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 .
Election/Restrictions
Claims 23-26, 31-35 and 39-40 were withdrawn and the restriction was made final in the Non-Final rejection filed on 08/07/2025. Therefore, claim 35 should be indicated as Withdrawn. After withdrawal, the dependency of claim 35 may not be changed.
Claims 21-22, 27-30, 36-38 and 41-44 are currently being examined.
Claim Objections
Claims 22, 29-30, 36-37 and 41 are objected to because of the following informalities:
Claim 22: in line 2, “the second portion” should read as – the second portion of the flowline --.
Claims 29-30 and 36: in multiple instances in each of claims 29 and 36 and in one instance in claim 30, “first trim heat exchanger” should read as –
Claim 29: in line 13, “fourth portion” should read as –third portion --.
Claim 37: in line 2, “a portion of the fuel” should read as – [[a]] the second portion of the fuel --.
Claim 41: in line 4, “and absorb the first heat” should read as -- and absorbing the first heat --.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 36-38 and 43-44 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 36 recites “cause the second valve to block the fuel from flowing to a portion of the flowline in which the portion of the second heat is absorbed from the fuel during the second engine operations” which is not supported by the original disclosure given the prior limitations required in claim 36.
The specification does not describe this recitation and elected Species D drawn to Fig. 6 does not show this recitation. In Fig. 6 and as described in specification [0077]-[0078], a first portion of fuel passing through waste heat recovery heat exchanger 210 absorbs heat and flows downstream of 210 along trunk section 205 of flowline 602; second branch 604 extends from second valve 224 coupled to trunk section 205 upstream of 210 to second mixer 228 coupled to trunk section 205 downstream of 210; a second portion of fuel passing through second branch 604 bypasses 210 such that the second portion of fuel is not heated in 210 and is therefore cooler than the first portion of fuel; second branch section 604 enables the relatively colder second portion of fuel to bypass waste heat recovery heat exchanger 210 and mix with the relatively hotter first portion of fuel in the second mixer 228 when a temperature of the fuel is to be reduced, i.e., a portion of the second heat is absorbed by the second portion of fuel in the second mixer 228 coupled to trunk section 205, i.e., a portion of the flowline, but only when second valve 224 does not block the second portion of the fuel from flowing to the portion of the flowline. When second valve 224 blocks fuel flowing through second branch 604, a portion of the second heat is not absorbed in the portion of the flowline since the cooler second fuel portion does not flow in the portion of the flowline and does not mix with the first portion of fuel.
Claims dependent upon claim 36 are also rejected as failing to comply with the written description requirement for the same reasons as base claim 36.
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 36-38 and 43-44 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 36 recites “cause the second valve to block the fuel from flowing to a portion of the flowline in which the portion of the second heat is absorbed from the fuel during the second engine operations” which is unclear as to whether each instance of “the fuel” means a first portion of the fuel recited earlier in the claim or means a second portion of the fuel recited earlier in the claim or means another portion of fuel.
In addition, this recitation is unclear in light of elected Species D drawn to Fig. 6. In Fig. 6, a first portion of fuel passing through waste heat recovery heat exchanger 210 absorbs heat and flows downstream of 210 along trunk section 205 of flowline 602; second branch 604 extends from second valve 224 coupled to trunk section 205 upstream of 210 to second mixer 228 coupled to trunk section 205 downstream of 210; a second portion of fuel passing through second branch 604 bypasses 210 such that the second portion of fuel is not heated in 210 and is therefore cooler than the first portion of fuel; second branch section 604 enables the relatively colder second portion of fuel to bypass waste heat recovery heat exchanger 210 and mix with the relatively hotter first portion of fuel in the second mixer 228 when a temperature of the fuel is to be reduced, i.e., a portion of the second heat is absorbed by the second portion of fuel in the second mixer 228 coupled to trunk section 205, i.e., a portion of the flowline, but only when second valve 224 does not block the second portion of the fuel from flowing to the portion of the flowline. When second valve 224 blocks fuel flowing through second branch 604, a portion of the second heat is not absorbed in the portion of the flowline since the cooler second fuel portion does not flow in the portion of the flowline and does not mix with the first portion of fuel.
For current examination purposes, the recitation is interpreted as: cause the second valve to block the second portion of the fuel from flowing to a portion of the flowline to prevent the portion of the second heat being absorbed from the first portion of fuel during the second engine operations.
Claims dependent upon claim 36 are also rejected as being indefinite for the same reasons as base claim 36.
Claim 38 recites “wherein the portion of the fuel is a first portion, further including a mixer to mix the first portion of the fuel with a second portion of the fuel that passed through the waste heat recovery heat exchanger” which is unclear since claim 36 from which claim 38 indirectly depends recites “a first portion of the fuel flows to the waste heat recovery heat exchanger” and claim 36 recites “a second portion of the fuel to bypass the waste heat recovery heat exchanger” such that the recitation of claim 38 contradicts the recitations in claim 36.
For current examination purposes, the recitation is interpreted as: further including a mixer to mix the second portion of the fuel that bypasses the waste heat recovery heat exchanger with the first portion of the fuel that passed through the waste heat recovery heat exchanger.
Claim Rejections - 35 USC § 102
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 (i.e., changing from AIA to pre-AIA ) 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.
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.
Claim(s) 21-22 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Brady 20230358180.
Regarding independent claim 21, Brady teaches a system (Fig. 3) comprising:
a flowline (fuel line from LH2 tank 306 to nozzles 304 of combustor 124 in Fig. 3);
a fuel tank (306 Fig. 3) coupled to a first end of the flowline (306 is coupled to first end of flowline in Fig. 3);
a combustor (124 Fig. 3) of a gas turbine engine (100 Figs. 2-3) coupled to a second end of the flowline (combustor 124 is coupled to second end of flowline via nozzles 304 in Fig. 3), the flowline to carry fuel from the fuel tank to the combustor (flowline carries fuel from 306 to 124);
a trim heat exchanger (320 Fig. 3) coupled to a first portion of the flowline (320 is coupled to a first portion of flowline in Fig. 3), the fuel to absorb first heat in the trim heat exchanger as the fuel flows through the first portion of the flowline ([0050] describes hydrogen fuel flowing through first portion of conduit 302 of flowline flowing through trim heat exchanger 320 has a thermal energy transfer which occurs between the fuel and air 152 entering compressor 122; [0052] also describes the hydrogen is warmed by the air 152 in 320, i.e., the hydrogen absorbs first heat in 320);
a valve (312 Fig. 3) coupled to the flowline to control a flow rate of the fuel in the first portion of the flowline ([0047] describes when valve 312 is open, cryogenic hydrogen flows towards the hydrogen pump 314 which pumps the cryogenic hydrogen through the conduit(s) 302 of the flowline and when valve 312 is closed the cryogenic hydrogen loops back to fuel tank 306); and
a waste heat recovery heat exchanger (labeled in annotated Fig. 3) positioned in an exhaust section (128 Fig. 3) of the gas turbine engine (waste heat recovery heat exchanger is positioned in exhaust section 128 in annotated Fig. 3), the waste heat recovery heat exchanger coupled to a second portion of the flowline (as shown in annotated Fig. 3, waste heat recovery heat exchanger is coupled to a second portion of the flowline), the fuel to absorb second heat in the waste heat recovery heat exchanger from core exhaust waste heat ([0053] describes conduit(s) 302 of second portion of flowline can be positioned in the outer casing 118 in FIG. 2 of the gas turbine 100 and can form loops that are positioned at least partially around a perimeter of the exhaust section 128 that enables the thermal energy from the combustion gases 160, i.e., core exhaust waste heat, to convert the hydrogen to a gaseous or super-critical phase in preparation for combustion, i.e., the hydrogen absorbs second heat in the waste heat recovery heat exchanger), wherein a portion of at least one of the first heat or the second heat is absorbable from the fuel after the fuel exits the waste heat recovery heat exchanger (after the hydrogen fuel exits the waste heat recovery heat exchanger, a portion of the first heat and a portion of the second heat are absorbable from the fuel since the fuel has absorbed first heat in 320 and second heat in the waste heat recovery heat exchanger).
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Regarding claim 22, Brady teaches the first portion of the flowline is positioned upstream of the second portion (as shown in annotated Fig. 3, the first portion of flowline through 302 is upstream of second portion of flowline through the waste heat recovery heat exchanger).
Claim Rejections - 35 USC § 103
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 21-22, 27-28 and 41 is/are rejected under 35 U.S.C. 103 as being unpatentable over Minelli et al. 20250198338 in view of Brady 20230358180.
Regarding independent claim 21, Minelli teaches a system comprising:
a flowline (labeled in annotated Fig. 7C);
a fuel tank (50 Fig. 7C; para. 0428) coupled to a first end (labeled in annotated Fig. 7C) of the flowline;
a combustor (16 Fig. 7C; para. 0428) of a gas turbine engine (Fig. 1) coupled to a second end (labeled in annotated Fig. 7C) of the flowline, the flowline to carry fuel from the fuel tank to the combustor (intended use but flowline in Fig. 7C is for carrying fuel from 50 to 16 per para. 0417 which describes first embodiment of Fig. 6 with Fig. 7C having some similar components);
a trim heat exchanger (1006 Fig. 7C) coupled to a first portion of the flowline (labeled in annotated Fig. 7C; 1006 is coupled to first portion of flowline), the fuel to absorb first heat in the trim heat exchanger as the fuel flows through the first portion of the flowline (first heat from oil is transferred to the fuel in 1006 per para. 0419);
and
a waste heat recovery heat exchanger (7010 Fig. 7C) of the gas turbine engine (per para. 0427 7010 is turbine case cooling (TCC) systems which is part of the gas turbine engine), the waste heat recovery heat exchanger coupled to a second portion of the flowline (labeled in annotated Fig. 7C; 7010 is coupled to second portion of flowline), the fuel to absorb second heat in the waste heat recovery heat exchanger (per para. 0427, 7010 may include turbine case cooling (TCC) systems in which the fuel absorbs second heat from turbine case cooling system components, such that 7010 recovers waste heat from the turbine case cooling system components by transferring the second heat to the fuel), wherein a portion of at least one of the first heat or the second heat is absorbable from the fuel after the fuel exits the waste heat recovery heat exchanger (fuel exiting 7010 into part of flowline extending from 7010 to 16 in annotated Fig. 7C may have at least a portion of at least one of first heat or second heat absorbed by conduits carrying fuel through that part of flowline as well as absorbed by a portion of fuel flow which has exited 1004 and flows through valve 7011 to bypass 7010 to flow straight to part of flowline extending from outlet of 7010 since this portion of fuel flow is cooler and has absorbed less heat than a portion of fuel which flows from valve 7011 to and through 7010 absorbing second heat in addition to first heat previously absorbed in 1006).
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Minelli does not explicitly teach in Fig. 7C a valve coupled to the flowline to control a flow rate of the fuel in the first portion of the flowline, and the waste heat recovery heat exchanger positioned in an exhaust section of the gas turbine engine, the fuel to absorb the second heat in the waste heat recovery heat exchanger from core exhaust waste heat.
Minelli further teaches in Fig. 6 a valve coupled to a flowline to control a flow rate of the fuel in a first portion of the flowline (per [0420] and as shown in Fig. 6, a fuel bypass pipe 1005 allows some of the fuel to avoid passing through trim heat exchanger 1006 and a valve although not shown may determine what proportion of the fuel passes through a first portion of the flowline through trim heat exchanger 1006 and what proportion passes through bypass pipe 1005; the valve is necessarily coupled to the flowline to determine proportion of fuel flow; also per [0503] one or more bypass pipes such as shown in Fig. 6 may be provided in various implementations). Controlling the fuel flow by recirculation through and/or bypassing of one or more heat exchangers can assist in heat management such as influencing fuel temperature on entry to the combustor 16 or pump 1003, or amount of heat transferred to the fuel per [0425]. The system of Fig. 7C may be modified to have a valve and bypass pipe coupled to the flowline to allow some fuel to bypass and not flow through trim heat exchanger 1006.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the system of Fig. 7C of Minelli to include a valve coupled to the flowline to control a flow rate of the fuel in the first portion of the flowline as further taught by Minelli to enable via the valve proportioning a flow of fuel through the first portion of the flowline and the trim heat exchanger and enable via the valve proportioning a flow of fuel through the bypass pipe to avoid passing through the trim heat exchanger to assist in heat management such as influencing fuel temperature on entry to the combustor or fuel pump, or amount of heat transferred to the fuel.
Minelli does not explicitly teach the waste heat recovery heat exchanger positioned in an exhaust section of the gas turbine engine, the fuel to absorb the second heat in the waste heat recovery heat exchanger from core exhaust waste heat.
Brady teaches with reference to Figs. 2-3, a gas turbine engine (100) with a waste heat recovery heat exchanger (labeled in annotated Fig. 3) positioned in an exhaust section (128 Fig. 3) of the gas turbine engine (waste heat recovery heat exchanger is positioned in exhaust section 128 in annotated Fig. 3), a fuel to absorb heat in the waste heat recovery heat exchanger from core exhaust waste heat ([0053] describes conduit(s) 302 carrying fuel can be positioned in the outer casing 118 in FIG. 2 of the gas turbine 100 and can form loops that are positioned at least partially around a perimeter of the exhaust section 128 that enables the thermal energy from the combustion gases 160, i.e., core exhaust waste heat, to heat the fuel in preparation for combustion, i.e., the fuel absorbs heat in the waste heat recovery heat exchanger).
Minelli modified in view of Brady has waste heat recovery heat exchanger 7010 include loops carrying fuel that are positioned at least partially around a perimeter of the exhaust section in the outer casing of the exhaust section such that the outer casing, i.e., turbine case, is cooled by the fuel while the fuel absorbs second heat transferred from the core exhaust waste heat via the turbine case cooling system components in the exhaust section.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the invention of Minelli such that the waste heat recovery heat exchanger is positioned in an exhaust section of the gas turbine engine, the fuel to absorb the second heat in the waste heat recovery heat exchanger from core exhaust waste heat as taught by Brady to cool the outer casing of the exhaust section while heating the fuel in preparation for combustion.
Regarding claim 22, Minelli in view of Brady teaches all that is claimed above and teaches the first portion of the flowline is positioned upstream of the second portion (in annotated Fig. 7C of Minelli, first portion of flowline is positioned upstream of second portion with respect to fuel flow direction towards combustor 16 as shown by flow arrows).
Regarding claim 27, Minelli in view of Brady teaches all that is claimed above and Minelli further teaches a bypass valve (7011 Fig. 7C) coupled to the flowline upstream of the second portion of the flowline (7011 is coupled to flowline upstream of second portion of the flowline) to enable a first portion of the fuel to bypass the waste heat recovery heat exchanger and mix with a second portion of the fuel that passed through the waste heat recovery heat exchanger downstream of the waste heat recovery heat exchanger (per para. 0428, at least a portion of the fuel exiting heat exchanger 1004 may be returned to the main fuel flowline without passing through waste heat recovery heat exchanger 7010—the proportion directed to 7010 may be adjusted based on need and controlled with bypass valve 7011; first portion of the fuel bypassing 7010 via bypass valve 7011 is able to mix with second portion of the fuel which has passed through 7010 downstream of 7010 as shown in annotated Fig. 7C), and wherein the first portion of the fuel is to absorb the portion of the second heat from the second portion of the fuel (first portion of the fuel has only been heated in 1006 and 1004 while second portion of fuel which has passed through 7010 additionally absorbs second heat such that when the first portion of the fuel flows from 7011 into the flowline downstream of 7010 the first portion of the fuel absorbs the portion of the second heat from the second portion of the fuel flowing from 7010).
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Regarding claim 28, Minelli in view of Brady teaches all that is claimed above and teaches when the fuel bypasses the waste heat recovery heat exchanger, the valve blocks the fuel from flowing through the first portion of the flowline and absorbing the first heat in the trim heat exchanger (intended use but Minelli in view of Brady is capable of this limitation since the position of the valve and the position of the bypass valve are each controllable such that the valve may be positioned to bypass flow and block fuel from flowing through the first portion of the flowline to avoid flow through the first trim heat exchanger 1006 which in turn avoids absorbing first heat at the same time as the bypass valve 7011 is positioned to have the fuel bypass the waste heat recovery heat exchanger 7010).
Regarding claim 41, Minelli in view of Brady teaches all that is claimed above and Minelli further teaches the system includes fuel temperature controlling circuitry ([0506] describes controller 58 is used to actively manage fuel and/or oil flows through and around the heat exchangers 1004, 1006, 2020 and controller 58 may be a part of, or provided by, an EEC, or may be a separate unit; 58 may receive inputs from one or more temperature sensors 1009, and may control one or more valves, and/or the pump 1003, based on the received data and one or more oil feed pumps and/or scavenge pumps may also be controlled by the controller) configured to:
cause the valve to block the fuel from flowing through the first portion of the flowline and absorb the first heat in the trim heat exchanger during first operations (per [0507] fuel flow may be controlled by using one or more bypass pipes 1005 arranged to allow a proportion of the fuel to avoid passing through either or both heat exchangers, i.e., the valve is caused to bypass and block the fuel from flowing through the first portion of the flowline flow to first trim heat exchanger 1006 during first engine operations when 58 receives data indicating less heating of the fuel is needed);
cause the valve to enable the fuel to flow through the first portion of the flowline and absorb the first heat in the trim heat exchanger during second operations different than the first operations (per [0507] fuel flow may be controlled by using one or more bypass pipes 1005 arranged to allow a proportion of the fuel to avoid passing through either or both heat exchangers and/or by adjusting the split in % fuel which flows straight to the combustor 16 from the primary fuel-oil heat exchanger 1006 as opposed to % fuel which flows from the primary fuel-oil heat exchanger into the secondary fuel-oil heat exchanger 1004 and optionally then back to re-join the fuel flowing into the combustor 16, i.e., the valve is caused to enable at least a third portion of the fuel not bypassed to flow to the first trim heat exchanger 1006 during second engine operations when 58 receives data indicating more heating of the fuel is needed; second engine operations when more heating of the fuel is needed is different than first engine operations when less heating of the fuel is needed);
cause the bypass valve to block the fuel from bypassing the waste heat recovery heat exchanger during the second operations (when 58 determines fuel is needed for waste heat recovery heat exchanger 7010 and fuel is not needed to be returned straight to the main fuel flow path/combustor 16, i.e., 58 causes bypass valve 7011 to control the proportions of fuel accordingly such that 7011 blocks the fuel from bypassing 7010 during second engine operations when 58 receives data indicating more heating of the fuel is needed); and
cause the bypass valve to enable the fuel to bypass the waste heat recovery heat exchanger during the first operations (per [0428] any fuel not needed for waste heat recovery heat exchanger 7010 may be returned straight to the main fuel flow path/combustor 16, i.e., causes bypass valve 7011 to enable the fuel to bypass 7010 to be returned straight to combustor 16 during first engine operations when 58 receives data indicating less heating of the fuel is needed).
Claim(s) 29-30, 36-38 and 44 is/are rejected under 35 U.S.C. 103 as being unpatentable over Minelli et al. 20250198338.
Regarding independent claim 29, Minelli teaches a system comprising:
a flowline (labeled in annotated Fig. 7C);
a fuel tank (50 Fig. 7C; para. 0428) coupled to a first end (labeled in annotated Fig. 7C) of the flowline;
a combustor (16 Fig. 7C; para. 0428) coupled to a second end (labeled in annotated Fig. 7C) of the flowline, the flowline to carry fuel from the fuel tank to the combustor (intended use but flowline in Fig. 7C is for carrying fuel from 50 to 16 per para. 0417 which describes first embodiment of Fig. 6 with Fig. 7C having some similar components);
a first trim heat exchanger (1006 Fig. 7C) coupled to a first portion of the flowline (labeled in annotated Fig. 7C; 1006 is coupled to first portion of flowline), the fuel to absorb first heat in the first trim heat exchanger (first heat from oil is transferred to the fuel in 1006 per para. 0419);
a waste heat recovery heat exchanger (7010 Fig. 7C) coupled to a second portion of the flowline (labeled in annotated Fig. 7C; 7010 is coupled to second portion of flowline), the fuel to absorb second heat in the waste heat recovery heat exchanger (per para. 0427, 7010 may include turbine case cooling (TCC) systems in which the fuel absorbs second heat from turbine case cooling system components, such that 7010 recovers waste heat from the turbine case cooling system components by transferring the second heat to the fuel); and
a bypass valve (7011 Fig. 7C) coupled to a fourth portion of the flowline (labeled in annotated Fig. 7C) upstream of the waste heat recovery heat exchanger (fourth portion of flowline is upstream of 7010 in annotated Fig. 7C with respect to fuel flow direction towards combustor 16 as shown by flow arrows) to control a flow rate of the fuel that bypasses the waste heat recovery heat exchanger (per para. 0428, at least a portion of the fuel exiting heat exchanger 1004 may be returned to the main fuel flowline without passing through waste heat recovery heat exchanger 7010—the proportion directed to 7010 may be adjusted based on need and controlled with bypass valve 7011), the bypass valve to cause a portion of the second heat to be absorbed from the fuel (bypass valve 7011 may send a proportion of fuel to the waste heat recovery heat exchanger 7010 and may bypass another proportion of fuel, the fuel having second heat subsequently flowing from waste heat recovery heat exchanger 7010 and re-joining with fuel which has bypassed 7010 and therefore has not been further heated in 7010, such that the bypassed fuel absorbs a portion of the second heat from the fuel coming from 7010).
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Minelli does not explicitly teach in Fig. 7C a valve coupled to the flowline to control a flow rate of the fuel in the first portion of the flowline, and
wherein the valve blocks the fuel from entering the first portion of the flowline when the bypass valve causes the portion of the second heat to be absorbed from the fuel.
Minelli further teaches in Fig. 6 a valve coupled to a flowline to control a flow rate of the fuel in a first portion of the flowline (per [0420] and as shown in Fig. 6, a fuel bypass pipe 1005 allows some of the fuel to avoid passing through trim heat exchanger 1006 and a valve although not shown may determine what proportion of the fuel passes through a first portion of the flowline through trim heat exchanger 1006 and what proportion passes through bypass pipe 1005; the valve is necessarily coupled to the flowline to determine proportion of fuel flow; also per [0503] one or more bypass pipes such as shown in Fig. 6 may be provided in various implementations). Controlling the fuel flow by recirculation through and/or bypassing of one or more heat exchangers can assist in heat management such as influencing fuel temperature on entry to the combustor 16 or pump 1003, or amount of heat transferred to the fuel per [0425]. The system of Fig. 7C may be modified to have a valve and bypass pipe coupled to the flowline to allow some fuel to bypass and not flow through first trim heat exchanger 1006.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the system of Fig. 7C of Minelli to include a valve coupled to the flowline to control a flow rate of the fuel in the first portion of the flowline as further taught by Minelli to enable via the valve proportioning a flow of fuel through the first portion of the flowline and the first trim heat exchanger and enable via the valve proportioning a flow of fuel through the bypass pipe to avoid passing through the first trim heat exchanger to assist in heat management such as influencing fuel temperature on entry to the combustor or fuel pump, or amount of heat transferred to the fuel.
In addition, the modified invention of Minelli is capable of having the valve block the fuel from entering the first portion of the flowline when the bypass valve causes the portion of the second heat to be absorbed from the fuel as claimed, since the position of the valve and the position of the bypass valve are each controllable such that the valve may be positioned to bypass flow and block fuel from entering the first portion of the flowline to avoid flow through the first trim heat exchanger at the same time as the bypass valve is positioned to have some fuel bypass the waste heat recovery heat exchanger and cause the portion of the second heat to be absorbed from the fuel.
Regarding claim 30, Minelli further teaches the first trim heat exchanger is positioned upstream of the waste heat recovery heat exchanger (1006 is upstream of 7010 in Fig. 7C).
Regarding independent claim 36, as best understood, Minelli teaches a system comprising:
a flowline (labeled in annotated Fig. 7C);
a fuel tank (50 Fig. 7C; para. 0428) coupled to a first end (labeled in annotated Fig. 7C) of the flowline;
a combustor (16 Fig. 7C; para. 0428) coupled to a second end (labeled in annotated Fig. 7C) of the flowline, the flowline to carry fuel from the fuel tank to the combustor (intended use but flowline in Fig. 7C is for carrying fuel from 50 to 16 per para. 0417 which describes first embodiment of Fig. 6 with Fig. 7C having some similar components);
a first trim heat exchanger (1006 Fig. 7C) coupled to the flowline (1006 is coupled to the flowline in annotated Fig. 7C), the fuel to absorb first heat in the first trim heat exchanger (first heat from oil is transferred to the fuel in 1006 per para. 0419);
a waste heat recovery heat exchanger (7010 Fig. 7C) coupled to the flowline (7010 is coupled to the flowline in Fig. 7C), the fuel to absorb second heat in the waste heat recovery heat exchanger (per para. 0427, 7010 may include turbine case cooling (TCC) systems in which the fuel absorbs second heat from turbine case cooling system components, such that 7010 recovers waste heat from the turbine case cooling system components by transferring the second heat to the fuel);
a second valve (7011 Fig. 7C) coupled to the flowline, wherein a position of the second valve controls whether a portion of the second heat is absorbed from the fuel (per para. 0428, at least a portion of the fuel exiting heat exchanger 1004 may be returned to the main fuel flowline without passing through waste heat recovery heat exchanger 7010 and the proportion directed to 7010 may be adjusted based on need and controlled with second valve 7011; a position of the second valve 7011 may send a proportion of fuel to the waste heat recovery heat exchanger 7010 and may bypass another proportion of fuel, the proportion of fuel having second heat subsequently flowing from waste heat recovery heat exchanger 7010 re-joins with the proportion of fuel which has bypassed 7010 and therefore has not been further heated in 7010, such that the bypassed fuel absorbs a portion of the second heat from the proportion of fuel coming from 7010),
wherein at least a first portion of the fuel flows to the waste heat recovery heat exchanger throughout first engine operations and second engine operations (per [0428] the proportion of fuel directed to 7010 may be adjusted based on need and controlled by second valve 7011, such that at least a first portion of the fuel flows to 7010 throughout first engine operations and second engine operations); and
fuel temperature controlling circuitry ([0506] describes controller 58 is used to actively manage fuel and/or oil flows through and around the heat exchangers 1004, 1006, 2020 and controller 58 may be a part of, or provided by, an EEC, or may be a separate unit; 58 may receive inputs from one or more temperature sensors 1009, and may control one or more valves, and/or the pump 1003, based on the received data and one or more oil feed pumps and/or scavenge pumps may also be controlled by the controller) configured to:
wherein the second valve causes a second portion of the fuel to bypass the waste heat recovery heat exchanger during the first engine operations (per [0428] any fuel not needed for waste heat recovery heat exchanger 7010 may be returned straight to the main fuel flow path/combustor 16, i.e., second valve 7011 causes a second portion of the fuel to bypass 7010 to be returned straight to combustor 16 during first engine operations when 58 receives data indicating less heating of the fuel is needed); and
cause the second valve to block the fuel from flowing to a portion of the flowline in which the portion of the second heat is absorbed from the fuel during the second engine operations (see 112(b): interpreted as cause the second valve to block the second portion of the fuel from flowing to a portion of the flowline to prevent the portion of the second heat being absorbed from the first portion of fuel during the second engine operations: when 58 determines fuel is needed for waste heat recovery heat exchanger 7010 and fuel is not needed to be returned straight to the main fuel flow path/combustor 16, i.e., during second engine operations when 58 receives data indicating more heating of the fuel is needed, 58 causes second valve 7011 to control the proportions of fuel accordingly such that 7011 blocks the second portion of the fuel flowing to a portion of the flowline labeled in annotated Fig. 7C which prevents the portion of second heat from being absorbed from the first portion of the fuel from 7010 during the second engine operations).
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Minelli does not explicitly teach in Fig. 7C a first valve coupled to the flowline, wherein a position of the first valve controls whether the fuel absorbs the first heat in the first trim heat exchanger; the fuel temperature controlling circuitry configured to: cause the first valve to block the fuel from flowing to the first trim heat exchanger during the first engine operations; and wherein the first valve causes at least a third portion of the fuel to flow to the first trim heat exchanger during the second engine operations.
Minelli further teaches in Fig. 6 a first valve coupled to the flowline (per [0420] and as shown in Fig. 6, a fuel bypass pipe 1005 allows some of the fuel to avoid passing through trim heat exchanger 1006 and a valve although not shown may determine what proportion of the fuel passes through a first portion of the flowline through trim heat exchanger 1006 and what proportion passes through bypass pipe 1005; the valve is necessarily coupled to the flowline to determine proportion of fuel flow; also per [0503] one or more bypass pipes such as shown in Fig. 6 may be provided in various implementations), wherein a position of the first valve controls whether the fuel absorbs the first heat in the first trim heat exchanger (per [0420] first valve determines what proportion of the fuel passes through trim heat exchanger 1006 and accordingly absorbs first heat and first valve determines what proportion passes through bypass pipe 1005).
Controlling the fuel flow by recirculation through and/or bypassing of one or more heat exchangers can assist in heat management such as influencing fuel temperature on entry to the combustor 16 or pump 1003, or amount of heat transferred to the fuel per [0425]. The system of Fig. 7C may be modified to have a valve and bypass pipe coupled to the flowline to allow some fuel to bypass and not flow through first trim heat exchanger 1006.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the system of Fig. 7C of Minelli to include a first valve coupled to the flowline, wherein a position of the first valve controls whether the fuel absorbs the first heat in the first trim heat exchanger as further taught by Minelli to enable via the valve proportioning a flow of fuel through the first trim heat exchanger and enable via the first valve proportioning a flow of fuel through the bypass pipe to avoid passing through the first trim heat exchanger to assist in heat management such as influencing fuel temperature on entry to the combustor or fuel pump, or amount of heat transferred to the fuel.
As modified, Minelli further teaches
the fuel temperature controlling circuitry configured to:
cause the first valve to block the fuel from flowing to the first trim heat exchanger during the first engine operations (per [0507] fuel flow may be controlled by using one or more bypass pipes 1005 arranged to allow a proportion of the fuel to avoid passing through either or both heat exchangers, i.e., first valve is caused to bypass and block fuel flow to first trim heat exchanger 1006, during first engine operations when 58 receives data indicating less heating of the fuel is needed); and
wherein the first valve causes at least a third portion of the fuel to flow to the first trim heat exchanger during the second engine operations (per [0507] fuel flow may be controlled by using one or more bypass pipes 1005 arranged to allow a proportion of the fuel to avoid passing through either or both heat exchangers and/or by adjusting the split in % fuel which flows straight to the combustor 16 from the primary fuel-oil heat exchanger 1006 as opposed to % fuel which flows from the primary fuel-oil heat exchanger into the secondary fuel-oil heat exchanger 1004 and optionally then back to re-join the fuel flowing into the combustor 16, i.e., the first valve causes at least a third portion of the fuel not bypassed to flow to the first trim heat exchanger 1006 during second engine operations when 58 receives data indicating more heating of the fuel is needed).
Regarding claim 37, Minelli further teaches the second valve is coupled to a branch section (labeled in annotated Fig. 7C; branch section is coupled to second valve 7011 in annotated Fig. 7C) of the flowline that enables a portion of the fuel to bypass the waste heat recovery heat exchanger (a portion of fuel flowing from bypass valve 7011 is able to bypass 7010 via branch section in annotated Fig. 7C).
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Regarding claim 38, as best understood, Minelli further teaches the portion of the fuel is a first portion further including a mixer to mix the first portion of the fuel with a second portion of the fuel that passed through the waste heat recovery (see 112(b): interpreted as: further including a mixer to mix the second portion of the fuel that bypasses the waste heat recovery heat exchanger with the first portion of the fuel that passed through the waste heat recovery: mixer is labeled in annotated Fig. 7C at junction of branch section and section extending from 7010 to 16; at least para. 0030 describes fuel from one branch re-joining, i.e., mixing with, fuel from another branch or path).
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Regarding claim 44, Minelli teaches the fuel temperature controlling circuitry is configured to cause the second valve to block the fuel from bypassing the waste heat recovery heat exchanger during the second engine operations (as discussed above in claim 36, when 58 determines fuel is needed for waste heat recovery heat exchanger 7010 and fuel is not needed to be returned straight to the main fuel flow path/combustor 16, i.e., during second engine operations, 58 causes second valve 7011 to control the proportions of fuel accordingly such that 7011 allows fuel to flow to 7010 and blocks fuel from bypassing 7010).
Claim(s) 42-43 is/are rejected under 35 U.S.C. 103 as being unpatentable over Minelli et al. 20250198338 in view of Brady 20230358180.
Regarding claims 42 and 43, Minelli teaches all that is claimed above respectively in claims 29 and 36, and further teaches the system includes a gas turbine engine (Fig. 1) including the combustor 16, a turbine section (17, 19 in Fig. 1) downstream of the combustor (17,19 are downstream of 16), and an exhaust section (20 Fig. 1) downstream of the turbine section (20 is downstream of 17, 19).
Minelli does not explicitly teach wherein the waste heat recovery heat exchanger is positioned in the exhaust section of the gas turbine engine to cause the fuel to absorb the second heat from core exhaust waste heat in the exhaust section.
Brady teaches with reference to Figs. 2-3, a gas turbine engine (100) with a waste heat recovery heat exchanger (labeled in annotated Fig. 3) positioned in an exhaust section (128 Fig. 3) of the gas turbine engine (waste heat recovery heat exchanger is positioned in exhaust section 128 in annotated Fig. 3), a fuel to absorb heat in the waste heat recovery heat exchanger from core exhaust waste heat ([0053] describes conduit(s) 302 carrying fuel can be positioned in the outer casing 118 in FIG. 2 of the gas turbine 100 and can form loops that are positioned at least partially around a perimeter of the exhaust section 128 that enables the thermal energy from the combustion gases 160, i.e., core exhaust waste heat, to heat the fuel in preparation for combustion, i.e., the fuel absorbs heat in the waste heat recovery heat exchanger).
Minelli modified in view of Brady has waste heat recovery heat exchanger 7010 include loops carrying fuel that are positioned at least partially around a perimeter of the exhaust section in the outer casing of the exhaust section such that the outer casing, i.e., turbine case, is cooled by the fuel while the fuel absorbs second heat transferred from the core exhaust waste heat via the turbine case cooling system components in the exhaust section.
It would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the invention of Minelli such that the waste heat recovery heat exchanger is positioned in an exhaust section of the gas turbine engine, the fuel to absorb the second heat in the waste heat recovery heat exchanger from core exhaust waste heat as taught by Brady to cool the outer casing of the exhaust section while heating the fuel in preparation for combustion.
Response to Arguments
On page 9 of Remarks under Claim Objections, Applicant traverses the claim objections but also states that claims 22 and 29 have been amended. However, claims 22 and 29 have not been amended such that the claim objections remain.
Regarding Applicant’s footnote 1 on page 9 of Remarks about prior art of record Minelli et al. 20250198338, Minelli et al. 20250198338 does qualify as prior art under 35 U.S.C. § 102(a)(2) since it has effective filing date Dec. 14, 2023 from priority to foreign application GB 2319125.7.
Applicant’s arguments with respect to independent claim(s) 21, 29 and 36 have been considered but are moot because the new grounds of rejection rely on new prior art of record Brady 20230358180 in a 102 rejection of claim 21 as Brady teaches the new limitations added to claim 21 regarding the waste heat recovery heat exchanger, a 103 rejection of claim 29 is currently over Minelli using Fig. 7C as the base reference in view of Fig. 6 in light of new claim 42 depending from claim 29 requiring positioning of the waste heat recovery heat exchanger in the exhaust section such that a 103 rejection of claim 42 is over Minelli in view of Brady, and a 103 rejection of claim 36 as best understood is over Minelli Fig. 7C in view of Fig. 6 in the current rejections described 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.
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/A.J.H./ Examiner, Art Unit 3741
/LORNE E MEADE/Primary Examiner, Art Unit 3741