GB2471666A - Heat recovery steam generator with heat pipes - Google Patents

Heat recovery steam generator with heat pipes Download PDF

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Publication number
GB2471666A
GB2471666A GB0911680A GB0911680A GB2471666A GB 2471666 A GB2471666 A GB 2471666A GB 0911680 A GB0911680 A GB 0911680A GB 0911680 A GB0911680 A GB 0911680A GB 2471666 A GB2471666 A GB 2471666A
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GB
United Kingdom
Prior art keywords
heat
exhaust
steam generator
steam
heat recovery
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB0911680A
Other versions
GB0911680D0 (en
Inventor
Dumitru Fetcu
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to GB0911680A priority Critical patent/GB2471666A/en
Publication of GB0911680D0 publication Critical patent/GB0911680D0/en
Priority to GB201011398A priority patent/GB2471771B/en
Publication of GB2471666A publication Critical patent/GB2471666A/en
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B1/00—Methods of steam generation characterised by form of heating method
    • F22B1/02—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers
    • F22B1/18—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being a hot gas, e.g. waste gas such as exhaust gas of internal-combustion engines
    • F22B1/1884—Hot gas heating tube boilers with one or more heating tubes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B1/00—Methods of steam generation characterised by form of heating method
    • F22B1/02—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers
    • F22B1/16—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being hot liquid or hot vapour, e.g. waste liquid, waste vapour
    • F22B1/165—Methods of steam generation characterised by form of heating method by exploitation of the heat content of hot heat carriers the heat carrier being hot liquid or hot vapour, e.g. waste liquid, waste vapour using heat pipes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
    • F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
    • F28D15/0275—Arrangements for coupling heat-pipes together or with other structures, e.g. with base blocks; Heat pipe cores
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F28F1/34—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending obliquely
    • F28F1/36—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending obliquely the means being helically wound fins or wire spirals
    • 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
    • F28F9/22—Arrangements for directing heat-exchange media into successive compartments, e.g. arrangements of guide plates
    • 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
    • F28F9/22—Arrangements for directing heat-exchange media into successive compartments, e.g. arrangements of guide plates
    • F28F2009/222—Particular guide plates, baffles or deflectors, e.g. having particular orientation relative to an elongated casing or conduit
    • F28F2009/226—Transversal partitions

Abstract

A steam generator has two sections 3,4 separated by a wall 13 through which finned heat pipes 1 in circular rows pass, the heat pipes 1 having one end in an exhaust flow in a vertical cylindrical space 2 of section 3 and the other end in water/steam in section 4, each heat pipe independently drawing in heat from the exhaust and transferring it to the water/steam. Exhaust inlet 5 of section 3 and outlet 26 of section 4 are on the same vertical axis, with exhaust gas flow radially through the heat pipes 1 being controlled by a baffle 9 and butterfly valve 10. Each heat pipe 1 is fixed to the wall 13 with a welded collar (29, fig 6), threaded nut and gasket or O-ring, and guided in holes in a bottom plate 15. Water is fed to the steam space by nozzles 25 in a ring shaped tube 24. Panels of the exhaust flow section 3 may be removable.

Description

Description
Heat recovery steam generator A heat recovery steam generator is a heat exchanger that recovers heat from a hot gas stream. It produces steam that can be used in a process or used to drive a steam turbine.
There are many types of heat recovery steam generators. The discussion below relates only to a single pressure heat recovery steam generator where steam is generated at single pressure level.
Current designs consist mainly of two sections: a steam drum (steam section) and an evaporator (evaporator section) where water is converted to steam. The evaporator section is usually made by a plurality of vertical or horizontal tubes placed in the exhaust duct and connected to the steam drum p'aced outside the exhaust duct. So, this type of steam generator is made of two parts -the evaporator and the steam drum -connected by pipes. Consequently a disadvantage appears because this type of construction, being made of two separate parts, is bulky and requires large space to be connected on an existing exhaust stack.
The heat transfer area of the classical high performance recovery steam generators is usually made by serrated or plain fin tubes. When these tubes are installed in large number another disadvantage appears: they are very difficult or even impossible to clean in order to preserve the initial thermodynamic and aerodynamic performances.
In addition, different heating of adjacent steam generator tubes may result in different thermal stress and accordingly may result in damage to the tubes.
There are a'so heat pipe based heat recovery steam generators made by a bundle of heat pipes having one end into the exhaust duct and the other end into a dished lid in which steam is collected. The disadvantages of these units are the high pressure drop on exhaust side, the impossibility of cleaning to preserve the exhaust side heat transfer performance and the impossibiUty to install directly on an existing vertical stack. Also, these units cannot have any built in system to allow the exhaust to continue to flow when there is no steam demand or when there is a reduced steam demand.
An object of this invention is to produce a heat recovery steam generator having both evaporator section and steam drum in the same unit, which may be installed directly on the exhaust stack thus offering a compact, reliable and cheaper construction.
A further object is to produce a heat recovery steam generator which can be easily cleaned on the exhaust side without uninstalling the unit. This feature becomes extremely important particularly when the exhaust side heat transfer area is made of finned tubes. It is widely known that even a small quantity of fouling at the fin base decreases the heat transfer performance by at least 30%.
A further object is to produce a heat recovery steam generator having no thermal stress in evaporator section. This feature becomes extremely important particularly when the steam generator is exposed to frequent shutdowns and startups.
A further object is to produce a heat recovery steam generator having a bunt in system to aUow the exhaust to continue to flow when there is no steam demand or when there is a reduced steam demand. This feature becomes very important particularly when the steam generator is installed on a high temperature exhaust stack connected with a process that cannot be stopped.
A further object is to produce a heat recovery steam generator having a proper water feeding system to match the heat pipes mode of operation.
A stifi further object is to produce a heat recovery steam generator having low pressure drop on exhaust side.
The above objects are obtained by a heat recovery steam generator having both evaporator section and steam section in the same cylinder but separated by a waU and being made by an arrangement of finned heat pipes placed, in a number of circular rows, around a vertical cylindrical space dedicated to exhaust flow and having one end in exhaust and the other end in steam, every heat pipe working independently by drawing in the exhaust heat and transferring it into steam.
In order to achieve a compact heat recovery steam generator able to be instaed direcUy on the exhaust stack the heat pipes are instaed in circular rows around a cylindrical space dedicated for exhaust flow, the exhaust inlet and outlet connections being on the same vertical axis. In this way the steam generator can be installed on every vertical existing stack, the installation requires far less room, becomes very simple and inexpensive, all the classical bulky stack connections being avoided.
In order to achieve a heat recovery steam generator which can be easily cleaned on exhaust side, the whole bundle of heat pipes is supported by a polar array of circular hollow tubes which act as pillars leaving the cylindrical walls free to remove. In this way, by easy removing the cylindrical panels, the heat pipe bundle on exhaust side is completely exposed to cleaning procedures.
In order to achieve a heat recovery steam generator having no thermal stress in evaporator section the heat pipes are fixed, by a special system, only in the separation plate both ends in exhaust and in steam being free to expand. The steam side end of the heat pipe is immersed free in the water-steam mixture. The exhaust side end of the heat pipe is also free being only guided by the corresponding hole in a bottom plate. In this way, when the steam generator is exposed to frequent shutdowns and startups no thermal stress appears in the heat transfer elements.
In order to achieve a heat recovery steam generator having a built in system to allow the exhaust to continue to flow when there is no steam demand or when there is a reduced steam demand a butterfly valve is installed on a baffle on the exhaust side.
When the butterfly valve is closed all the exhaust wifi pass through the circular bundle of heat pipes. Thus a maximum recovered heat is received from exhaust and transferred to steam. By opening the butterfly valve, it is only the desired rate of exhaust that will pass through the heat pipe bundle thus controlling the amount of heat received by the steam. The butterfly valve can be manual or can be actuated automatically to maintain the desired steam parameters.
In order to achieve a heat recovery steam generator having a proper water feeding system to match the heat pipes mode of operation the feed water enters continuously the steam side space and is dissipated there by means of a proper number of spraying nozzles installed on a tube having the shape of a ring.
In order to achieve a heat recovery steam generator having low pressure drop on exhaust side the heat pipes are arranged in circular rows around the cylindrical space dedicated to exhaust flow thus letting the exhaust to flow through a far larger number of heat pipes than in classical units.
The invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 shows a vertical cutaway through the steam generator.
Figure 2 shows a horizontal cutaway on exhaust side of the steam generator.
Figure 3 shows a top view from exhaust outlet connection 26.
Figure 4 shows a bottom view from exhaust inlet connection 5.
Figure 5 shows a side view of the steam generator.
Figure 6 shows a vertical cutaway of the heat pipes installing system in the separation plate.
Figure 1, shows a steam generator being made of a number of circular rows of finned heat pipes 1 placed around a cylindrical space 2 dedicated to exhaust flow and having one end in exhaust side 3 and the other end in steam side 4, every heat pipe working independently by drawing in the exhaust heat and transferring it into steam. The heat pipes 1 are fixed only in the separation plate 13 the end in steam side being free and the end in exhaust side being guided by the corresponding holes in bottom plate 15.
The exhaust, entering the unit through connection 5 made by loose flange 6 provided with a number of studs 7 welded on the bottom lid 8, is forced to flow radially through the bundle of heat pipes by the baffle 9 and may be controlled by a butterfly valve 10.
A special supporting structure made of some u shaped reinforcements 11, rectangular hollows 28 and circular hollows 12, which act as pillars, together with the separation plate 13, which acts as a beam, and together with the outer casing cylinder 14 form all together the exhaust side 3 of the unit.
The steam side 4 of the unit consists of the inner cylinder 16, the outer cynder 17, the dished d 18 and the corresponding part of the separation plate 13 welded together and instaed water tight on the separation plate by means of the flanges 19 and 20. The steam side space 4 is filled with saturated steam and a water-steam mixture having a certain level 21. Every heat pipe transfers the corresponding quantity of heat drawn in from the exhaust side 3 in this water-steam mixture.
The saturated steam obtained in this way is sent continuously to consumers through the connection 23. The feed water enters continuously the steam side space 4 through the flanged connection 22 and is dissipated there by means of a proper number of spraying nozzles 25 installed on a tube 24 having the shape of a ring. The cooled exhaust, still releasing the heat to steam through the cylinder 16, goes out of the unit through the connection 26 provided with a proper flange 27.
The exhaust connections 5 and 26 are on the same vertical axis.
Figure 2, shows a horizontal cutaway on exhaust side. The rectangular hollows 28 and circular hollows 12, placed in a polar array, sustain the whole bundle of heat pipes thus leaving the cylindrical walls of the outer casing 14 free to remove in order to expose the exhaust side heat transfer area to cleaning procedures.
Figure 3, shows a top view from exhaust outlet connection 26.
Figure 4, shows a view from exhaust inlet connection 5.
Figure 5, shows a side view of the steam generator.
Figure 6, shows a vertical cutaway of the installation system of the heat pipes in the separation plate which consists of a collar 29 welded 34 on a bare part of the finned tube 1, a threaded nut 30 designed to compress a special gasket 32 by a washer 31. By screwing in the threaded nut, a water tight separation between gas side and liquid side is realized allowing, at the same time, an easy installing or uninstalling of heat pipes.

Claims (6)

  1. C'aims 1. A heat recovery steam generator having both evaporator section and steam section in the same cynder but separated by a waU and being made by an arrangement of finned heat pipes placed in a number of cftcular rows around a vertical cylindrical space dedicated to exhaust flow and having one end in exhaust and the other end in steam, every heat pipe working independently by drawing in the exhaust heat and transferring it into steam.
  2. 2. A heat recovery steam generator according to daim 1, in which the feed water is added by means of a pipe having the shape of a ring placed above the water level and being fitted with a proper number of spraying nozzles.
  3. 3. A heat recovery steam generator according to claim 1, in which the heat pipes are instaUed in the separation waU by a system comprising a welded coUar, a threaded hole, a threaded nut, a washer and an 0-ring.
  4. 4. A heat recovery steam generator according to claim 1, in which the exhaust flow is forced by one or more baffles and the inetloutlet connections are placed on the same vertical axis.
  5. 5. A heat recovery steam generator according to claim 1, in which a butterfly valve is installed on a baffle on the exhaust side thus controlling, manually or automatical'y, the amount of heat received by the steam.
  6. 6. A heat recovery steam generator according to claim 1, in which a certain supported system is provided to create the possibility to have removable panels on the entire exhaust side.
GB0911680A 2009-07-07 2009-07-07 Heat recovery steam generator with heat pipes Withdrawn GB2471666A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB0911680A GB2471666A (en) 2009-07-07 2009-07-07 Heat recovery steam generator with heat pipes
GB201011398A GB2471771B (en) 2009-07-07 2010-07-07 Heat exchanger

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0911680A GB2471666A (en) 2009-07-07 2009-07-07 Heat recovery steam generator with heat pipes

Publications (2)

Publication Number Publication Date
GB0911680D0 GB0911680D0 (en) 2009-08-12
GB2471666A true GB2471666A (en) 2011-01-12

Family

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Family Applications (2)

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GB0911680A Withdrawn GB2471666A (en) 2009-07-07 2009-07-07 Heat recovery steam generator with heat pipes
GB201011398A Expired - Fee Related GB2471771B (en) 2009-07-07 2010-07-07 Heat exchanger

Family Applications After (1)

Application Number Title Priority Date Filing Date
GB201011398A Expired - Fee Related GB2471771B (en) 2009-07-07 2010-07-07 Heat exchanger

Country Status (1)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2490704A (en) * 2011-05-11 2012-11-14 ECONOTHERM UK Ltd Heat exchanger having two chambers in thermal communication through an array of heat pipes
ITTO20130373A1 (en) * 2013-05-10 2014-11-11 Argotec S R L DEVICE AND METHOD FOR THE OPTIMIZATION OF THERMAL TRANSFER IN A HEAT EXCHANGER
CN104727912A (en) * 2013-12-23 2015-06-24 现代自动车株式会社 System For Recycling Exhaust Heat From Internal Combustion Engine
CN104864376A (en) * 2015-05-28 2015-08-26 华北水利水电大学 Heat-pipe type falling film evaporation low-temperature waste heat utilization and water recovery equipment
GB2479867B (en) * 2010-04-26 2016-03-02 ECONOTHERM UK Ltd Heat exchanger

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH705622A2 (en) 2011-10-03 2013-04-15 Paul Mueller Means for recovering heat from hot exhaust gases and heat transfer module for use in such a device.
CN112902691B (en) * 2021-01-20 2023-05-26 国家能源集团国源电力有限公司 Waste water waste heat recovery system

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Publication number Priority date Publication date Assignee Title
DE2920577A1 (en) * 1979-05-21 1980-11-27 Gifa Planungsgesellschaft Fuer Heater tube fixture for bulkhead - uses bush cold welded to tube and secured by seal
US4488344A (en) * 1980-07-01 1984-12-18 Q-Dot Corporation Waste heat recovery system having thermal sleeve support for heat pipe
JPS60174402A (en) * 1984-02-17 1985-09-07 株式会社ササクラ Small-sized heat pipe type once-through boiler
WO2000062592A2 (en) * 1999-03-30 2000-10-26 Stephen Mongan Method and apparatus improving the efficiency of a steam boiler power generation system

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US3916844A (en) * 1974-07-29 1975-11-04 Combustion Eng Steam generator blowdown apparatus
US4621681A (en) * 1977-11-09 1986-11-11 Q-Dot Corporation Waste heat boiler
GB1571734A (en) * 1978-05-30 1980-07-16 Breese J Steam generators using heat pipes
JPS60153936A (en) * 1984-01-25 1985-08-13 Babcock Hitachi Kk Reactor with heat pipe
CZ288U1 (en) * 1992-04-03 1993-04-28 Vítkovice, A.S. Heat-exchange apparatus feeding system, particularly for steam generator

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2920577A1 (en) * 1979-05-21 1980-11-27 Gifa Planungsgesellschaft Fuer Heater tube fixture for bulkhead - uses bush cold welded to tube and secured by seal
US4488344A (en) * 1980-07-01 1984-12-18 Q-Dot Corporation Waste heat recovery system having thermal sleeve support for heat pipe
JPS60174402A (en) * 1984-02-17 1985-09-07 株式会社ササクラ Small-sized heat pipe type once-through boiler
WO2000062592A2 (en) * 1999-03-30 2000-10-26 Stephen Mongan Method and apparatus improving the efficiency of a steam boiler power generation system

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2479867B (en) * 2010-04-26 2016-03-02 ECONOTHERM UK Ltd Heat exchanger
GB2490704A (en) * 2011-05-11 2012-11-14 ECONOTHERM UK Ltd Heat exchanger having two chambers in thermal communication through an array of heat pipes
ITTO20130373A1 (en) * 2013-05-10 2014-11-11 Argotec S R L DEVICE AND METHOD FOR THE OPTIMIZATION OF THERMAL TRANSFER IN A HEAT EXCHANGER
WO2014181304A1 (en) * 2013-05-10 2014-11-13 Argotec S.R.L. Device and method for optimization of heat transfer in a heat exchanger
CN104727912A (en) * 2013-12-23 2015-06-24 现代自动车株式会社 System For Recycling Exhaust Heat From Internal Combustion Engine
EP2886820A1 (en) * 2013-12-23 2015-06-24 Hyundai Motor Company System of recycling exhaust heat from internal combustion engine
US9745881B2 (en) 2013-12-23 2017-08-29 Hyundai Motor Company System for recycling exhaust heat from internal combustion engine
CN104727912B (en) * 2013-12-23 2019-02-19 现代自动车株式会社 System for recycling the waste heat from internal combustion engine
CN104864376A (en) * 2015-05-28 2015-08-26 华北水利水电大学 Heat-pipe type falling film evaporation low-temperature waste heat utilization and water recovery equipment
CN104864376B (en) * 2015-05-28 2017-04-26 华北水利水电大学 Heat-pipe type falling film evaporation low-temperature waste heat utilization and water recovery equipment

Also Published As

Publication number Publication date
GB2471771A (en) 2011-01-12
GB201011398D0 (en) 2010-08-18
GB0911680D0 (en) 2009-08-12
GB2471771B (en) 2013-12-11

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