DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Claim Objections
Claims are objected to because of the following informalities:
Cl.1: “in parallel with first” is believed to be in error for --in parallel with the first--
Cl.19: “to reduces the oxygen” is believed to be in error for --to reduce the oxygen--
Appropriate correction is required.
Claim Rejections - 35 USC § 102/103
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 1-4, 6, 8-10, and 13-15 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Leach 20170356342, and alternatively under 103 as being unpatentable over Leach in view of Bernero 20160356495.
Regarding claim 1, Leach teaches a gas turbine engine (Fig 1) comprising:
a fuel conduit (from 75) fluidly coupled to a fuel source (79),
a first fuel circuit (incl. 73, 83, and 58) fluidly coupled to the fuel conduit to receive a first portion of the fuel from the fuel source (Fig 2), the first fuel circuit including a first fuel manifold (58) to distribute the first portion of the fuel at a first temperature (Fig 2);
a second fuel circuit (incl. 74, 84, and 57) arranged in parallel with first fuel circuit (Fig 2) and fluidly coupled to the fuel conduit to receive a second portion of the fuel from the fuel source (Fig 2), the second fuel circuit including a second fuel manifold (57) to distribute the second portion of the fuel at a second temperature (Fig 2), the second temperature being less than the first temperature (70, 72, 73, 74 are operable to heat fuel to different temperatures; [0023, 31-32]);
an annular combustor (16 defined by annular casings as evidenced by cap depicted in Fig 3) including a combustion chamber (required for combustion; Fig 1); and
a plurality of fuel nozzles (of PM1-3) that inject fuel into the combustion chamber of the annular combustor (Figs 1-3), the plurality of fuel nozzles being arranged in an annular configuration (Fig 3) including a first nozzle (e.g. PM3 at bottom of Fig 3) and a second nozzle (e.g. PM2 to either side of PM3), the second nozzle being adjacent to the first nozzle (Fig ),
the first nozzle being fluidly connected to the first circuit via the first fuel manifold to receive the first portion of the fuel at the first temperature (Figs 2-3),
the second nozzle being fluidly connected to the second circuit via the second fuel manifold to receive the second portion of the fuel at the second temperature (Figs 2-3),
wherein the first fuel circuit and the second fuel circuit are arranged such that injection of the first portion of the fuel via the first nozzle and the second portion of the fuel via the second nozzle occurs simultaneously during operation of the gas turbine engine ([0028]).
Additionally, Bernero teaches the same staged fuel injection systems can be used for silo/can combustors and annular combustors ([0081]). Bernero also teaches how to arrange staged fuel nozzles for a can combustor (Fig 15b) versus an annular combustor (Fig 15a).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to apply the staged fuel system of Leach to an annular combustor as taught by Bernero because Bernero teaches the substitutional equivalence of staged annular combustors and staged can combustors (Bernero, [0081]). Additionally, it has been held that combining or simple substitution of prior art elements according to known methods to yield predictable results renders the limitation obvious (see MPEP 2141 (III)). In this case, combining the fuel system (for fuel-staged can combustors) of Leach with the annular fuel-staged combustor as taught by Bernero, using the teachings of Bernero to arrange the staged fuel nozzles analogously between can and annular configurations, would have yielded the predictable results of a functional, efficient gas turbine engine combustor system with the fuel management properties of Leach and an annularly staged combustor.
Regarding claim 2, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach further teaches the first temperature is higher than two hundred degrees Fahrenheit during at least some modes of operation (such as greater than 10% load; [0005,0032]) for enhanced efficiency (around 365°F or more; [0032]).
Regarding claim 3, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach further teaches the second temperature is less than the first temperature by twenty degrees Fahrenheit to five hundred degrees Fahrenheit. This is a functional limitation that only requires sufficient structure to perform the function (MPEP2173.05(g), 2114(I-II)). In this case, Leach teaches the ability to supply fuel temperatures of less than 120°F to greater than 365°F ([0005,0032]), and individually controlling the temperature of the fuel in each fuel circuit ([0028, 31-32]); thus Leach teaches the ability to provide the second temperature fuel up to at least 245°F less than the first temperature.
Regarding claim 4, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach further teaches the second fuel circuit includes a heat exchanger thermally coupled to a heat source to heat the second portion of the fuel to the second temperature, the heat exchanger being upstream of the second fuel manifold relative to a flow of the second portion of the fuel in the second fuel circuit (heat exchanger 74 is coupled to a heat source to heat the second portion of the fuel to a corresponding second temperature upstream of the manifold 57; [0023, 31-32]).
Regarding claim 6, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach further teaches the first fuel circuit includes a heat exchanger (73) thermally coupled to a heat source to heat the first portion of the fuel to the first temperature, the heat exchanger being upstream of the first fuel manifold relative to a flow of the first portion of the fuel in the first fuel circuit (heat exchanger 73 is coupled to a heat source to heat the first portion of the fuel to a corresponding first temperature upstream of the corresponding manifold 58; [0023, 31-32]).
Regarding claim 8, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach further teaches a core air flowpath (through 12, 14, 16, 18, 20, 40) including a compressor section (14), the combustor, and a turbine section (18), one of the compressor section, the annular combustor, or the turbine section being the heat source (heat produced by the compression and combustion and left in the flow after expansion in the turbine is transferred to the water 50 to heat 70, 72, 73, 74).
Regarding claim 9, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach further teaches the first nozzle is one nozzle of a plurality of fuel nozzles in a first set of fuel nozzles (the plurality of a first set of fuel nozzles being one of the set of PM3s), each fuel nozzle of the first set of fuel nozzles being fluidly coupled to the first fuel manifold (Fig 2) to receive a portion of the first portion of the fuel from the first fuel manifold at the first temperature (Fig 2), and wherein the second nozzle is one nozzle of a plurality of fuel nozzles in a second set of fuel nozzles (the plurality of a second set of fuel nozzles being the set of PM2s), each fuel nozzle of the second set of fuel nozzles being fluidly coupled to the second fuel manifold to receive a portion of the second portion of the fuel from the second fuel manifold at the second temperature (corresponding one of 57, 58; Fig 2).
Regarding claim 10, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach further teaches the fuel nozzles of the first set of fuel nozzles and the fuel nozzles of the second set of fuel nozzles are arranged in an alternating fashion, such that one fuel nozzle of the first set of fuel nozzles is adjacent to two fuel nozzles of the second set of fuel nozzles and one fuel nozzle of the second set of fuel nozzles is adjacent to two fuel nozzles of the first set of fuel nozzles (Fig 3 shows at least an alternating arrangement of two PM2s and two PM3s).
Regarding claim 13, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach further teaches the plurality of fuel nozzles is aligned in a circumferential direction of the annular combustor (Fig 3).
Additionally, Bernero teaches how to modify groupings of fuel nozzles depending on the combustor being a can combustor or an annular combustor, and in both combustor systems, the fuel nozzles are aligned in a circumferential direction (Fig 15; [0081-82]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to apply the staged fuel system of Leach to an annular combustor as taught by Bernero because Bernero teaches the substitutional equivalence of staged annular combustors and staged can combustors (Bernero, [0081]). Additionally, it has been held that combining or simple substitution of prior art elements according to known methods to yield predictable results renders the limitation obvious (see MPEP 2141 (III)). In this case, combining the fuel system (for fuel-staged can combustors) of Leach with the annular fuel-staged combustor as taught by Bernero, using the teachings of Bernero to arrange the staged fuel nozzles analogously between can and annular configurations, would have yielded the predictable results of a functional, efficient gas turbine engine combustor system with the fuel management properties of Leach and an annularly staged combustor.
Regarding claim 14, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach further teaches the first fuel circuit includes a first fuel metering unit fluidly connected to the first fuel manifold,
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the second fuel circuit includes a second fuel metering unit fluidly connected to the second fuel manifold (valves in Fig 2 above provide fuel metering).
Regarding claim 15, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach further teaches the first fuel metering unit is upstream of the first fuel manifold relative to a first portion of the fuel flowing in the first fuel circuit, and the first fuel metering unit is operable to provide a first flowrate of the first portion of the fuel to the first fuel manifold, and wherein the second fuel metering unit is upstream of the second fuel manifold relative to a second portion of the fuel flowing in the second fuel circuit, and the second fuel metering unit is operable to provide a second flowrate of the second portion of the fuel to the second fuel manifold (in Fig 2 above, all valves are upstream of respective manifolds to provide respective flowrates of respective fuel portions at respective temperatures thereto).
Claim Rejections - 35 USC § 103
Claims 5, 7, and 19-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over both Leach, and Leach in view of Bernero, and each in further view of Miller 10215097.
Regarding claims 5 and 7, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach further teaches heating fuel (up to 392°F) for increased gas turbine efficiency (by reducing the amount of fuel required to achieve the desired firing temperature; [0005]).
Leach and Leach in view of Bernero do not teach a de-oxygenation system upstream of the heat exchanger relative to the flow of the fuel, the de-oxygenation system being operable to reduce the oxygen content of the fuel supplied to heat exchanger.
However, Miller teaches a gas turbine engine (Fig 1) comprising:
a combustor (116) including a combustion chamber (in 116);
at least one nozzle to inject fuel into the combustion chamber of the combustor (at 207),
a fuel circuit (from 208 to 207) including a heat exchanger (heat exchangers 220, 218) thermally coupled to a heat source (Fig 4), the heat exchanger being upstream of the fuel nozzle(s) (Fig 4), and
a de-oxygenation system (212) upstream of the heat exchanger relative to the flow of the fuel (Fig 4), the de-oxygenation system being operable to reduce the oxygen content of the fuel supplied to the heat exchanger in order to mitigate coke formation at high fuel temperatures. (col.5 l.62 – col.6 l.6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Leach (and Leach in view of Bernero) to include the deoxygenation system upstream of all the heat exchangers as taught by Miller, in order to mitigate coke formation at high fuel temperatures (col.5 l.62 – col.6 l.6).
Regarding claim 19, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach further teaches the first and second fuel circuits each containing heat exchanger(s) for heating the fuel (73, 74); and heating fuel (up to 392°F) for increased gas turbine efficiency (by reducing the amount of fuel required to achieve the desired firing temperature; [0005]).
Leach and Leach in view of Bernero teach do not teach a de-oxygenation system in fluid communication with the fuel conduit at a position upstream of each of the first fuel circuit and the second fuel circuit, the de-oxygenation system operable to reduce the oxygen content of the first portion of the fuel and the second portion of the fuel supplied to each of the first fuel circuit and the second fuel circuit, respectively.
However, Miller teaches a gas turbine engine (Fig 1) comprising:
a combustor (116) including a combustion chamber (in 116);
at least one nozzle to inject fuel into the combustion chamber of the combustor (at 207),
a fuel circuit (from 208 to 207) including a heat exchanger (heat exchangers 220, 218) thermally coupled to a heat source (Fig 4), the heat exchanger being upstream of the fuel nozzle(s) (Fig 4), and
a de-oxygenation system (212) upstream of the heat exchanger relative to the flow of the fuel (Fig 4), the de-oxygenation system being operable to reduce the oxygen content of the fuel supplied to the heat exchanger in order to mitigate coke formation at high fuel temperatures. (col.5 l.62 – col.6 l.6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Leach (and Leach in view of Bernero) to include the deoxygenation system upstream of all the heat exchangers as taught by Miller, in order to mitigate coke formation at high fuel temperatures (col.5 l.62 – col.6 l.6).
Regarding claim 20, Leach in view of Miller and Leach in view of Bernero and Miller teaches all the limitations of the claimed invention as discussed above. Leach further teaches the first fuel circuit includes a first heat exchanger thermally coupled to a heat source to heat the first portion of the fuel to the first temperature, the first heat exchanger being upstream of the first fuel manifold relative to a flow of the fuel in the first fuel circuit, and wherein the second fuel circuit includes a second heat exchanger thermally coupled to a heat source to heat the second portion of the fuel to the second temperature, the second heat exchanger being upstream of the second fuel manifold relative to a flow of the fuel in the second fuel circuit (each fuel circuit includes at least one heat exchanger of 70, 72, 73, 74 coupled to a heat source to heat the fuel to a corresponding temperature upstream of a corresponding manifold of 56, 57, 58; [0023, 31-32]; Fig 2).
Claims 16-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over both Leach, and Leach in view of Bernero, and each in further view of Endo 11421886.
Regarding claims 16-18, Leach and Leach in view of Bernero teach all the limitations of the claimed invention as discussed above. Leach and Leach in view of Bernero do not teach (claim 16) the first fuel metering unit and the second fuel metering unit are configured to operate in concert with each other to maintain a constant fuel ratio of the first flowrate to the second flowrate when changing each of the first flowrate and the second flowrate; (claim 17) a ratio of the first flowrate to the second flowrate is from 0.2-20; (claim 18) a ratio of the first flowrate to the second flowrate is from 5-10.
However, Endo teaches using corresponding fuel metering units (65, 66a-b, 67) upstream of corresponding fuel manifolds (Fig 4), each fuel metering unit connected to a shared control device (100) to tailor precise fuel flows and fuel flow ratios to the different manifolds and fuel nozzles (Figs 1, 4). The system having electronic control and separate fuel metering units is thus capable of maintaining constant ratio of flow rates while changing the flow rates for at least some period of time, the metering units being separate modulating valves are capable of being used to achieve a wide range of fuel ratios ranging at least from 5-10 (which falls in the claimed ratios).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Leach and Leach in view of Bernero to use modulating valves and a digital controller as taught by Endo in order to provide precise fuel control to individual manifolds (col.2 ll.29-38).
Response to Arguments
Applicant's arguments filed 22 December 2025 have been fully considered but they are not persuasive; or they are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Applicant asserts that amending claims 11-12 into claim 1 renders the claims patentable over Leach.
Claims 11-12 were previously rejected over different prior art because the other prior art was viewed to be the best art for rejecting those claims. This does not mean that Leach does not teach the subject matter of claims 11-12. In light of the further amendments made to claim 1 (which extend beyond merely rolling claims 11-12 into claim 1), the rejections have been reformulated (in some cases involving new prior art references). Amended claim 1 is rejected as discussed above.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHANIE SEBASCO CHENG whose telephone number is (469)295-9153. The examiner can normally be reached on 1000-1600 ET.
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/STEPHANIE SEBASCO CHENG/Primary Examiner, Art Unit 3741