EP2622300A2

EP2622300A2 - Device for storing hot, corrosive fluids and use of the device

Info

Publication number: EP2622300A2
Application number: EP11755318.0A
Authority: EP
Inventors: Jürgen WORTMANN; Fabian Seeler; Felix Major; Kerstin Schierle-Arndt; Otto Machhammer; Günther Huber; Stephan Maurer; Karolin Geyer; Michael Lutz; Martin GÄRTNER
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2010-09-29
Filing date: 2011-09-08
Publication date: 2013-08-07
Also published as: WO2012041679A2; ZA201303026B; BR112013005908A2; CA2808172A1; JP2013545063A; KR20130124496A; CN103140733A; AU2011310848A1; MA34549B1; MX2013002594A; CL2013000858A1; WO2012041679A3

Abstract

The invention relates to a device for receiving hot, corrosive liquids (7), comprising a chamber enclosed by a wall (21) for receiving the liquid (7), wherein the chamber comprises an interior insulation (19). The invention further relates to a use of the device for storing corrosive liquids for storing a heat storage medium comprising sulfur.

Description

Device for storing hot, corrosive liquids and use of the device

description

The invention relates to a device for receiving hot, corrosive liquids, comprising a space enclosed with a wall for receiving the liquid. Furthermore, the invention also relates to a use of the device.

A device for receiving hot, corrosive liquids, for example, a container which is used for receiving a heat storage medium in a solar power plant. In a solar power plant, heat is generated during the daytime, as long as the sun is shining, with the help of solar energy. The heat is used to generate electricity. In general, the heat is used to evaporate water and to drive a generator to generate electricity with the generated water vapor. In order to operate a solar power plant continuously, solar energy is used to heat up a heat storage medium. This is stored in a well insulated container. To remove heat, for example when the sun is not shining, the heated heat storage medium is removed and used, for example, to evaporate water. Here, the heat storage medium gives off heat and is cooled. The cold heat storage medium is then passed, for example, into a second cold storage storage tank. To enable uninterrupted operation in a solar power plant, large solar power plants require very large heat storage. In order to evaporate the water in a solar power plant and to heat the steam to a temperature that is reasonable for operation, it is necessary to heat the heat storage medium to correspondingly high temperatures. For example, a heat accumulator is currently being operated in a solar power plant with a working temperature in the range between 290 and 390 ° C. In addition, an attempt is currently being made to extend the temperature range to 550 ° C or even to temperatures above it.

As heat storage media, for example, salt melts are used. Due to the large amount of heat storage medium needed to operate a large solar power plant, alternatives are also sought here. Alternative heat Storage media are, for example, also those containing sulfur. Both molten salts and sulfur-containing thermal storage media cause corrosion at high temperatures to the usually made of steel containers. For example, some nitrate melts at temperatures of more than 550 ° C can lead to embrittlement of various stainless steels. Although the stainless steels remain stable, they are sensitive to shocks. At high sulfur-containing storage materials, for example sulfur, containing 1 wt .-% potassium sulfide, at temperatures above 350 ° C, a noticeable corrosion is generated, which increases with increasing temperature from 400 ° C to a rapid thorough destruction of typical iron and nickel based stainless steels leads. Even chloride-containing molten salts are highly corrosive at high temperatures. At lower temperatures, the corrosivity is much lower, and sometimes not at all.

Materials that resist the corrosive substances even at high temperatures are, for example, ceramics and glasses. In general, however, these can not be connected to large structures, as is necessary for the containers for heat storage, seal-free. Applied sealing material can be corrosively attacked at high temperatures. In addition, these materials are generally brittle and, when connected to a building, can not carry high internal pressures.

Object of the present invention is therefore to provide a device for receiving hot, corrosive liquids, which is corrosion resistant and dense and has sufficient mechanical stability to accommodate large amounts of liquid can.

The object is achieved by a device for receiving hot, corrosive liquids, which comprises a wall enclosed space for receiving the liquid, wherein the space has an internal insulation.

The internal insulation can either rest directly against the wall of the container or it can be formed a gap between the inner insulation and the wall.

The internal insulation prevents the hot liquid contained in the space from coming into contact with the wall. Due to the insulating effect of the internal insulation, the temperature of the side facing the wall is significantly lower than the temperature of the hot liquid. This will achieve that the temperature of the wall bounding the space can be kept below the temperature at which corrosion occurs.

In order to protect the internal insulation, especially in the case of a gap between the internal insulation and the wall of the space in which the liquid is contained, from inadmissible forces acting thereon, the internal insulation preferably has passages through which the liquid can flow. This adjusts a pressure balance on the inside of the insulation and the outside of the insulation. The internal insulation thus does not need to be stable against an internal pressure. In particular, when the gap between the inner insulation and the wall is not uniform, or even the inner insulation partially rests against the wall and partially creates a gap, liquid flows through the passages in the gap until a pressure equalization occurs. A deformation of the inner insulation, which could possibly lead to destruction, is thereby avoided.

The design of the passages is such that liquid can flow into the passages, but does not use convection. This allows liquid to flow out of the container through the passages, but no mass transfer occurs in the passages once they are filled. In particular, in the case of a low thermal conductivity of the liquid to be stored, for example in the case of a molten sulfur melt, the liquid contained in the passages then also acts in an insulating manner. Although the liquid comes into contact with the wall of the room due to the passage through the passages, it has a lower temperature than the liquid in the reservoir, the thickness of the insulation being chosen such that the temperature in the region of the wall is so low that that no or at least minimal corrosion occurs. In order to compensate for a different thermal expansion of the material of the inner insulation and the wall, is enclosed with the space, it is preferred if the inner insulation has expansion joints. The expansion joints are preferably also sized so that no convection begins therein. In a preferred embodiment, the passages in the inner insulation for pressure equalization simultaneously serve as expansion joints, which are used to prevent destruction of the inner insulation by thermal expansion. In this way it is possible to control even loads due to temperature changes without destroying the internal insulation. The extent of the passages and / or the expansion joints is dependent on the viscosity of the liquid contained in the space.

Even with open-pore refractory insulating blocks, from which the internal insulation can be made, for example, although reducing the insulation quality of Dämmsteine in the pore-penetrating liquid, but the low thermal conductivity of the liquid, for example, from sulfur enough to sufficiently strong Build up insulation. The internal insulation can be constructed, for example, from essentially cuboidal elements. Substantially parallelepiped elements also include elements in which the width increases outwardly to conform to a container having a circular cross-section so that the expansion joints between the elements have a uniform width, as well as elements in the form of circular segments attached to are adapted to the diameter of the container are designed. The passages or expansion joints are, for example, gaps between the cuboidal elements. A further prevention of convection is possible in that the cuboidal elements are stacked offset to build the internal insulation. A gap between two cuboidal elements is then only as high as such a cuboidal element and is interrupted by a parallelepiped element of the next row.

The internal insulation can be both self-supporting as well as formed by attachment of insulating elements on the wall. In the case of a self-supporting insulation, for example, insulating elements are stacked to form an inner wall, whereby it can stand freely or rest against the wall of the room. It is particularly preferred if the self-supporting internal insulation has expansion joints. In order to further improve the insulation, it is possible to form a second insulating layer between the wall and the inner insulation. The second insulating layer may be formed of the same material as the internal insulation. It is also possible to use two different materials. If a second insulating layer is accommodated between the wall and the inner insulation, it is possible, for example, for the inner insulation, which is preferably self-supporting, to be formed from an abrasion-resistant material, for example aluminum oxide refractory brick, and the second insulating layer to be highly insulating Material, such as glass foam, contains. The internal insulation can also be made up of more than two layers. In this case, at least one layer is preferably a self-supporting internal insulation, the remaining layers may or may not be self-supporting. It is also possible, for example, to build up alternately self-supporting insulating layers and highly insulating material in several layers. Furthermore, however, it is also possible that all layers of the insulation are self-supporting.

In particular, when the second insulating layer is not self-supporting, it is advantageous if this is limited both on the inside and on the outside by a self-supporting internal insulation. However, it is preferred if each layer of the insulation is self-supporting.

In a preferred embodiment, a seal made of a corrosion-resistant material is received between the inner insulation and the wall. The seal made of corrosion-resistant material may be, for example, an inliner, for example in the form of a corrugated sheet. By using a seal made of a corrosion-resistant material, it is possible to use a non-corrosion-resistant metal for the wall. Corrosion-resistant materials, for example corrosion-resistant stainless steels, are generally expensive and also have lower strength values than steels which are not resistant to corrosion in relation to the liquid contained in the space. By using the seal made of the corrosion-resistant material, it is possible to make the wall of the enclosed space, for example a container, of a steel which is not stable to the liquid contained in the space. The seal made of the corrosion-resistant material prevents the liquid contained in the space from coming into contact with the wall.

The device for storing the hot, corrosive liquid is, for example, a container. This generally has a wall and a lid, so that a closed space is formed, in which the hot, corrosive liquid is contained. The wall of the container may, for example, from the typical materials for container construction z. B steel or stainless steel to be built. In particular, if a seal made of a corrosion-resistant material is used, it is possible to use materials for the wall of the container, which are not resistant to corrosion compared to the liquid contained in the container.

Suitable corrosion-resistant materials from which the seal can be made are, for example, graphite or aluminum. If the device for storing hot, corrosive liquids is a container, it is usually closed with a container lid. On the container lid insulating elements are then also attached. Due to the insulation of the container lid, it is also avoided in the area of the container lid that - especially when the container is completely filled - the container lid comes into contact with the hot, corrosive liquid. In addition, it is avoided that heat is released through the container lid to the environment.

In addition to a container, the storage space enclosed by a wall can also be a cavity in the ground. On the one hand, it is possible for the cavity to be a natural cavity; alternatively, it is also possible to artificially create a cavity, for example. The advantage of a cavity in the ground is that greater heights of the memory can be realized, since they can be loaded by a higher hydrostatic pressure than conventional containers, since the forces occurring due to the hydrostatic pressure are absorbed on the wall of the soil. A large height for the room is particularly useful if the contained in the room, corrosive liquid is a heat storage, which is to be operated as a stratified storage. In a heat storage system operated as a stratified storage tank, there is cold liquid at the bottom and hot liquid at the top. Due to a high altitude, the time until a temperature compensation due to heat conduction is increased. In this way, it is possible to realize very large heat storage, for example, for solar power plants, which can be used for example as day storage, weekly storage and in principle also monthly storage or even annual storage. This is particularly helpful because natural energy sources such as Wnd and Sun fluctuate.

Another advantage of a cavity in the ground is that a heat storage for a solar power plant can be operated well above 440 ° C even under pressure and at maximum temperature, as even with large storage systems, a system pressure of more than 1 bar can be applied. Another advantage is that the hot, corrosive liquid can be stored in a cavity in the ground in the absence of air, which can greatly reduce the risk of fire. The in-situ insulation of the cavity in the soil prevents the hot, corrosive liquid from coming into contact with the soil and releasing substances from the soil or reacting with them and carrying away the solutes or the reaction products. The substances or reaction products dissolved from the soil can, for example, be added to other components of a plant in which the Device for storing hot, corrosive liquids is used, causing damage caused by increased corrosion or deposits.

A cavity in the ground, for example, can be artificially generated completely above ground, for example, by artificially heaping up a mound in which such a cavity is formed. Furthermore, a cavity in the ground can be partially underground, whereby both naturally occurring cavities and artificial cavities can be used. It is also possible that the cavity is completely subterranean. In this case, natural cavities are used in particular. According to the invention, an internal insulation is introduced into the cavity in the ground. This serves in particular to avoid, as already described above, that liquid which is stored in the cavity dissolves substances from the soil or reacts with substances from the soil. As the material of the internal insulation, both when used in a container as well as when used in a cavity in the ground, are suitable, for example, alumina, silicon carbide, silica, aluminum foam, glass foam or mixtures thereof. It is also possible to provide several layers, wherein the layers can be made of different materials.

In particular, when the device for storing the hot, corrosive liquid is a container, in particular a container with a metal wall, for example a steel wall, it is possible that the container wall, despite the internal insulation has a temperature that lead to injury, for example, when touched can. In this case, it is preferable if the container wall is additionally surrounded by an outer insulation. For external insulation, for example, mineral fiber mats or standard glass foam panels are suitable. With an additional covering by a sheet metal, such as zinc sheet, it can be avoided that moisture penetrates into the insulation.

The inventive device for receiving hot, corrosive liquids is particularly suitable for receiving a heat storage medium in a solar power plant, such as a parabolic trough solar power plant. Heat storage media that may be employed include, for example, molten salts or sulfur-containing thermal storage media. Sulfur-containing heat storage medium is in particular elemental sulfur. In order to adapt the vapor pressure and the melt pressure, it is advantageous to add at least one anion-containing additive to the sulfur. Particularly suitable as anion-containing additives are those which do not oxidize the sulfur at the operating temperature to corresponding oxidation products, for example sulfur oxides, sulfur halides or sulfur oxide halides. It is furthermore advantageous if the anions-containing additives dissolve well in the sulfur.

Preferred anion-containing additives are ionic compounds of a metal of the Periodic Table of the Elements with monatomic or polyatomic singly or multiply negatively charged anions.

Metals of the ionic compounds are, for example, alkali metals, preferably sodium, potassium; Alkaline earth metals, preferably magnesium, calcium, barium; Metals of the 13th group of the Periodic Table of the Elements, preferably aluminum; Transition metals, preferably manganese, iron, cobalt, nickel, copper, zinc.

Examples of such anions are: halides and polyhalides, for example fluoride, chloride, bromide, iodide, triiodide; Chalcogenides and polychalcogenides, for example, oxide, hydroxide, sulfide, hydrosulfide, disulfide, trisulfide, tetrasulfide, pentasulfide, hexasulfide, selenide, telluride; Pnicogenides, for example amide, imide, nitride, phosphide, arsenide; Pseudohalides, for example, cyanide, cyanate, thiocyanate; complex anions, for example, phosphate, hydrogen phosphate, dihydrogen phosphate, sulfate, hydrogen sulfate, sulfite, hydrogen sulfite, thiosulfate, hexacyanoferrate, tetrachloroaluminate, tetrachloroferrate. Examples of anion-containing additives are: aluminum (III) chloride, iron (III) chloride, ferrous sulfide, sodium bromide, potassium bromide, sodium iodide, potassium iodide, potassium thiocyanate, sodium thiocyanate, disodium sulfide (Na ₂ S), disodium tetrasulfide (Na ₂ S ₄ ), disodium pentasulfide (Na ₂ S ₅ ), dipotassium pentasulfide (K ₂ S ₅ ), dipotassium hexasulfide (K ₂ S ₆ ), calcium tetrasulfide (CaS ₄ ), barium trisulfide (BaS ₃ ), dipotassiumselenide (K ₂ Se), tripotassium phosphide ( K ₃ P), potassium hexacyanoferrate (II), potassium hexacyanoferrate (III), copper (I) thiocyanate, potassium triiodide, cesium triiodide, sodium hydroxide, potassium hydroxide, cesium hydroxide, sodium oxide, potassium oxide, cesium oxide, potassium cyanide, potassium cyanate, sodium tetraaluminate, manganese (II) sulfide, cobalt (II) sulfide, nickel (II) sulfide, copper (II) sulfide, zinc sulfide, trisodium phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, disodium sulfate, sodium hydrogen sulfate, disodium sulfite, sodium hydrogen sulfite, sodium thiosulfate, tripotassium sphat, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, dipotassium sulfate, potassium hydrogen sulfate, dipotassium sulfite, potassium hydrogen sulfite, potassium thiosulfate. Anions containing additives for the purposes of this application are furthermore mixtures of two or more compounds of a metal of the Periodic Table of the Elements with monatomic or polyatomic formally singly or multiply negatively charged anions, preferably anions composed of non-metal atoms. In this case, according to the current state of knowledge, the quantitative ratio of the individual components is not critical.

The mixture according to the invention preferably contains elemental sulfur in the range from 50 to 99.999% by weight, preferably in the range from 80 to 99.99% by weight, more preferably 90 to 99.9% by weight, in each case based on the total mass of mixture according to the invention.

The mixture according to the invention preferably contains anions-containing additives in the range from 0.001 to 50% by weight, preferably in the range from 0.01 to 20% by weight, more preferably 0 to 1 to 10% by weight, based in each case on the total mass the mixture according to the invention.

The mixture according to the invention may contain further additives, for example additives which lower the melting point of the mixture. The proportion of further additives is generally in the range from 0.01 to 50% by weight, in each case based on the total mass of the mixture.

Furthermore, it is also possible to use mixtures of alkali metal polysulfides of the general formula (M ¹ _× M ² _(1- _x) ) ₂ S _y , where M ¹ , M ² = Li, Na, K, Rb, Cs and M ¹ not equal to M ² and 0.05 <x <0.95 and 2.0 <y <6.0. In a preferred embodiment of the invention, M ¹ = K and M ² = Na.

In another preferred embodiment of the invention, 0.20 <x <0.95. In a particularly preferred embodiment of the invention, 0.50 <x <0.90. In another preferred embodiment of the invention, 3.0 <y <6.0. In a particularly preferred embodiment of the invention y = 4.0, 5.0 or 6.0.

In a particularly preferred embodiment of the invention, M ¹ = K, M ² = Na, 0.20 <x <0.95 and 3.0 <y <6.0. In a most preferred embodiment of the invention, M ¹ = K, M ² = Na, 0.50 <x <0.90 and y = 4.0, 5.0 or 6.0. Also suitable are mixtures of alkali metal polysulfides and alkali metal thiocyanates according to the general formula

((M ¹ _× M ² _(1- _x) ) ₂ S _y ) _m (M ³ _z M _(1- _z) SCN) ₍₁ _ _m) where M ¹ , M ² , M ³ , M ⁴ = Li, Na, K, Rb, Cs and M ^{1 is} not equal to M ² , M ^{3 is} not equal to M ⁴ and 0.05 <x <1, 0.05 <z <1, 2.0 <y <6.0 and m the Mole fraction with 0.05 <m <0.95.

In a preferred embodiment of the invention, M ¹ and M ³ = K and M ² and M ⁴ = Na.

In a further preferred embodiment of the invention, 0.20 <x <1. In a particularly preferred embodiment of the invention, 0.50 <x <1. In another preferred embodiment of the invention, 3.0 <y <6.0. In a particularly preferred embodiment of the invention y = 4.0, 5.0 or 6.0.

In a further preferred embodiment of the invention, 0.20 <z <1. In a particularly preferred embodiment of the invention, 0.50 <z <1.

In a further preferred embodiment of the invention, 0.20 <m <0.80. In a particularly preferred embodiment of the invention, 0.33 <m <0.80.

In a particularly preferred embodiment of the invention, M ¹ and M ³ = K, M ² and M ⁴ = Na, 0.20 <x <1, 0.20 <z <0.95, 3.0 <y <6, 0 and 0.20 <m <0.95.

In a very particularly preferred embodiment of the invention, M ¹ and M ³ = K, M ² and M ⁴ = Na, 0.50 <x <1, 0.50 <z <0.95, y = 4.0, 5 , 0 or 6.0 and 0.33 <m <0.80. In a further particularly preferred embodiment of the invention, M ¹ and M ³ = K, x = 1, z = 1, y = 4.0, 5.0 or 6.0 and 0.33 <m <0.80.

In a further particularly preferred embodiment of the invention, M ¹ and M ³ = K, x = 1, z = 1, y = 4 and m = 0.5. In a further particularly preferred embodiment of the invention, M ¹ and M ³ = K, x = 1, z = 1, y = 5 and m = 0.5. In a further particularly preferred embodiment of the invention, M ¹ and M ³ = K, x = 1, z = 1, y = 6 and m = 0.5.

In addition to the use of a heat storage medium in a solar power plant, however, the device according to the invention can also be used as a container or reactor, which are exposed to high-temperature corrosion and are always operated with the same medium. For operation with different media, the device according to the invention is unsuitable because the space enclosed by the wall can only be cleaned with difficulty. Unavoidable gussets and crevices hold back media residues that are difficult or impossible to remove.

Embodiments of the invention are illustrated in the figures and are explained in more detail in the following description.

Show it:

FIG. 1 shows a device designed as a layer accumulator for receiving hot, corrosive liquids;

a section of a self-supporting internal insulation, an exemplary construction of an internal insulation with insulation boards, a structure of a container lid with insulating elements, a structure of a container wall with self-supporting internal insulation, a schematic representation of a device for receiving hot, corrosive liquids as a cavity in the ground,

FIG. 7 shows the structure of the self-supporting internal insulation in a cavity in the ground, FIG. 8 device designed as a storage composite for receiving hot, corrosive liquids, FIG. 9 shows a flange connection with internal insulation,

Figure 10 is a flap with internal insulation.

FIG. 1 shows a device designed as a layer store for receiving a hot, corrosive liquid.

A stratified storage 1, as shown in FIG. 1, can be used, for example, as a heat store in a solar power plant. The stratified storage 1 comprises a container 3, which is constructed, for example, from a metallic material, for example steel. For this purpose, a container wall 5 is made of the metallic material, wherein the wall thickness of the container wall 5 is selected so that it is mechanically stable against the pressures occurring in the container. In this case, in particular the downward increasing hydrostatic pressure of a liquid contained in the container 7 should be considered. In addition, a further lid 1 1 may be provided, which rests on completely filled container 3 on the liquid contained in the container 3 7, so that no gas is contained in the container 3. In order to compensate for fluctuations in the liquid level, it is possible for 1 1 compensation areas 13 to be provided on the further dekel. These can be designed, for example, in the form of a bellows. By means of the compensation region 13, the further cover 1 1 can be positively connected to the container wall 5, for example by a welding process. As a result, a gas-tight connection is possible. With an increase in the liquid level or a decrease in the liquid level then raises or lowers the other lid 11 so that it always closes the container so that no gas is contained in the container. Alternatively or additionally, it is also possible to realize the compensation of changes in the volume of the storage material when the temperature changes by supplying or removing liquid, for example from a buffer tank.

When using the container 3 as a stratified storage 1 is located in the upper region of the container 3, a first manifold 15. About the first manifold 15 evenly hot liquid can be added to the container. At the same time, in order to keep the liquid level in the container constant, via a second manifold 17 on Bottom of the container removed 3 colder liquid. Cold liquid is uniformly withdrawn through the first distributor 15 and the second distributor 17, so that preferably no convection flow and therefore very little vertical heat conduction in the container are established. In this way it is possible to store liquid in the container in such a way that the lower part contains the generally colder liquid with a higher density and in the upper part the warmer liquid with a lower density. In the ideal case, the liquid in the container has two temperatures, namely a higher temperature in the upper region and a lower temperature in the lower region. Between the hot and the cold area, a temperature boundary layer is formed. Since the heat conduction in the liquid can not be prevented, in the real case, however, no sharp separation between hot and cold liquid is possible, but it forms a temperature transition from the hot to the colder liquid. Due to thermal conduction, the transition becomes increasingly blurred as the duration of storage increases.

In a solar power plant, the supply of hotter liquid via the first manifold 15 and the removal of colder liquid via the second manifold 17, when the liquid used as a heat storage medium is heated by solar energy. If the sun is not shining, but electricity is still to be generated in the solar power plant, the heat stored in the heat storage medium is used to evaporate water to drive the turbines driving the generators. For this purpose, the hot heat storage medium is removed from the container 3 via the first distributor 15, releases heat into a heat exchanger in which the water used as operating liquid is vaporized and superheated, and the cooled heat storage medium is then at the bottom via the second distributor 17 Area of the container fed again. By removing hot heat storage medium from the container 3 or by the removal of cold heat storage medium during heating, respectively shifts the temperature boundary layer in the container 3. When heating the heat storage medium, i. When the hot storage medium is supplied via the first distributor 15 and the colder liquid is removed via the second distributor 7, the temperature boundary layer shifts downward, whereas when the heat stored in the liquid 7 is used, the temperature boundary layer is displaced upward decreases in hot heat storage medium in the container 3 and the amount of cold heat storage medium whose heat has already been used, increases.

As the liquid 7 serving as a heat storage medium, for example, a molten salt or a sulfur-containing heat storage medium is used. As sulfur-containing heat storage medium is particularly elementary Sulfur, which may, however, be contaminated or may contain other additives. Both molten salts and sulfur are highly corrosive at higher temperatures than ferrous or nickel containing materials. For example, nitrate melts at temperatures of more than 550 ° C lead to the embrittlement of stainless steels. The stainless steels remain stable, but are shock sensitive. Sulfur-containing heat storage media, for example, sulfur with 1% potassium sulfide, produce in typical iron / nickel stainless steels at temperatures above 350 ° C, a noticeable corrosion, which leads to increasing temperature of 500 ° C in a short time for sweeping destruction of stainless steels.

Even chloride-containing molten salts are highly corrosive at high temperatures.

To prevent corrosion, according to the invention an internal insulation 19 is received in the container 3. The internal insulation 19 prevents the liquid 7 contained in the container 3 from coming into contact with the wall 21, which encloses the space receiving the liquid 7. In addition, due to the insulation, the temperature at the wall 21 is significantly lower than the temperature of the liquid 7 in the container 3. An exemplary construction of the internal insulation 19 is shown in FIG. The internal insulation, as shown in Figure 2, is self-supporting. For this purpose, essentially cuboidal, optionally to match the rounding of the container also slightly trapezoidal elements 23 or elements 23 in the form of circular segments are arranged offset in two rows. The column 25 serve to compensate for different temperature expansions of the materials of internal insulation 19 and container wall 5. To build the internal insulation, as shown in Figure 2, the cuboidal elements 23 stacked one above the other in rows, wherein it is preferable to each stacked cuboidal elements 23 also arranged offset from one another. The staggered arrangement, the column 25 are limited in their geometric extension. Furthermore, it is preferred that the gaps 25 are dimensioned so that no convective flow is formed. Although liquid 7 can flow into the column 25, however, a constant mass transfer in the gaps after they have been once filled with the liquid 7 should be avoided. In particular, in the case of liquids having poor thermal conductivity, as is the case, for example, with a molten sulfur, the liquid contained in the gaps 25 then also insulates. The design in two staggered rows, as shown in Figure 2, it is avoided that liquid passes through the inner insulation 19 to the wall 21. In an alternative embodiment, it is also possible for the internal insulation to be constructed from a row of cuboidal elements 23. In this case, the liquid passes through the gap 25 to the wall 21. Due to the insulating effect of the insulation 19 and the design of the column 25 such that no convective flow occurs, the temperature of the column 25 is also reduced flowed liquid, so that the temperature of the liquid 21 coming into contact with the wall is lower than the temperature of the liquid 7 in the container 3. The thickness of the insulation 19 is chosen so that the temperature of the liquid passing through the gap 25 is so in that the temperature is below the temperature at which the liquid is highly corrosive to the material of the wall 21.

FIG. 3 shows an exemplary construction of an internal insulation made of insulating boards. In contrast to the embodiment of an internal insulation 19 shown in FIG. 2, the internal insulation 19, which is shown in FIG. 3, is not self-supporting. The internal insulation 19 comprises individual insulation panels 27, which are mounted on the wall 21. The wall thickness of the wall 21 which forms the container wall 5 is selected so that the wall 21 is stable against forces acting on it, for example due to the hydrodynamic pressure of the liquid contained in the container.

For insulation, the insulation boards 27 are fastened to the wall 21, for example, with suitable wall hooks 29. The advantage of using wall hooks 29 is that the individual insulation panels 27 of the internal insulation 19 can be mounted in a simple manner and, if necessary, also dismantled again. In addition to attachment with wall hooks 29, however, it is also possible to attach the insulation panels 27 to the wall 21 in any other manner known to those skilled in the art. For example, it is also possible to bond the insulation boards to the wall 21, for example. However, this has the disadvantage that a simple disassembly is no longer possible.

To compensate for occurring stresses and the insulation boards 27 are mounted so that each between two insulation boards 27, a gap 25 is formed. The dimensions of the column 25 are to be selected in the embodiment shown in Figure 3 so that no convective flow in the gap 25 is formed. As a result, the gap 25 is filled by incoming liquid during filling, but this then remains in the gap 25 and thus also serves for insulation. Since the insulating panels 26 are generally not flush against the wall 21, liquid also flows behind the insulating wall. plates 27. Due to the insulation with the insulation boards 27, the liquid that comes into contact with the wall 21, but already cooled so far that it no longer acts on the wall 21 corrosive. In order to protect the insulation boards 27 against corrosion, it is possible to provide these additionally with a corrosion-resistant coating 31. In this case, any coating known to the person skilled in the art is suitable as the corrosion-resistant coating. Suitable coatings are, for example, coatings with enamel or Al ₂ O ₃ coating.

A coating 31 of the insulation boards 27 is particularly useful if a material is used as the material for the insulation boards 27, which is not stable to the liquid 7 contained in the container. A possible construction of a container lid with insulating elements is shown in FIG.

The construction shown in Figure 4 for a container lid substantially corresponds to the structure of a container wall shown in Figure 3 with insulating panels mounted thereon.

In order to ensure insulation upwards, 33 insulating elements 35 are mounted on the container lid. The attachment of the insulating elements 35 can be done, for example, analogously as shown in Figure 3 by means of hooks 37. However, an attachment for example by screwing or gluing is possible. Depending on the material used for the insulating elements 35 and the liquid to be stored in the container 7, it is possible to coat the insulating elements 35 with a corrosion-resistant coating 31. It is also preferred on the container lid 33 if gaps 25 are formed between the individual insulating elements 35 in order to be able to compensate for different thermal expansions of insulating material of the insulating elements 35 and of the material of the container lid 33.

FIG. 5 shows a construction of a container wall with self-supporting internal insulation.

The container wall 5 is formed by a force-bearing steel shell. This is designed so that it is mechanically stable and can absorb, for example by acting pressures acting forces without deforming. On the inside, the container wall 5 is followed by a corrosion-resistant seal 39. The corrosion resistant Seal 39 is, for example, a stainless steel inliner. This can be designed, for example, in the form of a corrugated sheet. By using the corrosion-resistant seal 39, it is possible to use as the material for the container wall 5 a steel which is not resistant to corrosion with respect to the liquid contained in the container. The corrosion-resistant seal 39 prevents the liquid from coming into contact with the material of the container wall 5.

The corrosion-resistant seal 39 is followed on the inside by a first insulating layer 41. The first insulating layer 41 is preferably self-supporting and composed of quasi-shaped elements which are stacked on top of one another. Between the individual cuboid elements of the first insulating layer 41, it is advantageous if gaps are formed, as is also illustrated, for example, in FIG. The first insulating layer 41 is made of, for example, a high heat insulating material. As a result, a good insulation is achieved. The first insulating layer 41 is followed by a second insulating layer 43. The second insulating layer 43 is made, for example, of an abrasion-resistant material, so that this particular also serves to ensure that the internal insulation 19 is not damaged by movement of the liquid in the container. Also, the second insulating layer 43 is preferably self-supporting and layered, for example, cuboidal elements. Again, it is advantageous if 43 gaps are formed between the individual elements of the second insulating layer in order to compensate for different thermal expansions of the materials of the first insulating layer 41, the second insulating layer 43 and the container wall 5 can. Through the gap 25 between the individual elements of the first insulating layer 41 and the second insulating layer 43, liquid can flow in the direction of the wall 21. The liquid then collects on the corrosion-resistant seal 39. The fact that there is liquid on both sides of the insulation 19, which in each case has the same pressure due to pressure equalization, it is avoided that acts on the insulation 19, a high internal pressure, not from the Outside is compensated. A deformation of the inner insulation 19 is thereby largely avoided.

Since, in spite of the internal insulation 19, the temperature at the container wall 5 can be so high that threatens injuries, for example, in contact with the container wall 5, it is also possible that an external insulation 45 is connected to the container wall 5 on the outside. The outer insulation 45 may be formed of, for example, conventional insulating materials such as mineral fibers or glass fibers. To make the container weatherproof, the outer insulation 45 then becomes For example, covered with sheets 47. The sheets 47 that are used, for example, commercially available zinc sheets, which are particularly weather resistant.

FIG. 6 schematically shows a device for receiving hot, corrosive liquids in the form of a cavity in the ground.

In contrast to the construction shown in FIGS. 1 to 5, it is alternatively also possible to design the device for receiving the hot, corrosive liquid as a cavity 49 in the soil 51. This has the advantage that no container limitation in the form of a container wall 5, which is stable to high pressures, is necessary. The forces acting on the wall 21 forces are absorbed by the soil 51. For example, the device may also be a layered memory. If the device for receiving the liquid is a stratified storage, then a first feed 53 is provided in the upper region, through which hot heat storage medium can be fed into the cavity 49 or can be removed from the cavity 49 and a second feed 55, the opens into the lower region of the cavity 49 and can be removed or supplied via the cold heat storage medium. The function otherwise corresponds to that of the heat accumulator shown in FIG.

In contrast to a heat storage in the form of a container, it is possible with a cavity 49 in the ground 51 to realize much greater heights of the memory. As a result, with an equal amount of heat storage medium, the diameter can be reduced, so that the temperature boundary layer is reduced. This makes it possible to operate the heat storage for a long period of time, without a complete temperature compensation takes place by heat conduction. This is particularly possible because the soil can absorb much greater pressure forces than a conventional container wall 5 made of steel. In order to avoid that substances contained in the cavity 49, which serve as a heat storage medium, dissolve substances from the soil 51 and optionally react with the liquid to form undesired products, the cavity 49, like the container shown in FIG. 1, has an internal insulation 19 disguised. The structure of the inner insulation 19 is substantially the same as that shown in Figures 3 and 5.

Another possibility for a construction of an internal insulation 19 in a cavity in the ground 51 is shown in FIG. The inner insulation 19 also comprises a first insulating layer 41 in the embodiment shown in FIG and a second insulating layer 43. The second insulating layer 43 is preferably self-supporting and comes into contact with the liquid 7 contained in the cavity 49. The second insulation 43 is this layered, for example, of cuboidal elements. The first insulating layer 41 serves as additional insulation and is made, for example, of a material which can bear pressure, so that the second insulating layer 43 is pressed against the first insulating layer 41 due to the pressure of the liquid contained in the cavity 49 the forces acting thereby are carried by the first insulating layer 41. The first insulating layer 41 may be formed of glass foam or insulating stones, for example.

It is preferred if passages 57 are formed in the inner insulation 19. The passages 57 serve as relief leaks through which the liquid can flow behind the internal insulation 19.

The passages 57 are thereby designed so that a convective flow is avoided, so that once fluid flows through the passages 57 and, for example, in cavities 59, which are located behind the inner insulation 19, flows and fills them. If the liquid contained in the cavity 49 is sulfur, it cools in the cavities 59 and solidifies, whereby the inner insulation 19 is supported by back pressure. In order to ensure a continuous pressure equalization, it is advantageous if the temperature at the passages 57 always remains so high that the sulfur does not solidify but continues to exist as a melt. For this purpose, it is possible, for example, to provide temperature sensors with which the temperature is measured. If the temperature decreases too much, it is then possible, for example, to melt the solidified sulfur again by using suitable heating elements. Accordingly, the same applies to the use of, for example, salt melts, which should also be kept in the liquid state in the region of the passages 57 and then, for example, can be heated in the event of an excessive temperature decrease in order to liquefy them again. In order to realize very large heat storage with a correspondingly large cross-sectional area, it is possible to provide storage networks with internal walls. Such is exemplified in Figure 8. By using a storage network, it is possible to keep the span of a container roof in statically realizable sizes. The cavity 49 is used to generate the memory Federal divided by internal insulation 19 into individual individual memory 61. In each case the same liquid is contained in the individual storage, for example a sulfur melt. The respective individual storage, which are separated by the internal insulation 19 from each other, are advantageously connected hydrostatically with bushings. This makes it possible to keep the liquid level in the individual individual memories 61 uniform.

FIG. 9 shows a flange connection with internal insulation.

In order to be able to supply or remove liquid into the container, it is necessary to connect lines to the container. The connection with lines usually takes place by means of suitable flanges. Such a flange connection is shown by way of example in FIG. For this purpose, a flange 63 is formed on the container 3. A conduit 65 is connected to a second flange 67. The second flange 67 is partially designed concentrically around the conduit 65, wherein between the flange 67 and the conduit 65 insulating material 69 is added. At the same time located between the first flange 63 on the container 3 and the second flange 67, the inner insulation 19. By this design, a uniform insulation is achieved in the region of the flange. The connection of first flange 62 and second flange 67 is accomplished by conventional joining means, e.g. by means of screws 71. In addition, a sealing element is usually positioned between the first flange 63 and the second flange 67. A flap in a duct, which is designed with an inner insulation, is shown in FIG.

In order to protect especially lines through which the hot, corrosive liquid flows, from corrosion, it is also possible to provide the lines also with an internal insulation 19. To control the flow, it is possible, for example, to use fittings. Such fittings are, for example, flaps 73. In the area of the flap 73, the internal insulation 19 is interrupted, wherein a stop 75 is located in the region of the interruption. In order to close the line 65, the flap 73 can be placed so that it abuts against the stop 75. By rotation of the flap 73, the line 65 can be opened. The use of the internal insulation 19 prevents the hot material flowing through the conduit 65 from coming into direct contact with the material of the conduit 65. To protect the stopper 75 and the flap 73 are these are preferably provided with a high-temperature and corrosion-resistant coating 77.

Through the internal insulation 19 both in pipes and fittings as well as in the container can be designed a system that is operated with hot, corrosive liquids. Such a plant is for example a solar power plant, for example a parabolic trough solar power plant.

Examples

example 1

In a container with internal insulation is sulfur with a temperature of 390 ° C. The container has an internal insulation 19 made of refractory bricks. The container wall is made of steel. On the outside, the steel is enclosed by a mineral wool outside insulation.

Table 1 shows the temperatures that occur at the transitions from brick to steel, steel to mineral wool and mineral wool to the environment.

Table 1: Temperature profile in a device according to the invention with internal insulation of refractory bricks

From the temperature profile, it can be seen that the temperature decreases 154 ° C from the inside of the refractory bricks to the outside of the refractory bricks. The temperature at which the melt possibly passing through the refractory bricks comes into contact with the steel container wall is therefore 236.41 ° C. this is a Temperature at which most steels are corrosion resistant to sulfur and sulfur contained additives. Corrosion therefore does not occur.

Example 2

Considered is a structure in which hot sulfur with a temperature of 390 ° C comes into contact with the internal insulation. The internal insulation consists of a layer of refractory bricks and a layer of glass foam, which adjoins the refractory bricks. Between the glass foam layer and the steel container wall is a gap into which sulfur has flowed.

The temperatures on the outside of the individual layers are listed in Table 2.

Table 2: Temperature profile in a device according to the invention with two insulating layers

The additional layer of glass foam, preferably made of borosilicate glass or quartz glass, which is introduced between the container wall of steel and the refractory bricks, the temperature is reduced to the wall of steel so far that it has only 30 ° C. Corrosion on the steel shell at this temperature is no longer expected. The sulfur, which is between the glass foam and the steel container wall, is solid.

In addition, no external insulation is necessary because the temperature of the container wall made of steel is already so low that there is no danger in contact.

LIST OF REFERENCE NUMBERS

1 layer memory 41 first insulating layer

3 container 25 43 second insulating layer

5 container wall 45 external insulation

7 liquid 47 sheet

9 Container lid 49 cavity

1 1 further lid 51 soil

13 Compensation area 30 53 first inlet

15 first distributor 55 second inlet

17 second manifold 57 passage

19 internal insulation 59 cavity

21 wall 61 single memory

23 cuboid element 35 63 flange

25 gap 65 line

27 insulation board 67 second flange

29 wall hooks 69 insulating material

31 corrosion-resistant coating 71 screw

33 Container lid 40 73 Flap

35 insulating element 75 stop

37 hooks 77 high temperature and corrosion

39 corrosion-resistant seal solid coating

Claims

claims

Device for receiving hot, corrosive liquids (7), comprising a wall (21) enclosed space for receiving the liquid (7), characterized in that the space has an internal insulation (19).

Device according to claim 1, characterized in that the internal insulation (19) has passages (25, 57) through which the liquid (7) to be stored in the room can flow.

Device according to claim 1 or 2, characterized in that the internal insulation (19) is self-supporting.

Device according to claim 1 or 2, characterized in that the internal insulation (19) is made up of individual elements (27) fixed to the wall (21) of the enclosed space.

Device according to one of claims 1 to 4, characterized in that the inner insulation (19) consists of substantially cuboidal elements (23) is constructed.

Device according to claim 5, characterized in that the passages are gaps (25) between the parallelepiped elements (23).

Device according to one of claims 1 to 6, characterized in that the internal insulation (19) of a first insulating layer (41) and a subsequent to the first insulating layer second insulating layer (43) is constructed.

Device according to one of claims 1 to 7, characterized in that between the inner insulation (19) and the wall (21) a seal (39) is received from a corrosion-resistant metal.

Device according to one of claims 1 to 8, characterized in that the material of the inner insulation (19) alumina, silicon carbide, silica, aluminum foam, glass foam or a mixture thereof.

10. Device according to one of claims 1 to 9, characterized gekennnzeichnet that with a wall (21) enclosed space for receiving the liquid (7) is a container (3).

1 1. A device according to claim 10, characterized in that the wall (21) of the container (3) is made of steel or stainless steel.

12. The device according to claim 10 or 11, characterized in that the container (3) with a container lid (11) is closed and the Behälterde- disgust (11) insulating elements (35) are attached.

13. Device according to one of claims 1 to 9, characterized in that the liquid (7) receiving the enclosed space is a cavity (49) in the soil (51).

14. Use of the device for storing corrosive liquids according to any one of claims 1 to 13 for storing a sulfur-containing heat storage medium.