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 .
Claims 1, 6-13, 15-23 are currently being examined.
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:
Determining the scope and contents of the prior art.
Ascertaining the differences between the prior art and the claims at issue.
Resolving the level of ordinary skill in the pertinent art.
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) 1, 6, 8-9, 11, 13, 15 and 23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Seki et al. 20220045573 in view of Barnett et al. 20140077507, Laurello et al. 20140311157, and Coffinberry 5305616.
Regarding independent claim 1, Seki discloses an assembly for an aircraft propulsion system (Fig. 1 para. 0026):
a compressor section (31,32 Fig. 1) comprising a low pressure compressor section (31 Fig. 1) and a high pressure compressor section (32 Fig. 1);
a combustor section (33 Fig. 1);
a turbine section (34,35 Fig. 1);
a core flowpath (core flowpath 30 Fig. 1 para. 0031) extending through the compressor section, the combustor section and the turbine section from an inlet (inlet of 31 in Fig. 1) into the core flowpath to an exhaust (39 Fig. 1) from the core flowpath;
a tail cone structure (44 Fig. 1) arranged at the exhaust from the core flowpath, the tail cone structure forming an inner peripheral boundary of the exhaust from the core flowpath (per para. 0030 at least a part of the tail cone 44 defines a boundary of the exhaust 39 from the core flowpath which is an inner peripheral boundary as shown in Fig. 1); and
a ventilation system configured to bleed compressed air from the core flowpath along the compressor section to provide ventilation air (as described in para. 0044, core
air duct 63 in Fig. 1 is connected to an air bleed port provided at a portion of the casings of the compressors 31,32 and core air is extracted via the air bleed port), and the ventilation system including a ventilation air circuit (ventilation air circuit from compressor section 31, 32 to 45 via 63V to 60 to 61 in Fig. 1) and the ventilation system configured to direct the ventilation air into an internal volume (volume within heat shield 45 in Fig. 1; bleed air is directed via valve 63V shown in Figs. 1 and 2 into junction box 60 and then into cooling air ducts 61 which extend to 45) in the tail cone structure (45 is within 44 in Fig. 1; ventilation air sent to the tail cone is for cooling generator G disposed in the tail cone as shown in Fig. 1);
the ventilation air circuit fluidly coupled between a ventilation circuit bleed port (per para. 0044: “core air duct 63 is connected to an air bleed port (not illustrated) provided at a portion of the casings of the compressors (the low pressure compressor 31 and the high pressure compressor 32)”; see annotated Fig. 1) and the internal volume (volume within 45 in Fig. 1), and the ventilation circuit bleed port configured to bleed the compressed air from the core flowpath along the high pressure compressor section to provide the ventilation air within the ventilation air circuit (per para. 0044 core air from the high pressure compressor, i.e., ventilation air, is extracted via the air bleed port, i.e., ventilation circuit bleed port, and the compressed air is supplied to cooling air ducts 61 via junction box 60).
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Seki is silent regarding the ventilation system including an air-to-air heat exchanger and a cooling air circuit, the ventilation system configured to direct the ventilation air through the air-to-air heat exchanger; the ventilation air circuit extending through the air-to-air heat exchanger; the cooling air circuit extending through the air-to- air heat exchanger and fluidly coupled to a cooling circuit bleed port, the cooling circuit bleed port configured to bleed additional compressed air from the core flowpath along the high pressure compressor section to provide the cooling air within the cooling air
circuit, the cooling circuit bleed port disposed upstream of the ventilation circuit bleed port along the core flowpath, the cooling air circuit extending between the cooling circuit bleed port and a cooling circuit outlet, the cooling circuit outlet fluidly coupled with a bypass flowpath, and the cooling air circuit fluidly independent of the ventilation air circuit; and the air-to-air heat exchanger configured to transfer heat energy from the ventilation air into cooling air; wherein the cooling circuit bleed port is separated from the ventilation circuit bleed port along the core flowpath by five or more stages of the high pressure compressor section.
Barnett ‘507 teaches a gas turbine engine (10 Fig. 1) with a generator (30 Fig. 1 para. 0013) in a tail cone (per para. 0013 generator 30 may be in an exhaust cone, i.e., tail cone, which is shown in Fig. 1). Barnett teaches ventilation air from compressor 14 of the gas turbine engine may be used to cool generator 30 and the ventilation air may be directed through a heat exchanger 32 to cool the ventilation air going to the generator (Fig. 2; para. 0017).
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 Seki to have the ventilation system include a heat exchanger, the ventilation system configured to direct the ventilation air through the heat exchanger; the ventilation circuit extending through the heat exchanger as taught by Barnett ‘507 to cool the ventilation air going to the tail cone to cool the generator.
Seki in view of Barnett ‘507 is silent regarding the heat exchanger is an air-to-air heat exchanger and the ventilation system includes a cooling air circuit, the cooling air circuit extending through the air-to-air heat exchanger and fluidly coupled to a cooling
circuit bleed port, the cooling circuit bleed port configured to bleed additional compressed air from the core flowpath along the high pressure compressor section to provide the cooling air within the cooling air circuit, the cooling circuit bleed port disposed upstream of the ventilation circuit bleed port along the core flowpath, the cooling air circuit extending between the cooling circuit bleed port and a cooling circuit outlet, the cooling circuit outlet fluidly coupled with a bypass flowpath, and the cooling air circuit fluidly independent of the ventilation air circuit; and the air-to-air heat exchanger configured to transfer heat energy from the ventilation air into cooling air; wherein the cooling circuit bleed port is separated from the ventilation circuit bleed port along the core flowpath by five or more stages of the high pressure compressor section.
Laurello teaches a gas turbine engine with a cooling air circuit delivering cooling air from a compressor to a hot section of the gas turbine engine (Fig. 1). Laurello teaches:
a ventilation system (Fig. 1 and 2A-2C) configured to direct ventilation air through an air-to-air heat exchanger (82 Fig. 2C); a ventilation air circuit extending through the air-to-air heat exchanger (in Figs. 2A-2C ventilation air circuit from ventilation air source at 48 in compressor section 12 extending via piping 50 through 82 to 34B of turbine section 18); and
a cooling air circuit extending through the air-to-air heat exchanger (in Figs. 2A- 2C cooling air circuit from cooling air source at 42 in compressor section extending via piping 44 through 82 to 34D of turbine section 18) and fluidly coupled to a cooling circuit bleed port (42 Fig 2B), the cooling circuit bleed port configured to bleed additional compressed air from a core flowpath (flowpath CA in Fig. 1, 2A-2B) along a compressor
section (12 Fig. 1) to provide the cooling air within the cooling air circuit, and the cooling circuit bleed port disposed upstream of the ventilation circuit bleed port along the core flowpath (42 is upstream of 48 in Fig. 2B);
the air-to-air heat exchanger configured to transfer heat energy from ventilation air into cooling air (heat from ventilation air VA2 is transferred to cooling air VA1 within 82 per para. 0021);
wherein the cooling circuit bleed port is separated from the ventilation circuit bleed port along the core flowpath by five or more stages of the high pressure compressor section (42 is at fifth stage and 48 is at eleventh stage per para. 0021 such that 42 and 48 are separated by six stages which is within the claimed five or more stages).
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 Seki in view of Barnett ‘507 to have the heat exchanger be an air-to-air heat exchanger and the ventilation system includes a cooling air circuit, the cooling air circuit extending through the air-to-air heat exchanger and fluidly coupled to a cooling circuit bleed port, the cooling circuit bleed port configured to bleed additional compressed air from the core flowpath along the high pressure compressor section to provide the cooling air within the cooling air circuit, the cooling circuit bleed port disposed upstream of the ventilation circuit bleed port along the core flowpath; and the air-to-air heat exchanger configured to transfer heat energy from the ventilation air into cooling air; wherein the cooling circuit bleed port is separated from the ventilation circuit bleed port along the core flowpath by five or more stages of the high pressure compressor section as taught by Laurello to cool the higher
temperature ventilation air from the compressor with the lower temperature cooling air taken further upstream from the compressor to control temperature of the ventilation air and temperature of the cooling air relative to each other and relative to predetermined temperature constraints for the respective components being cooled by each air flow (Laurello para. 0023) and each upstream stage of the compressor section is of a lower temperature than subsequent downstream stages, such that the higher the number of stages between the cooling circuit bleed port and the ventilation bleed port, the higher the temperature differential between the two bleed ports may be obtained, and in the invention of Seki in view of Barnett ‘507 and Laurello with the ventilation air being directed to the tail cone to cool a generator and the cooling air being directed to the turbine to cool a turbine component, the cooling air circuit is fluidly independent of the ventilation air circuit as claimed.
Seki in view of Barnett ‘507 and Laurello are silent regarding the cooling air circuit extending between the cooling circuit bleed port and a cooling circuit outlet, the cooling circuit outlet fluidly coupled with a bypass flowpath.
Coffinberry teaches a gas turbine engine (10 Fig. 1) with a cooling system 110 with an air-to-air heat exchanger 130 in Fig. 2 which has an inlet 144 and an outlet 146 for a first airflow, i.e., a cooling air circuit, providing cooling to heat exchanger 130 and has an inlet 148 and an outlet 150 for a second airflow receiving cooling from heat exchanger 130, where the first airflow is lower in temperature and pressure than the second airflow and the first airflow is preferably discharged into the fan bypass duct 38 with an aft component of velocity (col 3 lines 62-68 to col 4 lines 1-13), i.e., cooling circuit outlet 146 is fluidly coupled with a bypass flowpath.
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 Seki in view of Barnett ‘507 and Laurello to have the cooling air circuit extending between the cooling circuit bleed port and a cooling circuit outlet, the cooling circuit outlet fluidly coupled with a bypass flowpath as taught by Coffinberry for thrust recovery by adding the cooling air to the bypass airflow from the fan which provides most of the engine thrust for the aircraft (col 1 lines 41-43).
Regarding claim 6, Seki in view of Barnett ‘507, Laurello, and Coffinberry teaches all that is claimed above but Seki is silent wherein the ventilation system further includes
an air-to-fuel heat exchanger; and
a fuel circuit extending from a fuel source through the air-to-fuel heat exchanger
to a component of the aircraft propulsion system;
the ventilation air circuit further extending through the air-to-fuel heat exchanger downstream of the air-to-air heat exchanger; and
the air-to-fuel heat exchanger configured to transfer additional heat energy from the ventilation air into fuel flowing within the fuel circuit.
Laurello further teaches
an air-to-fuel heat exchanger (84 Figs. 1 and 2C; para. 0022 describes secondary cooler 84 may use fuel as a coolant to cool ventilation air VA2 such that 84 is an air-to-fuel heat exchanger); and
a fuel circuit extending through the air-to-fuel heat exchanger (in order for fuel to be a coolant in 84, a fuel circuit extending through 84 is necessary) to a combustor ([0022] describes fuel used as a coolant in air-to-fuel heat exchanger 84 is to be supplied to combustor 16, such that the fuel circuit extends through 84 to combustor 16 so that compressed air is mixed with the fuel and ignited to produce high temperature combustion gases per [0013]);
the ventilation air circuit further extending through the air-to-fuel heat exchanger
downstream of the air-to-air heat exchanger (in Figs. 1 and 2A-2C, piping 50 carrying
ventilation air VA2 extends through 82 and then through 84, such that 84 is downstream of 82); and
the air-to-fuel heat exchanger configured to transfer additional heat energy from the ventilation air into fuel flowing within the fuel circuit (per para. 0022, secondary cooler 84 provides additional cooling to ventilation air VA2 and secondary cooler 84
may be required to cool the ventilation air VA2 to a desired temperature if the cooling air VA1 in heat exchanger 82 does not have the capacity to cool the ventilation air VA2 all the way down to the desired temperature without the cooling air VA1 being heated above a preferred temperature, such that 84 is configured to transfer additional heat energy from VA2 into fuel flowing within the fuel circuit).
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 Seki in view of Barnett ‘507, Laurello, and Coffinberry wherein the ventilation system further includes an air-to-fuel heat exchanger; and a fuel circuit extending through the air-to-fuel heat exchanger to a component of the aircraft propulsion system which is the combustor; the ventilation air circuit further extending through the air-to-fuel heat exchanger and the air-to-air heat exchanger; and the air-to-fuel heat exchanger configured to transfer additional heat energy from the ventilation air into fuel flowing within the fuel circuit as taught by Laurello to provide additional cooling to the ventilation air with the fuel to cool the ventilation air to a desired temperature if the cooling air from the air-to-air heat exchanger does not have the capacity to cool the ventilation air all the way down to the desired temperature without the cooling air being heated above a preferred temperature, and to supply the fuel to the combustor to mix with compressed air and be ignited to produce high temperature combustion gases.
Coffinberry further teaches a fuel source which is a fuel tank from which fuel may flow to a heat exchanger and to a combustor (col 6 lines 54-62).
"The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results. . . . [W]hen a patent 'simply arranges old elements with each performing the same function it had been known to perform' and yields no more than one would expect from such an arrangement, the combination is obvious." KSR at 1395-66 (citing Sakraida v. AG Pro, Inc., 425 U.S. 273, 282 (1976)).
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 Seki in view of Barnett ‘507, Laurello, and Coffinberry to include a fuel source as further taught by Coffinberry as combining prior art elements according to known methods to yield predictable results, in this case having a fuel source which is a fuel tank to provide fuel to the fuel circuit.
Regarding claim 8, Seki in view of Barnett ‘507, Laurello, and Coffinberry teaches all that is claimed above and Seki discloses the ventilation air circuit fluidly coupled between the ventilation circuit bleed port (per para. 0044: “core air duct 63 is connected to an air bleed port (not illustrated) provided at a portion of the casings of the compressors (the low pressure compressor 31 and the high pressure compressor 32)”) and the internal volume (volume within 45 in Fig. 1), the ventilation circuit bleed port configured to bleed the compressed air from the core flowpath along the compressor section to provide the ventilation air within the ventilation air circuit (per para. 0044 core air from the compressor, i.e., ventilation air, is extracted via the air bleed port, i.e., ventilation circuit bleed port, and the compressed air is supplied to cooling air ducts 61 via junction box 60), but Seki is silent regarding the ventilation system further includes
an air-to-working fluid heat exchanger;
the ventilation air circuit extending through the air-to-working fluid heat exchanger; and
a working fluid circuit extending from a working fluid source, through the air-to-
working fluid heat exchanger to a component of the aircraft propulsion system;
the air-to-working fluid heat exchanger configured to transfer heat energy from the ventilation air into a working fluid flowing within the working fluid circuit.
Laurello further teaches
an air-to-working fluid heat exchanger (84 Figs. 1 and 2C; para. 0022 describes secondary cooler 84 may use fuel as a coolant to cool ventilation air VA2, where fuel is a working fluid, such that 84 is an air-to-working fluid heat exchanger);
the ventilation air circuit extending through the air-to-working fluid heat exchanger (in Figs. 1 and 2A-2C, piping 50 carrying ventilation air VA2 extends through 82 and then through 84); and
a working fluid circuit extending through the air-to-working fluid heat exchanger (in order for fuel to be a coolant in 84, a fuel circuit extending through 84 is necessary) to a combustor ([0022] describes fuel used as a coolant in air-to-working fluid heat exchanger 84 is to be supplied to combustor 16, such that the fuel circuit extends through 84 to combustor 16 so that compressed air is mixed with the fuel and ignited to produce high temperature combustion gases per [0013]);
the air-to-working fluid heat exchanger configured to transfer heat energy from the ventilation air into a working fluid flowing within the working fluid circuit (per para. 0022, secondary cooler 84 provides additional cooling to ventilation air VA2 and secondary cooler 84 may be required to cool the ventilation air VA2 to a desired temperature if the cooling air VA1 in heat exchanger 82 does not have the capacity to cool the ventilation air VA2 all the way down to the desired temperature without the cooling air VA1 being heated above a preferred temperature, such that 84 is configured to transfer additional heat energy from VA2 into fuel flowing within the fuel circuit).
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 Seki in view of Barnett ‘507, Laurello, and Coffinberry wherein the ventilation system further includes an air-to-working fluid heat exchanger; the ventilation air circuit extending through the air-to-working fluid heat exchanger; and a working fluid circuit extending through the air-to-working fluid heat exchanger to a component of the aircraft propulsion system which is the combustor; the air-to-working fluid heat exchanger configured to transfer heat energy from the ventilation air into a working fluid which is fuel flowing within the working fluid circuit as taught by Laurello to provide additional cooling to the ventilation air to cool the ventilation air to a desired temperature if the cooling air from the air-to-air heat exchanger does not have the capacity to cool the ventilation air all the way down to the desired temperature without the cooling air being heated above a preferred temperature, and to supply fuel as the working fluid to the combustor to mix with compressed air and be ignited to produce high temperature combustion gases.
Coffinberry further teaches a working fluid source which is a fuel tank from which fuel may flow to a heat exchanger and to a combustor (col 6 lines 54-62).
"The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results. . . . [W]hen a patent 'simply arranges old elements with each performing the same function it had been known to perform' and yields no more than one would expect from such an arrangement, the combination is obvious." KSR at 1395-66 (citing Sakraida v. AG Pro, Inc., 425 U.S. 273, 282 (1976)).
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 Seki in view of Barnett ‘507, Laurello, and Coffinberry to include a working fluid source as further taught by Coffinberry as combining prior art elements according to known methods to yield predictable results, in this case having a working fluid source which is a fuel tank to provide fuel to the working fluid circuit.
Regarding claim 9, the invention of Seki in view of Barnett ‘507, Laurello, and Coffinberry teaches the working fluid source comprises a fuel source configured to direct fuel into the working fluid circuit, wherein the working fluid comprises fuel (as discussed above in claim 8, Laurello teaches a fuel circuit is the working fluid circuit and Coffinberry teaches a working fluid source which is a fuel tank for providing fuel as a coolant in a working fluid circuit and the fuel to be combusted in the combustor).
Regarding claim 11, Seki in view of Barnett ‘507, Laurello, and Coffinberry teaches all that is claimed above and Seki further discloses an electronic device (generator G in Fig. 1 para. 0036) located within the internal volume (G is within 45 in Fig. 1);
the ventilation system configured to cool the electronic device with the ventilation air (per para. 0044 bleed air is supplied to cooling air ducts 61 to keep generator G and electric power cables 51 at or below an acceptable upper temperature limit when valve 63V is open).
Regarding claim 13, Seki in view of Barnett ‘507, Laurello, and Coffinberry teaches all that is claimed above and Seki further discloses wherein the electric device is configurable as an electric generator (per para. 0036 generator G is formed to cause a three-phase AC to be generated, i.e., G is an electric generator).
Regarding claim 15, Seki in view of Barnett ‘507, Laurello, and Coffinberry teaches all that is claimed above and Seki further discloses a propulsor rotor (rotor 2R of the fan 2 in Fig. 1); and
an engine core (core engine 3 in Fig. 1 para. 0028) configured to drive rotation of the propulsor rotor (per para. 0028 exhaust flow from the combustor section 33 drives the turbine section 34,35 and rotor 35R drives 2R), the engine core including the
compressor section, the combustor section and the turbine section (3 includes 31,32, 33, 34 and 35 in Fig. 1).
Regarding claim 23, Seki in view of Barnett ‘507, Laurello, and Coffinberry teaches all that is claimed above and Seki further discloses the internal volume comprises a cavity located within the tail cone structure (as seen in Fig. 1, heat shield 45 forms a cavity defining the internal volume located within tail cone structure 44); and
the core flowpath is located radially outboard of the internal volume (as shown in Fig. 1, core flowpath 30 is located radially outboard of the internal volume within heat shield 45).
Claim(s) 7-8 and 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Seki et al. 20220045573 in view of Barnett et al. 20140077507, Laurello et al. 20140311157 and Coffinberry 5305616 as applied to claim 1 above and further in view of Niergarth et al. 20190218971.
Regarding claim 7, Seki in view of Barnett ‘507, Laurello, and Coffinberry teaches all that is claimed above but Seki is silent wherein the ventilation system further includes
an air-to-oil heat exchanger; and
an oil circuit extending from an oil source through the air-to-oil heat exchanger to
a component of the aircraft propulsion system;
the ventilation air circuit further extending through the air-to-oil heat exchanger downstream of the air-to-air heat exchanger; and
the air-to-oil heat exchanger configured to transfer additional heat energy from the ventilation air into oil flowing within the oil circuit.
Niergarth teaches a gas turbine engine (10 Fig. 1) including a ventilation air circuit (105 Fig. 3) comprising a heat exchanger (100 Fig. 3) which may include one or more heat exchanger elements (200 Fig. 3 para. 0050) in serial flow arrangement with one another relative to a flow of compressed air (99 Fig. 3 which is compressed air from compressor section 21 of Fig. 1, i.e., ventilation air) to a hot section (33 Fig. 3 which comprises the combustion section 26, the turbine or expansion section 31, and the jet
exhaust nozzle section 37 per para. 0030). The hot section is analogous to the tail cone structure of Seki in that the tail cone structure is in a jet exhaust nozzle section.
Niergarth teaches a cooling air circuit (circuit from one of coolant supply systems 110 providing cooling air 109 to one of 200 with egressing cooling air 111 flowing from
one of 200 in Fig. 3; per para. 0056 one of coolant supply systems 110 may be one or more compressor bleeds which supply the cooling circuit with cooling air) and an air-to- air heat exchanger (one of 200 in Fig. 3).
Niergarth also teaches an air-to-oil heat exchanger (another one of 200 Fig. 3 different than the air-to-air heat exchanger 200; per para. 0056 another one of the systems 110 supplying another one of coolant 109 may be a lubricant system, i.e., an oil system, such that another one of 200 is an air-to-oil heat exchanger); and
an oil circuit (a circuit of lubricant 109, i.e., oil, extends from another one of 110 and
through another one of 200 in Fig. 3) extending from an oil source (per [0056] coolant supply system 110 for supplying coolant, i.e., 110 is a coolant source, may be a lubricant system for supplying lubricant, i.e., an oil system for supplying oil which is an oil source) through the air-to-oil heat exchanger to a component of the aircraft propulsion system (per [0059] oil flows through another one of 200 to a bearing assembly of gas turbine engine 10, i.e., an aircraft propulsion system; per [0032] gte 10 provides propulsive thrust and [0075] describes operational flight phases such as cruise);
the ventilation air circuit further extending through the air-to-oil heat exchanger and the air-to-air heat exchanger (one of 200 and another one of 200 are shown in series along the ventilation air circuit 105 in Fig. 3 with the ventilation air circuit extending through each); and
the air-to-oil heat exchanger configured to transfer additional heat energy from the ventilation air into oil flowing within the oil circuit (per para. 0052 and with reference to Fig. 3, the flow of ventilation air 101(b) egressing a second of a serial arrangement of heat exchanger elements 200 generally defines an outlet temperature and outlet pressure within desired ranges and less than those of the portion of the flow of ventilation air 101(a), meaning a second heat exchanger 200, i.e., air-to-oil heat
exchanger, lowers the temperature of the ventilation air further by transferring additional heat energy from the ventilation air).
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 Seki in view of Barnett ‘507, Laurello, and Coffinberry wherein the ventilation system further includes an air-to-oil heat exchanger; and an oil circuit extending from an oil source through the air-to-oil heat exchanger to a component of the aircraft propulsion system; the ventilation air circuit further extending through the air-to-oil heat exchanger and the air-to-air heat exchanger; and the air-to-oil heat exchanger configured to transfer additional heat energy from the ventilation air into oil flowing within the oil circuit as taught by Niergarth to obtain a desired outlet temperature, outlet pressure, or both, of the ventilation air based at least on an operating condition of the aircraft propulsion system (Niergarth para. 0015), and to maintain a temperature of the bleed air coolant within an operating constraint relative to a desired outlet temperature and/or pressure of the flow of bleed air coolant egressed from the air-to-air heat exchanger, and to maintain or adjust a temperature/pressure of the oil coolant within an operating constraint relative to a desired outlet temperature and/or pressure of the flow of oil coolant egressed from the air-to-oil heat exchanger such as within a maximum oil temperature such as for a bearing assembly (Niergarth paras. 0017, 0059).
Although Seki in view of Barnett ‘507, Laurello, Coffinberry and Niergarth does not explicitly teach the ventilation air circuit further extending through the air-to-oil heat exchanger downstream of the air-to-air heat exchanger, it would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to choose from a finite number of options of positioning the air-to-oil heat exchanger in series with the air-to-air heat exchanger along the ventilation circuit to obtain both the desired temperature of the ventilation air and the desired temperature of each coolant, additional bleed air and oil, and arrive at the claimed invention. "When there is a design need or market pressure to solve a problem and there are a finite number of identified, predictable solutions, a person of ordinary skill has good reason to pursue the known options within his or her technical grasp. If this leads to the anticipated success, it is likely the product not of innovation but of ordinary skill and common sense." KSR at 1397.
Regarding claim 8, Seki in view of Barnett ‘507, Laurello, and Coffinberry teaches all that is claimed above and Seki discloses the ventilation air circuit (ventilation air circuit from compressor section 31, 32 to 45 via 63V to 60 to 61 in Fig. 1)
fluidly coupled between a ventilation circuit bleed port (per para. 0044: “core air duct 63 is connected to an air bleed port (not illustrated) provided at a portion of the casings of the compressors (the low pressure compressor 31 and the high pressure compressor 32”) and the internal volume (volume within 45 in Fig. 1), the ventilation
circuit bleed port configured to bleed the compressed air from the flowpath along the compressor section to provide the ventilation air within the ventilation air circuit (per para. 0044 core air from the compressor, i.e., ventilation air, is extracted via the air bleed port and the compressed air is supplied to cooling air ducts 61 via junction box 60), but Seki is silent regarding the ventilation system further includes
an air-to-working fluid heat exchanger;
the ventilation air circuit extending through the air-to-working fluid heat exchanger; and
a working fluid circuit extending from a working fluid source, through the air-to-
working fluid heat exchanger to a component of the aircraft propulsion system;
the air-to-working fluid heat exchanger configured to transfer heat energy from
the ventilation air into a working fluid flowing within the working fluid circuit.
Niergarth teaches a gas turbine engine (10 Fig. 1) including a ventilation air circuit (105 Fig. 3) comprising a heat exchanger (100 Fig. 3) which may include one or more heat exchanger elements (200 Fig. 3 para. 0050) in serial flow arrangement with one another relative to a flow of compressed air (99 Fig. 3 which is compressed air from compressor section 21 of Fig. 1, i.e., ventilation air) to a hot section (33 Fig. 3 which comprises the combustion section 26, the turbine or expansion section 31, and the jet exhaust nozzle section 37 per para. 0030). The hot section is analogous to the tail cone structure of Seki in that the tail cone structure is in a jet exhaust nozzle section.
Niergarth teaches a cooling air circuit (circuit from one of coolant supply systems 110 providing cooling air 109 to one of 200 with egressing cooling air 111 flowing from one of 200 in Fig. 3; per para. 0056 one of coolant supply systems 110 may be one or more compressor bleeds which supply the cooling circuit with cooling air) and an air-to- air heat exchanger (one of 200 in Fig. 3).
Niergarth further teaches wherein a ventilation system (Fig. 3) includes an air-to- working fluid heat exchanger (another one of 200 Fig. 3 different than the air-to-air heat exchanger 200; per para. 0056 another one of the systems 110 supplying another one of coolant 109 may be a lubricant system, i.e., an oil system where oil is a working fluid, such that another one of 200 is an air-to-working fluid heat exchanger);
the ventilation air circuit extending through the air-to-working fluid heat exchanger (one of 200 and another one of 200 are shown in series along the ventilation air circuit 105 in Fig. 3 with the ventilation air circuit extending through each); and
a working fluid circuit (per [0056] another one of coolant supply systems 110 providing another one of coolant 109,111 may be a working fluid such as lubricant, i.e., oil) extending from a working fluid source (per [0056] coolant supply system 110 for supplying coolant, i.e., 110 is a coolant source, may be a lubricant system for supplying lubricant, i.e., an oil system for supplying oil which is a working fluid source) through the heat exchanger (oil circuit 109 extends from another one of 110 and through another one of 200 in Fig. 3) to a component of the aircraft propulsion system (per [0059] oil flows through another one of 200 to a bearing assembly of gas turbine engine 10, i.e., an aircraft propulsion system; per [0032] gas turbine engine 10 provides propulsive thrust and [0075] describes operational flight phases such as cruise);
the air-to-working fluid heat exchanger configured to transfer heat energy from the ventilation air into a working fluid flowing within the working fluid circuit (per para. 0038 a flow of another one of coolant 109, i.e., a flow of oil which is a working fluid, to the heat exchanger 100 in another one of 200 is provided in thermal communication with the ventilation air 99 of the ventilation air circuit at the heat exchanger 100 and the flow of oil transfers thermal energy from the ventilation air 99 into the flow of oil to cool
the ventilation air 99; per para. 0056 another one of coolant supply systems 110 providing another one of coolant 109 to another one of 200 of 100 may provide a working fluid such as a flow of lubricant, i.e., oil, as another one of coolant 109, 111, and per para. 0057 each combination of a coolant supply system 110 and each heat exchanger element 200 may define a different heat transfer rate, change in temperature between the ventilation air 99 and each coolant 109, and different pressure drop).
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 Seki in view of Barnett ‘507, Laurello, and Coffinberry wherein the ventilation system includes an air-to-working fluid heat exchanger; the ventilation air circuit extending through the air- to-working fluid heat exchanger; and a working fluid circuit extending through the air-to- working fluid heat exchanger; the air-to-working fluid heat exchanger configured to transfer heat energy from the ventilation air into a working fluid flowing within the working fluid circuit
as taught by Niergarth to assist in having the ventilation air be at a desired outlet temperature, outlet pressure, or both and to maintain a temperature of the oil within an operating constraint relative to a desired outlet temperature and/or pressure of the flow of oil egressed from the heat exchanger which may include a maximum oil temperature such as for a bearing assembly (Niergarth paras. 0056, 0057, 0059).
Regarding claim 10, the invention of Seki in view of Barnett ‘507, Laurello, Coffinberry and Niergarth teaches the working fluid source comprises an oil source configured to direct oil into the working fluid circuit, wherein the working fluid comprises oil (as discussed above in claim 8, Niergarth teaches an oil circuit as the working fluid circuit, and a lubricant system for supplying lubricant, i.e., an oil source, for providing the flow of oil into the working fluid circuit as a coolant).
Claim(s) 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Seki et al. 20220045573 in view of Barnett et al. 20140077507, Laurello et al. 20140311157 and Coffinberry 5305616 as applied to claim 11 above, and further in view of Barnett et al. 20130133336.
Regarding claim 12, Seki in view of Barnett ‘507, Laurello, and Coffinberry teaches all that is claimed above but Seki does not explicitly disclose wherein the electric device is configurable as an electric motor.
Barnett ‘336 teaches an aircraft engine (10 Fig. 1 para. 0017) including an
electric machine (32 Fig. 1) disposed in the tail cone (30 Fig. 1). Barnett ‘336 teaches the electric machine may be configurable as an electric generator to transmit energy from the low pressure shaft and/or as an electric motor to transmit energy to the low pressure shaft (para. 0017).
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 Seki in view of Barnett ‘507, Laurello, Niergarth, Mackin and Linton wherein the electric device is configurable as an electric motor as taught by Barnett ‘336 to transmit energy to the low pressure shaft.
Claim(s) 16-18, 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Seki et al. 20220045573 in view of Niergarth et al. 20190218971 and Ho et al. 20230074116.
Regarding independent claim 16, Seki discloses an assembly for an aircraft propulsion system (Fig. 1 para. 0026), comprising:
a compressor section (31,32 Fig. 1);
a combustor section (33 Fig. 1);
a turbine section (34,35 Fig. 1);
a core flowpath (core flowpath 30 Fig. 1 para. 0031) extending through the compressor section, the combustor section and the turbine section from an inlet (inlet of 31 in Fig. 1) into the core flowpath to an exhaust (39 Fig. 1) from the core flowpath;
an electronic device (G generator in Fig. 1) located in an internal volume (internal volume of tail cone 44 in Fig. 1) of the aircraft propulsion system; and
a ventilation system configured to bleed compressed air from the core flowpath along the compressor section to provide ventilation air (as described in para. 0044, core air duct 63 in Fig. 1 is connected to an air bleed port provided at a portion of the casings of the compressors 31,32 and core air is extracted via the air bleed port), and the
ventilation system configured to direct the ventilation air into the internal volume (bleed air is directed via valve 63V shown in Figs. 1 and 2 into junction box 60 and then into cooling air ducts 61 which extend to 45 within tail cone 44) to ventilate the electronic device (the cooling air ducts 61 supply cooling air into the tail cone 44, and high- temperature electric power cables 51 are accommodated inside the cooling air ducts 61 per para. 0044, and per para. 0044 the cooling air is to keep the generator G and the
high-temperature part electric power cables 51 at or below an acceptable upper limit temperature, i.e., to ventilate the generator),
and the ventilation system including a ventilation air circuit (ventilation air circuit from compressor section 31, 32 to 45 via 63V to 60 to 61 in Fig. 1),
the ventilation air circuit fluidly coupled between a ventilation circuit bleed port and the internal volume (per para. 0044: “core air duct 63 is connected to an air bleed port (not illustrated) provided at a portion of the casings of the compressors (the low pressure compressor 31 and the high pressure compressor 32)”), the ventilation circuit bleed port configured to bleed the compressed air from the core flowpath along the compressor section to provide the ventilation air within the ventilation air circuit (per para. 0044 core air from the compressor, i.e., ventilation air, is extracted via the air bleed port and the compressed air is supplied to cooling air ducts 61 via junction box 60).
Seki is silent regarding
the ventilation system configured to direct the ventilation air through an air-to-air heat exchanger, and the ventilation system including a cooling air circuit and the air-to- air heat exchanger;
the ventilation air circuit extending through the air-to-air heat exchanger;
the cooling air circuit extending through the air-to-air heat exchanger and fluidly coupled to a cooling circuit bleed port, the cooling circuit bleed port configured to bleed additional compressed air from the core flowpath along the compressor section to provide cooling air within the cooling air circuit, the cooling circuit bleed port disposed upstream of the ventilation circuit bleed port along the core flowpath, the cooling air
circuit extending between the cooling circuit bleed port and a cooling circuit outlet, the cooling circuit outlet fluidly coupled with an external environment, and the cooling air circuit fluidly decoupled from the ventilation air circuit; and
the air-to-air heat exchanger configured to transfer heat energy from the ventilation air into the cooling air to cool the ventilation air.
Niergarth teaches a gas turbine engine (10 Fig. 1) including a ventilation air circuit (105 Fig. 3) comprising a heat exchanger (100 Fig. 3) which may include one or more heat exchanger elements (200 Fig. 3 para. 0050) in serial flow arrangement with one another relative to a flow of compressed air (99 Fig. 3 which is compressed air from compressor section 21 of Fig. 1, i.e., ventilation air) to a hot section (33 Fig. 3 which comprises the combustion section 26, the turbine or expansion section 31, and the jet exhaust nozzle section 37 per para. 0030). The hot section is analogous to the tail cone structure of Seki in that the tail cone structure is in a jet exhaust nozzle section.
Niergarth teaches the ventilation system configured to direct the ventilation air through an air-to-air heat exchanger (one of 200 in Fig. 3, per para. 0056 one of coolant supply 110 to one of 200 may be one or more compressor bleeds which supply cooling air to cool the ventilation air 99), and the ventilation system including
a cooling air circuit (circuit from one of coolant supply 110 providing cooling air 109 to one of 200 with egressing cooling air 111 flowing from one of 200 in Fig. 3; per para. 0056 one of coolant supply 110 may be one or more compressor bleeds which supply the cooling circuit with cooling air) and the air-to-air heat exchanger (one of 200 in Fig. 3);
the ventilation air circuit extending through the air-to-air heat exchanger (ventilation circuit 105 of ventilation air 99 from compressor section 21 extends through one of 200 to hot section 33 in Fig. 3);
the cooling air circuit extending through the air-to-air heat exchanger (circuit from 110 providing cooling air 109 to one of 200 with egressing cooling air 111 flowing from one of 200 in Fig. 3) and fluidly coupled to a cooling circuit bleed port (per para. 0056 one of 110 may be one or more compressor bleeds which may supply cooling air to the cooling circuit and necessarily requires a bleed port), the cooling circuit bleed port configured to bleed additional compressed air from the core flowpath along the compressor section to provide cooling air within the cooling air circuit (per para. 0056 one or more compressor bleeds along the compressor section 21 provides the flow of cooling air 109), and the cooling circuit bleed port disposed upstream of the ventilation circuit bleed port along the core flowpath (in order for there to be a thermal transfer from ventilation air 99 to cooling air 109, the cooling circuit bleed port is necessarily upstream of the bleed port providing ventilation air 99 so that compressed air at a lower temperature is bled from the cooling circuit bleed port to enable the cooling air 109 to cool ventilation air 99); and
the air-to-air heat exchanger configured to transfer heat energy from the
ventilation air into the cooling air to cool the ventilation air (per para. 0038 a flow of coolant 109, i.e., cooling air, to the heat exchanger 100 is provided in thermal communication with the ventilation air 99 at the heat exchanger 100 and cooling air transfers thermal energy from the ventilation air 99 into the cooling air to cool the ventilation air 99; and per para. 0057 coolant supply system 110 providing additional
bleed air, i.e., cooling air, as coolant 109 and the air-to-air heat exchanger of one of 200 included in 100 may define a heat transfer rate, change in temperature between the compressed air 99 which is the ventilation air and the coolant 109 which is cooling air).
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 Seki wherein the ventilation system is configured to direct the ventilation air through an air-to-air heat exchanger, and the ventilation system including a cooling air circuit and the air-to-air heat exchanger; the ventilation air circuit extending through the air-to-air heat exchanger; and the cooling air circuit extending through the air-to-air heat exchanger and fluidly coupled to a cooling circuit bleed port, the cooling circuit bleed port configured to bleed additional compressed air from the core flowpath along the compressor section to provide cooling air within the cooling air circuit, and the cooling circuit bleed port disposed upstream of the ventilation circuit bleed port along the core flowpath; and the air-to-air heat exchanger configured to transfer heat energy from the ventilation air into the cooling air to cool the ventilation air as taught by Niergarth to assist in having the ventilation air be at a desired outlet temperature, outlet pressure, or both and to maintain a temperature of bleed cooling air within an operating constraint relative to a desired outlet temperature and/or pressure of the flow of bleed cooling air egressed from the air-to-air heat exchanger (Niergarth paras. 0056, 0057 and 0059).
Seki in view of Niergarth does not explicitly teach the cooling air circuit extending between the cooling circuit bleed port and a cooling circuit outlet, the cooling circuit outlet fluidly coupled with an external environment, and the cooling air circuit fluidly decoupled from the ventilation air circuit.
Niergarth further teaches the egressing flow of cooling air 111 from air-to-air heat exchanger 200 which is compressor bleed air is further used for one or more other systems such as environmental control systems, clearance control systems, etc. per [0059].
Ho teaches an environmental control system ECS for an aircraft per [0001]. The ECS pack 20 is used in an aircraft application with the first medium A1 being fresh or outside ambient air and ECS 20 provides a conditioned form of only the first medium of fresh air to the aircraft per [0030], with 24 representing loads of the aircraft such as a cabin of the aircraft in Fig. 1. The ECS pack 20 is configured to extract work from a second medium A2 and the pressurized air A2 can be utilized by the ECS pack 20 to achieve certain operations per [0031]. The ECS pack 20 in Fig. 1 is configured to receive second medium A2 at inlet 26 which is bleed air from a high pressure compressor spool of an engine per [0031]. In the first mode of operation, valve V1 is opened to draw the high pressure, hot second medium A2 of bleed air from the turbine engine and bleed air is configured to pass through second heat exchanger 32 within which the high pressure, high temperature second bleed air is cooled via a heat exchange relationship with the ram air flow, then from second heat exchanger 32, the bleed air enters the power turbine 46 via a nozzle and the high pressure, high temperature bleed air is expanded across the power turbine 46 and work extracted from the hot high pressure air and extracted work drives the compressor 42 via shaft 50
which also drives fan 48, which is used to move air through the heat exchangers 30, 32, via a ram air duct 34 and then the bleed air output from the power turbine 46 may be exhausted overboard into the ambient atmosphere, i.e., the bleed air circuit outlet is fluidly coupled with an external environment.
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 Seki in view of Niergarth and Ho to have the cooling air circuit extending from the cooling circuit bleed port to the air-to- air heat exchanger and then having the cooling air egressed from the air-to-air heat exchanger, which is compressor bleed air in the cooling air circuit, configured to be provided to an environmental control system as taught by Niergarth as combining prior art elements according to known methods to yield predictable results, in this case utilizing a cooling flow of bleed air egressed from an air-to-air heat exchanger, the air-to- air heat exchanger using compressor bleed air for both flows through the air-to-air heat exchanger, in other systems of the aircraft engine or aircraft including in an environmental control system as in the environmental control system taught by Ho.
in this case utilizing a cooling bleed air egressed from an air-to-air heat exchanger with compressor bleed air for both flows in the air-to-air heat exchanger in other systems of the aircraft engine or aircraft
"The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results. [W]hen a patent 'simply
arranges old elements with each performing the same function it had been known to perform' and yields no more than one would expect from such an arrangement, the combination is obvious." KSR at 1395-66 (citing Sakraida v. AG Pro, Inc., 425 U.S. 273, 282 (1976)).
It would have also been obvious to have the bleed air circuit outlet which is the cooling circuit outlet in the invention of Seki in view of Niergarth fluidly coupled with an external environment as taught by Ho to utilize the egressed bleed air in the cooling air circuit to provide work to the ECS system to condition fresh air for the aircraft cabin and provide only the conditioned fresh air to the cabin and then exhaust the used bleed air to the external environment to provide cabin pressurization and cooling of fresh air at a high fuel burn efficiency [0029]. Therefore, Seki in view of Niergarth and Ho teaches the cooling air circuit is fluidly decoupled from the ventilation air circuit as claimed since the ventilation air is directed to the tail cone to cool a generator and the cooling air is directed to the ECS and then exhausted to the external environment.
Regarding claim 17, Seki in view of Niergarth and Ho teaches all that is claimed above and Seki further discloses wherein the internal volume is disposed radially inboard of the core flowpath (internal volume of 44 is radially inboard of core flowpath 30 Fig. 1).
Regarding claim 18, Seki in view of Niergarth and Ho teaches all that is claimed above and Seki further discloses
a tail cone structure (44 Fig. 1);
the internal volume at least partially formed by the tail cone structure (internal volume is at least partially formed by 44 in Fig. 1).
Regarding claim 21, Seki in view of Niergarth and Ho teaches all that is claimed above and Seki further discloses
the compressor section comprises a low pressure compressor section (31 Fig. 1) and a high pressure compressor section (32 Fig. 1); and
the ventilation system is configured to bleed the compressed air from the core flowpath along a downstream end of the high pressure compressor section (as seen in annotated Fig. 1, compressed air is bled from a downstream end of 32) to provide the ventilation air.
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Claim(s) 19-20 and 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Seki et al. 20220045573 in view of Niergarth et al. 20190218971, and Coffinberry 5305616.
Regarding independent claim 19, Seki discloses an assembly for an aircraft propulsion system (Fig. 1 para. 0026), comprising:
a compressor section (31,32 Fig. 1);
a combustor section (33 Fig. 1);
a turbine section (34,35 Fig. 1);
a core flowpath (core flowpath 30 Fig. 1 para. 0031) extending through the compressor section, the combustor section and the turbine section from an inlet (inlet of 31 in Fig. 1) into the core flowpath to an exhaust (39 Fig. 1) from the core flowpath;
an electronic device (G generator in Fig. 1) located in an internal volume (internal volume of tail cone 44 in Fig. 1) of the aircraft propulsion system; and
a ventilation system configured to bleed compressed air from the core flowpath along the compressor section to provide ventilation air (as described in para. 0044, core air duct 63 in Fig. 1 is connected to an air bleed port provided at a portion of the casings of the compressors 31,32 and core air is extracted via the air bleed port), and the ventilation system configured to direct the ventilation air into the internal volume (bleed air is directed via valve 63V shown in Figs. 1 and 2 into junction box 60 and then into cooling air ducts 61 which extend to 45 within tail cone 44) to ventilate the electronic device (the cooling air ducts 61 supply cooling air into the tail cone 44, and high-temperature electric power cables 51 are accommodated inside the cooling air ducts 61 per para. 0044, and per para. 0044 the cooling air is to keep the generator G and the high-temperature part electric power cables 51 at or below an acceptable upper limit temperature, i.e., to ventilate the generator),
and the ventilation system including a ventilation air circuit (ventilation air circuit from compressor section 31, 32 to 45 via 63V to 60 to 61 in Fig. 1),
the ventilation air circuit fluidly coupled between a ventilation circuit bleed port and the internal volume (per para. 0044: “core air duct 63 is connected to an air bleed port (not illustrated) provided at a portion of the casings of the compressors (the low pressure compressor 31 and the high pressure compressor 32), the ventilation circuit bleed port configured to bleed the compressed air from the core flowpath along the compressor section to provide the ventilation air within the ventilation air circuit (per para. 0044 core air from the compressor, i.e., ventilation air, is extracted via the air bleed port and the compressed air is supplied to cooling air ducts 61 via junction box 60).
Seki is silent regarding
the ventilation system configured to direct the ventilation air through an air-to-air heat exchanger and an air-to-working fluid heat exchanger, the ventilation system including a cooling air circuit, a working fluid circuit, the air-to-air heat exchanger and the air-to-working fluid heat exchanger;
the ventilation air circuit extending through the air-to-air heat exchanger and the air-to-working fluid heat exchanger;
the cooling air circuit extending through the air-to-air heat exchanger and fluidly coupled to a cooling circuit bleed port, the cooling circuit bleed port configured to bleed additional compressed air from the core flowpath along the compressor section to provide cooling air within the cooling air circuit, the cooling air circuit extending between the cooling circuit bleed port and a cooling circuit outlet, and the cooling circuit outlet fluidly coupled with a bypass flowpath;
the working fluid circuit extending through the air-to-working fluid heat exchanger, and the working fluid circuit fluidly independent of the ventilation air circuit; and
the air-to-working fluid heat exchanger configured to transfer heat energy from the ventilation air into a liquid working fluid flowing within the working fluid circuit to cool the ventilation air.
Niergarth teaches a gas turbine engine (10 Fig. 1) with a ventilation system (Fig. 3) including a ventilation air circuit (105 Fig. 3) comprising a heat exchanger (100 Fig. 3).
Niergarth teaches the ventilation system configured to direct the ventilation air through an air-to-air heat exchanger and an air-to-working fluid heat exchanger (heat exchanger 100 may include heat exchanger elements 200 which may include one of 200, i.e., as an air-to-air heat exchanger since per para. 0056 coolant 109 may be one or more compressor bleeds, and another one of 200, i.e., as an air-to-working fluid heat exchanger since per para. 0056 coolant 109 may be fuel which is a working fluid, with each 200 arranged in serial flow arrangement with one another relative to a flow of compressed air 99 as shown in Fig. 3 and per para. 0050, with 99 being compressed air from compressor section 21 of Fig. 1, i.e., ventilation air, such that ventilation air is
directed through an air-to-air heat exchanger and an air-to-working fluid heat exchanger since ventilation air 99 flows through each of 200 in Fig. 3) to a hot section (33 Fig. 3 which comprises the combustion section 26, the turbine or expansion section 31, and the jet exhaust nozzle section 37 per para. 0030). The hot section 33 is analogous to the tail cone structure of Seki in that the tail cone structure is in a jet exhaust nozzle section.
Niergarth teaches the ventilation system (Fig. 3) including a cooling air circuit (circuit from one of coolant supply 110 providing cooling air 109 to one of 200 with egressing cooling air 111 flowing from one of 200 in Fig. 3; per para. 0056 one of coolant supply 110 may be one or more compressor bleeds which supply the cooling circuit with cooling air), a working fluid circuit (per para. 0056 another one of coolant supply systems 110 providing coolant 109,111 may be a fuel system supplying fuel, i.e., a working fluid, flowing through a working fluid circuit through another one of 200 in Fig. 3), the air-to-air heat exchanger (one of heat exchanger elements 200 in Fig. 3; per para. 0056 one of coolant supply 110 may be one or more compressor bleeds which supply cooling air) and the air-to-working fluid heat exchanger (another one of 200 in Fig. 3 with fuel as the coolant);
a ventilation air circuit extending through the air-to-air heat exchanger and the air-to-working fluid heat exchanger (a ventilation air circuit 105 of ventilation air 99 extends from compressor section 21 as a flow of ventilation air 99 flowing in series through each of 200 including the air-to-air heat exchanger and the air-to-working fluid heat exchanger to hot section 33 in Fig. 3);
the cooling air circuit extending through the air-to-air heat exchanger (circuit from 110 providing cooling air 109 to one of 200 with egressing cooling air 111 flowing from one of 200 in Fig. 3) and fluidly coupled to a cooling circuit bleed port (per para. 0056 one of 110 may be one or more compressor bleeds which may supply cooling air to the cooling circuit and necessarily requires a bleed port), the cooling circuit bleed port configured to bleed additional compressed air from the core flowpath along the compressor section to provide cooling air within the cooling air circuit (per para. 0056 one or more compressor bleeds along the compressor section 21 provides the flow of cooling air 109),
the working fluid circuit extending through the air-to-working fluid heat exchanger (the working fluid circuit extends from another one of 110 as a flow of working fluid 109 which is fuel through another one of 200 in Fig. 3); and
the air-to-working fluid heat exchanger configured to transfer heat energy from the ventilation air into a liquid working fluid (liquid fuel per para. 0032, i.e., a liquid working fluid) flowing within the working fluid circuit (per para. 0038 a flow of another one of coolant 109, i.e., liquid fuel as liquid working fluid, to the heat exchanger 100 including another one of 200, which is the air-to-working fluid heat exchanger, is provided in thermal communication with the ventilation air 99 at the heat exchanger 100 and the liquid fuel transfers thermal energy from the ventilation air 99 into the liquid fuel to cool the ventilation air 99, and heat the flow of fuel which may define an operating constraint relative to a desired outlet or discharge temperature/pressure of the flow of fuel egressed from the air-to-working fluid heat exchanger as another one of 200 thereof such as a maximum fuel temperature per para. 0059; per para. 0056 another one of coolant supply systems 110 providing another one of coolant 109 to another one of 200 of 100 may provide a working fluid such as a flow fuel as the coolant 109, 111, which may be a liquid fuel per para. 0032, and per para. 0057 each combination of one of and another one of the coolant supply system 110 and each of one of and another one of heat exchanger element 200 may define a different heat transfer rate, change in temperature between the ventilation air 99 and each coolant 109, and different pressure drop).
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 Seki to have the ventilation system configured to direct the ventilation air through an air-to-air heat exchanger and an air-to-working fluid heat exchanger, the ventilation system including a cooling air circuit, a working fluid circuit, the air-to-air heat exchanger and the air-to-working fluid heat exchanger; the ventilation air circuit extending through the air-to-air heat exchanger and the air-to-working fluid heat exchanger; the cooling air circuit extending through the air-to-air heat exchanger and fluidly coupled to a cooling circuit bleed port, the cooling circuit bleed port configured to bleed additional compressed air from the flowpath along the compressor section to provide cooling air within the cooling air circuit; the working fluid circuit extending through the air-to-working fluid heat exchanger, and the working fluid circuit fluidly independent of the ventilation air circuit; and the air-to-working fluid heat exchanger configured to transfer heat energy from the ventilation air into a liquid working fluid flowing within the working fluid circuit to cool the ventilation air as taught by Niergarth to assist in having the ventilation air be at a desired outlet temperature, outlet pressure, or both, to maintain a temperature of bleed cooling air within an operating constraint relative to a desired outlet temperature and/or pressure of the flow of bleed cooling air egressed from the air-to-air heat exchanger and to maintain a temperature of the fuel within an operating constraint relative to a desired outlet temperature and/or pressure of the flow of fuel egressed from the heat exchanger such as within a maximum fuel temperature at a combustor fuel manifold at the combustion section (Niergarth paras. 0056, 0057 and 0059).
Seki in view of Niergarth does not explicitly teach the cooling air circuit extending between the cooling circuit bleed port and a cooling circuit outlet, and the cooling circuit outlet fluidly coupled with a bypass flowpath.
Coffinberry teaches a gas turbine engine (10 Fig. 1) with a cooling system 110 with an air-to-air heat exchanger 130 in Fig. 2 which has an inlet 144 and an outlet 146 for a first airflow, i.e., a cooling air circuit, providing cooling to heat exchanger 130 and has an inlet 148 and an outlet 150 for a second airflow receiving cooling from heat exchanger 130, where the first airflow is lower in temperature and pressure than the second airflow and the first airflow is preferably discharged into the fan bypass duct 38 with an aft component of velocity (col 3 lines 62-68 to col 4 lines 1-13), i.e., cooling circuit outlet 146 is fluidly coupled with a bypass flowpath.
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 Seki in view of Niergarth to have the cooling air circuit extending between the cooling circuit bleed port and a cooling circuit outlet, the cooling circuit outlet fluidly coupled with a bypass flowpath as taught by Coffinberry for thrust recovery by adding the cooling air to the
bypass airflow from the fan which provides most of the engine thrust for the aircraft (col 1 lines 41-43).
Regarding claim 20, Seki in view of Niergarth, and Coffinberry teaches all that is claimed above and Seki further discloses
a tail cone structure (44 Fig. 1);
the electronic device located within the tail cone structure (generator G is located within 44 in Fig. 1).
Regarding claim 22, Seki in view of Niergarth, and Coffinberry teaches all that is claimed above and Seki further discloses
the compressor section comprises a low pressure compressor section (31 Fig. 1) and a high pressure compressor section (32 Fig. 1); and
the ventilation system is configured to bleed the compressed air from the core flowpath along a downstream stage of the high pressure compressor section (as shown in annotated Fig. 1 compressed air is bled from a downstream stage of 32) to provide the ventilation air.
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Response to Arguments
Applicant's arguments filed 01/06/2026 have been fully considered but they are not persuasive. Applicant argues on page 13 of Remarks that there is no disclosure, teaching or suggestion in Laurello that the alleged ventilation system of Laurello could be suitably modified to "direct the ventilation air through the air-to-air heat exchanger and into an internal volume in the tail cone structure" as recited in claim 1. However, in the Non-Final rejection and in the current Final rejection of claim 1, it is shown that base reference Seki already teaches directing ventilation air into an internal volume in the tail cone structure to cool a generator within the internal volume and Barnett teaches it is known to have the ventilation air pass through a heat exchanger before the ventilation air is provided to cool the generator. Laurello teaches an air-to-air heat exchanger using cooling air bled from the high pressure compressor five or more stages upstream of a stage from which ventilation air is bled from the high pressure compressor and the cooling air cools the ventilation air within the air-to-air heat exchanger and the ventilation air is used to cool a component of a hot section of the gas turbine engine. Seki in view of Barnett is modified in view of the teachings of Laurello. Modifying Laurello is not required or proposed in the rejection of claim 1.
Applicant argues on page 17 of Remarks regarding the rejection of claim 16 that Niergarth discloses the alleged ventilation system is configured to inject compressed air within a core flowpath (i.e., areas through which combustion gases 86 are formed and flow). However, Niergarth actually discloses in [0028] that the cooled cooling fluid defining the compressed air, i.e., ventilation air, provides a desired outlet temperature and outlet pressure such as to provide cooling to one or more components within a secondary flowpath of a hot section of the engine (e.g., blades, vanes, casing, shrouds, within a combustion section 26, turbine or expansion section 31, or exhaust section 37 of the heat engine 10. The ventilation air is injected into a secondary flowpath within a hot section component, not into the core flowpath. Combustion gases flow through the hot section of the gas turbine engine along the core flowpath such that the hot section components need to be cooled.
Applicant argues there is no disclosure, teaching or suggestion in Niergarth that the alleged ventilation system could be modified to include a "ventilation air circuit extending through the air-to-air heat exchanger and fluidly coupled between a ventilation circuit bleed port and the internal volume, the ventilation circuit bleed port configured to bleed the compressed air from the flowpath along the compressor section to provide the ventilation air within the ventilation air circuit" as recited in claim 16. However, base reference Seki already teaches the ventilation air circuit fluidly coupled between a ventilation circuit bleed port and the internal volume, the ventilation circuit bleed port configured to bleed the compressed air from the flowpath along the compressor section to provide ventilation air within the ventilation air circuit, and Seki is modified in view of the teaching of Niergarth to have the ventilation air circuit extend through an air-to-air heat exchanger. The rejection of claim 16 does not describe or require modifying the invention of Niergarth.
Applicant argues on page 21 of Remarks the same argument regarding the rejection of claim 19 and prior art Niergarth. The rejection of claim 19 does not describe or require modifying the invention of Niergarth. The rejection of claim 19 describes modifying the invention of Seki in view of the teachings of Niergarth.
Applicant does not provide arguments regarding the dependent claims or new claim 23.
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
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