Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
  • F23J15/00—Arrangements of devices for treating smoke or fumes
  • F23J15/06—Arrangements of devices for treating smoke or fumes of coolers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F22—STEAM GENERATION
  • F22D—PREHEATING, OR ACCUMULATING PREHEATED, FEED-WATER FOR STEAM GENERATION; FEED-WATER SUPPLY FOR STEAM GENERATION; CONTROLLING WATER LEVEL FOR STEAM GENERATION; AUXILIARY DEVICES FOR PROMOTING WATER CIRCULATION WITHIN STEAM BOILERS
  • F22D1/00—Feed-water heaters, i.e. economisers or like preheaters
  • F22D1/36—Water and air preheating systems
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23L—SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
  • F23L15/00—Heating of air supplied for combustion
  • F23L15/04—Arrangements of recuperators
• • 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
  • F28D19/00—Regenerative heat-exchange apparatus in which the intermediate heat-transfer medium or body is moved successively into contact with each heat-exchange medium
  • F28D19/04—Regenerative heat-exchange apparatus in which the intermediate heat-transfer medium or body is moved successively into contact with each heat-exchange medium using rigid bodies, e.g. mounted on a movable carrier
  • F28D19/041—Regenerative heat-exchange apparatus in which the intermediate heat-transfer medium or body is moved successively into contact with each heat-exchange medium using rigid bodies, e.g. mounted on a movable carrier with axial flow through the intermediate heat-transfer medium
  • F28D19/042—Rotors; Assemblies of heat absorbing masses
• • 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
  • F28D19/00—Regenerative heat-exchange apparatus in which the intermediate heat-transfer medium or body is moved successively into contact with each heat-exchange medium
  • F28D19/04—Regenerative heat-exchange apparatus in which the intermediate heat-transfer medium or body is moved successively into contact with each heat-exchange medium using rigid bodies, e.g. mounted on a movable carrier
  • F28D19/047—Sealing means
• • 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
  • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
  • F23J2219/00—Treatment devices
  • F23J2219/80—Quenching
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23L—SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
  • F23L2900/00—Special arrangements for supplying or treating air or oxidant for combustion; Injecting inert gas, water or steam into the combustion chamber
  • F23L2900/15043—Preheating combustion air by heat recovery means located in the chimney, e.g. for home heating devices
• • 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
  • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
  • F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E20/00—Combustion technologies with mitigation potential
  • Y02E20/34—Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery

Definitions

• the present invention is directed to a system for efficiently capturing wasted heat from a flue gas output of a boiler. More particularly, the present invention is directed to a system for capturing wasted heat from a flue gas output of a boiler to preheat the feed water to the boiler.
• EPHRS exhaust processing and heat recovery
• FIG. 1 shows a power generation system 10 that includes a steam generation system 25 and an exhaust processing and heat recovery system (EPHRS) 15 and an exhaust stack 90.
• the steam generation system 25 includes a boiler 26.
• the EPRS 15 includes an air preheater 50, a particulate removal system 70 and a flue gas scrubber system, shown here as a wet scrubber system 80.
• the particulate removal system 70 may be, for example, an electrostatic precipitator (ESP), a fabric filter system (Bag House) or the like.
• ESP electrostatic precipitator
• FD forced draft
• the air preheater 50 is a device designed to heat air before it is introduced to another process such as, for example, combustion in the combustion chamber of a boiler 26.
• the air preheater heats the air stream input A2 to the boiler 26 capturing/recovering heat expelled from the boiler 26 via the flue gas stream from the boiler.
• economizer section 55 is a type of heat exchanger used to capture heat from an air stream and transfer the heat into a fluid stream, such as, for example, water. Further, economizers are typically designed with finned tubes that improve the transfer of heat. In boilers, economizers are heat exchange devices that heat fluids, usually water, up to but not normally beyond the boiling point of that fluid.
• Economizers are so named because they can make use of the enthalpy in fluid streams that are hot, but not hot enough to be used in a boiler, thereby recovering more useful enthalpy and improving the boiler's efficiency.
• the economizer is a device that is coupled to boiler 26 which saves energy by using the exhaust flue gases FG from the boiler 26 to preheat/heat the feed water WF from a water supply 65.
• FIG. 1 it shows that economizer 150 is configured to receive the flue gas stream FG from the boiler 26, and to pass the flue gas stream FG1 on to the air preheater 50.
• the economizer 55 acts to transfer heat from the flue gas stream FG to feed water WF that is provided to the boiler 25. This allows "pre-heated” water to be introduced into the boiler 25, thereby reducing the need for additional heat energy to heat the boiler water to a desired temperature.
• the flue gas stream FG/FG1 will generally contain a substantial level of particulate matter.
• This particulate matter is typically removed from the flue gas stream after the flue gas stream FG2 has passed through the particulate removal system 70. However, until the flue gas stream is subjected to particulate removal operations, the presence of particulate matter in the flue gas stream is typically high. Since the economizer 55 receives the flue gas stream prior to it being subjected to dust removal operations, it is possible for particulate matter to get caught in between the heat exchange elements of the economizer 55 if the spacing between the heat exchange elements is not sufficient.
• the present invention may be embodied as an economical heat recovery system [100] for use with a boiler [26] that boils water feed from a water supply [125] supplied to it.
• RHCT regenerative heat capture and transfer
• the RHCT uses a heat exchanger [310] to receive the incremental air stream [A2 1 ] from the air preheater, receive the water feed [WF1] and transfer heat from the incremental air [A2 1 ] to water feed [WF1] to create preheated water feed [WF2].
• a pump 330 coupled to said water supply [125] and to the heat exchanger [310] pumps the feed water [WF1] from water supply [125] through the heat exchanger [310] and the preheated water feed [Wf2] to the boiler [26].
• FIG. 1 is a block diagram depicting a portion of a power generation system 10 according to the prior art.
• FIG. 2 is a simplified block diagram depicting an embodiment of a power generation system 100 according to the present invention that incorporates a regenerative heat capture and transfer system (RHCT) 300.
• RHCT regenerative heat capture and transfer system
• FIG. 3 is a simplified block diagram depicting another embodiment of a power generation system 100 that incorporates a RHCT system 300 according to the present invention.
• FIG. 4 is an enlarged block diagram depicting an embodiment of the RHCT system 300 of FIGs. 2 and 3.
• FIG. 5 is a simplified block diagram depicting another embodiment of a power generation system 100 that incorporates a RHCT system 300 according to the present invention.
• FIG. 6 is an enlarged block schematic diagram depicting the capture of heated leakage air from a rotary air preheater.
• FIG. 2 is a simplified block diagram depicting an embodiment of a power generation system 100 according to the present invention that incorporates a regenerative heat capture and transfer system (RHCT) 300.
• a power generation system 100 is provided that includes a steam generation system 25, an exhaust processing and heat recovery system (EPHRS) 15, a regenerative heat capture and transfer system (RHCT) 300, a water supply 125 and an exhaust stack 90.
• EPHRS exhaust processing and heat recovery system
• RHCT regenerative heat capture and transfer system
• Steam generation system 25 includes a boiler 26.
• the EPRS 15 includes a regenerative air preheater 50, a particulate removal system 70 and a wet scrubber system 80.
• a forced draft (FD) fan 60 is provided to introduce an air stream A1 into the cold side input of the air preheater 50.
• air preheater 50 heats the air stream A1 and outputs it as a heated air stream A2 that is fed to an air intake of the combustion chamber (not shown) of boiler 26 for combustion.
• FD forced draft
• Exhaust gases FG1 expelled from the combustion chamber (not shown) of boiler 26 are received by a hot side input of the air preheater 50. These exhaust gases FG1 are cooled via the air preheater 50 and output as a cooler temperature exhaust gas stream FG2. Previously, gasses leaving air preheater 150 had to remain hot enough to prevent condensation of compounds in the flue gas. This reduced corrosion of the equipment downstream from the preheater 50.
• Exhaust gas stream FG2 is then processed to remove particulate matter via particulate removal system 70.
• the particulate removal system 70 may be, for example, an electrostatic precipitator (ESP), a fabric filter system (Bag House) or the like.
• the processed exhaust stream FG3 may be further processed via, for example, a wet scrubber 80 to remove, for example, sulfuric oxide (SO2).
• This processed stream FG4 is then output for introduction to the exhaust stack 90.
• Regenerative heat capture and transfer system (RHCT) 300 is configured to receive an air stream A2' and extract thermal energy therefrom.
• Air stream A2' is a portion of air stream A2 expelled from the air preheater 50.
• the thermal energy extracted from air stream A2' is transferred to a water feed supply WF1 which is then output as heated water feed WF2 and introduced to boiler 26.
• RHCT 300 is configured and positioned so as to transfer thermal energy from the input air stream A2' to water feed WF1 without receiving contaminates.
• Air streams A2/A2' are clean air stream that do not mix with the flue gas streams that have significant amount of particulate matter. Further, since no flue gas is used by the RHCT 300 to heat the water feed supply WF1 , the RCHT 300 is not subjected to particulate matter that is often found in the flue gas stream FG.
• Air preheater 150 can now be designed to be a high efficiency air preheater transferring a greater amount of heat. Also, air preheater 150 may be designed to output a greater volume of heated air than can be efficiently put to use by the steam generation system 25, creating excess heated air.
• FIG. 3 is a simplified block diagram depicting another embodiment of a power generation system 100 that incorporates a RHCT system 300 according to the present invention.
• air preheater 150 has one flue gas duct and two heated input air ducts. The output of one heated air duct releases heated air stream A2. This is provided to boiler 26. The second heated air duct provides incremental air stream A2' that is passed to RHCT 300.
• FIG. 3 perform the same function as the parts of other figures having the same reference number.
• FIG. 4 is an enlarged block diagram depicting an embodiment of the RHCT system 300 of FIGs. 2 and 3.
• the RHCT 300 includes heat exchanger 310 and pump 330.
• Heat exchanger 310 is preferably configured to receive a portion A2' of the heated air stream A2 from the air preheater 150.
• the RCHT 300 is not subjected to the particulate matter typically found in the flue gas stream FG, it is possible for the heat exchange elements (not shown) used in the economizer to be placed in much closer proximity to each other and thereby provide for more surface area available to contact the air stream A2/A2'. In this way, the efficiency of the heat exchanger 310 can be significantly enhanced since the greater the surface area of the heat exchange elements that is provide, the more heat that can be captured for a given volume. Further, since the heat exchange elements are not subjected to much particulate matter, the threat of blockage due to accumulations of particulate matter in the economizer is greatly reduced, if not completely avoided.
• the finned tubes will not be exposed to coal ash (only preheated air); therefore, the fin density spacing can be reduced significantly from that of a typical economizer tube designed for exposure to flyash.
• the size of the economizer should be more efficient and smaller.
• FIG. 5 is a block diagram depicting another embodiment of a power generation system 100 that incorporates a RHCT system 300 according to the present invention.
• FIG. 6 is an enlarged block schematic diagram depicting the capture of heated leakage gasses 360 from a rotary air preheater 150.
• Hot flue gasses FG 1 are passed into a hot side of an air preheater 150.
• a wheel 151 rotates on an axle 152.
• a motor causes rotation of wheel 151.
• Wheel 151 has a plurality of air conduits passing through the wheel. Each of these has heating elements that heat us as flue gas FG1 passes through the conduits. These heating elements rotate to the cool side of the wheel where inlet air A1 is received. The inlet air comes in contact with the hot heating elements and is heated into preheated air A2 that exits the air preheater 150. Heating element cool as the input air A1 passes over them.
• Wheel 151 continues to rotate and the heating elements come in contact with hot flue gasses FG1 again, absorbing heat. This process then continues.
• outer seals 157, 158 that stop most of the leakage of hot flue gasses past the outer edge of wheel 151.
• inner seals that stop most of the flue gas leakage toward the inner hub section of wheel 151. However, some flue gas leaks past the seals and into inner plenums between the wheel and housing 154.
• a leakage outlet 325 is provided. This outlet may be implemented as an opening in the housing 154, which allows access to the plenum 159.
• An exhaust conduit 361 is provided for exhausting gas/air that may accumulate in the internal plenum 159.
• a fan device 367 may be provided to allow leakage gasses 360 to be exhausted from the internal plenum 159 more easily.
• a further leakage outlet may also be provided so that leakage gases accumulating within the internal plenum 365 may be readily exhausted through another exhaust conduit 361.
• Fan 367 also draws the leakage gasses 360 from exhaust conduit 363.
• the leakage gasses 360 and/or incremental air stream [A2'] are provided to the RHCT 300 to further heat the feed water [WF1]. Use of this wasted heat increases the efficiency of the boiler.
• a separate fan may be employed for each exhaust conduit if so desired.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Air Supply (AREA)
• Chimneys And Flues (AREA)

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• 2009
  • 2009-04-01 US US12/416,498 patent/US20100251975A1/en not_active Abandoned
• 2010
  • 2010-02-12 EP EP10704704A patent/EP2414735A1/en not_active Withdrawn
  • 2010-02-12 WO PCT/US2010/024016 patent/WO2010114647A1/en active Application Filing
  • 2010-02-12 JP JP2012503445A patent/JP2012522961A/ja active Pending
  • 2010-02-12 KR KR1020117025618A patent/KR20120003002A/ko active IP Right Grant
  • 2010-02-12 MX MX2011010426A patent/MX2011010426A/es unknown
  • 2010-02-12 CN CN2010800152343A patent/CN102378879A/zh active Pending
  • 2010-02-12 CA CA2757021A patent/CA2757021A1/en not_active Abandoned
  • 2010-03-31 TW TW099109943A patent/TW201043877A/zh unknown

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