Make the method and the internal-combustion engine of internal combustion engine operation with exhaust gas recirculation
Technical field
The present invention relates to a kind of method that is used to make the internal-combustion engine with exhaust gas recirculation, the especially turbo charged diesel engine that drives with heavy oil to realize operation.The invention still further relates to a kind of internal-combustion engine in addition.
Background technique
By putting into practice known turbo charged internal-combustion engine with exhaust gas recirculation.For turbo charged internal-combustion engine with exhaust gas recirculation, the release in the turbine of exhaust gas turbocharger of the exhaust flow of internal-combustion engine, the turbine driven compressor of exhaust gas turbocharger wherein, this compressor will be input to the combustion air compression of internal-combustion engine.In the upstream of the turbine of exhaust gas turbocharger, in the exhaust flow of internal-combustion engine, take out shunting, this shunting feeds back in the internal combustion air that has compressed and mixes with it.Pressurized air and waste gas shunting also mix in the upstream of cylinder of internal combustion engine thus in the upstream of internal-combustion engine.The waste gas that feeds back plays the effect of inert gas, reduces the combustion peak temperature in the cylinder of internal-combustion engine and therefore reduce to generate harmful matter.
Especially for diesel engine with heavy oil work, this is problematic by known exhaust gas recirculation in the practice, this is because include a large amount of pitch, ash content and sulphur in heavy oil, therefore when heavy oil combustion, produce residue, these residues shunting that the quilt of exhaust flow feeds back with may be deposited on the parts of guiding combustion air after the combustion air that has compressed mixes, thereby can make these functions of components of infringement.
This may cause continuous, the unacceptable operation deterioration of internal-combustion engine, and causes the very loaded down with trivial details upkeep operation on internal-combustion engine, especially cleaning process.
Summary of the invention
Therefore task of the present invention is to propose a kind of new method and a kind of new-type internal-combustion engine that is used to make the internal combustion engine operation with exhaust gas recirculation.This task is by being used to make the method for the internal combustion engine operation with exhaust gas recirculation to finish according to of the present invention, wherein from the exhaust flow of internal-combustion engine, take out shunting, this shunting is cooled off in gaseous effluent also to be fed back to reduce the harmful matter of internal-combustion engine, it is characterized in that, the exhaust gas recirculation of the described shunting through cooling off directly enters into the cylinder of internal-combustion engine, the shunting through cooling off that makes described exhaust flow is in the cylinder that is input to quartastroke engine during the suction stroke, make in the suction stroke of each cylinder of internal-combustion engine, when at least one combustion air INO, the direction motion of piston in described cylinder in the cylinder from upper dead center towards lower dead centre, this of each cylinder or each combustion air suction valve were closed before arriving lower dead centre, wherein after this or each combustion air suction valve are closed, during suction stroke, promptly when making pressure in the cylinder reach the stress level in the exhaust gas recirculation owing to the expansion of combustion air in cylinder or be reduced under the stress level in the exhaust gas recirculation, the shunting through cooling of exhaust flow is input in each cylinder, when the pressure in the cylinder had reached the stress level in the exhaust gas recirculation, the shunting through cooling that just stops exhaust flow fed back in each the cylinder
Especially be suitable for the diesel engine that drives with heavy oil according to method of the present invention, according to said method, the shunting that is fed back according to exhaust gas recirculation of exhaust flow is non-directly to import in the cylinder of internal-combustion engine indirectly in other words.In according to method of the present invention, waste gas is mixed in the upstream of cylinder of internal-combustion engine with the combustion air that has compressed, the member of guiding combustion air is not polluted with regard to not needing.
According to a kind of favourable improvement project of the present invention, the shunting through cooling off of exhaust flow is in the cylinder that is introduced into quartastroke engine during the suction stroke, make in the suction stroke of each cylinder of internal-combustion engine-this or each the combustion air suction valve of direction motion-each cylinder from upper dead center towards lower dead centre when its piston is when at least one combustion air INO in this cylinder be closed before arriving lower dead centre, wherein after this or each combustion air suction valve are closed, during suction stroke, exactly when making pressure in the cylinder reach the stress level in the exhaust gas recirculation owing to the expansion of combustion air in cylinder or be reduced under the stress level in the exhaust gas recirculation, the shunting through cooling of exhaust flow entered in each cylinder.
When the pressure in the cylinder had reached the stress level in the exhaust gas recirculation, the recirculation that the shunting through cooling of exhaust flow is entered in each cylinder stopped.
According to the internal-combustion engine with exhaust gas recirculation of the present invention, it is characterized in that, the exhaust gas recirculation of the shunting through cooling off is directly entered in the cylinder of internal-combustion engine, each cylinder disposes at least one waste gas suction valve respectively, and this waste gas suction valve can be unlocked and cut out according to the method described in the present invention.
The present invention gives preferred improvement project.The embodiment of the invention is described in detail with reference to the accompanying drawings, but is not limited thereto.Accompanying drawing is depicted as:
Description of drawings
Fig. 1: be used to illustrate the P-V figure that makes the method for internal combustion engine operation according to of the present invention with exhaust gas recirculation.
Reference numerals list
1 operation point
2 operation points
3,3 ' operation point
4 operation points
5 operation points
6 operation points
7 operation points
8 operation points
10 high-pressure sections
11 ventilation parts
Embodiment
The present invention relates to a kind of method that internal-combustion engine, especially a kind of turbo charged diesel engine that drives with heavy oil are moved, this internal-combustion engine has exhaust gas recirculation.In this internal-combustion engine, make the exhaust flow of internal-combustion engine be input to turbocharger, wherein make exhaust flow release in the turbine of turbocharger.The compressor of the turbine drives exhaust gas turbocharger of exhaust gas turbocharger, this compressor make combustion air or the pure air compression that is input to internal-combustion engine.In exhaust gas recirculation, in the exhaust flow of internal-combustion engine, take out shunting in the upstream of the turbine of exhaust gas turbocharger, wherein make this shunting cooling and being fed back in gaseous effluent to reduce the harmful matter of internal-combustion engine.Wherein according to the present invention, make the exhaust gas recirculation through the shunting of cooling of exhaust flow directly enter into the cylinder of internal-combustion engine.
Below according to the example of quartastroke engine among Fig. 1, to being described in detail according to method of the present invention, wherein Fig. 1 has represented so-called P (pressure)-V (flow) figure of the cylinder of quartastroke engine.The work cycle of the cylinder of quartastroke engine is divided into four strokes, just so-called suction stroke, compression stroke, working stroke and exhaust stroke.
P-V figure shown in Figure 1 is divided into two parts in principle, just a so-called high-pressure section 10 and a so-called ventilation part 11.High-pressure section 10 has comprised compression stroke and working stroke, and wherein compression stroke is extended between operation point 1 and 2, and working stroke is extended between operation point 2 and 3,3 and 3 ', 3 ' and 4 and 4 and 1.Ventilation part 11 has comprised exhaust stroke and suction stroke, and wherein exhaust stroke is between operation point 1 and operation point 5, and suction stroke is then between operation point 6 and operation point 1.
For quartastroke engine, carry out during the suction stroke of each cylinder of internal-combustion engine according to the exhaust gas recirculation in the cylinder that directly enters into internal-combustion engine of the present invention, wherein in suction stroke, the piston of each cylinder is the motion of the direction towards lower dead centre UT (operation point 1) from upper dead center OT (operation point 6) when at least one combustion air INO.During suction stroke, before reaching lower dead centre UT, 7 places close in the operation point for this of each cylinder or each combustion air suction valve.
At this or each combustion air suction valve after 7 places, operation point close, the piston of each cylinder continues the direction motion to lower dead centre UT, wherein the combustion air that herein is sucked in the cylinder expands, so the pressure in the cylinder descends from the pressure p L of the combustion air that is sucked.
8 places, operation point in suction stroke, pressure in the cylinder reaches the stress level pA in the exhaust gas recirculation, wherein when the pressure in the cylinder had reached the stress level pA in the exhaust gas recirculation or drop under the stress level pA in the exhaust gas recirculation, the shunting of the cooling of exhaust flow was just directly imported in each cylinder of internal-combustion engine indirectly in other words by non-.
For this reason during suction stroke, at least one is attached troops to a unit in the waste gas INO of cylinder, exactly, when perhaps directly the pressure in cylinder has reached the stress level pA in the exhaust gas recirculation, perhaps after the time goes up pressure in cylinder and is reduced under the stress level pA the exhaust gas recirculation.
When the pressure in each cylinder has reached the stress level pA in the exhaust gas recirculation again, the feedback that waste gas is non-indirectly directly to be entered in the cylinder of internal-combustion engine in other words just is terminated, wherein this or in suction stroke before reaching lower dead centre UT, along with reaching of lower dead centre UT, perhaps also after reaching lower dead centre UT, also during compression process, can realize thus.This or each are attached troops to a unit closes in the waste gas suction valve of each cylinder.
Because in the zone of cylinder, almost there is not the pressure difference of what part, so can exhaust gas recirculation is non-directly to be entered in the cylinder of internal-combustion engine indirectly in other words making in the zone of the cylinder head of each cylinder or in the zone in cylinder liner.
According to a kind of favourable improvement project of the present invention, before being incorporated into gaseous effluent, it is transported to the waste gas washing apparatus from the shunting that exhaust flow is derived, so that reduce the danger that gaseous effluent is polluted.
Although the present invention at first is suitable for making the diesel engine operation that drives with heavy oil, the present invention also can be used in gasoline engine (Otto-Brennkraftmaschine).This method fuel type used with driving internal-combustion engine has nothing to do.
As mentioned above, in order to make in the directly non-in other words cylinder that is incorporated into internal-combustion engine indirectly of waste gas, each cylinder all is furnished with at least one waste gas suction valve.The waste gas suction valve can or mechanically be controlled by the mode of cam or electricity consumption or electronics, so that make its opening and closing according to mode of the present invention.