Gas engine air / gas mixing device

Abstract

The application discloses a gas engine air / gas mixing device, which comprises an air intake manifold connected with a cylinder cover and forming an air intake passage in front of an air intake valve; a gas injection valve and a gas branch pipe, one end of the gas branch pipe being connected with the gas injection valve and the other end extending into the air intake manifold; and a swirl member arranged in the air intake passage and connected with the gas branch pipe, wherein high-pressure gas sprayed by the gas injection valve is guided into the swirl member through the gas branch pipe and forms a rotating mixed gas flow. The air intake passage is provided with the swirl member, and the spraying energy in the high-pressure gas spraying process can make the gas rotate, drive the air and the mixed gas to rotate and keep entering the cylinder, so that the uniformity of the air / gas mixing is improved, the rotating mixed gas flow entering the cylinder can make the upper, middle and lower layers of gas mix rapidly, and thus better combustion effect is obtained in the combustion stroke.

Description

[0001] The application is a divisional application of the patent application No. CN201811399774.0, with the application date of November 22, 2018, and the invention name of "Gas engine air / gas mixing device". TECHNICAL FIELD

[0002] The application relates to the technical field of engine gas mixing devices, in particular to a device for mixing gas and air used on a gas engine. BACKGROUND

[0003] There are two common gas supply modes for gas engines: one is a single-point premixing mode in which gas is supplied before the air intake manifold, and the other is a multi-point injection mode in which gas is injected in the air passage before the valve. For the multi-point injection mode, one injection valve is arranged before the valve of each cylinder of the engine, and the injection starts after the air intake valve is opened and the scavenging is completed, and the injection stops before the air intake valve is closed. Compared with the single-point premixing mode, the performance indicators of the engine are greatly improved. It has become the consensus of the industry to replace the single-point premixing mode with the advanced multi-point injection mode.

[0004] However, in the multi-point injection mode, the air passage before the air intake valve is relatively short, and the gas injection time is short, so it is difficult to ensure the uniformity of the mixture of gas and air, and the advantages of the multi-point injection mode cannot be fully utilized, which is one of the factors restricting the promotion of the multi-point injection mode.

[0005] As shown in Figure 9 and Figure 10 , it is a common implementation case of the multi-point injection mode. The gas is injected into the air passage 105 before the air intake valve 101 through the gas injection valve 102 and the gas branch pipe 103, mixed with the air, and then enters the cylinder through the air intake valve 101. The phase relationship between the gas and the opening of the valve is shown in Figure 11 , wherein T is the opening phase of the air intake valve, which is basically fixed and unchanged, t is the injection time of the gas injection valve 102, t < T, t changes with the size of the engine load, and especially when the engine load is small, t << T. When the gas injection valve 102 is closed, pure air enters the cylinder through the air intake valve 101, and when the gas injection valve 102 is opened, air / gas mixture enters the cylinder. At the end of the intake stroke, the upper, middle and lower layers in the cylinder present the state of air, mixture and air, which makes the combustion effect worse and affects the performance of the engine.

[0006] The Chinese invention patent CN104454221B discloses an air intake device of an engine, the geometry of the air intake passage is improved, thereby enhancing the air intake vortex and ensuring the filling efficiency of the air intake, but it is applied to a diesel engine, the power of the air intake vortex comes from the air itself (not the fuel gas), the fuel gas engine can be used for reference and obtain certain effect, but still cannot completely meet the mixing requirements of the fuel gas / air.

[0007] The Chinese utility model patent CN 204646460 U discloses a gas mixer for a gas engine, a rotatable displacement body is additionally arranged in the air intake passage, the air-fuel ratio can be changed by rotating the displacement body, thereby being beneficial to the normal operation of the gas fuel with different heat values in the engine.

[0008] The above patent documents do not solve the technical problem that the upper, middle and lower layers in the cylinder present the state of air, mixed gas and air at the end of the air intake stroke of the gas engine, the combustion effect is poor, and the engine performance is affected. SUMMARY

[0009] In view of the above problems of the prior art, the present application provides a gas engine air / fuel gas mixing device to solve the technical problem that the upper, middle and lower layers in the cylinder present the state of air, mixed gas and air at the end of the air intake stroke of the gas engine, the combustion effect is poor, and the engine performance is affected.

[0010] To solve the above technical problems, the present application has the following technical solutions:

[0011] A gas engine air / fuel gas mixing device, comprising:

[0012] An air intake manifold connected with a cylinder head and forming an air intake passage in front of an air intake valve;

[0013] A fuel gas injection valve and a fuel gas branch pipe, one end of the fuel gas branch pipe is connected with the fuel gas injection valve, and the other end extends into the air intake manifold; a rotational flow member is arranged in the air intake passage, the rotational flow member is connected with the fuel gas branch pipe, high-pressure fuel gas injected by the fuel gas injection valve is guided into the rotational flow member through the fuel gas branch pipe and forms a rotational mixed gas flow; the rotational flow member is a cylindrical rotational flow member arranged in the air intake passage of the air intake manifold, the cylindrical rotational flow member is arranged in the same direction as the air intake manifold, tangential air inlet holes are formed in the pipe wall of the cylindrical rotational flow member, and the open end of the fuel gas branch pipe is fixed to the tangential air inlet holes of the cylindrical rotational flow member.

[0014] After the above technical solutions are adopted, the technical effects of the present application are:

[0015] The air intake passage of the present application is provided with a swirl member, by means of which the injection energy in the high-pressure gas injection process can make the gas rotate, drive the air and the mixed gas to rotate and keep entering the cylinder, improve the uniformity of the air / gas mixture, and the rotating mixed gas flow entering the cylinder can make the upper, middle and lower layers of gas mix rapidly, thereby obtaining better combustion effect in the combustion stroke. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural sectional view of the air / gas mixing device of the gas engine according to the present application, embodiment 1;

[0017] Figure 2 is a sectional view of A-A in Figure 1

[0018] Figure 3 is a structural sectional view of the air / gas mixing device of the gas engine according to the present application, embodiment 2;

[0019] Figure 4 is a sectional view of B-B in Figure 3

[0020] Figure 5 is a structural sectional view of the air / gas mixing device of the gas engine according to the present application, embodiment 3;

[0021] Figure 6 is a sectional view of C-C in Figure 5

[0022] Figure 7 is a structural sectional view of the air / gas mixing device of the gas engine according to the present application, embodiment 4;

[0023] Figure 8 is a sectional view of D-D in Figure 7

[0024] Figure 9 is a structural schematic view of a known technology;

[0025] Figure 10 is a sectional view of G-G in Figure 9

[0026] Figure 11 is a graph showing the relationship between the gas injection amount and the valve opening phase in the multi-point sequential injection gas injection of the known technology shown in Figure 9

[0027] ​​​​​​In the figure, 100 - cylinder head, 101 - intake valve, 102 - gas injection valve, 103 - gas branch pipe, 103A - gas branch pipe, 103B - gas branch pipe, 103C - gas branch pipe, 103D - gas branch pipe, 104 - intake manifold, 105 - intake port, 106A - swirler, 106B - swirler, 106C - swirler, 106D - swirler, 107 - gas outlet hole, 108 - gas outlet hole, 109 - gas outlet hole, 200 - rotating mixed gas flow. DETAILED DESCRIPTION

[0028] The application is further illustrated below in conjunction with the accompanying drawings and examples.

[0029] Example 1

[0030] As shown in Figure 1 and Figure 2 A gas engine air / gas mixing device, the intake manifold 104 is connected with the cylinder head 100 and forms the intake port 105 in front of the intake valve 101.

[0031] One end of the gas branch pipe 103A is connected with the gas injection valve 102, and the other end extends into the intake manifold 104. The intake port 105 of the intake manifold 104 is provided with a swirler 106A, the swirler 106A is connected with the gas branch pipe 103A, and the high-pressure gas sprayed by the gas injection valve 102 is introduced into the swirler 106A through the gas branch pipe 103A to form a rotating mixed gas flow 200.

[0032] The swirler 106A is a cylindrical swirler, which is arranged in the same direction as the intake manifold 104. Tangential gas inlet holes are formed in the wall of the cylindrical swirler, and the open end of the gas branch pipe 103A is fixed to the tangential gas inlet holes of the cylindrical swirler.

[0033] Example 2

[0034] As shown in Figure 3 and Figure 4 A gas engine air / gas mixing device, the structure of which is basically the same as that of Example 1. The swirler 106B is also a cylindrical swirler, which is arranged in the intake port 105 of the intake manifold 104. The cylindrical swirler 106B is arranged in the same direction as the intake manifold 104. The difference is that the wall of the cylindrical swirler 106B is provided with radial gas inlet holes, the gas branch pipe 103B extends into the radial gas inlet holes and is fixedly connected with the cylindrical swirler 106B, the opening at the end of the gas branch pipe 103B is closed, and a plurality of gas outlet holes (107, 108) are formed in the wall of the gas branch pipe 103B. The gas sprayed from the gas outlet holes (107, 108) flows along the tangential direction of the inner wall of the cylindrical swirler 106B.

[0035] Example 3

[0036] As Figure 5 and Figure 6 As shown in

[0037] Embodiment 4

[0038] As Figure 7 and Figure 8 As shown in

[0039] In the present application, the intake manifold can be round or square, and is good in adaptability.

[0040] In the present application, when the swirl member is an open circular ring-shaped swirl member, the intake valve is coaxially arranged, and the rotating mixed gas flow 200 does not need to bend when entering the cylinder, so the mixing effect is better.

[0041] The present application is not limited to the above embodiments, and all kinds of improvements based on the concept, principle, structure and method of the present application will fall within the scope of the present application.

Claims

1. A gas engine air / gas mixing device, comprising: an intake manifold connected with a cylinder head and forming an intake passage in front of an intake valve; a gas injection valve and a gas branch pipe connected with the gas injection valve at one end and extending into the intake manifold at the other end; characterized in that: a swirler is arranged in the intake passage, the swirler is connected with the gas branch pipe, and high-pressure gas injected by the gas injection valve is guided into the swirler through the gas branch pipe to form a rotating mixed gas flow; and the swirler is a cylindrical swirler arranged in the intake passage of the intake manifold, the cylindrical swirler is arranged in the same direction as the intake manifold, a tangential intake hole is formed in the wall of the cylindrical swirler, and the open end of the gas branch pipe is fixed to the tangential intake hole of the cylindrical swirler.

2. The gas engine air / gas mixing device according to claim 1, characterized in that: the gas injection valve is arranged in the intake passage of the intake manifold, the gas injection valve is connected with the gas branch pipe, and the gas injection valve is arranged in the same direction as the intake manifold.

3. The gas engine air / gas mixing device according to claim 1, characterized in that: the gas injection valve is arranged in the intake passage of the intake manifold, the gas injection valve is connected with the gas branch pipe, and the gas injection valve is arranged in the same direction as the intake manifold.

4. The gas engine air / gas mixing device according to claim 1, characterized in that: the gas injection valve is arranged in the intake passage of the intake manifold, the gas injection valve is connected with the gas branch pipe, and the gas injection valve is arranged in the same direction as the intake manifold.

5. The gas engine air / gas mixing device according to claim 1, characterized in that: the gas injection valve is arranged in the intake passage of the intake manifold, the gas injection valve is connected with the gas branch pipe, and the gas injection valve is arranged in the same direction as the intake manifold.

6. The gas engine air / gas mixing device according to claim 1, characterized in that: the gas injection valve is arranged in the intake passage of the intake manifold, the gas injection valve is connected with the gas branch pipe, and the gas injection valve is arranged in the same direction as the intake manifold.

7. The gas engine air / gas mixing device according to claim 1,

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