Compact distributor adapted to high-power combustion engine systems

Abstract

The application discloses a compact water distributor suitable for a high-power fuel system, comprising a water distributor body and a hydrogen return pipe, an inner cavity of the water distributor body serving as a water storage cavity, the hydrogen return pipe having an inlet end, an outlet end and an internal hydrogen return cavity, the inlet end of the hydrogen return pipe extending into the inner cavity of the water distributor body and being provided with a foaming filter screen, and the foaming filter screen being a porous filter element formed by compressing metal wire clusters. The original flow guide area and the water storage area are combined into an integrated water storage cavity (i.e. the inner cavity of the water distributor body), the separation area and the hydrogen return area are combined into an integrated hydrogen return cavity, the overall volume of the water distributor is greatly compressed through structural integration, and the structure is compact. The foaming filter screen adopted in the application has separation and blocking properties, can realize efficient and deep separation of gas and water, avoids recombination of separated gaseous hydrogen and liquid water in structure, and guarantees separation efficiency.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, specifically relating to a compact water distributor adapted to high-power fuel cell electric systems. Background Technology

[0002] In existing technologies, general-purpose fuel cell water distributors typically employ a four-zone independent structure consisting of a separation zone, a flow guiding zone, a water storage zone, and a hydrogen return zone. These designs generally suffer from large size and high weight, making them unsuitable for the integrated requirements of high-power fuel cell systems with high specific power.

[0003] For example, the utility model with authorization announcement number CN223066203U discloses a gas-water separator for a fuel cell system, including a gas-water separator body. The gas-water separator body has an inner cavity for gas-water separation. The gas-water separator body also has an inlet for introducing anode tail gas mixture into the inner cavity, a hydrogen outlet for discharging separated hydrogen, and a drain outlet for discharging separated water. The inner cavity of the gas-water separator body has vertically distributed partition plates that divide the inner cavity into a separation zone and a hydrogen return zone. The inlet is located at the upper part of the separation zone, and the hydrogen outlet is located at the upper part of the hydrogen return zone. A gap is left between the bottom of the partition plate and the bottom surface of the inner cavity for separated hydrogen and water to pass through. The inner cavity has a water storage zone below the hydrogen return zone, and the drain outlet is located at the bottom surface of the water storage zone.

[0004] For example, utility model patent CN219186189U discloses a gas-water separator for fuel cells, comprising: a shell with an air inlet at one end and an air outlet at the other end; and a plurality of partitions disposed within the shell, each partition being spaced apart between the air inlet and the air outlet, and the partitions being staggered vertically to form a multi-bend gas flow channel, the surface of each partition being provided with inclined drainage grooves. It also includes a guide plate with filter holes, one end of which extends toward the partitions and the other end toward the air inlet, so that a water storage tank is formed beneath the guide plate.

[0005] However, high-power-density gas-fired electric systems (such as those with a power output of 300kW and a power-density ratio of 900W / kg) require a large amount of space due to components such as air compressors, intercoolers, humidifiers, water pumps, and distribution manifolds. Traditional water distributors are bulky and heavy, making them unsuitable for the integration requirements of high-power-density gas-fired electric systems. Summary of the Invention

[0006] To address the aforementioned shortcomings in the prior art, this invention provides a compact water distributor adapted to high-power gas-fired power systems.

[0007] A compact water distributor adapted to a high-power gas-fired power system includes a water distributor body and a hydrogen return pipe. The inner cavity of the water distributor body serves as a water storage chamber. The water distributor body has a mixed gas inlet and a drain outlet. The hydrogen return pipe has an inlet end, an outlet end serving as a hydrogen return outlet, and an internal hydrogen return chamber. The inlet end of the hydrogen return pipe extends into the inner cavity of the water distributor body and is equipped with a foamed filter screen. The foamed filter screen is a porous filter element formed by compressing metal wire balls.

[0008] Preferably, the porosity of the foamed filter is 30%~40%. Preferably, the diameter of the metal wires in the metal wire bundle during the preparation of the foamed filter is 0.05~0.3mm. Preferably, the thickness of the foamed filter is at least 5mm. More preferably, the thickness of the foamed filter is 5~6mm.

[0009] Preferably, the hydrogen return pipe has an installation section with an enlarged inner diameter at the inlet end. The foamed filter screen is installed in the installation section. The inlet end of the hydrogen return pipe also has a fixing plate to limit the foamed filter screen and prevent it from falling out. The fixing plate has clearance holes. During installation, the foamed filter screen is assembled into the installation section of the hydrogen return pipe. Due to the enlarged inner diameter of the installation section, a stepped structure is formed on one end of the installation section, which limits the foamed filter screen. The other end, due to the fixing plate, also limits the foamed filter screen. The fixing plate and the hydrogen return pipe can be fixed by a fixing structure. For example, the fixing structure can be a snap-fit ​​connection structure, such as snap holes on the hydrogen return pipe and corresponding snap points on the fixing plate; the fixing structure can also be screws or bolts for fixing. Preferably, the fixing structure uses screws or bolts that can provide a fastening effect.

[0010] From a fluid dynamics perspective, a smoothly transitional structure is optimal, allowing fluid to flow along its path without unnecessary gaps or bulky volume. Preferably, the inner cavity of the distributor body is cylindrical, elliptical cylindrical, frustum-shaped, inverted frustum-shaped, elliptical frustum-shaped, or an inverted elliptical frustum-shaped. A cylindrical shape is preferred. While square or other shapes can also be used, they will create unnecessary gaps during fluid flow, potentially contributing to a bulkier volume.

[0011] Preferably, the hydrogen return pipe extends from the top surface of the water separator body, and the mixed gas inlet is located on the side wall of the water separator body and is higher than the inlet end of the hydrogen return pipe.

[0012] More preferably, the top surface of the water distributor body is provided with an opening, and a cover plate is provided on the side wall of the hydrogen return pipe. After the hydrogen return pipe is assembled with the water distributor body, the cover plate seals the part of the top surface opening of the water distributor body located outside the hydrogen return pipe.

[0013] More preferably, the lower surface of the cover plate has a plug portion, the top opening edge of the water distributor body has a stepped structure, the plug portion and the stepped structure are fitted together and sealed by a sealing ring; the cover plate and the water distributor body also have a fixing mechanism.

[0014] Preferably, the drain outlet is located on the bottom surface of the inner cavity, and the water distributor body is also provided with a drain valve for controlling the opening and closing of the drain outlet.

[0015] The beneficial effects of this application are: This application merges the original diversion zone and water storage zone into an integrated water storage chamber (i.e., the inner cavity of the water distributor body), and merges the separation zone and hydrogen return zone into an integrated hydrogen return chamber. Through structural integration, the overall volume of the water distributor is greatly reduced, resulting in a compact structure.

[0016] The gas-water separation process of this application is as follows: After the gas-water mixture enters the water storage chamber, it first completes the first-stage gas-water separation through the vortex effect and gravity. The liquid water is retained in the water storage chamber. The liquid-laden humid gas passes through the foaming filter to complete the second-stage deep separation. The separated dry hydrogen directly enters the hydrogen inlet of the gas-fired power system for recycling. The separated liquid water falls back into the water storage chamber for storage.

[0017] The foamed filter used in this application combines separation and barrier properties, achieving both efficient and deep separation of gas and water while structurally preventing the recombining of separated gaseous hydrogen and liquid water, thus ensuring separation efficiency. The water separator structure of this application can be flexibly adjusted to meet specific system integration needs, maximizing space savings and exhibiting excellent compatibility with highly integrated gas-fired power systems. It can be applied to systems such as 300kW gas-fired power systems, providing a novel water separation solution for high-power-density gas-fired power systems. Attached Figure Description

[0018] Figure 1 This is a first-view three-dimensional structural diagram of a compact water distributor adapted to a high-power gas-fired power system for this application.

[0019] Figure 2 This is a second-view three-dimensional structural diagram of a compact water distributor adapted to a high-power gas-fired power system for this application.

[0020] Figure 3 This is a side view of the compact water distributor adapted to a high-power gas-fired power system for this application.

[0021] Figure 4 for Figure 3 A cross-sectional view along the AA direction.

[0022] Figure 5 A first-person perspective three-dimensional structural diagram of the water distributor body after removing the hydrogen return pipe and drain valve.

[0023] Figure 6 A two-dimensional structural diagram of the water separator body after removing the hydrogen return pipe and drain valve.

[0024] Figure 7 This is a three-dimensional structural diagram of the hydrogen return pipe.

[0025] Figure 8 This is a side view of the hydrogen return pipe.

[0026] Figure 9 for Figure 8 A cross-sectional view along the BB direction.

[0027] Reference numerals: 1. Water separator body; 11. Water storage chamber; 12. Mixed gas inlet; 13. Drain outlet; 14. Stepped structure; 2. Hydrogen return pipe; 21. Hydrogen return chamber; 22. Hydrogen return outlet; 23. Foamed filter screen; 24. Mounting section; 25. Fixing plate; 251. Clearance hole; 252. Bolt; 26. Cover plate; 261. Plug; 262. Seal ring; 3. Drain valve; 4. Detailed Implementation

[0028] like Figures 1 to 9 As shown, a compact water distributor adapted to a high-power gas-fired power system includes a water distributor body 1 and a hydrogen return pipe 2. The inner cavity of the water distributor body 1 serves as a water storage chamber 11. The main body shape of the inner cavity of the water distributor body 1 can be cylindrical, elliptical cylindrical, frustum-shaped, inverted frustum-shaped, elliptical frustum-shaped, or inverted elliptical frustum-shaped. A cylindrical shape is preferred. Of course, the main body shape of the inner cavity of the water distributor body 1 can also be designed as square or other shapes, but the effect will be slightly inferior. In the structure shown in the figure, the main body shape of the inner cavity of the water distributor body 1 is cylindrical. The sidewalls of the main body of the inner cavity of the water distributor body 1 are continuous transition shapes such as arc surfaces, without sharp corners, which is conducive to the rotational flow of the gas-water mixture in the inner cavity. After the gas-water mixture enters the water storage chamber 11, the airflow can rotate, achieving gas-water separation through the vortex effect.

[0029] The water distributor body 1 has a mixed gas inlet 12 and a drain outlet 13. The mixed gas inlet 12 is located on the upper side wall of the water distributor body 1. The drain outlet 13 is located on the bottom surface of the inner cavity of the water distributor body 1, facilitating the discharge of separated water. The bottom surface of the inner cavity of the water distributor body 1 can be inclined at an angle to facilitate the flow to the drain outlet 13. The water distributor body 1 is also equipped with a drain valve 4 to control the opening and closing of the drain outlet 13, which can be controlled to open and drain water when needed.

[0030] The water separator body 1 is also equipped with a hydrogen return pipe 2, which has an inlet end, an outlet end, and an internal hydrogen return chamber 21. The bottom surface of the hydrogen return pipe 2 is the inlet end, the top surface is the outlet end, and the outlet end is the hydrogen return outlet 22 of the water separator.

[0031] The top surface of the water separator body 1 has an opening, and a cover plate 26 protrudes from the side wall of the hydrogen return pipe 2. After the hydrogen return pipe 2 is assembled with the water separator body 1, the cover plate 26 seals the part of the top surface opening of the water separator body 1 that is outside the hydrogen return pipe 2. That is, the cover plate 26 ensures that only the hydrogen return chamber 21 inside the hydrogen return pipe 2 is connected to the outside on the top surface of the water separator body 1, while the rest is sealed. The lower surface of the cover plate 26 has a plug part 261, and the edge of the top surface opening of the water separator body 1 has a stepped structure 14. The plug part 261 and the stepped structure 14 are fitted together and sealed by a sealing ring 3.

[0032] The cover plate 26 and the water distributor body 1 are also fixed by a fixing mechanism. In the structure shown in the figure, the main body of the water distributor body 1 is rectangular in shape. In addition to the internal cylindrical cavity, there is a certain amount of space at the four corners of the top surface. Bolts 262 can be used to fix the cover plate 26 to the water distributor body 1. This fixing method is convenient for disassembly and assembly.

[0033] The hydrogen return pipe 2 extends from the top surface of the water separator body 1. The mixed gas inlet 12 is located on the side wall of the water separator body 1 and is higher than the inlet end of the hydrogen return pipe. This allows the gas-water mixture entering the water storage chamber 11 from the mixed gas inlet 12 to flow along the flow channel formed by the outer wall of the hydrogen return chamber 21 and the inner wall of the water storage chamber 11. Combined with the gravity of the mixed gas, the mixed gas flows in a spiral shape within the flow channel, thus completing the first-stage gas-water separation. The inlet end of the hydrogen return pipe 2 extends into the inner cavity of the water separator body 1 and is equipped with a foamed filter screen 23. The hydrogen return pipe 2 has an enlarged inner diameter mounting section 24 at the inlet end, into which the foamed filter screen 23 is installed. The inlet end of the hydrogen return pipe 2 is also equipped with a fixing plate 25 to limit the foamed filter screen 23 and prevent it from falling out. The fixing plate 25 has a clearance hole 251 for allowing gas flow into the hydrogen return pipe 2 without obstructing the foamed filter screen 23. During installation, the foamed filter screen 23 is assembled into the mounting section 24 of the hydrogen return pipe 2. Due to the enlarged inner diameter of the mounting section 24, a stepped structure is formed at one end of the inner side of the mounting section 24, which limits the foamed filter screen 23. The other end, with the fixing plate 24, similarly limits the foamed filter screen 23. The fixing plate 25 is fixed to the hydrogen return pipe 2 using a fixing structure, as shown in the figure, which uses bolts 252.

[0034] The foamed filter screen 23 is a porous filter element formed by compressing a bundle of metal wires. The material used to prepare the foamed filter screen 23 can be stainless steel, such as 304 or 316L food-grade stainless steel wire. During the preparation of the foamed filter screen 23, the bundled metal wires are compressed and shaped by applying uniform pressure through a mold, resulting in a flat, round disc shape. The porosity of the foamed filter screen 23 is 30%~40%. The diameter of the metal wires in the bundle during the preparation of the foamed filter screen 23 is 0.05~0.3mm. The thickness of the foamed filter screen is at least 5mm, preferably 5~6mm.

[0035] The compressed foamed filter screen 23 has irregular pores, and the layers are also irregular (i.e., there are no specific layers, and it belongs to an irregular mesh structure). The metal wires on the top, bottom, left, and right are irregularly staggered, forming irregular pores. Because the pores are small and the direction is constantly changing, it is difficult for liquid molecules with large molecular size to pass through the tiny gaps that are constantly changing direction, so as to achieve gas-liquid separation and barrier function.

[0036] After molding and fixing, post-processing can be performed, including cleaning to remove oil stains. Some products will undergo passivation treatment to enhance corrosion resistance. Finally, they can be encapsulated in a stainless steel shell or used directly as a bare core. The foamed filter screen 23 mainly relies on the combination of three physical mechanisms: size sieving, surface tension retention, and gravity sedimentation, to achieve the effect of allowing only gas to pass through while blocking and separating liquids. The specific principle is as follows: Pore ​​size screening: The foamed filter screen forms uniform and interconnected pores through the foaming process. Its pore size design is adapted to the difference between gas and liquid states: gas is in the molecular state, the molecular size is much smaller than the pore size, and it has extremely strong fluidity, so it can pass through the pores smoothly; while liquid exists in the mixed air flow mostly in the form of droplets, and the diameter of the droplets is mostly larger than the pore size of the foamed screen, so they will be directly intercepted by the pores on one side of the filter screen.

[0037] Surface tension trapping effect: Even if some small droplets can get close to the pores, the surface tension properties of the liquid itself will prevent them from passing through. In particular, if the foamed filter has a hydrophobic and aerophilic surface treatment, after the liquid comes into contact with the filter, a liquid film will form on the surface of the pores. The surface tension of the liquid film will prevent the liquid from continuing to pass through the pores. Only gas can break through the liquid film and pass through the pores.

[0038] Gravity settling completes the separation: The intercepted droplets will continuously adhere to the skeleton of the foamed filter screen, gradually accumulating and growing larger. When the weight of the droplet exceeds its adhesion force, it will drip down under the action of gravity and converge at the bottom of the water storage chamber. Finally, the liquid will be discharged from the water separator through the drain valve, thus completely completing the separation of gas and liquid.

[0039] Because the mixed gas exiting the anode of the fuel cell stack is pressurized, it flows into the separator under pressure. Due to the relatively small size of the separator, the mixed gas entering the separator has a relatively high velocity. Under the influence of inertia and pressure, the mixed gas collides with the foamed filter screen. The foamed filter screen consists of multiple layers of staggered micro-pores. Hydrogen, being lightweight and low in density, is compressible. Even after multiple collisions and deflections, it retains sufficient kinetic energy to smoothly pass through the staggered pores of each filter layer. Liquid, however, is much heavier than hydrogen, denser, and incompressible. When a droplet passes through the first layer of pores, due to the irregular staggered arrangement of adjacent layers, the droplet cannot travel in a straight line and will directly collide with the framework of the second layer of pores, forcing it to change its flow direction. Each collision and deflection consumes the droplet's kinetic energy. After continuous interception by multiple layers of metal wire mesh, the remaining kinetic energy of the droplet is insufficient to support its continued passage through the staggered pores. Ultimately, it is trapped, converges along the framework, and then settles out by gravity, further improving the overall gas-liquid separation efficiency.

[0040] Detection Example 1: The performance of the water separator in this application was tested. A mixed gas (simulated using atomized liquid water) was introduced into the separator inlet, and then the separated liquid water was weighed (discharged through a drain valve). Pressure sensors were installed before and after the water separator (the front being the mixed gas inlet and the rear being the hydrogen return outlet). The difference between the two pressure sensors was the flow resistance. The flow resistance and water separation efficiency under different flow rates were verified, and it was determined whether the gas and water would overlap and how much water would be carried away under different water storage conditions.

[0041] The foamed filter used for testing is a normal steel wool ball made of 304 stainless steel wire with a wire diameter of 0.13mm. It is compressed and shaped by applying uniform pressure through a mold at room temperature, and the shaped state is a cylinder (pancake).

[0042] The test parameters and results are shown in Table 1. The cross-sectional area of ​​the foamed filter is 7 cm². 2 The inlet water rate (the inlet water rate before atomization of the atomized liquid water) is 5 ml / s, and the total inlet water flow rate during the entire testing process is 175 ml. The drain valve drains water for 5 seconds every 5 seconds. Water separation efficiency (%) = drain volume / total inlet water flow rate × 100%.

[0043] Table 1

[0044] As can be seen from the results in Table 1, the water separation efficiency decreased after the porosity was increased; the measured flow resistance increased after the porosity was decreased; increasing the thickness of the foamed filter screen can improve the water separation efficiency, but the increase in thickness means an increase in cost.

[0045] The thickness of the foamed filter screen is preferably at least 5mm. If it is too thin, the manufacturing process becomes more difficult to achieve a certain porosity, thus increasing costs. Considering that a thicker screen increases the composition of the material, further increasing the thickness after the water separation efficiency has reached a certain level becomes less economical, a thickness of 5-6mm is preferred for the foamed filter screen.

[0046] The optimal porosity for foamed filter screens is 30% to 40%. When the porosity is below 30%, filtration performance decreases, the internal pores of the filter screen are easily compacted, the resistance to fluid flow increases significantly, and the filtration speed cannot increase in tandem with pressure. Conversely, if the porosity is too high, the water separation efficiency will decrease.

Claims

1. A compact water distributor adapted to high-power gas-fired power systems, characterized in that, It includes a water separator body and a hydrogen return pipe. The inner cavity of the water separator body serves as a water storage chamber. The water separator body has a mixed gas inlet and a drain outlet. The hydrogen return pipe has an inlet end, an outlet end that serves as the hydrogen return outlet, and an internal hydrogen return chamber. The inlet end of the hydrogen return pipe extends into the inner cavity of the water separator body and is equipped with a foamed filter screen, which is a porous filter element formed by compressing metal wire balls.

2. The compact water distributor adapted to high-power gas-fired power systems according to claim 1, characterized in that, The porosity of the foamed filter screen is 30%~40%.

3. The compact water distributor adapted to high-power gas-fired power systems according to claim 1, characterized in that, The metal wires in the metal wire bundle during the preparation of the foamed filter have a diameter of 0.05~0.3mm.

4. The compact water distributor adapted to high-power gas-fired power systems according to claim 1, characterized in that, The thickness of the foamed filter screen is at least 5 mm.

5. The compact water distributor adapted to high-power gas-fired power systems according to claim 1, characterized in that, The hydrogen return pipe has an installation section with an enlarged inner diameter at the inlet end. The foamed filter screen is installed in the installation section. The inlet end of the hydrogen return pipe is also provided with a fixing plate to limit the foamed filter screen and prevent it from falling out. The fixing plate is provided with clearance holes.

6. The compact water distributor adapted to high-power gas-fired power systems according to claim 1, characterized in that, The inner cavity of the water distributor body is cylindrical, elliptical cylindrical, frustum-shaped, inverted frustum-shaped, elliptical frustum-shaped, or inverted elliptical frustum-shaped.

7. The compact water distributor adapted to a high-power gas-fired power system according to claim 1, characterized in that, The hydrogen return pipe extends from the top surface of the water separator body, and the mixed gas inlet is located on the side wall of the water separator body and is higher than the inlet end of the hydrogen return pipe.

8. The compact water distributor adapted to a high-power gas-fired power system according to claim 7, characterized in that, The top surface of the water distributor body is provided with an opening, and a cover plate protrudes from the side wall of the hydrogen return pipe. After the hydrogen return pipe is assembled with the water distributor body, the cover plate seals the part of the top surface opening of the water distributor body located outside the hydrogen return pipe.

9. The compact water distributor adapted to a high-power gas-fired power system according to claim 8, characterized in that, The cover plate has a plug on its lower surface, and the top opening edge of the water distributor body has a stepped structure. The plug and the stepped structure are fitted together and sealed by a sealing ring. The cover plate and the water distributor body also have a fixing mechanism.

10. The compact water distributor adapted to a high-power gas-fired power system according to claim 1, characterized in that, The drain outlet is located on the bottom surface of the inner cavity, and the water distributor body is also provided with a drain valve to control the opening and closing of the drain outlet.

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