RU2762816C1 - Exhaust apparatus of a gas pumping unit - Google Patents

Abstract

FIELD: gas turbine engines.

SUBSTANCE: invention relates to structures of aviation gas turbine engines, in particular, to structures of assemblies for removal of hot gases. An exhaust apparatus of a gas pumping unit, containing elements consisting, in turn, of four walls, or in the form of a circular pipe. All walls consist of a non-bearing hot part and a bearing cold part interconnected by assemblies excluding transfer of axial and radial forces, occurring on heat expansion of the non-bearing hot shell, to the bearing cold shell and reducing heat transfer between interconnected shells.

EFFECT: provides a possibility of excluding deformation and destruction of sheets of the outer lining of exhaust shafts during operation due to the compensation for the heat expansion of metal in the vertical and horizontal planes during operation of the GPU.

8 cl, 12 dwg, 2 tbl

Description

The invention relates to the design of gas pumping units using gas turbine engines (aircraft, marine, stationary) as a drive, in particular, to the design of units designed to remove hot gases into the surrounding space.

The exhaust device of the gas pumping unit contains elements, which, in turn, consist of four walls, or in the form of a round pipe. All walls consist of a load-bearing cold part and a non-load-bearing hot part, connected to each other. The load-bearing cold part and the non-load-bearing hot part are interconnected by rigid joints at one point and expansion joints in several places of each sheathing sheet of the hot part of the non-load-bearing frame, thereby eliminating temperature deformations.

Various types of exhaust devices are used to remove into the environment the hot products of combustion of gas turbine engines in gas-compressor units - GPUs.

Known exhaust device of a turbomachine according to the RF patent for invention No. 2504665, IPC F01D 25/30, publ. 20.01.2014

This exhaust device of the turbomachine contains a housing with an inlet located around the axis of rotation of the turbine, a diffuser, an outlet located in the outer wall of the housing, and an additional baffle. The diffuser includes axial and radial parts, formed respectively by the inner and outer duct walls located inside the housing around the axis of rotation of the turbine. An additional partition is made inside the device body in a plane perpendicular to the turbine rotation axis, with a perimeter equal to the perimeter of the device body walls parallel to it. In the additional partition, a hole is made coaxially to the axis of rotation of the turbine, the diameter of which is equal to the maximum diameter of the outer path wall of the radial part of the diffuser.

Disadvantages: loss of strength and deformation of the walls due to exposure to high temperatures.

Known snail for exhaust gases of a gas turbine engine according to the RF patent for useful model No. 116910, IPC F02C 1/00, publ. 10.06.2012

This scroll for exhaust gases of a gas turbine engine contains a housing with front, rear and side walls, and an axial radial diffuser located between the front and rear walls of the housing, having a cavity for accommodating the outlet unit of a gas turbine engine, and also containing inner and outer shells with flanges, - in it, each of the flanges of the inner and outer shells of the diffuser is made composite in the form of a ring and an annular shell, connected by welding, while the flange ring of the inner shell of the diffuser is made of a hollow metal pipe, and the ring of the flange of the outer shell of the diffuser is made of a metal bar of a round transverse sections, the annular shells of the flanges of the inner and outer shells of the diffuser are made of sheet metal material, each of which is welded to the corresponding rings of the flanges of the shells of the diffuser, the outer shell is fastened to the inner shell of the diffuser by arc welding, made made from a metal bar with a cross-sectional cross-section.

Disadvantage: no measures are provided to reduce the temperature of the outer wall of the exhaust device.

Known diffuser of the exhaust tract of the gas pumping unit for the RF patent for invention No. 2 313030 C2, IPC F16L 59/00, publ. 12/20/2007, prototype

In the diffuser of the exhaust tract of a gas pumping unit with a gas turbine installation, containing a shell with flanges, a casing covering the shell and consisting of side panels, a roof and a sump, and sound insulation placed between the shell and the casing and fixed to the shell by means of fasteners, for example, pins installed on the shell and passed through the sound and heat insulation, a gap is formed between the sound and heat insulation and the casing, while the ends of the fasteners, such as pins, do not have contact with the wall of the casing and are interconnected by flexible elements.

The disadvantages of the prototype and most of the operated exhaust mines as part of gas pumping units on gas pipelines include:

- high temperature on the outer cladding of the walls of the exhaust shafts, in connection with which it becomes impossible to inspect and maintain the exhaust shafts in the area of possible contact of the service personnel;

- deformation and destruction of outer skin sheets (formation of longitudinal and transverse cracks) of exhaust shafts during operation due to uneven heating of the wall frames of the exhaust shaft elements, which lead to inconsistent deformations of rigidly connected parts (inner and outer wall skin), as a result of which cracks appear in welded seams and sheathing sheets;

- destruction of the paint and varnish coating and the formation of foci of corrosion of the outer casing of the exhaust shaft due to a sharp temperature drop during the operation of the gas pumping unit at the border of zones with low temperatures and local zones with high temperatures;

- low cyclic strength of the exhaust shaft frame elements due to the absence of temperature decoupling in them and the presence of nodes with rigidly connected parts, which leads to the formation of significant internal stresses in the welded joints of the bearing elements;

- inconsistency with the permissible sound pressure level in octave frequency bands and sound levels in working areas due to the use of thermal insulation that is not resistant to vibration during operation, as well as partial destruction of the inner lining sheets and, as a result, the blowing of thermal insulation from the internal cavities of the exhaust shaft elements.

- overflow of exhaust gases from a gas turbine engine (GTE) from the inner cavity of the mine to the outside due to the occurrence of internal stresses during the operation of the gas pumping unit, which contribute to the deviation from the flatness of the flange joints.

The task of creating the invention: to exclude deformation and destruction of the sheets of the outer skin of the exhaust shafts during operation due to the compensation of the thermal expansion of the metal in the vertical and horizontal planes during the operation of the GPU.

Achieved technical results:

Minimization of temperature deformations and lowering the temperature of the outer shell of the exhaust device walls to values that allow safe inspection and maintenance of the exhaust device by the GPU personnel.

The solution to this problem has been achieved in the exhaust device of a gas pumping unit containing elements that, in turn, consist of four walls or in the form of a round pipe, characterized in that all walls consist of a non-load-bearing hot part and a load-bearing cold part, interconnected by nodes, excluding transfer of axial and radial forces arising from thermal expansion of a non-load-bearing hot shell onto a load-bearing cold shell and reducing heat transfer between shells connected to each other.

The load-bearing cold part of the section may consist of a load-bearing frame made of bent shaped rolled steel and sheets of inner lining with a device on them for holding devices for lining the hot part, and the non-load-bearing hot part of the section consists of sheets of inner lining of relatively thinner thickness, parts and assemblies that allow holding inner sheathing sheets in the plane of the walls.

Units that exclude the transfer of axial and radial forces arising from the thermal expansion of a non-load-bearing hot shell to a load-bearing cold shell can be made in the form of a compensator that compensates only for vertical movements, compensates for only horizontal displacements and compensates for both horizontal and vertical displacements.

The thickness of the outer sheathing sheet can be:

δ ₁ = (2 ... 4) δ ₂ ,

where: δ ₁ - thickness of the outer skin sheet,

δ ₂ - thickness of the inner skin sheet.

The thickness of the inner lining sheet can be:

δ ₂ = 2 ... 4 mm.

The thickness of the second layer of thermal insulation can be:

δ ₄ = (5 ... 11) δ ₃ ,

where: δ ₃ - thickness of the first layer of thermal insulation,

δ ₄ - thickness of the second layer of thermal insulation.

The thickness of the second layer of thermal insulation can be:

δ ₄ = 125 ... 275 mm.

One of the elements can be equipped with a muffler, which includes rectangular muffler plates.

The essence of the invention is illustrated in the drawings (Fig. 1-12), where:

- in Fig. 1 shows a diagram of a gas pumping unit - GPA,

- in Fig. 2 shows a diagram of the exhaust device,

- in Fig. 3 shows a section A-A, the first option,

- in Fig. 4 shows a section A-A, the second option,

- in Fig. 5 shows the wall,

- in Fig. 6 shows a structural diagram of a non-load-bearing hot and load-bearing cold wall, section С-С,

- in Fig. 7 shows the hairpin assembly,

- in Fig. 8 shows a diagram of the attachment point of the inner hot shell to the frame elements and to each other, section D-D,

- in Fig. 9 shows a structural diagram of a load-bearing cold wall.

- in Fig. 10 shows a structural diagram of linear expansion joints on the inner sheathing sheets (typical),

- in Fig. 11 shows the enamel coating of a sheet of outer skin,

- in Fig. 12 shows the noise suppression scheme.

The list of features accepted in the description:

gas pumping unit 1,

air intake device 2,

exhaust device 3.

a separate element of the exhaust device 4,

wall 5,

flange 6,

studded connection 7.

load-bearing cold part 8,

non-load-bearing hot part 9,

power frame 10,

outer sheathing sheet 11,

inner lining sheet 12,

hold-down washer 13,

support washer 14.

pressure channel 15.

the first layer of thermal insulation 16,

the second layer of thermal insulation 17,

exhaust gas path 18.

comb 19,

hairpin 20,

rack 21,

cross member 22,

welding seam 23,

nut 24,

contact welding 25,

an expansion joint that only compensates for vertical movements 26,

an expansion joint that only compensates for horizontal movements 27,

an expansion joint that compensates for both horizontal and vertical movements 28,

enamel coating 29,

noise dampening device 30,

sound attenuation plates 31.

D is the outer diameter of the device,

d is the inner diameter of the device.

B - external width of the device,

в - internal width of the device.

δ ₁ - thickness of the outer skin sheet,

δ ₂ - thickness of the inner lining sheet,

δ ₃ - thickness of the first layer of thermal insulation,

δ ₄ - thickness of the second layer of thermal insulation.

Gas pumping unit 1 (Fig. 1) is equipped with an air intake device 2 and an exhaust device 3. The exhaust device 3 is made of separate elements 4, which can consist of either four walls 5. forming a rectangular section, or in the form of a round pipe (Figs. 3 and 4 ). Elements 4 of the exhaust device are interconnected through flanges 6, connected by stud (bolted) connections 7.

All walls 5 of rectangular and circular cross-section consist of a load-bearing cold part 8 and a non-load-bearing hot part 9 (Figs. 3 and 4).

The load-bearing cold part of the wall 8 consists of a load-bearing frame 10 made of bent shaped steel and sheets of the outer skin 11 having a thickness of δ ₁ , connected by welding seams.

The non-bearing hot part 9 (Figs. 3 and 4) of the wall consists of sheets of the inner lining 12 of a relatively thinner thickness δ ₂ , pressure washers 13, support washers 14 and pressure channels 15 made of bent shaped steel.

Recommended thickness of internal cladding sheets 12 (Fig. 3 and 4):

δ ₂ = 2-4 mm.

Recommended thickness for external cladding sheets 11:

δ ₁ = 4-8 mm.

The thickness of the first thermal insulation layer of thermal insulation can be: δ ₃ = (2 ... 4) δ ₄ ,

where: δ ₃ - thickness of the first layer of thermal insulation,

δ ₄ - thickness of the second layer of thermal insulation.

The thickness of the first thermal insulation layer of thermal insulation can be: δ ₃ = 125 ... 275 mm.

The proof of the optimal ratio of the thicknesses of the sheets of the inner and outer skin 12 and 11 is given in table. one.

The proof of the optimal ratio of the thicknesses of the second and first layers of insulation 17 and 16 is given in table. 2.

Conclusion from table. 2.

The optimal ratio of the thicknesses of the thermal insulation layers (second and first):

δ ₄ / δ ₃ = 5 ... 11.

Optimum absolute thicknesses of thermal insulation layers:

δ ₃ = 25 mm; δ ₄ = 125 ... 275 mm.

Such a thickness of the heat-insulating layers δ ₃ and δ ₄ provides a temperature reduction by 450-550 ° C.

In a specific example, at an exhaust gas temperature of 500-620 ° C, the temperature of the non-bearing cold part is 40-65 ° C. At the same time, for the prototype, it was 150-200 ° C. Basalt mats can be used as a material for thermal insulation (first layer), and ceramic fiber mats can be used for thermal insulation (second layer).

Angles, channel bars, or any steel produced by the industry can be used as bent shaped rolled products.

Between the cold bearing 8 and the hot non-bearing 9 parts are two layers of thermal insulation: the first 16 and the second 17 (Fig. 3 and 4).

The thickness of the first layer of thermal insulation 16 - δ ₃ , and the second layer of thermal insulation 17 - δ ₄ (Fig. 3 and 4).

An exhaust gas path 18 is formed inside the device.

The cold and hot parts of the walls 8 and 9 can be connected by means of combs 19 and pins 20 (Figs. 6 and 7) at points with a rigid connection (one point per inner lining sheet) that do not allow the inner lining sheets to move and thereby fix them in the design position, for example, with a round hole in the sheathing sheet by compression with pressure washers through the nuts locked by welding (Fig. 10).

At all other points, the connection of the hot and cold parts must be made using combs 19 with welded pins 20 and struts 21 with crossbars 22 (Figs. 6 and 7), that is, in such a way as to compensate for the calculated thermal expansion of the inner lining sheets and additional loads caused by vibration during the operation of the GPU and the impact of the flow of exhaust gases.

Studs 20 are attached with a weld 23 on one side and a nut 24 on the other.

Nut 24 is fixed by contact welding 25.

FIG. 8 and 9 show the installation of the pressure channel 15.

The pressure channel 15, which is part of the frame 10, is installed between the casing sheets, closing the thermal gap along the vertical edges along the flow direction (Fig. 9). Studs 20 are fixed with a weld 23 and nuts 24, the nuts 24 themselves are fixed by contact welding 25,

In this case, three types of compensators are used on the sheathing sheets, which make it possible to compensate for thermal expansion (Fig. 10).

26 - compensator compensating only vertical movements,

27 - compensator compensating only horizontal movements,

28 - compensator that compensates for both horizontal and vertical movements.

FIG. 10 shows a compensator that only compensates for vertical movements 26.

This expansion joint 26 can be made in the form of a comb with a welded vertical pin on which a support washer is installed, which, in turn, serves as a stop in the plane for the inner lining sheet from the side of the thermal insulation. On the sheathing sheet, which is installed on the expansion joint, a horizontal groove is made, which limits the movement of the sheet, interacting with the vertical expansion joint pin vertically, but allowing the sheet to move horizontally. The inner lining sheet from the side of the flow path is limited in the plane by compression with a pressure washer through a nut locked by welding.

FIG. 10 shows a compensator that only compensates for horizontal movements 27.

This expansion joint 27 can be made in the form of a comb with a welded vertical pin on which a support washer is installed, which, in turn, serves as a limiter in the plane for the inner lining sheet from the side of the thermal insulation. On the sheathing sheet, which is installed on the expansion joint, a vertical groove is made, which limits the movement of the sheet, interacting with the vertical expansion joint pin horizontally, but allowing the sheet to move vertically. The inner lining sheet from the side of the flow path is limited in the plane by compression with a pressure washer through a nut locked by welding.

FIG. 10 shows a compensator that compensates for vertical and horizontal movements 28.

This expansion joint 28 can be made in the form of a comb with a welded vertical pin, on which a support washer is installed, which, in turn, serves as a stop in the plane for the inner lining sheet from the side of the thermal insulation. A round groove is made on the sheathing sheet, which is installed on the expansion joint, which does not restrict the movement of the sheet either horizontally or vertically, keeping the sheet in the plane allowing the sheet to move in all directions. The inner lining sheet from the side of the flow path is limited in the plane by compression with a pressure washer through a nut locked by welding.

The correct values of the thermal gap parameters must be selected between the pins and grooves in the sheathing sheets. Their values must exceed the values of the thermal elongation, plus the manufacturing error.

FIG. 11 shows a sheet of outer skin 11 with a coating layer 29 applied to it.

FIG. 12 shows a diagram of the installation of a sound-dampening device 30, in one of the sections 5. The sound-dampening device 30 contains sound-dampening plates 31 installed along the exhaust gas path 18.

DEVICE OPERATION

During operation of the GPU 1 (Fig. 1), air is sucked in by the air intake device 2 and is used to burn fuel supplied to the gas turbine engine as part of the GPU 1 (the gas turbine engine is not shown in Figs. 1-12).

Combustion products (GTE exhaust gases), having a temperature of 500 ° C-620 ° C, are emitted into the atmosphere through exhaust device 3, while the hot inner shells of the assemblies are exposed to a significant thermal effect, which reduces the strength characteristics of the materials used.

In order to eliminate the negative impact of the heat flow on the bearing elements of the exhaust device elements, all power elements are located in the "cold" zone.

The absence of temperature deformations in the junctions of cold and hot shells, as well as hot shells with each other, is ensured by the correct choice of the values of the thermal gap parameters. Their values must exceed the values of the thermal elongation, plus the manufacturing error.

The non-bearing cold part 8 has a coating 29 (Fig. 11) to exclude the effects of atmospheric precipitation in the form of heat-resistant enamel.

The use of noise suppression plates 31 (Fig. 12) in the noise-attenuating device 30 reduces the noise level.

The use of the proposed design scheme for the thermal decoupling of the walls of the exhaust shaft elements made it possible to:

1. To exclude deformation and destruction of sheets of the outer casing of the exhaust shafts during operation due to the compensation of the thermal expansion of the metal during the operation of the GPU in the vertical and horizontal planes.

2. Reduce the temperature of the external surface of the GPU to a safe level.

3. To reduce the transverse dimensions of the GPU exhaust device while increasing its strength.

4. The use of the walls of the hot and cold circuit in the construction of the walls made it possible during start-up, operation and shutdown of the unit to exclude uneven heating of the frame and to exclude uncoordinated deformations of rigidly connected parts (inner and outer shells), which can lead to the appearance of cracks in welded seams at startup and during shutdown of the GPU due to a sharp temperature drop.

5. Eliminate the destruction of the paint and varnish coating and the formation of foci of corrosion by reducing the temperature on the outer skin and excluding local zones with elevated temperatures.

6. It became possible to additionally install a galvanized painted sheet on the cold part of the walls of the elements of the exhaust devices of this design, which was not possible to use on the elements of the exhaust shaft with a high temperature on the outer skin due to the lack of resistance to high temperatures. This coating on profiled galvanized painted sheet is resistant to ultraviolet radiation, has good dirt-repelling properties, high corrosion resistance, resistance to sudden temperature fluctuations, which eliminates the operating costs of painting during the declared service life of the exhaust device.

7. Eliminate the discrepancy between the permissible sound pressure level in octave frequency bands and sound levels in working areas.

8. To ensure the reduction of the noise level due to the complex application of rectangular muffling plates along the exhaust gas flow and the increased thickness of the heat-insulating layer, and the use of vibration-resistant heat-insulating material made it possible to increase the service life of the exhaust shaft of the gas pumping unit.

Claims (16)

1. Exhaust device of a gas pumping unit, containing elements, which, in turn, consist of four walls or in the form of a round pipe, characterized in that all walls consist of a non-load-bearing hot part and a load-bearing cold part, interconnected by nodes that exclude the transmission of axial and radial forces arising from the thermal expansion of the non-supporting hot shell onto the supporting cold shell and reducing heat transfer between the interconnected shells. 2. The exhaust device of the gas pumping unit according to claim 1, characterized in that the load-bearing cold part of the section consists of a load-bearing frame made of bent shaped rolled steel and sheets of inner sheathing with a device on them for holding devices for sheathing the hot part, and the non-load-bearing hot part of the section consists of from sheets of inner lining of relatively thinner thickness, parts and assemblies that allow keeping the sheets of inner lining in the plane of the walls. 3. The exhaust device of the gas pumping unit according to claim 1 or 2, characterized in that the nodes that exclude the transfer of axial and radial forces arising from thermal expansion of the non-supporting hot shell to the supporting cold shell are made in the form of a compensator that compensates only for vertical movements, compensating only horizontal displacements and compensating and horizontal and vertical displacements. 4. The exhaust device of the gas pumping unit according to claim 1 or 2, characterized in that the thickness of the outer skin sheet is: δ ₁ = (2 ... 4) δ ₂ , where δ ₁ is the thickness of the outer skin sheet, δ ₂ - thickness of the inner skin sheet. 5. The exhaust device of the gas pumping unit according to claim 4 or 2, characterized in that the thickness of the inner lining sheet is: δ ₂ = 2 ... 4 mm. 6. The exhaust device of the gas pumping unit according to claim 1, characterized in that the thickness of the second layer of thermal insulation is: δ ₄ = (5 ... 11) δ ₃ , where δ ₃ is the thickness of the first layer of thermal insulation, δ ₄ - thickness of the second layer of thermal insulation. 7. The exhaust device of the gas pumping unit according to claim 6, characterized in that the thickness of the second layer of thermal insulation is: δ ₄ = 125 ... 275 mm. 8. The exhaust device of the gas pumping unit according to claim 1 or 2, characterized in that one of the elements is equipped with a silencer, which includes rectangular muffler plates.

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