CN215256451U - Combustion chamber and natural gas engine - Google Patents

Abstract

The utility model provides a combustion chamber and natural gas engine, relate to engine combustion technology field, in order to solve among the correlation technique because whole air current intensity is lower in the combustion chamber and cause the problem of influence to the work thermal efficiency of engine, this combustion chamber includes the cylinder, piston and combustion chamber body, the piston is arranged in the cylinder, the mouth edge department of being close to the cylinder is provided with (air) intake valve and exhaust valve, the top surface of piston is provided with the depressed part, the depressed part forms the combustion chamber body, the axis of the relative cylinder of central line of combustion chamber body squints on the horizontal direction, the combustion chamber body squints towards (air) intake valve one side. The utility model provides a combustion chamber and natural gas engine can improve the work thermal efficiency of engine.

Description

Combustion chamber and natural gas engine

Technical Field

The utility model relates to an engine combustion technology field especially relates to a combustion chamber and natural gas engine.

Background

The natural gas is a clean and convenient fuel, and the existing partial natural gas engine is obtained by directly modifying a diesel engine or a gasoline engine, wherein the core of the development of the natural gas engine is to improve the combustion efficiency and reduce the emission and the oil consumption, the development of the natural gas engine is mainly focused on the development of a combustion system, and the natural gas can be promoted to be more uniformly and intensively combusted in the combustion system by developing the combustion system matched with the physicochemical characteristic of the natural gas, so that the working thermal efficiency of the engine is improved.

In the development of a combustion system, the design of a combustion chamber structure is the core of the development of the combustion system, the structure of the combustion chamber can influence the flow of gas, the flow field distribution in an engine cylinder and the like, in the prior art, a bowl-shaped combustion chamber structure is generally adopted, gas fuel enters the bowl-shaped combustion chamber from an inlet valve, the gas fuel is extruded mutually in the bowl-shaped combustion chamber to form in-cylinder flow, the gas fuel is ignited through a spark plug, and the combusted waste gas is discharged from an exhaust valve.

However, with the bowl-type combustion chamber structure, the overall airflow intensity and turbulence intensity in the combustion chamber before combustion are low, which tends to result in a slow flame propagation speed during combustion and a reduced operating thermal efficiency of the engine.

SUMMERY OF THE UTILITY MODEL

In order to solve at least one problem mentioned in the background art, the utility model provides a combustion chamber and natural gas engine can improve the work thermal efficiency of engine.

In a first aspect, the embodiment of the utility model provides a combustion chamber, including cylinder, piston and combustion chamber body, the piston is located in the cylinder, be close to the mouth edge department of cylinder is provided with (air) intake valve and exhaust valve, the top surface of piston is provided with the depressed part, the depressed part forms the combustion chamber body, the central line of combustion chamber body is relative the axis of cylinder squints on the horizontal direction, the combustion chamber body orientation intake valve one side squints.

The combustion chamber as described above, optionally, the offset distance of the combustion chamber body is between 5-15 mm.

The combustion chamber as described above, optionally, the combustion chamber body includes a combustion chamber upper half and a combustion chamber lower half, the combustion chamber upper half is a cylindrical shell structure, the combustion chamber lower half is provided with a cylindrical structure with a reduced diameter, and the combustion chamber lower half and the combustion chamber upper half are in transition through an arc section.

In the combustion chamber, optionally, the inner wall of the lower half part of the combustion chamber is provided with a boss.

The combustion chamber as described above, optionally, the number of the bosses is plural, and the plural bosses are arranged at intervals on the inner wall of the lower half part of the combustion chamber;

or the boss is an annular boss which is arranged on the inner wall of the lower half part of the combustion chamber in a surrounding mode.

The outer diameter of the upper half part of the combustion chamber is 80-120mm, and the outer diameter of the annular boss is 50-100 mm.

The combustor is characterized in that the depth of the combustor body is 20-40mm, and the depth of the annular boss from the center of the combustor body to the upper half of the combustor is 15-35 mm.

In the combustion chamber, optionally, the annular boss has a ring cross-sectional radius of 2-10 mm.

The combustion chamber as described above, optionally, the cylinder includes a cylinder sleeve and a cylinder cover, the cylinder sleeve is disposed around the outer peripheral wall of the cylinder, the cylinder cover is disposed on the cylinder, and the piston reciprocates in the cylinder.

In a second aspect, the present invention further provides a natural gas engine comprising a combustion chamber as described above.

The embodiment of the utility model provides a combustion chamber and natural gas engine, combustion chamber include cylinder, piston and combustion chamber body, the piston is located in the cylinder, be close to the mouth edge department of cylinder is provided with (air) intake valve and exhaust valve, the top surface of piston is provided with the depressed part, the depressed part forms the combustion chamber body, the central line of combustion chamber body is relative the axis of cylinder squints on the horizontal direction, the combustion chamber body orientation intake valve one side squints.

Through setting up the combustion chamber body and leaning towards intake valve one side, can increase the intake area of the in-process fuel of admitting air and fresh air like this, thereby improve holistic air current intensity and turbulence intensity in the combustion chamber, on the other hand can reduce the loss to the tumble flow that admits air, make the combustion chamber of intake valve side can keep the tumble of high strength, the tumble flows and can last longer time, and influence range is bigger, therefore, the combustion chamber that provides in the application, holistic air current intensity and turbulence intensity are lower in having solved the combustion chamber among the prior art, and flame propagation speed is slower problem when leading to the burning, thereby be favorable to improving the work thermal efficiency of engine.

In addition to the technical problems, technical features constituting technical solutions, and advantageous effects brought by the technical features of the technical solutions described above, other technical problems, technical features included in technical solutions, and advantageous effects brought by the technical features that can be solved by the combustion chamber provided by the embodiments of the present invention will be described in further detail in the detailed description of the embodiments.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of a combustion chamber provided in an embodiment of the present invention;

FIG. 2 is a graph illustrating comparative analysis of gas turbulence in a combustion chamber according to an embodiment of the present invention;

fig. 3 is a graph for comparing and analyzing cylinder pressures in a combustion chamber and a conventional combustion chamber provided by an embodiment of the present invention;

FIG. 4 is a graph of a comparative analysis of heat release rate in a combustion chamber according to an embodiment of the present invention;

FIG. 5a is a simulation of a turbulent gas flow energy field in a combustion chamber according to an embodiment of the present invention;

FIG. 5b is a simulation of a gas turbulence flow energy field in a prior art combustor;

fig. 6a is a simulation diagram of a flame propagation process in a combustion chamber according to an embodiment of the present invention;

fig. 6b is a simulation diagram of the flame propagation process in the conventional combustion chamber.

Description of reference numerals:

100-a combustion chamber;

10-cylinder;

11-cylinder jacket;

12-a cylinder head;

20-a piston;

30-a combustion chamber body;

31-upper combustion chamber half;

32-lower half of the combustion chamber;

321-a boss;

40-an intake valve;

and 50-an exhaust valve.

Detailed Description

The natural gas is a clean and convenient fuel, and the existing partial natural gas engine is obtained by directly modifying a diesel engine or a gasoline engine, wherein the core of the development of the natural gas engine is to improve the combustion efficiency and reduce the emission and the oil consumption, the development of the natural gas engine is mainly focused on the development of a combustion system, and the natural gas can be promoted to be more uniformly and intensively combusted in the combustion system by developing the combustion system matched with the physicochemical characteristic of the natural gas, so that the working thermal efficiency of the engine is improved.

In the development of a combustion system, the design of a combustion chamber structure is the core of the development of the combustion system, the structure of the combustion chamber can influence the flow of gas, the flow field distribution in an engine cylinder and the like, wherein the combustion chamber is a device in which fuel or propellant is combusted to generate high-temperature gas, and is combustion equipment made of high-temperature-resistant alloy materials. The top dead center is the highest point reached by the piston when moving in the cylinder, that is, the position of the piston when the inner volume of the cylinder reaches the minimum.

In the prior art, a bowl-shaped combustion chamber structure is generally adopted, the bowl-shaped combustion chamber structure comprises a cylinder, a piston and the like, an inlet valve and an exhaust valve are arranged at the edge of a port close to the cylinder, the diameter of the inlet valve is required to be larger than that of the exhaust valve under normal conditions, so that the air inlet area and the air inlet amount of the inlet valve can be increased, and meanwhile, the air inlet resistance can be reduced, fuel enters the combustion chamber from the inlet valve, mutually extrudes in the bowl-shaped combustion chamber to form cylinder flow, and is ignited by a spark plug, and combusted waste gas is discharged from the exhaust valve, wherein the central line of the existing combustion chamber is superposed with the central axis of the cylinder, so when the bowl-shaped combustion chamber structure is adopted, the diameters of the inlet valve and the exhaust valve are the same, the air inlet area is easy to be smaller, the squish area in the combustion chamber is insufficient, the squish airflow is weaker, in addition, the diameter ratio of the inlet valve of the combustion chamber is smaller, the turbulence of the intake tumble close to the intake valve is strong, so that the tumble is easy to dissipate too fast, and therefore by adopting the combustion chamber, the overall airflow intensity and turbulence intensity in the combustion chamber before combustion are low, the propagation speed of flame during combustion is slow, and the working thermal efficiency of an engine is reduced.

To the technical problem, the utility model provides a combustion chamber and natural gas engine, combustion chamber include cylinder, piston and combustion chamber body, and the piston is arranged in the cylinder, and the mouth edge department that is close to the cylinder is provided with (air) intake valve and exhaust valve, and the piston top surface is provided with the depressed part, and the depressed part forms the combustion chamber body, and the axis of the relative cylinder of central line of combustion chamber body squints on the horizontal direction, and the combustion chamber body squints towards (air) intake valve one side.

Through setting up the combustion chamber body and leaning towards intake valve one side, can increase the intake area of the in-process fuel of admitting air and fresh air like this, thereby improve holistic air current intensity and turbulence intensity in the combustion chamber, on the other hand can reduce the loss to the tumble flow that admits air, make the combustion chamber of intake valve side can keep the tumble of high strength, the tumble flows and can last longer time, and influence range is bigger, therefore, the combustion chamber that provides in the application, holistic air current intensity and turbulence intensity are lower in having solved the combustion chamber among the prior art, and flame propagation speed is slower problem when leading to the burning, thereby be favorable to improving the work thermal efficiency of engine.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The invention is described below with reference to the accompanying drawings in conjunction with specific embodiments.

Example one

Fig. 1 is the schematic structural diagram of the combustion chamber provided by the embodiment of the utility model, fig. 2 is the utility model provides a gas turbulence kinetic energy contrastive analysis curve graph in combustion chamber and the current combustion chamber, fig. 3 is the utility model discloses cylinder pressure contrastive analysis curve graph in combustion chamber and the current combustion chamber that provides, fig. 4 is the utility model discloses heat release rate contrastive analysis curve graph in combustion chamber and the current combustion chamber that provides, fig. 5a is the simulation picture of gas turbulence flow energy field in the combustion chamber that the embodiment of the utility model provides, fig. 5b is the simulation picture of gas turbulence flow energy field in the current combustion chamber, fig. 6a is the simulation picture of flame propagation process in the combustion chamber that the embodiment provides, fig. 6b is the simulation picture of flame propagation process in the current combustion chamber.

As shown in fig. 1, the present invention provides a combustion chamber 100, the combustion chamber 100 may include a cylinder 10, a piston 20 and a combustion chamber body 30, the piston 20 is located in the cylinder 10, wherein the cylinder 10 is a cylindrical metal part and guides the piston 20 to reciprocate therein, an intake valve 40 and an exhaust valve 50 are provided near a port edge of the cylinder 10, the intake valve 40 sucks external air into the engine and mixes and combusts with fuel in the combustion chamber body 30, the exhaust valve 50 discharges combusted exhaust gas and dissipates heat, it should be noted that, in this embodiment, for the diameter requirements of the intake valve 40 and the exhaust valve 50 and the clearance provided between the intake valve 40 and the exhaust valve 50, the clearance can be set according to the charge amount and the discharge amount of the engine, if the clearance between the intake valve 40 and the exhaust valve 50 is set too small, the power of the engine can be reduced, and even burning of the valve, if the clearance between the intake valve 40 and the exhaust valve 50 is excessively large, it is easy to increase the wear of the parts.

In this embodiment, a concave portion is provided on the top surface of the piston 20, the concave portion forms the combustion chamber body 30, when the piston 20 moves to the top dead center in the cylinder 10, the fuel starts to burn in the combustion chamber 100, it should be explained that the top dead center is the highest point reached when the piston 20 moves in the cylinder 10, that is, the position of the piston 20 when the internal volume of the cylinder 10 reaches the minimum, the piston 20 is at the top dead center when the fuel is burned, and the piston 20 is at the bottom dead center after the fuel is burned. Note that, as shown in fig. 1, a broken line h1 indicates a position of the central axis of the cylinder 10, and a broken line h2 indicates a position of the central axis of the combustion chamber body 30.

In the present embodiment, the combustion chamber body 30 is offset toward the intake valve 40, so that the diameter of the intake valve 40 is larger than the diameter of the exhaust valve 50, which helps to increase the intake area, the fuel is squeezed in the combustion chamber body 30 to form a squish area, so that the squish area is sufficient, the squish gas flow is increased, when the piston 20 runs to the top dead center, the fuel starts to burn in the combustion chamber 100, because the squish area is sufficient, it is beneficial to improve the gas flow strength and turbulence strength in the combustion chamber body 30, and accelerate the combustion speed of the fuel (see fig. 2 in particular), wherein, in fig. 2, the combustion chamber 100 provided in the present application is compared with the gas turbulence kinetic energy in the existing combustion chamber 100 to analyze a graph, in fig. 2, s1 is the gas turbulence kinetic energy graph in the combustion chamber 100 of the present application, s2 is the gas turbulence kinetic energy graph in the existing combustion chamber 100, when the crankshaft rotates to a certain angle, the turbulent kinetic energy of the combustion chamber 100 in the present application is obviously higher than that of the existing combustion chamber 100 before the top dead center, and the turbulent intensity is also higher, it should be noted that the crankshaft is installed inside the cylinder 10, and the crankshaft is provided with a connecting rod, and the crankshaft drives the piston 20 to reciprocate in the cylinder 10 through the connecting rod.

In the present embodiment, as shown in fig. 3, when the crankshaft rotates to a certain angle, the piston 20 moves to the top dead center position, at this time, the squish area in the cylinder 10 is sufficient, the pressure in the cylinder 10 increases rapidly, and the peak phase can be reached in advance, the duration of the fuel in the combustion chamber 100 is shortened, and the isochoric degree of the fuel is improved, where the isochoric degree of the fuel refers to the proportion of the isochoric heating cycle in the cyclic heating to the mixed heating cycle, and the higher the isochoric degree of the fuel, the higher the thermal efficiency of the engine is, where s1 in fig. 3 is the pressure curve of the cylinder 10 in the combustion chamber 100 of the present application, and s2 is the pressure curve of the cylinder 10 in the existing combustion chamber 100.

In this embodiment, as shown in fig. 4, when the crankshaft rotates to a certain angle, the average pressure in the cylinder 10 reaches a peak value, the intensity of the turbulent kinetic energy in the combustion chamber 100 is also improved to a certain extent, so that the flame propagation speed during the combustion of the fuel is increased, thereby shortening the overall combustion time of the fuel in the combustion chamber 100, wherein the flame propagation speed refers to the advancing speed of the flame front along the normal direction of the flame front relative to the unburned combustible mixture, the flame propagation speed determines the moving speed of the flame front in the space for carrying out the combustion process, the value of the air-fuel ratio depends on the nature, pressure, temperature, excess air coefficient, combustible mixture flowing condition, ambient heat dissipation condition and the like of the combustible mixture, in fig. 4, s1 is a graph showing a change in heat release rate in the combustion chamber 100 of the present application, and s2 is a graph showing a change in heat release rate in the conventional combustion chamber 100.

In the present embodiment, as shown in fig. 5a to 6b, fig. 5a to 6b are respectively a comparative analysis simulation diagram of each feature of the combustion chamber 100 and the existing combustion chamber 100 in the present application, wherein, part a in fig. 5a is the gas turbulence energy field in the combustion chamber 100 of the present application, and part B in fig. 5B is the gas turbulence energy field in the combustion chamber 100 of the prior art, it can be seen from the comparison between fig. 5a and fig. 5B that the combustion chamber 100 provided in the present application can maintain high intensity turbulence, the compression area of the gas fuel is concentrated and sufficient, in addition, a part a in fig. 6a is a propagation process diagram of a flame in the combustion chamber 100 of the present application, and a part B in fig. 6B is a propagation process diagram of a flame in the conventional combustion chamber 100, and as can be seen from a comparison between fig. 6a and fig. 6B, the combustion chamber 100 provided in the present application has a large flame propagation area and a more concentrated combustion area.

Therefore, the combustion chamber 100 provided in the present embodiment includes the cylinder 10, the piston 20, and the combustion chamber body 30, the piston 20 is located in the cylinder 10, the intake valve 40 and the exhaust valve 50 are provided near the opening edge of the cylinder 10, the top surface of the piston 20 is provided with a recessed portion, the recessed portion forms the combustion chamber body 30, the center line of the combustion chamber body 30 is offset in the horizontal direction with respect to the center axis of the cylinder 10, and the combustion chamber body 30 is offset toward the intake valve 40 side.

Through setting up combustion chamber body 30 towards intake valve 40 one side skew, can increase the intake area of the in-process fuel of admitting air and fresh air on the one hand like this, thereby whole air current intensity and turbulent intensity in the improvement combustion chamber 100, on the other hand can reduce the loss to the intake tumble, make combustion chamber 100 of intake valve 40 side can keep the tumble of high strength, the tumble flows and can last longer time, and influence range is bigger, therefore, the combustion chamber 100 that provides in the application, whole air current intensity and turbulent intensity are lower in having solved combustion chamber 100 among the prior art, and the slower problem of flame propagation speed when leading to the burning, thereby be favorable to improving the work thermal efficiency of engine.

Further, as shown in fig. 1, the offset distance of the combustion chamber body 30 may be between 5mm and 15mm, wherein the offset distance of the combustion chamber body 30 may be h, and for example, h may be 5mm, h may be 7mm, and h may also be 15mm, which is not specifically limited in this embodiment, as long as the offset distance of the combustion chamber body 30 is between 5mm and 15mm, which all belong to the protection scope of this application.

In the embodiment, the offset distance of the combustion chamber body 30 is set to be 5-15mm, so that on one hand, when the offset distance is too small, the overall airflow intensity and turbulence intensity in the combustion chamber 100 cannot be effectively improved, and on the other hand, when the offset distance is too large, the diameter of the exhaust valve 50 is too small, so that the exhaust gas is not beneficial to being discharged from the exhaust valve 50.

Further, as shown in fig. 1, the combustion chamber body 30 may include an upper combustion chamber half 31 and a lower combustion chamber half 32, the upper combustion chamber half 31 may be a cylindrical shell structure, the lower combustion chamber half 32 is provided with a cylindrical structure with a reduced diameter, the lower combustion chamber half 32 and the upper combustion chamber half 31 are in arc transition, and a throat is provided on the lower combustion chamber half 32, so that the fuel located in the lower combustion chamber half 32 may move upwards during combustion, which is beneficial to eliminating a dead zone in the combustion chamber 100, and can ensure that the fuel is sufficiently combusted in the combustion chamber 100, thereby improving the operating thermal efficiency of the engine. In the present embodiment, the lower combustion chamber half 32 and the upper combustion chamber half 31 are in transition through an arc section, so that a sharp corner on the outer peripheral wall of the combustion chamber 100 can be avoided.

Further, the inner wall of the lower combustion chamber half 32 may be provided with a boss 321, and by providing the boss 321, the tumble flow in the combustion chamber 100 flows through the boss 321 and collides with the boss 321, and the collided tumble flow moves toward the upper combustion chamber half 31, so that the tumble flow in the combustion chamber body 30 is more concentrated and uniform. The size of the boss 321 is not further limited in this embodiment, because the size of the boss 321 can be specifically set according to the combustion chamber 100, and it is within the protection scope of the present application as long as the boss 321 and the tumble flow collide with each other through its own structure.

Further, in a possible implementation manner, the number of the bosses 321 may be multiple, and the multiple bosses 321 are arranged on the inner wall of the lower combustion chamber half 32 at intervals, and in another possible implementation manner, the boss 321 may be an annular boss 321, and the annular boss 321 is arranged on the inner wall of the lower combustion chamber half 32 in a surrounding manner, of course, the shape of the boss 321 includes but is not limited to this, and in this embodiment, the example of specifically setting the boss 321 as the annular boss 321 is described. By providing the annular boss 321, the mutual collision between the tumble flow and the boss 321 can be further improved, and the tumble flow in the combustion chamber body 30 can be more concentrated and uniform.

Further, as shown in fig. 1, the outer diameter of the upper half 31 of the combustion chamber may be between 80 and 120mm, the outer diameter of the annular boss 321 is between 50 and 100mm, wherein, the outer diameter of the upper half 31 of the combustion chamber may be L1, the outer diameter of the annular boss 321 may be L2, exemplarily, L1 may be 80mm, L1 may be 100mm, and L1 may also be 120mm, all belong to the protection range of the present application as long as the outer diameter of the upper half 31 of the combustion chamber is between 80mm and 120mm, similarly, L1 may be 50mm, L1 may be 80mm, and L1 may also be 100mm, all belong to the protection range of the present application as long as the outer diameter of the annular boss 321 is between 50mm and 100mm, by setting the outer diameter of the annular boss 321 to be 50-100mm, the problem that the tumble flow is dispersed when the outer diameter of the annular boss 321 is too large can be avoided.

Further, the depth of the combustion chamber body 30 may be between 20 and 40mm, and the depth of the center of the ring-shaped boss 321 from the upper combustion chamber half 31 may be between 15 and 35mm, wherein the depth of the combustion chamber body 30 may be H1, and the depth of the center of the ring-shaped boss 321 from the upper combustion chamber half 31 may be H2, for example, H1 may be 20mm, H1 may be 30mm, and H1 may also be 40mm, as long as the depth of the combustion chamber body 30 between 20 and 40mm falls within the protection range of the present application, and likewise, H2 may be 15mm, H2 may be 20mm, and H2 may also be 35mm, as long as the depth of the center of the ring-shaped boss 321 from the upper combustion chamber half 31 falls within the protection range of the present application.

Further, the ring section radius of the annular boss 321 may be 2-10mm, for example, the ring section radius may be 2mm, the ring section radius may be 5mm, and the ring section radius may also be 10mm, which is not specifically limited in this embodiment, as long as the ring section radius of the annular boss 321 is 2-10mm, and the protection scope of this application is included.

Further, as shown in fig. 1, the cylinder 10 may include a cylinder liner 11 and a cylinder head 12, the cylinder liner 11 is disposed around the outer circumferential wall of the cylinder 10, the cylinder head 12 covers the cylinder 10, the piston 20 reciprocates in the cylinder 10, fuel starts to be combusted in the combustion chamber 100 when the piston 20 moves to the top dead center in the cylinder 10, and the combustion ends when the piston 20 moves to the bottom dead center.

Example two

On the basis of the first embodiment, the second embodiment provides a natural gas engine, which includes any one of the combustion chambers 100.

The combustion chamber 100 in this embodiment has the same structure as the combustion chamber 100 in the first embodiment, and can bring about the same or similar technical effects, and other technical features are the same as those of the first embodiment or the second embodiment, and can achieve the same technical effects, which are not described herein again.

In the description of the present invention, it is to be understood that the terms "center", "length", "width", "thickness", "top", "bottom", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "inner", "outer", "axial", "circumferential", and the like, which are used to indicate the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of the description, and do not indicate or imply that the position or element referred to must have a particular orientation, be of particular construction and operation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; either directly or indirectly through intervening media, such as through internal communication or through an interaction between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims (10)

1. A combustor, comprising: the piston is positioned in the cylinder, an inlet valve and an exhaust valve are arranged at the position, close to the opening edge of the cylinder, of the piston, a concave part is arranged on the top surface of the piston, the concave part forms the combustion chamber body, the central line of the combustion chamber body is opposite to the central axis of the cylinder and deviates in the horizontal direction, and the combustion chamber body faces to one side of the inlet valve.

2. The combustor of claim 1, wherein the combustor body is offset by a distance of between 5-15 mm.

3. The combustor according to claim 2, wherein the combustor body comprises a combustor upper half and a combustor lower half, the combustor upper half is a cylindrical shell structure, the combustor lower half is provided with a cylindrical structure with a reduced diameter, and the combustor lower half and the combustor upper half are transited through an arc section.

4. A combustion chamber according to claim 3, characterized in that the inner wall of the lower half of the combustion chamber is provided with a boss.

5. The combustor according to claim 4, wherein the boss is a plurality of bosses, and the plurality of bosses are arranged on the inner wall of the lower half part of the combustor at intervals;

or the boss is an annular boss which is arranged on the inner wall of the lower half part of the combustion chamber in a surrounding mode.

6. The combustor of claim 5, wherein the outer diameter of the upper combustor half is between 80-120mm and the outer diameter of the annular boss is between 50-100 mm.

7. The combustor of claim 6, wherein the depth of said combustor body is between 20-40mm and the depth of the annular boss's center-of-circle from the upper combustor half is between 15-35 mm.

8. The combustor of claim 7, wherein the annular boss has a ring cross-sectional radius of between 2-10 mm.

9. The combustion chamber as claimed in any one of claims 1 to 8, wherein the cylinder includes a cylinder liner disposed around an outer peripheral wall of the cylinder and a cylinder head disposed on the cylinder, the piston reciprocating in the cylinder.

10. A natural gas engine comprising a combustion chamber according to any one of claims 1 to 9.

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