DETAILED ACTION
This is a non-final rejection in response to RCE filed 12/23/25. Claims 1-17 are currently pending.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-17 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Rejections - 35 USC § 102
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) 1-3, 5, 7-9, 13, and 17 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Deng (US 20210254547).
Regarding independent claim 1, Deng teaches a combined cycle power plant (CCPP) comprising: a gas turbine 12 having a compressor section 50, a combustion section 52, and a turbine section 54; a heat recovery steam generator (HRSG) 14 that receives a flow of exhaust gas from the turbine section wherein the HRSG includes water/steam conveying components (this is inherent for all HRSG, as there must be pipes and other ways of moving the water and steam); a fuel heating system 72 comprising a fuel supply line and a high temperature heat exchanger 86, the fuel supply line fluidly coupled to the combustion section, the high temperature heat exchanger disposed in thermal communication on the fuel supply line; and a thermal fluid system 70 thermally coupling the HRSG to the high temperature heat exchanger wherein the high temperature heat exchanger is fluidly isolated from all of the water/steam conveying components of the HRSG, and wherein the thermal fluid system is at least partially disposed in the HRSG [0026-0029].
Regarding dependent claim 2, Deng teaches wherein the thermal fluid system comprises a dedicated loop extending at least partially through the HRSG and having a dedicated heat exchanger disposed within the HRSG [0027].
Regarding dependent claim 3, Deng teaches wherein the dedicated loop circulates a non-water thermal fluid [0028].
Regarding dependent claim 5, Deng teaches wherein the dedicated loop further comprises a recirculation pump 74 disposed outside of the HRSG.
Regarding dependent claim 7, Deng teaches wherein the dedicated heat exchanger 82 of the dedicated loop extends within the HRSG from an outlet of the HRSG to upstream of the first high pressure economizer with respect to the flow of exhaust gas through the HRSG [0027[.
Regarding dependent claim 8, Deng teaches wherein the thermal fluid system comprises an exhaust extraction system including an exhaust extraction duct extending from an inlet within the HRSG to the high temperature heat exchanger (TCA cooler 32 and ECA cooler 34,36 receive compressed air from compressor 50) [0023,0026].
Regarding dependent claim 9, Deng teaches wherein the HRSG further comprises, in a serial flow order from upstream to downstream with respect to the flow of exhaust gas through the HRSG, a first high pressure economizer, an intermediate pressure economizer, a second high pressure economizer, and a low pressure economizer; and wherein the inlet is disposed upstream of first high pressure economizer with respect to the flow of exhaust gas through the HRSG [0027].
Regarding independent claim 13, Deng teaches a combined cycle power plant (CCPP) comprising: a gas turbine 12 having a compressor section 50, a combustion section 52, and a turbine section 54; a heat recovery steam generator 14 (HRSG) that receives a flow of exhaust gas from the turbine section, wherein the HRSG comprises, in a serial flow order from upstream to downstream with respect to the flow of exhaust gas through the HRSG, a first high pressure economizer, an intermediate pressure economizer, a second high pressure economizer, and a low pressure economizer; a fuel heating system 72 comprising a fuel supply line and a high temperature heat exchanger 86,88, the fuel supply line fluidly coupled to the combustion section, the high temperature heat exchanger disposed in thermal communication on the fuel supply line; and a thermal fluid system 70 thermally coupling the HRSG to the high temperature heat exchanger, wherein the thermal fluid system comprises a dedicated loop extending at least partially through the HRSG and having a dedicated heat exchanger disposed within the HRSG, wherein the dedicated heat exchanger of the dedicated loop extends within the HRSG from an outlet of the HRSG to upstream of the first high pressure economizer with respect to the flow of exhaust gas through the HRSG [0027].
Regarding dependent claim 17, Deng teaches wherein the thermal fluid system circulates a non-water thermal fluid [0028-0029].
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.
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Deng in view of Druvo et al. (RU 2595192).
Regarding dependent claim 4, Deng teaches the invention as claimed and discussed above. Deng teaches a CCPP with a dedicated loop but is silent to further comprises an expansion tank disposed outside of the HRSG.
Druvo teaches it was known to further comprise an expansion tank 42 disposed outside of the HRSG9.
It is noted that the use of a known prior art structure (in this case the use of an expansion tank taught by Druvo), to obtain predictable results (in this maintaining stable pressure in the loop, and preventing over-pressurization of the heat exchanger) was an obvious extension of prior art teachings, KSR; MPEP 2141 III A.
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Deng in view of Uechi et al. (US 2020/0284169).
Regarding dependent claim 6, Deng teaches the invention as claimed and discussed above. Deng teaches wherein the HRSG further comprises, in a serial flow order from upstream to downstream with respect to the flow of exhaust gas through the HRSG, a first high pressure economizer 48, an intermediate pressure economizer 46, and a low pressure economizer 44.
Deng is silent to a second high pressure economizer.
Uechi teaches it was known to have a second high pressure economizer 25i [0054].
It is noted that the use of a known prior art structure (in this case the use of a second high pressure economizer taught by Uechi), to obtain predictable results (in this case improved heat transfer efficiency and more refined control of feedwater) was an obvious extension of prior art teachings, KSR; MPEP 2141 III A.
Claim(s) 10-11, and 14-15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Deng in view of Briesch et al. (US 5845481).
Regarding dependent claim 10 and independent claim 14, Deng teaches the invention as claimed and discussed above. Deng is silent to wherein the exhaust extraction system includes an exhaust return duct extending from the high temperature heat exchanger to an outlet within the HRSG.
Briesch teaches it was known to have return pipelines to the steam condenser and economizers (col. 3, l. 60- col. 4, l. 15)
It would have been obvious to one of ordinary skill in the art at the time of filing to modify Deng such that an exhaust return duct as taught by Briesch, such that it extends from a heat exchanger to an outlet within the HRSG.
It is noted that the use of a known technique (in this case the use exhaust extracted to heat fuel as taught by Briesch), to improve a similar device (in this case the use the exhaust extraction to heat the fuel) was an obvious extension of prior art teachings, KSR, MPEP 2141 III C.
Regarding dependent claim 11 and 15, Deng in view of Briesch teaches the invention as claimed and discussed above. Briesch further teaches wherein the outlet 82 is disposed downstream of the low pressure economizer (LTE of Deng) with respect to the flow of exhaust gas through the HRSG (see fig. 4).
Claim(s) 12 and 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Deng in view of Briesch and further in view of Ranasinghe et al. (US 2010/0126181).
Regarding dependent claim 12 and 16, Deng in view of Briesch teaches the invention as claimed and discussed above. Deng in view of Briesch is silent to further teaches wherein the exhaust extraction system includes a fan disposed along the exhaust return duct between the high temperature heat exchanger and the outlet.
Ranasinghe teaches wherein the exhaust extraction system includes a fan 170 disposed along the exhaust return duct between the high temperature heat exchanger and the outlet [0030,0049].
It would have been obvious to one of ordinary skill in the art at the time of filing to modify Deng in view of Briesch with the fan of Ranasinghe in the exhaust return duct, as Ranasinghe teaches increased efficiency [0049].
Conclusion
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/CRAIG KIM/
Primary Examiner
Art Unit 3741