Pipeline for improving gas inlet uniformity of natural gas engine

Abstract

The utility model discloses a pipeline for improving gas inlet uniformity of a natural gas engine, which relates to the technical field of gas inlet pipelines of engines, and comprises a mixer and a gas inlet pipe, the gas inlet pipe is connected with the mixer through a gas inlet elbow, and mixed gas is guided into the engine; wherein air enters the two-section accelerating tube along the front end of the fluid accelerating cover; and the fuel gas and the waste gas after combustion enter the adsorption chamber. According to the pipeline for improving the gas inlet uniformity of the natural gas engine, due to the fact that the mixer designed in a Venturi tube mode is adopted as a gas mixing structure, air, fuel gas and waste gas generated after combustion are fully mixed, and the problem that when an existing engine gas inlet pipeline is used, the gas inlet uniformity of the engine is improved is effectively solved. The technical problem that the proportion of waste gas of each cylinder participating in combustion again cannot be effectively controlled is solved, the purpose of fully mixing gas is achieved, the gas inlet uniformity of each cylinder is improved, engine combustion is improved, and heat efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of engine intake pipelines, in particular to a pipeline for improving intake uniformity of a natural gas engine. Background Art

[0002] Traditional intake manifolds have a single function, generally serving only as a transitional connection between the engine and the intake port. Typical intake mixing devices are external, requiring consideration of engine assembly and sealing. These devices are complex, expensive, and cumbersome to install and use.

[0003] At present, the Chinese patent with the existing patent application number "CN201910883738.X" discloses an intake pipe assembly and its natural gas engine, including: a pipe body, the pipe body is provided with a pipe joint, a bend pipe and a straight pipe, one end of the pipe joint is connected to one end of the bend pipe, and the other end of the bend pipe is connected to one end of the straight pipe; the straight pipe is also provided with a mixer and a throttle valve connected to the straight pipe, and the mixer is also provided with a natural gas intake pipe, one end of the natural gas intake pipe is connected to and fixedly connected to the mixer; the intake pipe assembly and its natural gas engine provided by the present invention directly integrate the turbulent mixing function into the intake pipe, which not only realizes the function, but also reduces the number of parts and saves overall cost. Through the casting or welding process, the mixing function is more reliable and the risk of leakage is reduced.

[0004] However, during the implementation of the above technical solution, at least the following technical problems were found:

[0005] Current National VI natural gas engine systems primarily utilize stoichiometric combustion and exhaust gas recirculation (EGR) technologies. EGR primarily involves cooling post-combustion exhaust gas through an external EGR line before re-entering the combustion process. The varying proportions of exhaust gas entering each cylinder for re-combustion can affect combustion uniformity, potentially causing engine detonation and misfires, negatively impacting engine efficiency, reliability, and comfort. To address this issue, we propose a pipeline designed to improve intake uniformity in natural gas engines. Utility Model Content

[0006] (1) Technical problems solved

[0007] In view of the shortcomings of the existing technology, the utility model provides a pipeline for improving the intake uniformity of a natural gas engine, solving the technical problem that the existing engine intake pipeline cannot effectively control the proportion of exhaust gas re-combustion in each cylinder when in use.

[0008] (2) Technical solution

[0009] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0010] A pipeline for improving intake uniformity of a natural gas engine, applied to the intake pipeline of a natural gas engine, comprising:

[0011] A mixer for mixing fuel gas, air and combustion exhaust gas;

[0012] An intake pipe is connected to the engine and is connected to the mixer via an intake elbow to introduce the mixed gas into the engine;

[0013] The mixer includes an adsorption chamber, inside which are installed corresponding front and rear fluid acceleration covers and two-stage acceleration tubes, both of which are funnel-shaped. Air enters the two-stage acceleration tube along the front end of the fluid acceleration cover;

[0014] The gas enters the adsorption chamber through the gas pipe connected to the outer wall of the adsorption chamber;

[0015] The exhaust gas after combustion enters the adsorption chamber through the EGR inlet opened on the surface of the adsorption chamber.

[0016] Preferably, the end of the fluid acceleration hood extends into the air inlet of the second-stage acceleration tube, and a gap is reserved between the fluid acceleration hood and the second-stage acceleration tube; the fuel gas and exhaust gas after combustion enter the second-stage acceleration tube from the gap between the fluid acceleration hood and the second-stage acceleration tube.

[0017] Preferably, a plurality of through holes are formed on the outside of the fluid acceleration cover, and the through holes are arranged in a circular row on the fluid acceleration cover;

[0018] Among them, the air entering the adsorption chamber is divided into two parts. One part enters the second-stage acceleration tube along the center of the fluid acceleration cover, and the other part passes through the through hole and enters the interior of the adsorption chamber, and then mixes with the fuel gas and the exhaust gas after combustion and enters the second-stage acceleration tube.

[0019] Preferably, the end of the gas pipe is connected to the outer wall of the adsorption chamber, and the gas pipe and the EGR inlet opened on the outer wall of the adsorption chamber correspond to each other.

[0020] Preferably, a boost pressure sensor is installed inside the adsorption chamber, and the boost pressure sensor is connected to a sensor connector on the outer wall of the adsorption chamber.

[0021] Preferably, the intake bend includes an intake bend 1 and an intake bend 2 that are butted against each other, and a spoiler is installed at one end of the intake bend 2 that is butted against the intake bend 1 to guide the gas flowing through the intake bend to rotate.

[0022] (3) Beneficial effects

[0023] Since a mixer designed in the manner of a Venturi tube is used as a gas mixing structure, air, gas, and post-combustion exhaust gas are fully mixed. At the same time, air is used as the main fluid, and the gas and post-combustion exhaust gas are allowed to enter the adsorption chamber from both sides, thereby fully mixing the gases. The gas mixing ratio can also be adjusted by controlling the amount of gas entering. Therefore, the technical problem of the existing engine intake pipe being unable to effectively control the proportion of exhaust gas re-entering combustion in each cylinder during use is effectively solved, thereby achieving the purpose of fully mixing the gases, thereby improving the uniformity of the intake of each cylinder, improving engine combustion, and enhancing thermal efficiency. Secondly, by providing a through hole in the fluid acceleration cover and communicating with the adsorption chamber, the air entering the adsorption chamber can be divided into two parts. One part enters the second-stage acceleration tube along the fluid acceleration cover, maintaining the function of the Venturi tube itself, and the other part of the air passes through the through hole and impacts the gas and combustion exhaust gas in the adsorption chamber, breaking them up, thereby improving the uniformity of the gas mixing and preventing the gas and combustion exhaust gas from only entering the intake pipe along the inner wall of the intake elbow. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and to implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings.

[0025] Figure 1 This is an overall structural diagram of an embodiment of the utility model;

[0026] Figure 2 This is a structural diagram of the connection between the intake elbow and the intake pipe in an embodiment of the present utility model;

[0027] Figure 3 This is a rear view of the mixer in the embodiment of the present utility model;

[0028] Figure 4 This is a front view of a mixer in an embodiment of the present utility model;

[0029] Figure 5 This is a left side view of the mixer in the embodiment of the present utility model;

[0030] Figure 6 This is a partial structural diagram of a mixer in an embodiment of the present utility model.

[0031] Legend: 11, adsorption chamber; 12, fluid acceleration cover; 13, second-stage acceleration tube; 14, gas pipe; 15, exhaust pipe; 16, EGR inlet; 17, air inlet; 18, sensor connector;

[0032] 21. Intake elbow 1; 22. Intake elbow 2; 23. Spoiler;

[0033] 3. Intake pipe. DETAILED DESCRIPTION

[0034] The embodiment of the present application provides a pipeline for improving the intake uniformity of a natural gas engine, thereby effectively solving the technical problem that the existing engine intake pipeline cannot effectively control the proportion of exhaust gas re-combustion in each cylinder when in use. When the existing engine intake pipeline is in use, a mixer designed in the form of a venturi tube is used as a gas mixing structure to fully mix air, gas and exhaust gas after combustion. At the same time, air is used as the main fluid, and the gas and exhaust gas after combustion enter the adsorption chamber from both sides, so that the gases are fully mixed. The proportion of gas mixing can also be adjusted by controlling the amount of gas entering, thereby achieving the purpose of fully mixing the gases, thereby improving the uniformity of the intake of each cylinder and improving the quality of the engine. Improve engine combustion and enhance thermal efficiency; secondly, by opening a through hole on the fluid acceleration cover, and the through hole is connected to the adsorption chamber, the air entering the adsorption chamber can be divided into two parts. One part enters the second-stage acceleration tube along the fluid acceleration cover to maintain the function of the Venturi tube itself, and the other part of the air passes through the through hole to impact the fuel gas and the burned exhaust gas in the adsorption chamber, breaking them up to improve the uniformity of mixing between the gases and avoid the fuel gas and the burned exhaust gas from only entering the intake pipe along the inner wall of the intake elbow. Moreover, the intake end of the gas pipe and the EGR inlet are both inclined, which can make the fuel gas and the burned exhaust gas entering the adsorption chamber rotate, thereby further improving the mixing effect.

[0035] Embodiment: The technical solution in the embodiment of the present application effectively solves the technical problem that the existing engine intake pipe cannot effectively control the proportion of exhaust gas re-combustion in each cylinder during use. The overall idea is as follows:

[0036] In view of the problems existing in the prior art, the utility model provides a pipeline for improving the uniformity of intake of natural gas engines. The pipeline includes a mixer for mixing gas, air and exhaust gas after combustion, an intake pipe 3 connected to the engine and an intake elbow connected between the two. Figure 1 shown.

[0037] Air enters the fluid acceleration cover 12 from the adsorption chamber 11 through the air inlet 17, as shown in FIG. Figure 6As shown, the fuel gas and the exhaust gas after combustion enter the adsorption chamber 11 for mixing. The funnel-shaped fluid acceleration cover 12 and the two-stage acceleration tube 13 cooperate to form a Venturi tube structure. Air is used as the driving medium and flows through the fluid acceleration cover 12, generating negative pressure, sucking the fuel gas and the exhaust gas after combustion inside the adsorption chamber 11 and causing them to mix in the intake elbow. Since the intake pipe 3 is connected to the engine, the mixed gas is discharged from the exhaust pipe 15 at the end of the adsorption chamber 11 (the intake elbow is connected to the exhaust pipe 15 on the adsorption chamber 11), enters the intake pipe 3 along the intake elbow, and is then transmitted to each cylinder by the intake pipe 3 to improve the uniformity of the intake of each cylinder, improve engine combustion, and enhance thermal efficiency.

[0038] The gas enters the adsorption chamber 11 through the gas pipe 14, and the gas outlet end of the gas pipe 14 is connected to the back of the adsorption chamber 11, as shown in FIG. Figure 3 As shown;

[0039] In contrast, the exhaust gas after combustion enters the adsorption chamber 11 through the EGR inlet 16 opened on the surface of the adsorption chamber 11, and the EGR inlet 16 is located at the front end of the adsorption chamber 11, as shown in FIG. Figure 4 As shown, the gas outlet end of the gas pipe 14 is located on both sides of the adsorption chamber 11. In this way, when the air flows through the fluid acceleration cover 12 and the second-stage acceleration tube 13, the negative pressure generated can simultaneously adsorb the gas and the combustion exhaust gas into the second-stage acceleration tube 13. At the same time, since the gas enters the adsorption chamber 11 in the form of injection, the output of the gas can be adjusted as needed during mixing, thereby controlling the mixing ratio between the air, gas, and combustion exhaust gas during mixing. For example, assuming that the air flow rate is 0.03m 3 / h, under the negative pressure generated by the Venturi tube structure, it can absorb 0.01m per hour 3 If the gas pipe 14 is controlled to input 0.006m3 of gas into the adsorption chamber 11 per hour, 3 The combustion exhaust gas that can be absorbed through the EGR inlet 16 is only 0.004m per hour. 3 Therefore, the ratio of gas in the mixed gas is air: gas: combustion exhaust gas = 0.03:0.006:0.004 = 15:3:2. Therefore, if the gas delivery rate is changed to 0.002m3 per hour, 3 , the combustion waste gas entering the adsorption chamber 11 through the EGR inlet 16 is 0.008m per hour. 3, then air: gas: combustion exhaust gas = 0.03:0.002:0.008 = 15:1:4, so the mixing ratio of air, gas and combustion exhaust gas can be adjusted by changing the amount of gas entering, and the boost pressure sensor installed inside the adsorption chamber 11 monitors the pressure inside the adsorption chamber 11 in real time, and the detected data is transmitted to the outside as an electrical signal through the sensor connector 18 on the outer wall of the adsorption chamber 11 (the boost pressure sensor is connected to the sensor connector 18).

[0040] Secondly, in order to improve the mixing uniformity between the gas, air and post-combustion exhaust gas, the gas outlet of the gas pipe 14 and the EGR inlet 16 are both arranged along the tangential direction of the fluid acceleration hood 12, like a traditional volute. In this way, under the action of negative pressure, the gas and combustion exhaust gas entering the adsorption chamber 11 flow into the gap between the fluid acceleration hood 12 and the adsorption chamber 11. This structure is not a necessary structure and can be freely selected and used as needed.

[0041] The Venturi tube structure is mainly composed of a fluid acceleration cover 12 and a second-stage acceleration tube 13, which are opposite to each other. The end of the fluid acceleration cover 12 extends into the air inlet of the second-stage acceleration tube 13, and a gap is reserved between the fluid acceleration cover 12 and the second-stage acceleration tube 13. Figure 6 As shown, the increase in velocity of the fluid when passing through a narrow pipe causes a pressure drop, thereby generating a negative pressure area, so that the fuel gas and the exhaust gas after combustion enter the second-stage accelerating tube 13 from the gap between the fluid acceleration cover 12 and the second-stage accelerating tube 13, and mix with the air flowing through the inside of the second-stage accelerating tube 13, thereby completing the mixing between the three media.

[0042] During the experiment, we found that although the fuel gas and the exhaust gas after combustion can enter the second-stage acceleration tube 13 under the action of negative pressure, the fuel gas and the exhaust gas after combustion are mainly distributed in the area near the inner wall of the second-stage acceleration tube 13, while the air is distributed in the central area, resulting in poor mixing effect. Therefore, we opened a number of through holes on the outside of the fluid acceleration cover 12, and these through holes are evenly arranged in a circular array on the fluid acceleration cover 12, as shown in FIG. Figure 5 and Figure 6 As shown, the air entering the adsorption chamber 11 can be divided into two parts. One part enters the second-stage acceleration tube 13 along the fluid acceleration cover 12 to maintain the function of the Venturi tube itself, and the other part of the air passes through the through hole to impact the fuel gas and combustion exhaust gas in the adsorption chamber 11, breaking them up to improve the uniformity of mixing between the gases and prevent the fuel gas and combustion exhaust gas from only entering the intake pipe 3 along the inner wall of the intake elbow.

[0043] In order to further improve the gas mixing effect, an "impeller"-shaped spoiler 23 is installed inside the intake bend. In order to facilitate the installation of the spoiler 23, the intake bend is divided into an intake bend 1 21 and an intake bend 22 that are connected to each other. The spoiler 23 is installed at one end of the intake bend 22 close to the intake bend 1 21 to guide the gas flowing through the intake bend to rotate, thereby further mixing the gas.

[0044] In the specific implementation process, air enters the fluid acceleration cover 12 from the adsorption chamber 11 toward one end of the gas pipe 14, as shown in FIG. Figure 6 As shown, a funnel-shaped fluid acceleration hood 12 and a two-stage acceleration tube 13 are used to form a Venturi tube structure. Air is used as the driving medium (i.e., the medium flowing in the fluid acceleration hood 12). Air flows through the fluid acceleration hood 12 to generate negative pressure, sucking the combustion gas and the exhaust gas after combustion inside the adsorption chamber 11 and mixing them in the intake elbow.

[0045] Since a number of through holes are opened on the outside of the fluid acceleration hood 12, and these through holes are evenly arranged in a circular array on the fluid acceleration hood 12, the air entering the adsorption chamber 11 is divided into two parts. One part enters the second-stage acceleration tube 13 along the fluid acceleration hood 12 to maintain the function of the Venturi tube itself (generating negative pressure), and the other part of the air passes through the through holes and impacts the fuel gas and combustion exhaust gas in the adsorption chamber 11, breaking them up to improve the uniformity of mixing between the gases and prevent the fuel gas and combustion exhaust gas from only entering the intake pipe 3 along the inner wall of the intake elbow.

[0046] The spoiler 23 connected between the second intake elbow 22 and the first intake elbow 21 rotates the gas flowing through the intake elbow, thereby further mixing the gas.

[0047] Finally, it should be noted that the above embodiments are merely examples for the purpose of illustrating the present invention and are not intended to limit the embodiments. Those skilled in the art will readily appreciate that other variations or modifications based on the above description are possible. It is not necessary and impossible to provide an exhaustive list of all possible embodiments. However, any obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A pipeline for improving intake uniformity of a natural gas engine, applied to the intake pipeline of a natural gas engine, characterized in that: The pipeline includes: A mixer for mixing fuel gas, air and combustion exhaust gas; An intake pipe (3) is connected to the engine, and the intake pipe (3) is connected to the mixer via an intake elbow to introduce the mixed gas into the engine; The mixer comprises an adsorption chamber (11), inside which are installed corresponding fluid acceleration covers (12) and two-stage acceleration tubes (13) at the front and rear ends, both of which are funnel-shaped. Air enters from the front end of the adsorption chamber (11) and flows through the fluid acceleration cover (12) and the two-stage acceleration tubes (13) in sequence. The gas enters the adsorption chamber (11) through a gas pipe (14) connected to the outer wall of the adsorption chamber (11); The exhaust gas after combustion enters the adsorption chamber (11) through an EGR inlet (16) opened on the surface of the adsorption chamber (11).

2. The pipeline for improving intake uniformity of a natural gas engine according to claim 1, characterized in that: The end of the fluid acceleration cover (12) extends into the air inlet of the second-stage acceleration tube (13), and a gap is reserved between the fluid acceleration cover (12) and the second-stage acceleration tube (13); the fuel gas and the exhaust gas after combustion enter the second-stage acceleration tube (13) through the gap between the fluid acceleration cover (12) and the second-stage acceleration tube (13).

3. The pipeline for improving intake uniformity of a natural gas engine according to claim 2, characterized in that: The fluid acceleration cover (12) is provided with a plurality of through holes on its exterior, and the through holes are arranged in a circular pattern on the fluid acceleration cover (12); The air entering the adsorption chamber (11) is divided into two parts through the through hole outside the fluid acceleration cover (12). One part enters the second-stage acceleration tube (13) along the center of the fluid acceleration cover (12), and the other part passes through the through hole and enters the adsorption chamber (11), mixes with the fuel gas and the combustion exhaust gas, and then enters the second-stage acceleration tube (13).

4. The pipeline for improving intake uniformity of a natural gas engine according to claim 1, characterized in that: The end of the gas pipe (14) is connected to the outer wall of the adsorption chamber (11), and the gas pipe (14) is arranged opposite to the EGR inlet (16) opened on the outer wall of the adsorption chamber (11).

5. The pipeline for improving intake uniformity of a natural gas engine according to claim 1, characterized in that: A boost pressure sensor is installed inside the adsorption chamber (11), and the boost pressure sensor is connected to a sensor connector (18) on the outer wall of the adsorption chamber (11).

6. The pipeline for improving intake uniformity of a natural gas engine according to claim 1, characterized in that: The air intake bend comprises an air intake bend 1 (21) and an air intake bend 2 (22) which are connected to each other, and a spoiler (23) is installed at one end of the air intake bend 2 (22) connected to the air intake bend 1 (21) to guide the gas flowing through the air intake bend to rotate.

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