DE1433272A1 - Process and container for the underground storage of liquid gas at a very low temperature - Google Patents

Description

Method and container for underground storage of liquid gas at a very low temperature

The storage of liquid gas at a very low temperature, such as liquid oxygen, liquid methane or the like, first requires the selection of the pressure under which the storage container is to be operated. In the plants, on the ground or on ships, storage under atmospheric pressure will usually be carried out while the liquefied gas is being drawn off by pumping. In the case of underground storage in a suitably arranged cave, it is possible to make use of the advantages that result from operating under pressure. The operation of a storage between the atmospheric pressure and a pressure of k kg per cm completely avoids a gaseous state during the withdrawal _o

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but green pumps required. to perform the trigger If you set up the container in such a way that the operation

For example, if the pressure is between 3 and 6 kg per cm, pumps can be dispensed with in order to pull through To realize a siphon pump · Here one lets the liquid rise to the surface due to the effect of the pressure on the liquid level. This pressure is obtained if necessary by injecting gas under pressure in the gaseous state in the upper part of the container

The advantages of this last mode of operation are great: In the future it will be possible to use all mechanical devices to eliminate in the bottom of the container; one completely avoids the gas phase of the fume cupboard; one no longer sits down the danger posed by the concentration of impurities or heavier substances in the liquid phaseOn the other hand, the evaporation ratio is reduced, because the temperature of the subterranean liquid is higher than the temperature of the injected liquid

In the case of storage of natural liquefied petroleum gas, it is necessary to store it underground to be realized under a pressure that must be as great as possible. This pressure is practically only due to the ground pressure limited, which prevails above the underground outer cavity for the storage of the gas liquid · The natural liquid gas comes mainly from methane ships and has almost

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a boiling temperature corresponding to the atmospheric pressure While it is being stored in the underground container, the natural liquid gas receives heat from the gas surrounding the container Soil · This results in an increase in temperature and pressure of the liquid and the stored gas · Due to the evaporation results for one and the same system a constant amount of gas at low pressure and is in a container under high pressure by an increase in pressure and the temperature translated

The construction, the first filling and the

Operation of an underground container for the storage of Liquid gas at very low temperature under pressure present a number of problems. The present invention has essentially an underground storage container under pressure for liquefied gas at a very low temperature, and relates in particular to its manufacture, its construction and the first filling

The invention is particularly characterized

in that after pipes have been installed for operation, the EJid bores down to the depths of the storages and storage chambers For example, they are hollowed out horizontally at the exit of at least one inlet shaft or inlet staircase, in such a way that that the tubes open into the storage chambers, whereupon by means of a known means the clogging of the or between

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the inlet shaft and the storage chambers provided inlets after finishing the excavator, sore lining work if necessary follows, and after drying the linings, the first filling with liquid gas at a very low level Temperature of the storage chambers at the exit of the earth boreholes, at the same time the inlet shaft is flooded and the sealing means provided between the shaft and the chambers are sealed by freezing.

After lining the walls of the storage container, optionally with cement or concrete or a thermal Isolating agent, followed by drying with fine air, then blowing out with dry nitrogen and after that Closing the inlets to the vertical shaft is a blowing out of the shaft with carbonic anhydrite under pressure realized what noticeably and at the same time the filling of the container with liquid gas and the filling of the inlet shaft with water follows.

The invention also relates to a pressure vessel. For the storage of liquid gas at very deep Temperature and is characterized in particular by the fact that it has one or more underground storage chambers, a unit of tubular bores, especially for the storage and extraction of the stored liquefied gas, at least one of contains the chambers insulated inlet shaft, which is closed by known locking means and so filled with water

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fills 1st that the forming ice at the bottom of the shaft the seal secures · The walls of the storage chamber are completely or partially covered over their entire surface with a suitable insulating lining to prevent the binding to limit the soil heat in the stored product to a certain extent · This lining can be used if necessary a layer of cement or concrete is used

The subject matter of the invention is shown schematically in an exemplary embodiment in the accompanying drawings shown:

Fig. 1 shows schematically a vertical section through an underground storage container according to the invention ;

Pig 2 shows schematically a hole for the operation of the storage according to the Fig, 1.§

3-5 show schematically in cross section the configuration of various chambers, one underground Form storage according to the invention

In order to achieve underground storage for liquid gas at low temperature according to the invention, laid first the pipes down to the depths of the underground storage chambers. The bores have an outer, cylindrical one Casing or casing, which consists of watertight masses and is applied to the drilling wall

A vertical shaft is drilled into the depth, a little above the excavated storage chambers

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In this way you get a sump for collecting water that water-bearing layers can penetrate The walls of the shaft are usually covered with a layer of concrete «

From the base of the shaft, storage corridors or storage chambers are dug horizontally according to a known method. These corridors are preferably made in an impermeable soil to prevent water from entering the expansion work and at the start of the reclamation of the container to avoid a layer of calcareous sandstone is deposited at a depth of 15 m

- ■ Figures 3, 4 and 5 show configurations of passages that are excavated at the exit of one or more inlet shafts · Figure 3 shows a configuration of chambers in the form of teeth of a. Comb · Figure 4 shows an embodiment in the shape of a square or of beehives · Figure 5 shows radially arranged corridors ·

It is evident that the choice of excavation, the indentation of the boreholes depends on the operating conditions are intended for the container The cross-section of the aisles and an extension depend on the

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the depth of the floor in order to achieve the maximum groove volume at the minimum Obtain cost price. The layout and the spatial relationship of the various chambers will be such that the soil conditions allow convenient operation of the container, be it that the container is partitioned or its various Chambers are permanently in open communication with one another · In various illustrated embodiments the outer corridors are under more pressure than the others because they are most exposed to the heat input from the ground are · Because of the construction of the container, there is scope for different few meters accordingly the soil conditions with knowledge of the dimensions and the distance between the storage aisles, the laying of an insulating layer on the aisle walls, if the supply of heat plays an essential role in the operation of the container and the laying vertical, metallic plates facilitate the heat exchange and the formation of liquid layers in the container avoid. Depending on the nature of the soil in which the storage chambers are hollowed out, one uses a lining of cement or concrete, or £ on leaves the rock bare, after the hollowed-out walls have dried, whether they are covered or uncovered with concrete or cement, one or more water-blocking dams are built for sealing the place where the corridors open into the vertical inlet shaft A manhole or other suitable access is provided, which enables the sealing of the water shut-off device (s).

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the dams or the like. which has a certain slight moisture and controls this drying by measuring devices of the temperature and the degree the humidity at the entrance and exit of the container. If the operation of the tank requires insulation that from a plastic foam compound, Berlit concrete or the like can, this insulating compound is applied after a first drying and a new ventilation is carried out to achieve a perfect To achieve drying dex · insulating layer.

After the cavity has sufficiently dried out

one forms the suitably arranged manhole or manholes in the water-blocking dams and blows the Containers with dry nitrogen flowing through the operating bores Maintain pressure to prevent the ingress of air or natural gas to avoid in the storage chambers

Now the inlet duct or ducts are blown out with carbonic acid, which form in the duct base brought in by snow. To allow diffusion between the To avoid carbon dioxide and atmospheric air, the inlet shaft is closed with a lid on top. On that the sealing of the operating bores is investigated and, however, with the injection of the liquefied gas at low temperature started with a certain overpressure in the storage chambers.

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In order to seal the or between the

or to reach the water-blocking dams provided for the shafts and the storage chambers, the shaft or shafts, the walls of which have a temperature of around 0 C, are progressively filled mit Wasser «This creates an icy finish that completely seals the passages between the Shaft and chambers guaranteed

The shaft is still filled with water in the same way as the storage chambers are filled with liquid gas is continued. In this way si'ch the pressures on the water-blocking dams equalize, which enables the operation of the container at a pressure which is equal to the hydrostatic pressure in the depth of the container by a Siphon pump corresponds · At the same time, a floor opening through a dead end is avoided, which allows the accumulation of explosive natural gas and brings it under control «

Pumps and preheating means have been provided to melt the ice in the shaft · Wenn After a certain operating time, access to the container becomes necessary, this access is due to the melting of the ice by means of any heat source such as steam, hot water, electricity or the like · easily · The melt water separates into the extent to which it disappears by pumping in the shaft, for example above the ice cap

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For commissioning the storage chambers. you get a © complete sealing of the cavity and the fluss®s a preservation through the & m £ the wall of the cavity ■ applied insulating layer iasad avoids any icing v & si devices vm.d. Torricht ^ rn-gess. In. the camp from SnöSi «=» lung ο

The dargestellt® in Figure 1 container containing one or more underground chambers £ o _s m in a number of Io in soil depth are dug "number II designates the Dacfe. of the hammers i © ₉ the number 12 the @ m soil and the number 13 the level of the water between its liquid and its gaseous state _o The 1 © is at the exit of a vertical seliacate £ 4 of Figure 15 at a depth of some 1 © m Excavated »By access between the vertical snout 14 and the ICammer 1®, a water-blocking passage l6 made of bed or another doorway is preferably designed as a manhole« While the & Batriebe-s cools &&& ± n the chamber 'iq existing liquid gas Hait deep Teiapex ^ atmr in the vicinity of the chamber wall ice. and dam ®S? w && the shaft 1% _S which had been filled with water "pumice üismasse 17 i 'a · shaft base ensures vol2k © Esnsane AbdisIuttHig in the joint between the chamber Io and the shaft i4 _e Per upper shaft part above the layer of ice 17 mrd is filled with water up to the corridor and avoids any accumulation of iron,

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44

plosive gas from stored fiturgas such as methane. That
Water comes from the groundwater that is on the drawing
Code numbers 2o and 21 carry «It is easily possible
to complete the filling of the shaft from other sources. The reference number 22 shows schematically. a
Location for the melting of the ice and the pumps for the thawed water, if you want to penetrate the container after completely emptying and blowing out all traces of gas.Due to a lack of such means you need many days to thaw the ice seal in the bottom of the shaft,
resulting in a long shutdown of the system
Has·

FIG. 1 and FIG. 2 show in detail

Bores 30 for the connection of Figure 15 with the chambers Io of the underground storage container

The bores 3o essentially form three pipes. An outer pipe represents the outer shaft lining 31, which is cemented out between the corridor 15 and the chamber Io. An outer tube 52 extends to the roof 11 of the chamber Io and is in the outer tube forming the shell
31 arranged coaxially. An inner tube 33 arranged coaxially in the tubes 31, 32 extends from the corridor 15 to
to the bottom 12 of the chamber Io. As can be seen from Figure 2,
are the tubes 31, 32, 33 in Figure 15 on one
Head shaft-forming bracket suspended in such a way that the

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different coaxial tubes have a suitable distance from one another by means of heat-insulating layers. This means that no technical problems arise due to distortion of the tubes during operation. The inner tube 33 is used to inject and withdraw the liquid in the container lo the intermediate tube 32 is useful during the injection or withdrawal of the gas which is -within the container above the liquid level created during pressure equalization. The said gap is also useful for the return of the liquid in the container. The space between the intermediate pipe 3 ² and the casing tube 31 serves to limit the heat exchange with the bottom heat and prevents the cement jacket 31 is exposed to excessive temperature changes _o To improve protection for the sheath 31 is located on the outer periphery of the intermediate tube 32 a Cover J> h. from an insulating compound such as polyurethane or the like. The inner tube 33 and the intermediate tube 32 are preferably made of a material with a resistance to low temperatures, while ordinary steel can be used for the outer jacket tube 31 ^,! the choice of which is made possible by the protective layer · The inner tube 33 ends in the bottom 13 of the container Io in a fall shaft 35 with two levels

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agreement of the fall shaft 35 takes place, for example, by a device lowered on a cable and passing through a prepared lock chamber

Figure 2 shows schematically the connections

between the support of the pipe 33 and have discharge lines 4i and 42 via two valves 43, 44 through the valve 36. The line 4l is used for the storage of natural liquid gas a methane ship and the line 42 to consumer points, to the location of regasification or to a pumping station

In the space between the inner tube 33 and the intermediate tube 32, two valves 51 »52 are connected. The valve 51 is connected to the line 53 to the transport network and / or without the interposition of a display device with the introduction of the gas under pressure in the container · The line 54 in the valve 52 leads to a reverse gasification station. A valve 60 is used for the inlet in the intermediate space between the outer jacket 31 and the intermediate pipe 32, for example for blowing out or some other purpose, while normal operation or for the commissioning of the system

For the balance between the heat absorbed by the natural liquid gas, which changes from its boiling temperature under atmospheric pressure to a pressure corresponding to the pressure in the container. on the one hand and that from the soil into the liquid of the

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eisistromeH.de WMrsie aacleareraeitßg is the besoreiner R © g © lnng sweeiaslßlge Ams dee Srsinde is located, see the jLagerkaraaerEi a® getsxsse Amzalal of equipment ^ rIe 'Tem- = azs. versehiedeiaeit St @ 12®m of the walls and ira be ^ Qesteina Bs wexfdsir. aticlE Eielustäae am d * s, wandering
-am rob the control ,, w @ 3sn the container
Pressure in the company is »

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Claims (1)

File: 63/2/26 Soh / W claims 1. method of erecting an underground storage tank of liquid gas at very low temperature, characterized in that after the introduction of pipes (31 | 32, 33) for operation, the Erdbohrngen (3o) to into the depth of the storages and storage buckets (Io), for example horizontally at the outlet of at least one inlet shaft (14) or inlet whole hollowed out v / ground, in such a way that the pipes open into the storage chambers, whereupon by means of a known By means of, for example, a concrete dam (16), the clogging of the one or more between the inlet shaft and the storage chimneys planned inflows after the completion of the dredging work and, if necessary, carcassing work. follows, and after the drying de. Linings the first precipitation with liquefied gas at a very low temperature of the storage chambers at the exit of the Earth drilling takes place, at the same time the inlet shaft is sunk under water, and by freezing between the shaft and the closure means provided for the chambers are sealed » 2, method of first dropping a container according to claim 1, characterized in that after the walls of the storage container (lo) have been lined with cement or concrete or an insulating thermal insulating agent, drying is carried out with dry air, then lined with dry nitrogen, closing the accesses to the shafts (14), then cleaning the shafts with carbon anhydride. On that begins filling the container with irlissiggas and the 809803/0295 File: 63/2/26 ScIiAT Precipitation of the access shafts with water in such a way that the equilibrium the hydrostatic pressures in said shafts and in the container is maintained, whereupon a perfect Sealing in the manholes follows. 3 · Containers for- underground storage of Liquid at very low temperatures under pressure, according to. Claim 1, characterized in that means (22) for melting of the ice and the Puiapwassers in usn feed shafts (14-) are provided. The patent attorney Di 0 BATH ORIGINAL 8098-03 / 0295