Multi-stage rotational flow-gravity combined type hydrogen-water separator for hydrogen production by alkaline electrolysis of water

Abstract

The invention relates to the technical field of separators, in particular to a multi-stage rotational flow-gravity combined type hydrogen-water separator for hydrogen production through alkaline electrolysis of water, which comprises a separation tank with a closed cavity inside, and a hydrogen-water mixed liquid inlet pipe, a gas outlet pipe and a return pipe which are communicated with the cavity are arranged on the separation tank. A rotational flow area, a transition buffer area and a gravity settling area are sequentially arranged in the cavity body from top to bottom, the rotational flow area is used for enabling mixed liquid to swirl and separating gas and liquid, and the transition buffer area is used for slowing down the flowing speed of the liquid and removing small bubbles left in the liquid. A rotational flow area, a transition buffer area and a gravity settling area are formed in a closed cavity of a separation tank from top to bottom, mixed liquid in the gravity settling area is input, rising gas carries a small amount of liquid and is buffered in the transition buffer area, residual small bubbles in the liquid are removed, the rising gas enters the rotational flow area for rotational flow, and the gas and the liquid are separated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of separators, in particular to a multi-stage cyclone-gravity composite hydrogen-water separator for hydrogen production by alkaline electrolysis of water. BACKGROUND

[0002] With the decrease of renewable energy power generation cost, large-scale hydrogen production has become a trend. The hydrogen-water separator, as the core unit of the alkaline electrolysis of water hydrogen production system, directly affects the hydrogen production efficiency. The upgrading of technology to adapt to large-scale demand is imminent. The hydrogen-water separator has developed through three generations: early gravity settling type, followed by single-stage cyclone type, and filter type separator. However, the existing technology cannot match large-scale conditions, and the pain points are significant: first, the separation precision is insufficient, and small bubbles are not captured completely; second, the load adaptability is poor, and the fluctuation of electrolysis load leads to a significant decrease in separation efficiency when the gas content changes; third, the sealing reliability is low, and the alkaline electrolyte easily corrodes the sealing components to cause leakage, resulting in high maintenance cost and restricting the large-scale application. The traditional separator has low efficiency under alkaline conditions, poor adaptability to gas content fluctuation, and unreliable sealing. SUMMARY

[0003] The technical problem to be solved by the present application is to solve the problems of low efficiency, poor adaptability to gas content fluctuation, and unreliable sealing of traditional separators under alkaline conditions. The present application provides a multi-stage cyclone-gravity composite hydrogen-water separator for hydrogen production by alkaline electrolysis of water.

[0004] The technical solution adopted by the present application to solve the technical problem is a multi-stage cyclone-gravity composite hydrogen-water separator for hydrogen production by alkaline electrolysis of water, comprising a separation tank with a closed cavity inside, a hydrogen-water mixture inlet pipe, an exhaust pipe, and a reflux pipe are arranged on the separation tank and communicate with the cavity, a cyclone zone, a transition buffer zone, and a gravity settling zone are arranged in the cavity from top to bottom, the cyclone zone is used for making the mixture flow and separating gas and liquid, the transition buffer zone is used for slowing down the flow speed of the liquid and removing small bubbles remaining in the liquid, the gravity settling zone is used for collecting the sinking liquid, the hydrogen-water mixture inlet pipe and the reflux pipe are in communication with the gravity settling zone, the hydrogen-water mixture inlet pipe is located above the reflux pipe, and the exhaust pipe is in communication with the cyclone zone. Compared with the prior art, the present application forms a cyclone zone, a transition buffer zone, and a gravity settling zone in the closed cavity of the separation tank from top to bottom, inputs the mixture into the gravity settling zone, realizes gas on the top and liquid on the bottom, the rising gas carries a small amount of liquid into the transition buffer zone for buffering and removing small bubbles remaining in the liquid, and then enters the cyclone zone for cyclone and separation of gas and liquid. The separated liquid enters the gravity settling zone, realizing the separation of the mixture along its path and the efficient coalescence and separation of small bubbles.

[0005] In order to realize the formation of the vortex zone, the transition buffer zone and the gravity settling zone from top to bottom in the cavity, preferably some embodiments, the tube distribution disc and the flow uniformity plate are arranged in the cavity from top to bottom, the vortex zone is formed between the tube distribution disc and the cavity, the transition buffer zone is formed between the tube distribution disc and the flow uniformity plate, the gravity settling zone is formed between the flow uniformity plate and the cavity, the first through holes are uniformly distributed on the tube distribution disc, the first through holes connect the vortex zone and the transition buffer zone, the flow uniformity plate is arranged in the cavity, the second through holes are arranged on the flow uniformity plate, and the second through holes connect the transition buffer zone and the gravity settling zone. By arranging the tube distribution disc and the flow uniformity plate in the cavity from top to bottom, the vortex zone, the transition buffer zone and the gravity settling zone are formed from top to bottom, which is simple in structure and convenient for installation and manufacturing.

[0006] In order to realize the interception of the residual micro-bubbles in the sinking liquid in the gravity settling zone, preferably some embodiments, the porous plate for intercepting the residual micro-bubbles in the sinking liquid is arranged in the gravity settling zone. By arranging the porous plate in the gravity settling zone, the residual micro-bubbles in the sinking liquid are intercepted through the porous plate.

[0007] In order to better intercept the residual micro-bubbles in the sinking liquid, preferably some embodiments, the third through holes are arranged on the porous plate.

[0008] In some preferred embodiments, the porous plate is arranged in multiple, and the multiple porous plates are arranged in intervals and staggered. As the last filtering link before the liquid outlet, the porous plate can accurately intercept the residual small bubbles in the sinking liquid, and through forced bubble rising separation, the residual amount of hydrogen gas in the outlet lye is controlled to be less than 0.2 g / L, the efficiency of hydrogen gas separation is further improved, the liquid uniformly flows to the reflux pipe, the problem of gas accumulation caused by liquid accumulation at the bottom is avoided, and the continuity and stability of liquid reflux are ensured.

[0009] In some preferred embodiments, the spacing between the adjacent two second through holes from the outside to the inside of the flow uniformity plate gradually decreases. Through the porous flow uniformity plate, the turbulence cutting is increased, the constraint of the lye on the small bubbles is broken, the efficiency of small bubble coalescence is improved, the second through hole enhances the frequency of bubble collision at a lower flow rate, thereby effectively promoting bubble coalescence, breaking through the traditional separation bottleneck, and the separation effect of the bubbles after this stage can ensure that the purity of hydrogen gas reaches more than 99.8%, meeting the needs of efficient separation. During the falling process of the liquid reflux, the liquid falls on the porous plate and the pipeline, and the porous plate and the pipeline jointly act to effectively slow down the liquid flow speed and reduce the turbulent flow of the liquid. This stage can appropriately reduce the liquid flow speed to prepare for the next stage.

[0010] Preferably, in some embodiments, the first through holes gradually decrease in spacing from the outer to the inner of the distribution disc. The distribution disc is used to uniformly distribute the mixed liquid to the cyclone separation cavity, effectively avoiding the disturbance of the inlet flow field, ensuring the stable rising of the bubbles in the cyclone area, and improving the uniformity of the flow field of the distribution disc, which not only improves the gas-liquid separation efficiency, but also reduces the viscous resistance of the lye, adapts to the 5%-20% gas content fluctuation condition, and solves the separation efficiency fluctuation problem caused by the non-uniform flow field of the traditional separation equipment.

[0011] In order to better separate the liquid in the transition buffer zone, preferably, in some embodiments, the transition buffer zone is provided with a condensing mechanism for condensing liquid in gas and reducing impurity interference. By providing a condensing mechanism in the transition buffer zone, the condensing mechanism condenses liquid in gas, reducing impurity interference in gas.

[0012] In order to realize the condensing mechanism, preferably, in some embodiments, the condensing mechanism comprises a condensing outer shell, the outer shell is provided with a condensing channel corresponding to and communicating with the first through hole of the distribution disc, the condensing outer shell is provided with a condensing cavity, and the condensing outer shell is provided with an input pipe and an output end, both of which communicate with the condensing cavity.

[0013] Preferably, in some embodiments, the separation tank is provided with supporting feet.

[0014] The beneficial effects of the present application are: the multi-stage cyclone-gravity combined hydrogen-water separator for alkaline electrolytic water hydrogen production in the present application forms a cyclone area, a transition buffer zone and a gravity settling area from top to bottom in the closed cavity of the separation tank during use, inputs the mixed liquid into the gravity settling area, realizes gas on the top and liquid on the bottom, the rising gas carries a small amount of liquid into the transition buffer zone for buffering and removing small gas bubbles in the liquid, and then enters the cyclone area for cyclone and separation of gas and liquid, the separated liquid enters the gravity settling area, separates the mixed liquid along its path, and efficiently coalesces and separates small gas bubbles, realizes the cooperation of "front flow uniformization-intermediate coalescence-terminal filtration", constructs an efficient gas-liquid separation system, accurately adjusts the fluid flow field and bubble coalescence, greatly improves the separation efficiency and the stability of the equipment, ensures that the purity of hydrogen gas in the process of alkaline electrolytic water hydrogen production is maintained at more than 99.9%, and the residual amount of liquid hydrogen is less than 0.2g / L, thereby meeting the efficient and stable hydrogen separation demand, and avoiding the problems of low efficiency, poor adaptability to gas content fluctuation and unreliable sealing of the traditional separator under alkaline conditions. BRIEF DESCRIPTION OF DRAWINGS

[0015] The present application will be further described below in combination with the drawings and examples.

[0016] Figure 1 is a three-dimensional structure schematic diagram of the present application; Figure 2 is the front view of the present application; Figure 3 is Figure 2 is the A-A sectional view of the present application; Figure 4 is the plan view of the flow uniforming plate of the present application; Figure 5 is the plan view of the porous plate of the present application.

[0017] In the figure: 1, separation tank, 2, cavity body, 3, hydrogen water mixture inlet pipe, 4, gas outlet pipe, 5, reflux pipe, 6, cyclone zone, 7, transition buffer zone, 8, gravity settling zone, 9, pipe distribution disc, 10, flow uniforming plate, 11, first through hole, 12, second through hole, 13, porous plate, 14, third through hole, 15, condensation outer shell, 16, condensation channel, 17, input pipe, 18, output end, 19, support leg. DETAILED DESCRIPTION

[0018] As Figures 1-5 shown, a multi-stage cyclone-gravity combined hydrogen water separator for hydrogen production by alkaline electrolytic water includes a separation tank 1 with a closed cavity body 2 inside, the separation tank 1 is provided with a hydrogen water mixture inlet pipe 3, a gas outlet pipe 4 and a reflux pipe 5 which communicate with the cavity body 2, the cavity body 2 is sequentially provided with a cyclone zone 6, a transition buffer zone 7 and a gravity settling zone 8 from top to bottom, the cyclone zone 6 is used for making the mixture cyclone and separating gas and liquid, the transition buffer zone 7 is used for slowing down the flow speed of the liquid and removing small gas bubbles remaining in the liquid, the gravity settling zone 8 is used for collecting the sinking liquid, the hydrogen water mixture inlet pipe 3 and the reflux pipe 5 both communicate with the gravity settling zone 8, the hydrogen water mixture inlet pipe 3 is located above the reflux pipe 5, and the gas outlet pipe 4 communicates with the cyclone zone 6.

[0019] The pipe distribution disc 9 and the flow uniforming plate 10 are spaced apart and arranged in the cavity body 2 from top to bottom, the cyclone zone 6 is formed between the top of the pipe distribution disc 9 and the cavity body 2, the transition buffer zone 7 is formed between the pipe distribution disc 9 and the flow uniforming plate 10, and the gravity settling zone 8 is formed between the flow uniforming plate 10 and the cavity body 2, the pipe distribution disc 9 is uniformly provided with a plurality of first through holes 11 which communicate the cyclone zone 6 and the transition buffer zone 7, the flow uniforming plate 10 is obliquely arranged in the cavity body 2, the flow uniforming plate 10 is provided with a second through hole 12 which communicates the transition buffer zone 7 and the gravity settling zone 8.

[0020] The gravity settling zone 8 is provided with a porous plate 13 which is used for intercepting small gas bubbles remaining in the sinking liquid, the porous plate 13 is provided with a third through hole 14, in this embodiment, the porous plate 13 is provided with two, of course, in addition to two porous plates 13, it can also be three, four or more, the two porous plates 13 are spaced apart and staggered.

[0021] The second through holes 12 gradually decrease in spacing from the outside to the inside of the flow equalizing plate 10. The second through holes 12 of the flow equalizing plate 10 are arranged from sparse to dense from the outside to the inside.

[0022] The first through holes 11 gradually decrease in spacing from the outside to the inside of the distribution disc 9. The first through holes 11 of the distribution disc 9 are arranged from sparse to dense from the outside to the inside, and reduce the "dead zone" of the accumulated liquid.

[0023] The transition buffer zone 7 is provided with a condensing mechanism, which includes a condensing outer shell 15 provided with condensing channels 16 corresponding to and communicating with the first through holes 11 of the distribution disc 9, a condensing cavity arranged in the condensing outer shell 15, and an input pipe 17 and an output end 18 arranged on the condensing outer shell 15 and communicating with the condensing cavity. The condensing mechanism realizes condensation of liquid in the gas and reduces impurity interference.

[0024] The bottom of the separation tank 1 is provided with a supporting leg 19.

[0025] The working principle is that the external cooling medium is input through the input pipe 17, the cooling medium enters the condensing cavity of the condensing outer shell 15, and then is output through the output end 18, realizing cooling and heat exchange of the mixed liquid by the condensing mechanism; The water mixed liquid for hydrogen production by alkaline electrolysis is input into the upper part of the gravity settling zone 8 through the hydrogen-water mixed liquid inlet pipe 3, and the pressure in the cavity body 2 is stabilized at 0.1-0.6 MPa. According to the principle that the gas is above the liquid in the water mixed liquid, the liquid directly drops to the perforated plate 13, and the small gas bubbles remaining in the liquid are intercepted by the perforated plate 13 located below the hydrogen-water mixed liquid inlet pipe 3. After the small gas bubbles coalesce, the large gas bubbles continue to rise in the gravity settling zone 8. The intercepted liquid is guided to the reflux pipe 5 below the perforated plate 13 and then returns to the electrolytic tank for circulation. The residual amount of alkaline hydrogen gas after this process is controlled to be less than 0.2 g / L, ensuring that the outlet liquid meets the standard requirements. At the same time, the gas rises in the gravity settling zone 8 and carries a small part of the liquid. The gas passes through the first through holes 11 of the flow equalizing plate 10 arranged obliquely and enters the transition buffer zone 7. The flow equalizing plate 10 cuts the fluid to enhance turbulence and break the viscous binding of the alkaline solution to the small gas bubbles. The diameter of the small gas bubbles is less than 0.5 mm, which promotes the coalescence of the small gas bubbles into large gas bubbles. In this process, the collision probability of the gas bubbles increases, thereby improving the coalescence efficiency of the gas bubbles, promoting gas separation, and promoting the coalesced gas bubbles to rise along the "gas up" path, thereby improving the gas separation efficiency. Then, the gas passes through the condensing channels 16 of the condensing mechanism, condenses the water vapor in the gas, reduces impurity interference, and further improves the purity of the hydrogen gas. The condensing mechanism helps to reduce the water vapor in the gas, reduces the temperature of the gas, and ensures the output of pure hydrogen gas. The separated gas enters into the cyclone area 6 through the pipe distribution disc 9, and the cyclone area 6 is mainly gas cyclone. Because of the characteristics of the pipe distribution disc 9 that the middle is dense and the periphery is sparse, the gas generates a rotating flow field. A part of the liquid with large density moves to the outer wall under the action of centrifugal force, and the gas with small density gathers in the central area and rises to realize further gas-liquid separation. The alkaline electrolyte of the gas bubble enters the cyclone area 6 through the tangent inlet, and the inlet direction is tangent to the inner wall of the cyclone area 6, so that the fluid does high-speed circular motion along the inner wall of the cavity to form a rotating flow field. In the rotating process, the mixed liquid generates radial centrifugal force due to the circular motion, the liquid with large density moves to the outer wall under the action of centrifugal force, and the gas bubble with small density gathers in the central area and rises to realize further gas-liquid separation. The cavity structure of the cyclone area 6 can also strengthen the rotating flow speed, enlarge the centrifugal force effect, and improve the separation efficiency. The mixed liquid is subjected to the action of centrifugal force, the large gas bubble with a diameter greater than 1mm rises, and the gas and the liquid are gradually separated. The pipe distribution disc 9 effectively relieves the kinetic energy of the inlet gas, reduces the flow velocity impact and the turbulent flow phenomenon, ensures the uniform distribution of the fluid, and provides a stable flow field for subsequent cyclone separation. The separated hydrogen gas is discharged through the upper gas outlet pipe 4.

[0026] Based on the above ideal embodiments according to the present application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A multi-stage cyclone-gravity composite hydrogen-water separator for alkaline water electrolysis to produce hydrogen, characterized in that: The separation tank (1) includes a closed cavity (2) inside. The separation tank (1) is provided with a hydrogen-water mixture inlet pipe (3), an outlet pipe (4) and a return pipe (5) connected to the cavity (2). The cavity (2) is provided with a swirling zone (6), a transition buffer zone (7) and a gravity settling zone (8) arranged from top to bottom. The swirling zone (6) is used to make the mixture swirl and separate the gas and liquid. The transition buffer zone (7) is used to slow down the liquid flow speed and remove small bubbles remaining in the liquid. The gravity settling zone (8) is used to collect the settled liquid. The hydrogen-water mixture inlet pipe (3) and the return pipe (5) are both connected to the gravity settling zone (8). The hydrogen-water mixture inlet pipe (3) is located above the return pipe (5). The outlet pipe (4) is connected to the swirling zone (6).

2. The multi-stage cyclone-gravity composite hydrogen-water separator for alkaline water electrolysis hydrogen production according to claim 1, characterized in that: The cavity (2) is provided with a pipe tray (9) and a flow equalization plate (10) arranged from top to bottom. A swirling zone (6) is formed between the top of the pipe tray (9) and the cavity (2). A transition buffer zone (7) is formed between the pipe tray (9) and the flow equalization plate (10). A gravity settling zone (8) is formed between the bottom of the flow equalization plate (10) and the cavity (2). A number of first through holes (11) are evenly distributed on the pipe tray (9). The first through holes (11) connect the swirling zone (6) and the transition buffer zone (7). The flow equalization plate (10) is inclined and arranged in the cavity (2). A second through hole (12) is provided on the flow equalization plate (10). The second through hole (12) connects the transition buffer zone (7) and the gravity settling zone (8).

3. A multi-stage cyclone-gravity composite hydrogen-water separator for alkaline water electrolysis hydrogen production according to claim 2, characterized in that: The gravity settling zone (8) is equipped with a porous plate (13) for intercepting tiny air bubbles remaining in the sinking liquid.

4. A multi-stage cyclone-gravity composite hydrogen-water separator for alkaline water electrolysis to produce hydrogen according to claim 3, characterized in that: The perforated plate (13) is provided with a third through hole (14).

5. A multi-stage cyclone-gravity composite hydrogen-water separator for alkaline water electrolysis to produce hydrogen according to claim 4, characterized in that: Multiple perforated plates (13) are provided, and the multiple perforated plates (13) are spaced apart and staggered.

6. A multi-stage cyclone-gravity composite hydrogen-water separator for alkaline water electrolysis hydrogen production according to claim 2, characterized in that: The spacing between two adjacent second through holes (12) gradually decreases from the outside to the inside of the flow equalization plate (10).

7. A multi-stage cyclone-gravity composite hydrogen-water separator for alkaline water electrolysis hydrogen production according to claim 2, characterized in that: The spacing between two adjacent first through holes (11) gradually decreases from the outside to the inside of the tube tray (9).

8. A multi-stage cyclone-gravity composite hydrogen-water separator for alkaline water electrolysis hydrogen production according to any one of claims 2-6, characterized in that: The transition buffer zone (7) is equipped with a condensation mechanism for condensing liquid in the gas and reducing interference from impurities.

9. A multi-stage cyclone-gravity composite hydrogen-water separator for alkaline water electrolysis to produce hydrogen according to claim 8, characterized in that: The condensation mechanism includes a condensation shell (15), on which a condensation channel (16) is provided that corresponds to and communicates with the first through hole (11) on the pipe tray (9). A condensation chamber is provided inside the condensation shell (15). An input pipe (17) and an output end (18) are provided on the condensation shell (15). Both the input pipe (17) and the output end (18) are communicated with the condensation chamber.

10. A multi-stage cyclone-gravity composite hydrogen-water separator for alkaline water electrolysis to produce hydrogen according to claim 1, characterized in that: The bottom of the separation tank (1) is provided with support feet (19).

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