6. 起始喷射和终止喷射的迅速控制
MTU柴油机传统的机械调速器
传统的机械调速器种类很多,用于直列式油泵和喷油嘴系统、分配式油泵和喷油嘴系统等,有机械飞锤式或液压式等。机械调速器的性能有很大的局限性,一般用于500KVA以下的小型发电机组。
MTU柴油机电子调速器
喷油的控制由电子调速器实现,但执行机构与传统的机械调速器一样,即油门,齿条位置决定油门的大小。与传统的机械调速器相比,电子调速器反应更灵敏、更精确、更多功能,可实现恒定转速控制。
MTU柴油发动机则采用更为先进的、拥有微处理器的电子控制喷油调速系统,作为MDEC发动机管理系统的一部分,我们将在下一章专门介绍。
第七节MTU柴油机的配气机构
MTU柴油发动机的配气机构是实现发动机进气过程和排气过程的控制机构。其作用是按照配气正时的要求,在规定的时刻开启和关闭进、排气门,以保证汽缸排除废气,吸进新鲜气体,使工作循环不间断地进行。
气门组件
气门组件包括气门、气门导管、气门弹簧和弹簧座及其锁紧装置等零件。
MTU柴油机进排气系统
1. 进气系统和空气滤清器
2. 排气系统和消声器
MTU柴油机涡轮增压器
涡轮增压器结构和原理：祸轮增压器由涡壳、喷嘴环、涡轮和转子轴组成。径流式涡轮增压器工作时,柴油机徘出的废气进入增压器的涡轮壳后,沿着增压器的转子轴的轴线的垂直平面(即径向)流动。这是由于当气流通过喷嘴时,MTU柴油机|MTU柴油机的燃油系统维修技术|MTU柴油机的燃油系统资料|MTU柴油机的燃油系统维修服务商|一部分压能和热能转换为动能,获得高速气流。由喷嘴环出来的高速气流按一定方向流入叶轮,在叶轮中被迫沿着弯曲通道改变流动方向,在离心力的作用下,气流质点投向叶片凹面,压力增加而相对速度降低；叶片凸面上则相对速度提高而压力降低,因此,作用在叶片凹凸面上的气流合力(即压力差)在涡轮轴上形成推动叶片旋转的力矩,因而从叶轮流出的废气经由涡轮中心沿轴排出。中型柴油机大多采用径流式涡轮增压器。
第八节MTU柴油机柴油机的润滑系统
柴油机运行时,各运动零件相对运动表面之间必然会产生摩擦。对于金属表面来说,若直接摩擦,其摩擦力是很大的,这不仅使柴油机的内部功率损耗增加,零件工作表面迅速磨损,而且由于摩擦时产生大量热量,零件温度极高,甚至可能使某些零件表面熔化,使柴油机无法工作。因此,凡是有相对运动的零件必须加以润滑,也就是在摩擦表面覆盖一层润滑油(俗称机油),使固体摩擦成为液体摩擦,以减小摩擦阻力,降低内部功率损耗,减轻机件磨损,延长柴油机的使用寿命。柴油机的润滑由润滑系统不实现。
MTU柴油机润滑系统的主要部件
1. 机油泵
2. 机油滤清装置
3. 机油冷却装置
4. 低油压自动保护停机装置
5. 指示装置
第九节MTU柴油机柴油机的冷却系统
柴油机运行时,燃油在燃烧室内燃烧产生大量的热量,使汽缸内气体温度高达1800~2500℃,大约有三分之一左右的热量被柴油机的零件所吸收,尤其直接与高温气体接触的机件,如活塞、汽缸盖、汽缸、气门等机件强烈受热,若不采取适当的冷却措施,将会造成严重后果：受热后的机件,温度很高,强度下降,甚至烧坏变形,破坏正常的间隙,润滑油也会因温度升高而变稀,失去应有的润滑作用,加剧运动机件的磨损和变形,甚至引起润滑油燃烧和机件的粘结,使柴油机无法继续工作,因此,为保证柴油机正常运行,必须进行冷却。但是,由于柴油机是依靠压燃方式工作的,需要有一定的汽缸温度,才能使柴油充分燃烧,因此,柴油机的冷却必须适度。若冷却过度,一方面热量散失过多,使转变为有用功的热量减少,另一方面温度过低,不利于可燃混合气的形成和燃烧。
由此可知,柴油机工作温度过高或过低都会降低它的动力性和经济性。冷却系统的是保持柴油机在最适宜的温度状态下工作,以获得良好的经济性、动力性和耐久性。
水冷却系统的主要部件
1. 水泵
2. 散热水箱
3. 风扇
4. 水温调节与节温器
5. 水温表
6. 防冻液
MTU diesel engine fuel system
Overview of MTU diesel engine fuel system
The diesel engine fuel injection system diesel engine control center or "heart". Many different types of fuel injection system design or model, its role is in accordance with the diesel engine process needs a certain amount of diesel fuel, to a certain degree of pressure within a certain time to make diesel aerosol sprayed into the cylinder with compressed air formed uniform combustible mixture combustion.
MTU diesel engine fuel injection system must meet the following requirements:
Injection timing
(2) measurement of the fuel injection quantity (measurement)
(3) the fuel must be pressurized
Fuel must be atomized
5 diesel engine ignition of the fuel should be the order of allocation
6. The initial injection and rapid control of the termination of injection
MTU diesel engines traditional mechanical governor
Traditional types of mechanical governor for inline pumps and injector system, the allocation of oil pump and injector system, a mechanical flying hammer or hydraulic. The performance of the mechanical governor has great limitations, generally used for small generating units below 500KVA.
MTU diesel engine electronic governor
Fuel injection control by electronic governor, but the executive body with the traditional mechanical governor, that is, throttle, rack position to determine the size of the throttle. Compared with the traditional mechanical governor electronic governor response is more sensitive, more accurate, more features, can achieve a constant speed control.
MTU diesel engine is more advanced, with microprocessor electronic control fuel injection speed control system as part of the MDEC engine management system, we have devoted in the next chapter.
Section VII MTU diesel engines Valve
MTU diesel engine valve train is the control mechanism of the engine intake process and exhaust process. Its role is in the prescribed time in accordance with the requirements of the valve timing to open and close the intake and exhaust valves to ensure that the cylinder rule out the exhaust, inhaling the fresh gas, so that the duty cycle uninterrupted.
Valve components
The valve components including valves, valve guides, valve spring and spring seat and its locking devices and other parts.
MTU diesel engine intake and exhaust systems
1 intake system and air filter
2 exhaust system and muffler
MTU diesel engine turbochargers
Turbocharger structure and principles of composition: curse wheel turbocharger volute and nozzle ring and turbine and rotor shaft. Run-of-turbochargers work, the diesel engine the irresolute out of the exhaust gas into the turbocharger's turbine shell, flows along the vertical plane of the axis of the rotor shaft of the turbocharger (ie, radial). This is when the air flow through the nozzle, part of the pressure and thermal energy is converted to kinetic energy, access to high-speed airflow. High-speed airflow from the nozzle ring according to a certain direction into the impeller, the impeller was forced to change the flow direction, along the curved channel under the influence of centrifugal force, the air particles to invest in the leaves concave, the pressure increase in relative velocity reduction; leaves convex on the relative speed and lower pressure, therefore, the role of airflow in the leaves concave and convex surface force (pressure difference) form promote the torque of the rotating blades in the turbine shaft, and thus the exhaust gas outflow from the impeller along the axis through the center of the turbine discharge. Medium-sized diesel engines mostly run-of-turbocharger.
Section VIII, MTU diesel engine diesel engine lubrication systems
The diesel engine run time, the moving parts between the relative surface is bound to produce friction. For metal surfaces, if the direct friction, the friction is great, which not only the increase in internal power loss of the diesel engine parts work surface quickly wear and tear, and a lot of heat due to friction and part temperature is extremely high, and may even make Some parts of the surface melting, the engine does not work. Therefore, any relative motion of the parts must be lubricated friction surface is covered with a layer of lubricant (commonly known as oil), the solid friction fluid friction, to reduce friction, lower internal power loss, reduce mechanical wear and tear, extend the service life of diesel engines. Diesel engine lubricated by the lubricating system.
MTU diesel engine lubrication system components
(1) Oil Pump
(2) oil filtering device
(3) oil cooling device
Low oil pressure automatic protection shutdown device
5 indicating device
Section IX, MTU diesel engine diesel engine cooling system
When the diesel engine running, the fuel combustion in the combustion chamber to produce large amounts of heat, so that the cylinder gas temperature up to 1800 to 2500 ℃, about about one-third of the heat absorbed by the diesel engine parts, especially parts directly in contact with high temperature gas , such as piston, cylinder head, cylinder, valve and other parts of the strong heat, failure to take appropriate cooling measures, will lead to serious consequences: the parts, high temperature heat, the intensity decreased, and even burn deformation, disruption of normal the gap, the lubricating oil due to temperature rise thinning, loss of proper lubrication effect, exacerbated by the wear and deformation of the moving parts, or even cause the lubricating oil combustion and mechanical bond, the engine can not continue to work, so In order to ensure the normal operation of the diesel engine, must be cooled. However, because diesel engines rely on compression ignition cylinder temperature to make diesel full combustion, therefore, the cooling of the diesel engine must be moderate. If excessive cooling, on the one hand excessive heat loss, make the change to reduce the heat to useful work, on the other hand the temperature is too low, is not conducive to the formation and combustion of the combustible mixture.
Therefore, the diesel engine operating temperature is too high or too low will reduce its power and economy. The cooling system is to keep the diesel engine in the optimum temperature conditions, in order to get a good economy, power and durability.
The main components of the water cooling system
1 for pump
(2) Radiator
3 fan
Adjust the water temperature with section thermostat
(5) Water temperature gauge
6. Antifreeze
