RU2669218C1 - Heat hydro insulation pipeline products for high-temperature thermal networks, heat and technological pipelines and the method of its manufacture - Google Patents

Abstract

FIELD: manufacturing technology.SUBSTANCE: invention relates to thermally insulated pipes and shaped products with thermal insulation based on polyurethane foam for underground and aboveground laying of heat networks, heating mains and process pipelines operated at a coolant temperature of more than 130 °C. Heat hydro insulation pipeline article and the method of its manufacture contain a pipeline element and successively located above it thermal insulation and waterproofing. Thermal insulation contains a layer of high-temperature thermal insulation on the surface of the pipeline element made of a material based on airgel of silicon dioxide and above it a layer of thermal insulation made of polyurethane foam with temperature at the interface between the layer of high-temperature thermal insulation – the layer of insulation made of polyurethane foam is not more than 130 °C.EFFECT: technical result is an increase in the operational properties and reliability of the use of thermally insulated pipeline products.42 cl, 12 dwg, 3 tbl

Description

Technical field

The invention relates to thermally-insulated pipes and fittings with thermal insulation based on polyurethane foam, intended for underground and above-ground installation of heating networks, heating mains and process pipelines operated at a coolant temperature of more than 130 ° C.

State of the art

In the heat and power industry, when laying heating networks, heating mains and technological pipelines, steel pipes with a diameter of 25 to 1420 mm and the corresponding shaped products with thermal insulation made of polyurethane foam (PPU) and waterproofing in the form of a polyethylene sheath for underground laying in a channelless way or in the form of a sheath of sheet galvanized steel during overhead installation, as well as when laying in passageways and tunnels.

The use of steel pipes and fittings with thermal insulation made of polyurethane foam can significantly reduce heat loss while reducing operating costs.

Polyurethane foam has a low coefficient of thermal conductivity (0.029-0.033 W / m ° C) and provides a design durability of at least 30 years.

However, thermal insulation with polyurethane foam can be used at a temperature of not more than 140 ° C (short-term up to 150 ° C), since at a higher temperature it is destroyed with the loss of heat-insulating properties. This significantly limits the scope of its application.

There are known examples of the use of heat-insulated mineral wool in heat-insulated piping elements operated at elevated temperatures of the coolant (more than 140 ° C).

Known heat-insulated pipe, consisting of placed on the pipe heat-insulating coating containing heat-reflecting and heat-insulating layers. The heat-insulating coating comprises a layer of a basalt sheet wound on a pipe coated with a heat-reflecting layer, an outer protective layer and a second heat-reflecting layer. A heat-insulating layer is placed between the heat-reflecting layers, and a protective outer layer is placed on the outer heat-reflecting layer. The heat-insulated pipe is made mainly of metal, for example, 12Kh1MF steel. The heat-insulating coating of the pipe is multilayer. A layer of thin basalt fabric is wound on the pipe surface, on which a layer of heat-reflecting material, for example, a thin foil, preferably aluminum, is applied, on which a layer of heat-insulating material, for example, felt, is closed, which is covered with a layer of heat-reflecting material (second layer), for example, foil, preferably aluminum, on which a fiberglass layer can be laid, on which a protective layer is placed, which is, for example, a plastic pipe [RU No. 121855, ЕВВ 17/00, F16L 59/00, 10.11.2012].

The disadvantages of RU No. 121855 are the high value of the thermal conductivity λ for the materials used (λ about 0.1 W / (m⋅ ° C), at a temperature of 250 ° C), which leads to significant heat losses, and the production technology requires multiple sequential operations for the formation of this design of thermal insulation, which requires the involvement of large production facilities and technological equipment. A significant disadvantage of RU No. 121855 is also the impossibility of obtaining a complete waterproofing product due to the lack of adhesion of the fiberglass layer to the waterproofing sheath.

The use of mineral heat-insulating materials with heat resistance of more than 150 ° C due to the high value of the coefficient of thermal conductivity leads to the necessity of forming a heat-insulating layer of large thickness, and the absence of a mechanized method of applying a waterproofing sheath made of polyethylene or galvanized steel sheet tightly adjacent to the insulation surfaces, as well as technological and operational problems significantly increase the cost of manufacture, reduce the life of the products.

Known examples of the use in thermally-insulated pipe elements operated at elevated coolant temperatures (more than 140 ° C) of a combined two-layer thermal insulation based on mineral wool and polyurethane foam, in which the first, so-called “barrier” layer of high-temperature combined thermal insulation provides a decrease in temperature at the border section high-temperature insulation / polyurethane foam to the desired value of 120-140 ° C.

A known method of manufacturing pipes with combined thermal insulation for elevated heating mains, which consists in the fact that to improve the performance of pipes with combined thermal insulation, the outer surface of the steel pipe is pre-cleaned of contaminants and layers of corrosion, then the first layer of thermal insulation is applied, consisting of basalt mineral wool rocks with pre-inserted centering elements, the height of which is equal to the thickness of the first heat-insulating layer, and placed in a spiral a twisted shell made of thin galvanized steel, after which the annular gap between the inner surface of the shell and the outer surface of the first insulation layer is sealed with flanges on both sides and the gap is filled with rigid polyurethane foam through the injection hole on the flange. At the same time, the first heat-insulating layer, consisting of basalt rock shells laminated with aluminum foil, made with U-shaped castle joints along the length and ends of the mineral wool, protrudes from thermal insulation, consisting of rigid polyurethane foam for a length of 5 to 25 mm on each side of the pipe with combined thermal insulation [RU 2611925, F16L 9/14, F16L 59/14, publ. 03/01/2017].

Also known is a heat-insulated heating element for laying underground heating pipelines transporting hot steam and viscous combustible liquids in a single combined insulation, which, to increase the energy efficiency of the heating element, contains a pipeline with thermal insulation and an external protective sheath, and the pipeline consists of three tightly adjacent to each other and fastened between a steel tape of steel pipes intended for supplying heating steam through one of them and for pumping along the other two forward and reverse directions, respectively, viscous flammable liquid. Thermal insulation is made of a combination of one-sided non-foamed mineral wool, on the surface of which centering rings are installed, and a layer of polyurethane foam filling the internal space between the protective shell and mineral wool, the mineral wool having a density of 90-110 kg / m ³ and reinforced with a steel mesh with thermal conductivity mineral wool with steel mesh 0,046-0,050 W / m ° C, and the protective sheath is made of solid polyethylene [RU 153030, F16L 53/00, F16L 59/14, F17D 1/18, Publ. 06/27/2015].

A common disadvantage of RU 2611925 and RU 153030 is the use of mineral wool with a high coefficient of thermal conductivity, which leads to significant heat loss or a significant increase in the diameter of the insulated structure and, accordingly, to an increased cost of manufacturing and use of such products.

Known steel heat-insulated pipe element for above-ground heating mains, allowing its operation at elevated coolant temperatures (above 130 ° C to 200 ° C) with an increased service life due to an increase in the adhesive strength during shear in the axial and tangential directions and reducing the likelihood of corrosion processes on the surface steel pipe elements containing a steel pipe element, thermal insulation and a waterproofing spiral-wound sheath made of galvanized sheet steel. The thermal insulation is double-layer, while the inner thermal insulation layer is 3.5-5.0 mm thick and is formed by a liquid-ceramic coating, including glass microspheres, mineral fillers, expanded perlite, volostanite and a binder - styrene-butadiene latex with heat resistance of 200 ° C, thermal conductivity at 50 ° From 0.021 W / m ° C, and the outer layer of thermal insulation is made of rigid polyurethane foam with a density of 75-80 kg / m ³ and thermal conductivity of 0.03 W / m ° C, and centering rings are installed on the inner layer of insulation, forming a ring An end gap between the last and the waterproofing spiral sheath, which is filled with a rigid polyurethane foam forming the outer layer of thermal insulation, the inner thermal insulation layer is applied to the outer active phosphated surface of the steel pipe element, obtained after cleaning from rust, scale and fat deposits and simultaneous treatment with a phosphating modifier with a rust converter and the inner surface of the shell is treated with a phosphating modifier, including a rust converter and anti-corrosive film former [RU 49167 F16L 9/14, Publ. November 10, 2005].

A low coefficient of thermal conductivity (0.01-0.02 W / m ° C) of liquid ceramic insulation RU 49167 is declared, but not experimentally confirmed. The layer of the proposed liquid-ceramic insulation with a thickness of 3.5-5.0 mm is not physically able to provide a temperature at the boundary of the "barrier" layer / PUF below 140 ° C at a coolant temperature of 200 ° C.

In addition, RU 49167 also states that the process of applying and drying a liquid-ceramic coating is extremely time-consuming and time-consuming due to the need to apply at least 3 coating layers with a thickness of 0.3-1.5 mm, which increases the duration of the process by more than an order of magnitude and significantly increases the cost of production.

Known liquid-ceramic heat-insulating materials with heat resistance of 200-250 ° C and having experimentally not confirmed thermal conductivity (0.01-0.02 W / m ° C) cannot be widely used in heating networks without a combination with other heat-insulating elements due to the need to set the total required thickness of the insulating layer 25-30 mm in separate layers from 0.3-0.4 mm to 1.0-1.5 mm thick with a long drying time between the applied layers, which is practically impossible in real production conditions and dramatically increases the cost st cost of products with liquid ceramic insulation.

There are known examples of improving the quality of thermal waterproofing of pipes during operation and the reduction of heat losses as a result of the formation of additional layers based on mineral materials on the surface of the waterproofing layer.

Known heat-insulated pipe designed for heating networks, which to maintain the quality of the pipe insulation during operation and reduce heat losses as a result, contains a metal pipe, a layer of thermal insulation coating made of polyurethane foam and an outer shell in the form of a pipe made of low pressure polyethylene, on the inner surface of which an additional layer is applied based on a polyolefin with the addition of a mineral filler with the content of its constituents in the following ratio, al. %: mineral filler - 20-70, polyolefin - the rest [RU 159836, F16L 59/02, Publ. 02/20/2016].

Known heat-insulated pipe designed for heating networks, which to maintain the quality of the pipe insulation during operation and to reduce heat losses as a result, contains a metal pipe, a layer of thermal insulation coating made of polyurethane foam and an outer shell in the form of a pipe made of low pressure polyethylene, and in which the inner surface the outer polyethylene sheath of the pipe applied an additional layer based on a polyolefin with the addition of mineral filler and a foaming additive with holding its constituent components in the following ratio, wt. %: mineral filler - 20-70, blowing agent - 1-5, polyolefin - the rest [RU 159805, F16L 59/00, Publ. 02/20/2016].

The disadvantages of RU 159836 and RU 159805 are that an additional polyolefin-based layer with the addition of mineral additives is applied to the inner surface of the outer polyethylene waterproofing sheath, therefore, the PUF-based heat-insulating layer adheres directly to the steel pipe, that is, the temperature of the heat carrier cannot be used to implement these solutions to be higher than 130-140 ° C.

Known heat-insulated pipe is intended for heating networks, which, to maintain the quality of the pipe insulation during operation and to reduce heat losses as a result, contains a metal pipe, a layer of thermal insulation coating made of polyurethane foam and an outer shell in the form of a pipe made of low-pressure polyethylene, on the inner surface of the outer shell of which is applied an additional layer of sevilen with ethylene vinyl acetate [RU 147207, F16L 59/02, Publ. 10.27.2014] - in this case, the adhesion of the PUF to the PE shell is obviously improved, but the temperature of the coolant cannot be more than 130-140 ° С.

It is known to use mullite-siliceous roll felt MKRV-200 GOST 23619-79 as thermal insulation in heat-insulated pipes.

Felt MKRV-200 is a mullite-siliceous roll heat-insulating material, which has high strength, flexibility and elasticity with a high fire resistance. For the manufacture of this product, mullite-siliceous fibers are used, made from pure silicon and aluminum oxides by melting in a high-temperature electric furnace and then blowing the fibers. In order to give the material maximum elasticity and strength, binders are used, which are added to the fibers during the manufacturing process. Due to the properties of the fiber, this heat-insulating material has the highest chemical resistance to various alkalis and acids, but in high temperature conditions it is necessary to prevent concentrated alkalis, as well as phosphoric and hydrofluoric acids from acting on the felt.

The disadvantage of mullite-siliceous roll felt MKRV-200 GOST 23619-79 is the relatively high coefficient of thermal conductivity of felt MKRV-200 - 0.039 W / m * ° C (at 25 ° C) and 0.127 W / m * ° C (at 300 ° C), practically corresponding to the coefficient of thermal conductivity of mineral wool, which leads to an inevitable increase in the required thickness of thermal insulation and the diameter of the insulated structure.

Heat-insulating materials based on silicon dioxide airgel are known, however, no examples of thermal hydro-insulation of pipeline products with combined insulation and a “barrier” high-temperature layer based on silicon dioxide airgel were found in the scope of the search.

Known composite material with porosity above 60% and with a density below 0.6 g / cm ³ containing airgel and fibers distributed therein. The airgel includes cracks and fragments of airgel surrounded by cracks, the average volume of which is from 0.001 cm ³ to 1 cm ³ connected by fibers. The composite material is obtained by mixing the sol with the fibers, converting the sol into a gel, deforming the gel to crack, drying the gel to obtain an airgel [RU 2146662 С04В 30/02, С04В 38/00, С04В 35/14 Publ. 03.20.2000, Conv. Priority 08.29.1994 DE P 4430642.3].

Known mineral wool composite containing mineral wool fibers, a binder component and airgel material. The airgel material contains a fibrous component and an airgel component, wherein the amount of the airgel component is from 10% to 40%. Mineral melt is fed into a fiberising device, which contains at least two or more fiberising rotors rotating around a horizontal axis. The fibers are blown away from the sheath surfaces of the rotors of the fiberising device to a collecting means located at a distance from the fiberising device. The airgel material is added to the mass of freshly prepared fibers formed on the surfaces of the sheath by means of adding airgel material located on the side of the binder. The binder component is added by means of adding a binder located in the immediate vicinity of the purge means [RU 2469967 С03С 13/06, С03В 37/05 Publ. 12/20/2012 Conv. Priority 12/23/2009 FI 20096391].

The disadvantages of RU 2146662 and RU 2469967 are the production of composite material in the form of a mat and the inability to use it in an industrial environment in the form of a web for thermal insulation of pipeline products, as well as the inability to use it as thermal insulation for underground and above-ground laying of heating networks and technological pipelines, for which it is mandatory it is necessary to have a waterproofing structure.

Known foamed silica gel, the use of foamed silica gel as a fire extinguishing agent and sol-gel, the method of its preparation for its subsequent use in explosion and fire prevention, as well as an insulating and filling material in construction and in other industries. Foamed silica gel is obtained by air-mechanical foaming of a mixture of an aqueous solution of alkali metal silicate with a foaming surfactant and an aqueous solution of silica activating ash formation from alkali metal silicate in the form of an aqueous solution of acetic acid, hydrochloric acid or ammonium chloride [RU 2590379 C01B 33/16 Opub . 07/10/2016].

Known heat-insulating material, which is obtained from a mixture of at least the following components, which are: water-based foam, particles of silicon dioxide airgel, at least one binder selected from an organic binder and an inorganic binder, at least one cationic salt a surfactant compound and at least one salt of an anionic surfactant compound [RU 2585645 C08J 9/00 Publ. 05/27/2016 PCT WO 2011/095745 (08/11/2011)].

The disadvantages of RU 2590379 and RU 2585645 are its production in the form of brittle foam and the inability to use it in an industrial environment in the form of a web for thermal insulation of pipeline products.

Tubular elements with thermal insulation based on silicon dioxide airgel are known, however, no examples of thermal waterproofing of pipeline products with combined insulation and a “barrier” high-temperature layer based on silicon dioxide airgel were found in the scope of the search.

Known used for thermal insulation of pipelines is a tubular insulating lining for flexible pipes of various diameters with the possibility of winding them on a bobbin or reel to improve convenience during storage and transportation, containing a tubular element, an insulating layer and an outer protective sheath. The tubular element is elastically deformable in the radial direction and is adapted to accommodate the underlying pipe lining, consistent with it in size or geometrically, or for compression during storage. The insulating layer is made on the basis of airgel and is positioned so as to surround an elastically deformable tubular element with play. The outer protective sheath is arranged to enclose an insulating layer. [RU 2605485 F16L 59/14, publ. 12/20/2016, PCT Application IB 2011/055216 (11/21/2011), Publication of the PCT Application WO 2012/069982 (05/31/2012)].

A known method of manufacturing a pipe section of mineral wool, in which: saw off a thin strip from an untreated plate of mineral wool; cut off the specified strip in length in accordance with a given wall thickness of the manufactured section; wrap the strip on the rod to obtain a multilayer cylinder; place the core with the mineral wool cylinder wound thereon into the molding device and process it. Before winding the strip on the rod and / or while winding the strip on the rod between the layers of mineral wool, a granular material is applied having improved thermal insulation. The technical result of the invention is the simplicity of manufacturing the pipe section and the improvement of its heat-insulating ability. [RU 2540128 F16L 59/04, F16L 59/14, Publ. 02/10/2015, Conv. priority: 06.16.2010 FI 20105695].

A common disadvantage of RU 2605485 and RU 2540128 is the lack of a waterproofing sheath and, as a consequence, the inability to use heating and technological pipelines for underground and above-ground laying.

The closest in technical essence and the achieved technical result (prototype) is a thermally insulated pipe product and a method of its manufacture for laying above-ground heating mains operated at a constant heat carrier temperature of 150 ° C and higher, according to which to increase the maximum permissible heat carrier temperature from 130 ° C to 150 -200 ° С, increasing reliability during long-term operation of the heating main as a whole and increasing the service life of thermally insulated pipe elements, the pipe element covers the heat insulation and waterproofing spiral sheath made of galvanized sheet steel, the outer surface of the tube element is pre-cleaned of contaminants and layers of corrosion and simultaneously treated with a phosphating modifier that includes a rust converter and an anti-corrosion film former, and thus form a phosphating coating, then apply the first thermal insulation layer consisting of foil mineral basalt wool with the fibers of the lamellar type density 40-45 kg / m ^3, a thickness of 40-50 m, comprising 45-55% (vol.) of the total volume of thermal insulation, and thermal conductivity at 50 ° C 0.05 W / m⋅ ° C, then centering rings are installed on the obtained foil surface and the tube element with centering rings is placed in a spiral sheath from a galvanized steel sheet, the inner surface of the shell being pre-cleaned of contaminants by treating it with a phosphating modifier, including a rust converter and an anti-corrosion film former, by means of the latter they form a film e coating, then the annular gap between the inner surface of the shell and the outer surface of the first thermal insulation layer of foiled mineral basalt wool is sealed with flanges on both sides of the waterproofing shell and the gap is filled through the injection hole on the flange with rigid polyurethane foam with a density of 75-80 kg / m ³ and thermal conductivity at 50 ° C 0.03 W / m⋅ ° C, comprising 45-55% (volume.) Of the total volume of thermal insulation [RU 2278316, F16L59 / 02, F16L59 / 10, publ. 06/20/2006 (prototype)].

Identified during thermal insulation of pipe products in real production conditions, the disadvantages of RU No. 2278316 (prototype) are that

- when filling the annular gap between the surface of the first high-temperature layer of thermal insulation based on mineral basalt wool and the waterproofing membrane with foamed polyurethane foam during the structuring of the polyurethane foam during the formation of the second layer of thermal insulation creates a relatively high pressure (1.2-1.3 kgf / cm ² ), which leads to compaction of a layer of mineral basalt wool, the thickness of which as a result of compaction decreases by 30-40%, its density and thermal conductivity respectively increase, which in the final result leads to an increase in heat loss during transportation of the coolant;

- the thickness of the first high-temperature layer of thermal insulation based on mineral basalt wool in the design should be calculated not only on the basis of the temperature of the coolant, but also taking into account its compaction during pouring. Therefore, the use of mineral wool as the first high-temperature layer of thermal insulation based on mineral basalt wool leads to a significant increase in the diameter of the final product, a thermally insulated pipe.

- when a thermal insulation layer of foil mineral basalt wool with lamellar type is applied to the steel pipe, the joints of the joints of mineral basalt wool are not sealed to each other, therefore, during the process of structuring the foamed polyurethane foam and creating pressure in the internal sealed volume at the joints of the sheets of mineral basalt wool, gaps are formed filled with foamed polyurethane foam, which during continuous operation above 130 ° C burns out and forms a thermal "bridge", contributing to loss of thermal energy of the coolant;

- centering rings mounted on the surface of the heat-insulating layer of foil mineral wool with lamella type fibers when it is sealed during pouring with polyurethane foam under the weight of the pipeline element inevitably shift, which leads to a violation of the alignment of the structure. Deviation of the axial line of the pipeline element from the axis of the waterproofing shell negatively affects the quality of welding during the installation of the thermally insulated pipeline, as well as the quality of the insulation of the butt joints of pipes and fittings.

The thermal conductivity coefficient of mineral wool at a temperature of 200 ° C is 0.08 W / m ° C, and at a temperature of 250 ° C it is 0.1 W / m ° C, which leads to a large required thickness of high-temperature thermal insulation with mineral wool, which, in turn, , leads to the need for a significant increase in the outer diameter of insulated products and, accordingly, to increase the complexity and cost of their manufacture, installation and operation.

Technical Problem and Technical Result

An urgent problem in the field of heat power engineering is the need for reliable and durable heat and water insulation of underground and elevated pipelines of heating networks, heating mains and process pipelines used in the transportation of heat carriers with temperatures from 130 to 250 ° C and above.

For thermal insulation of pipes and fittings used in the construction and operation of heating networks, heating mains and technological pipelines, rigid polyurethane foam is widely used, the coefficient of thermal conductivity of which is 0.029 - 0.033 W / m ° С.

The advantage of rigid polyurethane foam is its good adhesion to the surface of the waterproofing membrane (polyethylene or galvanized sheet steel), which ensures the integrity of the structure and, accordingly, reliable waterproofing of the structure.

However, at temperatures above 130 ° C, the destruction of polyurethane foam begins and it sharply loses its strength and thermal insulation properties. Therefore, polyurethane foam can only be operated at temperatures no higher than 130 ° C, which greatly limits its application.

Mineral wool thermal insulation can be used at coolant temperatures up to 300 ° С and higher, but mineral wool thermal insulation does not adhere to the waterproofing shell, which does not allow for reliable waterproofing of structures.

Due to the high hygroscopicity of mineral wool, it is not used for thermal insulation of heat pipes for underground installation, since wetting of thermal insulation from mineral wool leads to large heat losses.

When installing above ground, a waterproofing shell made of galvanized sheet steel is used, which does not always provide reliable waterproofing, which can also lead to wetting of mineral wool and heat loss.

In well-known structures with combined thermal insulation, mineral wool / polyurethane foam adhesion to the waterproofing membrane is provided by a thermal insulation layer of polyurethane foam, which allows reliable waterproofing of the product.

In cases where the heat carrier temperature is higher than 130 ° C, the use of combined thermal insulation is required to prevent the polyurethane foam from heating above the maximum permissible temperature by forming the first, so-called “barrier” layer of high-temperature thermal insulation, which allows to reduce the temperature at the high-temperature thermal insulation / polyurethane foam interface to the required value ( no more than 130 ° C).

Mineral fiber materials commonly used for combined thermal insulation (fiberglass, basalt fiber, mineral wool, mullite-siliceous felt, etc.) have a relatively high coefficient of thermal conductivity and are able to provide thermal insulation only with a large thickness of the thermal insulation layer, which leads to a significant increase in the diameter of thermal insulation and accordingly, a significant increase in the dimensions of thermally insulated products and the complexity of their manufacture, a significant rise in price construction and installation works during the laying and operation of thermal communications.

Calculations show that the required thickness of the “barrier” layer of high-temperature mineral wool thermal insulation in the construction of combined insulation (mineral wool + polyurethane foam) for a steel pipe with a diameter of 325 mm, at a coolant temperature of 250 ° C with a temperature gradient of 250-130 = 120 required for high-temperature thermal insulation ° C is 170 mm, and the diameter of the waterproofing shell of this design will be - 710 mm.

The objective of the claimed technical solution is to eliminate the above disadvantages of the known analogues and prototype.

The technical results achieved during the implementation and industrial use of the invention are to increase the operational properties and reliability of the use of thermo-insulated pipeline products intended for underground and above-ground installation of heating networks, heating pipelines and process pipelines operated at a coolant temperature of more than 130 ° C.

SUMMARY OF THE INVENTION

The technical problem is solved, and the technical result is achieved by the fact that in a thermally insulated pipeline product for high-temperature heating networks, heating pipelines and process pipelines containing a pipeline element and heat insulation and waterproofing sequentially arranged above it, according to the invention, the thermal insulation comprises a layer of high temperature thermal insulation from silica airgel-based material and a layer of t ploizolyatsii polyurethane foam ensuring the temperature at the interface of high-temperature insulation layer - insulation layer of polyurethane foam is not more than 130 ° C.

Moreover, the high-temperature thermal insulation layer containing silicon dioxide aerogel has a thermal conductivity coefficient of not more than 0.022 W / (m * ° C) at 25 ° C and not more than 0.035 W / (m * ° C) at 260 ° C, and the thermal insulation layer of polyurethane foam contains a rigid polyurethane foam with a density of at least 60 kg / m ³ and with a thermal conductivity coefficient at 50 ° C of not more than 0.033 W / (m * ° C).

The high-temperature thermal insulation layer in the product is mainly made of a non-woven fabric with silicon dioxide airgel particles distributed thereon, applied to the pipe element by spiral winding or longitudinal laying in several layers on top of each other with mutual overlapping of joints and a possible intermediate coating of layers and joints of the fabric with heat-reflecting material, for example , thin aluminum foil or metallized aluminum foil tape.

In the product, centering supports are installed on the surface of the high-temperature thermal insulation layer with the possibility of alignment of the pipeline element with the layer of high-temperature thermal insulation and waterproofing in the form of a polyethylene or steel waterproofing sheath.

Under the centering supports are ring substrates of non-woven fabric with silicon dioxide airgel particles distributed in it, with the possibility of sealing the high-temperature thermal insulation layer by 10-20% and preventing the alignment of the centering supports, preserving the alignment of the structural elements and tight fitting of the centering supports to the waterproofing shell.

The ring substrates located on the outside of the high-temperature thermal insulation layer under the centering supports can be reinforced with heat-reflecting material, for example, thin aluminum foil or metallized aluminum foil with adhesive tape.

A thermally insulated pipeline product may contain a pipeline element with a diameter of 25 to 1420 mm and can be made in the form of a thermally insulated pipe or in the form of a thermally insulated shaped pipe element in the form of a branch, tee, transition between pipelines of various diameters or Z-shaped, L-shaped, Y- shaped, L-shaped, U-shaped thermally insulated shaped element.

The outer surface of the steel pipe element is pre-cleaned from rust and treated with a high-temperature-resistant anti-corrosion coating, preferably containing a suspension of aluminum powder and target additives in a modified silicone film-forming compound, for example, heat-resistant enamel KO 8104 silver-gray grade TU 2312-421- 05763441-2003.

A thermally insulated pipeline product can be designed for laying underground heating networks, heating mains and technological pipelines and made with waterproofing in the form of a waterproofing shell made of low pressure polyethylene or in the form of a waterproofing shell made of low pressure polyethylene with a corona treated inner surface to increase the adhesion of polyurethane foam to polyethylene or can be made intended for laying above-ground heating networks, heat races and process piping and manufactured with a waterproofing membrane in the form of waterproofing helicallywound galvanized steel sheet or as a waterproofing membrane helicallywound of galvanized steel sheet treated with a phosphating modifier and the anticorrosion film former inner surface to increase the adhesion of polyurethane foam to the galvanized steel.

The technical problem is solved, and the technical result is also achieved by the fact that in the manufacture of a thermally insulated pipeline product for high-temperature heating pipelines and process pipelines, including the production of heat insulation and waterproofing sequentially located above it on the pipeline element, according to the invention, the thermal insulation is made in the form of a high-temperature layer located on the surface of the pipeline element thermal insulation based on silica airgel and false over it a layer of insulation foam with a temperature at the interface providing high temperature insulation layer - insulation layer of polyurethane foam is not more than 130 ° C.

At the same time, a high-temperature thermal insulation layer is made with a thermal conductivity coefficient of not more than 0.022 W / (m * ° C) at 25 ° C and not more than 0.035 W / (m * ° C) at 260 ° C, and a thermal insulation layer of polyurethane foam is made of rigid polyurethane foam with a density of at least 60 kg / m ³ and a thermal conductivity coefficient at 50 ° C of not more than 0.033 W / (m * ° C).

The high-temperature thermal insulation layer is made of a non-woven fabric with particles of silicon dioxide aerogel distributed in it, for example, of Pyrogel XT thermal insulation material (www.aerogel-russia.ru), which is a non-woven fabric with silicon dioxide aerogel particles distributed in them. The thermal conductivity of this material is not more than 0.022 W / (m * ° C) at 25 ° C and 0.035 W / (m * ° C) at 260 ° C.

Non-woven webs with silicon dioxide airgel particles distributed therein are laid on the surface of the product’s pipeline element by spiral winding or by longitudinal laying with several layers located one above the other with mutual overlapping of the web joints, with an intermediate coating of the layers and web joints with heat-reflecting material, for example, thin aluminum with foil or metallized aluminum foil with adhesive tape.

After the formation of the high-temperature thermal insulation layer by layers of a non-woven fabric with silicon dioxide airgel particles distributed in it, centering supports are installed on the surface of the high-temperature thermal insulation with ring substrates placed under them with the possibility of sealing by 10-20% of the high-temperature thermal insulation layer to prevent the centering supports from shifting, maintaining alignment and tightness the alignment of the centering supports to the waterproofing in the form of a waterproofing shell during the application of the second loya thermal insulation made of polyurethane foam.

At the same time, the ring substrates placed on the surface of the high-temperature insulation layer under the centering supports are made of a non-woven fabric with silicon dioxide airgel particles distributed in it and reinforced with heat-reflecting material, for example, thin aluminum foil or metallized aluminum foil with adhesive tape.

A thermo-insulated pipeline product of the design described above is made using steel pipeline elements with a diameter of 25 to 1420 mm in the form of thermally insulated pipes or in the form of thermally insulated pipe fittings in the form of bends, tees, transitions between pipelines of various diameters or Z-shaped, L-shaped, Y -shaped, L-shaped, U-shaped thermally hydroinsulated shaped elements.

In this case, the outer surface of the steel pipe element is preliminarily cleaned of rust and treated with a high-temperature-resistant anticorrosive coating, preferably containing a suspension of aluminum powder and target additives in a modified organosilicon film-forming compound, for example, heat-resistant enamel KO 8104 silver-gray grade TU 2312-421 -05763441-2003.

The product is made for underground heating pipelines and process pipelines with waterproofing in the form of a waterproofing sheath made of low pressure polyethylene or low pressure polyethylene waterproofing sheath with corona treated inner surface to increase the adhesion of polyurethane foam to polyethylene or the product is made designed for laying overhead heating pipelines and technological pipelines with waterproofing in the form of a waterproofing shell from a spiral Hovit galvanized steel sheet or waterproofing membranes helicallywound of galvanized steel sheet treated with a phosphating modifier and the anticorrosion film former inner surface to increase the adhesion of polyurethane foam to the galvanized steel.

To enable subsequent integration of the product into the heating main or technological pipeline with subsequent thermal insulation of the butt joints with connecting elements containing a layer of high-temperature insulation based on silicon dioxide airgel and a layer of thermal insulation made of polyurethane foam above it, a layer of high-temperature insulation based on silicon dioxide airgel along the end parts of the product in relation to the upstream insulation layer of polyurethane foam and hydro zolyatsii protruding not less than 100 mm.

Brief Description of the Drawings

The invention is illustrated by drawings, which shows the pipe element 1, a layer of high-temperature insulation 2 based on silicon dioxide airgel, waterproofing sheath 3, a layer of thermal insulation made of polyurethane foam 4, centering supports 5.

In FIG. 1 shows a cross section of a thermally insulated pipeline product for high-temperature heating networks, heating mains and technological pipelines, comprising a pipeline element 1 in the form of a steel pipe with a layer of high-temperature insulation 2 from a material based on silicon dioxide airgel, a waterproofing sheath 3, a layer of thermal insulation from polyurethane foam 4 and 5 centering supports .

In FIG. 2 is a cross-section of region A of a thermally insulated pipeline product for high-temperature heating networks, heating mains and technological pipelines with a pipe element 1 in the form of a steel pipe, on which a layer of high-temperature thermal insulation from a material based on silicon dioxide aerogel formed by several layers of a nonwoven fabric with distributed particles of airgel is shown silicon dioxide, located with the offset and overlap of the joints of the paintings.

In FIG. 3 is a cross-section of a thermally insulated pipeline product for high-temperature heating pipelines and technological pipelines, comprising a pipeline element 1 in the form of a steel pipe with section B, on which a layer of high-temperature thermal insulation 2 based on silicon dioxide aerogel is shown enlarged, formed by several layers of a nonwoven fabric with distributed particles of silicon dioxide aerogel located with the displacement of the joints of the paintings, the centering supports 5 and located under the centering supports annular masonry 6.

In FIG. 4 is a section B and a side view of a centering support mounted on a layer of high temperature insulation and made in the form of a stacked ring of individual fragments fastened to each other.

In FIG. 5 is a sectional view of an embodiment of a shaped article in the form of a branch, where a pipe element 1 is shown in the form of a steel pipe with a layer of high-temperature insulation 2 made of a material based on silicon dioxide airgel, a waterproofing sheath 3, a layer of thermal insulation made of polyurethane foam 4, centering supports 5 and a transition arcuate element 7 .

In FIG. 6 is a sectional view of a variant of a shaped article in the form of a tee.

In FIG. 7 is a sectional view of a variant of a shaped article in the form of a transition of pipelines of various diameters, where a piping element 1 is shown in the form of a transition of pipes of different diameters with a layer of high-temperature insulation 2 made of a material based on silicon dioxide airgel, waterproofing sheath 3, a layer of thermal insulation made of polyurethane foam 4, centering supports 5 and transition element 8.

In FIG. 8 is a sectional view of a variant of a shaped article in the form of a parallel tee, which shows a pipe element 1 with a layer of high-temperature insulation 2 made of a material based on silicon dioxide airgel, a waterproofing sheath 3, a layer of thermal insulation made of polyurethane foam 4, centering supports 5 and a transition arcuate element 7.

In FIG. 9 is a sectional view of an embodiment of an S-shaped shaped article, where a pipe element 1 with a layer of high-temperature thermal insulation 2 of a material based on silicon dioxide airgel, a waterproofing sheath 3, a thermal insulation layer of polyurethane foam 4, centering supports 5 and a transition arc-shaped element 7 is shown.

In FIG. 10 shows a sectional view of an embodiment of a shaped article in the form of a thermally-insulated ball valve 9.

In FIG. 11 is a structural cross-section of the butt joint of two products in a polyethylene waterproofing sheath, which shows the pipe elements 1, layers of high-temperature thermal insulation 2, waterproofing sheath 3, a thermal insulation layer of polyurethane foam 4, centering supports 5, an insert of high-temperature thermal insulation 10, heat-shrinkable sleeve 11, weld 13 .

In FIG. 12 is a diagram of the formation of a layer of high temperature insulation by spiral winding.

The implementation of the invention

In the patented heat-insulated pipeline product for high-temperature heating and technological pipelines, the first, so-called “barrier” layer of high-temperature thermal insulation made of a material based on silicon dioxide aerogel, for example, made of the material of thermal insulation Pyrogel XT (www.aerogel-russia.ru), is located on the pipeline element in the form of a non-woven fabric with particles of silicon dioxide airgel distributed in it, it allows to reduce the temperature at the interface of high-temperature thermal insulation / foam liuretan to acceptable values for the foam temperature not exceeding 130 ° C.

The new high-tech insulation material used to manufacture the high-temperature thermal insulation layer is characterized by higher efficiency compared to mineral wool, the thermal conductivity of the material based on silicon dioxide airgel is the lowest of all known thermal insulation materials, the thermal conductivity of this material is not more than 0.022 W / (m * ° С ) at 25 ° С and 0.035 W / (m * ° С) at 260 ° С.

Previously, such materials based on airgel were not used in the designs of thermal insulation of pipes and fittings for laying heating networks, heating mains and technological pipelines with thermal insulation from polyurethane foam.

The proposed heat-insulated pipeline product for high-temperature heating networks, heating mains and process pipelines contains a pipeline element and heat insulation and waterproofing sequentially located above it.

Thermal insulation contains a layer of high-temperature thermal insulation made of a material based on silicon dioxide airgel located on the surface of the pipeline element and a layer of polyurethane foam located above it.

The proposed heat-insulated pipeline product for high-temperature heating networks, heating mains and process pipelines is made as follows:

The outer surface of the pipeline element for a thermally insulated pipe and / or shaped product is pre-cleaned of contaminants and layers of corrosion to a degree of purification of 3 in accordance with GOST 9.402 on a specialized line with a high degree of automation using shot blasting machines.

To provide reliable protection against corrosion processes in the event of condensation, a high-temperature-resistant anticorrosion coating is applied to the surface of the tube element, preferably a suspension of aluminum powder and target additives in a modified silicone film-forming compound, for example, heat-resistant enamel KO 8104 silver-gray grade B TU 2312-421-05763441-2003.

On the outer surface of a similarly prepared pipeline element with an anti-corrosion coating, layers of high-temperature thermal insulation are formed from a material based on silicon dioxide airgel, mainly by means of a nonwoven fabric with a thickness of 3 to 10 mm with silicon dioxide airgel particles distributed in it.

It was experimentally established that to ensure effective thermal insulation, the density of such a layer of high-temperature thermal insulation should preferably be at least 120 kg / m ³ .

The total thickness of the high-temperature insulation layer and the number of layers of the nonwoven fabric with particles of silicon dioxide airgel distributed in it are determined by calculation in accordance with the requirements of SP 61.13330.2012 “Thermal insulation of equipment and pipelines” depending on the operating temperature of the coolant in the pipeline and specific operating conditions of the pipeline according to technical projects in such a way as to ensure the temperature at the interface of the layer of high-temperature thermal insulation / polyurethane foam not more than 13 0 ° C.

The calculated parameters of the thickness of the high-temperature insulation layer are given in Table 1.

Table 1.

The thickness of the layer of high-temperature thermal insulation (VTI) based on silicon dioxide airgel depending on the temperature of the coolant, (the number of layers of VTI is calculated based on a layer thickness of 5 mm)

Layers of a nonwoven fabric with particles of silicon dioxide airgel distributed in it are placed on the surface of the pipeline element by longitudinal or transverse wrapping or spiral winding so that each subsequent layer overlaps the joints of the webs in the previous layers (see Fig. 2).

The joints of individual webs are additionally fastened with heat-resistant metallized aluminum foil with adhesive tape and / or additionally covered with thin aluminum foil.

To increase the reliability of thermal insulation, nonwoven webs with particles of silicon dioxide airgel distributed in it can wrap the pipeline element "overlap".

In order to avoid the formation of “thermal bridges” during the thermal insulation of the butt joints of products during their installation and integration into heating and technological pipelines, a layer of high-temperature thermal insulation on the product is formed so that it protrudes beyond the waterproofing shell by at least 100 mm.

The formation of a layer of high-temperature thermal insulation by spiral winding can be carried out using a tensioner, which allows you to mechanize the process of forming thermal insulation (Fig. 12).

When forming a layer of high-temperature thermal insulation from two layers of the canvas, it is advisable to spiral winding with a step equal to 1/2 the width of the canvas, from three layers with a step equal to 1/3 the width of the canvas, etc.

After the formation of a layer of high-temperature thermal insulation on a steel pipeline element, centering supports are installed on its surface to ensure the alignment of the pipeline element and the waterproofing sheath.

The alignment of the pipeline element and the waterproofing sheath is an important and necessary condition for ensuring reliability during the installation and operation of the thermally insulated pipeline products in the heating network, heating main or process pipeline.

Centering supports can be made in the form of flexible clamps with tie locks and radially spaced racks or in the form of U-shaped elements fastened together by special locks, which allow assembling them into an adjustable ring diameter when assembling and installing individual U-shaped elements, which allows to ensure a tight fit of the centering supports to the layer of high-temperature thermal insulation of the pipeline element and the sealing of this layer under the centering supports.

The first centering support is installed at a distance of 500 mm from the end of the pipe element, and the subsequent ones with a pitch of not more than 800 mm from each other.

Before installing the centering supports, the high-temperature insulation layer is sealed at the installation sites of the centering supports by means of ring substrates in order to compress the high-temperature insulation layer under the centering supports by 10-20% of its initial thickness.

The ring substrates are cut out of a nonwoven fabric with distributed particles of silicon dioxide airgel and, on the outside, at the points of contact with the centering supports, tape is reinforced with adhesive metallized aluminum foil so that adhesive tape metallized with aluminum foil completely covers the outer surface of the ring substrate (Fig. 5).

When the next layer of thermal insulation is formed from a polyurethane foam over a layer of high-temperature thermal insulation during the structuring of polyurethane foam, an increased pressure is created in the internal volume of the structure, which leads to compaction of the high-temperature thermal insulation layer, which in turn can cause centering supports to shift under the weight of the pipeline element and cause structural misalignment.

Pre-compaction of the high-temperature insulation layer at the installation sites of the centering supports prevents the displacement of the centering supports and ensures their snug fit to the waterproofing sheath.

The authors experimentally established that an increase in the density of the applied high-temperature thermal insulation in the range of 10-20% does not affect the thermal conductivity and does not increase the temperature at the interface of the high-temperature thermal insulation layer / polyurethane foam thermal insulation layer.

After installing the centering supports, the surface of the high-temperature insulation layer should remain flat, without wrinkles or damage.

In the design of the proposed product in the formation of high-temperature insulation, a new, previously not used in the manufacture of such products, high-tech heat-insulating material based on silicon dioxide airgel in the form of a non-woven fabric with particles of silicon dioxide airgel distributed in it is used, the thermal insulation efficiency of which is several times higher than mineral cotton.

A comparison of the main thermophysical indicators - the thermal conductivity coefficients of a high-temperature thermal insulation layer based on silicon dioxide airgel and a high-temperature thermal insulation layer based on mineral wool is shown in Table 2:

Table 2.

Thermal conductivity coefficients of high-temperature thermal insulation based on silicon dioxide and mineral wool airgel

The use of thermal insulation with such low values of the coefficient of thermal conductivity makes it possible to significantly (almost 3 times) reduce the thickness of the first “barrier” layer of high-temperature thermal insulation in comparison with previously used mineral wool thermal insulation.

The value of the thermal conductivity coefficient of high-temperature thermal insulation is confirmed by the test results of independent laboratories.

To confirm the effectiveness of the proposed solutions and the possibility of achieving a technical result during their implementation, samples of thermally insulated structures were made and temperature measurements were made both on the surface of the steel pipe and at the interface between the layers of high-temperature insulation / layers of thermal insulation from polyurethane foam.

Temperature measurements were made using special sensors and continuously recorded for several days.

Data on the test results are shown in table 3.

Table 3

Comparative test results of high-temperature thermal insulation based on silicon dioxide airgel and high-temperature thermal insulation based on basalt mineral wool (for a steel pipe with a diameter of 325 mm and a coolant temperature of 250 ° C)

As follows from the table, the use of high-temperature insulation based on silicon dioxide airgel is much more effective compared to high-temperature thermal insulation based on mineral wool and can reduce the diameter of the product structure as a whole by more than two times and, accordingly, reduce the consumption of materials per linear meter of a thermally insulated product.

The studies conducted by the authors under production conditions showed that under the influence of the increased pressure arising during the pouring and structuring of polyurethane foam inside the structure, high-temperature thermal insulation based on mineral wool with a density of 40 to 80 kg / m ^{3 is} compressed by 30-50%, and in the case of cylinders mineral wool density of 90-120 kg / m ^3, the quantity of shrinkage is 20-30%, which leads to an increase in the density of the mineral wool with a corresponding increase in thermal conductivity that obusla Lebanon increased heat loss.

When the density of the thermal insulation material based on silicon dioxide airgel is not less than 120 kg / m ³ (preferably 160-180 kg / m ³ ), shrinkage occurs to a much lesser extent, not more than 10-15%. Moreover, it was found that increasing the density of the heat-insulating material based on silicon dioxide airgel practically does not affect its thermal conductivity coefficient.

In addition, it was experimentally established that polyurethane foam has high adhesion to the surface of high-temperature thermal insulation based on silicon dioxide airgel, while when using high-temperature thermal insulation from mineral wool, it is necessary to use mats or cylinders coated with aluminum foil to adhere the polyurethane foam to its surface.

Moreover, during the long-term operation of such structures, the adhesive layer gradually burns out, with the help of which aluminum foil is attached to the surface of the mineral wool cylinder, which in turn leads to a violation of the integrity of the structure.

High adhesion of polyurethane foam to the surface of a layer of high-temperature thermal insulation based on silicon dioxide airgel allows to increase the rigidity of the structure and eliminates the possibility of shear and deformation of high-temperature thermal insulation layers inside the product.

After installing the centering supports inside the structure of products with a polyethylene waterproofing sheath, used for underground laying of heating networks, heating mains and process pipelines, conductors of the operational remote control system (UEC) can be installed, which allows controlling the change in humidity of the heat-insulating layer of polyurethane foam caused by moisture penetration through waterproofing shell, or due to leakage of the coolant from the steel pipeline due to corrosion defects of welded joints.

After installing the conductors of the on-line remote control system, a thermally-insulated pipeline product is assembled with a layer of high-temperature thermal insulation and a waterproofing membrane applied to the pipeline element with the formation of a pipe-in-pipe construction.

The waterproofing sheath of low-pressure polyethylene is produced by extrusion on specialized lines commonly used for this.

The diameter of the waterproofing polyethylene sheath in the range from 110 to 1200 mm is selected from the standard series GOST 30732-2006 "Steel pipes and fittings with thermal insulation from polyurethane foam with a protective sheath" in accordance with the calculation of the thickness of the high-temperature thermal insulation layer.

During the extrusion process, the inner surface of the polyethylene waterproofing sheath is treated with a corona discharge to increase the adhesion of polyurethane foam to the polyethylene sheath.

In products used for the overhead installation of heating networks, heating mains and technological pipelines, the waterproofing sheath is made of galvanized sheet steel with a sealed seam on a conventional spiral-wound machine. The inner surface of the spiral steel shell is treated with a phosphating modifier, including an anti-corrosion film former to increase the adhesion of polyurethane foam to the surface of the steel waterproofing shell.

The diameter of the waterproofing steel sheath in the range from 110 to 1600 mm is selected from the standard series GOST 30732-2006 "Steel pipes and fittings with thermal insulation from polyurethane foam with a protective sheath" in accordance with the calculation of the thickness of the high-temperature thermal insulation layer.

During assembly, the waterproofing sheath on the product is formed as follows:

A pipe element with a layer of high-temperature insulation formed on it and installed centering supports is fed to the assembly table to the place of assembly of the product, which also serves as a waterproofing shell.

The conveyor is launched and the pipeline element is pushed into the waterproofing shell.

Pouring the pipe-in-pipe design with rigid polyurethane foam with a density of not less than 60 kg / m ³ and a thermal conductivity coefficient of not more than 0.033 W / (m * ° C) is carried out on conventional injection and filling high-pressure plants designed to supply liquid polyurethane components (polyol and isocyanate) in the annular space between the piping element waterproofing shell.

In the event that the temperature of the assembled structure is below 20 ° C, it is heated to a temperature of 30-40 ° C.

The assembled structure is hoisted to the heating table.

Hot air with a temperature of 60-70 ° C from the blower is fed through air ducts into the space between the surface of the pipeline element with a layer of high-temperature thermal insulation and a waterproofing shell.

After heating, casting flanges are installed on the assembled structure, which tightly close the end surfaces of the product.

The casting table is raised to the required angle of inclination, which ensures uniform distribution of the components of the polyurethane foam along the length of the pipeline element.

Set the pouring time on the timers of the mixing head and make the injection (injection) of the components of the polyurethane foam.

After the injection time has elapsed, the mixing head closes and is automatically cleaned.

Polyurethane foam is formed by mixing two components (polyol and isocyanate), which are liquid mixtures.

As a result of mixing these two components, a reactive mixture is formed, which foams under the influence of the generated heat. At the end of the reaction phase, the foam hardens.

The beginning of the polymerization reaction of polyurethane foam is controlled by the temperature of the outer surface of the waterproofing shell and the air outlet through the holes for air removal.

The duration of the polymerization reaction of polyurethane foam is 3-5 minutes, but the product, depending on the diameter, is kept stationary for at least 15-30 minutes.

The technological process of thermal insulation of shaped products is similar to the process of thermal insulation of pipes.

The design of shaped products (bends, transitions, tees, etc.) is determined by design decisions, in FIG. 5-10 show possible examples of shaped products with the proposed combined thermal waterproofing.

Thermally insulated shaped products are made as follows:

They cut steel pipes, weld and assemble the steel structure of the shaped product.

A layer of heat-resistant anti-corrosion coating is applied to the surface of the pipeline element of the shaped article.

First, a layer of high-temperature thermal insulation is cut, taking into account the design of the pipeline element of the shaped product.

Cutting is done according to patterns made in accordance with the developed drawings in such a way as to minimize the loss of thermal insulation material.

A layer of high-temperature thermal insulation is formed on the surface of the pipeline element of the shaped product and in the joints, they are fixed with adhesive tape with heat-resistant metallized aluminum foil.

High efficiency of using high-temperature thermal insulation based on airgel for the manufacture of shaped products has been revealed.

A thin, flexible, elastic non-woven fabric with distributed particles of silicon dioxide airgel is easy to cut, mechanically fastened, fits snugly to the surface of pipeline elements in the places of bends, suitable for thermal insulation of surfaces of almost any shape and configuration.

When forming a layer of high-temperature thermal insulation, a non-woven fabric with distributed particles of silicon dioxide airgel is preferably applied in an amount of at least two layers so that each subsequent layer overlaps the junction of the previous layer.

Set the centering supports, which ensure the alignment of the design of the pipeline element of the shaped product and waterproofing shell.

Before installing the centering supports of the pipeline element of the shaped product, the high-temperature thermal insulation is sealed in the places of their installation by means of ring substrates in order to provide compression of the high-temperature thermal insulation layer by at least 10-15% of its initial thickness.

After installing the centering supports, conductors of the operational remote control system (UEC) can be installed in the product, allowing to control the increased humidity of the heat-insulating layer caused either by the penetration of moisture through the protective sheath, or due to leakage of the coolant from the steel pipe due to corrosion or defects in welded joints.

Then, the assembly of the structure is carried out with a layer of high-temperature thermal insulation and a waterproofing shell.

Casting flanges are installed on the assembled product structure, which tightly close the end surfaces of the product.

Pipe structures in the pipe-to-pipe type are filled with rigid polyurethane foam with a density of at least 60 kg / m ³ and a thermal conductivity coefficient of not more than 0.033 W / (m * ° C) at injection and filling high-pressure plants designed to supply liquid polyurethane components (polyol and isocyanate) into the annulus of the pipe element with a layer of high-temperature thermal insulation and a waterproofing sheath.

Heat-insulated pipes and fittings can be produced under industrial conditions on conventional production lines with a slight modernization.

Shown in FIG. 11, the design of the butt joint of the proposed thermally insulated products provides reliable thermal and hydro insulation of the joints of the elements of the pipeline in accordance with the requirements of GOST 30732-2006 and SP 41-105-2002.

Thermo-waterproofing of butt joints on the route is carried out after completion of pipeline installation, testing, including hydraulic tests.

Waterproofing of butt joints can be performed by heat-shrinkable couplings.

Before welding steel pipes, a heat-shrinkable sleeve is installed on the polyethylene waterproofing sheath of the joined pipe or fittings.

Pipes are welded, their surface is cleaned from traces of corrosion.

A heat-resistant anti-corrosion coating is applied to the prepared surface, for example, enamel KO 8104 grade B (silver color).

After the anticorrosion coating has completely dried, a barrier layer of high-temperature thermal insulation is installed on the steel pipe. At least two layers of high-temperature thermal insulation are installed so that the top layer overlaps the junction of the previous layers. The heat-insulating layer is fixed with heat-resistant metallized aluminum foil with adhesive tape.

By heating the surface with a flame of gas burners, heat-shrink the polyethylene sleeve.

Filling of butt joints is carried out using a two-component polyurethane foam system. The polyol and isocyanate are mixed with a high-speed mixer in a special container and a homogeneous mixture is poured through the prepared hole in the heat-shrinkable sleeve. The hole is closed with drainage plugs, and after curing the heat-insulating layer of polyurethane foam, it is brewed.

The manufacture of the proposed products and the implementation of the proposed method for the manufacture of heat-insulated products for underground and above-ground heating pipelines and process pipelines can be carried out using well-known standard equipment, materials and technologies.

Thus, a detailed disclosure of the industrial implementation of the invention shows the necessity and sufficiency of all the essential features of the claims, shows a causal relationship of the essential features and the technical result and ensures the confident achievement of the technical result - simplification of manufacturing technology, reducing production and installation costs and improving operational properties and reliability of use heat-insulated piping products designed for subzone me and the elevated laying of heating networks, heating mains and technological pipelines operated at a coolant temperature

Given the novelty of the set of essential features, the technical solution of the problem, the inventive step and the materiality of all general and particular features of the invention, proven in the section "Prior Art" and "Summary of the Invention", proved in the section "Implementation and industrial implementation of the invention", technical feasibility and industrial the applicability of the invention, the solution of the problem and the confident achievement of the required technical result in the implementation and use of the invention, the claimed Rupp inventions satisfies all the requirements for eligibility requirements for inventions.

The analysis also shows that all the general and particular features of the invention are essential, since each of them is necessary, and all together they are not only sufficient to achieve the purpose of the invention, but also make it possible to realize the invention in an industrial way.

In addition, the analysis of the set of essential features of the invention and achieved by using a single technical result shows the presence of a single inventive concept, close and inextricable connection between the inventions of the group, namely the manufacture of the proposed product by the proposed method, which allows you to combine the two inventions in one application.

Claims (42)

1. A thermo-insulated pipeline product for high-temperature heating networks, heating mains and process pipelines, comprising a pipeline element and heat insulation and waterproofing sequentially arranged above it, characterized in that the thermal insulation comprises a layer of high-temperature thermal insulation from a material based on silicon dioxide airgel and located above it a layer of thermal insulation made of polyurethane foam with ensuring temperature at the interface a layer of high-temperature thermal insulation - a thermal insulation layer of polyurethane foam no more than 130 ° C. 2. A thermally-insulated pipeline product according to claim 1, characterized in that the thermal insulation layer of polyurethane foam contains rigid polyurethane foam with a density of at least 60 kg / m ³ and a thermal conductivity coefficient at 50 ° C of not more than 0.033 W / (m ° C). 3. A thermally-insulated pipeline product according to claim 1, characterized in that the high-temperature thermal insulation layer contains silicon dioxide airgel and has a thermal conductivity of not more than 0.022 W / (m ° C) at 25 ° C and not more than 0.035 W / (m ° C) at 260 ° C. 4. A thermally-insulated pipeline product according to claim 1, characterized in that the high-temperature insulation layer is made of a non-woven fabric with particles of silicon dioxide airgel distributed therein. 5. The thermally-insulated pipeline product according to claim 4, characterized in that the high-temperature thermal insulation layer is made of several layers of non-woven fabric with particles of silicon dioxide airgel distributed therein. 6. A thermally-insulated pipeline product according to claim 4, characterized in that the high-temperature thermal insulation layer is made of several layers of non-woven fabric with silicon dioxide airgel particles distributed therein by spiral winding. 7. A thermo-insulated pipeline product according to claim 4, characterized in that the high-temperature thermal insulation layer is made of several layers of non-woven fabric with silicon dioxide airgel particles distributed therein, located one above the other with mutual overlapping of joints and with an intermediate coating of layers and joints of the fabric with heat-reflecting material for example with thin aluminum foil or metallized aluminum foil with adhesive tape. 8. A thermally insulated pipeline product according to claim 1, characterized in that centering supports are installed on the surface of the high-temperature thermal insulation layer with the possibility of alignment of the pipeline element with a layer of high-temperature thermal insulation and waterproofing in the form of a waterproofing shell. 9. A thermo-insulated pipeline product according to claim 8, characterized in that annular substrates are located on the surface of the high-temperature insulation layer under the centering supports. 10. A thermally-insulated pipeline product according to claim 9, characterized in that the ring substrates located on the surface of the high-temperature insulation layer under the centering supports are capable of densifying 10-20% of the high-temperature insulation layer and prevent the centering supports from shifting, preserving the alignment and tight fit of the centering supports to the waterproofing sheath. 11. Heat-insulated pipeline product according to claim 9, characterized in that the ring substrates located on the surface of the high-temperature insulation layer under the centering supports are made of a non-woven fabric with silicon dioxide aerogel particles distributed therein 12. A thermally-insulated pipeline product according to claim 9, characterized in that the ring substrates on the outside are reinforced with heat-reflecting material, for example, thin aluminum foil or metallized aluminum foil with adhesive tape, located on the surface of the high-temperature insulation layer under the centering supports. 13. Thermally insulated pipeline product according to claim 1, characterized in that it is made in the form of thermally insulated pipes. 14. A thermally-insulated pipeline product according to claim 1, characterized in that it is made in the form of a thermally-insulated shaped pipe element in the form of a branch, tee, transition between pipelines of various diameters or Z-shaped, L-shaped, Y-shaped, L-shaped, U -shaped heat-insulated shaped element. 15. The thermally-insulated pipeline product according to claim 1, characterized in that it comprises a pipeline element with a diameter of 25 to 1420 mm. 16. Heat-insulated pipeline product according to p. 15, characterized in that it contains a steel pipe element with an outer surface previously cleaned from rust and treated with a high-temperature resistant anticorrosion coating, preferably containing a suspension of aluminum powder and target additives in a modified organosilicon film-forming compound, for example, enamel heat-resistant KO 8104 silver-gray grade B TU 2312-421-05763441-2003. 17. Heat-insulated pipeline product according to claim 1, characterized in that it is designed for laying underground heating networks, heating mains and process pipelines and is made with waterproofing in the form of a waterproofing shell made of low-pressure polyethylene 18. A thermo-insulated pipeline product according to claim 17, characterized in that it is made with waterproofing in the form of a waterproofing shell of low pressure polyethylene with a corona treated inner surface to increase the adhesion of polyurethane foam to polyethylene. 19. A thermally-insulated pipeline product according to claim 1, characterized in that it is designed for laying elevated heating pipelines and process pipelines and is made with waterproofing in the form of a waterproofing shell made of spiral galvanized sheet steel. 20. A thermally-insulated pipeline product according to claim 19, characterized in that it is made with waterproofing in the form of a waterproofing sheath from a spiral-wound galvanized sheet steel with a phosphating modifier and an anti-corrosion film former treated with an inner surface to increase the adhesion of polyurethane foam to galvanized steel. 21. A thermally-insulated pipeline product according to claim 1, characterized in that the high-temperature insulation layer based on silicon dioxide airgel along the end parts of the product is made with respect to the upper layer of thermal insulation made of polyurethane foam and waterproofing protruding by at least 100 mm with the possibility of being embedded in the heating main or technological pipeline and subsequent thermal insulation of butt joints with connecting elements containing a layer of high-temperature thermal insulation based on aerog eating silica and the layer of thermal insulation made of polyurethane foam located above it. 22. A method of manufacturing a thermally insulated pipeline product for high-temperature heating networks, heating mains and process pipelines, comprising manufacturing a pipeline element with heat insulation and waterproofing sequentially disposed thereon, characterized in that the insulation is made in the form of a layer of high-temperature thermal insulation from a material based on silica airgel and the foam insulation layer above it polyurethane with ensuring temperature at the interface layer of high-temperature thermal insulation - thermal insulation layer of polyurethane foam not more than 130 ° C. 23. A method of manufacturing a thermally-insulated pipeline product according to claim 22, characterized in that a high-temperature thermal insulation layer is made with a thermal conductivity of not more than 0.022 W / (m ° C) at 25 ° C and not more than 0.035 W / (m ° C) at 260 ° C. 24. A method of manufacturing a thermally insulated pipeline product according to claim 22, characterized in that the thermal insulation layer of polyurethane foam is made of rigid polyurethane foam with a density of at least 60 kg / m ³ and a thermal conductivity at 50 ° C of not more than 0.033 W / (m ° C). 25. A method of manufacturing a thermally insulated pipeline product according to claim 22, characterized in that the high-temperature thermal insulation layer is made of a non-woven fabric with silicon dioxide airgel particles distributed therein. 26. A method of manufacturing a thermo-insulated pipeline product according to claim 22, characterized in that the high-temperature thermal insulation layer is made of several layers of non-woven fabric with particles of silicon dioxide airgel distributed therein. 27. A method of manufacturing a thermally insulated pipeline product according to claim 26, characterized in that the high-temperature thermal insulation layer is made of several layers of non-woven fabric with silicon dioxide airgel particles distributed therein by spiral winding. 28. A method of manufacturing a thermally insulated pipeline product according to 25, characterized in that the high-temperature thermal insulation layer is made of several layers of non-woven fabric with silicon dioxide airgel particles distributed thereon, located one above the other with mutual overlap of the joints of the fabric. 29. A method of manufacturing a thermally insulated pipeline product according to claim 25, characterized in that the high-temperature thermal insulation layer is made of several layers of non-woven fabric with an intermediate coating of layers and joints of the fabric with heat-reflecting material, for example, thin aluminum foil or metallized aluminum foil with adhesive tape. 30. A method of manufacturing a thermally insulated pipeline product according to claim 22, characterized in that centering supports are installed on the surface of the high-temperature insulation layer with the possibility of alignment of the pipeline element with the layer of high-temperature insulation and waterproofing in the form of a waterproofing shell. 31. A method of manufacturing a thermally insulated pipeline product according to claim 22, characterized in that centering supports are installed on the surface of the high-temperature insulation layer with ring substrates placed under them with the possibility of sealing by 10-20% of the high-temperature insulation layer and preventing the alignment of the centering supports from shifting, maintaining alignment and tight fit of the centering supports to the waterproofing in the form of a waterproofing shell. 32. A method of manufacturing a thermally insulated pipeline product according to claim 31, characterized in that the annular substrates placed on the surface of the high-temperature insulation layer under the centering supports are made of a non-woven fabric with silicon dioxide aerogel particles distributed therein. 33. A method of manufacturing a thermally insulated pipeline product according to claim 31, characterized in that the annular substrates placed on the surface of the high-temperature thermal insulation layer under the centering supports are reinforced with heat-reflecting material, for example, thin aluminum foil or metallized aluminum foil with adhesive tape. 34. A method of manufacturing a thermally insulated pipeline product according to claim 22, characterized in that the article is made in the form of a thermally insulated pipe. 35. A method of manufacturing a thermally insulated pipeline product according to claim 22, characterized in that the article is manufactured in the form of a thermally insulated shaped pipe element in the form of a branch, tee, transition between pipelines of various diameters or Z-shaped, L-shaped, Y-shaped, L- shaped, U-shaped thermally insulated shaped element. 36. A method of manufacturing a thermally insulated pipeline product according to claim 22, characterized in that a steel pipe element with a diameter of 25 to 1420 mm is used. 37. A method of manufacturing a thermally insulated pipe product according to claim 36, characterized in that the outer surface of the steel pipe element is pre-cleaned of rust and treated with a high temperature resistant anti-corrosion coating, preferably containing a suspension of aluminum powder and target additives in a modified organosilicon film-forming compound, for example enamel of heat-resistant KO 8104 silver-gray grade B TU 2312-421-05763441-2003. 38. A method of manufacturing a thermally insulated pipeline product according to claim 22, characterized in that the product is made for laying underground heating pipelines and process pipelines with waterproofing in the form of a waterproofing shell made of low pressure polyethylene. 39. A method of manufacturing a thermally insulated pipeline product according to claim 22, characterized in that the product is made with waterproofing in the form of a waterproofing shell of low pressure polyethylene with a corona treated inner surface to increase the adhesion of polyurethane foam to polyethylene. 40. A method of manufacturing a thermally insulated pipeline product according to p. 22, characterized in that the product is made intended for laying elevated heating pipelines and process pipelines with waterproofing in the form of a waterproofing shell made of spiral galvanized sheet steel. 41. A method of manufacturing a thermally insulated pipeline product according to claim 22, characterized in that the product is manufactured for laying elevated heating pipelines and process pipelines with waterproofing in the form of a waterproofing shell made of spiral galvanized sheet steel with a phosphating modifier and anticorrosive film-forming agent coated with an inner surface for increasing adhesion foam to galvanized steel. 42. A method of manufacturing a thermo-insulated pipeline product according to claim 22, characterized in that the high-temperature insulation layer based on silicon dioxide airgel along the end parts of the product is performed with respect to the upstream layer of thermal insulation from polyurethane foam and waterproofing protruding by at least 100 mm with the possibility of being embedded in heating main or technological pipeline and subsequent thermal insulation of butt joints with connecting elements containing a layer of high-temperature heat silica airgel-based insulation and a polyurethane foam thermal insulation layer located above it.

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