WO2012134926A2 - Method of controlling drum temperature transients - Google Patents
Method of controlling drum temperature transients Download PDFInfo
- Publication number
- WO2012134926A2 WO2012134926A2 PCT/US2012/030035 US2012030035W WO2012134926A2 WO 2012134926 A2 WO2012134926 A2 WO 2012134926A2 US 2012030035 W US2012030035 W US 2012030035W WO 2012134926 A2 WO2012134926 A2 WO 2012134926A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- evaporator
- pump
- fluid
- drum
- steam drum
- Prior art date
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B35/00—Control systems for steam boilers
-
- 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
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B35/00—Control systems for steam boilers
- F22B35/007—Control systems for waste heat boilers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B35/00—Control systems for steam boilers
- F22B35/02—Control systems for steam boilers for steam boilers with natural convection circulation
-
- 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
Definitions
- Disclosed herein is a method of controlling drum temperature transients in an evaporator system in a heat recovery steam generator. More specifically, disclosed herein is a method of using temporary forced circulation during startup to control drum temperature transients in a heat recovery steam generator.
- Heat recovery steam generators generally comprise three major components: an evaporator, a superheater and an economizer. The different components are put together to meet the operating requirements of the unit. Some heat recovery steam generators may not have a superheater or may include additional components such as reheaters.
- FIG. 1 is a depiction of an exemplary prior art evaporator system 100 of a heat recovery steam generator that comprises an evaporator 102 and a steam drum 104.
- the steam drum 104 is in fluid communication with the evaporator 102.
- a natural circulation heat recovery steam generator either no flow or minimal flow is established until boiling begins in the evaporator 102. This generally results in a very rapid rise in the steam drum 104 temperature.
- the water temperature inside the steam drum 104 can rise from 15°C to 100°C in less than 10 minutes. This produces a large thermal gradient and hence compressive stress in the steam dmm 104 wall. As the pressure in the steam drum 104 increases, the temperature gradient through the drum wall is reduced and consequently the stress due to pressure becomes the dominant stress in the drum.
- the stress due to pressure (with increased pressure in the steam drum 104) is a tensile stress.
- the stress range for the dram is determined by the difference between the final tensile stress at full load (pressure) and the initial compressive thermal stress. Boiler Design Codes (such as ASME and EN) impose limits on the stress at design pressure.
- Some codes such as for example EN12952-3, also include limits on the permissible stress range for a startup-shutdown cycle. These limits are intended to protect against fatigue damage and phenomena such as cracking of the magnetite layer that forms on the surface of the steel at operating temperature.
- the wall thickness of the steam drum 104 is also increased to ensure that the tensile stress in the drum shell at design conditions does not exceed allowable stress limits specified in the design Codes.
- a method comprising creating a temporary pressure gradient during start-up of an evaporator system, where the evaporator system comprises an evaporator; a drum; and a pump; where the evaporator, the drum and the pump are in fluid communication with each other; transporting a fluid from the evaporator to the drum prior to the fluid reaching its boiling point in the evaporator; and circulating the fluid through the evaporator system via natural circulation after the fluid has reached its boiling point in the evaporator.
- Figure 1 is a prior art depiction of the evaporator system
- Figure 2 is a depiction of an exemplary embodiment of the evaporator system of the present invention.
- Figure 3 is another depiction of an exemplary embodiment of the evaporator system of the present invention.
- first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
- relative terms such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element's relationship to another element as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in one of the figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements. The exemplary term “lower,” can therefore, encompasses both an orientation of “lower” and “upper,” depending on the particular orientation of the figure.
- Exemplary embodiments are described herein with reference to cross sectional illustrations that are schematic illustrations of idealized embodiments. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features.
- an evaporator system that comprises a pump for circulating heated fluid from the evaporator to the steam drum.
- the pump provides circulation during start-up to initiate heating of the steam drum, which reduces the rate of temperature change in the drum. This reduction in the rate of temperature change in the steam drum causes reduced thermal stresses in the drum.
- the fluid is water.
- the pump may be a centrifugal pump, a jet-pump pump, or the like, and its purpose is to provide a pressure gradient in the evaporator system that promotes fluid circulation from the evaporator to the steam drum before fluid (e.g., water) present in the evaporator begins to boil.
- the pump produces a lower pressure in the steam drum in relation to the evaporator before fluid present in the evaporator begins to boil.
- fluid from the evaporator is drawn into the steam drum causing the drum to heat up gradually. The gradual heating takes place until the fluid in the evaporator reaches the boiling point, at which point the pump may be shut off or isolated. After the pump is shut off, natural circulation promotes circulation of the fluid in the evaporator system.
- the pump therefore operates for a short period of time, until the steam dram reaches the temperature of the boiling fluid. This allows for a pump that is smaller in size
- Wl 0/034-0 4 than other comparative pumps that are normally used. It also reduces stress in the wall of the steam drum.
- an evaporator system 200 of the present invention comprises an evaporator 202, a steam drum 204 and a pump 206.
- the pump 206 is in fluid communication with the steam drum 204 and the evaporator 202.
- the pump 206 lies downstream of the steam drum 204.
- the steam drum lies downstream of the evaporator 202.
- a one-way check valve 208 Disposed across the inlet and outlet to the pump 206 is a one-way check valve 208.
- the check valve 208 permits only fluid flow from the steam drum 204 downstream to the evaporator 202 via the pump 206.
- the check valve further permits only fluid flow from the evaporator 202 downstream to the steam drum 204.
- the pump 206 has a first valve 210 and a second valve 212 disposed upstream and downstream of it respectively.
- the first valve 210 and the second valve 212 can isolate the pump 206 from the evaporator system 200 when desired.
- the first valve 210 and the second valve 212 can be electrically, pneumatically or manually activated.
- the pump 206 in one method of operation of the evaporator system 200, is used to circulate fluid from the evaporator 202 to the steam drum 204 during start up of the heat recovery steam generator to eliminate the rapid drum temperature rise that would normally occur in a natural circulation heat recovery steam generator.
- the pump 206 is isolated and the evaporator 202 runs under natural circulation.
- the pump 206 can be isolated after start-up, it does not have to be sized for full flow load, pressure and temperature. This reduces the cost of the pump 206 when compared with comparative pumps that are used for full time circulation.
- the evaporator system 200 comprises a jet-pump 306 (eductor) that creates a pressure gradient in the evaporator system that promotes fluid circulation from the evaporator 202 to the steam drum 204 before fluid (e.g., water) present in the evaporator 202 begins to boil.
- the jet-pump 306 produces a lower pressure in the steam drum in relation to the evaporator before the fluid present in the evaporator begins to boil.
- the jet-pump 306 creates low pressure in a downcomer 308 that is in fluid communication with the steam drum 204 as a result of which fluid is drawn into the steam drum 204 from the evaporator 202.
- High velocity fluid flow in the narrow downcomer 308 induces a low pressure in the downcomer 308 relative to the steam drum 204, which in turn
- W10/034-0 5 causes flow in the downcomer 308.
- the steam drum 204 is at a lower pressure than the evaporator, which causes the fluid to flow from the evaporator 202 to the steam drum 204.
- low pressure created in the downcomer 308 by the operation of the jet-pump 306 drives the circulation of fluid from the evaporator 202 to the steam drum 204.
- the jet-pump 306 is in fluid communication with a first valve 310 and a second valve 312.
- the first valve 310 is used to control the flow of feed water into the steam drum 204, while the second valve 312 is used to isolate the jet-pump 306 from the
- the jet-pump 306 of the Figure 3 functions in a manner similar to the pump 206 of the Figure 2 in that it permits a temporary fluid flow from the evaporator 202 to the steam drum 204 before the fluid present in the evaporator 202 begins to boil.
- the use of a pump for temporary circulation of fluid to the steam drum has a number of advantages. These include using a pump that is smaller in size than other comparative pumps that are nomially used. It also reduces stress in the wall of the steam drum and permits the use of steam drums with larger wall thickness than those that are currently used in evaporator systems that do not employ temporary circulation. This in turn allows operation of the steam drum at higher pressures or greater numbers of stop-start cycles.
Abstract
Description
Claims
Priority Applications (9)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP12713496.3A EP2691700B1 (en) | 2011-03-28 | 2012-03-22 | Method of controlling drum temperature transients |
CA2831727A CA2831727A1 (en) | 2011-03-28 | 2012-03-22 | Method of controlling drum temperature transients |
CN201280016172.7A CN103518099B (en) | 2011-03-28 | 2012-03-22 | Method of controlling drum temperature transients |
JP2014502633A JP6068434B2 (en) | 2011-03-28 | 2012-03-22 | How to control drum temperature transients |
AU2012237667A AU2012237667B2 (en) | 2011-03-28 | 2012-03-22 | Method of controlling drum temperature transients |
MX2013011638A MX2013011638A (en) | 2012-03-22 | 2012-03-22 | Method of controlling drum temperature transients. |
KR1020137028001A KR20130143723A (en) | 2011-03-28 | 2012-03-22 | Method of controlling drum temperature transients |
RU2013147828/06A RU2575518C2 (en) | 2011-03-28 | 2012-03-22 | Control over variable temperatures of drum |
IL228543A IL228543A0 (en) | 2011-03-28 | 2013-09-29 | Method of controlling drum temperature transients |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/073,230 | 2011-03-28 | ||
US13/073,230 US20120247406A1 (en) | 2011-03-28 | 2011-03-28 | Method of controlling drum temperature transients |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2012134926A2 true WO2012134926A2 (en) | 2012-10-04 |
WO2012134926A3 WO2012134926A3 (en) | 2013-08-22 |
Family
ID=45937619
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2012/030035 WO2012134926A2 (en) | 2011-03-28 | 2012-03-22 | Method of controlling drum temperature transients |
Country Status (9)
Country | Link |
---|---|
US (1) | US20120247406A1 (en) |
EP (1) | EP2691700B1 (en) |
JP (1) | JP6068434B2 (en) |
KR (1) | KR20130143723A (en) |
CN (1) | CN103518099B (en) |
AU (1) | AU2012237667B2 (en) |
CA (1) | CA2831727A1 (en) |
IL (1) | IL228543A0 (en) |
WO (1) | WO2012134926A2 (en) |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1927095A (en) * | 1927-01-03 | 1933-09-19 | Babcock & Wilcox Co | Triple circuit water tube boiler |
US2432885A (en) * | 1945-12-08 | 1947-12-16 | Tennessee Eastman Corp | Furnace |
GB1207688A (en) * | 1967-10-20 | 1970-10-07 | Head Wrightson & Co Ltd | Improvements in and relating to steam generating installations |
US4151813A (en) * | 1978-03-27 | 1979-05-01 | Foster Wheeler Energy Corporation | Jet pump in natural circulation fossil fuel fired steam generator |
AT392683B (en) * | 1988-08-29 | 1991-05-27 | Sgp Va Energie Umwelt | HEAT STEAM GENERATOR |
JPH0384301A (en) * | 1989-08-24 | 1991-04-09 | Toshiba Corp | Naturally circulating waste heat recovery boiler |
BE1005793A3 (en) * | 1992-05-08 | 1994-02-01 | Cockerill Mech Ind Sa | INDUCED CIRCULATION HEAT RECOVERY BOILER. |
JPH109502A (en) * | 1996-06-24 | 1998-01-16 | Babcock Hitachi Kk | Water tube boiler |
DE19638851C1 (en) * | 1996-09-21 | 1998-02-26 | Oschatz Gmbh | Steam generator |
JP5191361B2 (en) * | 2008-11-21 | 2013-05-08 | 株式会社日立製作所 | Liquid level control system. |
CN201436467U (en) * | 2009-05-21 | 2010-04-07 | 上海梅山钢铁股份有限公司 | Natural circulation structure of dry quenched coke boiler economizer |
-
2011
- 2011-03-28 US US13/073,230 patent/US20120247406A1/en not_active Abandoned
-
2012
- 2012-03-22 JP JP2014502633A patent/JP6068434B2/en active Active
- 2012-03-22 EP EP12713496.3A patent/EP2691700B1/en active Active
- 2012-03-22 CA CA2831727A patent/CA2831727A1/en not_active Abandoned
- 2012-03-22 CN CN201280016172.7A patent/CN103518099B/en active Active
- 2012-03-22 KR KR1020137028001A patent/KR20130143723A/en not_active Application Discontinuation
- 2012-03-22 WO PCT/US2012/030035 patent/WO2012134926A2/en active Application Filing
- 2012-03-22 AU AU2012237667A patent/AU2012237667B2/en not_active Ceased
-
2013
- 2013-09-29 IL IL228543A patent/IL228543A0/en unknown
Non-Patent Citations (1)
Title |
---|
None |
Also Published As
Publication number | Publication date |
---|---|
CA2831727A1 (en) | 2012-10-04 |
CN103518099A (en) | 2014-01-15 |
US20120247406A1 (en) | 2012-10-04 |
JP6068434B2 (en) | 2017-01-25 |
EP2691700A2 (en) | 2014-02-05 |
CN103518099B (en) | 2017-05-17 |
AU2012237667B2 (en) | 2015-08-27 |
KR20130143723A (en) | 2013-12-31 |
JP2014512505A (en) | 2014-05-22 |
WO2012134926A3 (en) | 2013-08-22 |
RU2013147828A (en) | 2015-05-10 |
IL228543A0 (en) | 2013-12-31 |
AU2012237667A1 (en) | 2013-10-17 |
EP2691700B1 (en) | 2021-03-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN101680651A (en) | Immediate response steam generating system and method | |
CN204962711U (en) | Supercritical unit or super supercritical unit do not have oxygen -eliminating device heat regenerative system | |
US20170098483A1 (en) | Heat exchange system and nuclear reactor system | |
US9494054B2 (en) | Auxiliary steam generator system for a power plant | |
CN101769222A (en) | Thermal hydro-turbine power generating device | |
US20160208657A1 (en) | Operating method for starting a once-through steam generator heated using solar thermal energy | |
CN107170487B (en) | The control system and method for the polycyclic inclined loop operation of the long-term low-power of road reactor | |
AU2012237667B2 (en) | Method of controlling drum temperature transients | |
RU2575518C2 (en) | Control over variable temperatures of drum | |
CN202851092U (en) | Circulating water start-up system of steam turbine | |
JP4349133B2 (en) | Nuclear power plant and operation method thereof | |
JP2016145828A (en) | Small sized nuclear power station | |
US20170306801A1 (en) | Method for shortening the start-up process of a steam turbine | |
CN103375324B (en) | A kind of method preventing phase modulation setting-out gas tank and safety valve malfunction | |
JOP20190309B1 (en) | Method and system for bringing a nuclear power plant into a safe state after extreme effect | |
RU2761108C1 (en) | Passive heat discharge system of the reactor plant | |
US20110056221A1 (en) | Active stress control during rapid shut down | |
JP7199323B2 (en) | steam turbine generator | |
CN114198738A (en) | High-temperature gas cooled reactor feed water heating system | |
CA2454559A1 (en) | Nuclear power plant | |
RU2413848C1 (en) | Thermal power station, mainly nuclear power station | |
JP2010223105A (en) | Steam turbine system and method and program for controlling the same | |
RU2655161C1 (en) | Single-loop nuclear power plant with a coolant under pressure | |
EP3460203B1 (en) | Steam turbine plant | |
JP2001091689A (en) | Starting method for supercritical pressure light water- cooled reactor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12713496 Country of ref document: EP Kind code of ref document: A2 |
|
ENP | Entry into the national phase |
Ref document number: 2831727 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1301005509 Country of ref document: TH |
|
ENP | Entry into the national phase |
Ref document number: 2014502633 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: MX/A/2013/011638 Country of ref document: MX |
|
ENP | Entry into the national phase |
Ref document number: 2012237667 Country of ref document: AU Date of ref document: 20120322 Kind code of ref document: A |
|
ENP | Entry into the national phase |
Ref document number: 20137028001 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2012713496 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2013147828 Country of ref document: RU Kind code of ref document: A |