Summary of the invention
On this basis, an object of the present invention is to provide a kind of large-scale, with the two stroke diesel engine of heavy oil work, it overcomes or has reduced above-mentioned problem at least.By claim 1, provide a kind of large-scale, two-stroke, many cylinders, the diesel engine of crosshead and realized this purpose, described diesel engine has one can be with the fuel injection system of heavy fuel oil work, described fuel injection system comprises a low pressure pipeline that is connected to a low pressure source, a middle pressure pipe road that is connected to potential source in, a fuel under high pressure that is connected to a high-pressure fuel source is total to rail, at least one Fuelinjection nozzle of each cylinder, a plurality of to the mobile control valve of controlling from common rail to Fuelinjection nozzle, control valve is connected to the injection pipe of Fuelinjection nozzle inlet, described control valve is connected to common rail with described injection pipe, thereby when the fuel injection beginning, described injection pipe is pressurizeed, and be connected to described low pressure pipeline or middle pressure pipe road, thereby when fuel sprays end, described injection pipe is carried out step-down, described fuel valve is provided with the outlet that links to each other with described low pressure pipeline, and the control valve unit that is used for described pressure pipe road is connected to described injection pipe, be used for the heavy fuel oil circulation when motor does not turn round.
When not turning round injection pipe is connected to the control valve unit in middle pressure pipe road, the circulation fuel oil can be provided to injection valve, keep being total to the high pressure in the rail simultaneously by being arranged on motor.Thereby motor can remain on stand-by state, and injection valve can be incubated and need not to be incubated or Electric heating appliance simultaneously.Thereby motor can be constructed and keep in repair (need not remove thermal insulation apparatus for maintenance) simply, and can be more suitable for remaining under the stand-by state.
Preferably, control valve is pressed branching of pipes during injection pipe is connected to, be used for when fuel sprays end the injection pipe step-down, simultaneously, the control valve unit that is used for described pressure pipe road is connected to described injection pipe comprises that two are provided with safety check on the contrary, and described two safety check are arranged in the branch of leading to control valve in pressure pipe road in each.
The branch of leading to control valve in pressure pipe road can comprise a forked part with two parallelpipeds in described, in any that is arranged in this two parallelpiped in described two opposite safety check that are provided with.In any case all need a safety check, to guarantee a back-pressure, if this back-pressure prevents that control valve and injection valve are owing to abrupt pressure reduction is subjected to too high impact---do not have pressure controlled valve, then this abrupt pressure reduction can take place.Another safety check is used for preventing that high pressure fuel from flowing to the pressure pipe road at fuel between injection period.Thereby, between middle pressure pipe road and injection pipe, formed one simple and be connected reliably, the heavy fuel oil that is used for the motor stopping period circulates.
Preferably, control valve is connected to low pressure pipeline with injection pipe, be used for when fuel sprays end the injection pipe step-down, and preferably, when motor did not turn round, described injection pipe was connected to described middle pressure pipe road by a safety check, makes heavy fuel oil to circulate, described safety check allows fuel therefrom to flow to injection pipe in the pressure pipe road, but does not allow fuel pressure pipe road from injection pipe flows to.Of the present invention this becomes example also provides a simple and reliable connection at the motor stopping period between middle pressure pipe road and injection pipe.
Control valve can be connected to low pressure pipeline with injection pipe, with when fuel spray to finish to the injection pipe step-down, described injection pipe can by an electrical control valve be connected to described in the pressure pipe road, its between middle pressure pipe road and injection pipe ready-made one make and can connect by circuit at motor stopping period heavy fuel oil.Of the present invention this becomes example also provides a simple and reliable connection at the motor stopping period between middle pressure pipe road and injection pipe.
Preferably, control valve is connected to low pressure pipeline with injection pipe, be used for when fuel sprays end the injection pipe step-down, and preferably, the branch of leading to control valve of described low pressure pipeline includes a spring-loaded safety check or other pressure controlled valve, it makes the pressure in the component that leads to control valve of low pressure pipeline keep greater than the pressure in the low pressure pipeline, and one of them electrical control valve is connected to the branch of leading to control valve of described low pressure pipeline with pressure pipe road in described, makes and can circulate at motor stopping period heavy fuel oil.Of the present invention this becomes example also provides one effectively to connect between middle pressure pipe road and injection pipe.
Fuel valve can comprise a jet blower and be used for high-pressure liquid from the inlet Guide spray mouth of injection valve and with the control valve unit of hydraulic fluid from the outlet of the inlet Guide spray valve of injection valve.Thereby high pressure fuel is guided between injection period to nozzle at fuel, and simultaneously, in the cyclic process of heavy fuel oil, middle compression ignite oil is guided to low pressure pipeline.
Control valve can be such type: it is controlled by solenoid valve.
Other purpose, feature, advantage and performance according to large two-stroke diesel engine of the present invention will become clear by detailed description.
Embodiment
Fig. 1 and 2 show respectively one according to the sectional view of the motor 1 of the present invention's one preferred implementation and longitudinal sectional view (for single cylinder).Motor 1 is a crosshead diesel engine a kind of one-way flow, low speed, two stroke, the cross hair style, and it can be used as the propulsion system of steamer or the motive force in the power station.These motors have the cylinder that 3 to 14 series connection are provided with usually.Motor 1 forms by a base plate 2 that has the main bearing of bent axle 3.
Bent axle 3 is half composite types.Half composite type is made by forging the iron and steel crank of making or casting, and described crank is connected with main journal by shrink-fit.
Base plate 2 can be according to the convenience degree of making and integrated or be divided into the suitable several sections of size.Base plate comprises sidewall and has the welding beam of bearing support (cross girder).Crossbeam is also referred to as " transverse beam " in the prior art.Oil-collecting disk 58 is welded to the bottom of base plate 2, and collects the oil that returns from enforced lubricating and cold oil system.
Connecting rod 8 is connected to cross head bearing 22 with bent axle 3.Cross head bearing 22 is directed between the vertical guide plate 23.
The A shape frame-box 4 of a Welding Design is installed on the base plate 2.Frame-box 4 is Welding Design.Exhaust side in frame-box 4 is provided with the safety valve that is used for each cylinder, and is provided with the big hinged door that is used for each cylinder in the camshaft side of frame-box 4.Crosshead guide plate 23 is integrated in the frame-box 4.
A cylinder seat 5 is installed in the top of frame-box 4.Stay-bolt 29 links together base plate 2, frame-box 4 and cylinder seat 5 and described structure is kept together.Stay-bolt 29 is tightened by hydraulic jack.
That cylinder seat 5 is cast as at last is one or more, have an integrated camshaft frame 25, and perhaps it is designed to be welding.One according to this mode of execution becomes routine (not shown), electrically controls the actuating of outlet valve, and do not have camshaft 28 or camshaft frame 25, but have the hydraulic system of an electrical control.
Cylinder seat 5 is provided with access cover, is used for from camshaft side cleaning gas-swept space and detection scavenge port and piston ring.It has formed gas-swept space with cylinder sleeve 6.The opening side of scavenge air receiver 9 is fixed to cylinder seat 5.In the bottom of cylinder seat, have a piston rod stuffing box, piston rod stuffing box is provided with the scraper ring in the space that scavenging seal ring and the expense gurry of preventing be penetrated into frame-box 4 and base plate 2, thereby has protected all bearings in this space.
Piston 13 comprises piston head and piston skirt.Piston head is by heat-resisting steel manufacturing, and has four circular grooves, all is coated with hard chromium on the upper surface of described circular groove and lower surface.
Piston rod 14 is connected to crosshead 22 by four screws.Piston rod 14 has two coaxial holes (difference is seen in the drawings), and described hole combines with oil cooling service pipe and formed the entrance and exit of the cold oil of piston 13.
Cylinder sleeve 6 is by cylinder seat 5 carryings.Cylinder sleeve 6 is by the alloy cast iron manufacturing, and is suspended on cylinder seat 5 by a flange that is arranged in the below.The topmost part of described cover is held by the cast iron cooling collar.Cylinder sleeve 6 has the boring (not shown), to be used for cylinder lubrication.
Cylinder belongs to the type of one-way flow and has the scavenging port 7 that is arranged in gas tank, and it is by sweeping air-capacitor device 9 (Fig. 1) supply with the scavenging by turbosupercharger 10 (Fig. 1) supercharging.
Motor is equipped with one or more turbosupercharger 10, is arranged on the motor tail end for 4-9 the described turbosupercharger 10 of cylinder engine, is arranged on the exhaust side of motor for the described turbosupercharger 10 of motor of 10 or more a plurality of cylinders.
The air inlet of turbosupercharger 10 directly comes from engine compartment, passes through the baffler (not shown) of turbosupercharger.From turbosupercharger 10, gas directs into the scavenging port 7 of cylinder sleeve 6 by an outlet pipe (not shown), air-cooler (not shown) and scavenge air receiver 9.
Motor is provided with the scavenge blower (not shown) of electric driving.The suction side of blower is connected to the gas-swept space behind the air-cooler.Dispose the safety check (not shown) between air-cooler and scavenge air receiver, when the auxiliary blower supply gas, described safety check automatically cuts out.Auxiliary blower plays help to the turbocharger compressor under low load or the medium load.
Fuel valve 50 is installed on the cylinder head 12 with one heart.When compression stroke ended up, injection valve 50 was under high pressure spurted into fuel in the burning cavity 15 with the form of tiny mist by its jet blower.Outlet valve 11 medially is installed in the top of cylinder in cylinder head 12.When expansion stroke ends up, outlet valve 11 was opened before engine piston 13 moves down by scavenging port 7, wherein be positioned at piston 13 tops, be in the combustion gas of burning cavity 15 by 16 outflows of an exhaust passage, and the pressure in the burning cavity 15 reduces, and described exhaust passage 16 feeds a degassing container 17.When piston 13 moved up, outlet valve 11 was closed once more.Outlet valve 11 is hydraulically powered.
Fig. 3 shows first mode of execution according to fuel injection system of the present invention.Fig. 3 only shows two cylinders of motor, makes accompanying drawing simple, so that be explained and illustrated.Yet, should be appreciated that motor 1 can comprise the cylinder more than two.Fuel injection system comprises a heavy fuel oil storage tank 27, and heavy fuel oil at high temperature is stored in wherein.Heavy fuel oil under low pressure (preferably 2 to 10 crust between) be sucked into a low pressure pipeline 32 (in order to back up, always being equipped with at least two supply pumps, but for simplicity, only shown in the drawings) by a low pressure feed pump 30.Low pressure pipeline 32 comprises the branch 33 that outlet a plurality of and fuel valve 50 links to each other.Low pressure feed pump 30 replenishes the corresponding fuel of fuel respective numbers that is consumed with motor 1.
Low pressure pipeline 32 comprises a branch at 34 places, this branch is connected to the inlet of recycle pump 36, in order to back up, always is equipped with at least two recycle pumps, but for simplicity, one only shown in the drawings.Pressure pipe road 38 during recycle pump 36 is drawn onto heavy fuel oil under medium pressure, and the pressure difference between low pressure pipeline and the middle pressure pipe road is remained on 2 cling between 10 crust, preferably, the ducted pressure of middle pressure clings between 16 crust 6.The inlet of middle pressure pipe road 38 bifurcateds feeding high pressure fuel pump 40 (at least two high-pressure service pumps always are equipped with in order to back up,, but for simplicity, one only shown in the drawings; And, have the high voltage startup pump of a unshowned electric driving usually, be used for when engine start altogether rail to pressurizeing).
High pressure fuel pump 40 under high pressure is that fuel common rail 42 is supplied with heavy fuel oil.Pressure in the fuel common rail may fluctuate, but preferably, the pressure in the fuel common rail 42 remains on 600 and clings between 1200 crust.Service 44 is branched to each cylinder from fuel common rail 42.Control valve 46 is connected to injection pipe 48 with each service 44.Each injection pipe 48 is connected to the inlet (alternatively, can only be provided with or more than two the fuel valve 50 that is associated with each cylinder) of two fuel valves 50 that are associated with each cylinder.
Control valve 46 (it can be a Proportional valve) is electric control, and receives control signal by line 56 from unshowned electric control unit.Control valve 46 has a first portion---it is connected to injection pipe 48 with service 44---and a second portion---its by the branch 39 in middle pressure pipe road 38 injection pipe 48 is connected in pressure pipe road 38.When needs began to relevant cylinder injection fuel, control unit command control valve 46 was taked primary importance, and when the fuel that needs finish associated cylinder sprayed, control unit command control valve 46 was taked the second place.Control unit is from a tachometer (not shown) received signal, the zero hour and the finish time of spraying with the fuel of judging each cylinder.
A spring-loaded safety check 58 guarantees that the pressure release of injection pipe 48 when fuel sprays end can be very not unexpected, thereby makes fuel valve 50 and control valve 46 can not damage because of too high impact force.Typically, spring-loaded safety check 58 remains on back-pressure about about 100 crust.Except spring-loaded safety check, can also adopt the pressure controlled valve (not shown).
The branch 39 in middle pressure pipe road 38 is fork-shapeds, thereby it includes two parallel pipe sections 61 and 62.Above-mentioned safety check 58 is arranged in the pipe section 61, and allow from control valve 46 to the flowing of pressure pipe road 38, and another safety check 59 is arranged in the pipe section 62, and allows pressure pipe road 38 therefrom towards the flowing of control valve 46, and is used for the heavy fuel oil circulation when motor stops.
When motor stopped, rail 42 can keep pressurization when the needs engine standby altogether.If do not need engine standby, then altogether rail 42 can the step-down by the release pipeline 67 under reduction valve 66 controls, and described reduction valve 66 can open or close the connection that forms between rail 42 and the low pressure pipeline 32 altogether under the instruction of control unit.When motor stopped, the pressure during recycle pump 36 keeps in the pressure pipe road made it than high about 4 crust of the pressure in the low pressure pipeline 32 that is kept by supply pump 30.In this case, control valve 46 remains on the second place, and middle pressure pipe road 38 is connected to injection pipe 48.
Fuel valve 50 is provided with pressure-sensitive inner valve member (not shown), described valve member is connected to the inlet of fuel valve 50 outlet of fuel valve when low pressure or middle hydraulic fluid are transported to the inlet of fuel valve 50, and when high-pressure liquid is transported to the inlet of fuel valve, the described jet blower that pressure-sensitive inner valve member is connected to the inlet of fuel valve 50 fuel valve.The outlet of fuel valve 50 is connected to the branch 33 of low pressure pipeline 32.Thereby, can flow through injection valve 50 and be discharged to low pressure pipeline 32 from injection valve 50 of the middle ballast fuel oil of carrying via safety check 59, control valve 46 and injection pipe 48 by middle pressure pipe road 38 by the outlet of injection valve, thus keep the temperature of fuel valve 50 and do not have air (de-aerated).
In a preferred embodiment, the circulation loop that is formed by middle pressure pipe road 38 and low pressure pipeline 32 is provided with steam insulation heating plant and adiabatic apparatus.
Pressure difference during a side/backpressure valve 69 maintains between pressure pipe road 38 and the low pressure pipeline 32.
Fig. 4 shows according to second mode of execution of the present invention (for practical purpose, only show a cylinder, yet, be to be understood that, this mode of execution can be used in the motor that comprises two or more cylinders), wherein control valve 46 is by a solenoid valve 70 controls, and described control valve 46 is instructed by an order line 56 by control unit.The position of control valve 46 is determined by hydro cylinder 72.First pressure chamber 75 that has less effective piston area in cylinder 72 connects by a piston and piston rod and control valve 46 is pressed to the second place, and in this second place, injection pipe 48 is connected to the branch 44 of common rail 42.Second pressure chamber 77 that has big effective piston area in cylinder 72 is pressed to a primary importance with control valve 46, in this primary importance, and the branch 39 in pressure pipe road 38 during injection pipe 48 is connected to.The branch 44 of rail directly is connected to first pressure chamber 75 altogether, and is connected to second pressure chamber 77 by a limiting device 79.Branch 44 is connected to low pressure pipeline 32 by limiting device 79, another limiting device 82 and solenoid valve 70.Only when solenoid valve 70 was shown in an open position, the connection between branch 44 and the low pressure pipeline 32 just can be opened.When solenoid valve 70 was opened according to the instruction of control unit, heavy fuel oil began from branch 44 by two limiting devices 79 and 82 and flow to low pressure pipeline 32 by solenoid valve 70.Limiting device 79 mobile of flowing through formed a pressure drop, and it causes pressure in the pressure chamber 77 to be lower than pressure in the pressure chamber 75 significantly.Thereby cylinder 72 is forced into control valve 46 in the primary importance, and wherein branch 44 is connected to injection pipe 48 and the injection of beginning fuel.When in case solenoid valve 70 cuts out according to the instruction of control unit, pressure drop in limiting device 79 both sides is eliminated, and the big piston area of pressure chamber 77 causes cylinder 72 that control valve 46 is depressed into the second place, thereby injection pipe 48 is connected to the branch 39 in middle pressure pipe road 38.
When motor stopped, control valve 46 also was positioned on the second place, and the heavy fuel oil of depressing in being in can flow to the inlet of fuel valve 50 by safety check 59, by control valve 46 and injection pipe 48.This fuel valve 50 is left in the outlet of the fuel valve of heavy fuel oil by being connected to low pressure pipeline 32 branches 33.
Fig. 5 shows according to the 3rd mode of execution of the present invention (for practical purpose, only show a cylinder, yet, should be appreciated that this mode of execution can be used in the motor that comprises two or more cylinders), and itself and mode of execution shown in Figure 3 are similar.Yet when control valve 46 was on its second place, injection pipe 48 was connected to the branch 33 of low pressure pipeline 32.For fear of pressurization fuel valve 50 and control valve 46 are caused damage, in this mode of execution, spring-loaded safety check 58 is arranged in the branch 33 of low pressure pipeline 32.Between control valve 46 and safety check 58, the branch 39 in middle pressure pipe road 38 is connected to the branch 33 of low pressure pipeline.The circulation valve 81 of an electrical control (a single circulation valve can be used for all cylinders) is arranged in the branch 39.When motor did not turn round, circulation valve 81 and when engine running, was moved to its closed position in the control of the instruction that comes from control unit under the control of the instruction that comes from control unit and move to its open position.
When circulation valve 81 is shown in an open position, the ballast fuel oil that is arranged in pipeline 39 can flow into the inlet of Fuelinjection nozzle 50 by control valve 46 and injection pipe 48, and leave this Fuelinjection nozzle by the outlet of Fuelinjection nozzle, arrive at the branch 33 of low pressure pipeline 32.
Fig. 6 shows according to the 4th mode of execution of the present invention (for practical purpose, only show a cylinder, yet, should be appreciated that this mode of execution can be used in the motor that comprises two or more cylinders), and itself and mode of execution shown in Figure 3 are similar.Yet the branch 39 in middle pressure pipe road 38 is not forked, and only includes spring-loaded safety check 58.As an alternative, pressure pipe road 38 during injection pipe 48 branches to by a pipeline 41 is without control valve 46.Safety check 59 is arranged in the pipeline 41, pressure pipe road 38 in getting back to avoid high pressure fuel return pipe road 41.On the other hand, when motor stopped, middle ballast fuel oil therefrom pressure pipe road 38 flow to the inlet of injection pipe 48 and fuel valve 50 through piping 41 and safety check 58.Fuel valve 50 is left in fuel valve 50 outlets of the branch 33 of heavy fuel oil by being connected to low pressure pipeline 32.
Fig. 7 shows according to the 5th mode of execution of the present invention (for practical purpose, only show a cylinder, yet, should be appreciated that this mode of execution can be used in the motor that comprises two or more cylinders), and itself and mode of execution shown in Figure 3 are similar.Yet control valve 46 is connected to injection pipe 48, is connected to pipeline 33 ' on its second place, is provided with a spring-loaded safety check 58 in this pipeline 33 '.Pipeline 33 ' by safety check 59 and bifurcated to middle pressure pipe road 38.In the power operation process, when control valve 46 was positioned at the second place, the pressure in the injection pipe 48 controllably discharged with spring-loaded safety check 58 by pipeline 33 '.When motor 1 does not turn round, in the ballast fuel oil therefrom flow to the branch 33 of low pressure pipeline 32 via the outlet of inlet, fuel valve 50 and the fuel valve of safety check 59, branch 33 ', control valve 46, injection pipe 48, fuel valve in pressure pipe road 38, make heavy fuel oil can cycle through injection valve 50.
Term in the claim " comprises " member of not getting rid of other.The term " one " or " one " that are used for claim do not get rid of a plurality of situations.
The label that is used for claim is not used in scope of the present invention is limited.
Though for illustrative purposes and invention has been described, should be appreciated that these details only are for purpose of description, and those skilled in the art can change therein and can not depart from category of the present invention.