航空发动机系统燃油系统.ppt

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1、航空发动机系统航空发动机系统中国民航大学航空电气系中国民航大学航空电气系孙兆荣孙兆荣2014.4 5 5 燃油系统燃油系统缩写词缩写词ECU HMUFMVFRVVSVVBVBSVTBV2014-4航空自动化学院航空电气系2HPTACC LPTACCHPSOV2014-4航空自动化学院航空电气系3发动机燃油系统发动机燃油系统功用：是在各个工作状态下将清洁的、无蒸汽的、经过增压的、计量好的燃油供给发动机。飞机的不同飞行阶段（滑跑、起飞、爬升、巡航、下降、进近、复飞等）需要不同的推力（或功率），对应着发动机不同的工作状态，也就是说需要供给发动机不同的燃油量。动力装置在地面和空中有其安全工作范围，燃油

2、量的供给必须在安全限制之内。发动机控制应该避免发动机工作中出现超温、超转、喘振、贫油或富油熄火、超压和超扭。2014-4航空自动化学院航空电气系4CFM56-7B燃油系统燃油系统2014-4航空自动化学院航空电气系5CFM56-7B燃油系统燃油系统 供给燃油供发动机燃烧和伺服系统操作。飞机燃油系统供油给发动机燃油分配系统。发动机燃油分配系统的主要部件：燃油泵组件从飞机燃油系统接受燃油供给增压的燃油至液压机械装置的伺服和计量部分燃油滤清洁液压机械装置的燃油IDG滑油冷却器在燃油流至液压机械装置之前，加热燃油的装置：IDG滑油冷却器燃油滑油热交换器伺服燃油加温器发动机燃油分配系统2014-4航空自

3、动化学院航空电气系6CFM56-7B燃油系统燃油系统燃油泵-负责供油和增压，部件壳体内常常包括增压级和主级。发动机燃油分配系统部件燃油泵2014-4航空自动化学院航空电气系7CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油泵CFM56-7B燃燃油油泵泵2014-4航空自动化学院航空电气系8CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油泵是依靠叶轮作旋转运动，使流经叶轮的液体增加动能和压力能，在叶轮后的扩压器中再将液体的动能部分滞止，转化为压力能。这类泵有离心泵、汽心泵、螺旋泵。容积式泵叶轮式泵是依靠泵的抽吸元件作相对运动，交替改变元件间的自由容积进行吸油、排油的。供油

4、量取决于元件一次循环运动中自由容积变化的大小。在一定的供油量下，泵根据出口处的液体流动阻力来建立压力。如：柱塞泵、齿轮泵、旋板泵（叶片泵）。2014-4航空自动化学院航空电气系9CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油泵柱塞式燃油泵柱塞式燃油泵：变量泵，供油量不仅取决于转速还取决于斜盘角度，转速不变时，供油量通过改变斜盘角度容易调节。2014-4航空自动化学院航空电气系10CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油泵齿轮式燃油泵齿轮式燃油泵：定量泵，当转速不变时，供油量通过旁通回油调节。即齿轮泵的供油量始终高于需油量，超出需要的油量返回油泵进口。2014-

5、4航空自动化学院航空电气系11CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油喷嘴功用功用：执行燃油雾化或汽化的任务，以保证燃油快速燃烧。2014-4航空自动化学院航空电气系12CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油喷嘴燃油喷嘴及安装2014-4航空自动化学院航空电气系13CFM56-7B燃油喷嘴（FUEL NOZZLE）The fuel nozzles spray fuel into the combustion chamber and ensure good light-off capability and efficient burning at all

6、 engine power settings.There are twenty fuel nozzles,which are installed all around the combustion case area,in the forward section.Basically,all fuel nozzle models are similar,provide the same operational performances,and are mounted and connected to the engine in an identical manner.However,four n

7、ozzles located on either side of the spark plugs,have a wider primary spray angle.CFM56-7B燃油系统燃油系统2014-4航空自动化学院航空电气系14CFM56-7B燃油喷嘴（FUEL NOZZLE）The wider spray angle is incorporated to improve altitude re-light capability.Blue color band on the 16 regular fuel nozzles.Natural color band on the 4 wide

8、r spray fuel Nozzles.CFM56-7B燃油系统燃油系统2014-4航空自动化学院航空电气系15CFM56-7B燃油系统燃油系统CFM56-7B燃油喷嘴（FUEL NOZZLE）At 15 psig,the fuel opens the check valve.It is sent to the central area of the metering set which calibrates the spray pattern of the primary fuel flow(narrow angle).When the fuel pressure reaches 120

9、psig,it opens the flow divider metering valve and the fuel goes through the outer tube of the support to another port in the metering set.This ports calibrates the spray pattern of the secondary fuel flow(wider angle of 125).2014-4航空自动化学院航空电气系16CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油喷嘴单油路喷嘴双油路喷嘴它有一个内腔，使燃油产生漩

10、涡，还有一个固定面积的雾化孔。这种燃油喷嘴，在较高的燃油流量，即在较高的燃油压力时，能提供良好的雾化质量；但是，在低的发动机转速和特别在高空要求的油压较低，这种喷嘴就很不适合。双油路喷嘴有中心孔和外圈孔。中心孔处理较低的燃油流量，较大的外圈孔随着燃油压力的增加供应较高的燃油流量。采用增压活门将燃油分配到不同的油路。随燃油流量和压力增加，增压活门移动，逐渐使燃油进入外圈油路和外圈油孔，给组合的两个油路供油。双油路喷嘴2014-4航空自动化学院航空电气系17CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油喷嘴雾化雾化：燃油流被破碎成极细的油珠的过程，液滴越细，蒸发越快。喷雾的形状是雾化

11、程度的重要指示。漩涡的程度和喷嘴燃油的压力是良好雾化的重要因素。2014-4航空自动化学院航空电气系18CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油喷嘴空气雾化喷嘴使喷射的燃油携带一部分燃烧室的一股空气。它用空气的高速代替燃油的高速引起雾化。为防止发动机停车后喷嘴积碳，在燃油喷嘴中有单向活门。高压切断活门关闭后当燃油总管压力降低，单向活门关闭，确保没有燃油从总管中因重力进入燃烧室。2014-4航空自动化学院航空电气系19CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-流量分配器（BSV）功用功用：保证所有喷嘴流过等量的燃油。补偿在低燃油压力下油路中的重力压头。某些燃烧系

12、统使燃油在进入燃烧区时汽化。燃油流量分配器将燃油导入主、副燃油总管。2014-4航空自动化学院航空电气系20CFM56-7B燃油系统燃油系统CFM56-7B燃烧分级活门（BSV）The burner staging valve enables the fuel delivery to 10 fuel nozzles to be shut off.This increases the local richness and prevents the engine from flaming out during decelerations.Used in decel to keep the fuel

13、 flow above the lean flame-out limit.Cuts 10 of the 20 engine fuel nozzles.2014-4航空自动化学院航空电气系21CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-伺服燃油加热器目的：目的：加温燃油防止结冰，堵塞油路。加温的方法可用发动机的热滑油以及压气机的引气。燃油加热有限制，在起飞、进近、复飞这些关键的飞行阶段不能使用引气加温燃油，这是为了防止出现熄火的可能。2014-4航空自动化学院航空电气系22CFM56-7B燃油系统燃油系统发动机燃油分配系统部件IDG滑油冷却器It cools the IDG oil.

14、The IDG oil cooler is located on the fan case at the 7 oclock position.The interfaces are:The fuel supply and return lines.The oil supply and return lines.2014-4航空自动化学院航空电气系23CFM56-7B燃油系统燃油系统发动机燃油分配系统部件IDG滑油冷却器发动机燃油系统May,2012中国民航大学航空电气系24The purpose:to cool the scavenged oil with cold fuel,through c

15、onduction and convection,inside the exchanger where both fluids circulate.The servo fuel heater is another heat exchanger which uses engine scavenge oil as the heat source to warm up fuel in the fuel control system.This prevents ice particles entering sensitive servo mechanisms.发动机燃油分配系统部件燃油/滑油热交换器发

16、动机燃油系统May,2012中国民航大学航空电气系25发动机燃油分配系统部件燃油/滑油热交换器May,2012中国民航大学航空电气系26CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-液压机械装置（HMU）May,2012中国民航大学航空电气系27It transforms electrical signals sent from the ECU into hydraulic pressures in order to actuate various actuators used in engine control.The HMU has different functions：It

17、provides internal calibration of fuel pressures.It meters the fuel flow for combustion.It provides the fuel shut-off and fuel manifold minimum pressurization levels.It by-passes the return of unused fuel.It provides mechanical N2 over speed protection.It delivers the correct hydraulic power source t

18、o various engine fuel equipment.CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-液压机械装置（HMU）May,2012中国民航大学航空电气系28To manage and control the engine systems and equipment,the HMU houses two different internal subsystems,which are:The servo-mechanism area,including the pressure regulation system,the servo flow regulation sy

19、stem,solenoid valve and electro-hydraulic servo valves to supply fuel to the various valves and actuators of the engine.The fuel metering system,including the fuel metering valve,the head sensor,the pressurizing and shut-off valve,the by-pass valve,and the over speed governor system.CFM56-7B燃油系统燃油系统

20、发动机燃油分配系统部件-液压机械装置（HMU）May,2012中国民航大学航空电气系29To achieve all the different engine functions,the HMU is fitted with:6 Electro-Hydraulic Servo Valves(EHSV)for the control of:FMV,VSV,VBV,TBV,HPTACC,LPTACC.1 solenoid(S)for airframe shut-off solenoid valve signal generation(this solenoid is not controlled

21、by the EEC,but by the A/C Start lever&Fire switches).1 resolver(R),to track the FMV position.1 switch for the over speed governor.1 set of switches,connected to A/C,for position feedback of the pressurizing and shut-off valve.CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-液压机械装置（HMU）May,2012中国民航大学航空电气系30CFM56-7B燃油系统燃油

22、系统发动机燃油分配系统部件-液压机械装置（HMU）May,2012中国民航大学航空电气系31CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-液压机械装置（HMU）2014-4航空自动化学院航空电气系32CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油回油活门（FRV）The FRV（FUEL RETURN VALVE）returns part of the by-pass fuel,flowing through the IDG oil cooler,back to the A/C fuel tank.FRV部部件件2014-4航空自动化学院航空电气系33CFM56-7B燃

23、油系统燃油系统发动机燃油分配系统部件-燃油回油活门（FRV）2014-4航空自动化学院航空电气系34CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油回油活门（FRV）2014-4航空自动化学院航空电气系35CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油回油活门（FRV）2014-4航空自动化学院航空电气系36CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油回油活门（FRV）2014-4航空自动化学院航空电气系37CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油回油活门（FRV）Inside the FRV,cold fuel from the

24、fuel pump LP stage outlet is mixed with the warm fuel returning from the IDG oil cooler.This is to limit the temperature of the fuel going back to the A/C tank.A shut-off system is provided to isolate the engine fuel circuit from the A/C fuel tank return circuit.The FRV is fuel operated and electric

25、ally controlled through the ECU control logic.The control logic of the FRV is dependent on the engine oil temperature(TEO).In case of failure of the TEO sensor,FRV positioning cannot be calculated based on the sensor.In this case,a default value for the oil is set(178C)and the FRV opens.2014-4航空自动化学

26、院航空电气系38CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油回油活门（FRV）Above a certain engine oil temperature,the ECU commands a LOW return fuel flow to the A/C.If the engine oil temperature continues to increase,the ECU commands a HIGH return fuel flow to the A/C.The engine oil temperature thresholds depend on the fuel in

27、ner tank temperature,and A/C ground or flight conditions.On ground,if the engine oil temp reaches 90C,only the LOW return fuel flow is redirected to the A/C,until the oil temperature drops to 78C.In flight conditions,LOW return fuel flow may be selected at the same engine oil temperature as on groun

28、d.Following LOW,HIGH return fuel flow is selected,if the engine oil temperature reaches 95C.It is deselected when the temperature drops below 85C.The FRV is opened to the second level(HIGH)during a FADEC ground motoring test.2014-4航空自动化学院航空电气系39CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-燃油回油活门（FRV）FRV will be clos

29、ed in any of the following cases:When N2 speed is below 50%during engine start.When the metered fuel flow is greater than 5520 pph.(T/O).With engine shut-down.When the aircraft management system sends an inhibit signal(fuel temp high+fuel tank full).When flight/ground status is not available.2014-4航

30、空自动化学院航空电气系40CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-可变几何尺寸控制系统To maintain satisfactory compressor performance over a wide range of operation conditions.Commanded by the ECU and operated through HMU hydraulic signals.Consists of:a VBV system,located downstream from the booster.a VSV system,located within the fi

31、rst stages of the HPC.To establish a more suitable air flow,VBVs are installed on the contour of the primary airflow stream,between the booster and the HPC.2014-4航空自动化学院航空电气系41CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-可变几何尺寸控制系统At low speed,they are fully open and reject part of the booster discharge air into the

32、 secondary airflow,preventing the LPC from stalling.At high speed,the VBVs are closed.2014-4航空自动化学院航空电气系42CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-VBV2014-4航空自动化学院航空电气系43CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-VBVThe purpose of the Variable Bleed Valve(VBV)system is to regulate the amount of air discharged from the booster

33、into the inlet of the HPC.To eliminate the risk of booster stall during low power conditions,the VBV system by-passes air from the primary airflow into the secondary.the ECU calculates the VBV position and the HMU provides the necessary fuel pressure to drive a fuel gear motor,through a dedicated se

34、rvo valve.VBV 作动筒是一个活塞式作动筒。HMU 输送伺服燃油压力至活塞的筒侧和杆侧移动活塞至指令的位置。2014-4航空自动化学院航空电气系44CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-VBV2014-4航空自动化学院航空电气系45CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-VBV VBV SYSTEM OPERATION:Using engine parameters,the ECU calculates the VBV position.The ECU commands the HMU to drive the gear motor with pre

35、ssured fuel.The gear motor actuate the master bleed valve.The stop mechanism mechanically limits the opening and closing of the valve.The master bleed valve drives the 11 variable bleed valves,through a series of flexible shafts,which ensure that the VBVs remain fully synchronized throughout their c

36、omplete stroke.A feedback rod is attached between the master bleed valve and the feedback transducer,which transforms the angular position of the master bleed valve into an electrical signal for the ECU.2014-4航空自动化学院航空电气系46CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-VSV2014-4航空自动化学院航空电气系47CFM56-7B燃油系统燃油系统发动机燃油分配系统部

37、件-VSVThe VSV system positions the HPC stator vanes to the appropriate angle to optimize HPC efficiency.It also improves the stall margin during transient engine operations.The VSV position is calculated by the ECU using various engine parameters,and the necessary fuel pressure is delivered by the HM

38、U.The variable stator stages consist of:Inlet Guide Vanes(IGV),Variable Stator Vane(VSV)stages1-2-3,2 actuators and 2 feedback sensors(LVDT).2014-4航空自动化学院航空电气系48CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-VSVThe VSV control law depends on altitude(high,low)and the status(steady state/transient).According to sensor

39、signals,the EEC computes the appropriate VSV actuator position.The two actuators,located at the 2 and 8 oclock positions on the HPC case,move the 4 actuation rings to change the angular position of the vanes.Two electrical feedback sensors(LVDT),one per actuator,transmit the VSV position to the EEC

40、to close the control loop.The right hand side feedback sensor is connected to channel A and the left hand side feedback sensor to channel B.VSV control loop:2014-4航空自动化学院航空电气系49CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-VSVVSV control loop:2014-4航空自动化学院航空电气系50CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-TBV2014-4航空自动化学院航空电气系51CFM5

41、6-7B燃油系统燃油系统发动机燃油分配系统部件-TBVThe Transient Bleed Valve(TBV)system improves the HPC stall margin during engine starting and rapid acceleration.Using engine input parameters,the ECU logic calculates when to open or close the TBV to duct HPC 9th stage bleed air,in order to give optimum stability for tran

42、sient mode operations.The 9th stage bleed air is ducted to the LPT stage 1 nozzle,providing an efficient start stall margin.The ECU,working through the HMU,controls the TBV position.2014-4航空自动化学院航空电气系52CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-TBVThe TBV system consists of:uThe TBV,located on the HPC case,between

43、 the 7 and 8 oclock positions.uThe 9th stage air IN and OUT pipes.2014-4航空自动化学院航空电气系53CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-TBVThe TBV operational actuation is as follows:Start:open.Idle:closed.Accel from idle to 76%-80%N2:open.Above 80%:closed.The EEC monitors TBV system position through two LVDTs(channel A

44、and channel B).2014-4航空自动化学院航空电气系54CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-TBV2014-4航空自动化学院航空电气系55CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-HPTACC2014-4航空自动化学院航空电气系56CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-HPTACCThe HPTACC system optimizes HPT efficiency through active clearance control between the turbine rotor and shroud and reduces c

45、ompressor load during starting and transient engine conditions.The HPTCC system uses bleed air from the 4th and 9th stages to cool down the HPT shroud support structure in order to:maximize turbine efficiency during cruise.minimize the peak EGT during throttle burst.2014-4航空自动化学院航空电气系57CFM56-7B燃油系统燃

46、油系统发动机燃油分配系统部件-HPTACC2014-4航空自动化学院航空电气系58CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-HPTACCThis is a closed loop system,using the valve position as feedback.The EEC uses various engine and aircraft sensor information to take into account the engine operating range and establish a schedule.A thermocouple,located on

47、the right hand side of the HPT shroud support structure,provides the EEC with temperature information.To control the temperature of the shroud at the desired level,the EEC calculates a valve position schedule.This valve position is then sent by the EEC active channel to the HPTACC Electro-Hydraulic

48、Servo Valve(EHSV),within the HMU.2014-4航空自动化学院航空电气系59CFM56-7B燃油系统燃油系统发动机燃油分配系统部件-HPTACCThe servo valve modulates the fuel pressure sent to command the HPTACC valve.Two sensors(LVDT),connected to the actuator,provide the EEC with position feedback signals and the EEC changes the valve position until

49、the feedback matches the schedule demand.The HPTACC control law depends on HP rotor temperature(hot/cold)and is calculated versus N2.May,2012中国民航大学航空电气系60发动机燃油分配系统部件-LPTACCThe LPTACC system uses fan discharge air to cool the LPT case during engine operation and controls the LPT rotor to stator clear

50、ances.It also protects the turbine case from over-temperature by monitoring the EGT.This ensures the best performance of the LPT at all engine ratings.The LPTACC system is a closed loop system,which regulates the cooling airflow sent to the LPT case,through a valve and a manifold.The LPTACC valve is