Thilorier等人发现,如氨和二氧化碳,他们证明了这些物质可被液化｡）
The theoretical background required for mechanical refrigeration was provided by Rumford and Davy, who had explained the nature of heat, and by Kelvin, Joule, and Rankine, who were continuing the work begun by Sadi Carnot informulating the science of thermodynamics(Travers,1946). Refrigerating machines appeared between 1850 and 1880, and these could be classified according to substance (refrigerant). Machines using air as a refrigerant were called compressed-air or cold-air machines and played a significant role in refrigeration history.Dr.John Gorrie, an American, developed a real commercial cold-air machine and patented it in England in 1950 and in America in 1951(DOI,1952).（Rumford､Davy､Kelvin､Joule和Rankine提供了机械制冷所需要的理论背景,Rumford和Davy解释了热的本质,Kelvin､Joule和Rankine延续了Sadi Carnot的工作,明确的对热力学进行了阐述(Travers,1946)｡制冷机出现在1850至1880年之间,并可以依据工质(制冷剂)分类｡用空气作为制冷剂的制冷机,称为压缩空气机或冷空气制冷机,并在制冷史上起着重要的作用｡美国人John Gorrie博士,开发了一种真正商用的冷空气制冷机,并于1950年在英格兰,1951年在美国获得专利(DOI,1952)｡）
Refrigerating machines using cold air as a refrigerant were divided into two types, closed cycle and open cycle.In the closed cycle,air confined to the machine at a pressure higher than the atmospheric pressure was utilized repeatedly during the operation. In the open cycle, air was drawn into the machine at atmospheric pressure and when cooled was discharged directly into the space to be refrigerated.In Europe.Dr.Alexander C.Kirk commercially developed a closed cycle refrigerating machine in 1862, and Franz Windhausen invented a closed cycle machine and patented it in America in 1870. The open cycle refrigerating machines theoretically outlined by Kelvin and Rankine in the early 1850s were invented by a Frenchman, Paul Giffard, in 1873 and by Joseph J.Colemanand James Bellin Britain in 1877(Roelker,1906).（用冷空气作制冷剂的制冷机可分为两类:闭合循环和开式循环｡在闭合循环中,进入制冷机的高于大气压的空气在工作中可被重复利用｡在开口循环中,空气在大气压下进入制冷机,被冷却后,直接排放到需要制冷的空间｡在欧洲,1862年Alexander C. Kirk博士开发了一种商业用闭合循环制冷机,Franz Windhausen发明了一种闭合循环制冷机并于1870年在美国获得专利｡在19世纪50年代早期,Kelvin和Rankine在理论上构件了开口循环制冷机的轮廓,法国人Paul Giffard于1873年,Joseph J. Coleman和James Bell在英国于1877年,发明了开口循环制冷机(Roelker,1906)｡）
In 1860, a French engineer, Ferdinand P. Edniond Carre, invented an intermittent crude ammonia absorption apparatus based on the chemical affinity of ammonia for water, which produced ice on a limited scale. Despite its limitations, it represented significant progress.（1860年,法国工程师Ferdin and P .Edniond Carre基于氨和水的化学新和力,发明了一种间歇式氨吸收制冷装置,用于小规模制冰｡尽管具有局限性,但体现了很大的进步｡）
His apparatus had a hand pump and could freeze a small amount of water in about 5 minutes(Goosman, 1924). It was widely used in Paris for a while, but it suffered from a serious disadvantage in that the sulfuric acid quickly became diluted with water and lost its affinity. （他的装置有一个手压泵,能够在大约5分钟内使少量的水结冰(Goosman,1924)｡它在巴黎广泛应用了一段时间,但它有一个严重的缺点,就是硫酸遇水会迅速变稀,失去其亲和力｡）
The real inventor of a small, hand-operated absorption machine was H.A. Fleuss, who designed an effective pump for this machine. A comparatively large-scale ice making absorption unit was constructed in 1878 by F. Windhausen. It operated continuously by drawing water from sulfuric acid with additional heat to increase the affinity(Goosman,1924).（小型手动吸收式制冷机的真正发明者是H.A.Fleuss,他为该制冷机设计了高效的泵｡F.Windhausen于1878年,制成了规模相当大的吸收式制冰机｡它通过加热硫酸的方式提高硫酸的浓度来连续工作(Goosman,1924)｡）
One of the earliest of the vapor-compression machines was invented and patented by an American professor, Alexander C. Twining,in 1853.He established an ice production plant using this system in Cleveland, Ohio and could produce close to a ton per day. After that, a number of other inventors experimented with vapor-compression machines which used ether or its compounds (Woolrich, 1947). In France F.P.E. Carre developed and installed an ether-compression machine, and Charles Tellier (who was a versatile pioneer of mechanical refrigeration) constructed a plant using methyl ether as a refrigerant. In Germany Carl Linde,financed by brewers, established a methyl ether unit in 1874.Just before this Linde had paved the way for great improvements in refrigerating machinery by demonstrating how its thermodynamic efficiency could be calculated and increased (Goosman, 1924). （最早的蒸气压缩式制冷机之一是由美国教授Alexander C. Twining于1853年发明的,并获得专利｡他利用该系统在Cleveland,Ohio建成了一个制冰厂,日产冰量接近1吨｡自那之后,大量的发明家用以醚及其化合物为工质的蒸汽压缩式制冷机进行试验(Woolrich,1947)｡在法国,F.P.E.Carre开发并安装了一台乙醚为工质的压缩式制冷机,Charles Tellier(多才多艺的机械制冷先驱者)用甲醚作为制冷剂构件了一台装置｡在德国Carl Linde,由酿酒者提供资金于1874年建成了一个甲醚制冷装置｡仅仅在此之前,Linde已通过证明如何计算和提高制冷机的热力学效率,为制冷机的巨大发展铺平了道路(Goosman,1924)｡）
Inventors of compression machines also experimented with ammonia, which became the most popular refrigerant and was used widely for many years.In the 1860s Tellier developed an ammonia-compression machine.In 1872 David Boyle made satisfactory equipment for ice making and patented it in 1872 in America.Nevertheless, the most important figure in the development of ammonia-compression machines was Linde, who obtained a patent in 1876 for one which was installed in Trieste brewery the following year. Later, Linde's model became very popular and was considered excellent in its mechanical details (Awberry, 1942). The use of ammonia in the compression refrigerating machines was a significant step forward. In addition to its thermodynamic advantage, the pressures it required were easy to produce, and machines which used it could be small in size. In the late 1860s, P.H. Van der Weyde of Philadelphia got a patent for a compression unit which featured a refrigerant composed of petroleum products (Goosman, 1924). In 1875 R.P. Pictet at the University of Genevaint roduced a compression machine that used sulfuric acid.In 1866 T.S.C.Lowe, an American, developed refrigerating equipment that used carbon dioxide. Carbon dioxide compression machines became important, because of the gas's harmlesness, in installations where safety was the primary concern,although they were not used extensively until the 1890s(Awberry,1942). Between 1880 and 1890 ammonia-compression installations became more common. By 1890 mechanical refrigeration had proved to be both practical and economical for the food refrigeration industry.Europeans provided most of the theoretical background for the development of mechanical refrigeration, but Americans participated vigorously in the wide spread inventive activity between 1850 and 1880.（压缩制冷机的发明者们,也曾用最流行的､并被广泛应用多年的制冷剂氨做过试验｡在19世纪60年代,Tellier开发了一台氨压缩制冷机｡在1872年,David Boyle制成了令人满意的制冷装置,并于1872年在美国申请专利｡然而,在氨压缩制冷机的发展过程中最重要的人物是Linde,他于1876年获得专利并在第二年安装在Trieste的酿酒厂｡后来,Linde的模型变的非常流行,从机械方面说它被认为是最完美的(Awberry,1942)｡氨在压缩式制冷机中的应用是重要的进步｡除了其热力学优点外,它所需要的压力容易达到,应用它的机器在体积上可以很小｡在19世纪60年代晚期,费城的P.H.Vander Weyde获得了一项压缩式制冷机的专利,该压缩机的特点是以由石油产品构成的混合物作为制冷剂(Goosman,1924)｡1875年,日内瓦大学的R.P.Pictet引进了一台使用硫酸的压缩式制冷机｡1866年,美国人T.S.C.Lowe开发了使用二氧化碳的制冷装置｡二氧化碳压缩式制冷机,尽管在19世纪90年代以前未得到广泛应用,但因该气体的无害性,它在安全是首要关心问题的安装中变得非常重要(Awberry,1942)｡在1880至1890年间,氨压缩机的安装变得更加普遍｡到1890年,在食品制冷行业机械制冷已被证实是既可行又经济的｡欧洲人为机械制冷的发展提供了大部分的理论背景,而美国人在1850到1880年间却把更多的精力投入到广泛的发明创造活动中｡）
Steady technical progress in the field of mechanical refrigeration marked the years after 1890.Revolutionary changes were not the rule,but many improvements were made,inseveral countries,in the design and construction of refrigerating units, as well as in their basic components,compressors,condensers,and evaporators.（在机械制冷领域,平稳的技术进步是在1890年后｡革命性的变化不是主要的,但在许多国家,制冷装置的设计与构造取得了很大的进步｡它们的基本部件､压缩机､冷凝器和蒸发器也取得了很大的进步｡）