5. 燃油應按柴油機發(fā)火的次序進行分配
6. 起始噴射和終止噴射的迅速控制
MTU柴油機傳統(tǒng)的機械調(diào)速器
傳統(tǒng)的機械調(diào)速器種類很多,用于直列式油泵和噴油嘴系統(tǒng)、分配式油泵和噴油嘴系統(tǒng)等,有機械飛錘式或液壓式等。機械調(diào)速器的性能有很大的局限性,一般用于500KVA以下的小型發(fā)電機組。
MTU柴油機電子調(diào)速器
噴油的控制由電子調(diào)速器實現(xiàn),但執(zhí)行機構與傳統(tǒng)的機械調(diào)速器一樣,即油門,齒條位置決定油門的大小。與傳統(tǒng)的機械調(diào)速器相比,電子調(diào)速器反應更靈敏、更精確、更多功能,可實現(xiàn)恒定轉速控制。
MTU柴油發(fā)動機則采用更為先進的、擁有微處理器的電子控制噴油調(diào)速系統(tǒng),作為MDEC發(fā)動機管理系統(tǒng)的一部分,我們將在下一章專門介紹。
第七節(jié)MTU柴油機的配氣機構
MTU柴油發(fā)動機的配氣機構是實現(xiàn)發(fā)動機進氣過程和排氣過程的控制機構。其作用是按照配氣正時的要求,在規(guī)定的時刻開啟和關閉進、排氣門,以保證汽缸排除廢氣,吸進新鮮氣體,使工作循環(huán)不間斷地進行。
氣門組件
氣門組件包括氣門、氣門導管、氣門彈簧和彈簧座及其鎖緊裝置等零件。
MTU柴油機進排氣系統(tǒng)
1. 進氣系統(tǒng)和空氣濾清器
2. 排氣系統(tǒng)和消聲器
MTU柴油機渦輪增壓器
渦輪增壓器結構和原理:禍輪增壓器由渦殼、噴嘴環(huán)、渦輪和轉子軸組成。徑流式渦輪增壓器工作時,柴油機徘出的廢氣進入增壓器的渦輪殼后,沿著增壓器的轉子軸的軸線的垂直平面(即徑向)流動。這是由于當氣流通過噴嘴時,MTU柴油機|MTU柴油機的燃油系統(tǒng)維修技術|MTU柴油機的燃油系統(tǒng)資料|MTU柴油機的燃油系統(tǒng)維修服務商|一部分壓能和熱能轉換為動能,獲得高速氣流。由噴嘴環(huán)出來的高速氣流按一定方向流入葉輪,在葉輪中被迫沿著彎曲通道改變流動方向,在離心力的作用下,氣流質點投向葉片凹面,壓力增加而相對速度降低;葉片凸面上則相對速度提高而壓力降低,因此,作用在葉片凹凸面上的氣流合力(即壓力差)在渦輪軸上形成推動葉片旋轉的力矩,因而從葉輪流出的廢氣經(jīng)由渦輪中心沿軸排出。中型柴油機大多采用徑流式渦輪增壓器。
第八節(jié)MTU柴油機柴油機的潤滑系統(tǒng)
柴油機運行時,各運動零件相對運動表面之間必然會產(chǎn)生摩擦。對于金屬表面來說,若直接摩擦,其摩擦力是很大的,這不僅使柴油機的內(nèi)部功率損耗增加,零件工作表面迅速磨損,而且由于摩擦時產(chǎn)生大量熱量,零件溫度極高,甚至可能使某些零件表面熔化,使柴油機無法工作。因此,凡是有相對運動的零件必須加以潤滑,也就是在摩擦表面覆蓋一層潤滑油(俗稱機油),使固體摩擦成為液體摩擦,以減小摩擦阻力,降低內(nèi)部功率損耗,減輕機件磨損,延長柴油機的使用壽命。柴油機的潤滑由潤滑系統(tǒng)不實現(xiàn)。
MTU柴油機潤滑系統(tǒng)的主要部件
1. 機油泵
2. 機油濾清裝置
3. 機油冷卻裝置
4. 低油壓自動保護停機裝置
5. 指示裝置
第九節(jié)MTU柴油機柴油機的冷卻系統(tǒng)
柴油機運行時,燃油在燃燒室內(nèi)燃燒產(chǎn)生大量的熱量,使汽缸內(nèi)氣體溫度高達1800~2500℃,大約有三分之一左右的熱量被柴油機的零件所吸收,尤其直接與高溫氣體接觸的機件,如活塞、汽缸蓋、汽缸、氣門等機件強烈受熱,若不采取適當?shù)睦鋮s措施,將會造成嚴重后果:受熱后的機件,溫度很高,強度下降,甚至燒壞變形,破壞正常的間隙,潤滑油也會因溫度升高而變稀,失去應有的潤滑作用,加劇運動機件的磨損和變形,甚至引起潤滑油燃燒和機件的粘結,使柴油機無法繼續(xù)工作,因此,為保證柴油機正常運行,必須進行冷卻。但是,由于柴油機是依靠壓燃方式工作的,需要有一定的汽缸溫度,才能使柴油充分燃燒,因此,柴油機的冷卻必須適度。若冷卻過度,一方面熱量散失過多,使轉變?yōu)橛杏霉Φ臒崃繙p少,另一方面溫度過低,不利于可燃混合氣的形成和燃燒。
由此可知,柴油機工作溫度過高或過低都會降低它的動力性和經(jīng)濟性。冷卻系統(tǒng)的是保持柴油機在最適宜的溫度狀態(tài)下工作,以獲得良好的經(jīng)濟性、動力性和耐久性。
水冷卻系統(tǒng)的主要部件
1. 水泵
2. 散熱水箱
3. 風扇
4. 水溫調(diào)節(jié)與節(jié)溫器
5. 水溫表
6. 防凍液
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