US20130269345A1 - Retrofit for power generation system - Google Patents
Retrofit for power generation system Download PDFInfo
- Publication number
- US20130269345A1 US20130269345A1 US13/448,909 US201213448909A US2013269345A1 US 20130269345 A1 US20130269345 A1 US 20130269345A1 US 201213448909 A US201213448909 A US 201213448909A US 2013269345 A1 US2013269345 A1 US 2013269345A1
- Authority
- US
- United States
- Prior art keywords
- turbine
- combustor
- working fluid
- retrofit
- cycle
- 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
- 238000010248 power generation Methods 0.000 title claims abstract description 23
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims abstract description 76
- 229910002092 carbon dioxide Inorganic materials 0.000 claims abstract description 38
- 239000001569 carbon dioxide Substances 0.000 claims abstract description 38
- 238000004891 communication Methods 0.000 claims abstract description 14
- 238000000034 method Methods 0.000 claims abstract 15
- 238000009420 retrofitting Methods 0.000 claims abstract 3
- 239000012530 fluid Substances 0.000 claims description 59
- 229910000601 superalloy Inorganic materials 0.000 claims description 13
- 239000000463 material Substances 0.000 claims description 10
- 229910000831 Steel Inorganic materials 0.000 claims description 9
- 239000010959 steel Substances 0.000 claims description 9
- 238000012986 modification Methods 0.000 claims description 2
- 230000004048 modification Effects 0.000 claims description 2
- 238000011144 upstream manufacturing Methods 0.000 claims 2
- 230000008878 coupling Effects 0.000 claims 1
- 238000010168 coupling process Methods 0.000 claims 1
- 238000005859 coupling reaction Methods 0.000 claims 1
- 230000005611 electricity Effects 0.000 description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- 239000003245 coal Substances 0.000 description 5
- 238000002485 combustion reaction Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 239000003463 adsorbent Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 235000019738 Limestone Nutrition 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- UGKDIUIOSMUOAW-UHFFFAOYSA-N iron nickel Chemical compound [Fe].[Ni] UGKDIUIOSMUOAW-UHFFFAOYSA-N 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
Images
Classifications
-
- 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
- F01K25/00—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for
- F01K25/08—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours
- F01K25/10—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours the vapours being cold, e.g. ammonia, carbon dioxide, ether
- F01K25/103—Carbon dioxide
-
- 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
- F01K23/00—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids
- F01K23/02—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled
- F01K23/06—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled combustion heat from one cycle heating the fluid in another cycle
- F01K23/10—Plants characterised by more than one engine delivering power external to the plant, the engines being driven by different fluids the engine cycles being thermally coupled combustion heat from one cycle heating the fluid in another cycle with exhaust fluid of one cycle heating the fluid in another cycle
Definitions
- This disclosure relates to power plants for generating electricity.
- FIG. 1 is a schematic view of a pre-existing power generation system.
- FIG. 2 is a schematic view of a retrofit power generation system based upon the pre-existing power generation system of FIG. 1 .
- FIG. 3 is a schematic view of another example retrofit power generation system based upon the pre-existing power generation system of FIG. 1 .
- FIG. 4 is a schematic view of another example pre-existing power generation system.
- FIG. 5 is a schematic view of a retrofit power generation system based upon the pre-existing power generation system of FIG. 4 .
- FIG. 1 shows a schematic view of selected portions of a pre-existing power generation system 20 (“system 20 ”).
- system 20 generally refers to the system 20 having been in operation for its intended use for some period of time.
- the system 20 can be retrofitted with new, more efficient hardware, while retaining at least some of the pre-existing hardware of the system 20 , to produce more power per unit of coal or fuel input.
- a retrofit system as disclosed herein is expected to achieve 5-10% increase in overall net thermal efficiency, 10-30% lower carbon dioxide emissions, up to 25% reduction in levelized cost of energy and the ability to meet proposed regulations with regard to efficiency and emissions per unit of electricity produced.
- the system 20 includes a combustor 22 , such as a coal-fired boiler, which receives an input coal feed 24 a and an input oxidant feed 24 b (e.g., air) that generate heat within the combustor 22 .
- a steam-based cycle 26 (power cycle) absorbs heat from the combustor 22 to generate electricity.
- the steam-based cycle 26 includes a first turbine 28 , a second turbine 30 and third turbine 32 .
- the turbines 28 / 30 / 32 are mounted on a shaft 34 , which is coupled to drive a generator 36 .
- the third turbine 32 is in communication with a condenser 38 , which is connected in circuit to the combustor 22 .
- the combustor 22 , turbines 28 / 30 / 32 and condenser 38 are connected within a closed loop, working fluid circuit 40 .
- the working fluid circuit 40 includes steel tubes that convey water, steam or both between the combustor 22 , turbines 28 / 30 / 32 and condenser 38 , as generally indicated by the arrows in the working fluid circuit 40 .
- liquid water is discharged from the condenser 38 into the combustor 22 .
- the combustor 22 generally operates in a temperature regime of less than 700° F./371° C. and pressure of less than 3000 pounds per square inch/20.5 megapascals due to the limits of the materials of the working fluid circuit 40 and the turbines 28 / 30 / 32 .
- the water absorbs heat within the combustor 22 and turns to steam.
- the steam is then expanded over the first turbine 28 .
- the expanded steam from the first turbine 28 is circulated back through the combustor 22 for a reheat.
- the reheated steam is then expanded over the second turbine 30 and then the third turbine 32 .
- the expanded steam from the third turbine 32 is condensed in the condenser 38 prior to circulation into the combustor 22 for another thermodynamic cycle.
- the system 20 utilizes relatively inefficient technology.
- the tubes of the working fluid circuit 40 and components of the turbines 28 / 30 / 32 are made of steel.
- the working fluid circuit 40 and turbines 28 / 30 / 32 have a maximum operating temperature to which the materials of these components can be exposed.
- the temperature in the combustor 22 is controlled using a water quench or the like to ensure that actual operating temperatures of the steam do not exceed the maximum operating temperature limit of the materials of the working fluid circuit 40 and the turbines 28 / 30 / 32 .
- the operating efficiency of the system 20 is limited by the maximum allowed temperature in the combustor 22 and steam-based cycle 26 .
- the system 20 as-is has only limited ability to improve carbon dioxide emissions per unit of generated electricity and levelized cost of energy.
- the system 20 of FIG. 1 has been retrofitted with efficiency enhancements to produce a retrofitted power generation system 20 ′ (retrofit system 20 ′).
- retrofit or variations thereof may be used to refer to an individual hardware component or to a system, for example. When used with reference to an individual hardware component for use in a system, the term indicates that the component was not part of the operable initial or prior system and is not a mere replacement in kind of a like component of the operable initial or prior system.
- the term indicates that the system includes at least some pre-existing hardware components and at least one added hardware component that was not part of the operable initial or prior system and is not a mere replacement in kind of a like component of the operable initial or prior system.
- the modifying terms “pre-existing” and “retrofit” as used herein thus indicate a physical distinction between components and/or systems.
- the retrofit system 20 ′ utilizes a portion of the pre-existing hardware of the system 20 , including the pre-existing combustor 22 , the pre-existing turbines 28 / 30 / 32 and the pre-existing condenser 38 .
- the working fluid circuit 40 is replaced with a second (retrofit) working fluid circuit 50 that is directly coupled through the combustor 22 and the retrofit system 20 ′ includes at least one additional, retrofit turbine 52 mounted on the shaft 34 . Although only one retrofit turbine 52 is shown, it is to be understood that additional retrofit turbines 52 could be used.
- the retrofit turbine 52 , the combustor 22 , the turbines 28 / 30 / 32 and condenser 38 are connected within the second working fluid circuit 50 .
- the second working fluid circuit 50 includes superalloy tubes that convey water, steam or both between the combustor 22 , retrofit turbine 52 , turbines 28 / 30 / 32 and the condenser 38 , as generally indicated by the arrows in the second working fluid circuit 50 .
- a “superalloy” as used herein refers to a nickel-based, cobalt-based or nickel-iron-based alloy.
- liquid water is discharged from the condenser 38 into the combustor 22 .
- the water absorbs heat within the combustor 22 and turns to steam.
- the steam is then expanded over the retrofit turbine 52 .
- the expanded steam from the retrofit turbine 52 is then serially expanded over the first turbine 28 , the second turbine 30 and the third turbine 32 .
- the expanded steam from the third turbine 32 is then condensed in the condenser 38 prior to being circulated to the combustor 22 for another thermodynamic cycle.
- the retrofit system 20 ′ has enhanced efficiency in comparison with the system 20 with regard to carbon dioxide emissions per unit of electricity generated.
- the tubes of the second working fluid circuit 50 and components of the retrofit turbine 52 are made of superalloy materials.
- the second working fluid circuit 50 and retrofit turbine 52 have a second maximum operating temperature that is greater than the maximum operating temperature of the prior working fluid circuit 40 and turbines 28 / 30 / 32 that include steel or other lower melting point materials.
- the second working fluid circuit 50 can thus be routed through a hotter portion 22 a of the combustor 22 than the prior working fluid circuit 40 , or the combustor 22 can be operated at a higher temperature to generate higher temperature steam.
- the combustor 22 operates in a temperature regime of up to 1300° F./705° C. and pressure of up to 6000 pounds per square inch/41 megapascals.
- the steam cools to a temperature that is within the maximum operating temperature of the turbines 28 / 30 / 32 .
- the retrofit system 20 ′ can be operated at higher, more efficient temperatures to improve carbon dioxide emissions per unit of generated electricity and to reduce levelized cost of energy.
- the system 20 of FIG. 1 is retrofitted with efficiency enhancements to produce a retrofitted power generation system 20 ′′ (retrofit system 20 ′′).
- the system 20 has been retrofitted with a super-critical carbon dioxide-based Brayton cycle 54 to enhance efficiency.
- the retrofit system 20 ′′ utilizes a portion of the pre-existing hardware of the system 20 , including the pre-existing combustor 22 , pre-existing turbine 32 and pre-existing condenser 38 ,
- the working fluid circuit 40 is replaced with a second (retrofit) working fluid circuit 50 ′ that extends through the combustor 22 .
- the retrofit system 20 ′′ also includes at least one additional, retrofit turbine 52 ′ mounted on the shaft 34 .
- the super-critical carbon dioxide-based Brayton cycle 54 is thermally coupled through the combustor 22 and the prior steam-based cycle 26 is converted to a steam-based Rankine cycle 26 ′ that is in thermal-receiving communication with the super-critical carbon dioxide-based Brayton cycle 54 .
- the prior steel tubes of the working fluid circuit 40 are removed, including removal from the combustor 22 .
- Superalloy tubes of the second working fluid circuit 50 ′ are added and are directly coupled through the combustor 22 .
- the addition of the super-critical carbon dioxide-based Brayton cycle 54 includes adding a retrofit compressor 56 , a retrofit first turbine 58 and a retrofit second turbine 60 .
- the prior steam-based cycle 26 is modified to add a retrofit heat exchanger 62 for thermal communication between the super-critical carbon dioxide-based Brayton cycle 54 and the steam-based Rankine cycle 26 ′.
- the retrofit compressor 56 , the retrofit first turbine 58 , the retrofit second turbine 60 and the pre-existing turbine 32 are mounted on the common shaft 34 to drive the generator 36 .
- the retrofit first turbine 58 and the retrofit second turbine 60 each includes a rotor having a disk 66 and a plurality of blades 68 mounted on the disk 66 .
- a working fluid such as carbon dioxide or a carbon dioxide-containing mixture (e.g., with helium) in the second working fluid circuit 50 ′ absorbs heat within the combustor 22 and is then expanded over the retrofit first turbine 58 .
- the expanded working fluid is then circulated back into the combustor 22 for a reheat.
- the reheated working fluid is then expanded over the retrofit second turbine 60 and then circulated to the retrofit heat exchanger 62 .
- the working fluid in the retrofit heat exchanger 62 heats water within the steam-based Rankine cycle 26 ′.
- the working fluid is then pressurized in the retrofit compressor 56 prior to circulating to the combustor 22 for another thermodynamic cycle.
- the heated steam from the heat exchanger 62 expands over the pre-existing turbine 32 and then circulates to the condenser 38 for another thermodynamic cycle.
- the retrofit system 20 ′′ has enhanced efficiency in comparison with the system 20 with regard to carbon dioxide emissions per unit of electricity generated.
- the tubes of the second working fluid circuit 50 ′ and the disks 66 and blades 68 of the retrofit turbines 58 / 60 are made of superalloy materials.
- the second working fluid circuit 50 ′ and retrofit turbines 58 / 60 have a second maximum operating temperature that is greater than the maximum operating temperature of the prior working fluid circuit 40 and turbines 28 / 30 / 32 that include steel materials.
- the second working fluid circuit 50 ′ can thus be routed through a hotter portion 22 a of the combustor 22 than the prior working fluid circuit 40 , or the combustor 22 can be operated at a higher temperature to generate higher temperature working fluid.
- the combustor 22 operates in a temperature regime of up to 1300° F./705° C. and pressure of up to 6000 pounds per square inch/41 megapascals.
- the retrofit system 20 ′′ can be operated at higher, more efficient temperatures to improve carbon dioxide emissions per unit of generated electricity and to reduce levelized cost of energy.
- FIG. 4 illustrates another example pre-existing power generation system 120 .
- the pre-existing power generation system 120 includes a combustor 1 which in this example is a fluidized bed reactor that receives a coal feed 124 and an adsorbent feed 125 , such as limestone, which facilitates the reaction within a fluidized bed 122 a.
- the combustor 122 can be a coal-fired boiler that is then replaced with a retrofit fluidized bed reactor, coal feed 124 and adsorbent feed 125 .
- a steam--based cycle 126 absorbs heat from the combustor 122 to generate electricity.
- the steam-based cycle 126 includes a heat exchanger 170 and a turbine 132 that is mounted on a shaft 134 .
- the turbine 132 is coupled through the shaft 134 to drive a generator 136 .
- the heat exchanger 170 is in communication with circuit 140 , which receives a hot exhaust stream from the combustor 122 as generally indicated by the arrows in the circuit 140 .
- the tubes of the circuit 140 and components of the turbine 132 are made of steel and have a maximum operating temperature.
- the combustor 122 produces a hot exhaust stream that is discharged through circuit 140 to the heat exchanger 170 .
- the hot exhaust stream heats water in the heat exchanger 170 to produce steam.
- the hot exhaust stream may then be recycled downstream from the heat exchanger 170 such that at least a portion of the product stream, such as carbon dioxide, is fed back into the combustor 122 .
- the steam in the steam-based cycle 126 expands over the turbine 132 to drive the generator 136 .
- the system 120 of FIG. 4 has been retrofit with efficiency enhancements to produce a retrofitted power generation system 120 ′ (retrofit system 120 ′).
- the retrofit system 120 ′ has been retrofitted with a super-critical carbon dioxide-based Brayton cycle 154 to enhance efficiency.
- the retrofit system 120 utilizes a portion of the pre-existing hardware of the system 120 , including the pre-existing turbine 132 and pre-existing heat exchanger 170 .
- a second (retrofit) working fluid circuit 150 ′ that extends through the combustor 122 is added.
- the retrofit system 120 ′′ also includes at least one additional, retrofit turbine 152 mounted on the shaft 134 .
- the super-critical carbon dioxide-based Brayton cycle 154 is thermally coupled through the combustor 122 and the prior steam-based cycle 126 is converted to a steam-based Rankine cycle 126 ′ that is in thermal-receiving communication with the super-critical carbon dioxide-based Brayton cycle 154 .
- superalloy tubes of the second working fluid circuit 150 ′ are added and are directly coupled through the combustor 122 .
- the addition of the super-critical carbon dioxide-based Brayton cycle 154 includes adding a retrofit compressor 156 , a retrofit first turbine 158 and a retrofit second turbine 160 .
- the prior steam--based cycle 126 is modified to add a retrofit heat exchanger 162 for thermal communication between the super-critical carbon dioxide-based Brayton cycle 154 and the steam-based Rankine cycle 126 .
- the retrofit compressor 156 , the retrofit first turbine 158 , the retrofit second turbine 160 and the pre-existing turbine 132 are mounted on the common shaft 134 to drive the generator 136 .
- the retrofit first turbine 158 and the retrofit second turbine 160 each includes a rotor having a disk 166 and a plurality of blades 168 mounted on the disk 166 .
- a working fluid such as carbon dioxide or a carbon dioxide-containing mixture (e.g., with helium) in the second working fluid circuit 150 ′ absorbs heat within the fluidized-bed 122 a and is then expanded over the retrofit first turbine 158 .
- the expanded working fluid is then circulated back into the combustor 122 for a reheat.
- the reheated working fluid expands over the retrofit second turbine 160 and then circulates to the retrofit heat exchanger 162 .
- the working fluid in the retrofit heat exchanger 162 heats water within the steam-based Rankine cycle 126 ′.
- the working fluid is then pressurized in the retrofit compressor 156 prior to circulating to the combustor 122 for another thermodynamic cycle.
- the heated steam from the heat exchanger 162 expands over the pre-existing turbine 132 and then circulates to a condenser 138 for another thermodynamic cycle.
- the retrofit system 120 ′ has enhanced efficiency in comparison with the system 120 with regard to carbon dioxide emissions per unit of electricity generated.
- the tubes of the second working fluid circuit 150 ′ and the disks 166 and blades 168 of the retrofit turbines 158 / 160 are made of superalloy materials.
- the second working fluid circuit 150 ′ and retrofit turbines 158 / 160 have a second maximum operating temperature that is greater than the maximum operating temperature of the circuit 140 and turbine 132 that include steel materials.
- the second working fluid circuit 150 ′ can thus be routed through the fluidized-bed 122 a, or the combustor 122 can be operated at a higher temperature.
- the combustor 122 operates in a temperature regime of up to 1300° F./705° C. and pressure of up to 6000 pounds per square inch/41 megapascals.
- the retrofit system 120 ′ can be operated more efficiently to improve carbon dioxide emissions per unit of generated electricity and to reduce levelized cost of energy.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engine Equipment That Uses Special Cycles (AREA)
Abstract
Description
- This disclosure relates to power plants for generating electricity.
- Existing coal-fired power plants that have been in operation for many years, such as supercritical pulverized coal plants, typically suffer from high carbon dioxide emissions. One approach to reduce carbon dioxide emissions is to outfit an existing plant with a post-combustion device, such as a chilled ammonia or hindered amine device, to capture carbon dioxide from combustion exhaust. Although such devices are effective in reducing net carbon dioxide emissions, the devices typically debit overall plant efficiency and thus increase levelized cost of energy.
- More recently, there have been proposals to regulate carbon dioxide emissions by capping emissions per unit of electricity produced. Because post-combustion devices debit plant efficiency, the carbon dioxide emissions per unit of generated electricity increases. Therefore, existing plants are ill-equipped to meet such regulations and are faced with the possibility of forced retirement.
-
- The various features and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.
-
FIG. 1 is a schematic view of a pre-existing power generation system. -
FIG. 2 is a schematic view of a retrofit power generation system based upon the pre-existing power generation system ofFIG. 1 . -
FIG. 3 is a schematic view of another example retrofit power generation system based upon the pre-existing power generation system ofFIG. 1 . -
FIG. 4 is a schematic view of another example pre-existing power generation system. -
FIG. 5 is a schematic view of a retrofit power generation system based upon the pre-existing power generation system ofFIG. 4 . -
FIG. 1 shows a schematic view of selected portions of a pre-existing power generation system 20 (“system 20”). The term “pre-existing” generally refers to thesystem 20 having been in operation for its intended use for some period of time. As disclosed herein, as an alternative to retiring thesystem 20, thesystem 20 can be retrofitted with new, more efficient hardware, while retaining at least some of the pre-existing hardware of thesystem 20, to produce more power per unit of coal or fuel input. As examples, a retrofit system as disclosed herein is expected to achieve 5-10% increase in overall net thermal efficiency, 10-30% lower carbon dioxide emissions, up to 25% reduction in levelized cost of energy and the ability to meet proposed regulations with regard to efficiency and emissions per unit of electricity produced. - The
system 20 includes acombustor 22, such as a coal-fired boiler, which receives aninput coal feed 24 a and aninput oxidant feed 24 b (e.g., air) that generate heat within thecombustor 22. A steam-based cycle 26 (power cycle) absorbs heat from thecombustor 22 to generate electricity. The steam-basedcycle 26 includes afirst turbine 28, asecond turbine 30 andthird turbine 32. Theturbines 28/30/32 are mounted on ashaft 34, which is coupled to drive agenerator 36. Thethird turbine 32 is in communication with acondenser 38, which is connected in circuit to thecombustor 22. Thecombustor 22,turbines 28/30/32 andcondenser 38 are connected within a closed loop, workingfluid circuit 40. For example, the workingfluid circuit 40 includes steel tubes that convey water, steam or both between thecombustor 22,turbines 28/30/32 andcondenser 38, as generally indicated by the arrows in theworking fluid circuit 40. - In operation, liquid water is discharged from the
condenser 38 into thecombustor 22. Thecombustor 22 generally operates in a temperature regime of less than 700° F./371° C. and pressure of less than 3000 pounds per square inch/20.5 megapascals due to the limits of the materials of the workingfluid circuit 40 and theturbines 28/30/32. The water absorbs heat within thecombustor 22 and turns to steam. The steam is then expanded over thefirst turbine 28. The expanded steam from thefirst turbine 28 is circulated back through thecombustor 22 for a reheat. The reheated steam is then expanded over thesecond turbine 30 and then thethird turbine 32. The expanded steam from thethird turbine 32 is condensed in thecondenser 38 prior to circulation into thecombustor 22 for another thermodynamic cycle. - In this example, the
system 20 utilizes relatively inefficient technology. For example, the tubes of the workingfluid circuit 40 and components of theturbines 28/30/32 are made of steel. In that regard, the workingfluid circuit 40 andturbines 28/30/32 have a maximum operating temperature to which the materials of these components can be exposed. For example, the temperature in thecombustor 22 is controlled using a water quench or the like to ensure that actual operating temperatures of the steam do not exceed the maximum operating temperature limit of the materials of the workingfluid circuit 40 and theturbines 28/30/32. Overall, the operating efficiency of thesystem 20 is limited by the maximum allowed temperature in thecombustor 22 and steam-basedcycle 26. Thus, even if carbon dioxide is captured from anexhaust 42 of thecombustor 22, thesystem 20 as-is has only limited ability to improve carbon dioxide emissions per unit of generated electricity and levelized cost of energy. - As will be appreciated from
FIG. 2 , thesystem 20 ofFIG. 1 has been retrofitted with efficiency enhancements to produce a retrofittedpower generation system 20′ (retrofit system 20′). In this disclosure, the term “retrofit” or variations thereof may be used to refer to an individual hardware component or to a system, for example. When used with reference to an individual hardware component for use in a system, the term indicates that the component was not part of the operable initial or prior system and is not a mere replacement in kind of a like component of the operable initial or prior system. When used with reference to a system, the term indicates that the system includes at least some pre-existing hardware components and at least one added hardware component that was not part of the operable initial or prior system and is not a mere replacement in kind of a like component of the operable initial or prior system. The modifying terms “pre-existing” and “retrofit” as used herein thus indicate a physical distinction between components and/or systems. - In this example, the
retrofit system 20′ utilizes a portion of the pre-existing hardware of thesystem 20, including thepre-existing combustor 22, thepre-existing turbines 28/30/32 and thepre-existing condenser 38. However, theworking fluid circuit 40 is replaced with a second (retrofit) workingfluid circuit 50 that is directly coupled through thecombustor 22 and theretrofit system 20′ includes at least one additional,retrofit turbine 52 mounted on theshaft 34. Although only oneretrofit turbine 52 is shown, it is to be understood thatadditional retrofit turbines 52 could be used. - In the
retrofit system 20′, theretrofit turbine 52, thecombustor 22, theturbines 28/30/32 andcondenser 38 are connected within the second workingfluid circuit 50. For example, the second workingfluid circuit 50 includes superalloy tubes that convey water, steam or both between thecombustor 22,retrofit turbine 52,turbines 28/30/32 and thecondenser 38, as generally indicated by the arrows in the second workingfluid circuit 50. A “superalloy” as used herein refers to a nickel-based, cobalt-based or nickel-iron-based alloy. - In operation, liquid water is discharged from the
condenser 38 into thecombustor 22. The water absorbs heat within thecombustor 22 and turns to steam. The steam is then expanded over theretrofit turbine 52. The expanded steam from theretrofit turbine 52 is then serially expanded over thefirst turbine 28, thesecond turbine 30 and thethird turbine 32. The expanded steam from thethird turbine 32 is then condensed in thecondenser 38 prior to being circulated to thecombustor 22 for another thermodynamic cycle. - The
retrofit system 20′ has enhanced efficiency in comparison with thesystem 20 with regard to carbon dioxide emissions per unit of electricity generated. For example, the tubes of the second workingfluid circuit 50 and components of theretrofit turbine 52 are made of superalloy materials. In that regard, the second workingfluid circuit 50 andretrofit turbine 52 have a second maximum operating temperature that is greater than the maximum operating temperature of the prior workingfluid circuit 40 andturbines 28/30/32 that include steel or other lower melting point materials. The second workingfluid circuit 50 can thus be routed through ahotter portion 22 a of thecombustor 22 than the prior workingfluid circuit 40, or thecombustor 22 can be operated at a higher temperature to generate higher temperature steam. For example, thecombustor 22 operates in a temperature regime of up to 1300° F./705° C. and pressure of up to 6000 pounds per square inch/41 megapascals. Once the higher temperature steam is expanded over theretrofit turbine 52, the steam cools to a temperature that is within the maximum operating temperature of theturbines 28/30/32. Thus, theretrofit system 20′ can be operated at higher, more efficient temperatures to improve carbon dioxide emissions per unit of generated electricity and to reduce levelized cost of energy. - As will be appreciated from another example of a retrofit in
FIG. 3 , thesystem 20 ofFIG. 1 is retrofitted with efficiency enhancements to produce a retrofittedpower generation system 20″ (retrofitsystem 20″). In this example, thesystem 20 has been retrofitted with a super-critical carbon dioxide-basedBrayton cycle 54 to enhance efficiency. Theretrofit system 20″ utilizes a portion of the pre-existing hardware of thesystem 20, including thepre-existing combustor 22,pre-existing turbine 32 andpre-existing condenser 38, The workingfluid circuit 40 is replaced with a second (retrofit) workingfluid circuit 50′ that extends through thecombustor 22. Theretrofit system 20″ also includes at least one additional, retrofitturbine 52′ mounted on theshaft 34. - The super-critical carbon dioxide-based
Brayton cycle 54 is thermally coupled through thecombustor 22 and the prior steam-basedcycle 26 is converted to a steam-basedRankine cycle 26′ that is in thermal-receiving communication with the super-critical carbon dioxide-basedBrayton cycle 54. - As an example of the retrofit, the prior steel tubes of the working
fluid circuit 40 are removed, including removal from thecombustor 22. Superalloy tubes of the second workingfluid circuit 50′ are added and are directly coupled through thecombustor 22, The addition of the super-critical carbon dioxide-basedBrayton cycle 54 includes adding aretrofit compressor 56, a retrofitfirst turbine 58 and a retrofitsecond turbine 60. The prior steam-basedcycle 26 is modified to add aretrofit heat exchanger 62 for thermal communication between the super-critical carbon dioxide-basedBrayton cycle 54 and the steam-basedRankine cycle 26′. Theretrofit compressor 56, the retrofitfirst turbine 58, the retrofitsecond turbine 60 and thepre-existing turbine 32 are mounted on thecommon shaft 34 to drive thegenerator 36. The retrofitfirst turbine 58 and the retrofitsecond turbine 60 each includes a rotor having adisk 66 and a plurality ofblades 68 mounted on thedisk 66. - In operation, a working fluid, such as carbon dioxide or a carbon dioxide-containing mixture (e.g., with helium), in the second working
fluid circuit 50′ absorbs heat within thecombustor 22 and is then expanded over the retrofitfirst turbine 58. The expanded working fluid is then circulated back into thecombustor 22 for a reheat. The reheated working fluid is then expanded over the retrofitsecond turbine 60 and then circulated to theretrofit heat exchanger 62. The working fluid in theretrofit heat exchanger 62 heats water within the steam-basedRankine cycle 26′. The working fluid is then pressurized in theretrofit compressor 56 prior to circulating to thecombustor 22 for another thermodynamic cycle. The heated steam from theheat exchanger 62 expands over thepre-existing turbine 32 and then circulates to thecondenser 38 for another thermodynamic cycle. - The
retrofit system 20″ has enhanced efficiency in comparison with thesystem 20 with regard to carbon dioxide emissions per unit of electricity generated. For example, the tubes of the second workingfluid circuit 50′ and thedisks 66 andblades 68 of theretrofit turbines 58/60 are made of superalloy materials. In that regard, the second workingfluid circuit 50′ and retrofitturbines 58/60 have a second maximum operating temperature that is greater than the maximum operating temperature of the prior workingfluid circuit 40 andturbines 28/30/32 that include steel materials. The second workingfluid circuit 50′ can thus be routed through ahotter portion 22 a of thecombustor 22 than the prior workingfluid circuit 40, or thecombustor 22 can be operated at a higher temperature to generate higher temperature working fluid. For example, thecombustor 22 operates in a temperature regime of up to 1300° F./705° C. and pressure of up to 6000 pounds per square inch/41 megapascals. Thus, theretrofit system 20″ can be operated at higher, more efficient temperatures to improve carbon dioxide emissions per unit of generated electricity and to reduce levelized cost of energy. -
FIG. 4 illustrates another example pre-existingpower generation system 120. In this example, the pre-existingpower generation system 120 includes a combustor 1 which in this example is a fluidized bed reactor that receives acoal feed 124 and anadsorbent feed 125, such as limestone, which facilitates the reaction within afluidized bed 122 a. Alternatively, thecombustor 122 can be a coal-fired boiler that is then replaced with a retrofit fluidized bed reactor,coal feed 124 andadsorbent feed 125. - A steam--based
cycle 126 absorbs heat from thecombustor 122 to generate electricity. The steam-basedcycle 126 includes a heat exchanger 170 and aturbine 132 that is mounted on ashaft 134. Theturbine 132 is coupled through theshaft 134 to drive agenerator 136. The heat exchanger 170 is in communication withcircuit 140, which receives a hot exhaust stream from thecombustor 122 as generally indicated by the arrows in thecircuit 140. Similar to thesystem 20, in thesystem 120 the tubes of thecircuit 140 and components of theturbine 132 are made of steel and have a maximum operating temperature. - In operation, the
combustor 122 produces a hot exhaust stream that is discharged throughcircuit 140 to the heat exchanger 170. The hot exhaust stream heats water in the heat exchanger 170 to produce steam. The hot exhaust stream may then be recycled downstream from the heat exchanger 170 such that at least a portion of the product stream, such as carbon dioxide, is fed back into thecombustor 122. The steam in the steam-basedcycle 126 expands over theturbine 132 to drive thegenerator 136. - As will be appreciated from
FIG. 5 , thesystem 120 ofFIG. 4 has been retrofit with efficiency enhancements to produce a retrofittedpower generation system 120′ (retrofit system 120′). In this example, theretrofit system 120′ has been retrofitted with a super-critical carbon dioxide-basedBrayton cycle 154 to enhance efficiency. Theretrofit system 120 utilizes a portion of the pre-existing hardware of thesystem 120, including thepre-existing turbine 132 and pre-existing heat exchanger 170. A second (retrofit) workingfluid circuit 150′ that extends through thecombustor 122 is added. Theretrofit system 120″ also includes at least one additional, retrofitturbine 152 mounted on theshaft 134. - The super-critical carbon dioxide-based
Brayton cycle 154 is thermally coupled through thecombustor 122 and the prior steam-basedcycle 126 is converted to a steam-basedRankine cycle 126′ that is in thermal-receiving communication with the super-critical carbon dioxide-basedBrayton cycle 154. - As an example of the retrofit, superalloy tubes of the second working
fluid circuit 150′ are added and are directly coupled through thecombustor 122. The addition of the super-critical carbon dioxide-basedBrayton cycle 154 includes adding aretrofit compressor 156, a retrofit first turbine 158 and a retrofitsecond turbine 160. The prior steam--basedcycle 126 is modified to add aretrofit heat exchanger 162 for thermal communication between the super-critical carbon dioxide-basedBrayton cycle 154 and the steam-basedRankine cycle 126. Theretrofit compressor 156, the retrofit first turbine 158, the retrofitsecond turbine 160 and thepre-existing turbine 132 are mounted on thecommon shaft 134 to drive thegenerator 136. The retrofit first turbine 158 and the retrofitsecond turbine 160 each includes a rotor having adisk 166 and a plurality ofblades 168 mounted on thedisk 166. - In operation, a working fluid, such as carbon dioxide or a carbon dioxide-containing mixture (e.g., with helium), in the second working
fluid circuit 150′ absorbs heat within the fluidized-bed 122 a and is then expanded over the retrofit first turbine 158. The expanded working fluid is then circulated back into thecombustor 122 for a reheat. The reheated working fluid expands over the retrofitsecond turbine 160 and then circulates to theretrofit heat exchanger 162. The working fluid in theretrofit heat exchanger 162 heats water within the steam-basedRankine cycle 126′. The working fluid is then pressurized in theretrofit compressor 156 prior to circulating to thecombustor 122 for another thermodynamic cycle. The heated steam from theheat exchanger 162 expands over thepre-existing turbine 132 and then circulates to acondenser 138 for another thermodynamic cycle. - The
retrofit system 120′ has enhanced efficiency in comparison with thesystem 120 with regard to carbon dioxide emissions per unit of electricity generated. For example, the tubes of the second workingfluid circuit 150′ and thedisks 166 andblades 168 of the retrofit turbines 158/160 are made of superalloy materials. Thus, the second workingfluid circuit 150′ and retrofit turbines 158/160 have a second maximum operating temperature that is greater than the maximum operating temperature of thecircuit 140 andturbine 132 that include steel materials. The second workingfluid circuit 150′ can thus be routed through the fluidized-bed 122 a, or thecombustor 122 can be operated at a higher temperature. For example, thecombustor 122 operates in a temperature regime of up to 1300° F./705° C. and pressure of up to 6000 pounds per square inch/41 megapascals. Thus, theretrofit system 120′ can be operated more efficiently to improve carbon dioxide emissions per unit of generated electricity and to reduce levelized cost of energy. - Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments.
- The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.
Claims (18)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/448,909 US20130269345A1 (en) | 2012-04-17 | 2012-04-17 | Retrofit for power generation system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/448,909 US20130269345A1 (en) | 2012-04-17 | 2012-04-17 | Retrofit for power generation system |
Publications (1)
Publication Number | Publication Date |
---|---|
US20130269345A1 true US20130269345A1 (en) | 2013-10-17 |
Family
ID=49323837
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/448,909 Abandoned US20130269345A1 (en) | 2012-04-17 | 2012-04-17 | Retrofit for power generation system |
Country Status (1)
Country | Link |
---|---|
US (1) | US20130269345A1 (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140102098A1 (en) * | 2012-10-12 | 2014-04-17 | Echogen Power Systems, Llc | Bypass and throttle valves for a supercritical working fluid circuit |
CN105888755A (en) * | 2016-06-07 | 2016-08-24 | 西安交通大学 | Complex working medium thermal power generation system and working method thereof |
CN105971679A (en) * | 2016-07-13 | 2016-09-28 | 西安热工研究院有限公司 | Supercritical water gasification and supercritical carbon dioxide Brayton cycle joint production system |
WO2016164153A1 (en) * | 2015-04-09 | 2016-10-13 | General Electric Company | Regenerative thermodynamic power generation cycle systems, and methods for operating thereof |
CN106089337A (en) * | 2016-08-10 | 2016-11-09 | 西安热工研究院有限公司 | Supercritical CO for waste heat recovery2with organic Rankine association circulating power generation system |
US20160369746A1 (en) * | 2015-06-19 | 2016-12-22 | Rolls-Royce Corporation | Engine driven by sc02 cycle with independent shafts for combustion cycle elements and propulsion elements |
KR20180101010A (en) * | 2017-03-03 | 2018-09-12 | 대우조선해양 주식회사 | Power Generation System and Method Using Supercritical Carbon Dioxide |
US11098615B2 (en) * | 2016-09-22 | 2021-08-24 | Gas Technology Institute | Power cycle systems and methods |
CN114876595A (en) * | 2022-06-08 | 2022-08-09 | 西安交通大学 | Thorium-based molten salt reactor supercritical carbon dioxide power generation system and operation method thereof |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3971211A (en) * | 1974-04-02 | 1976-07-27 | Mcdonnell Douglas Corporation | Thermodynamic cycles with supercritical CO2 cycle topping |
US6174132B1 (en) * | 1994-02-22 | 2001-01-16 | Hitachi, Ltd. | Steam-turbine power plant and steam turbine |
US20080250790A1 (en) * | 2007-04-13 | 2008-10-16 | Shinya Imano | High-temperature steam turbine power plant |
US7926274B2 (en) * | 2007-06-08 | 2011-04-19 | FSTP Patent Holding Co., LLC | Rankine engine with efficient heat exchange system |
US20120216536A1 (en) * | 2011-02-25 | 2012-08-30 | Alliance For Sustainable Energy, Llc | Supercritical carbon dioxide power cycle configuration for use in concentrating solar power systems |
-
2012
- 2012-04-17 US US13/448,909 patent/US20130269345A1/en not_active Abandoned
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3971211A (en) * | 1974-04-02 | 1976-07-27 | Mcdonnell Douglas Corporation | Thermodynamic cycles with supercritical CO2 cycle topping |
US6174132B1 (en) * | 1994-02-22 | 2001-01-16 | Hitachi, Ltd. | Steam-turbine power plant and steam turbine |
US20080250790A1 (en) * | 2007-04-13 | 2008-10-16 | Shinya Imano | High-temperature steam turbine power plant |
US7926274B2 (en) * | 2007-06-08 | 2011-04-19 | FSTP Patent Holding Co., LLC | Rankine engine with efficient heat exchange system |
US20120216536A1 (en) * | 2011-02-25 | 2012-08-30 | Alliance For Sustainable Energy, Llc | Supercritical carbon dioxide power cycle configuration for use in concentrating solar power systems |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140102098A1 (en) * | 2012-10-12 | 2014-04-17 | Echogen Power Systems, Llc | Bypass and throttle valves for a supercritical working fluid circuit |
WO2016164153A1 (en) * | 2015-04-09 | 2016-10-13 | General Electric Company | Regenerative thermodynamic power generation cycle systems, and methods for operating thereof |
US20160369746A1 (en) * | 2015-06-19 | 2016-12-22 | Rolls-Royce Corporation | Engine driven by sc02 cycle with independent shafts for combustion cycle elements and propulsion elements |
US9982629B2 (en) * | 2015-06-19 | 2018-05-29 | Rolls-Royce Corporation | Engine driven by SC02 cycle with independent shafts for combustion cycle elements and propulsion elements |
CN105888755A (en) * | 2016-06-07 | 2016-08-24 | 西安交通大学 | Complex working medium thermal power generation system and working method thereof |
CN105971679A (en) * | 2016-07-13 | 2016-09-28 | 西安热工研究院有限公司 | Supercritical water gasification and supercritical carbon dioxide Brayton cycle joint production system |
CN106089337A (en) * | 2016-08-10 | 2016-11-09 | 西安热工研究院有限公司 | Supercritical CO for waste heat recovery2with organic Rankine association circulating power generation system |
US11098615B2 (en) * | 2016-09-22 | 2021-08-24 | Gas Technology Institute | Power cycle systems and methods |
KR20180101010A (en) * | 2017-03-03 | 2018-09-12 | 대우조선해양 주식회사 | Power Generation System and Method Using Supercritical Carbon Dioxide |
KR102276368B1 (en) * | 2017-03-03 | 2021-07-12 | 대우조선해양 주식회사 | Power Generation System and Method Using Supercritical Carbon Dioxide |
CN114876595A (en) * | 2022-06-08 | 2022-08-09 | 西安交通大学 | Thorium-based molten salt reactor supercritical carbon dioxide power generation system and operation method thereof |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20130269345A1 (en) | Retrofit for power generation system | |
JP5317833B2 (en) | Steam turbine power generation equipment | |
US8887503B2 (en) | Recuperative supercritical carbon dioxide cycle | |
JP2011047364A (en) | Steam turbine power generation facility and operation method for the same | |
US20100180567A1 (en) | Combined Power Augmentation System and Method | |
US8281565B2 (en) | Reheat gas turbine | |
US20100170218A1 (en) | Method for expanding compressor discharge bleed air | |
CN109653875B (en) | Fuel preheating system for combustion turbine engine | |
JP2009180222A (en) | Reheat gas and exhaust gas regenerator system for a combined cycle power plant | |
WO2013151028A1 (en) | Gas turbine engine system equipped with rankine cycle engine | |
US20100242429A1 (en) | Split flow regenerative power cycle | |
US20120317973A1 (en) | Asymmetrical Combined Cycle Power Plant | |
Rao et al. | An evaluation of advanced combined cycles | |
US20100077722A1 (en) | Peak load management by combined cycle power augmentation using peaking cycle exhaust heat recovery | |
EP2587007A2 (en) | System and method for operating heat recovery steam generators | |
JP2012132454A (en) | System and method for using gas turbine intercooler heat in bottoming steam cycle | |
JP2015040565A (en) | Duct fired combined cycle system | |
JPH11173111A (en) | Thermal power plant | |
KR101664895B1 (en) | Power generation system based on Brayton cycle | |
EP2752566B1 (en) | Gas turbine cooling system, and gas turbine cooling method | |
CN109715916B (en) | Power cycle system and method | |
JP2013538311A (en) | Gas turbine device with improved exergy recovery device | |
US20140069078A1 (en) | Combined Cycle System with a Water Turbine | |
Dutta et al. | Simple recuperated S-CO2 cycle revisited: Optimization of operating parameters for maximum cycle efficiency | |
US8869532B2 (en) | Steam turbine utilizing IP extraction flow for inner shell cooling |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: PRATT & WHITNEY ROCKETDYNE, INC., CALIFORNIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SONWANE, CHANDRASHEKHAR;SPROUSE, KENNETH M.;SIGNING DATES FROM 20120405 TO 20120409;REEL/FRAME:028064/0892 |
|
AS | Assignment |
Owner name: WELLS FARGO BANK, NATIONAL ASSOCIATION, NORTH CARO Free format text: SECURITY AGREEMENT;ASSIGNOR:PRATT & WHITNEY ROCKETDYNE, INC.;REEL/FRAME:030628/0408 Effective date: 20130614 |
|
AS | Assignment |
Owner name: U.S. BANK NATIONAL ASSOCIATION, CALIFORNIA Free format text: SECURITY AGREEMENT;ASSIGNOR:PRATT & WHITNEY ROCKETDYNE, INC.;REEL/FRAME:030656/0615 Effective date: 20130614 |
|
AS | Assignment |
Owner name: AEROJET ROCKETDYNE OF DE, INC., CALIFORNIA Free format text: CHANGE OF NAME;ASSIGNOR:PRATT & WHITNEY ROCKETDYNE, INC.;REEL/FRAME:030902/0313 Effective date: 20130617 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |
|
AS | Assignment |
Owner name: AEROJET ROCKETDYNE OF DE, INC. (F/K/A PRATT & WHIT Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:U.S. BANK NATIONAL ASSOCIATION;REEL/FRAME:039597/0890 Effective date: 20160715 |