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 .
This is the third office action on the merits. This office action is in response to the request for continued examination filed on 12/15/2025. Applicant has amended claims 1, 10-12, and 20 and cancelled claims 8 and 19. Claims 1, 9-14, and 20 are pending and examined.
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 December 15, 2025 has been entered.
Priority
Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged. Applicant has not complied with one or more conditions for receiving the benefit of an earlier filing date under 35 U.S.C. 120 as follows:
The later-filed application must be an application for a patent for an invention which is also disclosed in the prior application (the parent or original nonprovisional application or provisional application). The disclosure of the invention in the parent application and in the later-filed application must be sufficient to comply with the requirements of 35 U.S.C. 112(a) or the first paragraph of pre-AIA 35 U.S.C. 112, except for the best mode requirement. See Transco Products, Inc. v. Performance Contracting, Inc., 38 F.3d 551, 32 USPQ2d 1077 (Fed. Cir. 1994).
The disclosure of the prior-filed application, Application No. 17/871,270, fails to provide adequate support or enablement in the manner provided by 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph for one or more claims of this application. Application 17/871,270 has no disclosure of “an intercooling heat exchanger where a first input of thermal energy from a core flow between stages in a compressor section of the core engine is communicated into the working fluid” and “a second heat exchanger configured to communicate additional input of thermal energy from the exhaust gas flow generated by the core engine into the flow of working fluid downstream from the first input of thermal energy from the intercooling heat exchanger” (claim 1, lines 8-13, and similarly for claim 12, lines 8-15). Accordingly, claims 1, 9-14, and 20 are not entitled to the benefit of the prior application filing date.
Claim Objections
Claims 1, 9-10, 12, and 20 are objected to because of the following informalities:
Claim 1, line 12: “the flow of working fluid” is believed to be in error for --a flow of the working fluid-- (see claim 1, line 4)
Claim 1, line 20: “a flow of the working fluid” should be changed to --the flow of the working fluid--, based on the above objection in claim 1, line 12
Claim 1, line 22: “an exhaust gas heat exchange” is believed to be in error for --an exhaust gas heat exchanger--
Claim 1, line 22-23: “the flow of cryogenic fuel” is believed to be in error for --the flow of the cryogenic fuel-- (see claim 1, lines 19-20)
Claim 1, line 23-24: “the flow of working fluid” is believed to be in error for --the flow of the working fluid--
Claim 9, lines 1: “The aircraft propulsion system as recited in claim 8” is believed to be in error for --The aircraft propulsion system as recited in claim 1-- (claim 8 has been cancelled)
Claim 10, line 3: “a flow of the working fluid” is believed to be in error for --the flow of the working fluid--
Claim 12, line 14: “between stages of the compressor” is believed to be in error for --between the stages of the compressor-- (see claim 12, line 9)
Claim 12, line 21: “the working fluid” (two instances) is believed to be in error for --the bottoming working fluid-- (see claim 12, lines 6-7)
Claim 12, line 23: “an exhaust gas heat exchange” is believed to be in error for --an exhaust gas heat exchanger--
Claim 12, line 23-24: “the flow of cryogenic fuel” is believed to be in error for --the flow of the cryogenic fuel-- (see claim 12, lines 20-21)
Claim 12, lines 24-25: “the flow of working fluid” is believed to be in error for --a flow of the bottoming working fluid-- (see claim 12, lines 6-7)
Claim 12, line 25: “the bottoming turbine section” is believed to be in error for --the bottoming turbine-- (see claim 12, line 6)
Claim 20, lines 4-5: “a turbine” is believed to be in error for --the turbine-- (see claim 12, line 2)
Appropriate correction is required.
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.
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.
Claims 1 and 10-14 are rejected under 35 U.S.C. 103 as being unpatentable over Staubach (US 11,506,124 B2), in view of Freund (US 2012/0159923 A1) and Pang (US 2014/0165572 A1).
Regarding claim 1, Staubach teaches (Fig. 9) an aircraft propulsion system (Fig. 9 shows a turbofan) comprising:
a core engine (900) comprising a combustor (914) where a cryogenic fuel (from 942 – see also col. 16, ll. 41-43: “the auxiliary cooling source 942 is a cold fuel tank (e.g., a cryogenic fuel tank)”) is mixed with compressed air (from 912) and ignited to generate an exhaust gas flow (arrow to the right of 918);
a bottoming cycle (902) where a working fluid (supercritical CO2 – see col. 17, ll. 16-17) is circulated within a closed circuit (path of 924 → 926 → 954 → 930 → 926 → 932 → 924 is a closed loop) comprising a bottoming compressor section (930) and a bottoming turbine section (924), wherein the working fluid is compressed in the bottoming compressor section (930) and expanded through the bottoming turbine section (924) to generate shaft power (934);
a first input of thermal energy (from the higher temperature of air after it is pressurized) from a core flow between stages in a compressor section (910 and 912) of the core engine (900) – (note that thermal energy from 910 is inputted into 912);
a second heat exchanger (932) configured to communicate additional input of thermal energy from the exhaust gas flow (from 918) generated by the core engine (900) into the flow of working fluid (from 926);
a cryogenic fuel system (940) comprising a cryogenic fuel storage tank (942 – col. 16, ll. 41-43), a fuel flow path for routing the cryogenic fuel (path of 942 → 954 → 956 → 960 → 914) to the combustor (914) of the core engine (900); and
a fuel/working fluid heat exchanger (954) providing thermal communication between a flow of the cryogenic fuel (from 942) and the working fluid (from 926) to cool a flow of the working fluid in the bottoming cycle (902).
However, Staubach does not teach an intercooling heat exchanger.
It is noted that Staubach’s second heat exchanger 932 would transfer a greater amount of thermal energy into the working fluid than an intercooling heat exchanger would transfer into the working fluid because Staubach’s second heat exchanger 932 is located in the exhaust gas flow path, where the temperature is much higher than the temperature of the core flow between stages in Staubach’s compressor section 910 and 912.
Freund teaches (Fig. 2) a similar system (100) comprising a core engine (10) and a bottoming cycle (110) where a working fluid (water/steam) is circulated;
an intercooling heat exchanger (50) where a first input of thermal energy from a core flow between stages in a compressor section (14 and 16) of the core engine (10) is communicated into the working fluid (water from 124);
a second heat exchanger (104) configured to communicate additional input of thermal energy from the exhaust gas flow (from 20) generated by the core engine (10) into the flow of working fluid (from 124 and 126) downstream (to the right) from the first input of thermal energy from the intercooling heat exchanger (50), wherein the second heat exchanger (104) is configured for transferring a greater amount of thermal energy into the working fluid than the first input of thermal energy from the intercooling heat exchanger (50) – (intended use, note that intercooling heat exchanger 50 heats water from 124 to produce feedwater 126, which is then fed into an evaporator or a superheater in second heat exchanger 104 – see ¶ [0041], ll. 8-12. In order to evaporate or superheat feedwater 126, the temperature of the exhaust gas must be higher than the temperature of feedwater 126. Therefore, second heat exchanger 104 transfers heat at a higher temperature than intercooling heat exchanger 50. Since water from 124 also goes into second heat exchanger 104, second heat exchanger 104 will transfer a greater amount of thermal energy to the water from 124 than intercooling heat exchanger 50 will transfer to the water from 124).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach by including an intercooling heat exchanger where the first input of thermal energy from the core flow between the stages in the compressor section of the core engine is communicated into the working fluid, in order to facilitate reducing the energy expended by the high-pressure compressor to compress the air to the desired operating pressures, thereby allowing a designer to increase the pressure ratio of the gas turbine engine which results in an increase in energy extracted from the gas turbine engine and a high net operating efficiency of the gas turbine engine, as taught by Freund (¶ [0031], ll. 14-23), therefore providing:
the second heat exchanger (Staubach, 932) configured to communicate the additional input of thermal energy from the exhaust gas flow generated by the core engine (Staubach, 900) into the flow of working fluid downstream from the first input of thermal energy from the intercooling heat exchanger (Freund, 50 – located at Staubach’s compressor section 910 and 912), wherein the second heat exchanger (932) is configured for transferring a greater amount of thermal energy into the working fluid than the first input of thermal energy from the intercooling heat exchanger (50) – (intended use and as discussed above in Freund).
However, Staubach, in view of Freund, does not teach an exhaust gas heat exchange downstream of the second heat exchanger where the flow of cryogenic fuel is placed in thermal communication with the exhaust gas flow after cooling the flow of working fluid exhausted from the bottoming turbine section before injection into the combustor.
It is noted that Staubach teaches a supplemental heat exchanger (960) downstream of the second heat exchanger (954) and before the combustor (914), wherein the supplemental heat exchanger (960) “can be arranged to provide additional cooling for fluids of the engine or aircraft” (col. 16, ll. 62-64).
Pang teaches (Fig. 1) a similar system comprising:
a core engine (104) comprising a combustor (105) where a fuel (“Fuel” above 112) is mixed with compressed air (“Air” below 103) and ignited to generate an exhaust gas flow (154);
a bottoming cycle (106) where a working fluid (steam/water) is circulated;
a second heat exchanger (138) configured to communicate additional input of thermal energy from the exhaust gas flow (154) generated by the core engine (104) into the flow of working fluid; and further teaches:
an exhaust gas heat exchange (comprising 114, 156, 158, and 160, which form a closed cycle) downstream of the second heat exchanger (138) where the flow of fuel is placed in thermal communication with the exhaust gas flow (154) – (160 is in direct thermal communication with the exhaust gas flow) before injection into the combustor (105).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach, in view of Freund, by including an exhaust gas heat exchange (in place of Staubach’s supplemental heat exchanger 960) downstream of the second heat exchanger where the flow of cryogenic fuel is placed in thermal communication with the exhaust gas flow before injection into the combustor, in order to further raise the temperature of the flow of cryogenic fuel to a level that is higher than the temperature of the cryogenic fuel flow at an outlet of the fuel/working fluid heat exchanger, thereby effectuating a rapid heating of the cryogenic fuel flow during a startup sequence of the gas turbine engine, as taught by Pang (¶ [0030], ll. 13-17 and ¶ [0031], ll. 1-3), therefore providing:
where the flow of cryogenic fuel (Staubach, from 942) is placed in thermal communication with the exhaust gas flow (Staubach, to the right of 918) after cooling the flow of working fluid exhausted from the bottoming turbine section (Staubauch, 924) before injection into the combustor (Staubach, 914).
Regarding claim 10, Staubach, in view of Freund and Pang, teaches the invention as claimed and as discussed above for claim 1, and Staubach further teaches (Fig. 9) the second heat exchanger (932) is in thermal communication with a flow of the working fluid (from line 138) flowing from the bottoming compressor (930) section to the bottoming turbine section (924).
However, Staubach, in view of Freund as discussed so far, does not teach the intercooling heat exchanger is in thermal communication with the flow of the working fluid flowing from the bottoming compressor section to the bottoming turbine section.
Freund further teaches (Fig. 2) the bottoming cycle (110) comprising a bottoming compressor section (water collector 124, which pumps fluid to HRSG 104 – see ¶ [0040], ll. 1-2) and a bottoming turbine section (steam turbines 112, 114, and 116),
wherein the intercooling heat exchanger (50) is in thermal communication with a flow of the working fluid (water from 124, which becomes steam 126) flowing from the bottoming compressor section (124) to the bottoming turbine section (112, 114, and 116).
Therefore, once Freund’s intercooling heat exchanger 50 is incorporated into Staubach between stages in the compressor section 910 and 912, Freund’s intercooling heat exchanger 50 will be in thermal communication with Freund’s second heat exchanger 932.
Regarding claim 11, Staubach, in view of Freund and Pang as discussed so far, teaches the invention as claimed and as discussed above for claim 10, except for the intercooling heat exchanger is upstream of the second heat exchanger in the bottoming cycle.
Freund further teaches (Fig. 2) the intercooling heat exchanger (50) is upstream (to the left) of the second heat exchanger (104) in the bottoming cycle (110).
Regarding claim 12, Staubach teaches (Fig. 9) a gas turbine engine assembly (as shown in Fig. 9) comprising:
a top cycle (900) comprising a compressor (910 and 912), a combustor (914) and a turbine (916 and 918) having an associated shaft (horizontal line through 916 and 918), wherein a mix of air (from 912) and a cryogenic fuel (from 942 – see also col. 16, ll. 41-43: “the auxiliary cooling source 942 is a cold fuel tank (e.g., a cryogenic fuel tank)”) is ignited in the combustor (914) to generate an exhaust gas flow that is expanded through the turbine (916 and 918) to drive the associated shaft and subsequently exhausted through an exhaust nozzle (920);
a bottoming cycle (902) comprising a bottoming compressor (930), a bottoming turbine (924), and a bottoming working fluid (supercritical CO2 – see col. 17, ll. 16-17) circulated within a closed bottoming circuit (path of 924 → 926 → 954 → 930 → 926 → 932 → 924 is a closed loop);
a first input of thermal energy (from the higher temperature of air after it is pressurized) from a core flow between stages of the compressor (910 and 912) – (note that thermal energy from 910 is inputted into 912);
a second heat exchanger (932) configured for communicating additional thermal energy from the exhaust gas flow (from 918) into the bottoming working fluid (from 926) of the bottoming cycle (902);
a cryogenic fuel system (940) comprising a cryogenic fuel storage tank (942 – col. 16, ll. 41-43), and a fuel flow path for routing the cryogenic fuel (path of 942 → 954 → 956 → 960 → 914) to the combustor (914) of the top cycle (900); and
a fuel/working fluid heat exchanger (954) providing thermal communication between a flow of the cryogenic fuel (from 942) within the fuel flow path and the working fluid (from 926) to cool the working fluid in the bottoming cycle (902).
However, Staubach does not teach an intercooling heat exchanger.
It is noted that Staubach’s second heat exchanger 932 would transfer a greater amount of thermal energy into the working fluid than an intercooling heat exchanger would transfer into the working fluid because Staubach’s second heat exchanger 932 is located in the exhaust gas flow path, where the temperature is much higher than the temperature of the core flow between stages in Staubach’s compressor section 910 and 912.
Freund teaches (Fig. 2) a similar system (100) comprising a core engine (10) and a bottoming cycle (110) where a bottoming working fluid (water/steam) is circulated;
an intercooling heat exchanger (50) where a first input of thermal energy from a core flow between stages of a compressor (14 and 16) is communicated into the bottoming working fluid (water from 124);
a second heat exchanger (104) downstream (to the right) from the intercooling heat exchanger (50) configured for communicating additional thermal energy from the exhaust gas flow (from 20) into the bottoming working fluid (from 124 and 126) fluid of the bottoming cycle (110) after the thermal energy from the core flow between stages of the compressor stages (14 and 16) is input into the bottoming working fluid (water from 124), wherein the second heat exchanger (104) is configured to input a greater amount of thermal energy into the bottoming working fluid than the intercooling heat exchanger (50) is configured to communicate into the bottoming working fluid – (intended use, note that intercooling heat exchanger 50 heats water from 124 to produce feedwater 126, which is then fed into an evaporator or a superheater in second heat exchanger 104 – see ¶ [0041], ll. 8-12. In order to evaporate or superheat feedwater 126, the temperature of the exhaust gas must be higher than the temperature of feedwater 126. Therefore, second heat exchanger 104 transfers heat at a higher temperature than intercooling heat exchanger 50. Since water from 124 also goes into second heat exchanger 104, second heat exchanger 104 will input a greater amount of thermal energy to the water from 124 than intercooling heat exchanger 50 will input to the water from 124).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach by including an intercooling heat exchanger where the first input of thermal energy from the core flow between the stages of the compressor is communicated into the bottoming working fluid, in order to facilitate reducing the energy expended by the high-pressure compressor to compress the air to the desired operating pressures, thereby allowing a designer to increase the pressure ratio of the gas turbine engine which results in an increase in energy extracted from the gas turbine engine and a high net operating efficiency of the gas turbine engine, as taught by Freund (¶ [0031], ll. 14-23), therefore providing:
the second heat exchanger (Staubach, 932) downstream from the intercooling heat exchanger (Freund, 50 – located at Staubach’s compressor 910 and 912) configured for communicating the additional thermal energy from the exhaust gas flow into the bottoming working fluid of the bottoming cycle after the thermal energy from the core flow between stages of the compressor (Staubach, 910 and 912) is input into the bottoming working fluid, wherein the second heat exchanger (932) is configured to input a greater amount of thermal energy into the bottoming working fluid than the intercooling heat exchanger (50) is configured to communicate into the bottoming working fluid – (intended use and as discussed above in Freund).
However, Staubach, in view of Freund, does not teach an exhaust gas heat exchange downstream of the second heat exchanger where the flow of cryogenic fuel is placed in thermal communication with the exhaust gas flow after cooling the flow of working fluid exhausted from the bottoming turbine section before injection into the combustor.
It is noted that Staubach teaches a supplemental heat exchanger (960) downstream of the second heat exchanger (954) and before the combustor (914), wherein the supplemental heat exchanger (960) “can be arranged to provide additional cooling for fluids of the engine or aircraft” (col. 16, ll. 62-64).
Pang teaches (Fig. 1) a similar system comprising:
a core engine (104) comprising a combustor (105) where a fuel (“Fuel” above 112) is mixed with compressed air (“Air” below 103) and ignited to generate an exhaust gas flow (154);
a bottoming cycle (106) where a working fluid (steam/water) is circulated;
a second heat exchanger (138) configured to communicate additional input of thermal energy from the exhaust gas flow (154) generated by the core engine (104) into the flow of working fluid; and further teaches:
an exhaust gas heat exchange (comprising 114, 156, 158, and 160, which form a closed cycle) downstream of the second heat exchanger (138) where the flow of fuel is placed in thermal communication with the exhaust gas flow (154) – (160 is in direct thermal communication with the exhaust gas flow) before injection into the combustor (105).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach, in view of Freund, by including an exhaust gas heat exchange (in place of Staubach’s supplemental heat exchanger 960) downstream of the second heat exchanger where the flow of cryogenic fuel is placed in thermal communication with the exhaust gas flow before injection into the combustor, in order to further raise the temperature of the flow of cryogenic fuel to a level that is higher than the temperature of the cryogenic fuel flow at an outlet of the fuel/working fluid heat exchanger, thereby effectuating a rapid heating of the cryogenic fuel flow during a startup sequence of the gas turbine engine, as taught by Pang (¶ [0030], ll. 13-17 and ¶ [0031], ll. 1-3), therefore providing:
where the flow of cryogenic fuel (Staubach, from 942) is placed in thermal communication with the exhaust gas flow (Staubach, to the right of 918) after cooling the flow of working fluid exhausted from the bottoming turbine section (Staubauch, 924) before injection into the combustor (Staubach, 914).
Regarding claim 13, Staubach, in view of Freund and Pang, teaches the invention as claimed and as discussed above for claim 12, and Staubach further teaches (Fig. 9) the second heat exchanger (932) is disposed within the exhaust gas flow (to the right of 918) of the top cycle (900) to provide thermal communication of heat from the exhaust gas flow to the bottoming working fluid (from 926) of the bottoming cycle (902).
Regarding claim 14, Staubach, in view of Freund and Pang as discussed so far, teaches the invention as claimed and as discussed above for claim 12, and the combination further teaches (Staubach, Fig. 9) the compressor (910 and 912) of the top cycle (900) comprises at least two stages (910 is one stage, 912 is another stage) and the intercooling heat exchanger (Freund, 50 – located at Staubach’s compressor 910 and 912) is in thermal communication with the core flow between the at least two stages in the compressor (910 and 912) of the top cycle (900), wherein thermal energy from the core flow (compressed air from 910) is communicated into the bottoming working fluid.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Staubach (US 11,506,124 B2), in view of Freund (US 2012/0159923 A1) and Pang (US 2014/0165572 A1), and in further view of Sen (US 2019/0249599 A1).
Regarding claim 9, Staubach, in view of Freund and Pang, teaches the invention as claimed and as discussed above for claim 8, and Staubach further teaches (Fig. 9) a generator (934 – col. 16, ll. 26-27: “the power output 934 may be connected to a generator”) driven by the bottoming turbine section (924) for generating electric power, and a turbine section (916 and 918) of the core engine (900).
However, Staubach, in view of Freund and Pang, does not teach an electric motor selectively coupled to a shaft of the core engine, the electric motor receiving electric power from the generator for supplementing shaft power generated by the turbine section of the core engine.
It is noted that Staubach further teaches “the power output 934 may be connected to a generator (e.g., to generate electricity) or mechanically connected to a fan to drive rotation of the fan (e.g., mechanical work)” (col. 16, ll. 26-29).
Sen teaches (Fig. 3) a similar system comprising a core engine (16) and a bottoming cycle (100); and
an electric motor (132 – see ¶ [0075], ll. 11-12: “the electric machine 132 of the turbomachine 16 may be configured as an electric motor”) selectively coupled to a shaft (36) of the core engine (16), the electric motor (132) receiving electric power from a generator (130) for supplementing shaft power generated by a turbine section (30) of the core engine (16) – (¶ [0075], ll. 6-10: “when the electric machine 130 of the closed cycle heat engine 100 (configured as an electric generator) generates electrical power, the electric power may be provided to the electric machine 132 of the turbomachine 16 to add power to the turbomachine 16”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach, in view of Freund and Pang, by including an electric motor selectively coupled to a shaft of the core engine, the electric motor receiving electric power from the generator for supplementing shaft power generated by the turbine section of the core engine, in order to allow for heat from the core engine, such as waste heat from the core engine, to be extracted, converted to useful work by the bottoming cycle, which may increase an overall efficiency of the core engine by converting waste heat to useful work, as taught by Sen (¶ [0075], ll. 13-19).
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Staubach (US 11,506,124 B2), in view of Freund (US 2012/0159923 A1) and Pang (US 2014/0165572 A1), and in further view of Sen (US 2019/0249599 A1).
Regarding claim 20, Staubach, in view of Freund and Pang, teaches the invention as claimed and as discussed above for claim 12, and Staubach further teaches (Fig. 9) a generator (934 – col. 16, ll. 26-27: “the power output 934 may be connected to a generator”) driven by the bottoming turbine (924) for generating electric power, and a turbine (916 and 918) of the top cycle (900).
However, Staubach, in view of Freund, does not teach an electric motor selectively coupled to the associated shaft of the top cycle, the electric motor receiving electric power from the generator for supplementing shaft power generated by the turbine of the top cycle.
It is noted that Staubach further teaches “the power output 934 may be connected to a generator (e.g., to generate electricity) or mechanically connected to a fan to drive rotation of the fan (e.g., mechanical work)” (col. 16, ll. 26-29).
Sen teaches (Fig. 3) a similar system comprising a top cycle (16) and a bottoming cycle (100); and
an electric motor (132 – see ¶ [0075], ll. 11-12: “the electric machine 132 of the turbomachine 16 may be configured as an electric motor”) selectively coupled to an associated shaft (36) of the top cycle (16), the electric motor (132) receiving electric power from a generator (130) for supplementing shaft power generated by a turbine (30) of the top cycle (16) – (¶ [0075], ll. 6-10: “when the electric machine 130 of the closed cycle heat engine 100 (configured as an electric generator) generates electrical power, the electric power may be provided to the electric machine 132 of the turbomachine 16 to add power to the turbomachine 16”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to modify Staubach, in view of Freund, by including an electric motor selectively coupled to the associated shaft of the top cycle, the electric motor receiving electric power from the generator for supplementing shaft power generated by the turbine of the top cycle, in order to allow for heat from the core engine, such as waste heat from the core engine, to be extracted, converted to useful work by the bottoming cycle, which may increase an overall efficiency of the core engine by converting waste heat to useful work, as taught by Sen (¶ [0075], ll. 13-19).
Response to Arguments
Applicant’s arguments regarding the new limitations in claims 1 and 12 have been considered but are moot in view of the new ground(s) of rejection, necessitated by Applicant's amendments. To the extent possible, Applicant's arguments have been addressed in the body of the rejections at the appropriate locations.
Applicant’s arguments against the Pang prior art have been fully considered but are not persuasive.
Regarding Applicant’s argument that “none of the elements 114, 156, 158 and 160 exposes fuel to an exhaust gas flow. Instead, a working fluid flow is used to heat the fuel flow. The exhaust gas flow heats a working fluid within an energy storage charge heat exchanger 160 (See at least paragraph 11 of Pang)”, it is evident from Pang’s Fig. 1 that the exhaust gas 154 goes through HRSG 116 to heat every element within HRSG 116. The remnants of the exhaust gas can be seen on the right-hand side of HRSG 116, which shows “Stack”. While Pang states that a working fluid within the HRSG is used to transfer energy to the thermal storage medium, the working fluid within the HRSG gets all of its thermal energy from exhaust gas 154. As evidenced by ¶ [0033], “thermal storage unit 110 can be in an off-mode where all of the exhaust energy from the gas turbine is applied to heat working fluid (e.g., water/steam) sent from HRSG 116 to steam turbine engine 118 for expansion work”. This shows that when thermal storage unit 110 is in an on-mode, some of the thermal energy from the exhaust gas flow is transferred to the thermal storage medium.
Alternatively, the loop that provides thermal energy to heat exchanger 114 may be reinterpreted as 114 → 156 → 116 → 158 → 114. In this case, the exhaust gas 154 directly heats HSRG 116, which then passes off thermal energy to element 158. This is no different from saying that the exhaust gas 154 directly heats an element (in this case, 160) within HSRG 116, which then passes off thermal energy to element 158.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to HENRY NG whose telephone number is (571)272-2318. The examiner can normally be reached M-F 9:30 AM - 6:30 PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Devon Kramer can be reached at 571-272-7118. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/HENRY NG/Examiner, Art Unit 3741 /DEVON C KRAMER/Supervisory Patent Examiner, Art Unit 3741