KR102181690B1 - A large two-stroke uniflow scavenged gaseous fueled engine - Google Patents

Abstract

Large two-stroke turbocharged single-flow scavenging internal combustion engines include: A combustion chamber divided into a cylinder liner (1), a piston (10) and a cylinder cover (22), a scavenging port (18) disposed in the cylinder liner (1), at least one exhaust valve (4) disposed in the cylinder cover (22) ), at least one fuel valve (30, 31) disposed on the cylinder liner (1) for injecting gaseous fuel into the combustion chamber, a pressurized gas fuel supply source (40), and pressurized gas without a calorific value to the fuel valve (30). It includes a supply source 44 to supply, and the engine is configured to inject both gaseous fuel and gas without calorific value into the combustion chamber through the fuel valves 30 and 31.

Description

Large two-stroke single-flow scavenging gas fuel engine {A LARGE TWO-STROKE UNIFLOW SCAVENGED GASEOUS FUELED ENGINE}

The present invention relates to a large turbocharged two-stroke internal combustion engine, in particular a large two-stroke single-flow scavenging internal combustion engine including a crosshead operated on gaseous fuel.

Large two-stroke turbocharged single-flow internal combustion engines with crossheads are used, for example, as the propulsion of large marine vessels or as the main driving force of power plants. In addition to their enormous size, these two-stroke diesel engines are constructed differently from any other internal combustion engine in several respects. The exhaust valve weight of these diesel engines is up to 400 kg, the piston diameter is up to 100 cm, and the maximum working pressure in the combustion chamber is typically several hundred bar. The forces associated with this high pressure level and piston size are enormous.

A large two-stroke turbocharged internal combustion engine that operates on gaseous fuel injected by a fuel valve placed in the middle of the length of the cylinder liner, i.e., an engine that injects gaseous fuel during the upstroke of the piston starting around the time the exhaust valve is closed. The mixture of gaseous fuel and scavenging is compressed and ignited by means of ignition timing, such as pilot oil injection. Thus, the piston compresses the gaseous fuel and the desired mixture, resulting in a knocking risk. In the art, this type of knocking is referred to as “diesel” knocking.

The problem of diesel knocking can be reduced by ensuring that the combustion chamber charge is as homogeneous as possible. However, obtaining a homogeneous scavenging and gaseous fuel charge is not easy. Because the opportunity during the engine cycle from the point when the exhaust valve is closed to the top dead center (TDC) is relatively short, only a very short period of the engine cycle (usually when the crankshaft angle is 20-40 degrees) can be used to obtain a homogeneous supercharge. Because. In comparison, in a four-stroke engine, gaseous fuel and charge air can be reliably mixed in the intake system, or at least during most of the stages of opening the inlet valve, typically during a crankshaft angle of 0 to 160 degrees.

The relatively short chance of engine cycles available to obtain homogeneous supercharge increases the problem of avoiding diesel knocking in large two-stroke diesel engines.

Inhomogeneous supercharging of gaseous fuel and supercharged air inside the combustion chamber increases the risk of diesel knocking, which can result in serious damage to the engine.

The prior art attempted to solve the engine knocking problem in the following manner.

DK1779361 discloses a large single-flow scavenging two-stroke engine having a piston moving inside the cylinder liner, a cylinder head including an exhaust valve, and a scavenging port circumferentially disposed within the cylinder liner. Several fuel injection valves are distributed circumferentially around the cylinder liner above the scavenging port. Fuel is injected at a crank angle of at least 90° before TDC.

The DK1766118 B1 discloses another large single-flow scavenging two-stroke engine in which gaseous fuel is injected from the scavenging port and flows into the combustion chamber. Further, a water jet nozzle is provided on the cylinder head. Water is injected into the combustion chamber during compression to reduce the temperature of the fuel/air mixture to prevent knocking.

However, it was found that the above solution did not work satisfactorily in effectively preventing knocking in large two-stroke compression ignition internal combustion engines.

Therefore, there is a need to improve fuel injection in large engines to effectively protect the engine from damage due to knocking.

Accordingly, it is an object to provide a large single-flow scavenging two-stroke engine operating on gaseous fuel, capable of preventing or at least reducing knocking.

The above and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, description and drawings.

According to a first aspect, a large two-stroke turbocharged single-flow scavenging internal combustion engine includes a cylinder liner, a combustion chamber divided into a piston and a cylinder cover, a scavenging port disposed on the cylinder liner, at least one exhaust valve disposed on the cylinder cover, and gaseous fuel. At least one fuel valve disposed in the cylinder liner and a pressurized exhaust gas supply source for the fuel valve, and the internal combustion engine is injected into the combustion chamber by at least one fuel valve. It is configured to simultaneously inject both gaseous fuel and exhaust gas into the combustion chamber through at least one of the fuel valves to increase the momentum of the substance.

The purpose of the injected exhaust gas is to increase the momentum of the injected substance into the combustion chamber by injecting a reactive substance that does not change the calorific value of the substance injected into the combustion chamber. Increasing the momentum improves the mixing of the gaseous fuel and the scavenging, thereby making the charging more homogeneous and reducing the risk of knocking.

Accordingly, the injected exhaust gas is a reactive material, but does not change the calorific value of the material injected into the combustion chamber (gas fuel and injected exhaust gas). However, the additional momentum generated by the exhaust gas injection increases the total momentum of the injected material, thereby reducing the risk of knocking or premature combustion.

Momentum is the product of mass m (kg) and velocity v (m/s).

Therefore, the total momentum of the substance injected into the combustion chamber is the sum of the product of the mass of the injected fuel and the velocity of the injected fuel and the mass of the injected exhaust gas multiplied by the velocity of the injected air and/or the exhaust gas.

The speed of the gaseous fuel injected is limited to the speed of sound. The mass of fuel injected during an injection event/per engine cycle is determined by the engine load. It is generally not possible to increase the momentum any further after the gaseous fuel reaches the speed of sound.

However, the present inventors have reached the insight that the injected mass increases by injecting exhaust gas in addition to the injected gaseous fuel, and the momentum can be increased by increasing the momentum accordingly. Thus, the momentum increases by high-speed injection of additional gas.

The inventors have reached the insight that additional exhaust gases further reduce the risk of knocking by lowering the charge temperature in the combustion chamber during compression.

According to a first possible embodiment of the first aspect, gaseous fuel and exhaust gas are simultaneously injected into the combustion chamber from at least one fuel valve as a mixture.

According to a second possible embodiment of the first aspect, the gaseous fuel and the exhaust gas are mixed inside at least one fuel valve.

According to a third possible embodiment of the first aspect, the gaseous fuel and the exhaust gas are mixed upstream of the at least one fuel valve.

According to a fourth possible embodiment of the first aspect, the engine comprises a common supply line for supplying exhaust gas and gaseous fuel to at least one fuel valve.

According to a fifth possible embodiment of the first aspect, the gaseous fuel and the exhaust gas are injected simultaneously from the hole of the at least one fuel valve nozzle.

According to a sixth possible embodiment of the first aspect, the engine has a separate supply line for supplying exhaust gas from the pressurized exhaust gas source to the at least one fuel valve and gaseous fuel from the supply source of pressurized gaseous fuel to the at least one fuel valve. It includes supply lines for supplying.

According to a seventh possible embodiment of the first aspect, the engine comprises a control unit configured to control the amount of exhaust gas injected simultaneously with the gaseous fuel.

According to an eighth possible embodiment of the first aspect, the engine comprises a plurality of fuel valves, which are at least one or more circumferentially distributed around the cylinder liner.

According to a ninth possible embodiment of the first aspect, at least one fuel valve is provided with at least one injection nozzle.

According to a tenth possible embodiment of the first aspect, at least one fuel valve is provided with a first inlet port connected to a source of pressurized gaseous fuel and a second inlet port connected to an exhaust gas source.

According to an eleventh possible embodiment of the first aspect, the at least one fuel valve comprises a device for mixing gaseous fuel with exhaust gas inside the fuel valve.

According to a twelfth possible embodiment of the first aspect, the simultaneous injection of both gaseous fuel and exhaust gas is preferably initiated during the stroke of the piston towards the cylinder cover after the piston has passed through the scavenging port, and even more preferably the exhaust gas It is carried out at or just before the time the valve is closed.

According to a thirteenth possible embodiment of the first aspect, an ignition system is provided for initiating ignition, preferably at or near the TDC.

According to a fourteenth possible embodiment of the first aspect, the engine is configured to simultaneously inject both gaseous fuel and exhaust gas during a stroke of the piston toward the cylinder cover.

According to a second aspect, there is provided a method of reducing knocking by improving mixing of gaseous fuel and scavenging air in a combustion chamber of a large two-stroke turbocharged single-flow scavenging internal combustion engine, wherein the internal combustion engine is divided into a cylinder liner, a piston, and a cylinder cover. A combustion chamber, a scavenging port disposed on the cylinder liner, an exhaust valve disposed on the cylinder cover, and at least one fuel valve disposed on the cylinder liner to inject gaseous fuel and exhaust gas into the combustion chamber, the method comprising: pressurized gaseous fuel and Supplying pressurized exhaust gas to the fuel valve and simultaneously injecting pressurized gaseous fuel and pressurized exhaust gas into the combustion chamber through the fuel valve to increase the momentum of the substance injected into the combustion chamber during the stroke toward the cylinder cover of the piston do.

According to the first embodiment of the second aspect, the exhaust gas is injected only when the engine load is high, preferably only when the engine load exceeds 60% of the maximum continuous rating of the engine, and even more preferably the engine load is maximum continuous. It is sprayed only when it exceeds 70% of the rating.

These and other aspects will become apparent with the embodiment(s) described below.

In the following detailed part of the present invention, aspects, embodiments, and implementations will be described in more detail with reference to exemplary embodiments shown in the drawings in the drawings.
1 is a front view of a large two-stroke diesel engine according to an exemplary embodiment of the present invention,
Figure 2 is a side view of the large two-stroke engine of Figure 1,
Figure 3 is a schematic diagram of a large two-stroke engine according to Figure 1,
4 is a cross-sectional view of a cylinder frame and cylinder liner according to an exemplary embodiment including a cylinder cover, an exhaust valve mounted to the cylinder cover, and a piston shown in both TDC and BDC,
5 is a partial cross-sectional view of the cylinder liner of FIG. 4,
FIG. 6 is a cross-sectional view of the cylinder liner of FIG. 5 along lines VI-VI' and including a fuel valve arrangement according to an embodiment in which gaseous fuel and injected exhaust gas are delivered to the combustion chamber through one and the same fuel valve;
7 is a setting for a fuel supply and fuel valve apparatus according to an embodiment in which gaseous fuel and injected exhaust gas are mixed before being delivered to the fuel valve,
8 is a setting for a fuel supply and fuel valve apparatus according to an embodiment in which gaseous fuel and injected exhaust gas are mixed inside the fuel valve,
9 is a schematic diagram showing a gas exchange and fuel injection cycle.

In the detailed description below, an internal combustion engine will be described with reference to a large two-stroke low speed turbocharged crosshead internal combustion engine in an exemplary embodiment. 1, 2 and 3 show a large low speed turbocharged two-stroke compression ignition engine equipped with a crankshaft 8 and a crosshead 9. 3 shows a schematic representation of a large low speed turbocharged two-stroke diesel engine with intake and exhaust systems. In this exemplary embodiment, the engine includes four cylinders in a row. Large low-speed turbocharged two-stroke diesel engines generally include 4 to 14 cylinders in a row supported by the engine frame 11. The engine can be used, for example, as a main engine of a ship or a stationary engine for operating a generator of a power plant. The total power of the engine may range from 1,000 to 110,000 kW, for example.

The engine is in this exemplary embodiment a two-stroke single-flow engine having a scavenging port 18 in the lower region of the cylinder liner 1 and a central exhaust valve 4 at the top of the cylinder liner 1. The scavenging air passes from the scavenging receiver 2 through the scavenging port 18 of the individual cylinder 1. The gaseous fuel and the injected air and/or exhaust gas are injected from the fuel injection valve 30 of the cylinder 1, and the piston 10 of the cylinder compresses and compresses the gaseous fuel, the injected exhaust gas and the desired charge. The ignition occurs at or near the TDC, and the ignition is triggered by injection of pilot oil (or other suitable ignition liquid), for example from the pilot oil fuel valve 33, whereby combustion follows and exhaust gas is produced. Other types of ignition systems, such as laser ignition or glow plugs, can also be used to initiate ignition.

When the exhaust valve 4 is opened, the exhaust gas flows into the exhaust gas receiver 3 through the exhaust duct connected to the cylinder 1, and continues to the turbine 6 of the turbocharger 5 through the first exhaust conduit 19. ), the exhaust gas from the turbine passes through the second exhaust conduit and flows to the atmosphere through the outlet 21 via the economizer 20. The turbine 6 drives a compressor 7 through which fresh air is supplied through an intake port 12 through a shaft. The compressor 7 delivers pressurized scavenging to the scavenging conduit 13 leading to the scavenging receiver 2. The scavenging air in the conduit 13 passes through the intercooler 14 for desired cooling.

If the compressor 7 of the turbocharger 5 does not deliver sufficient pressure to the scavenging receiver 2, i.e. in the low or partial load condition of the engine, the cooled scavenging air is sent to the electric motor 17 to pressurize the scavenging flow. It passes through the auxiliary blower 16 driven by. At higher engine loads, the turbocharger compressor 7 delivers a sufficiently compressed scavenging air, and then the auxiliary blower 16 is bypassed via a non-return valve 15.

9 is a graph showing the opening and closing periods of the scavenging port 18, the exhaust valve 4 and the fuel valve 30, respectively, as a function of the crank angle. This graph shows that the opportunity to inject gaseous fuel is very short, allowing a very short time for the gaseous fuel to mix with the scavenging air in the combustion chamber. The gaseous fuel and the injected exhaust gas are injected at such a very short opportunity.

In order to obtain a relatively large mass injected at a relatively high speed to obtain a large momentum of the injected exhaust gas, the amount of the injected exhaust gas is significant, and the pressure of the injected exhaust gas is high.

The momentum of the injected exhaust gas is combined with the momentum of the injected gaseous fuel to create a total momentum much greater than that of the gaseous fuel alone.

Although the injected exhaust gas is a reactive material, since it does not add a calorific value, the calorific value of the material injected into the combustion chamber is not different from the calorific value of the fuel injected into the combustion chamber.

The amount of gaseous fuel injected per engine cycle is determined by the engine load. The amount of exhaust gas injected per engine cycle depends on the injection speed and the need to prevent knocking of a particular engine running on a particular type of gaseous fuel, and is determined by simple trial and error.

Preferably, the exhaust gas is injected for each engine cycle. When the engine load is low, the risk of knocking is generally much less. Thus, in one embodiment, the exhaust gas is injected into the combustion chamber only when the engine load is high, for example, when the maximum continuous rating of the engine is 60 to 70% or more.

In one embodiment, the engine is provided with a knock sensor (not shown), and the amount of added exhaust gas is controlled in response to a signal from the knock sensor. That is, when knocking is detected (and after a while if knocking is not detected), the amount (mass) of the exhaust gas injected increases.

The injected exhaust gas is a mixture with the gaseous fuel and is injected simultaneously with the gaseous fuel or separately from the gaseous fuel in one embodiment.

4, 5 and 6 show a cylinder liner generally designated as 1 for a large two stroke crosshead engine. Depending on the engine size, the cylinder liner 1 can be manufactured in different sizes with a cylinder bore generally ranging from 250 mm to 1000 mm and a corresponding general length ranging from 1000 mm to 4500 mm.

In FIG. 4, the airtight interface between the cylinder liner 1 mounted on the cylinder frame 23 and the cylinder cover 22 disposed on the upper end of the cylinder liner 1 is shown. In Fig. 4, although it is clear that the two positions of the bottom dead center and the top dead center do not occur at the same time and are separated by 180 degree rotation of the crankshaft, the piston 10 is both at the bottom dead center (BDC) and the top dead center (TDC). Schematically shown by the dotted line. The cylinder liner (1) is provided with a cylinder lubrication hole (25) and a cylinder lubrication line (24) for supplying cylinder lubricant when the piston (10) passes through the lubrication line (24), and the next piston ring (not shown). The silver cylinder lubricant is distributed over the working surface of the cylinder liner (1).

In the illustrated embodiment, the thinnest part of the wall 29 is at the bottom of the cylinder liner 1. That is, it is in the lower part of the scavenging port 18. The thickest part of the wall 29 of the cylinder liner 1 is at the top of the axial range of the cylinder liner 1. The sharp transition of the thickness of the cylinder liner 1 in the vicinity of the center of the axial range of the cylinder liner 1 serves as a shoulder that allows the cylinder to rest on the cylinder frame 23. The cylinder cover 22 is pressed with a large force applied by a tensioning bolt on the upper surface of the cylinder liner 1.

The pilot oil valve 33 (generally two or more per cylinder) is mounted on the cylinder cover 22 and connected to a pilot oil supply source (not shown). In the embodiment, the injection timing of the pilot oil is controlled by an electronic control device (not shown).

The fuel valve 30 is mounted on the cylinder liner 1 and is substantially flush with the inner surface of the cylinder liner 1 and is substantially the same as the rear end of the fuel valve 30 proportional from the outer wall of the cylinder liner 1 It is on the plane. In general, three or four fuel valves 30 are provided for each cylinder and distributed equally around the cylinder. The fuel valve 30 is arranged in the middle of the length of the cylinder liner 1 in the embodiment.

5 and 6 show the cylinder liner 1 and the fuel valve 30 in more detail. In this embodiment, the cylinder liner 1 is provided with four fuel valves 30. Although the fuel valve 30 is shown radially in FIG. 6, it can be seen that the fuel valve 30 may be disposed at different angles relative to the cylinder liner 1.

The fuel valve 30 is connected to a common (mixed) source of gaseous fuel and injected exhaust gas in one embodiment. 7 shows a fuel valve 30 connected to both a pressurized gaseous fuel source 40 and a pressurized injection exhaust gas source 44 via a single supply line 42. A valve (not shown) is provided to ensure a desired ratio between the gaseous fuel delivered to the fuel valve 30 and the injected exhaust gas. Common conduit 32 conveys the mixture to the nozzle 39. The mixture is injected into the combustion chamber from the hole of the nozzle 39. The fuel valve 30 is provided with means for injecting the mixture into the combustion chamber over time (eg, under control of an electronic control device).

In the modified embodiment of FIG. 7, the gaseous fuel and the injected exhaust gas are not mixed, but instead are sequentially supplied to the fuel valve 30, so that the gaseous fuel is injected first, or the injected exhaust gas is sequentially injected first. .

In another embodiment of FIG. 8, the pressurized gaseous fuel supply 40 is connected to a dedicated port of the fuel valve 30 by a dedicated supply line 41. A dedicated conduit 31 guides the gaseous fuel to a mixing point 33 inside the fuel valve 30. The exhaust gas supply source 44 is connected to a dedicated port of the fuel valve 30 by a dedicated supply line 45. A dedicated conduit 35 guides the exhaust gas to a mixing point 33 inside the fuel valve 30. At the mixing point 33, the gaseous fuel and exhaust gases are mixed, and from the mixing point 33 the mixture is conveyed by a common conduit 32 to the nozzle 39. The nozzle 39 is provided with a nozzle hole through which the mixture is injected into the combustion chamber. The fuel valve 30 is provided with means for injecting the mixture into the combustion chamber over time (eg, under control of an electronic control device).

delete

Various aspects and embodiments have been described together with various embodiments of the present specification. However, other modifications to the disclosed embodiments can be understood and executed by those skilled in the art in carrying out the claimed subject matter from the study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" does not exclude a plurality. A single processor or other unit may perform the functions of several items recited in the claims. The mere fact that certain options are cited in different dependent claims does not indicate that combinations of those used as options cannot be used to advantage.

Reference signs used in the claims should not be construed as limiting the scope.

4: exhaust valve
18: scavenging port
30, 31: fuel valve
40: pressurized gas fuel supply source
44: pressurized air and/or exhaust gas source

Claims (21)

In a large two-stroke turbocharged single-flow scavenging internal combustion engine operating on gaseous fuel,
A combustion chamber divided into a cylinder liner (1), a piston (10) and a cylinder cover (22);
A scavenging port 18 disposed in the cylinder liner 1;
At least one exhaust valve (4) disposed on the cylinder cover (22);
At least one fuel valve (30, 31) disposed on the cylinder liner (1) for injecting gaseous fuel into the combustion chamber; And
A pressurized gas fuel supply source 40 for the fuel valves 30 and 31 disposed on the cylinder liner 1 and a pressurized exhaust gas supply source 44; All inclusive,
The internal combustion engine supplies both gaseous fuel and exhaust gas through at least one of the fuel valves (30, 31) to increase the momentum of the material injected by the at least one fuel valve (30, 31) into the combustion chamber. A large two-stroke turbocharged single-flow scavenging internal combustion engine, characterized in that it is configured to simultaneously inject into the combustion chamber. The method of claim 1,
A large two-stroke turbocharged single-flow scavenging internal combustion engine, characterized in that the gaseous fuel and the exhaust gas are simultaneously injected into the combustion chamber from at least one fuel valve (30) as a mixture. The method of claim 2,
The gaseous fuel and the exhaust gas are mixed within at least one of the fuel valves (30). A large two-stroke turbocharged single-flow scavenging type internal combustion engine. The method of claim 2,
The gaseous fuel and the exhaust gas are mixed upstream of the at least one fuel valve (30). A large two-stroke turbocharged single-flow scavenging internal combustion engine. The method of claim 1,
A large two-stroke turbocharged single-flow scavenging internal combustion engine comprising a common supply line (42) for supplying the exhaust gas and the gaseous fuel to at least one of the fuel valves (30). The method of claim 1,
The gaseous fuel and the exhaust gas are simultaneously injected from a nozzle hole in a nozzle of at least one of the fuel valves (30). A large two-stroke turbocharged single-flow scavenging internal combustion engine. The method of claim 1,
Separate supply lines 41 and 45 supplying the exhaust gas from the pressurized exhaust gas supply source 44 to at least one of the fuel valves 30 and 31 and the gaseous fuel from the pressurized gas fuel supply source 40 at least A large two-stroke turbocharged single-flow scavenging internal combustion engine, characterized in that it comprises a supply line for supplying one of the fuel valves (30, 31). The method of claim 1,
A large two-stroke turbocharged single-flow scavenging internal combustion engine, comprising: a control unit configured to control the amount of the exhaust gas injected simultaneously with the gaseous fuel. The method of claim 1,
A large two-stroke turbocharged single-flow scavenging internal combustion engine, characterized in that it comprises at least one of a plurality of the fuel valves (30, 31) distributed in a circumferential direction around the cylinder liner (1). The method of claim 1,
A large two-stroke turbocharged single-flow scavenging internal combustion engine, characterized in that at least one of the fuel valves (30, 31) is provided with one or more injection nozzles (39). The method of claim 10,
A large two-stroke turbo, characterized in that at least one of the fuel valves 30 is provided with a first inlet port connected to the pressurized gas fuel supply source 40 and a second inlet port connected to the pressurized exhaust gas supply source 44 Charged single-flow scavenging internal combustion engine. The method of claim 11,
A large two-stroke turbocharged single-flow scavenging internal combustion engine, characterized in that at least one fuel valve (30) comprises a device (33) for mixing the gaseous fuel with the exhaust gas inside the fuel valve (30). The method of claim 1,
The simultaneous injection of the gaseous fuel and the exhaust gas is performed during a stroke of the piston 10 toward the cylinder cover 22, after the piston 20 passes through the scavenging port 18, or the exhaust valve 4 A large two-stroke turbocharged single-flow scavenging internal combustion engine, characterized in that starting immediately before the closing time. The method of claim 1,
A large two-stroke turbocharged single-flow scavenging internal combustion engine, characterized in that there is provided an ignition system to initiate ignition. The method of claim 1,
The internal combustion engine is a large two-stroke turbocharged single-flow scavenging type internal combustion engine, characterized in that a knock sensor is provided and the amount of the added exhaust gas is controlled in response to a signal received from the knock sensor. The method of claim 15,
A large two-stroke turbocharged single-flow scavenging internal combustion engine, characterized in that, when knocking is detected by the knock sensor, the mass of the exhaust gas is increased. The method of claim 16,
A large two-stroke turbocharged single-flow scavenging internal combustion engine, characterized in that, if knocking is not detected by the knock sensor at a predetermined time or during a predetermined engine rotation speed, the mass of the injected exhaust gas is reduced. In a method of reducing knocking by improving mixing of gaseous fuel and scavenging air in a combustion chamber of a large two-stroke turbocharged single-flow scavenging internal combustion engine operating on gaseous fuel, the internal combustion engine comprises:
A combustion chamber divided into a cylinder liner (1), a piston (10) and a cylinder cover (22);
A scavenging port 18 disposed on the cylinder liner 1;
An exhaust valve disposed on the cylinder cover 22; And
And at least one fuel valve (30, 31) disposed on the cylinder liner (1) to inject gaseous fuel and exhaust gas into the combustion chamber,
The method comprises the steps of supplying pressurized gaseous fuel and pressurized exhaust gas to the fuel valves (30, 31) disposed on the cylinder liner (1) and the piston (10) to increase the momentum of the material injected into the combustion chamber. A large two-stroke turbocharging single flow comprising the step of simultaneously injecting the pressurized gaseous fuel and the pressurized exhaust gas into the combustion chamber through the fuel valves 30 and 31 while heading to the cylinder cover 22 A method of reducing knocking by improving the mixing of gaseous fuel and scavenging air in the combustion chamber of a scavenging internal combustion engine. The method of claim 18,
A method of reducing knocking by improving mixing of gaseous fuel and scavenging in a combustion chamber of a large two-stroke turbocharged single-flow scavenging internal combustion engine, wherein the exhaust gas is injected only when the engine load is high. The method of claim 18,
A method of reducing knocking by improving the mixing of gaseous fuel and scavenging in the combustion chamber of a large two-stroke turbocharged single-flow scavenging internal combustion engine, characterized in that the exhaust gas is injected only when the engine load exceeds 60% of the maximum continuous rating of the engine. . The method of claim 18,
The exhaust gas is injected only when the engine load exceeds 70% of the maximum continuous rating of the engine.The method of reducing knocking by improving the mixing of gaseous fuel and scavenging in the combustion chamber of a large two-stroke turbocharged single-flow scavenging internal combustion engine. .

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