A natural gas ammonia blending mechanism

Abstract

The utility model belongs to the field of energy environmental protection technology especially a kind of natural gas ammonia blending mechanism, including base, the upper surface of the base is fixedly installed with mixing tank, the upper surface of the mixing tank is fixedly communicated with initiative gas conveying pipe, the outside of the mixing tank is fixedly communicated with follow-up gas conveying pipe.The natural gas ammonia blending mechanism is provided with mixing device, can be fully mixed to ammonia gas and natural gas in mixing tank, by the combination of helical blade, mixed air outlet groove and mixing blade, can improve mixing efficiency, so that mixing is uniform, the inner wall shape of mixed air outlet groove is tesla valve, when gas flows, two branches will be formed, two kinds of branches will then converge together, just increase the flow velocity and mixing degree of gas, by the distribution of the inclined shape of mixing blade, the gas conveyed can be guided, rotate in mixing tank, can be mixed again.

Description

Technical Field

[0001] This utility model relates to the field of energy and environmental protection technology, and in particular to a natural gas ammonia blending mechanism. Background Technology

[0002] Hydrogen-blended natural gas is a cleaner, lower-carbon fuel than pure natural gas, reducing carbon emissions from end-use energy. It can also replace some natural gas consumption with hydrogen; based on a blending ratio of 10% to 20%, it is estimated to replace 10 to 20 billion cubic meters of natural gas annually, alleviating natural gas supply shortages to some extent. However, hydrogen, as a clean fuel, has high combustion costs, requires storage and transportation at -253°C or high pressure, and carries risks of leakage and explosion, resulting in low transportation efficiency. Ammonia, a more readily available fuel than hydrogen, although with a lower calorific value, does not produce carbon dioxide during combustion and is suitable for long-distance, long-term storage and transportation. It can replace hydrogen in blended combustion with natural gas, which is significant for achieving a "dual-carbon" energy conversion.

[0003] Chinese Patent No. CN216868191U discloses a static natural gas hydrogen blending mechanism, characterized by comprising a base, a static mixer, an active gas input pipe, an active gas input valve, an active gas flow meter, a follower gas input pipe, a follower gas input valve, a follower gas flow meter, a mixed gas output pipe, a methane analyzer, a mixed gas flow meter, a filter device, a check valve, a calorific value meter, a mixed gas output valve, a drain valve, and a control cabinet. The overall design employs a variable proportion and variable flow rate mixing concept, allowing hydrogen and natural gas to enter the mixer in a specific ratio. The methane analyzer and flow meter at the mixed gas outlet automatically adjust the opening of the hydrogen flow regulating valve, outputting a mixed gas that meets the requirements. Combined with an intelligent control mechanism, it monitors flow and pressure parameters, automatically controls methane concentration and mixed gas calorific value, improving the controllability of the mixture, providing high monitoring accuracy, sensitive response, and safer and more stable operation.

[0004] However, the above scheme, which mixes natural gas and ammonia using a static mixer, cannot achieve sufficient mixing between the two gases, resulting in uneven mixing. This uneven mixing leads to localized fuel ratio imbalances. In areas with excessively high natural gas concentrations, incomplete combustion may occur due to insufficient oxygen or ammonia, producing carbon monoxide, unburned hydrocarbons, and soot, reducing thermal efficiency and wasting fuel. In areas with excessively high ammonia concentrations, the excess ammonia absorbs heat, lowering the flame temperature and potentially leading to incomplete combustion as well. High concentrations of ammonia may also be difficult to ignite or maintain stable combustion, increasing the formation of nitrogen oxides. Utility Model Content

[0005] Based on the technical problem that existing natural gas ammonia blending mechanisms result in uneven mixing of ammonia and natural gas, leading to localized fuel ratio imbalances and increased nitrogen oxide generation, this utility model proposes a natural gas ammonia blending mechanism.

[0006] The present invention discloses a natural gas ammonia blending mechanism, comprising a base, a mixing tank fixedly mounted on the upper surface of the base, an active gas delivery pipe fixedly connected to the upper surface of the mixing tank, and a follower gas delivery pipe fixedly connected to the outer side of the mixing tank.

[0007] The upper surface is provided with a mixing device, which includes mixing blades that mix ammonia and natural gas in the mixing tank.

[0008] Preferably, an input valve is fixedly installed on the outer surface of both the active gas delivery pipe and the follower gas delivery pipe, and a gas flow meter is fixedly installed on the outer surface of both the active gas delivery pipe and the follower gas delivery pipe.

[0009] Through the above technical solution, natural gas can be transported through the active gas delivery pipe, and ammonia can be transported through the follower gas delivery pipe. One end of the active gas delivery pipe is inserted into the mixing tank, and one end of the active gas delivery pipe is inclined, which facilitates the natural gas transported in the active gas delivery pipe to flow in one direction. The axis of the follower gas delivery pipe and the axis of the mixing tank are on the same horizontal line, which can blow the natural gas transported by the active gas delivery pipe, which facilitates mixing and speeds up the flow.

[0010] Preferably, the mixing device further includes a spiral blade, which is fixedly installed on the inner wall of the mixing tank. A centralized pipe is fixedly installed on the inner wall of the mixing tank, and a mixing air outlet groove is formed on the inner wall of the centralized pipe.

[0011] Through the above technical solution, the conveyed gas can be divided and mixed by the spiral blades. The spiral blades are twisted 180 degrees, and the adjacent spiral blades rotate in opposite directions and are offset by 90 degrees. When the gas passes through, it generates diversion, cross mixing and reverse swirling flow, which improves the mixing efficiency. The outer surface of the concentrating pipe is funnel-shaped, which allows the diffused airflow to be concentrated and enter the mixing outlet groove. The inner wall of the mixing outlet groove is shaped like a Tesla valve. When the gas flows, it will form two branches, and the two branches will then converge, which increases the gas flow speed and the degree of mixing.

[0012] Preferably, a support frame is fixedly installed on the inner wall of the mixing tank, the outer surface of the support frame is rotatably connected to one end of the mixing blade, a sealing ring is fixedly installed on the outer surface of the mixing tank, and one end of the mixing blade is rotatably connected to the outer surface of the sealing ring.

[0013] Through the above technical solution, in order to remix the gas, the gas can be guided by the inclined shape of the mixing blades and rotated in the mixing tank to achieve remixing.

[0014] Preferably, a connecting plate is fixedly installed on the outer surface of the mixing blade, a rotating ring is rotatably connected to the outer surface of the mixing tank, a roller is rotatably connected to the outer surface of the rotating ring, and the outer surface of the roller is slidably inserted into the inner wall of the groove of the connecting plate.

[0015] Through the above technical solution, in order to adjust the angle of the mixing blades, the rotation of the rotating ring can drive the connecting plate to deflect, thereby achieving the deflection angle of the mixing blades and adjusting the angle of the guide flow.

[0016] Preferably, a drive motor is fixedly installed on the outer surface of the mixing tank, a drive gear is fixedly installed at one end of the output shaft of the drive motor, and a drive gear ring is fixedly installed on the outer surface of the rotating ring, with the drive gear meshing with the drive gear ring.

[0017] Through the above technical solution, in order to automatically drive the rotating ring to rotate, the drive motor drives the drive gear ring to rotate through the drive gear, thereby driving the rotating ring to rotate.

[0018] Preferably, a funnel-shaped output pipe is fixedly installed on the inner wall of the mixing tank, an output pipe with a control valve is fixedly installed on the upper surface of the mixing tank, a methane analyzer is fixedly installed on the outer surface of the output pipe, a mixed gas flow meter is fixedly installed on the outer surface of the output pipe, and a calorific value meter is fixedly installed on the outer surface of the output pipe.

[0019] Through the above technical solution, in order to output and detect the mixed gas in the mixing tank, a methane analyzer is used to detect and analyze the gas in the output pipeline. The content of components such as methane, nitrogen, and carbon dioxide can be analyzed in real time, and parameters such as calorific value, density, and vaporization rate can be output simultaneously. A mixed gas flow meter detects the flow rate in the output pipeline, and a calorific value meter calculates the calorific value of the gas in real time to ensure the stable efficiency of the terminal combustion equipment.

[0020] The beneficial effects of this utility model are as follows: By setting up a mixing device, ammonia and natural gas in the mixing tank can be fully mixed. The combination of spiral blades, mixing outlet ducts, and mixing blades can improve mixing efficiency and make the mixing uniform. The inner wall of the mixing outlet duct is shaped like a Tesla valve. When the gas flows, it forms two branches, which then converge, increasing the gas flow speed and mixing degree. The inclined distribution of the mixing blades can guide the transported gas and make it rotate in the mixing tank for further mixing. The mixing blades can adjust their angle according to the mixing ratio and mixing conditions. This solves the technical problem of uneven mixing of ammonia and natural gas in existing natural gas blending mechanisms, which leads to local fuel ratio imbalance and increased nitrogen oxide generation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a natural gas ammonia blending mechanism proposed in this utility model; Figure 2 This is a perspective view of the spiral plate structure of a natural gas ammonia blending mechanism proposed in this utility model; Figure 3 This is a perspective view of the centralized pipeline structure of a natural gas ammonia blending mechanism proposed in this utility model; Figure 4 This is a perspective view of the mixing air outlet trough structure of a natural gas ammonia blending mechanism proposed in this utility model; Figure 5 This is a perspective view of the rotating ring structure of a natural gas ammonia blending mechanism proposed in this utility model; Figure 6 This is a perspective view of the mixing blade structure of a natural gas ammonia blending mechanism proposed in this utility model; Figure 7 This is a perspective view of the connecting plate structure of a natural gas ammonia blending mechanism proposed in this utility model.

[0022] In the diagram: 1. Base; 11. Mixing tank; 12. Active gas delivery pipe; 13. Follow-up gas delivery pipe; 14. Input valve; 15. Gas flow meter; 2. Spiral vane; 21. Centralized pipeline; 22. Mixing outlet duct; 3. Support frame; 31. Mixing blades; 32. Sealing ring; 33. Connecting plate; 34. Rotating ring; 35. Roller; 36. Drive motor; 37. Drive gear; 38. Drive gear ring; 4. Funnel outlet pipe; 41. Outlet pipe; 42. Methane analyzer; 43. Mixed gas flow meter; 44. Calorific value meter. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0024] Reference Figures 1-7 A natural gas ammonia blending mechanism includes a base 1, a mixing tank 11 fixedly installed on the upper surface of the base 1, an active gas delivery pipe 12 fixedly connected to the upper surface of the mixing tank 11, a follower gas delivery pipe 13 fixedly connected to the outer side of the mixing tank 11, and a drain valve fixedly connected to the outer surface of the mixing tank 11 for draining.

[0025] Specifically, for the transportation of ammonia and natural gas, an input valve 14 is fixedly installed on the outer surface of both the active gas delivery pipe 12 and the follower gas delivery pipe 13. A gas flow meter 15 is fixedly installed on the outer surface of both the active gas delivery pipe 12 and the follower gas delivery pipe 13. The gas flow meter 15 on the active gas delivery pipe 12 is of the DN50-DN300 series, and the gas flow meter 15 on the follower gas delivery pipe 13 is of the BTLUGB-50 model. Natural gas can be transported through the active gas delivery pipe 12, and ammonia can be transported through the follower gas delivery pipe 13. One end of the active gas delivery pipe 12 is inserted into the mixing tank 11, and one end of the active gas delivery pipe 12 is inclined to facilitate the flow of natural gas transported in the active gas delivery pipe 12 in one direction. The axis of the follower gas delivery pipe 13 and the axis of the mixing tank 11 are on the same horizontal line, which can blow the natural gas transported by the active gas delivery pipe 12 to facilitate mixing and accelerate the flow speed.

[0026] In order to mix ammonia and natural gas, a mixing device is provided on the upper surface. The mixing device includes mixing blades 31, which mix the ammonia and natural gas in the mixing tank 11.

[0027] Specifically, to improve mixing efficiency, the mixing device also includes a spiral blade 2, which is fixedly installed on the inner wall of the mixing tank 11. A centralized pipe 21 is fixedly installed on the inner wall of the mixing tank 11, and a mixing outlet groove 22 is opened on the inner wall of the centralized pipe 21. The spiral blade 2 can divide and mix the conveyed gas. The spiral blade 2 is twisted at 180 degrees, and the rotation directions of adjacent spiral blades 2 are opposite and offset by 90 degrees. When the gas passes through, it generates diversion, cross mixing and reverse swirling flow, which improves the mixing efficiency. The outer surface of the centralized pipe 21 is funnel-shaped, which allows the diffused airflow to be concentrated and enter the mixing outlet groove 22. The inner wall of the mixing outlet groove 22 is shaped like a Tesla valve. When the gas flows, it will form two branches, and the two branches will then converge, which increases the gas flow speed and mixing degree.

[0028] Specifically, in order to support the mixing blade 31, a support frame 3 is fixedly installed on the inner wall of the mixing tank 11. The outer surface of the support frame 3 is rotatably connected to one end of the mixing blade 31. A sealing ring 32 is fixedly installed on the outer surface of the mixing tank 11. One end of the mixing blade 31 is rotatably connected to the outer surface of the sealing ring 32. A sealing component can be provided at the connection.

[0029] Specifically, in order to change the angle of the mixing blade 31 and adjust the direction of the flow, a connecting plate 33 is fixedly installed on the outer surface of the mixing blade 31, a rotating ring 34 is rotatably connected to the outer surface of the mixing tank 11, a roller 35 is rotatably connected to the outer surface of the rotating ring 34, and the outer surface of the roller 35 is slidably inserted into the inner wall of the groove of the connecting plate 33.

[0030] Specifically, in order to automatically drive the rotating ring 34 to rotate, a drive motor 36 is fixedly installed on the outer surface of the mixing tank 11. The drive motor 36 is a compact BLDC motor 20cm, which achieves arcsecond-level accuracy through an inductive position sensor IPS2200 / IPS2550. A drive gear 37 is fixedly installed at one end of the output shaft of the drive motor 36, and a drive gear ring 38 is fixedly installed on the outer surface of the rotating ring 34. The drive gear 37 meshes with the drive gear ring 38. A protective shell can be set on the outside to protect the drive gear 37, the rotating ring 34 and the connecting plate 33.

[0031] Specifically, in order to test the mixed ammonia and natural gas, a funnel-shaped output pipe 4 is fixedly installed on the inner wall of the mixing tank 11, an output pipe 41 with a control valve is fixedly installed on the upper surface of the mixing tank 11, a methane analyzer 42 is fixedly installed on the outer surface of the output pipe 41, a mixed gas flow meter 43 is fixedly installed on the outer surface of the output pipe 41, and a calorific value meter 44 is fixedly installed on the outer surface of the output pipe 41.

[0032] Through the above technical solution, in order to output and detect the mixed gas in the mixing tank 11, the methane analyzer 42 detects and analyzes the gas in the output pipe 41, and can analyze the content of components such as methane, nitrogen, and carbon dioxide in real time, and output parameters such as calorific value, density, and vaporization rate simultaneously. The mixed gas flow meter 43 detects the flow rate transported in the output pipe 41, and the calorific value meter 44 calculates the calorific value of the gas in real time to ensure the stable efficiency of the terminal combustion equipment.

[0033] By setting up a mixing device, ammonia and natural gas in the mixing tank 11 can be fully mixed. The combination of spiral blades 2, mixing outlet duct 22 and mixing blades 31 can improve mixing efficiency and make the mixing uniform. The inner wall of the mixing outlet duct 22 is shaped like a Tesla valve. When the gas flows, it will form two branches, which will then converge, thus increasing the gas flow speed and mixing degree. The inclined distribution of the mixing blades 31 can guide the transported gas and make it rotate in the mixing tank 11 for further mixing. The mixing blades 31 can adjust the blade angle according to the mixing ratio and mixing conditions, thus solving the technical problem of uneven mixing of ammonia and natural gas in existing natural gas blending mechanisms, which leads to local fuel ratio imbalance and increased nitrogen oxide generation.

[0034] Working principle: In the existing natural gas ammonia blending process, ammonia is introduced from the liquid ammonia storage tank via a transfer pump and then enters the liquid ammonia evaporator. Part of the liquid ammonia flows back to the liquid ammonia storage tank. The liquid ammonia pipeline is equipped with a regulating valve and an emergency shut-off valve. The regulating valve is interlocked with the liquid ammonia level gauge of the liquid ammonia evaporator to control the liquid ammonia level in the evaporator and prevent it from becoming too high. The liquid ammonia evaporator adopts a steam-heated vaporizer and a coaxial sleeve evaporator. The saturated steam in the inner tube heats the condensate flowing in the opposite direction in the outer tube during the upward process. The condensate in the outer tube then evenly transfers heat to the liquid ammonia in the outer tube bundle at a relatively mild temperature. After absorbing heat, the liquid ammonia vaporizes and, after being pressurized to the required pressure by the regulating valve, enters the ammonia buffer tank for natural gas blending. The natural gas inlet pipeline is equipped with a filter, flow meter and regulating valve, and the ammonia pipeline is also equipped with a flow meter and regulating valve. The opening of the ammonia regulating valve is automatically adjusted by the flow rates of natural gas and ammonia to adjust the mixing ratio of the two gases. The above is the existing technology. Natural gas enters the mixing tank 11 via the main gas delivery pipe 12, and ammonia enters via the follower gas delivery pipe 13. After initial mixing via the spiral vane 2, the mixture enters the central pipe 21 and then the mixing outlet trough 22. After further mixing, the mixture is dispersed and then rotated by the mixing blades 31. After further mixing, the mixture enters the output pipe 41 via the funnel delivery pipe. The gas is detected by the methane analyzer 42, the gas flow meter 43 can detect the gas flow rate, and the calorific value meter 44 calculates the gas calorific value in real time to ensure stable efficiency of the terminal combustion equipment. When it is necessary to adjust the tilt angle of the mixing blade 31, the drive motor 36 is started to drive the drive gear 37 to rotate, and the drive gear ring 38 drives the rotating ring 34 to rotate, so that the roller 35 can drive the connecting plate 33 to deflect and change the angle of the mixing blade 31.

[0035] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A natural gas ammonia blending mechanism, comprising a base (1), characterized in that: A mixing tank (11) is fixedly installed on the upper surface of the base (1), and an active gas delivery pipe (12) is fixedly connected to the upper surface of the mixing tank (11), and a follower gas delivery pipe (13) is fixedly connected to the outer side of the mixing tank (11). The upper surface is provided with a mixing device, which includes mixing blades (31) that mix ammonia and natural gas in the mixing tank (11).

2. The natural gas ammonia blending mechanism according to claim 1, characterized in that: An input valve (14) is fixedly installed on the outer surface of both the active gas delivery pipe (12) and the follower gas delivery pipe (13), and a gas flow meter (15) is fixedly installed on the outer surface of both the active gas delivery pipe (12) and the follower gas delivery pipe (13).

3. A natural gas ammonia blending mechanism according to claim 1, characterized in that: The mixing device also includes a spiral blade (2), which is fixedly installed on the inner wall of the mixing tank (11). A central pipe (21) is fixedly installed on the inner wall of the mixing tank (11), and a mixing air outlet groove (22) is opened on the inner wall of the central pipe (21).

4. A natural gas ammonia blending mechanism according to claim 1, characterized in that: The inner wall of the mixing tank (11) is fixedly installed with a support frame (3), the outer surface of the support frame (3) is rotatably connected to one end of the mixing blade (31), and a sealing ring (32) is fixedly installed on the outer surface of the mixing tank (11), and one end of the mixing blade (31) is rotatably connected to the outer surface of the sealing ring (32).

5. A natural gas ammonia blending mechanism according to claim 4, characterized in that: A connecting plate (33) is fixedly installed on the outer surface of the mixing blade (31), and a rotating ring (34) is rotatably connected to the outer surface of the mixing tank (11). A roller (35) is rotatably connected to the outer surface of the rotating ring (34), and the outer surface of the roller (35) is slidably inserted into the groove inner wall of the connecting plate (33).

6. A natural gas ammonia blending mechanism according to claim 5, characterized in that: A drive motor (36) is fixedly installed on the outer surface of the mixing tank (11). A drive gear (37) is fixedly installed at one end of the output shaft of the drive motor (36). A drive gear ring (38) is fixedly installed on the outer surface of the rotating ring (34). The drive gear (37) meshes with the drive gear ring (38).

7. A natural gas ammonia blending mechanism according to claim 1, characterized in that: The inner wall of the mixing tank (11) is fixedly installed with a funnel output pipe (4), the upper surface of the mixing tank (11) is fixedly installed with an output pipe (41) with a control valve, the outer surface of the output pipe (41) is fixedly installed with a methane analyzer (42), the outer surface of the output pipe (41) is fixedly installed with a mixed gas flow meter (43), and the outer surface of the output pipe (41) is fixedly installed with a calorific value meter (44).

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