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1、电喷柴油机发动机工作原理和系统技术介绍船用柴油机是怎样工作的？ 柴油机是一种内燃机，通过把燃油喷入高温高压的燃烧室而发火。船用柴油机是一种在船上使用的柴油机。其工作原理如下： 一定量的新鲜空气被吸入或泵入汽缸并被运动的活塞压缩至很高的压力。空气被压缩时，温度升高，便点燃喷入汽缸的油雾。燃油的燃烧增加了缸内空气的热量，使空气膨胀并迫使发动机活塞对曲轴做功，随之驱动螺旋桨。两次喷油期间的运转过程叫一个工作循环。它由一些程序固定的过程组成。这个循环可在两个行程或四个行程内完成。四冲程柴油机的工作循环需四个独立的活塞行程，即吸气，压缩，膨胀和排气。如果我们把吸气和排气行程与压缩和膨胀行程结合起来，四冲
2、程柴油机就变成了二冲程柴油机。二冲程循环从活塞离开其行程底部，即下止点（BDC）向上运行开始，气缸侧面的进气口即扫气口是打开的，排气口也是打开的。经压缩的新鲜空气充入气缸，通过排气口将上一行程的残气吹出。 当活塞上行至其行程的1/5时，关闭进，排气口，随后空气在活塞上行中被压缩。当活塞上行到行程底部，即上止点（TDC）时空气的压力和温度都上升到很高的数值。此时喷油器把很细的油雾喷入灼热的空气中，燃烧开始，在气体中产生更高的压力。 随着高压气体的膨胀，活塞被推动下行直到它打开排气口，燃烧过的气体开始排出，活塞继续下行直到它打开进气口，另一个循环开始。 在二冲程柴油机中，曲轴转一周产生一个动力行程
3、，即做功行程；而在四冲程柴油机中，曲轴转两周才产生一个动力行程。这就是为什么从理论上说二冲程柴油机能产生相同尺寸的四冲程柴油机的两倍功率。然而，扫气不充分和其他损失使这一优势降到大约1.8倍。 在船上，每种柴油机都有他的应用。低速（即90120 r/min）主推进柴油机以二冲程工作。在此低速时，机桨间不需减速箱。四冲程柴油机（通常以中速运转，转速在250750r/min）用于发电机，并且有时作推进主机，用减速箱提供90120 r/min的速度。 工作循环 柴油机可设计成以二冲程循环或四冲程循环工作，二者解释如下： 四冲程循环 典型的两转四冲程循环的过程。通常从上止点（TDC，发火）开始绘制，从
4、上止点 （TDC，扫气）开始解释。上止点又叫内止点。 沿该顺时针看，开始时进，排气阀都是打开的（所有现代四冲程柴油机均有气阀机构）。如果柴油机是自然换气或带有径流增压气的小型高速机，气阀的重叠时间，即两气阀同时开启的时间将很短。排气阀将在上止点后（ATDC）10左右关闭。 推进柴油机和绝大多数1000r/min以下运转的辅助发电柴油机几乎都采用涡轮增压，并设计成在这一时刻让大量的扫气空气贯穿流动以控制适当的叶片温度。在这种情况下，排气阀将保持开启直至上止点后5060关闭。随着活塞在其吸气行程向外或下止点下行，它将吸入大量新鲜空气。为使吸入空气量达到最大，并补偿因阀落座造成的开启量减少或吸气惯性
5、作用，进气阀保持开启，直到下止点后大约2530（145155BTDC）。这一过程称之为进气阀关闭。充入的空气然后被上行的活塞压缩至大约550C。依柴油机的型号和转速而定，大约在1020BTDC，喷油器喷入精细雾化的燃油。喷入的燃油在27内着火（也依机型而定），活塞在膨胀行程下行，在3050的期间内燃烧。活塞的运动通常有利于诱导空气助燃。 在大约120150ATDC，排气阀打开（EVO）。这样选择正时能迅速将缸内气体排至排气管。这样可以：（a）保留足够的能量驱动废气涡轮增压器；（b）减小缸内压力在下止点时达最小值以减小排气行程消耗的泵气功。上行的活塞驱赶残留的废气，在7080BTDC，进气阀打开
6、，这样向外流动的气体惯性加上正的压差（此时通常在汽缸中是存在的），就产生了空气对废气的贯穿气流以清扫汽缸。 如果柴油机是自然换气的，进气阀开启约在上止点前10。工作循环重新开始。 二冲程循环 典型二冲程循环的过程，正如其名称所指，工作循环是在曲轴转一周内完成的。 二冲程柴油机总是有进气口的，该气口被下行的活塞打开时使空气进入汽缸。废气可以经与邻近的排气口由同一活塞控制排出（回流扫气），或经气缸另一侧的排气口排出，或经排气阀排出（直流扫气）。 从上止点开始，燃烧已经进行。排气在上止点后110120开始，进气在随后2030，即上止点后130150开始迅速吹扫气缸。用这种方式，以音速流动的废气靠惯性
7、促使空气迅速流过气缸，以产生最小的（新废气）掺混，因为所有未排出的废气都将降低用于下一行程的空气量。 在压缩行程，排气口应当在进气口前关闭以使充气量最大，但如果两个过程是同一活塞控制的，发动机的几何形状回妨碍实现这一点。这种情况可在有排气阀的柴油机中实现。 在任何情况下，进气口都将在下止点后，以和下止点前开启时相同的角度关闭，即在下止点后130150关闭，排气口在同样的角度范围内关闭。 喷油在上止点前约1020开始，角度依转速而定。燃烧同四冲程机一样持续3050 柴油机结构（I） 一、 机座和机架 机座在大多数情况下是焊接结构，用螺栓固定在构成船舶双层底的底座上。它在横向借助于侧楔垫螺栓，在纵
8、向借助于端楔垫螺栓固定。 曲轴安放在机座横梁的轴承上，这些轴承称作主轴承。每个轴承由两块轴瓦组成，两块轴瓦由在机座上加工出的瓦座支撑，用双头螺栓和轴承盖固定。推力轴承位于发动机的尾部，可同机座制成一体也可同机座分开。 在机座上平面装有由若钢铸铁或锻钢制成的A字形机架，机架安装在机座的横梁上，并用螺栓固定。A形机架顶部有一个结实的框架结构叫扫气箱。该扫气箱分若干段，每段均带有垂直法兰，通过螺栓可将他们在链传动装置前13缸的部分连成一体，链传动装置后46缸的部分连成一体。链传动装置将曲轴和凸轮轴连在一起，封闭在链传动箱的壳体内。 二、 气缸和气缸盖 在扫气箱上部，每个气缸装有一个坚固的铸铁框架。这
9、些框架称作气缸体或冷却水套，并带有垂直法兰，与扫气箱一样，可用螺栓将各框架连成首尾两组。 基座、机架和气缸用长贯穿螺栓连到一起，形成一个较大的坚实结构，减少了使用时产生的变形及振动。 气缸套有铸铁制成，缸套表面有时镀铬。气缸套向下延伸到扫气箱。缸套与扫气箱顶部的密封由橡胶圈实现，橡胶圈安装在缸套上切削的环槽内。在气缸套伸入扫气箱内的部位有一列称为扫气口的开口。气口的高度是这样布置的，当活塞位于下止点时，活塞上沿刚好打开气口。气口在缸套上以大约20的倾角制成，其结果是使扫气旋转。 各缸顶部由特殊耐热钢制成的缸盖封闭。缸盖装在缸套顶部的平面上，并由机加工的凸肩定位。密封圈嵌入在缸盖锥形面时必须十分
10、小心。气缸盖和气缸套用旋入缸体中的双头螺栓固定。 缸套上有钻空用于润滑，新型的缸套在其最上部还有钻空用于冷却。 每个缸盖上有一个大型中心孔，用于安装排气阀，还有两到三个空用于装喷油器，还有些孔用来安装起动阀、安全阀、示功阀、以及作为排气阀冷却水腔的进出口。 阅读材料译文 ASULZER船用柴油机 SULZER RND-M 型柴油机是单作用、低速、二冲程、可逆转发动机。 每个汽缸的运动机构由活塞、活塞杠、连杆及所连接的单柄曲轴组成。 机座制成纵向箱形梁的双壁结构。A形框架安装在机座上，支撑机架和气缸体，整个机座、A形框架和气缸体组件用贯穿螺栓连在一起形成一个刚性结构。为了承受曲轴横向弯曲负荷，主
11、轴承盖由撑杆螺栓固定。这种强化结构对于承受经缸头传到柴油机结构上的燃烧负荷是必要的。曲轴是半组合式的，曲柄臂设计成部分平衡回转质量。气缸盖被制成单体件，并装有在中央的喷油器，起动空气阀、安全阀和示功阀。 废气驱动定压式的涡轮增压器提供扫气空气。采用回流式扫气并带有一台电动的自动运行的辅助鼓风机，以便低速和机动操作时使用。 润滑油供到低压和中压系统，低压系统向主轴承和其它轴承供油，十字头轴承由中压系统供油，铰链管把滑油送到十字头轴承。 汽缸、汽缸盖以及活塞由水冷却，伸缩套管把水送入活塞。 燃油喷射采用独立喷射系统，并且用Woodward型液压调速器调速。 RL型柴油机以RND-M型为基础，活塞行
12、程加长，提供更大的输出功率和更低的转速。其新特征包括带有推力轴承的单壁机座、活塞头和其他主要燃烧室部件钻空冷却，及用水在接近热表面的钻空中循环。 BSULZER RTA 型柴油机 SULZER RTA84C是一种典型的低速二冲程十字头式长行程现代柴油机。其缸径为840mm，行程为2400mm，转速为100r/min，4 到12缸间均产品，也可特别为大型快速集装箱船生产。其设计及结构和RTA2型系列相似，RTA2系列使汽缸尺寸降到380mm。机座是由钢板和一些铸件焊接构成的单壁深墙箱形结构，在焊接的坚实A形机架上装有各冷却缸套，它们由螺栓连成一体形成缸体。这些机件组成了柴油机的强固整体框架。整个
13、框架结构由贯穿螺栓垂直预紧。 缸套为铸铁合金。其上端是一坚实环台，坐落在汽缸体上，它承受很大的气体负载。缸套钻空冷却，可调节水流以维持合适的温度。缸套下端在扫气箱内，不进行冷却。在不同高度位置对气缸进行润滑以降低汽缸磨损率。 缸盖为坚实的锻钢件，采用钻孔冷却以减少热应力，并传递喷油器套的热量，使排气阀座用缸盖冷却水集中冷却。排气阀用84#镍铬钛合金（Ninonic80）制成，并通过安装在阀杆上的叶片转动。他靠液压开启，靠空气弹簧作用关闭，开启的液体压力来自凸轮驱动的操纵机构。 活塞带有合金钢的活塞头，并有5道压缩环，安装在镀铬的环槽内，活塞有一短的铸铁活塞裙。活塞用油冷却，既采用震荡冷却的方法
14、，也采用小型喷嘴注射的方法，将油通入紧贴活塞头底面和在活塞环槽背面的孔中。冷却油通过活塞杆中的钻孔从十字头的铰接杆供入和返回。活塞杆与单体十字头上表面相连，并连续贯穿整个下半部和上端轴承。上端轴承材料为白合金，靠压力油润滑。十字头导向滑块与十字头各端相连。 半总成式曲轴采用倒角内缩的曲柄以增大主轴承面积，主轴承盖由装在机架内的撑杆螺栓固定。凸轮轴由齿轮驱动，配有伺服器以便在倒车运行时给燃油泵和起动空气分配器重新定时。 高压油泵为凸轮驱动阀式油泵，带可变发火定时调节，以保持低速时高效燃烧。每个高压油泵向对称布置的装在缸盖上不进行冷却的三个喷油器供油。在不喷油时热的燃油在喷油器中循环。 这种柴油机
15、采用直流扫气，定压增压，带有高效的非冷却的透平增压器，在低速运行时，用两台高速电动辅助风机作补充。 柴油机结构（II） 一、 活塞及活塞杆 活塞由其下部一铸铁制成的活塞裙以及上部一耐热钢制成的活塞头组成。它们用螺栓连在一起并固定在活塞杆上。活塞部件相互间的位置由活塞头上车削的凹槽和定位销来固定。 每个活塞上装有56道活塞环，活塞环装在头部镀铬的环槽中。最上面的23道活塞环是带斜切口的窄环；紧接下去的2道活塞环是带有重叠搭口的宽环，最下面的那道环是刮油环。所有活塞环顶部和底部的外缘都稍有倒角，以便在新活塞环磨合期间缸套上留有油膜。 为了控制热应力，某些现代柴油机采用薄壁集中冷却活塞。在这种情况下
16、，活塞头内部有一插件，它用来对冷却液流导向，以增强传统的“鸡尾震荡”效应。 活塞杆从顶部法兰到与十字头中心相对位置处镗孔。一根长管从此孔插入几近孔底。管的外径小于孔的直径，因此在活塞杆和管子之间形成一个环形空间。 活塞杆的下端直径减小，插入十字头内孔中，并用螺帽将十字头与活塞杆紧固。活塞杆上装有定位销，以确保各部件的正确装配。 在十字头两端轴颈处，各装有十字头滑块。十字头滑块由发动机机架内的十字头导板导向。十字头滑块在十字头上的位置由定位销确定，并用锥头螺栓紧固在十字头上。EFI diesel engine works and system technologyMarine diesel en
17、gines is how does it work?The diesel engine is an internal combustion engine, fuel is sprayed into the high temperature and pressure of the combustion chamber ignition. The marine diesel engine is a board used in diesel engines. Its working principle is as follows: a certain amount of fresh air to b
18、e sucked or pumped into the cylinder and piston compression to high pressure. When the air is compressed, the temperature, he ignited the oil mist sprayed into the cylinder. The increase in the heat of the cylinder air for fuel combustion, the air expansion and forcing the engine piston acting on th
19、e crankshaft, with the attendant drives a propeller. Twice the fuel injection during the operation process is called a cycle of work. It consists of some of the procedures process. This cycle can be completed within a two stroke or four stroke. The four-stroke diesel engine duty cycle required four
20、separate piston stroke, that is, suction, compression, expansion and exhaust. If we inhale and exhaust stroke and the compression and expansion stroke combined, four-stroke diesel engine into a two-stroke diesel engines. Leave their itinerary at the bottom of two-stroke cycle piston bottom dead cent
21、er (BDC) upward run began, the inlet of the cylinder on the side of the scavenging port is open, the exhaust port is open. Compressed fresh air charge into the cylinder, blowing out the residual gas on a trip through the exhaust port. When the piston up to 1/5 of his trip, close the intake, exhaust
22、port, and then the air is compressed in the piston upward. When the piston up to trip the bottom of the top dead center (TDC), the air pressure and temperature rose to a high value. The injector to a very fine mist sprayed into the hot air, combustion gas to produce a higher pressure. With the expan
23、sion of the high-pressure gas, the piston is being pushed downstream until it opens the exhaust port, combustion gas discharge, the piston continues downstream until it opens the air inlet, and another cycle begins.Two-stroke diesel engine crankshaft revolution to produce a power stroke, power strok
24、e; in the four-stroke diesel engine crank two weeks to produce a power stroke. This is why two-stroke diesel engine can produce twice the power of the same size four-stroke diesel engine theory. Scavenging, however, is not sufficient and other losses, this advantage dropped to about 1.8 times. On bo
25、ard, each diesel engine to have his application. Low-speed (90 120 r / min), main propulsion diesel two-stroke. This low speed, the machine paddle do not need gear boxes. Four-stroke diesel engine (usually in the medium-speed operation, the speed in the 250 750r/min) for generators, and sometimes fo
26、r propulsion engines, gear box 90 120 r / min speed.The duty cycle diesel engine can be designed as a two-stroke cycle or four-stroke cycle, the two are explained as follows:Typical four-stroke cycle to turn the course of four-stroke cycle. Usually from the top dead center (TDC, ignition) to start d
27、rawing from the top dead center (TDC, sweep gas) begin to explain. The point is also called TDC TDC.See along the clockwise, starting forward, the exhaust valves are open (all modern four-stroke diesel engines have valve bodies). If the diesel engine is a natural ventilation or a small high-speed ma
28、chine with a the runoff pressurized gas, the valve overlap time, the two valves open at the same time a very short time. Close the exhaust valve at TDC (the ATDC) about 10 .Propulsion diesel engines and auxiliary power diesel engine operation following the vast majority of 1000r/min almost all turbo
29、charged, and are designed so that at this moment a lot of scavenging air throughout the flow in order to control the leaf temperature. In this case, the exhaust valve will remain open until the shut down of 50 60 after top dead center. With the piston in its inspiratory stroke out or the next stop p
30、oint downstream, it will inhale a large quantity of fresh air. Reaches the maximum, and compensation for the amount of air inhaled valve seated open reduction or the suction effect of inertia, the intake valve remains open, until the ending point of about 25 30 (145 155 BTDC). This process is called
31、 the intake valve closed. Filled the air and then upward piston compression to about 550 C. Depending on the type and speed of the diesel engine, about 10 20 BTDC, the fuel injector is injected into a finely atomized fuel. Ignition of fuel sprayed into the 2 7 (also according to the model), downstre
32、am of the piston in the expansion stroke, combustion period of 30 to 50 . The piston movement is usually conducive to the induction of air for combustion.Approximately 120 to 150 the ATDC, the exhaust valve opens (EVO). Select is quickly cylinder gas emissions to the exhaust pipe. This: (a) to retai
33、n enough energy to drive exhaust gas turbocharger; (b) reduce the cylinder pressure to the next stop point of the minimum to reduce the consumption of the pump exhaust stroke Qigong. Residual exhaust gas upstream of the piston driven, 70 80 BTDC, the intake valve open, so that outward flow of gas in
34、ertia coupled with a positive pressure differential (often in the cylinder in there), the air on the exhaust throughout the airflow to clean up the cylinder.If the diesel engine is natural ventilation, the intake valve opens at about 10 before TDC. Duty cycle to start again.Two-stroke cycleTypical t
35、wo-stroke cycle process, as its name within the meaning of the work cycle is completed within the crankshaft revolution.Two-stroke diesel engine is always a piston to open the inlet, the air intake downstream air entering the cylinder. The exhaust gas can be discharged and the adjacent exhaust ports
36、 controlled by the same piston (return sweep gas), or through the exhaust port of the cylinder on the other side of the discharge, or discharge (DC sweep gas through the exhaust valve).From TDC, the combustion has been carried out. 110 to 120 after top dead center, exhaust intake in the next 20 to 3
37、0 , the only point of 130 150 quickly purge the cylinder. By inertia to promote in this way to the sonic flow of exhaust air rapidly flows through the cylinder to a minimum of (gas) mixing, because all is not the exhaust air will reduce the amount of air for the next trip.In the compression stroke,
38、the exhaust port should be closed before the inlet to the aeration rate, but if the two processes is controlled by the same piston, and the geometry of the engine back to hinder the achievement of this. This situation in diesel engine exhaust valve.In any case, the air intake will be the next stop p
39、oint to open before the bottom dead point of view off, the next stop point 130 150 turn off the exhaust port is closed in the same angle in the range.The fuel injection before top dead center, about 10 20 angle according to speed. Burning with the four-stroke machine is the same for 30 50 Diesel eng
40、ine structure (I), Frame and rackBase in most cases welded structure, bolted to the base constitute the double bottom of the ship. In the horizontal by means of lateral wedge pad bolt in the vertical by means of the end of the wedge pad bolt.The crankshaft is placed in the base beam bearings, these
41、bearings are referred to as the main bearings. Each bearing consists of two bearing two bearing from the bearing seat of the processing on the base support, a fixed stud and bearing cap. The thrust bearing is located in the rear of the engine, with the base made of one with the base unit separately.
42、A shape made of cast iron or steel of if steel rack on the base plane is equipped with rack-mount on the base beam and bolted. A shaped top of the rack has a sturdy frame structure called scavenge. The sweep gas tank divided into several sections, each with a vertical flange in front of the chain dr
43、ive device through bolt a 3 cylinder parts fused to a chain drive device 4 to 6 cylinder part of the fused . The chain gear to the crankshaft and camshaft together, enclosed within the shell of the chain drive box.Second, the cylinder and cylinder headThe upper part of the scavenge each cylinder is
44、equipped with a sturdy cast iron frame. Framework known as the cylinder block cooling water jacket, and with a vertical flange, and scavenge available bolts to each frame into both the two groups.Pedestal, rack and cylinder connected to a long through bolts together to form a solid structure, reduci
45、ng the use of deformation and vibration.Cylinder liner made of cast iron cylinder liner surface is sometimes chrome plated. Cylinder liner extending down to scavenge. Liner and scavenging box at the top of the seal by the rubber ring, rubber ring is installed in the liner on the cutting of the ring
46、slot. One called scavenging port openings in the cylinder liner inserted into the sweep gas tank parts. The air inlet height is such arrangement, when the piston at bottom dead center, piston along just to open the air intake. The air inlet in the cylinder liner is made of about 20 angle, the result
47、 is the scavenging rotation.The top of each cylinder made of special heat-resisting steel cylinder head closed. Cylinder head mounted on the liner at the top of the plane, the orientation of the shroud by machining. Ring embedded in the cylinder heads of cone surface must be very careful. Cylinder h
48、ead and cylinder to apply spin into the stud in the cylinder is fixed.Liner on the drilling space is used for lubrication, the new liner at the top of air drilling for cooling.Each cylinder head has a large center hole used to install the exhaust valve, as well as two to three empty for loading injector, and also some of the holes used to install the starter valve, safety valves, indicator valve, as well as The exhaust valve cooling water chamber of import and export.Reading material translationA. SULZER marine diesel engineOf SULZER the RND-M type diesel engine