Gas mixing device based on shear flow

Abstract

The invention discloses a gas device based on shear flow, which comprises a first gas inlet flange, the first gas inlet flange is connected with a mixer shell, a second gas inlet pipeline is arranged on the mixer shell in a penetrating manner, and the left end of the mixer shell is connected with a first gas inlet pipeline; the right end of the gas I inlet pipeline is connected with a spherical seal head and is provided with slotted holes which are uniformly distributed along the pipe diameter, and the slotted holes are positioned right below the outlet of the gas II pipeline; and a semi-elliptical plate is mounted in the mixer shell and is positioned at one end, far away from the gas I inlet flange, of the gas II inlet pipeline. The gas I tangentially flows at the slotted hole and is subjected to first-stage mixing with the gas II, so that the gas flow close to the pipe wall layer is changed; according to the gas mixing device, the first-stage mixing is realized after the gas passes through the semi-elliptical plate, and the second-stage mixing is realized after the gas passes through the semi-elliptical plate, so that the gas mixing uniformity is improved, the pressure loss of the second gas pipeline is not increased, the second-stage mixing is realized while the gas flow channel is changed, and the mixed gas reaches a complete turbulent flow state.

Description

Technical Field

[0001] The invention belongs to the technical field of gas mixing, and in particular relates to a gas mixing device based on shear flow. Background Art

[0002] Under the background of "dual carbon", China's energy structure is accelerating its transformation towards diversification, cleanliness and low carbonization. Natural gas, as a clean, low-carbon and efficient fossil energy, is the main energy source for building a new energy system. As a "partner energy" of new energy, it plays an important role in the transformation of China's energy system. In order to promote the integrated development of natural gas and new energy, the natural gas hydrogen blending technology was proposed based on the research on the integrated development path of natural gas and new energy such as photovoltaic power generation, wind power, geothermal energy, and hydrogen energy.

[0003] Natural gas hydrogen blending is a technology that blends hydrogen into natural gas at a certain volume ratio to form a hydrogen-natural gas mixed fuel. It combines the characteristics of hydrogen's fast combustion rate and wide ignition limit with the advantages of natural gas's high volume calorific value. Since 2000, research has been carried out on related application technologies such as pipeline hydrogen blending, hydrogen blending storage, and terminal equipment hydrogen blending around the world. Multiple experiments on combustion characteristics have shown that the combustion rate of the mixed gas after hydrogen blending has improved, greatly improving the cycle thermal efficiency.

[0004] The attention paid to hydrogen-blended natural gas is increasing both at home and abroad. However, the physical properties of hydrogen and natural gas are quite different, which may lead to changes in their mixed flow characteristics and the impact on pipelines. Uneven mixing will lead to stratification between the two gases. Due to the flammable and explosive characteristics of hydrogen, low mixing uniformity will affect the use of end users and will cause certain risks in use.

[0005] Therefore, how to more efficiently mix hydrogen and natural gas has become one of the main research directions of hydrogen-blended natural gas mixers. At present, most mixers use vertical cross-mixing flow as the mixing method, but in order to achieve the mixing accuracy, the mixing distance of the mixer designed in this way is mostly long or the mixing length is too long, which is not conducive to equipment layout. Summary of the invention

[0006] In order to solve the above-mentioned problems existing in the prior art, the present invention provides a gas mixing device based on shear flow, which solves the problem of excessive longitudinal length of the natural gas and hydrogen mixing device, effectively shortens the mixing distance under the same mixing accuracy, and provides a new idea for subsequent hydrogen-blended natural gas mixing applications.

[0007] The technical solution adopted by the present invention is:

[0008] A gas mixing device based on shear flow, comprising a gas inlet flange, one side of the gas inlet flange is fixedly connected to a gas inlet pipe, the gas inlet pipe is provided with slots evenly distributed along the pipe diameter, and the end of the gas inlet pipe is fixedly connected to a spherical head;

[0009] The gas mixing device also includes a mixer housing, one end of which is fixedly connected to a conical end cap, and a gas inlet pipe passes through the conical end cap; a gas inlet pipe is passed through the mixer housing, and a slot is arranged just below the outlet of the gas inlet pipe; a semi-elliptical plate is also fixedly installed in the mixer housing, and the semi-elliptical plate is located at one end of the gas inlet pipe away from the gas inlet flange;

[0010] The other end of the mixer housing is fixedly connected with a mixed gas outlet flange, and two supports are further arranged outside the mixer housing.

[0011] Preferably, the gas one inlet pipe is provided with four groups of tangential slots, and when the gas one flows through the slots, shear flow occurs with the gas two, thereby achieving the first-stage mixing of the two gases.

[0012] Preferably, the number of semi-elliptical plates is greater than one group, each group of semi-elliptical plates is a cross-shaped guide structure, and several groups of semi-elliptical plates are connected in sequence to form a guide device with two mutually intersecting gas channels. The mixture of gas one and gas two realizes the second-level mixing of the two gases through the guide device.

[0013] Preferably, the flow guiding device is coaxially arranged with the mixer housing.

[0014] Preferably, the second gas inlet pipe is arranged vertically to the mixer shell.

[0015] Preferably, the inlet of the second gas inlet pipeline is fixedly connected with a second gas inlet flange.

[0016] Preferably, the mixer housing and the semi-elliptical plate are both made of stainless steel.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. Gas 2 comes into contact with gas 1 flowing through the slots through the inlet pipe in the mixer housing. The two vertical airflows achieve the first stage of mixing in the mixer housing, thereby improving the uniformity of the mixed gas.

[0019] 2. When the mixed gas after preliminary mixing passes through the semi-elliptical plate guide device arranged in the mixer shell, the mixed gas flows through two flow channels respectively, and the second stage of mixing is realized while changing the air flow channel, so that the mixed gas reaches a completely turbulent state.

[0020] In summary, the present invention can quickly complete the initial mixing of gas one and gas two in a shorter pipeline, improve the uniformity of the mixed gas, and then perform subsequent mixing in a subsequent dual-circulation channel structure, further improving the uniformity of the mixed gas and reducing the occurrence of mixed gas stratification. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a three-dimensional diagram of a gas mixing device based on shear flow proposed by the present invention.

[0022] Figure 2 This is a front view of a gas mixing device based on shear flow proposed by the present invention.

[0023] Figure 3 This is a front view of the semi-elliptical plate guide device proposed by the present invention.

[0024] Figure 4 This is a three-dimensional diagram of the semi-elliptical plate guide device proposed by the present invention.

[0025] In the figure, 1 is a gas inlet flange, 2 is a gas inlet pipe, 3 is a conical head, 4 is a gas second inlet flange, 5 is a gas second inlet pipe, 6 is a spherical head, 7 is a semi-elliptical plate, 8 is a mixer shell, 9 is a mixed gas outlet flange, and 10 is a support. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0028] Combine the following Figure 1-4 A specific embodiment of the present invention will be described.

[0029] Provide a gas mixing device based on shear flow, such as Figure 1-2 As shown, it includes a gas inlet flange 1, one side of the gas inlet flange 1 is fixedly connected to a gas inlet pipe 2, the gas inlet pipe 2 is provided with slots evenly distributed along the pipe diameter, and the end of the gas inlet pipe 2 is fixedly connected to a spherical head 6.

[0030] The gas mixing device further comprises a mixer housing 8, one end of which is fixedly connected to a conical end cap 3, and a gas inlet pipe 2 passes through the conical end cap 3. The other end of the mixer housing 8 is fixedly connected to a mixed gas outlet flange 9.

[0031] Two supports 10 are also provided outside the mixer housing 8 to facilitate the fixing and supporting of the mixer.

[0032] A second gas inlet pipe 5 is provided through the mixer housing 8, and the second gas inlet pipe 5 is vertically provided with the mixer housing 8. A second gas inlet flange 4 is fixedly connected to the inlet of the second gas inlet pipe 5.

[0033] The slots are arranged just below the outlet of the second gas inlet pipe 5; preferably, four groups of tangential slots are arranged. When the first gas flows through the slots, shear flow occurs with the second gas. By setting this structure, the turbulence of the gas near the wall is enhanced, and the first-stage mixing of the two gases is achieved.

[0034] like Figure 3-4 As shown, a semi-elliptical plate 7 is also fixedly installed in the mixer housing 8, and the semi-elliptical plate 7 is located at the end of the second gas inlet pipe 5 away from the first gas inlet flange 1.

[0035] The number of the semi-elliptical plates 7 is greater than 1 group, preferably 3 groups; each group of semi-elliptical plates 7 is a cross-shaped flow-guiding structure composed of blades, and the angle between the blades is 90°, such as Figure 3 Several groups of semi-elliptical plates 7 are sequentially connected to form a flow guiding device having two mutually intersecting gas channels, and the mixture of gas one and gas two is passed through the flow guiding device to achieve the second-level mixing of the two gases.

[0036] Preferably, the flow guiding device is coaxially arranged with the mixer housing 8 .

[0037] In order to facilitate the welding of the guide device and the mixer shell 8, it is necessary to pre-assemble and weld several groups of semi-elliptical plates, and then weld them to the mixer shell 8, so as to avoid erosion of the guide device due to excessive gas flow rate, and thus avoid failure of the guide device due to erosion.

[0038] Preferably, all parts of the device are made of stainless steel. Since hydrogen atoms easily cause hydrogen embrittlement and hydrogen corrosion to carbon steel materials, the safety of equipment use is improved by using stainless steel parts.

[0039] In the present invention, one end of the mixer housing 8 is a gas source inlet, a gas source inlet is provided above the mixer housing 8, and a gas source inlet duct 5 is vertically arranged with the mixer housing 8 to prevent flow interception and decompression. The gas 2 ejected from the gas 2 inlet duct 5 is mixed with the gas 1 flowing tangentially at the slot hole in the first stage, thereby enhancing the turbulence of the gas near the wall and allowing the two gases to be initially mixed. The horizontal mixed gas after the initial mixing passes through the semi-elliptical plate 7 to form a turbulent gas, disrupting the stratospheric distribution of the gas, changing the airflow channel while achieving the second stage of mixing, completely forming a turbulent mixed gas, and finally completing the uniform mixing of the gas. Finally, the mixed gas that has finally completed the uniform mixing is discharged through the mixed gas outlet flange 9.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A gas mixing device based on shear flow, characterized in that: The gas mixing device comprises a gas inlet flange (1), one side of the gas inlet flange (1) is fixedly connected to a gas inlet pipe (2), the gas inlet pipe (2) is provided with slots evenly distributed along the pipe diameter, and the end of the gas inlet pipe (2) is fixedly connected to a spherical head (6); The gas mixing device further comprises a mixer housing (8), one end of which is fixedly connected to a conical seal head (3), and the first gas inlet pipe (2) passes through the conical seal head (3); a second gas inlet pipe (5) is passed through the mixer housing (8), and the slot is arranged directly below the outlet of the second gas inlet pipe (5); a semi-elliptical plate (7) is also fixedly installed in the mixer housing (8), and the semi-elliptical plate (7) is located at one end of the second gas inlet pipe (5) away from the first gas inlet flange (1); The other end of the mixer housing (8) is fixedly connected to a mixed gas outlet flange (9), and two supports (10) are further provided outside the mixer housing (8).

2. A gas mixing device based on shear flow according to claim 1, characterized in that: The gas one inlet pipe (2) is provided with four groups of tangential slots, and when the gas one flows through the slots, shear flow occurs with the gas two, thereby achieving first-stage mixing of the two gases.

3. A gas mixing device based on shear flow according to claim 1, characterized in that: The number of the semi-elliptical plates (7) is greater than one group, and each group of the semi-elliptical plates (7) is a cross-shaped flow-guiding structure. Several groups of the semi-elliptical plates (7) are sequentially connected to form a flow-guiding device having two mutually intersecting gas channels, and the mixture of gas one and gas two is passed through the flow-guiding device to achieve the second-level mixing of the two gases.

4. A gas mixing device based on shear flow according to claim 3, characterized in that: The flow guide device is coaxially arranged with the mixer housing (8).

5. A gas mixing device based on shear flow according to claim 1, characterized in that: The second gas inlet pipe (5) is arranged vertically to the mixer housing (8).

6. A gas mixing device based on shear flow according to claim 5, characterized in that: The inlet of the second gas inlet pipeline (5) is fixedly connected to the second gas inlet flange (4).

7. A gas mixing device based on shear flow according to claim 1, characterized in that: The mixer housing (8) and the semi-elliptical plate (7) are both made of stainless steel.

Images