CN110260292A - A kind of boiler water wall augmentation of heat transfer pipe with spoiler - Google Patents
A kind of boiler water wall augmentation of heat transfer pipe with spoiler Download PDFInfo
- Publication number
- CN110260292A CN110260292A CN201910652113.2A CN201910652113A CN110260292A CN 110260292 A CN110260292 A CN 110260292A CN 201910652113 A CN201910652113 A CN 201910652113A CN 110260292 A CN110260292 A CN 110260292A
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- Prior art keywords
- spoiler
- tube body
- heat transfer
- rib
- internal
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 24
- 230000003416 augmentation Effects 0.000 title claims abstract description 19
- 229910001220 stainless steel Inorganic materials 0.000 claims abstract description 4
- 239000010935 stainless steel Substances 0.000 claims abstract description 4
- 239000000758 substrate Substances 0.000 claims abstract description 4
- 239000000463 material Substances 0.000 claims description 3
- 239000012530 fluid Substances 0.000 abstract description 24
- 239000007788 liquid Substances 0.000 abstract description 2
- 239000003245 coal Substances 0.000 description 5
- 238000001816 cooling Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 241000791841 Alectis ciliaris Species 0.000 description 1
- 241000826860 Trapezium Species 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000005755 formation reaction Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 230000003134 recirculating effect Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 230000005619 thermoelectricity Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B37/00—Component parts or details of steam boilers
- F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
- F22B37/10—Water tubes; Accessories therefor
- F22B37/101—Tubes having fins or ribs
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
- F28F9/24—Arrangements for promoting turbulent flow of heat-exchange media, e.g. by plates
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fluid Mechanics (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
The invention discloses a kind of boiler water wall augmentation of heat transfer pipe with spoiler, including tube body, along the spoiler of tube body axial direction arrangement and along the internal-rib of tube body axial direction screw arrangement.Wherein spoiler is formed using stainless steel substrates twisting, and windup-degree is 90 °, and windward side is welded on inboard wall of tube body, and is in axial direction arranged in tube body with the distance of 1000~1300mm of interval；The shape in internal-rib section is non-isosceles trapezoid, and bottom surface is smoothly connected with inboard wall of tube body face, and the angle α of side and bottom surface is 60~70 °, and β is 20~30 °.The present invention is in such a way that spoiler is matched with non-isosceles trapezoid section internal-rib, increase the heat transfer efficiency between near wall fluid and mainstream fluid, reduce the generation of the leeward side liquid eddy flow of internal-rib, reduce local temperature, the heat transfer property of riffled tube is improved on the whole, it is ensured that boiler water wall safe operation.
Description
Technical field
The present invention relates to boiler water-wall tube enhanced heat exchange fields, and in particular to a kind of boiler water cooling with spoiler
Wall augmentation of heat transfer pipe.
Background technique
Non-renewable energy is based on coal and is mostly coal inferior, wherein to occupy coal total for the coal amount consumed due to power generation
The ratio of amount is very huge.Compared with traditional thermoelectricity technology, ultra supercritical Combustion technology of circulating fluidized has high-efficient, coal
It plants many advantages, such as adaptable and pollutant emission is few and is widely used.In order to guarantee that ultra supercritical recirculating fluidized bed is transported
Capable stability and safety, water-cooling wall recommends the generation that film boiling is postponed using riffled tube, thus utmostly
Avoid the perils such as booster.
However, the internal-rib cross sectional shape of riffled tube used by traditional supercritical boiler water-cooling wall is mostly rectangle or waits
Waist is trapezoidal, and due to the cyclonic action of internal-rib, fluid is macro phenomena such as the leeward side of internal-rib reduces even flow stagnation there are flow velocity
Sight shows as internal-rib leeward side root temperature and is apparently higher than internal-rib head temperature, be easy to cause riffled tube wall surface local temperature mistake
It is high and be damaged.In addition, traditional internal-rib only enhances flowing and heat exchange situation at tube body near wall, and have ignored in
Heat exchanger effectiveness between heart fluid.Therefore, designing one kind, to can be avoided internal-rib leeward side root temperature excessively high and improve wall surface
The water-cooling wall riffled tube of heat transfer efficiency between place's fluid and core flow seems particularly significant.
By retrieval, Chinese patent (CN202852785U) discloses a kind of boiler water wall reinforcing biography with spoiler
Heat pipe, including tube body and thread, thread arrange that thread is transversal in tube body along inboard wall of tube body in a manner of being threadingly advanced
Shape on face be it is trapezoidal, the distance of trapezium base to the two neighboring thread center line of each thread is limited toIn the range of, wherein P is the screw pitch of thread, and S is the top width of thread.The patent exists
The flow resistance of riffled tube is reduced to a certain extent, but it is higher there is no internal-rib leeward side root local temperature is improved
Problem does not account for the problem of improving heat transfer efficiency between near wall fluid and core flow yet.
Chinese patent (CN206369496U) discloses the wide load with arc-shaped transition section fin with spoiler
Boiler water wall augmentation of heat transfer pipe, including tube body and the internal screw thread fin arranged in the shape of a spiral in inboard wall of tube body face, wherein interior spiral shell
Line fin cross sectional shape is isosceles trapezoid, and the joint face of side and top and bottom is arc section.The patent is in certain journey
On degree strengthen riffled tube heat exchange and reduce flow resistance, but equally also without improve riffled tube local temperature it is higher with
And the problem of near wall fluid and mainstream fluid heat transfer efficiency.
Summary of the invention
The present invention overcomes original technology insufficient, proposes a kind of boiler water wall augmentation of heat transfer pipe with spoiler, uses
Spoiler and non-isosceles trapezoid section internal rib formations can improve the higher phenomenon of internal-rib leeward side root temperature, improve water cooling
Wall safety in operation, and the mixing between near wall fluid and mainstream fluid can be reinforced, heat transfer coefficient between the two is improved,
Enhance heat-transfer capability.
The present invention solves technical solution used by prior art problem:
A kind of boiler water wall augmentation of heat transfer pipe with spoiler containing spoiler Yu non-isosceles trapezoid section internal-rib,
Including tube body, along the spoiler of tube body axial direction arrangement and along the internal-rib of tube body axial direction screw arrangement；The flow-disturbing
Piece is formed by sheet material twisting, the axially spaced setting in tube body of multiple spoilers, and windward and in tube body of each spoiler
Wall connection；The internal-rib cross sectional shape is non-isosceles trapezoid.
The spoiler is formed using stainless steel substrates twisting, and windup-degree is 90 °；.
The spoiler windward side is welded on inboard wall of tube body, and in tube body in axial direction with interval 1000~
The distance of 1300mm is arranged.
The spoiler windward side height a is greater than leeward side height b.
The spoiler windward side height a should be slightly less than internal diameter of tube body D, and leeward side height b is 1/3a；.
The flow-disturbing leaf length L is 400~500mm, and thickness s is 3~5mm；.
The internal-rib windward side side length of non-isosceles trapezoid is less than leeward side length.
The internal-rib cross sectional shape of non-isosceles trapezoid is non-isosceles trapezoid, and bottom surface smoothly connects with inboard wall of tube body face
It connects；.
The long w of internal-rib bottom surface is 4~6mm, and high H is 0.9~1.2mm, the angle α of side and bottom surface is 60~
70 °, β is 20~30 °；.
The internal-rib helix angle γ is 30~50 °, and intercept P is 15~25mm.
Compared with prior art, the beneficial effects of the present invention are:
The present invention by tube body, along the spoiler of tube body axial direction arrangement and along the non-etc. of tube body axial direction screw arrangement
Waist trapezoid cross section spiral internal-rib three parts composition, the side that the present invention uses spoiler to match with non-isosceles trapezoid section internal-rib
Formula increases the heat transfer efficiency between near wall fluid and mainstream fluid, reduces the generation of the leeward side liquid eddy flow of internal-rib, i.e.,
Local temperature is reduced, improves the heat transfer property of riffled tube on the whole, it is ensured that boiler water wall safe operation.Wherein disturb
The effect of flow is to reinforce the mixing between near wall fluid and mainstream fluid, improves the heat transfer efficiency of the two, make at wall surface
Heat can be taken away as early as possible by mainstream fluid, in order to avoid cause hot stack and cause wall surface temperature excessively high；In addition, using non-isosceles
Trapezoid cross section spiral internal-rib can not only increase the heat exchange area in inboard wall of tube body face, while its cyclonic action can force fluid to revolve
Turn, destroy fluid boundary layer near wall, to improve the heat transfer property in inboard wall of tube body face, non-isosceles trapezoid section is due to its back
The included angle of wind side and bottom surface is smaller, it is possible to reduce the appearance being vortexed herein further increases the heat transfer in inboard wall of tube body face
Performance, the phenomenon for avoiding local temperature excessively high occur.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of boiler water wall augmentation of heat transfer pipe of the present invention with spoiler；
Fig. 2 be Fig. 1 along A-A to sectional view；
Fig. 3 is spoiler structural schematic diagram；
Fig. 4 is the schematic cross-section of non-isosceles trapezoid section internal-rib.
Specific embodiment
The invention will be further described with reference to the accompanying drawing and by specific embodiment, and following embodiment is descriptive
, it is not restrictive, this does not limit the scope of protection of the present invention.
As depicted in figs. 1 and 2, a kind of boiler water wall augmentation of heat transfer pipe with spoiler of the present invention, including tube body 1,
Along the spoiler 2 of tube body axial direction arrangement and along the internal-rib 3 of tube body axial direction screw arrangement.Spoiler 2 is by sheet material twisting
It forms, the axially spaced setting in tube body 2 of multiple spoilers 2, and each spoiler 2 is connect with 1 inner wall of tube body windward；Institute
3 cross sectional shape of internal-rib stated is non-isosceles trapezoid.
As shown in figure 3, spoiler 2 is formed using stainless steel substrates twisting, windup-degree is 90 °.
As shown in Figure 3, it is preferable that 2 windward side of spoiler is welded on 1 inner wall of tube body, and in tube body 1 in axial direction with
It is spaced the distance arrangement of 1000~1300mm；
As shown in Figure 3, it is preferable that 2 windward side height a of spoiler should be slightly less than 1 internal diameter D of tube body, and leeward side height b is
As shown in Figure 3, it is preferable that 2 length L of spoiler is 400~500mm, and thickness s is 3~5mm.
As shown in Figure 4, it is preferable that 3 cross sectional shape of internal-rib is non-isosceles trapezoid, and its bottom surface and 1 inner wall of tube body are flat
Slip；
As shown in Figure 4, it is preferable that the long w of 3 bottom surface of internal-rib is 4~6mm, and high H is 0.9~1.2mm, side and bottom surface
Angle α be 60~70 °, β be 20~30 °；
As shown in Figure 4, it is preferable that 3 helix angle γ of internal-rib is 30~50 °, and intercept P is 15~25mm.
The present invention overcomes in original technology that heat transfer effect is poor between near wall fluid and mainstream fluid, internal-rib leeward side part
The higher problem of temperature, the form of non-isosceles trapezoid section internal-rib is cooperated using spoiler, preferably solves the above problem, is mentioned
The high heat transfer efficiency of riffled tube entirety, it is ensured that the safety in operation of boiler water wall.
Effect of the present invention are as follows: by tube body, along the spoiler of tube body axial direction arrangement and along tube body axial direction spiral cloth
The non-isosceles trapezoid section spiral internal-rib three parts composition set, wherein the effect of spoiler is to reinforce near wall fluid and mainstream
Mixing between fluid improves the heat transfer efficiency of the two, so that the heat at wall surface is taken away as early as possible by mainstream fluid, Yi Mianzao
Cause wall surface temperature excessively high at hot stack；In addition, can not only be increased in tube body using non-isosceles trapezoid section spiral internal-rib
The heat exchange area of wall surface, while its cyclonic action can force fluid rotary, fluid boundary layer near wall be destroyed, to improve
The heat transfer property in inboard wall of tube body face, non-isosceles trapezoid section can subtract since the included angle of its leeward side and bottom surface is smaller
Few appearance being vortexed herein, further increases the heat transfer property in inboard wall of tube body face, and the phenomenon for avoiding local temperature excessively high occurs.
More than, only presently preferred embodiments of the present invention is not limited only to practical range of the invention, all according to the scope of the invention
The content equivalence changes and modification done, all should be technology scope of the invention.
Claims (10)
1. a kind of boiler water wall augmentation of heat transfer pipe with spoiler, which is characterized in that including tube body (1), along tube body (1) axis
To the spoiler (2) of direction arrangement and along the internal-rib (3) of tube body (1) axial direction screw arrangement；The spoiler (2) is by piece
Material twisting forms, multiple spoiler (2) axially spaced settings in tube body (1), and each spoiler (2) windward with tube body
(1) inner wall connects；Internal-rib (3) cross sectional shape is non-isosceles trapezoid.
2. a kind of boiler water wall augmentation of heat transfer pipe with spoiler according to claim 1, which is characterized in that described
Spoiler (2) formed using stainless steel substrates twisting, windup-degree is 90 °.
3. a kind of boiler water wall augmentation of heat transfer pipe with spoiler according to claim 1, which is characterized in that described
Spoiler (2) in axial direction arranged with the distance of 1000~1300mm of interval in the tube body (2).
4. a kind of boiler water wall augmentation of heat transfer pipe with spoiler according to claim 1, which is characterized in that described
Spoiler (2) windward side height a be greater than leeward side height b.
5. a kind of boiler water wall augmentation of heat transfer pipe with spoiler according to claim 4, which is characterized in that described
Spoiler (2) windward side height a be slightly less than tube body (1) internal diameter D, leeward side height b is
6. a kind of boiler water wall augmentation of heat transfer pipe with spoiler according to claim 1, which is characterized in that described
Spoiler (2) length L be 400~500mm, thickness s be 3~5mm.
7. a kind of boiler water wall augmentation of heat transfer pipe with spoiler according to claim 1, which is characterized in that non-etc.
The trapezoidal internal-rib of waist (3) windward side side length is less than leeward side length.
8. a kind of boiler water wall augmentation of heat transfer pipe with spoiler according to claim 1, which is characterized in that non-etc.
The trapezoidal internal-rib of waist (3) bottom surface is smoothly connected with tube body (1) inner wall.
9. a kind of boiler water wall augmentation of heat transfer pipe with spoiler according to claim 1, which is characterized in that described
Internal-rib (3) long w of bottom surface be 4~6mm, high H is 0.9~1.2mm, and the angle α of side and bottom surface is 60~70 °, β 20
~30 °.
10. a kind of boiler water wall augmentation of heat transfer pipe with spoiler according to claim 1, which is characterized in that institute
Internal-rib (3) the helix angle γ stated is 30~50 °, and intercept P is 15~25mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910652113.2A CN110260292A (en) | 2019-07-18 | 2019-07-18 | A kind of boiler water wall augmentation of heat transfer pipe with spoiler |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910652113.2A CN110260292A (en) | 2019-07-18 | 2019-07-18 | A kind of boiler water wall augmentation of heat transfer pipe with spoiler |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110260292A true CN110260292A (en) | 2019-09-20 |
Family
ID=67926981
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910652113.2A Pending CN110260292A (en) | 2019-07-18 | 2019-07-18 | A kind of boiler water wall augmentation of heat transfer pipe with spoiler |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110260292A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112856477A (en) * | 2021-01-18 | 2021-05-28 | 哈电发电设备国家工程研究中心有限公司 | Water-cooled wall internal thread tube panel and processing method thereof |
| CN114750965A (en) * | 2022-06-15 | 2022-07-15 | 中国空气动力研究与发展中心设备设计与测试技术研究所 | Cooling device based on bionic veins |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09145006A (en) * | 1995-11-21 | 1997-06-06 | Mitsubishi Heavy Ind Ltd | Boiler tube |
| CN102997740A (en) * | 2011-09-09 | 2013-03-27 | 杨伟光 | Novel reinforced tube for boiling and heat exchange in tube |
| CN202928429U (en) * | 2012-10-19 | 2013-05-08 | 上海大俊凯电器科技有限公司 | Metal heat transfer pipe coil |
| CN103542759A (en) * | 2012-07-12 | 2014-01-29 | 中国石油天然气股份有限公司 | Heat exchanging pipe with reinforced heat transfer elements |
| CN105806127A (en) * | 2016-05-03 | 2016-07-27 | 西安交通大学 | Boiler water-cooled wall inner threaded pipe with streamline-section inner ribs |
| CN105849463A (en) * | 2013-12-27 | 2016-08-10 | 三菱日立电力系统株式会社 | Heat transfer tube, boiler, and steam turbine facility |
| CN105890405A (en) * | 2016-05-05 | 2016-08-24 | 无锡科技职业学院 | Double-slot type strengthened pipe type heat exchanger |
| CN206369496U (en) * | 2016-12-19 | 2017-08-01 | 西安交通大学 | Wide load boiler water-cooling wall riffled tube with arc-shaped transition section fin |
| CN107131785A (en) * | 2017-06-17 | 2017-09-05 | 福建德兴节能科技有限公司 | High-efficiency cyclone flow spoiler |
| CN109724444A (en) * | 2017-10-27 | 2019-05-07 | 中国石油化工股份有限公司 | Heat-transfer pipe and pyrolysis furnace |
-
2019
- 2019-07-18 CN CN201910652113.2A patent/CN110260292A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09145006A (en) * | 1995-11-21 | 1997-06-06 | Mitsubishi Heavy Ind Ltd | Boiler tube |
| CN102997740A (en) * | 2011-09-09 | 2013-03-27 | 杨伟光 | Novel reinforced tube for boiling and heat exchange in tube |
| CN103542759A (en) * | 2012-07-12 | 2014-01-29 | 中国石油天然气股份有限公司 | Heat exchanging pipe with reinforced heat transfer elements |
| CN202928429U (en) * | 2012-10-19 | 2013-05-08 | 上海大俊凯电器科技有限公司 | Metal heat transfer pipe coil |
| CN105849463A (en) * | 2013-12-27 | 2016-08-10 | 三菱日立电力系统株式会社 | Heat transfer tube, boiler, and steam turbine facility |
| CN105806127A (en) * | 2016-05-03 | 2016-07-27 | 西安交通大学 | Boiler water-cooled wall inner threaded pipe with streamline-section inner ribs |
| CN105890405A (en) * | 2016-05-05 | 2016-08-24 | 无锡科技职业学院 | Double-slot type strengthened pipe type heat exchanger |
| CN206369496U (en) * | 2016-12-19 | 2017-08-01 | 西安交通大学 | Wide load boiler water-cooling wall riffled tube with arc-shaped transition section fin |
| CN107131785A (en) * | 2017-06-17 | 2017-09-05 | 福建德兴节能科技有限公司 | High-efficiency cyclone flow spoiler |
| CN109724444A (en) * | 2017-10-27 | 2019-05-07 | 中国石油化工股份有限公司 | Heat-transfer pipe and pyrolysis furnace |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112856477A (en) * | 2021-01-18 | 2021-05-28 | 哈电发电设备国家工程研究中心有限公司 | Water-cooled wall internal thread tube panel and processing method thereof |
| CN112856477B (en) * | 2021-01-18 | 2022-05-27 | 哈电发电设备国家工程研究中心有限公司 | Water-cooled wall internal thread tube panel and processing method thereof |
| CN114750965A (en) * | 2022-06-15 | 2022-07-15 | 中国空气动力研究与发展中心设备设计与测试技术研究所 | Cooling device based on bionic veins |
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