US20110174240A1 - Controlling variables in boiler pressure vessels - Google Patents
Controlling variables in boiler pressure vessels Download PDFInfo
- Publication number
- US20110174240A1 US20110174240A1 US12/690,197 US69019710A US2011174240A1 US 20110174240 A1 US20110174240 A1 US 20110174240A1 US 69019710 A US69019710 A US 69019710A US 2011174240 A1 US2011174240 A1 US 2011174240A1
- Authority
- US
- United States
- Prior art keywords
- drum
- pressure vessel
- wall
- boiler pressure
- boiler
- 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.)
- Abandoned
Links
Images
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
- F22B37/22—Drums; Headers; Accessories therefor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K3/00—Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein
- F01K3/18—Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein having heaters
- F01K3/20—Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein having heaters with heating by combustion gases of main boiler
- F01K3/22—Controlling, e.g. starting, stopping
-
- 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
- F22B35/04—Control systems for steam boilers for steam boilers with natural convection circulation during starting-up periods, i.e. during the periods between the lighting of the furnaces and the attainment of the normal operating temperature of the steam boilers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B5/00—Steam boilers of drum type, i.e. without internal furnace or fire tubes, the boiler body being contacted externally by flue gas
- F22B5/04—Component parts thereof; Accessories therefor
Definitions
- the present application is generally directed to systems and methods for controlling variables in boiler pressure vessels. More particularly, the present application is directed to systems and methods for reducing stresses in the walls of boiler pressure vessels.
- a boiler pressure vessel (hereinafter “boiler”) is a closed vessel comprising a shell and containing a liquid that can be heated under controlled conditions using a fuel or hot gases.
- the shell is a drum (hereinafter “drum” or “boiler drum”) that is defined by one or more walls. Chemical energy contained in the fuel is converted into thermal energy, which heats the liquid in the boiler and causes it to vaporize. The mixture of liquid and vapor enters the drum.
- the walls of the drum are designed to withstand pressures exerted by the vaporized liquid.
- the vaporized liquid can be taken from the drum and used to provide work or as a source of heat.
- the drum is a steam drum utilized to separate steam from the water.
- the wall thickness is greater (as compared to boilers that operate at lower pressure and/or have small drum diameters) to maintain acceptable pressure stress levels. Increased wall thickness results in increased thermal stresses within the walls. High stresses within the walls of the drums also occur at various sites or penetrations that extend through the wall. Typical penetrations include nozzles and the like. Since the penetrations are points of weakness in the drum walls, the maximum operating pressure of the boiler is effectively restricted due to limitations imposed by the European Norm (EN) code on maximum stress ranges in boilers (and more particularly in boiler drums). The range of stress also limits the number of rapid startups that the boiler may be subjected to as well as the total number of startups over the life of the boiler.
- EN European Norm
- Thick-walled boiler drums are generally heated only on their inside surfaces, which results in temporary and uneven temperatures in the wall, particularly during the startup period. As the wall thickness increases, so does the temperature gradient through the wall. The induced thermal stress increases for a given rate of internal temperature change as the drum wall thickness increases. Over time, the wall heats up to a uniform temperature, thereby eliminating this type of thermal stress. The pressure stress then dominates. Such stresses due to thermal gradients and internal pressure, when applied and removed repeatedly, can cause crack initiation and growth in the component material. The need to limit stresses to prevent such cracks can effectively limit the rate of temperature change in the drum. By limiting the rate of temperature change, the operational flexibility (e.g., maximum pressures attainable) of the boiler is decreased. Such flexibility is desirable to provide for rapid start-ups to respond to changes in power demand.
- FIG. 1 illustrates a typical stress history for a steam drum during a boiler startup.
- Thermal stress that occurs early in the startup process is shown as diminishing as the temperature of the drum wall becomes more uniform as steady state operating conditions are approached. As steady state conditions are approached, the stress due to internal pressure dominates the thermal stress.
- the positive hoop stress tensile
- the negative stress due to through wall temperatures at start up and limits the rate or number of starts.
- a method of controlling stress in a boiler pressure vessel comprises limiting the diameter of a drum of the boiler pressure vessel and preheating at least a portion of the wall of the drum. Limiting the diameter of the drum allows pressure in the drum to be increased for a given mechanical stress. Furthermore, preheating the wall of the drum reduces peak thermally induced stresses in a material from which the drum is fabricated.
- a method of operating a boiler pressure vessel comprises applying local heating to a portion of the boiler pressure vessel prior to a startup operation of the boiler pressure vessel, during an operation of the boiler pressure vessel, and/or during a shutdown operation of the boiler pressure vessel. In applying local heating to the boiler pressure vessel, thermally induced stresses in the boiler pressure vessel are reduced.
- a method of controlling variables in a boiler pressure vessel comprises providing a steam drum of a boiler; controlling mechanical stress in a wall of the steam drum by limiting the diameter of the steam drum; and controlling thermal stress in the wall of the steam drum by heating at least a portion of the steam drum.
- the heating of the portion of the steam drum is effected by preheating penetrations in the steam drum and/or an area surrounding a penetration in the steam drum during at least one of a startup period and a shutdown period of the boiler pressure vessel.
- FIG. 1 is a graphical representation of a typical stress history for a steam drum
- FIG. 2 is a schematic representation of a vertical section of a steam drum of a boiler.
- FIG. 3 is a perspective view of a vertical section of a steam drum of a boiler.
- FIG. 2 one exemplary embodiment of a steam drum of a boiler is shown generally at 10 and is hereinafter referred to as “drum 10 ” or “steam drum 10 .”
- the drum 10 can be from a natural circulation boiler, an assisted circulation boiler, or any other type of boiler.
- the drum 10 is of an elongated cylindrical shape and has a wall 12 that is penetrated by nozzles 14 that receive a high temperature steam/liquid mixture and discharge this mixture into an annular space 16 between a drum liner or baffle 18 and an inner surface 15 of the wall 12 .
- the wall 12 also has an exterior surface 17 .
- the nozzles 14 may extend beyond the inner surface 15 of the wall ( FIG. 2 ) or they may terminate at the inner surface 15 ( FIG. 3 ).
- a liquid 26 such as, for example, water pools in the bottom of the drum 10 .
- One or more steam separating units 24 are located outside the volume enclosed by the baffle 18 . Steam from the steam/liquid mixture 34 and from the vaporization of the water 26 passes through a drying assembly 32 and is removed through an outlet 30 .
- the configuration of FIG. 2 is not limited to that as shown, as other configurations are possible.
- the nozzles 14 and the areas 15 a of the inner surface 15 of the wall 12 surrounding the nozzles 14 are affected by the steam/liquid mixture 34 .
- Temperature transients e.g., the movement of heat from one area to another
- the nozzles 14 and the areas 15 a surrounding the nozzles namely, the drum wall 12 and particularly at the inner surface 15
- Mechanical stresses such as hoop stress in the wall 12 of the drum 10 are also encountered as the result of pressure.
- Mechanical stress in the wall 12 is a function of various process variables, namely, the radius of the drum 10 , the thickness of the wall 12 , and the internal pressure of the drum 10 . This can be described by the equation:
- ⁇ m is the hoop stress of the drum
- P is the internal pressure
- R is the drum radius
- t is the drum wall thickness
- One approach to accommodating mechanical stress that is applicable to both natural circulation boilers and assisted circulation boilers with steam production greater than 50 kilogram per second (kg/s) to enable operation at higher pressures, which is desirable due to the resulting higher cycle efficiency, is to limit the thickness of the wall 12 of the drum 10 .
- the thickness of the wall 12 is limited by using a relatively small diameter steam drum, for example, a steam drum having an inside diameter of between about 1,000 millimeters (mm) and about 1,775 mm.
- mm millimeters
- Typical wall thicknesses could range from about 70 mm to about 150 mm.
- Thermal stresses within the wall 12 of the drum 10 also occur at the nozzles 14 or other penetrations through the wall 12 to the inner surface 15 as well as at the inner surfaces 15 a proximate the nozzles 14 .
- a localized high stress range area is shown at 20 .
- This localized high stress range area 20 is located on the inner surface 15 proximate the area at which the nozzle 14 penetrates the wall.
- the stress in this localized high stress range area 20 is at least twice the stress in any other area in the rest of the drum.
- One approach to applying local heating to accommodate thermal stress is to preheat the nozzles 14 and the area 15 a adjacent thereto (e.g., the inner surface area 15 a of the wall 12 in the area of the nozzle 14 ) prior to boiler startup when the drum 10 is at ambient pressure conditions.
- the local heating may be applied on the exterior surface 17 of the drum 10 proximate the area at which the nozzle 14 enters the drum 10 (e.g., area 17 a ). This would reduce the peak thermally induced stresses in a material from which the wall 12 of the drum 10 is fabricated that would otherwise limit the number of startups from ambient conditions or even prevent use of drum-type boilers above certain pressure ranges due to the EN code limits of stress ranges.
- Locally preheating of the nozzles 14 and/or the wall 12 may be used as an alternative to or in conjunction with limiting the diameter of the drum 10 .
- the approach is not limited to being undertaken at startup of the boiler, as the nozzles 14 and the wall 12 could be heated during a shutdown operation. In doing so, the rate at which heat is dissipated from the nozzles 14 and the wall 12 would be reduced, thereby reducing the thermally induced stresses in the material of the nozzles 14 and the wall 12 .
- the number of cold starts could potentially be limited to an absolute maximum in the specification (e.g., 300) as compared to an essentially unlimited number of cold starts with preheating.
- ⁇ t is the thermal stress
- T r is the rate of temperature change
- t is the drum wall thickness
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Control Of Steam Boilers And Waste-Gas Boilers (AREA)
- Pressure Vessels And Lids Thereof (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
A method of controlling stress in a boiler pressure vessel comprises limiting the diameter of a drum (10) of the boiler pressure vessel and preheating at least a portion of the wall (12) of the drum (10). Limiting the diameter of the drum (10) allows pressure in the drum (10) to be increased for a given mechanical stress. Furthermore, preheating the wall (12) of the drum (10) reduces peak thermally induced stresses in a material from which the drum (10) is fabricated.
Description
- The present application is generally directed to systems and methods for controlling variables in boiler pressure vessels. More particularly, the present application is directed to systems and methods for reducing stresses in the walls of boiler pressure vessels.
- A boiler pressure vessel (hereinafter “boiler”) is a closed vessel comprising a shell and containing a liquid that can be heated under controlled conditions using a fuel or hot gases. The shell is a drum (hereinafter “drum” or “boiler drum”) that is defined by one or more walls. Chemical energy contained in the fuel is converted into thermal energy, which heats the liquid in the boiler and causes it to vaporize. The mixture of liquid and vapor enters the drum. The walls of the drum are designed to withstand pressures exerted by the vaporized liquid. The vaporized liquid can be taken from the drum and used to provide work or as a source of heat.
- Starting a boiler that is initially at ambient conditions often causes rapid temperature changes to be experienced across the walls of the drum. These temperature changes can generate thermal stresses within the walls. Such stresses can cause crack initiation and growth in the material of the wall. In some cases, such stresses can also cause crack initiation and growth in a magnetite layer that forms on the inside of the walls of the drums that contain water.
- In both natural circulation boilers and assisted circulation boilers in which water is heated and vaporized into steam, the drum is a steam drum utilized to separate steam from the water. In boilers that operate at high pressures and/or have large drum diameters, the wall thickness is greater (as compared to boilers that operate at lower pressure and/or have small drum diameters) to maintain acceptable pressure stress levels. Increased wall thickness results in increased thermal stresses within the walls. High stresses within the walls of the drums also occur at various sites or penetrations that extend through the wall. Typical penetrations include nozzles and the like. Since the penetrations are points of weakness in the drum walls, the maximum operating pressure of the boiler is effectively restricted due to limitations imposed by the European Norm (EN) code on maximum stress ranges in boilers (and more particularly in boiler drums). The range of stress also limits the number of rapid startups that the boiler may be subjected to as well as the total number of startups over the life of the boiler.
- Thick-walled boiler drums are generally heated only on their inside surfaces, which results in temporary and uneven temperatures in the wall, particularly during the startup period. As the wall thickness increases, so does the temperature gradient through the wall. The induced thermal stress increases for a given rate of internal temperature change as the drum wall thickness increases. Over time, the wall heats up to a uniform temperature, thereby eliminating this type of thermal stress. The pressure stress then dominates. Such stresses due to thermal gradients and internal pressure, when applied and removed repeatedly, can cause crack initiation and growth in the component material. The need to limit stresses to prevent such cracks can effectively limit the rate of temperature change in the drum. By limiting the rate of temperature change, the operational flexibility (e.g., maximum pressures attainable) of the boiler is decreased. Such flexibility is desirable to provide for rapid start-ups to respond to changes in power demand.
- An additional constraint on boiler drums in compliance with EN code requirements is the limitation on stress range to avoid magnetite cracking. To avoid magnetite cracking, the difference between the highest compressive stress and the highest tensile stress should not exceed 600 mega pascals (MPa). This stress range is illustrated in
FIG. 1 , which illustrates a typical stress history for a steam drum during a boiler startup. Thermal stress that occurs early in the startup process is shown as diminishing as the temperature of the drum wall becomes more uniform as steady state operating conditions are approached. As steady state conditions are approached, the stress due to internal pressure dominates the thermal stress. For a given drum diameter, the positive hoop stress (tensile) can be reduced by increasing the drum wall thickness, but this increases the negative stress due to through wall temperatures at start up and limits the rate or number of starts. - According to aspects illustrated herein, there is provided a method of controlling stress in a boiler pressure vessel. This method comprises limiting the diameter of a drum of the boiler pressure vessel and preheating at least a portion of the wall of the drum. Limiting the diameter of the drum allows pressure in the drum to be increased for a given mechanical stress. Furthermore, preheating the wall of the drum reduces peak thermally induced stresses in a material from which the drum is fabricated.
- According to other aspects illustrated herein, there is provided a method of operating a boiler pressure vessel. This method comprises applying local heating to a portion of the boiler pressure vessel prior to a startup operation of the boiler pressure vessel, during an operation of the boiler pressure vessel, and/or during a shutdown operation of the boiler pressure vessel. In applying local heating to the boiler pressure vessel, thermally induced stresses in the boiler pressure vessel are reduced.
- According to other aspects illustrated herein, there is provided a method of controlling variables in a boiler pressure vessel. This method comprises providing a steam drum of a boiler; controlling mechanical stress in a wall of the steam drum by limiting the diameter of the steam drum; and controlling thermal stress in the wall of the steam drum by heating at least a portion of the steam drum. The heating of the portion of the steam drum is effected by preheating penetrations in the steam drum and/or an area surrounding a penetration in the steam drum during at least one of a startup period and a shutdown period of the boiler pressure vessel.
- The above described and other features are exemplified by the following Figures and Detailed Description.
- Referring now to the Figures, which are exemplary embodiments, and wherein like elements are numbered alike:
-
FIG. 1 is a graphical representation of a typical stress history for a steam drum; -
FIG. 2 is a schematic representation of a vertical section of a steam drum of a boiler; and -
FIG. 3 is a perspective view of a vertical section of a steam drum of a boiler. - Referring now to
FIG. 2 , one exemplary embodiment of a steam drum of a boiler is shown generally at 10 and is hereinafter referred to as “drum 10” or “steam drum 10.” Thedrum 10 can be from a natural circulation boiler, an assisted circulation boiler, or any other type of boiler. Thedrum 10 is of an elongated cylindrical shape and has awall 12 that is penetrated bynozzles 14 that receive a high temperature steam/liquid mixture and discharge this mixture into anannular space 16 between a drum liner orbaffle 18 and aninner surface 15 of thewall 12. Thewall 12 also has anexterior surface 17. Thenozzles 14 may extend beyond theinner surface 15 of the wall (FIG. 2 ) or they may terminate at the inner surface 15 (FIG. 3 ). Aliquid 26 such as, for example, water pools in the bottom of thedrum 10. One or moresteam separating units 24 are located outside the volume enclosed by thebaffle 18. Steam from the steam/liquid mixture 34 and from the vaporization of thewater 26 passes through adrying assembly 32 and is removed through anoutlet 30. The configuration ofFIG. 2 is not limited to that as shown, as other configurations are possible. - Upon operation of the boiler, particularly at startup from ambient conditions, the
nozzles 14 and theareas 15 a of theinner surface 15 of thewall 12 surrounding thenozzles 14 are affected by the steam/liquid mixture 34. Temperature transients (e.g., the movement of heat from one area to another) through the materials of thenozzles 14 and thewall 12 produce thermal stresses. Accordingly, thenozzles 14 and theareas 15 a surrounding the nozzles, namely, thedrum wall 12 and particularly at theinner surface 15, are subjected to stress from the high temperature steam/liquid mixture 34. Mechanical stresses such as hoop stress in thewall 12 of thedrum 10 are also encountered as the result of pressure. - Mechanical stress in the
wall 12 is a function of various process variables, namely, the radius of thedrum 10, the thickness of thewall 12, and the internal pressure of thedrum 10. This can be described by the equation: -
σm =f(PR/t) - where:
- σm is the hoop stress of the drum;
- P is the internal pressure;
- R is the drum radius; and
- t is the drum wall thickness.
- For a given internal pressure and stress, reducing the drum radius or diameter results in the thickness of the
wall 12 of thedrum 10 being reduced. - One approach to accommodating mechanical stress that is applicable to both natural circulation boilers and assisted circulation boilers with steam production greater than 50 kilogram per second (kg/s) to enable operation at higher pressures, which is desirable due to the resulting higher cycle efficiency, is to limit the thickness of the
wall 12 of thedrum 10. The thickness of thewall 12 is limited by using a relatively small diameter steam drum, for example, a steam drum having an inside diameter of between about 1,000 millimeters (mm) and about 1,775 mm. When the diameter of thedrum 10 is reduced and the thickness of thewall 12 is limited to a value that is consistent with drums having inside diameters of greater than about 1,775 mm, the value for P can be increased for a given hoop stress. Typical wall thicknesses could range from about 70 mm to about 150 mm. - Thermal stresses within the
wall 12 of thedrum 10 also occur at thenozzles 14 or other penetrations through thewall 12 to theinner surface 15 as well as at theinner surfaces 15 a proximate thenozzles 14. Referring toFIG. 3 , a localized high stress range area is shown at 20. This localized highstress range area 20 is located on theinner surface 15 proximate the area at which thenozzle 14 penetrates the wall. The stress in this localized highstress range area 20 is at least twice the stress in any other area in the rest of the drum. - It has been discovered that applying local heating to at least portions of the
drum 10 in a controlled manner can reduce the temperature transients and thermal stresses within thedrum 10. - One approach to applying local heating to accommodate thermal stress is to preheat the
nozzles 14 and thearea 15 a adjacent thereto (e.g., theinner surface area 15 a of thewall 12 in the area of the nozzle 14) prior to boiler startup when thedrum 10 is at ambient pressure conditions. In one embodiment, the local heating may be applied on theexterior surface 17 of thedrum 10 proximate the area at which thenozzle 14 enters the drum 10 (e.g.,area 17 a). This would reduce the peak thermally induced stresses in a material from which thewall 12 of thedrum 10 is fabricated that would otherwise limit the number of startups from ambient conditions or even prevent use of drum-type boilers above certain pressure ranges due to the EN code limits of stress ranges. Locally preheating of thenozzles 14 and/or thewall 12 may be used as an alternative to or in conjunction with limiting the diameter of thedrum 10. - It should also be appreciated that the approach is not limited to being undertaken at startup of the boiler, as the
nozzles 14 and thewall 12 could be heated during a shutdown operation. In doing so, the rate at which heat is dissipated from thenozzles 14 and thewall 12 would be reduced, thereby reducing the thermally induced stresses in the material of thenozzles 14 and thewall 12. - In addition to reducing thermally induced stresses by using local heating, it is contemplated that local heat uses much less energy than would be required to heat the entire drum 10 (e.g., the entire inner surface 15) and the fluid 26 that it contains, thereby reducing operational costs. Without any sort of preheating feature in place, the number of cold starts could potentially be limited to an absolute maximum in the specification (e.g., 300) as compared to an essentially unlimited number of cold starts with preheating.
- The maximum possible thermal stress for a given ramp up in temperature (temperature transient) is also a function of various process variables and varies approximately as the square of the thickness of the wall. Reduced thickness would result in reduced thermal stress for the same rate of temperature change. This is described by the equation:
-
σt =f(T r t 2) - where
- σt is the thermal stress;
- Tr is the rate of temperature change; and
- t is the drum wall thickness.
- Starting a boiler that is initially at ambient conditions results in rapid temperature changes in the
drum 10 as well is in other components of the drum 10 (e.g.,nozzles 14 and the like). These temperature changes can generate thermal stress within these components. Such stresses can cause crack initiation and growth in the material of which the component is fabricated and in some cases in a magnetite layer that forms on theinner surface 15 ofsuch drums 10 that containwater 26. Preheating at least portions of thedrum 10 or other components of the pressure vessel in a controlled manner can reduce the rate of temperature change, thereby reducing the thermal stresses within the component. Preheating thedrum 10 can be effected by electrical resistance heating or other means readily available. - Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those of skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above description, but that the invention will include all embodiments falling within the scope of the appended claims.
Claims (11)
1. A method of controlling stress in a boiler pressure vessel, the method comprising:
limiting the diameter of a drum of the boiler pressure vessel; and
preheating at least a portion of the wall of the drum;
wherein limiting the diameter of the drum allows pressure in the drum to be increased for a given mechanical stress; and
wherein preheating the wall of the drum reduces peak thermally induced stresses in a material from which the drum is fabricated.
2. The method of claim 1 , wherein limiting the diameter of the drum comprises using a drum having an inside diameter of less than about 1,775 mm.
3. The method of claim 1 , wherein preheating at least a portion of the wall of the drum comprises locally preheating penetrations in the wall of the drum.
4. The method of claim 3 , wherein locally preheating penetrations in the wall of the drum comprises heating nozzles extending into the wall of the drum.
5. The method of claim 3 , further comprising locally preheating areas of the wall of the drum adjacent to the penetrations.
6. The method of claim 1 , wherein preheating at least a portion of the wall of the drum is undertaken at at least one of a startup of the boiler pressure vessel and during an operation of the boiler pressure vessel.
7. The method of claim 1 , wherein preheating at least a portion of the wall of the drum is undertaken during a shutdown of the boiler pressure vessel.
8. A method of operating a boiler pressure vessel, the method comprising:
applying local heating to a portion of the boiler pressure vessel during at least one of prior to a startup operation of the boiler pressure vessel, during an operation of the boiler pressure vessel, and during a shutdown operation of the boiler pressure vessel;
wherein applying local heating to the boiler pressure vessel reduces thermally induced stresses in the boiler pressure vessel.
9. The method of claim 8 , wherein applying local heating to the portion of the wall of the boiler pressure vessel comprises at least one of,
heating a penetration extending into a surface of a drum of the boiler pressure vessel; and
heating an area surrounding the penetration extending into the surface of the drum.
10. The method of claim 8 , further comprising limiting a diameter of a drum of the boiler pressure vessel, wherein limiting the diameter of the drum reduces mechanical stresses in the boiler pressure vessel.
11. A method of controlling variables in a boiler pressure vessel, the method comprising:
providing a steam drum of a boiler;
controlling mechanical stress in a wall of the steam drum by limiting the diameter of the steam drum; and
controlling thermal stress in the wall of the steam drum by heating at least a portion of the steam drum; and
wherein the heating of the portion of the steam drum is effected by preheating at least one of penetrations in the steam drum and an area surrounding a penetration in the steam drum during at least one of a startup period and a shutdown period of the boiler pressure vessel.
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/690,197 US20110174240A1 (en) | 2010-01-20 | 2010-01-20 | Controlling variables in boiler pressure vessels |
CN2010800656186A CN102859276A (en) | 2010-01-20 | 2010-12-08 | Controlling variables in boiler pressure vessels |
EP10795843.1A EP2526338B1 (en) | 2010-01-20 | 2010-12-08 | Method of operating a boiler vessel |
PCT/US2010/059389 WO2011090576A2 (en) | 2010-01-20 | 2010-12-08 | Controlling variables in boiler pressure vessels |
MX2012008402A MX2012008402A (en) | 2010-01-20 | 2010-12-08 | Controlling variables in boiler pressure vessels. |
CN201810606868.4A CN109028009A (en) | 2010-01-20 | 2010-12-08 | Control the variable in boiler pressure vessel |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/690,197 US20110174240A1 (en) | 2010-01-20 | 2010-01-20 | Controlling variables in boiler pressure vessels |
Publications (1)
Publication Number | Publication Date |
---|---|
US20110174240A1 true US20110174240A1 (en) | 2011-07-21 |
Family
ID=44276604
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/690,197 Abandoned US20110174240A1 (en) | 2010-01-20 | 2010-01-20 | Controlling variables in boiler pressure vessels |
Country Status (5)
Country | Link |
---|---|
US (1) | US20110174240A1 (en) |
EP (1) | EP2526338B1 (en) |
CN (2) | CN109028009A (en) |
MX (1) | MX2012008402A (en) |
WO (1) | WO2011090576A2 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130152587A1 (en) * | 2011-12-14 | 2013-06-20 | General Electric Company | System and method for warming up a steam turbine |
WO2016192887A1 (en) * | 2015-06-02 | 2016-12-08 | Siemens Aktiengesellschaft | Method for making a flow guiding unit cool down more slowly, and flow conducting unit |
CN111219703A (en) * | 2020-01-20 | 2020-06-02 | 广东韶钢松山股份有限公司 | Boiler drum and method for reforming boiler drum based on reverse simulation analysis |
Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2271652A (en) * | 1939-07-01 | 1942-02-03 | Babcock & Wilcox Co | Welded pressure vessel |
US2743709A (en) * | 1952-04-12 | 1956-05-01 | Combustion Eng | Equalizing the temperature of high pressure boiler drum walls |
US3117560A (en) * | 1962-01-10 | 1964-01-14 | Riley Stoker Corp | Steam generating unit |
US3516391A (en) * | 1968-06-20 | 1970-06-23 | Riley Stoker Corp | Steam generating unit |
US3765572A (en) * | 1970-09-18 | 1973-10-16 | Concast Ag | Rotatable tundish with multiple outlets |
US3789806A (en) * | 1971-12-27 | 1974-02-05 | Foster Wheeler Corp | Furnace circuit for variable pressure once-through generator |
US5061304A (en) * | 1981-03-27 | 1991-10-29 | Foster Wheeler Energy Corporation | Steam processing apparatus and method |
US20030005769A1 (en) * | 2001-07-03 | 2003-01-09 | Alstom Power N.V. | Apparatus for continuously monitoring liquid level conditions in a liquid-vapor separating device |
US20030011113A1 (en) * | 2001-07-13 | 2003-01-16 | Heraeus Electro-Nite International N.V. | Refractory nozzle |
US20050087151A1 (en) * | 2003-10-23 | 2005-04-28 | Nem B.V. | Evaporator system |
US20060197638A1 (en) * | 2005-01-31 | 2006-09-07 | Shiro Takahashi | Induction heating stress improvement |
US7727389B1 (en) * | 2009-09-18 | 2010-06-01 | Green Intectuac Properties | System for removing hydrocarbons and contaminates |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB710185A (en) * | 1950-04-22 | 1954-06-09 | Comb Engineering Superheating | Improvements in or relating to steam boilers, and more particularly to steam and water drums therefor |
CN2034676U (en) * | 1988-02-27 | 1989-03-22 | 国营风华机器厂 | Waste heat recovery installation of bridge type doubk flow passage heating pipe |
DE602004024705D1 (en) * | 2004-12-29 | 2010-01-28 | Son S R L | steam generator |
WO2008154599A1 (en) * | 2007-06-11 | 2008-12-18 | Brightsource Energy, Inc. | Solar receiver |
-
2010
- 2010-01-20 US US12/690,197 patent/US20110174240A1/en not_active Abandoned
- 2010-12-08 CN CN201810606868.4A patent/CN109028009A/en active Pending
- 2010-12-08 WO PCT/US2010/059389 patent/WO2011090576A2/en active Application Filing
- 2010-12-08 MX MX2012008402A patent/MX2012008402A/en unknown
- 2010-12-08 CN CN2010800656186A patent/CN102859276A/en active Pending
- 2010-12-08 EP EP10795843.1A patent/EP2526338B1/en active Active
Patent Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2271652A (en) * | 1939-07-01 | 1942-02-03 | Babcock & Wilcox Co | Welded pressure vessel |
US2743709A (en) * | 1952-04-12 | 1956-05-01 | Combustion Eng | Equalizing the temperature of high pressure boiler drum walls |
US3117560A (en) * | 1962-01-10 | 1964-01-14 | Riley Stoker Corp | Steam generating unit |
US3516391A (en) * | 1968-06-20 | 1970-06-23 | Riley Stoker Corp | Steam generating unit |
US3765572A (en) * | 1970-09-18 | 1973-10-16 | Concast Ag | Rotatable tundish with multiple outlets |
US3789806A (en) * | 1971-12-27 | 1974-02-05 | Foster Wheeler Corp | Furnace circuit for variable pressure once-through generator |
US5061304A (en) * | 1981-03-27 | 1991-10-29 | Foster Wheeler Energy Corporation | Steam processing apparatus and method |
US20030005769A1 (en) * | 2001-07-03 | 2003-01-09 | Alstom Power N.V. | Apparatus for continuously monitoring liquid level conditions in a liquid-vapor separating device |
US20030011113A1 (en) * | 2001-07-13 | 2003-01-16 | Heraeus Electro-Nite International N.V. | Refractory nozzle |
US20050087151A1 (en) * | 2003-10-23 | 2005-04-28 | Nem B.V. | Evaporator system |
US20060197638A1 (en) * | 2005-01-31 | 2006-09-07 | Shiro Takahashi | Induction heating stress improvement |
US7727389B1 (en) * | 2009-09-18 | 2010-06-01 | Green Intectuac Properties | System for removing hydrocarbons and contaminates |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130152587A1 (en) * | 2011-12-14 | 2013-06-20 | General Electric Company | System and method for warming up a steam turbine |
US9903231B2 (en) * | 2011-12-14 | 2018-02-27 | General Electric Company | System and method for warming up a steam turbine |
WO2016192887A1 (en) * | 2015-06-02 | 2016-12-08 | Siemens Aktiengesellschaft | Method for making a flow guiding unit cool down more slowly, and flow conducting unit |
CN107683365A (en) * | 2015-06-02 | 2018-02-09 | 西门子公司 | For the method and flowing guidance unit of the cooling for slowing down flowing guidance unit |
CN111219703A (en) * | 2020-01-20 | 2020-06-02 | 广东韶钢松山股份有限公司 | Boiler drum and method for reforming boiler drum based on reverse simulation analysis |
Also Published As
Publication number | Publication date |
---|---|
CN109028009A (en) | 2018-12-18 |
EP2526338A2 (en) | 2012-11-28 |
WO2011090576A3 (en) | 2012-07-05 |
WO2011090576A2 (en) | 2011-07-28 |
EP2526338B1 (en) | 2017-01-11 |
MX2012008402A (en) | 2012-10-09 |
CN102859276A (en) | 2013-01-02 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR100827468B1 (en) | Electric boiler using high frequency induction heaing | |
EP1779035B1 (en) | Once-through boiler | |
US20110174240A1 (en) | Controlling variables in boiler pressure vessels | |
JP6046706B2 (en) | Evaporative gas generator, evaporative gas production method, hydrogen bromide production apparatus, and hydrogen bromide production method | |
JP6924042B2 (en) | Systems and methods for heating components of waste heat recovery steam generators | |
JP2009236039A (en) | Steam valve device and steam turbine plant equipped with the same | |
KR101685235B1 (en) | A pressurizer with a mechanically attached surge nozzle thermal sleeve | |
US8955467B1 (en) | Steam boiler | |
CN107726619A (en) | A kind of method for the heating plant hot-water supply and/or steam for exporting deep fat | |
EP3025110B1 (en) | System and method for recovering waste heat generated in internally insulated reactors | |
Kantor | Modelling of a coupled radiation-conduction heat transfer through a heat shield in vacuum thermal isolation applications | |
US20090141850A1 (en) | Pressurized water reactor pressurizer heater sheath | |
US10005244B2 (en) | Manufacturing method of pressure vessel with heating device | |
US11298672B2 (en) | Reactor heating to achieve minimum pressurization temperature | |
JP2015175506A (en) | Piping coating structure | |
KR20200023724A (en) | Hot water and steam boiler | |
JPH11300547A (en) | Turbine casing bolt fastening device | |
JP2008189983A (en) | Method for reducing residual stress in small diameter piping | |
JP6395458B2 (en) | Piping protection device, piping protection method, and nuclear facility | |
JP2005160918A (en) | Rice cooker | |
EP2505677A2 (en) | Method and apparatus for relieving stress in a pipeline | |
RU2575518C2 (en) | Control over variable temperatures of drum | |
KR101355514B1 (en) | Method for controlilng temperature of drum water in boiler using surplus steam | |
US20170121607A1 (en) | Design of an air injection system at the level of the cylinder in a coke drum | |
JP2012097863A (en) | Method and device for suppressing crack extension in pipe |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ALSTOM TECHNOLOGY LTD., SWITZERLAND Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BAIRLEY, DONALD W.;BAUVER, WESLEY P., II;DROUX, FRANCOIS;AND OTHERS;SIGNING DATES FROM 20100224 TO 20100308;REEL/FRAME:024098/0195 |
|
AS | Assignment |
Owner name: GENERAL ELECTRIC TECHNOLOGY GMBH, SWITZERLAND Free format text: CHANGE OF NAME;ASSIGNOR:ALSTOM TECHNOLOGY LTD;REEL/FRAME:039714/0578 Effective date: 20151102 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |