DETAILED ACTION
This is in response to the Request for Continued Examination filed 2/4/2026 wherein claims 4-5, 9-10, 13, 17, and 19 are canceled, and claims 1-3, 6-8, 11-12, 14-16, 18, and 20 are presented for examination.
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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 2/4/2026 has been entered.
Claim Rejections - 35 USC § 103
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 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.
Claims 1 and 6-8 are rejected under 35 U.S.C. 103 as being unpatentable over Staubach et al. (US 2021/0300575) in view of Boucher et al. (US 2021/0340908) and Sen et al. (US 2019/0249599).
Regarding Independent Claim 1, Staubach teaches (Figures 1-6) an aircraft propulsion system (see Figures 4-6) comprising:
a core engine (432) comprising a main compressor where an inlet airflow is compressed and communicated to a combustor to generate an exhaust gas flow that is expanded through a main turbine section to generate shaft power used to drive the main compressor and a propulsive fan (see Paragraph 0049 and Figure 4);
a fuel cell (404) generating electric power from a flow of fuel (410) and oxygen (406) and emitting a fuel cell exhaust flow containing water (414); and
a cryogenic fuel system (from 402 to 404 and 432; see Figure 4 and Paragraph 0047) comprising a cryogenic fuel storage tank (402; see Figure 4 and Paragraph 0047), a fuel flow path (410) for routing a cryogenic fuel flow to the combustor of the core engine (at 432; see Figure 4).
Staubach also teaches an electric motor (206) that is driven by electric power (210) from a generator (208) and mechanically coupled (see Figure 2) to drive the propulsive fan (202) through an engine shaft (204).
Staubach’s embodiment in Figure 4 does not teach a bottoming cycle where a working fluid is heated and expanded through a bottom turbine to generate shaft power driving an output shaft; a generator driven by the output shaft to generate electric power; an electric motor driven by electric power from the generator and mechanically coupled to drive the propulsive fan through an engine shaft; a first heat exchanger providing thermal communication between the fuel cell exhaust flow and the working fluid of the bottoming cycle; a fuel/working fluid heat exchanger for cooling the working fluid with the cryogenic fuel flow, and a second heat exchanger where the cryogenic fuel flow is heated by the exhaust gas flow from the core engine prior to being injected into the combustor, wherein a portion of the cryogenic fuel heated in the second heat exchanger is communicated to the fuel cell.
Staubach’s Figure 5 embodiment does teach, however, a bottoming cycle (518; see Figure 5 and Paragraph 0054) where a working fluid (520) is heated and expanded through a bottom turbine (526) to generate shaft power (528); a first heat exchanger (512) providing thermal communication between the fuel cell exhaust flow (from 504) and the working fluid (520) of the bottoming cycle (518); and a fuel/working fluid heat exchanger (530) for cooling (see Paragraph 0055) the working fluid (520) with the cryogenic fuel flow (510).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach’s Figure 4 embodiment to include a bottoming cycle where a working fluid is heated and expanded through a bottom turbine to generate shaft power, a first heat exchanger providing thermal communication between the fuel cell exhaust flow and the working fluid of the bottoming cycle, and a fuel/working fluid heat exchanger for cooling the working fluid with the cryogenic fuel flow, as taught by Staubach’s Figure 5 embodiment, in order to generate work through the use of a working fluid within a waste heat recovery system (Paragraphs 0054-0056 of Staubach). Although Staubach teaches (Figure 4) that fuel from the storage tank (402) is delivered to the fuel cell (404) via an expansion turbine (418), Staubach does not teach a second heat exchanger where the cryogenic fuel flow is heated by the exhaust gas flow from the core engine prior to being injected into the combustor, wherein a portion of the cryogenic fuel heated in the second heat exchanger is communicated to the fuel cell, or that the bottom turbine generates shaft power to drive an output shaft; a generator driven by the output shaft to generate electric power; an electric motor driven by electric power from the generator and mechanically coupled to drive the propulsive fan through an engine shaft.
Boucher teaches (Figures 1-4) a second heat exchanger (332) where the cryogenic fuel flow (from 332) is heated by the exhaust gas flow (C, downstream from the combustor; see Figure 3 and Paragraph 0044) from the core engine (flow exiting 316) prior to being injected into the combustor (312), wherein a portion of the cryogeneic fuel (326) heated in the second heat exchanger (332) is communicated to an expansion turbine (334).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach to have a second heat exchanger where the cryogenic fuel flow is heated by the exhaust gas flow from the core engine prior to being injected into the combustor, wherein a portion of the cryogenic fuel heated in the second heat exchanger is communicated to the expansion turbine, as taught by Boucher, in order to allow the fuel to pick up heat from the exhaust of the turbine engine system so that the temperature of the cryogenic fuel will be increased (Paragraph 0039 of Boucher) and to have the heated fuel be expanded and drive a power shaft to generate power or drive mechanical operation of a component (see Paragraph 0045 of Boucher). As discussed above, Staubach teaches that the fuel cell is located downstream of the expansion turbine (see Figure 4 of Staubach).
Although Staubach also teaches an electric motor (206) that is driven by electric power (210) from a generator (208) and mechanically coupled (see Figure 2) to drive the propulsive fan (202) through an engine shaft (204), Staubach in view of Boucher does not teach that the power generated through the bottom turbine drives an output shaft, a generator driven by the output shaft to generate electric power, an electric motor driven by electric power from the generator and mechanically coupled to drive the propulsive fan through an engine shaft.
Sen teaches (Figures 1-6) power that is generated from a bottom turbine (108) being used to drive an output shaft (112), a generator (130) driven by the output shaft (112) to generate electric power (see Paragraph 0074), an electric motor (132) driven by electric power from the generator (130; see Paragraph 0075) and mechanically coupled to drive the propulsive fan (38) through an engine shaft (36; see Figures 3-6).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher to have the power generated through the bottom turbine drives an output shaft, a generator driven by the output shaft to generate electric power, an electric motor driven by electric power from the generator and mechanically coupled to drive the propulsive fan through an engine shaft, as taught by Sen, in order to allow for heat from the turbomachine to be extracted and converted to useful work by the closed cycle heat engine, and then provided back to the turbomachine so that the overall efficiency of the gas turbine engine is increased by converting the waste heat to useful work (see Paragraph 0075 of Sen).
Regarding Claim 6, Staubach in view of Boucher and Sen teaches the invention as claimed and as discussed above. Staubach in view of Boucher and Sen does not teach, as discussed so far, wherein the bottoming cycle further comprises a bottoming compressor for pressurizing the working fluid prior to expansion through the bottoming turbine.
Staubach teaches (Figures 1-6) wherein the bottoming cycle (518) further comprises a bottoming compressor (522) for pressurizing the working fluid (520) prior to expansion through the bottoming turbine (526, see Figure 5 and Paragraph 0054).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher and Sen to include a bottoming cycle where a working fluid is heated and expanded through a bottom turbine to generate shaft power, a first heat exchanger providing thermal communication between the fuel cell exhaust flow and the working fluid of the bottoming cycle, and a fuel/working fluid heat exchanger for cooling the working fluid with the cryogenic fuel flow, wherein the bottoming cycle further comprises a bottoming compressor for pressurizing the working fluid prior to expansion through the bottoming turbine, as taught by Staubach’s Figure 5 embodiment, for the same reasons discussed above in claim 1.
Regarding Claim 7, Staubach in view of Boucher and Sen teaches the invention as claimed and as discussed above. Staubach in view of Boucher and Sen does not teach, as discussed so far, wherein the bottoming cycle further comprises a recuperation heat exchanger where a pressurized portion of the working fluid from the bottoming compressor is heated by an expanded portion of the working fluid from the bottoming turbine.
Staubach further teaches (Figures 1-6) wherein the bottoming cycle (518) further comprises a recuperation heat exchanger (524) where a pressurized portion of the working fluid (520 exiting 522) from the bottoming compressor (522) is heated by an expanded portion of the working fluid (520 exiting 526) from the bottoming turbine (526).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher and Sen to include a bottoming cycle where a working fluid is heated and expanded through a bottom turbine to generate shaft power, a first heat exchanger providing thermal communication between the fuel cell exhaust flow and the working fluid of the bottoming cycle, and a fuel/working fluid heat exchanger for cooling the working fluid with the cryogenic fuel flow, wherein the bottoming cycle further comprises a bottoming compressor for pressurizing the working fluid prior to expansion through the bottoming turbine, wherein the bottoming cycle further comprises a recuperation heat exchanger where a pressurized portion of the working fluid from the bottoming compressor is heated by an expanded portion of the working fluid from the bottoming turbine, as taught by Staubach’s Figure 5 embodiment, for the same reasons discussed above in claim 1.
Regarding Claim 8, Staubach in view of Boucher and Sen teaches the invention as claimed and as discussed above. Staubach in view of Boucher and Sen does not teach, as discussed so far, wherein the recuperation heat exchanger is disposed upstream of the first heat exchanger such that heat from the recuperation heat exchanger is communicated to the working fluid before heat from the first heat exchanger.
Staubach further teaches (Figures 1-6) wherein the recuperation heat exchanger (524) is disposed upstream (relative to a flow of working fluid 520) of the first heat exchanger (512) such that heat from the recuperation heat exchanger (524) is communicated to the working fluid (520) before (see Figure 5) heat from the first heat exchanger (512).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher and Sen to include a bottoming cycle where a working fluid is heated and expanded through a bottom turbine to generate shaft power, a first heat exchanger providing thermal communication between the fuel cell exhaust flow and the working fluid of the bottoming cycle, and a fuel/working fluid heat exchanger for cooling the working fluid with the cryogenic fuel flow, wherein the bottoming cycle further comprises a bottoming compressor for pressurizing the working fluid prior to expansion through the bottoming turbine, wherein the bottoming cycle further comprises a recuperation heat exchanger where a pressurized portion of the working fluid from the bottoming compressor is heated by an expanded portion of the working fluid from the bottoming turbine, wherein the recuperation heat exchanger is disposed upstream of the first heat exchanger such that heat from the recuperation heat exchanger is communicated to the working fluid before heat from the first heat exchanger, as taught by Staubach’s Figure 5 embodiment, for the same reasons discussed above in claim 1.
Claims 2-3, 11-12, 14-16, 18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Staubach et al. (US 2021/0300575) in view of in view of Boucher et al. (US 2021/0340908) and Sen et al. (US 2019/0249599) as applied to claim 1 above, and further in view of Nickl et al. (DE 10 2020 107 905).
Regarding Claim 2, Staubach in view of Boucher and Sen teaches the invention as claimed and as discussed above. Staubach in view of Boucher and Sen does not teach an evaporator where water within the fuel cell exhaust flow is transformed into a steam flow for injection into the combustor of the core engine.
Nickl teaches (Figures 1-4) an evaporator (335) where water within the fuel cell exhaust flow (331) is transformed into a steam flow (325) for injection into the combustor (372) of the core engine (322).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher and Sen to include an evaporator where water within the fuel cell exhaust flow is transformed into a steam flow for injection into the combustor of the core engine, as taught by Nickl, in order to provide fluid for increasing the efficiency of the internal combustion engine and reduce the vehicle’s fuel consumption (Paragraphs 0018-0020 and 0047-0049 of Nickl).
Regarding Claim 3, Staubach in view of Boucher and Sen teaches the invention as claimed and as discussed above. Staubach in view of Boucher and Sen does not teach an intercooler system for cooling a core gas flow in the main compressor, wherein a portion of water from the fuel cell exhaust flow is communicated to the intercooling system.
Nickl teaches (Figures 1-4) an intercooler system (325 to 370) for cooling a core gas flow (342) in the main compressor (370), wherein a portion of water from the fuel cell exhaust flow (311, 324) is communicated to (see Figure 3) the intercooling system (325 to 370).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher and Sen to include an intercooler system for cooling a core gas flow in the main compressor, wherein a portion of water from the fuel cell exhaust flow is communicated to the intercooling system, as taught by Nickl, in order to provide fluid for increasing the efficiency of the internal combustion engine and reduce the vehicle’s fuel consumption (Paragraphs 0018-0020 and 0047-0049 of Nickl).
Regarding Independent Claim 11, Staubach teaches (Figures 1-6) a gas turbine assembly (see Figures 4-6) comprising:
a core engine (432) comprising a main compressor where an inlet airflow is compressed and communicated to a combustor to generate an exhaust gas flow that is expanded through a main turbine section to generate shaft power used to drive the main compressor and a propulsive fan (see Paragraph 0049 and Figure 4);
a fuel cell (404) generating electric power from a flow of fuel (410) and oxygen (406) and emitting a fuel cell exhaust flow containing water (414); and
a cryogenic fuel system (from 402 to 404 and 432; see Figure 4 and Paragraph 0047) comprising a cryogenic fuel storage tank (402; see Figure 4 and Paragraph 0047), a fuel flow path (410) for routing a cryogenic fuel flow to the combustor of the core engine (at 432; see Figure 4).
Staubach also teaches an electric motor (206) that is driven by electric power (210) from a generator (208) and mechanically coupled (see Figure 2) to drive the propulsive fan (202) through an engine shaft (204).
Staubach’s embodiment in Figure 4 does not teach a bottoming cycle where a working fluid is heated and expanded through a bottom turbine to generate shaft power driving an output shaft; a generator driven by the output shaft to generate electric power; an electric motor driven by electric power from the generator and mechanically coupled to drive the propulsive fan through an engine shaft; a first heat exchanger providing thermal communication between the fuel cell exhaust flow and the working fluid of the bottoming cycle; a fuel/working fluid heat exchanger for cooling the working fluid with the cryogenic fuel flow; and an evaporator where water within the fuel cell exhaust flow is transformed into a steam flow for injection into the combustor of the core engine; and a second heat exchanger where the cryogenic fuel flow is heated by the exhaust gas flow from the core engine prior to being injected into the combustor, wherein a portion of the cryogenic fuel heated in the second heat exchanger is communicated to the fuel cell.
Staubach’s Figure 5 embodiment does teach, however, a bottoming cycle (518; see Figure 5 and Paragraph 0054) where a working fluid (520) is heated and expanded through a bottom turbine (526) to generate shaft power (528); a first heat exchanger (512) providing thermal communication between the fuel cell exhaust flow (from 504) and the working fluid (520) of the bottoming cycle (518); and a fuel/working fluid heat exchanger (530) for cooling (see Paragraph 0055) the working fluid (520) with the cryogenic fuel flow (510).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach’s Figure 4 embodiment to include a bottoming cycle where a working fluid is heated and expanded through a bottom turbine to generate shaft power, a first heat exchanger providing thermal communication between the fuel cell exhaust flow and the working fluid of the bottoming cycle, and a fuel/working fluid heat exchanger for cooling the working fluid with the cryogenic fuel flow, as taught by Staubach’s Figure 5 embodiment, in order to generate work through the use of a working fluid within a waste heat recovery system (Paragraphs 0054-0056 of Staubach). Staubach does not teach an evaporator where water within the fuel cell exhaust flow is transformed into a steam flow for injection into the combustor of the core engine and a second heat exchanger where the cryogenic fuel flow is heated by the exhaust gas flow from the core engine prior to being injected into the combustor, wherein a portion of the cryogenic fuel heated in the second heat exchanger is communicated to the fuel cell, or that the bottom turbine generates shaft power to drive an output shaft; a generator driven by the output shaft to generate electric power; an electric motor driven by electric power from the generator and mechanically coupled to drive the propulsive fan through an engine shaft.
Boucher teaches (Figures 1-4) a second heat exchanger (332) where the cryogenic fuel flow (from 332) is heated by the exhaust gas flow (C, downstream from the combustor; see Figure 3 and Paragraph 0044) from the core engine (flow exiting 316) prior to being injected into the combustor (312), wherein a portion of the cryogeneic fuel (326) heated in the second heat exchanger (332) is communicated to an expansion turbine (334).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach to have a second heat exchanger where the cryogenic fuel flow is heated by the exhaust gas flow from the core engine prior to being injected into the combustor, wherein a portion of the cryogenic fuel heated in the second heat exchanger is communicated to the expansion turbine, as taught by Boucher, in order to allow the fuel to pick up heat from the exhaust of the turbine engine system so that the temperature of the cryogenic fuel will be increased (Paragraph 0039 of Boucher) and to have the heated fuel be expanded and drive a power shaft to generate power or drive mechanical operation of a component (see Paragraph 0045 of Boucher). As discussed above, Staubach teaches that the fuel cell is located downstream of the expansion turbine (see Figure 4 of Staubach). Staubach in view of Boucher does not teach an evaporator where water within the fuel cell exhaust flow is transformed into a steam flow for injection into the combustor of the core engine, or that the bottom turbine generates shaft power to drive an output shaft; a generator driven by the output shaft to generate electric power; an electric motor driven by electric power from the generator and mechanically coupled to drive the propulsive fan through an engine shaft.
Nickl teaches (Figures 1-4) an evaporator (335) where water within the fuel cell exhaust flow (331) is transformed into a steam flow (325) for injection into the combustor (372) of the core engine (322).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher to include an evaporator where water within the fuel cell exhaust flow is transformed into a steam flow for injection into the combustor of the core engine, as taught by Nickl, in order to provide fluid for increasing the efficiency of the internal combustion engine and reduce the vehicle’s fuel consumption (Paragraphs 0018-0020 and 0047-0049 of Nickl). Although Staubach also teaches an electric motor (206) that is driven by electric power (210) from a generator (208) and mechanically coupled (see Figure 2) to drive the propulsive fan (202) through an engine shaft (204), Staubach in view of Boucher and Nickl does not teach that the power generated through the bottom turbine drives an output shaft, a generator driven by the output shaft to generate electric power, an electric motor driven by electric power from the generator and mechanically coupled to drive the propulsive fan through an engine shaft.
Sen teaches (Figures 1-6) power that is generated from a bottom turbine (108) being used to drive an output shaft (112), a generator (130) driven by the output shaft (112) to generate electric power (see Paragraph 0074), an electric motor (132) driven by electric power from the generator (130; see Paragraph 0075) and mechanically coupled to drive the propulsive fan (38) through an engine shaft (36; see Figures 3-6).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher and Nickl to have the power generated through the bottom turbine drives an output shaft, a generator driven by the output shaft to generate electric power, an electric motor driven by electric power from the generator and mechanically coupled to drive the propulsive fan through an engine shaft, as taught by Sen, in order to allow for heat from the turbomachine to be extracted and converted to useful work by the closed cycle heat engine, and then provided back to the turbomachine so that the overall efficiency of the gas turbine engine is increased by converting the waste heat to useful work (see Paragraph 0075 of Sen).
Regarding Claim 12, Staubach in view of Boucher, Nickl, and Sen teaches the invention as claimed and as discussed above. Staubach in view of Boucher, Nickl, and Sen does not teach, as discussed so far, an intercooler system for cooling a core gas flow in the main compressor, wherein a portion of water from the fuel cell exhaust flow is communicated to the intercooling system.
Nickl teaches (Figures 1-4) an intercooler system (325 to 370) for cooling a core gas flow (342) in the main compressor (370), wherein a portion of water from the fuel cell exhaust flow (311, 324) is communicated to (see Figure 3) the intercooling system (325 to 370).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher, Nickl, and Sen to include an intercooler system for cooling a core gas flow in the main compressor, wherein a portion of water from the fuel cell exhaust flow is communicated to the intercooling system, as taught by Nickl, in order to provide fluid for increasing the efficiency of the internal combustion engine and reduce the vehicle’s fuel consumption (Paragraphs 0018-0020 and 0047-0049 of Nickl).
Regarding Claim 14, Staubach in view of Boucher, Nickl, and Sen teaches the invention as claimed and as discussed above. Staubach in view of Boucher, Nickl, and Sen does not teach, as discussed so far, wherein the bottoming cycle further comprises a bottoming compressor for pressurizing the working fluid prior to expansion through the bottoming turbine and a recuperation heat exchanger where a pressurized portion of the working fluid from the bottoming compressor is heated by an expanded portion of the working fluid from the bottoming turbine.
Staubach teaches (Figures 1-6) wherein the bottoming cycle (518) further comprises a bottoming compressor (522) for pressurizing the working fluid (520) prior to expansion through the bottoming turbine (526, see Figure 5 and Paragraph 0054), wherein the bottoming cycle (518) further comprises a recuperation heat exchanger (524) where a pressurized portion of the working fluid (520 exiting 522) from the bottoming compressor (522) is heated by an expanded portion of the working fluid (520 exiting 526) from the bottoming turbine (526).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher, Nickl, and Sen to include a bottoming cycle where a working fluid is heated and expanded through a bottom turbine to generate shaft power, a first heat exchanger providing thermal communication between the fuel cell exhaust flow and the working fluid of the bottoming cycle, and a fuel/working fluid heat exchanger for cooling the working fluid with the cryogenic fuel flow, wherein the bottoming cycle further comprises a bottoming compressor for pressurizing the working fluid prior to expansion through the bottoming turbine, wherein the bottoming cycle further comprises a recuperation heat exchanger where a pressurized portion of the working fluid from the bottoming compressor is heated by an expanded portion of the working fluid from the bottoming turbine, as taught by Staubach’s Figure 5 embodiment, for the reasons discussed above in claim 11.
Regarding Claim 15, Staubach in view of Boucher, Nickl, and Sen teaches the invention as claimed and as discussed above. Staubach in view of Boucher, Nickl, and Sen does not teach, as discussed so far, wherein the recuperation heat exchanger is disposed upstream of the first heat exchanger such that heat from the recuperation heat exchanger is communicated to the working fluid before heat from the first heat exchanger.
Staubach further teaches (Figures 1-6) wherein the recuperation heat exchanger (524) is disposed upstream (relative to a flow of working fluid 520) of the first heat exchanger (512) such that heat from the recuperation heat exchanger (524) is communicated to the working fluid (520) before (see Figure 5) heat from the first heat exchanger (512).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher, Nickl, and Sen to include a bottoming cycle where a working fluid is heated and expanded through a bottom turbine to generate shaft power, a first heat exchanger providing thermal communication between the fuel cell exhaust flow and the working fluid of the bottoming cycle, and a fuel/working fluid heat exchanger for cooling the working fluid with the cryogenic fuel flow, wherein the bottoming cycle further comprises a bottoming compressor for pressurizing the working fluid prior to expansion through the bottoming turbine, wherein the bottoming cycle further comprises a recuperation heat exchanger where a pressurized portion of the working fluid from the bottoming compressor is heated by an expanded portion of the working fluid from the bottoming turbine, wherein the recuperation heat exchanger is disposed upstream of the first heat exchanger such that heat from the recuperation heat exchanger is communicated to the working fluid before heat from the first heat exchanger, as taught by Staubach’s Figure 5 embodiment, for the same reasons discussed above in claim 11.
Regarding Claim 16, Staubach in view of Boucher, Nickl, and Sen teaches the invention as claimed and as discussed above. Staubach in view of Boucher, Nickl, and Sen does not teach, as discussed so far, further comprising an output shaft driven by the bottoming turbine for driving an accessory component.
Staubach teaches (Figures 1-6) an output shaft (the shaft connecting 522 and 526; see Figure 5) driven by the bottoming turbine (526). Staubach also teaches a power generation system (208) that can provide power (via 210) to a motor (206) to drive a fan (202).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher, Nickl, and Sen to generate work from the output driven by the bottoming turbine and to provide power to a motor to drive a fan, as taught by Staubach, in order to generate work by the turbine and to rotate a drive shaft to generate thrust (Paragraph 0039 of Staubach). It is further noted that a patent examiner may rely on "common knowledge and common sense of the person of ordinary skill in the art without any specific hint or suggestion in a particular reference") and In re Zurko, 258 F.3d 1379, 1383, 1385, 59 USPQ2d 1693 at 1695, 1697 (Fed. Cir. 2001). In this case, one having ordinary skill in the art before the effective filing date of the claimed invention to recognize that directing the work from the bottoming turbine to be utilized to drive a fan would have been logical in order to provide supplemental power used to drive a fan during takeoff or other high demand aircraft operations.
Regarding Independent Claim 18, Staubach teaches (Figures 1-6) a method of operating an aircraft propulsion system (see Figures 4-6) comprising:
generating an exhaust flow in a combustor of a core engine (432) by igniting a mixture of compressed air (see Paragraph 0002) and a cryogenic fuel (from 402); and
generating electric power in a fuel cell (404) from a flow of the cryogenic fuel (410) and oxygen (406) and emitting a fuel cell exhaust containing water (414).
Staubach also teaches providing power (210) to drive a propulsive fan (202) with an electric motor (206) coupled to (via 204) the propulsive fan (202) and driven by electric power (see Figure 2) generated by a generator (208).
Staubach’s embodiment in Figure 4 does not teach communicating thermal energy from the fuel cell exhaust into a working fluid within a bottoming cycle where a working fluid is heated and expanded through a bottom turbine to generate shaft power; generating electric power from a generator driven by an output shaft driven by the bottoming turbine; supplementing power to drive the propulsive fan with an electric motor coupled to the propulsive fan and driven by electric power generated by the generator; cooling the working fluid exhausted from the bottoming turbine in a fuel/working fluid heat exchanger where a cryogenic fuel accepts heat from the working fluid; and heating a portion of water contained in the fuel cell exhaust to generate a steam flow for injection into the combustor.
Staubach’s Figure 5 embodiment does teach, however, communicating thermal energy from the fuel cell exhaust (from 504) into a working fluid (520) within a bottoming cycle (518; see Figure 5 and Paragraph 0054) where a working fluid (520) is heated and expanded through a bottom turbine (526) to generate shaft power (528), cooling the working fluid (520) exhausted from the bottoming turbine (526) in a fuel/working fluid heat exchanger (530) where a cryogenic fuel (from 502) accepts heat (see Paragraph 0055) from the working fluid (520).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach’s Figure 4 embodiment to communicate thermal energy from the fuel cell exhaust into a working fluid within a bottoming cycle where a working fluid is heated and expanded through a bottom turbine to generate shaft power and cool the working fluid exhausted from the bottoming turbine in a fuel/working fluid heat exchanger where a cryogenic fuel accepts heat from the working fluid, as taught by Staubach’s Figure 5 embodiment, in order to generate work through the use of a working fluid within a waste heat recovery system (Paragraphs 0054-0056 of Staubach). Staubach teaches (Figure 4) that fuel from the storage tank (402) is delivered to the fuel cell (404) via an expansion turbine (418). Staubach does not teach heating a portion of water contained in the fuel cell exhaust to generate a steam flow for injection into the combustor, or heating the cryogenic fuel flow with a portion of the exhaust gas flow generated by the combustor and communicating the heated cryogenic fuel flow to the combustor and to the fuel cell; generating electric power from a generator driven by an output shaft driven by the bottoming turbine; or supplementing power to drive the propulsive fan with an electric motor coupled to the propulsive fan and driven by electric power generated by the generator.
Boucher teaches (Figures 1-4) heating the cryogenic fuel flow (from 332) with a portion of the exhaust gas flow (C, downstream from the combustor; see Figure 3 and Paragraph 0044) generated by the combustor (312) and communicating the heated cryogenic fuel flow (326, downstream of 332) to the combustor (312), wherein a portion of the cryogeneic fuel (326) heated in the second heat exchanger (332) is communicated to an expansion turbine (334).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Nickl to heating the cryogenic fuel flow with a portion of the exhaust gas flow generated by the combustor and communicating the heated cryogenic fuel flow to the combustor, as taught by Boucher, in order to allow the fuel to pick up heat from the exhaust of the turbine engine system so that the temperature of the cryogenic fuel will be increased (Paragraph 0039 of Boucher) and to have the heated fuel be expanded and drive a power shaft to generate power or drive mechanical operation of a component (see Paragraph 0045 of Boucher). As discussed above, Staubach teaches that the fuel cell is located downstream of the expansion turbine (see Figure 4 of Staubach). Staubach in view of Boucher does not teach heating a portion of water contained in the fuel cell exhaust to generate a steam flow for injection into the combustor, generating electric power from a generator driven by an output shaft driven by the bottoming turbine, or supplementing power to drive the propulsive fan with an electric motor coupled to the propulsive fan and driven by electric power generated by the generator.
Nickl teaches (Figures 1-4) heating (via 335) a portion of water contained in the fuel cell exhaust (311, 324) to generate a steam flow (325) for injection into the combustor (372).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher to include heating a portion of water contained in the fuel cell exhaust to generate a steam flow for injection into the combustor, as taught by Nickl, in order to provide fluid for increasing the efficiency of the internal combustion engine and reduce the vehicle’s fuel consumption (Paragraphs 0018-0020 and 0047-0049 of Nickl).
Although Staubach also teaches an electric motor (206) that is driven by electric power (210) from a generator (208) and mechanically coupled (see Figure 2) to drive the propulsive fan (202) through an engine shaft (204), Staubach in view of Boucher and Nickl does not teach generating electric power from a generator driven by an output shaft driven by the bottoming turbine, or supplementing power to drive the propulsive fan with an electric motor coupled to the propulsive fan and driven by electric power generated by the generator.
Sen teaches (Figures 1-6) generating electric power from a generator (130) driven by an output shaft (112) driven by a bottoming turbine (108) and supplementing power to drive a propulsive fan (38) with an electric motor (132) coupled to the propulsive fan (38) and driven by electric power generated (see Paragraphs 0074-0075) by the generator (130).
power that is generated from a bottom turbine (108) being used to drive an output shaft (112), a generator (130) driven by the output shaft (112) to generate electric power (see Paragraph 0074), an electric motor (132) driven by electric power from the generator (130; see Paragraph 0075) and mechanically coupled to drive the propulsive fan (38) through an engine shaft (36; see Figures 3-6).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher and Nickl to generate electric power from a generator driven by an output shaft driven by the bottoming turbine and supplement power to drive the propulsive fan with an electric motor coupled to the propulsive fan and driven by electric power generated by the generator, as taught by Sen, in order to allow for heat from the turbomachine to be extracted and converted to useful work by the closed cycle heat engine, and then provided back to the turbomachine so that the overall efficiency of the gas turbine engine is increased by converting the waste heat to useful work (see Paragraph 0075 of Sen).
Regarding Claim 20, Staubach in view of Boucher, Nickl, and Sen teaches the invention as claimed and as discussed above. Staubach in view of Boucher, Nickl, and Sen does not teach, as discussed so far, communicating a portion of water contained in the fuel cell exhaust for cooling a core flow through a compressor section of the core engine.
Nickl teaches (Figures 1-4) communicating a portion of water contained in the fuel cell exhaust (from 311, 324) for cooling a core flow (342) through a compressor section (370) of the core engine (322).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach in view of Boucher, Nickl, and Sen to include communicating a portion of water contained in the fuel cell exhaust for cooling a core flow through a compressor section of the core engine, as taught by Nickl, in order to provide fluid for increasing the efficiency of the internal combustion engine and reduce the vehicle’s fuel consumption (Paragraphs 0018-0020 and 0047-0049 of Nickl).
Response to Arguments
Applicant’s arguments with respect to claims 1-3, 6-8, 11-12, 14-16, 18, and 20 have been considered but are moot because the arguments do not apply to the new combination of references being used in this office action. However, to the extent possible, Applicant’s arguments have been addressed in the body of the rejection above, at the appropriate locations.
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/THOMAS P BURKE/Primary Examiner, Art Unit 3741