RU2178113C2 - Multispace reservoir for transportation and storage of compressed gases - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: invention can be used in manufacture and operation of high- pressure reservoirs and cylinders for transportation of compressed gases from gas fields to consumers, manufacture and operation of storages, fuel tanks of vehicles, fuel and shielding gas containers of gas welding and cutting equipment, cylinders with air-oxygen mixture for breathing apparatuses, etc. Proposed multispace reservoir has closed spherical, cylindrical, conical or combination communicating containers nested on into the other and installed with clearance for keeping gas under pressure in space between container walls. Envelopes of containers are reliably interconnected by common flange- collector in which gas channels of closed spaces are united. Strips of container envelopes opposite to flange-collector form combined space being movably connected in axial direction by centering trunnions which additionally increase strength and reliability of reservoir. Distributing shutoff-and-safety device of reservoir has housing, shutoff valve, compressed gas inlet and outlet unions, distributing spool with profile and radial communicating channels. Longitudinal blind channel is connected with at l3east one radial channel aligning with corresponding gas outlet channel, when spool is moved under action of compressed gas, to direct gas into corresponding space of multispace reservoir. Flexible element is installed in axial direction of spool movement from side opposite to gas inlet to end face pressure chamber. Flexible element is separated from spool by sealing separating diaphragm. Safety valve is installed in channel along which gas is passed into reservoir space. In large- size multispace reservoirs consisting of three and more spaces, each space can be furnished with separate independently adjustable control spool, and distributing shutoff-and-safety device can be made in form of separately mounted unit. EFFECT: increased gas holding capacity at reduced overall dimensions and mass, simplified system of compressed air take-off by consumers. 4 cl, 7 dwg

Description

 The invention relates to the field of engineering and can be used in the manufacture and operation of reservoirs and high-pressure cylinders for transporting and storing compressed gases, including two transporting gases from a field to a consumer, fuel tanks of vehicles, combustible and shielding gases, as welding tanks cutting equipment, cylinders with air-oxygen mixtures for breathing equipment, etc.

 Considering the high requirements for reliability and safety during operation, gas cylinders are currently made monolithic without welding or with limited use only for welding the blank bottom of the cylinder (see Industry standard catalog of the USSR MFM "Pipes and pipe products. Small and medium-sized cylinders" . M., 1985, p. 14 and 27). Monolithic thick-walled cylinders of low-strength carbon or low alloy steel have a large mass and limit the ability to effectively use heavy cylinders in automobile transport or in portable equipment - medical, oxygen-insulating breathing apparatus, gas cutting equipment, etc., since they exclude the possibility of increasing the useful capacity by increasing the overall dimensions and increasing the internal pressure of the compressed gas.

 Thus, the relief of high-pressure cylinders with a simultaneous increase in their capacity by increasing the internal pressure of the compressed gas can be achieved only through the use of high-strength materials and composite materials, as well as through the search for new design and technological solutions.

 Lightweight high-pressure cylinders are known, the mass reduction of which is achieved through the use of high-strength materials (see V. M. Trushin. "Gas equipment and apparatus for gas-balloon vehicles", ed. "Nedra", L. 1990, (p. 53), consisting of a thin-walled inner shell, bottoms with welded fittings and a reinforcing braid on the outer surface of fiberglass or other polymeric materials.The disadvantage of such cylinders is the inability to increase the volume and pressure of the compressed gas without increasing the overall dimensions and mass of the ba the womb.

 Another high-pressure balloon is known (see a.s. USSR 313024, 1971), consisting of an inner cylindrical shell with bottoms and a fitting and an outer reinforcing braid of high-strength wire. Such a cylinder has the above disadvantages.

 A pressure vessel is also known (see A.S. USSR 1195124, 1985), containing an internal airtight shell concentrically installed in the outer shell with a gap, and the gap is filled with a component, for example concrete, reinforcing (reinforcing) the inner shell. The disadvantage of such a vessel is the limited possibility of its use mainly in stationary systems of large capacity and low specific capacity (the ratio of usable volume to the volume of the external dimension of the vessel).

 A pressure vessel is known (see a.s. USSR 1067289, F 17 C 1/00, publ. 15.01.84), containing coaxial shells that form cavities between each other with pressure decreasing from the center to the periphery and connected through a safety valve with the atmosphere, and each inner cavity is connected to its outer cavity through a safety valve. The disadvantage of this design is that the difference in internal pressures in the coaxial shells of the vessel requires the use of separate compressors for separate filling of each cavity.

 Other well-known technical solutions (for example, US patent 2131753, NKI 23-29, 1938 and 3830259, NKI 138-80, 1974 g, UK patent 1230903, NKI BIX, 1969 g, Germany patent 1559150, MKI E 04 H 7/00, 1975 and others) have the disadvantages of the analogues discussed above and do not provide an effective increase in the capacity of compressed gas due to an increase in internal pressure.

 A known tank for transporting and storing natural hardly liquefied gases (see RF patent 2035004, F 17 C 1/00, publ. 05/10/95), including closed containers coaxially inserted into one another, installed with a gap for placing gas under pressure between the walls of the containers, and each subsequent tank is connected with the previous pipeline through the compressor with a constant compression ratio of two, and is equipped with a safety valve.

 Such a multi-cavity tank provides the possibility of a sharp increase of 2.5-3 times the volume of injected gas compared to a single-cavity tank while maintaining the same physical (external dimensions) volume, but has a complex filling and reduction system.

 A consumable-filling device for filling reservoirs and cylinders with compressed air is known (see the book by G. Grigoriev et al. "Gas tanks", M., Mashinostroenie, 1989, p. 164-182), including a shut-off filling-flow valve and a safety valve ensuring the connection of the tank to the injection compressor of the gas filling station (CNG filling station), while the filling valve eliminates the possibility of increasing the pressure in the cylinder above the limit values and locking the cylinder after filling it with compressed gas.

 The disadvantage of this device is the impossibility of a stepwise filling of each of the separate cavities of the multi-cavity tank to a certain design pressure from the compressor of the gas filling station.

 Another valve device is known (see A.S. USSR 1451395, F 16 K 17/01, 1989), comprising a housing with channels made therein from high and low pressure pumps with two drain channels and shut-off elements separating the channels, moreover, the locking element separating the pressure channel from the high pressure pump and the first drain channel is made of spool and installed coaxially with the loaded spring towards the closing side, the locking element disconnecting the channel from the low pressure pump with the second drain channel, the cavity of the housing under the spool om the side opposite the locking element uncoupling flow channel of the low pressure pump and a drain conduit, a throttle opening communicated to the discharge channel from the high-pressure pump communicating with the intake passage.

 The disadvantage of such a valve device is the need to use a separate compressor for each gas pressure level in a particular cavity of a multi-cavity container.

 A device is also known for filling a multi-cavity tank with compressed gas with a stepwise increase in pressure in each internal cavity relative to the external pressure (see RF patent 2035004, F 17 С 1/00, publ. 05/10/1995), including one coaxially inserted into another closed tank installed with a gap for placing gas under pressure between the walls of the tanks, with each inner tank communicating with the previous pipeline through a compressor that provides a constant compression ratio of two, and provided with a safety Yelnia valve.

 The disadvantages of this device is the need to use additional booster compressors between each pair of adjacent cavities.

 Known valve gear (see application France 2574896, F 16 K 25/00, G 05 D 16/10, publ. 06/20/86,), consisting of a main and control valves, each of which is equipped with a piston for actuating the valve, and the piston contains an inner movable element defining the outer cylindrical surface, and an outer element defining the inner cylindrical surface opposite the specified outer surface of the inner element, while the inner element has at least two annular grooves made on the outer surface surface and offset along the axis relative to each other, in which there are installed sealing fluoroplastic split rings.

 The disadvantages of this pressure reducing valve are its structural complexity and the inability to use it for stepwise regulation of the pressure of the compressed gas in each separate cavity of a multi-cavity cylinder when filling and controlled consumption of compressed gas from a multi-cavity cylinder, a spool valve (see RF patent 2008528, F 15 V 13 / 042, published on 08.19.87), comprising a housing with elements for supplying and discharging a working medium and a cylindrical axial bore axially mounted therein with the possibility of axial movement spool with longitudinal and radial valves communicated with each other, seal rings, separating the working medium supply and removal channels.

 The disadvantages of all the switchgears considered are their structural complexity, the limited ability of multi-compressor systems or the inability to use the known control valves and gearbox valves for the stepwise filling of each of the separation cavities of one compressor of a gas filling station.

 The closest analogue is a tank for transporting and storing compressed gas, which includes two shells connected by mouths interconnected, nested one into the other, and a distribution control device in which the spool is placed in the inner cylindrical bore (RF patent 2067256, class F 17 C 1 / 00, publ. 09/27/96).

 However, the drawback of this reservoir and the general drawback of all the analogues considered are the limited ability to use only for large tanks and the need to use separate intermediate compressors when filling, as well as the complexity of the reduction system when consuming gas from tanks connected in series with different pressure levels. In addition, the use of booster intermediate compressors with a double increase in pressure in each inner shell leads to the need for a sharp increase in wall thickness.

 The aim of the present invention is to develop designs of a multi-cavity tank and its distribution locking and safety device for controlled stepwise filling with compressed gas of each of the separate cavities of a multi-cavity tank to various levels of design pressures from a single compressor of a gas filling station or during unpressurized charging from a single compressed gas accumulator with a nominal pressure and subsequent controlled selection of compressed gas by the consumer from the multi-cavity ezervuara.

 This goal is achieved in that the reservoir for transporting and storing compressed gases "PRETTI", containing at least two shells connected by a flange-collector, interconnected, inserted into each other with a gap, forming cavities for accommodating compressed gas, and a distribution control the device, in the inner cylindrical bore of which is placed a spool with an axial channel and radial holes communicating with the internal cavities of the shells, an elastic element, characterized in that the multi-cavity tank and the distribution control device are made in the form of separate mating elements, while the common connecting flange-collector seals and communicates the channels of the gas cavities with the corresponding channels of the distribution control device, the opposite poles of the shells forming the joint cavity, are axially movably connected by centering trunnions, and the distribution control device is made in the form of a housing, additionally equipped with safety valves are constantly communicated with each of the internal cavities and are configured on their limiting pressure shut-off valve and fill-consumable fitting external gas system.

 An additional increase in the mechanical bond strength of the shells in a multi-cavity tank is achieved by the fact that the poles of the shells of the containers, which form a joint cavity, opposite to the common connecting flange-collector, are axially movably connected by centering pins.

 In addition, an additional increase in the relative parameters “volume-pressure-mass” and optimization of the layout are achieved by the joint use of closed shells that differ in shape, for example, spherical, cylindrical, conical or complex configuration.

 At the same time, the channels for discharging compressed gas from the control valve are combined in a connecting fitting-manifold, which ensures that, when a distributing locking and safety device is installed in the connecting flange-collector of a multi-cavity reservoir, its connections with its respective cavities.

 In addition, for large multi-cavity reservoirs and reservoirs containing three or more cavities, each cavity can be equipped with a separate control valve, independently adjusted for the corresponding design pressure, and the distribution locking and safety device is made in the form of a separately installed remote unit.

 The invention is illustrated by drawings (Fig. 1-7).

 FIG. 1 - general view (in section) of a cylindrical multi-cavity (3-cavity) tank: 1 - outer cylindrical shell; 2 - a cylindrical middle shell; 3 - inner cylindrical shell; 4 - connecting flange-collector.

 FIG. 2 - general view (in section) of a spherical multi-cavity (3-cavity) reservoir: 4 - connecting flange-collector; 5 - outer spherical shell; 6 - spherical middle shell; 7 - inner spherical shell; 8 - centering pins.

 FIG. 3 - a general view (in section) of a distribution locking and safety device of a three-cavity tank: 9 - a housing; 10 - filling consumable fitting; 11 - shutoff valve; 12 - regulatory spool; 13 - elastic spring element; 14 - a separation membrane; 15 - safety valve (indicated in Fig. 4 and 5); 16 - connecting fitting-collector; 17 - a connecting nut; 18 - a basic ring; 19 - sealing elements; 20 - axial blind channel spool; 21 is a channel for discharging gas into the outer cavity of the tank; 22 - channel for the removal of gas into the cavity; 23 - channel for the removal of gas into the internal cavity.

 FIG. 4 is a general view (in section along A-A) of a three-span distribution locking and safety device for 4-7-cavity tanks.

 FIG. 5 is a general view (in section along BB, BB) of the safety valve in the gas exhaust channel into the reservoir cavity.

 FIG. 6 is a general view (in section) of a multi-cavity (three-cavity) reservoir for transporting and storing compressed gases and its distribution locking and safety device in an assembly: 24 — an external cavity; 25 - cavity; 26 - internal cavity.

 FIG. 7 - a general view (in section) of a distributing locking and safety device made in the form of a separate remote unit connected by pipelines to a multi-cavity tank: 27 - a separate remote block of RPZPU: 28 - a multi-strip tank (3-cavity); 29 - the middle cylindrical shell; 30 - inner conical shell; 31 - pipeline channel reduced pressure; 32 - pipeline medium pressure channel; 33 - pipeline channel high pressure.

 A multi-cavity tank, for example a 3-cavity cylindrical (Fig. 1), includes an outer cylindrical shell (1), a middle cylindrical shell (2) and an inner cylindrical shell (3), firmly fastened by a connecting flange-collector (4), combining gas closed cavity channels for accommodating compressed gas.

 A similar design (Fig. 2) is a spherical multi-cavity (3-cavity) reservoir, which includes a spherical outer shell (5), a spherical middle shell (6) and a spherical inner shell (7), firmly fastened by a common connecting flange-collector (4) , combining the gas channels of closed cavities to accommodate compressed gas, and additionally increasing the mechanical bond strength of the shells in a multi-cavity tank, especially when inertial loads occur, is achieved by installing in opposite boiling common-collector connecting flange (4) poles shells forming the joint cavity, centering pins (8), compounds having a mobility in the axial direction. A multi-cavity tank may be made of complex shells.

 A multi-cavity tank operates only in conjunction with its distribution locking and safety device.

 Distribution locking and safety device (RZPU) (Fig. 3) includes a housing (9) with a filling consumable fitting (10), a shut-off valve (11), a control spool (12), an elastic spring element (13), a separation membrane ( 14), a safety valve (15), a connecting fitting-collector (16), a connecting nut (17), a support ring (18) and sealing elements (19).

 Distribution locking and safety device operates only in a joint assembly with a multi-cavity tank.

 The operation of a multi-cavity reservoir for transporting and storing compressed gases and its distributive locking and safety device PRETTI in a joint assembly is considered in examples 1 and 2.

 Example 1 (Fig. 6).

 Preparing the tank for work. Preparation of a multi-cavity tank for operation is as follows. In the connecting flange-collector (4) of the tank (see Fig. 1), a connecting fitting-collector (16) of the distribution locking and safety device (see Fig. 3) is installed and the connection is sealed with sealing elements (19) by pinching them with a nut (17 ) through the support ring (18). At the same time, the gas removal channels (21, 22 and 23) are connected from the RPZU to the corresponding cavities (24, 25 and 26) of the reservoir (see Fig. 6) and the reservoir is ready for operation.

 Refueling (filling) the tank. The filling and consumable nozzle (10) of the RZPU is connected to the compressed gas supply system from the CNG filling station or the compressed gas accumulator, the shut-off valve (11) is opened and the compressed gas flows through the axial blind channel of the tap (21, 22 and 23) to the external ( 24), middle (25) and internal (26) cavities. As the reservoir fills, the pressure in the cavities and in the pressure spool chamber increases, under the action of which the spool (12) begins to move, compressing the elastic element (13). In this case, the positional position of the radial channels of the spool (12) changes and, upon reaching the pressure level corresponding to the design pressure in the outer cavity (24), the movement of the spool, controlled by the adjustment of the elastic element (13), must reach the position at which the gas outlet channel is cut off 21) into the outer cavity. Moreover, if the pressure value of the compressed gas exceeds the calculated value for the external cavity, then the excess gas pressure is released through the safety valve (15) in the channel (21) and makes adjustment (weakening) of the elastic element (13), and the further flow of compressed gas occurs only into the middle (25) and internal (26) cavities with a corresponding increase in pressure.

 Upon reaching the pressure corresponding to the calculated pressure in the middle cavity (25), the gas exhaust channel (22) is cut off and further compressed gas flows through the exhaust channel (23) only into the internal cavity (26) and is filled to the calculated pressure, and then the shut-off valve (11) closes and the filling-consumable fitting (10) is disconnected from the CNG filling station or compressed gas accumulator.

 Given that the stroke of the spool (12) is adjusted by the elastic element (13) according to the calculated pressure of the compressed gas in the outer cavity (24), the cut-off time of the gas exhaust channel (22) is determined by the calculated position of the corresponding radial channel of the spool and the width of its outer groove, experimentally specified for each size of the distribution locking and safety device and tank.

 The simplification of the setup process RPM can be achieved through the use of a separate regulatory spool unit for each cavity and an increase in the number of regulatory spools (2-3 spool) in one REPU (see Fig. 4).

 Discharging (emptying) the tank.

 The filling and consumable fitting (10) of the RZPU is connected to the reducer of the gas consumption system, the shut-off valve (11) opens and gas is compressed from the tank to the consumer. In this case, the gas flow occurs in the reverse order of the filling process, i.e., the gas is consumed first from the internal cavity (26) and after the pressure equalizes to the pressure level in the middle cavity (25), the gas flow comes from both (26 and 25) cavities, and when the gas pressure in them decreases to the pressure level in the outer cavity (24), it is connected and further gas consumption goes immediately from all 3 cavities until the tank is completely empty. After emptying the tank, the shut-off valve (11) is closed, the filling-consumable fitting (10) is disconnected from the consumption system and the tank is returned to the CNG filling station for refueling (filling).

 Example 2 (Fig. 7).

 Preparing the tank for work. Preparation for operation of a multi-cavity reservoir (28) with a PRETTI distribution locking and safety device, made in the form of a separate remote unit (27), is carried out as follows.

 The fittings of the connecting flange-collector (4) are connected by high pressure pipelines (31, 32 and 33) with the corresponding fittings of the remote relay control unit (27) and the tank is ready for operation.

 Refueling (filling) the tank. The filling and consumable nozzle (10) of the RZPU is connected to the compressed gas supply system from the CNG filling station or compressed gas accumulator, the shut-off valve (11) is opened and the compressed gas is supplied through the axial blind channel (20) of the spool (12) and the exhaust channels enter the same pressure simultaneously into outer (24), middle (25) and inner (26) cavities.

 The further stages of the processes of filling and emptying the cavities of the tank and the mechanism of operation of the RZPU described above in example 1.

The use of the proposed designs of the multi-cavity tank for transportation and storage of compressed gases and its distribution locking and safety device provide:
- the possibility of creating reservoirs of increased gas capacity while reducing their overall dimensions and reduced weight;
- simplification of the design of multi-cavity tanks with the possibility of varying the simultaneous use of shells of various types of shapes - sphere, cylinder, cone, complex configuration and combinations thereof;
- simplification of the design of the distribution locking and safety device, providing a given pattern of multi-stage distribution of compressed gas when filling at levels to the design pressure in the cavities;
- increasing the efficiency of the process of executing multi-cavity tanks with different levels of gas pressure in the cavities from the compressor unit or when the compressor is uncharged from a gas accumulator with a single-stage gas compression system for a nominal maximum charging pressure, for example, equal to 32 MPa;
- simplification of the system of controlled selection of compressed gas by the consumer from a multi-cavity tank;
- increasing the economic efficiency of using compressed natural gas as a fuel by expanding a number of its potential consumers (automobile and water transport, various industries), as well as systems for transporting compressed gas from fields to consumers.

Claims (4)

 1. A multi-cavity tank for transporting and storing compressed gas, including at least two shells connected by a collector flange, interconnected shells, inserted one into the other with a gap, forming cavities for accommodating compressed gas, and a distribution control device in the inner cylindrical bore which spool is placed with an axial channel and radial holes communicating with the internal cavities of the shells, an elastic element, characterized in that the reservoir is multi-cavity and distributive e control device is made in the form of separate mating elements, while the common connecting flange-collector seals and communicates the channels of gas cavities with the corresponding channels of the distributing control device, the opposite poles of the shells forming the joint cavity are movably axially connected by centering pins, and distribution control device is made in the form of a housing additionally equipped with safety valves, constantly with communicated with each of the internal cavities and tuned to their ultimate pressure, a shut-off valve and a filling and flow nozzle of the external gas system.  2. The tank according to claim 1, characterized in that the shells of the containers are made in the form of a sphere, cylinder, cone, and combinations thereof.  3. The tank under item 1 or 2, characterized in that each gas cavity is equipped with a separate independent regulating spool device.  4. The tank according to any one of paragraphs. 1-3, characterized in that the distribution regulating locking and safety device is made in the form of a separate remote unit.

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