RU2327078C2 - Hydrogen vessel - Google Patents

Abstract

FIELD: mechanics, hydrogen power units.

SUBSTANCE: invention relates to hydrogen power units, hydrogen accumulation and storage. The vessel consists of a sealed casing, service branch pipes and a bundle of hollow capillaries arranged in the casing with their open ends brought into the hydrogen feed-release manifold, and a heater arranged in the said manifold. The capillary free ends arranged in the manifold are made narrowing. A free space of the manifold is filled to the heater with a sealant that features the hydrogen permeability factor at the vessel filling-emptying temperatures of up to (2.0-3.6)·10^-4 cm²/(s·atm^1/2), or with a material of lower melting or destruction temperature than that of capillaries. The invention aims at producing a vessel to keep hydrogen therein with higher safety, higher velocity and smoothness of hydrogen out flowing from the vessel to the User.

EFFECT: higher safety, higher velocity and smoothness of hydrogen out flowing from the vessel to the User.

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Description

The invention relates to the field of hydrogen energy - the accumulation and storage of hydrogen, which is currently used in chemical, transport engineering and other industries, as well as the accumulation of helium and other gases.

Known devices for the storage of hydrogen, based on the binding of hydrogen in a solid material (for example, in metal hydrides or sorption on the surface of dispersed nanomaterials), (RF patents Nos. 2037737, 2038525, IPC F17C 5/04), these devices for the storage and storage of hydrogen are the most explosion-proof of the existing ones, as hydrogen does not have excess pressure, but such systems are inertial and require a certain time (of the order of several minutes) to start work, the absorption and evolution of hydrogen occurs with significant thermal effects. In addition, the weight content of hydrogen — the ratio of the weight of hydrogen contained in the battery to the weight of the battery itself — 4.5% —is very low. The weight content depends both on the amount of hydrogen in the storage material and on the specific gravity of the storage material.

Known capacity for storing hydrogen (patent No. 2222749, IPC F17C 5/04), which is a sealed casing with an inner vessel for storing liquefied hydrogen, while the gas filling system is designed to reduce hydrogen loss, reduce the time of filling the tank. Capacity for a hydrogen car (Schwartz A. Car of the future. - Bulletin, 05/12/2004, No. 10 (347), pp. 1-5), made of durable composite relatively light materials. The last modification with pressure cylinders has a volume of 90 liters, a mass of 40 kg, a hydrogen pressure of 400 atm. Estimates show that in this case 3.2 kg of hydrogen can be stored in the tank, therefore, the weight content of hydrogen is 3.2 / 40 × 100% = 8%. The disadvantages of the tank are explosiveness and low hydrogen content per unit volume, up to 400 liters of hydrogen per 1 liter.

It is known that hydrogen can be stored in hollow capillary fibers made of glass (Yan KL, Sellars BG, Lo I. et al. Storage of hydrogen by high pressure microencapsulation in glass // Intern. J. Hydrogen. Energy. 1985. Vol .10, N18. P.517-522). Hollow capillaries with a length of 15 cm, a diameter of 160-260 microns, and a shell thickness of 16-35 microns were sealed on both sides. Then the capillaries were placed in a volume where a hydrogen pressure of 700 atm was created and when heated to 300 ° C, the inner cavity of the capillaries was saturated with hydrogen. After cooling, hydrogen remained inside the capillaries, and when heated out. Such a system is explosion proof, but the weight content of hydrogen in such a system is 4.2%. This hydrogen content is very low to create industrially applicable hydrogen storage tanks. In addition, the filling and extraction of hydrogen must be carried out at temperatures of 300 ° C and above. At the same time, refueling and hydrogen recovery proceeds slowly and lasts several hours, while the time requirements for refueling containers are 4-10 minutes.

The prototype of the invention is a container for storing hydrogen (A.F. Chabak. Hydrogen accumulators based on ordered microporous structures. - Science and technology in industry, 2006, No. 1, p.24-27).

The capacity is a sealed enclosure with technological pipes - hydrogen supply and exhaust, installation of a safety valve. In the housing there is a bundle of hollow capillaries, the open ends of which are brought into the hydrogen supply and exhaust manifold, and a heater. The advantages of the tank are a high specific gravity of hydrogen in the capillaries and high explosion safety. But a significant drawback of the tank is the slow process of extracting gas from the closed volumes of capillaries, since the extraction of gas is carried out due to the process of gas diffusion at elevated temperatures. Such containers do not meet the requirements for gas supply to the consumer. In the case of a diffusion mechanism, the gas extraction rate is proportional to the surface area through which gas diffusion is carried out, and is also determined by the temperature of this surface. Therefore, to improve the extraction of gas from capillaries, it is necessary to heat the entire structure, which requires large energy costs and such a gas extraction technology may prove to be energetically disadvantageous.

The technical result, which the invention is directed to, is the creation of a tank for storing hydrogen, providing high reliability, speed and smoothness of the flow of hydrogen to the consumer.

To achieve this result, a hydrogen storage tank is proposed, consisting of a sealed housing, process pipes and hollow capillaries placed in the beam body, the open ends of which are brought into the hydrogen supply and exhaust manifold, and a heater located in the collector, while the open ends of the capillaries located in the collector, tapering, the free space of the collector to the heater is filled with a sealing material with high permeability to hydrogen or at a lower rate melting point or with a temperature of destruction than the melting point of the material of the capillaries.

In addition, the tapered ends of the capillaries are made cone-shaped with flat end surfaces.

In addition, the tapered ends of the capillaries are made with spherical end surfaces.

The tapering part of the capillaries can be made with a coating of metal, or polymer, or glass.

Capillaries can be made of glass, or carbon, or metal, or polymeric materials, or their compositions, for example glassy carbon.

The high hydrogen permeability sealant is palladium or nickel based alloys, or graphite or glass based compositions, or polymeric materials.

The low melting sealant material is glass, or a metal alloy, or a polymeric material.

The low temperature degradation sealant is a polymeric material or an organometallic compound.

Figure 1 presents a schematic diagram of the implementation of the capacity for storing hydrogen, figure 2 and 3 show the bundles of capillaries. Figure 4 presents a photograph of individual capillaries with an outer diameter of 525 μm with sphere-shaped ends of the tapered ends of the capillaries.

Designations of positions in the figures:

1 - housing;

2 - a collector for supplying and discharging hydrogen;

3 - pipe supply gas to the consumer;

4 - capillaries;

5 - tapering ends of the capillaries;

6 - sealing material;

7 - heater;

8 - housing cover;

9 - pipe for installing a safety valve;

10 - a partition for fixing the sealing material;

11 - pipe for installing a pressure sensor;

12 - shell.

The tank consists of a sealed housing 1 with located in the upper part of the housing at the level of the hydrogen supply-exhaust manifold 2, a gas supply-output pipe 3 and pipes 9 and 11 for installing a safety valve and a pressure sensor, respectively. The housing may be made in the form of a cylindrical container, as shown in figure 1. A heater 7 is installed in the collector of the supply and exhaust of hydrogen 2. The heater can be made sectional and installed in the collector 2 above the bunch of capillaries. A bundle of hollow capillaries 4 is inserted inside the housing 1 through the lid 8. The ends of the capillaries 5 are located in the hydrogen supply and exhaust manifold and are made tapering. The entire space between the partition 10, which separates the collector from the space of the housing in which the capillary beam is located, and the heater 7 is filled with a sealing material 6. This material is, for example, granules of a material with a melting or degradation temperature lower than the melting temperature of the material from which capillaries are made.

The device operates as follows.

The container is placed in a pressure vessel (not shown). The pipe for supplying hydrogen to the consumer 3 is open. The pressure vessel is evacuated, then filled with hydrogen to high pressure. Depending on the type of battery (for a car, portable power supplies for computers, telephones, etc.), the hydrogen pressure in the battery for each type may vary, but it should usually be more than 500 atm. Hydrogen from the pressure vessel through the pipe 3 through the holes in the ends of the tapered ends 5 of the capillaries enters the capillaries 4. After creating the necessary pressure in the capillaries, the heater 7 is turned on, which is, for example, a multi-section induction heater, a high-frequency radiation source, etc. The material 6 melts and closes the holes in the tapered ends of the capillaries. Then the heater is turned off, the material 6 solidifies, hydrogen under pressure is inside the capillaries. After cooling, the gas pressure in the pressure vessel decreases to the required level, the nozzle 3 is closed, the gas from the pressure vessel is discharged, followed by its evacuation. Hydrogen parameters are monitored and regulated by a safety valve and a pressure sensor installed in pipes 9 and 11, respectively.

To extract hydrogen from the capillaries, the container is connected through the pipe 3 to the consumer, when the hydrogen pressure in the collector 2 is lowered, which is controlled by the pressure sensor, one or more sections of the multi-section heater 7 are turned on, in the heating zone the sealing material 6 heats up, becomes viscous and high-pressure gas from capillaries in the heating zone, destroying the viscous layer, enters the collector 2. After the consumer has consumed this portion of gas, the following sections of the multi-section heater are turned on. The process is periodically repeated until the gas is completely extracted from the capillaries, after which the next refueling of the battery occurs.

Material 6 performs at least two main functions: firstly, it seals or opens the holes connecting the internal volume of the capillaries to the collector, and secondly, it increases the strength characteristics of the tapered ends of the capillaries. Filling material 6 of the space between the ends of the capillaries allows you to compensate for additional stresses that may appear due to inaccuracies in the manufacture of tapering ends of the capillaries. The execution of the ends of the capillaries with a changing geometry - tapering, allows to improve the adhesion of the sealing material with the material of the capillaries due to the increase in the adhesion surface of these materials compared to the version when the ends of the capillaries without changing the geometry go into the collector.

The high hydrogen permeability sealant can be made of palladium alloys (an alloy of palladium with silver) or nickel, or polymeric materials, for example, aromatic polyamides. It is also possible to use compositions based on graphite or glass with special additives, for example, magnetite. The hydrogen permeability coefficient for such materials at operating temperatures at which charging and discharging of a tank of 100-250 ° occurs is up to (2.0-3.6) 10 ^-4 cm ² / (s · at ^1/2 ).

The sealing material with a melting point lower than the melting point of the capillary material may be glass, a metal alloy, a Wood alloy, or a Devard alloy, or a bismuth alloy; or lead or tin; or polymeric materials (melting points are in the range of 40-800 °) and in the form of granular material or plates are placed in the collector 2 to the level of heater 6.

The sealing material with a temperature of destruction lower than the melting temperature of the material of the capillaries can be carbocyclic compounds of the type C ₁₀ H ₈ - naphthalene group (melting point - 80.3 ° C, boiling point 218 ° C), polyethylene, which become plastic when they heating to a temperature of ~ 80-200 ° C. They are also in the form of granular material are placed in the collector 2 to the level of the heater 6.

The tapered ends of the capillaries can be made conical, as shown in FIGS. 1 and 3, with flat end surfaces or with spherical end surfaces, as shown in FIG.

In this case, the capillary beam can be made in the form of individual capillaries parallel to the axis of the vessel (Fig. 1), or in the form of capillaries wound around the axis of the vessel, or a simultaneous combination of these two options, for example, capillaries are wound around the periphery of the body and capillaries parallel to the axis are placed inside corps. Capillaries can be assembled into matrices surrounded by a sheath 12, as shown in FIGS. 2 and 3. Other options are possible.

Both ends of the capillary structures or one can be output to the collector 2, in the latter case, the second end is sealed (welded, etc.). The capillaries are made of glass, or carbon, or metal, or polymeric materials, or compositions based on these materials, for example glassy carbon.

A coating may be applied to the surface of the capillaries to reduce the diffusion flow of hydrogen through the side surface. Coating the surface of the tapering parts of the capillaries 5 makes it possible to improve the adhesion of this surface to the sealing material. For example, applying a copper coating to quartz capillaries allows the use of metals with a lower melting point as a sealing material, while without such a coating, glasses with a melting point lower than quartz can be used as a sealing material. The coating can be made of metal, polymer, glass.

Examples

Example 1. A matrix was created from quartz capillaries, the length and width of the matrix were 5.3 mm, and the height was 50 mm. The outer diameter of the capillaries is 530 microns, the inner is 490 microns, and the shell thickness is 20 microns. The appearance of the capillaries from which the matrix was created is shown in FIG. 3. The lower ends of the capillaries are hermetically sealed. In the center of the upper conical ends of the hole with a diameter of 20 microns. Capillaries are welded (sintered) into a matrix.

The shell around the matrix is made of quartz and only near the upper ends. Sheath height 6 mm. The height of the shell is distributed as follows: 3 mm of the shell is located on the cylindrical part of the capillaries, 1.0-1.5 on the conical part of the capillaries and 1.5-2.0 above the ends of the conical part of the capillaries. Finely dispersed glass powder with a melting point of 650 ° C (a melting point of quartz of 1600 ° C) was poured into the upper volume of the shell where the conical part of the capillaries and above was poured. The matrix was weighed with powder from glass. Weight - 517 mg.

The matrix was placed in an autoclave with a heater. A hydrogen pressure of 1000 atm was created in the autoclave and the matrix was filled with hydrogen. Then, in the zone of the upper end of the matrix, the heater was turned on, heating was carried out to a temperature of 700 ° C, and at this temperature, heating continued for 15 minutes. Then the heater was turned off, the autoclave was cooled, the pressure in the autoclave was released, and the weight of the matrix was determined. The weight of the matrix with hydrogen is 565 mg. The weight of hydrogen (565-517) = 48 mg. This corresponds to 9% by weight of hydrogen in the matrix.

Example 2. A matrix is created from similar capillaries with the same dimensions. This matrix differs in that the upper ends are spherical with holes of 20 μm in the center of the axis of the capillaries, as shown in figure 4. A copper coating 20 microns thick is applied to the upper ends. A bismuth-based alloy foil was applied to the surface of the ends; the foil thickness was 100 μm. Matrix and foil were weighed. Total weight - 468 mg. The matrix with foil at the spherical ends was placed in an autoclave. A hydrogen pressure was created in an autoclave of 1000 atm. The capillaries were filled with hydrogen. Then the heater was turned on in the region of the spherical ends with foil. A temperature of 300 ° C was maintained at which the foil melted. The heater turned off. The bismuth alloy cooled and sealed the capillaries. After pressure reduction and evacuation, the matrix was removed from the autoclave and weighed. The weight of the matrix with hydrogen was 515 mg. The weight of hydrogen is 47 mg. This corresponds to 10% by weight of hydrogen in the matrix.

Thus, the proposed design of a hydrogen storage tank ensures safe storage of hydrogen, high speed and adjustable supply of hydrogen to the consumer, which significantly expands the functionality of its use, such tanks can be used as hydrogen batteries for cars, portable power supplies for computers, phones, etc. d.

Claims (8)

1. A hydrogen storage tank, consisting of a sealed housing, process pipes and hollow capillaries located in the beam housing, the open ends of which are brought into the hydrogen supply and exhaust manifold, and a heater located in the collector, characterized in that the open ends of the capillaries located in the collector is made tapering, while the free space of the collector to the heater is filled with a sealing material with a coefficient of permeability to hydrogen at temperatures at which the charge Dka-discharge capacity to (2.0-3.6) · 10 ^-4 cm ² / (s · at ^1/2 ), or material with a lower melting point or with a temperature of destruction than the melting temperature of the material of the capillaries. 2. The container according to claim 1, characterized in that the tapering ends of the capillaries are made conical with flat end surfaces. 3. The container according to claim 1, characterized in that the tapering ends of the capillaries are made with spherical end surfaces. 4. The container according to claim 1, characterized in that the tapering ends of the capillaries are made of a coating of metal, or polymer, or glass. 5. The container according to claim 1, characterized in that the capillaries are made of glass, or carbon, or metal, or polymeric materials, or compositions based on these materials, for example, glassy carbon. 6. The container according to claim 1, characterized in that the sealing material with high permeability to hydrogen is an alloy based on palladium or nickel, or a composition based on graphite or glass, or polymeric materials. 7. The container according to claim 1, characterized in that the sealing material with a low melting point is a glass, or an alloy of metals, or polymeric materials. 8. The container according to claim 1, characterized in that the material with a low temperature of destruction is a polymer material or organometallic compounds.

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