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 in response to the correspondence received on 12/12/2025.
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 6/12/2025 has been entered.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
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 1, and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Robic (US 2017/0226934 A1) in view Hannwacker (US 20170248315), West (EP 967676), Rainville (US 2005/0095474 Al), Butler (US 2023/0120297) Mackin (20130187007).
Regarding claim 1, Robic teaches:
1. (Currently amended) An anti-stall system (optimizing the surge margin of the compressor [0005]) for an aircraft ([0001]), the anti-stall system comprising:
a propulsion system including, in serial flow relationship, a low-pressure compressor (1, Figs. 1-5), a high-pressure compressor (2, Fig. 1-5), and a combustion section (inter alia, 3), wherein the propulsion system further comprises, a fuel cell assembly (9, SOFC Fig 2), an electric bus (“An electric motor 8 is supplied with electric current either directly by the electricity generator 7 or by the storage device 9,” [0038], describes an electric bus), an electric machine (inter alia, 7, 8), and at least one shaft (10), and wherein the combustion section comprises a combustor (3, Fig 2), and wherein the electric bus is electrically coupled to the fuel cell assembly (SOFC in 9, Fig 2) and the electric machine (arrows in between 9 and 7 and 8 in Fig 2);
a sensor configured to sense (“current surge that can be detected and the value of the signal” [0072] – the teaching of a sensor is implicit since this teaches to detect and produce a signal) data indicative of an operating parameter indicative of a compressor stall condition of at least one of the low-pressure compressor or the high-pressure compressor (referring to Fig. 6 “This diagram conventionally gives the change in the compression ratio delivered by the compressor as a function of the flow rate passing through it and is parameterized according to its rotation speed, which is expressed as a percentage of the rotation speed at take-off. According to the operating parameters of the engine, the point representing the operation of the compressor moves in this diagram while remaining below the surge line A, which for its part is a characteristic of the compressor” [0046] – the surge line A represents the compressor stall, and the compressor rotational speed is the operating parameter indicative of a compressor stall); and
a controller (FADEC [0072]) electronically coupled to the sensor (“a current surge that can be detected and the value of the signal of which with respect to defined thresholds can serve to adjust the balances between the gas generator and the electric motor by varying the control laws of the FADEC system” [0072]), wherein the controller is configured to:
receive the data indicative of the operating parameter indicative of the compressor stall condition (“a current surge that can be detected and the value of the signal of which with respect to defined thresholds” [0072]), wherein receiving the data indicative of the operating parameter comprises receiving data indicative of one or more of a flame in the combustor, rotational speed (rotational speed, as discussed above) of the at least one shaft (shaft connected to the compressor, as discussed above), or a combustion engine load; and
Robic teaches the combustor but is silent about:
the combustor including an inner liner, an outer liner, and a combustion chamber defined therebetween,
However, Hannwacker teaches a combustor assembly (title) for a turbofan engine (Fig. 1), and:
a combustor including an inner liner (Hannwacker 114, Fig 2 [0027]), an outer liner (Hannwacker 116, Fig 2 [0027]), and a combustion chamber defined therebetween (108, Fig 2),
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Robic with Hannawacker’s structure as discussed above in to provide a combustor with an inner liner and an outer liner in order to facilitate “a combustor assembly capable of effectively joining multiple components formed of CMC materials” As taught by Hannwacker [0005].
Robic teaches the fuel cell as discussed above, but Robic in view of Hannwacker is silent about:
wherein the fuel cell assembly is integrated with the inner liner or the outer liner and is in fluid communication with the combustion chamber.
However, West teaches a jet engine (title), and:
wherein the fuel cell assembly (33, Fig 2, [0009]) is integrated with the inner liner or the outer liner and is in fluid communication with the combustion chamber (“A number of fuel cell tiles 33 are arranged in the wall 322 of the combustion chamber” [0009]);
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Robic in view of Hannwacker with fuel cells in the liner of the combustor as taught by West because “this completely eliminates moving parts from the electricity generation process and allows the components associated with electricity generation to be disposed within the housing of the engine” [0008].
Robic in view of Hannwacker and West, is silent about:
execute an anti-stall action responsive to the data indicative of the operating parameter indicative of the compressor stall condition if the operating parameter has achieved a compression stall condition threshold, wherein executing the anti-stall action includes increasing or decreasing at least one fuel cell parameter of the fuel cell assembly.
However, Rainville teaches compressor surge detection system (Title), where the “controller receives a signal from the mass flow meter indicative of the reverse flow” Abstract); and
execute an anti-stall action responsive to the data indicative of the operating parameter indicative of the compressor stall condition if the operating parameter has achieved a compression stall condition threshold, wherein executing the anti-stall action includes increasing or decreasing at least one fuel cell parameter of the fuel cell assembly (“The controller controls a motor driving the compressor and a back pressure valve at the cathode exhaust of the fuel cell module to control the pressure in the fuel cell module to remove the surge condition.” Abstract).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to provide Robic in view of Hannwacker and West with the teachings of Rainville in order to measure “the airflow through the compressor, and provides an indication of a reverse airflow through the compressor for surge protection” as taught by Rainville (Abstract).
Robic in view of Hannwacker, West and Rainville teaches the low-pressure compressor, the high-pressure compressor, but is silent about:
A secondary compressor
wherein the second compressor is in airflow communication with the fuel cell assembly
However, Butler teaches an aircraft propulsion system, with a low-pressure compressor (410, Fig 4), a high-pressure compressor (411, Fig. 4)], and:
a secondary compressor (412,Fig. 4)
wherein the second compressor is in airflow communication with the fuel cell assembly (452, Fig. 4).
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Robic in view of Hannwacker, West, and Rainville with Butler's teachings discussed above, in order to “provide air to an input port 455 of the PEM fuel cell system 452” as taught by Butler [0024].
Robic in view of Hannwacker, West, Rainville and Butler teaches the low-pressure compressor, the high-pressure compressor, but is silent about:
wherein the secondary compressor is fluidly coupled to the low-pressure compressor via a first bleed flow path to receive a first bleed flow from the low-pressure compressor, wherein the secondary compressor is fluidly coupled to the high-pressure compressor via a second bleed flow path to receive a second bleed flow from the high-pressure compressor, wherein the second compressor is in airflow communication to provide at least one of the first bleed flow or the second bleed flow
However, Mackin teaches an aircraft engine (abstract, Fig. 7), comprising a high pressure compressor and a low pressure compressor (212, 210), a secondary compressor (232, Fig. 7, [0065]), and:
wherein the secondary compressor is fluidly coupled to the low-pressure compressor (210) via a first bleed flow path (via, inter alia, 236) to receive a first bleed flow from the low-pressure compressor (from 210 to 232, Fig. 7), wherein the secondary compressor is fluidly coupled to the high-pressure compressor via a second bleed flow path (image below) to receive a second bleed flow from the high-pressure compressor (from 212 to 232), wherein the second compressor is in airflow communication to provide at least one of the first bleed flow or the second bleed flow (Fig. 7).
It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Robic in view of Hannwacker, West, Rainville and Buttler with Mackin's structure discussed above, such that the secondary compressor is fluidly coupled to the low-pressure compressor via a first bleed flow path to receive a first bleed flow from the low-pressure compressor, wherein the secondary compressor is fluidly coupled to the high-pressure compressor via a second bleed flow path to receive a second bleed flow from the high-pressure compressor, wherein the second compressor is in airflow communication with the fuel cell assembly to provide at least one of the first bleed flow or the second bleed flow to the fuel cell assembly, in order to provide “a dual inlet source to enable the compressor 232 to receive bleed air from a high-pressure source (e.g., the high-pressure compressor 212) during a first period of operation (e.g., when the engine 700 is idle) and enable the compressor 232 to draw bleed air from a low-pressure source during a second period of operation (e.g., during cruising altitudes)” as taught by Mackin [0065].
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Regarding claim 5, Robic in view of Hannwacker, West, Rainville, Butler and Mackin teaches the invention as discussed for claim 1. Robic further teaches:
wherein receiving the data indicative of the operating parameter comprises receiving sensor data of a change in rotational speed of the at least one shaft (the data from the sensors was already discussed above; the change in speed is taught by “it allows electrical coupling of the two shafts in descent (taking from the LP shaft and adding to the HP shaft in order to avoid chamber extinctions),it allows coupling of the two shafts for better control of the acceleration of the two bodies and better management of their rotation speeds” [0070] and “a current surge that can be detected and the value of the signal of which with respect to defined thresholds can serve to adjust the balances between the gas generator and the electric motor by varying the control laws of the FADEC system” [0072] ),
wherein adjusting the at least one fuel cell parameter includes adjusting the electric machine based on an acceleration of the at least one shaft (“a current surge that can be detected and the value of the signal of which with respect to defined thresholds can serve to adjust the balances between the gas generator and the electric motor by varying the control laws of the FADEC system” [0072], and “an electric motor forming a device for applying mechanical power to at least one of said rotating shafts, a device for drawing power from at least one of said rotating shafts” [0006] and [0007]. Also see [0065-0072]).
Claims 2-4, 6-10 are rejected under 35 U.S.C. 103 as being unpatentable over Robic (US 2017/0226934 A1) in view Hannwacker (US 20170248315), West (EP 967676), Rainville (US 2005/0095474 Al), and Butler 20230120297 and further in view of “Stall/surge dynamics of a multi-stage air compressor in response to a load transient of a hybrid solid oxide fuel cell-gas turbine system” by Mohammad Ali Azizi, Jacob Brouwer (hereafter Azizi).
Regarding claim 2, Robic in view of Hannwacker, West, Rainville and Butler teaches the invention as discussed for claim 1. Robic in view of Hannwacker, West, Rainville, and Butler, as discussed so far, silent about:
wherein the at least one fuel cell parameter includes:
a current output of the fuel cell assembly;
a fuel utilization of the fuel cell assembly;
an air to fuel ratio of a fuel cell stack of the fuel cell assembly;
any combination thereof.
However, Azizi teaches an academic research about stall/surge dynamics of a multi-stage air compressor of a hybrid solid oxide fuel cell-gas turbine system (Title), and:
wherein the at least one fuel cell parameter includes (Azizi teaches compressor surges can result from lack of shutdown control strategy and further teaches control parameters (pp 409 last paragraph and page 410 first paragraph)):
a current output of the fuel cell assembly (Azizi page 410, 1st column, 1st paragraph “System power was controlled by manipulating the SOFC current”);
a fuel utilization of the fuel cell assembly (Azizi page 410, 1st column, 1st paragraph “, fuel utilization was controlled by manipulating the fuel flow”);
an air to fuel ratio of a fuel cell stack of the fuel cell assembly (Azizi page 410, 1st column, 1st paragraph “fuel utilization was controlled by manipulating the fuel flow, air flow was controlled by manipulating the shaft speed and cell temperature was controlled by adjustment of the air flow setpoint”); or
any combination thereof.
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 Robic in view of Hannwacker, West, Rainville, Butler and Mackin to incorporate Azizi’s structure as discussed above in order enable “control strategies […] to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor” as taught by Azizi (Azizi, Abstract) and provide a higher efficiency fuel-cell-gas-turbine hybrid system (Azizi, p.410, “Fig. 1 shows the model of a 4 MW hybrid power generation system that has been previously developed at the National Fuel Cell Research Center (NFCRC) at the University of California, Irvine using MATLAB/Simulink tools. This model was used to show that such systems, when properly designed and controlled, possess higher efficiency than previously tested SOFC-GT systems in power generation applications”).
Regarding claim 3, Robic in view of Hannwacker, West, Rainville, Butler and Mackin teaches the invention as discussed for claim 1. Robic further teaches:
wherein the fuel cell assembly comprises a fuel cell (Fig 3 SOFC in element 9, [0034]).
Robic in view of Hannwacker, West, Rainville and Butler, as discussed so far, is silent about:
defining an outlet positioned to remove output products from the fuel cell and provide the output products to the combustor, wherein a combustor output power of the combustor is controlled by adjusting the at least one fuel cell operating parameter.
However, Azizi teaches:
a fuel cell assembly comprises a fuel cell (Azizi, Fig 1, anode and cathode) defining an outlet (Azizi, Fig 1, from the anode) positioned to remove output products from the fuel cell and provide the output products to the combustor (Azizi Fig 1, shows flow from the Anode to the Combustor on the right side of the drawing) wherein a combustor output power of the combustor is controlled by adjusting the at least one fuel cell operating parameter (Azizi page 409, 2nd column, 3rd paragraph and page 410 1st paragraph: “fuel utilization, fuel cell and GT power, shaft speed, compressor mass flow and temperatures in the cycle were considered as the controlled response to the fuel cell voltage increase” – GT power, shaft speed, compressor flow are all directly correlated to combustor power output).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to provide Robic in view of Hannwacker, West, Rainville, Butler and Mackin with Azizi’s structure as discussed above in order to enable “control strategies […] to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor” as taught by Azizi (Azizi, Abstract) and provide a higher efficiency fuel-cell-gas-turbine hybrid system (Azizi, p.410, “Fig. 1 shows the model of a 4 MW hybrid power generation system that has been previously developed at the National Fuel Cell Research Center (NFCRC) at the University of California, Irvine using MATLAB/Simulink tools. This model was used to show that such systems, when properly designed and controlled, possess higher efficiency than previously tested SOFC-GT systems in power generation applications”).
Regarding claim 4, Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi teaches the invention as discussed for claim 3. Robic further teaches:
wherein the electric machine (Robic Fig 2, elements 7 and 8) is rotatable with the at least one shaft (Reducers 17 and 18 rotate with the shaft connecting the compressors and turbines in Fig 2), wherein adjusting the at least one fuel cell parameter (electrical power being provided to the electrical motor [0006-0007]) comprises adjusting fuel cell power output to the electric machine (Fig 2 shows a fuel cell SOFC element 9, and W6 represents the flow of energy from element 9 into the electric motor 8. Since “electrical energy can […] be sent directly, by an electric power-ejection motor 8, to one of the shafts of the turbojet engine” [0033]; electrical motor applies additional power to the rotating shafts, moving the compressor away from a surge line [0006-0008] when the shaft accelerates).
Regarding claim 6, Robic in view of Hannwacker, West, Rainville, Butler and Mackin teaches the invention as discussed for claim 1. Robic in view of Hannwacker, West, Rainville, Butler and Mackin, is silent about:
wherein adjusting the at least one fuel cell parameter includes increasing a pressure, a flow rate, or both of the at least one bypass flow from the compressor to the fuel cell assembly.
However, Azizi teaches:
wherein adjusting the at least one fuel cell parameter includes increasing a pressure, a flow rate, or both of at least one bypass flow (Azizi Fig 1 shows a “heater bypass” from the Compressor going through a mixer and into the Cathode) from the compressor to the fuel cell assembly (Azizi page 410, 1st column, ln 2: “System power was controlled by manipulating […] air flow was controlled by manipulating the shaft speed and cell temperature was controlled by adjustment of the air flow setpoint”).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to provide Robic in view of Hannwacker, West, Rainville, Butler and Mackin with Azizi’s structure as discussed above in order enable “control strategies […] to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor” as taught by Azizi (Azizi, Abstract) and provide a higher efficiency fuel-cell-gas-turbine hybrid system (Azizi, p.410, “Fig. 1 shows the model of a 4 MW hybrid power generation system that has been previously developed at the National Fuel Cell Research Center (NFCRC) at the University of California, Irvine using MATLAB/Simulink tools. This model was used to show that such systems, when properly designed and controlled, possess higher efficiency than previously tested SOFC-GT systems in power generation applications”).
Regarding claim 7, Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi teaches the invention as discussed for claim 6. Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi as discussed so far, is silent about:
wherein adjusting the at least one fuel cell parameter includes increasing the pressure of the at least one bypass flow to be greater than a combustion chamber pressure.
However, Azizi teaches:
The anti-stall system of claim 6, wherein adjusting the at least one fuel cell parameter includes increasing the pressure of the at least one bypass flow to be greater than a combustion chamber pressure (Azizi fig 1 shows a flow path “Heater Bypass” through the left-most mixer, to the Cathode and then to the combustor; the pressure upstream of the Combustor (which includes the Heater Bypass section) must be higher than the combustor’s pressure in order for flow to occur).
Regarding claim 8, Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi teaches the invention as discussed so far (including the at least one bypass flow being compressed air from the compressor that is communicated to the fuel cell, and the secondary compressor.
As already discussed above, Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi teaches:
communicate at least one of the first bleed flow or the second bleed flow to the fuel cell assembly (as already discussed).
Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi, as discussed so far, is silent about:
wherein the secondary compressor is configured to:
receive at least one of the first bleed flow or the second bleed flow at a secondary compressor inlet of the secondary compressor;
increase the pressure of at least one of the first bleed flow or the second bleed flow; and
a secondary compressor outlet of the secondary compressor.
However, Mackin teaches
wherein the secondary compressor is configured to:
receive at least one of the first bleed flow or the second bleed flow at a secondary compressor inlet of the secondary compressor (inlet where first bleed flow path or second bleed flow path enter 232, Image below);
increase the pressure of at least one of the first bleed flow or the second bleed flow (the turbo-compressor employed by the examples disclosed herein can boost the pressure of the bleed air, Abstract); and
a secondary compressor outlet of the secondary compressor (outlet indicated in the image below).
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Regarding claim 9, Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi teaches the invention as discussed for claim 8.
Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi, as discussed so far, is silent about:
wherein the secondary compressor is further configured to receive a motive force from the propulsion system
However, Mackin teaches:
wherein the secondary compressor is further configured to receive a motive force from the propulsion system (“the turbine 234 receives the bleed air to operate the compressor 232 via the shaft 260” [0066], Fig. 7).
Regarding claim 10, Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi teaches the invention as discussed for claim 8. Robic further teaches:
wherein the secondary compressor is configured to receive power from the fuel cell (“fuel cell” [0034]) assembly (Fig 2 shows SOFC in element 9, “The mechanical power delivered to the LP shaft 10 is designated by the reference sign w1and that delivered to the HP shaft 20 is designated by the reference sign w2” [0038]; “The diagram in FIG. 2 attempts to illustrate all conceivable cases of drawing power from the shafts of a twin-spool bypass turbojet engine” [0032] and Fig 5 further helps illustrate the process of “de-storage of a quantity of energy w6 from the storage means 9 and transmission of this energy to the electric motor 8 for the application of supplementary power to the HP shaft” [0044]).
Claims 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi and further in view of Mathie (US 20170324100).
Regarding Claim 11, Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi teaches the invention as discussed for claim 8. Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi is silent about:
further comprising a recirculation flow, the recirculation flow configured to divert at least a portion of at least one of the first bleed flow or the second bleed flow downstream of the secondary compressor outlet to upstream of the secondary compressor inlet.
However, Mathie teaches:
a recirculation flow (Mathie Fig 3A-C, 108), the recirculation flow configured to divert at least a portion of at least one of the first bleed flow or the second bleed flow downstream of the secondary compressor outlet (Fig 3C, 128) to upstream of the compressor inlet (Fig 3A-C, 108).
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi with Mathie’s structure as discussed above, in order to enable “the valve 106 operating in the second mode of operation can provide cathode-blocking functionality. This mode of operation can be commanded to occur when the fuel cell stack is not operating” as taught by Mathie [0028].
Regarding Claim 12, Robic in view of Hannwacker, West, Rainville, Butler, Mackin, Azizi and Mathie teaches the invention as discussed for claim 11. Robic in view of Hannwacker, West, Rainville, Butler, Mackin, Azizi and Mathie, as discussed so far, is silent about:
comprising a recirculation control device, the recirculation control device configured to control a proportion of the recirculation flow diverted to upstream of the secondary compressor inlet.
However, Mathie teaches:
a recirculation control device (Mathie Fig 3A-C, 106), the recirculation control device configured to control a proportion of the recirculation flow diverted to upstream of the compressor inlet (via 108 in Fig 3B).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Robic in view of Hannwacker, West, Rainville, Butler, Mackin, Azizi and Mathie and further in view of Taylor (US 20170363014).
Regarding Claim 13, Robic in view of Hannwacker, West, Rainville, Butler, Mackin, Azizi and Mathie teaches the invention as discussed for claim 12.
Robic in view of Hannwacker, West, Rainville, Butler, Mackin, Azizi and Mathie is silent about:
further comprising a mixing assembly, the mixing assembly configured to entrain at least one of the first bleed flow or the second bleed flow upstream of the secondary compressor inlet with at least a portion of the recirculation flow.
However, Taylor teaches:
A mixing assembly (Image A, from Taylor’s Fig 2, below: region around the diamond shape element, marked with a box) at least one of the first bleed flow or the second bleed flow (flow from 66) upstream of a secondary compressor inlet (inlet of 72) with at least a portion of a recirculation flow (indicated by dotted arrows in the image below; flow from 76 through 80, 88 (bottom of the image), 78, 68, 88 (top of the image)).
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Robic in view of Hannwacker, West, Rainville, Butler, Mackin, Azizi and Mathie with Taylor’s structure as discussed above, because “Recirculation of a portion of the output airflow enables the compressor 72 to operate within a stable operating flow rate and/or speed even if such operation results in excess airflow and pressure beyond that demanded” as taught by Taylor [0047].
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Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi and further in view of Christopherson (US 20180009536).
Regarding claim 14, Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi teaches the invention as discussed for claim 8.
Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi, teaches the secondary compressor, but Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi, as discussed so far, is silent about:
a mixing assembly, the mixing assembly configured to:
receive the first bleed flow at a first pressure;
receive the second bleed flow at a second pressure, wherein the second pressure is greater than the first pressure;
entrain the first bleed flow with the second bleed flow; and
communicate a combined bleed flow from the secondary compressor outlet, the combined bleed flow having a third pressure, wherein the third pressure is greater than the first pressure and less than the second pressure.
However, Christopherson teaches a gas turbine with a bleed flow extraction system (title), and:
a mixing assembly (Christopherson Fig 2, the group formed by 140, and related elements 132, 152, 154, 124, 150, 104 and 130), the mixing assembly configured to:
receive the first bleed flow at a first pressure (110 flowing through 152 and 154);
receive the second bleed flow at a second pressure (120 flowing through 124), wherein the second pressure is greater than the first pressure (110 is low pressure bleed air and 120 is high pressure bleed air);
entrain the first bleed flow with the second bleed flow (“The resulting streams of bleed air…may be merged” Abstract); and
communicate a combined bleed flow from a secondary compressor (102) outlet (flow leaving 102 and flowing through 132), the combined bleed flow having a third pressure (pressure inside 132), wherein the third pressure is greater than the first pressure (discharge of 102 is higher than 110; “compressor 102 to increase the low pressure bleed air 110 pressure” [0039]) and less than the second pressure (“High pressure bleed air 120 is passed through turbine 104, where it expands as it rotates turbine 104. Rotating turbine 104 drives compressor 102” [0027]; and “A check valve in the compressor outlet line 132 may be used to prevent high pressure air from back pressuring the low pressure compressor” [0031], and “One skilled in the art will appreciate that regulating valve 150 and bypass valve 154 need not be operated in only the open or closed positions. In addition, regulating valve 150 and bypass valve 154 may operate independently from each other to achieve the desired flow rates and pressures through air cycle machine 100. Indeed, according to an alternative embodiment regulating valve 150 may be used simultaneously with bypass valve 154, to adjust the overall ratio of bleed air providing from bleed ports 112, 122 as well as the amount of bleed air that is expanded and compressed using air cycle machine 100” [0034] and “It should be appreciated that although two regulating valves are discussed above, air cycle machine 100 may include any number and variety of flow regulating devices to achieve the desired pressure and temperature of bleed air entering junction 140” [0035]).
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to provide Robic in view of Hannwacker, West, Rainville, Butler, Mackin and Azizi with Christopherson’s structure as discussed above, in order “to achieve the desired flow rates and pressures” as taught by Christopherson [0034] before supplying it to a fuel cell.
Claims 15 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Robic (US 2017/0226934 A1) in view Hannwacker (US 20170248315), Rainville (US 2005/0095474 Al), West (EP 967676), Butler (US 2023/0120297), and Mackin (20130187007)
Regarding claim 15, Robic teaches:
A method of operating an anti-stall system for an aircraft ([0001]), the aircraft comprising a propulsion system (aircraft engines [0001]) including, in serial flow relationship, a low-pressure compressor (1, Figs. 1-5), a high-pressure compressor (2, Fig. 1-5), and a combustor (3, Fig. 2), and a fuel cell assembly (fuel cell [0034], and Fig 2, element 9 SOFC),
detecting, with at least one sensor (“current surge that can be detected and the value of the signal” [0072] – the teaching of a sensor is implicit since this teaches to detect and produce a signal), an operating parameter indicative of a compressor stall condition (referring to Fig. 6 “This diagram conventionally gives the change in the compression ratio delivered by the compressor as a function of the flow rate passing through it and is parameterised according to its rotation speed, which is expressed as a percentage of the rotation speed at take-off. According to the operating parameters of the engine, the point representing the operation of the compressor moves in this diagram while remaining below the surge line A, which for its part is a characteristic of the compressor” [0046] – the surge line A represents the compressor stall, and the compressor rotational speed is the operating parameter indicative of a compressor stall); and executing, with at least one controller (FADEC [0072]), an anti-stall action (adjust the balances between gas generator and the electric motor) responsive to the operating parameter having achieved a compressor stall condition threshold (“a current surge that can be detected and the value of the signal of which with respect to defined thresholds can serve to adjust the balances between the gas generator and the electric motor by varying the control laws of the FADEC system” [0072]), wherein receiving the data indicative of the compressor stall condition (“a current surge that can be detected and the value of the signal of which with respect to defined thresholds” [0072]) comprises receiving data indicative of rotational speed (rotational speed, as discussed above) of at least one shaft of the propulsion system (shaft connected to the compressor, as discussed above), and receiving sensor data of a change in rotational speed of the at least one shaft of the propulsion system (the data from the sensors was already discussed above; the change in speed is taught by “it allows electrical coupling of the two shafts in descent (taking from the LP shaft and adding to the HP shaft in order to avoid chamber extinctions),it allows coupling of the two shafts for better control of the acceleration of the two bodies and better management of their rotation speeds” [0070] and “a current surge that can be detected and the value of the signal of which with respect to defined thresholds can serve to adjust the balances between the gas generator and the electric motor by varying the control laws of the FADEC system” [0072]),
Robic teaches a combustor but is silent about:
the combustor including an inner liner and an outer liner defining a combustion chamber therebetween.
However, Hannwacker teaches a combustor assembly (title) for a turbofan engine (Fig. 1), and:
the combustor including an inner liner (Hannwacker 114, Fig 2 [0027]) and an outer liner (Hannwacker 116, Fig 2 [0027]) defining a combustion chamber therebetween (108, Fig 2),
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Robic with a combustor with an inner liner and an outer liner in order to facilitate “a combustor assembly capable of effectively joining multiple components formed of CMC materials” As taught by Hannwacker [0005].
Robic in view of Hannwacker is silent regarding the method comprising:
wherein the anti-stall action comprises increasing or decreasing at least one fuel cell parameter, wherein the fuel cell assembly is integrated with the inner liner or the outer liner and is in fluid communication with the combustion chamber
However, Rainville teaches compressor sure detection system (Title) and:
wherein the anti-stall action comprises increasing or decreasing at least one fuel cell parameter (“The controller controls a motor driving a compressor and a back pressure valve at the cathode exhaust of the fuel cell module to control the pressure in the fuel cell module to remove the surge condition.” Abstract),
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 Robic in view of Hannwacker to incorporate Rainville’s teachings as discussed above in order to measure “the airflow through the compressor, and provides an indication of a reverse airflow through the compressor for surge protection” as taught by Rainville (Rainville, Abstract).
Robic in view of Hannwacker and Rainville is silent about:
wherein the fuel cell assembly is integrated with the inner liner or the outer liner and is in fluid communication with the combustion chamber.
However, West teaches a jet engine (title), and:
wherein the fuel cell assembly (33, Fig 2, [0009]) is integrated with the inner liner or the outer liner and is in fluid communication with the combustion chamber (“A number of fuel cell tiles 33 are arranged in the wall 322 of the combustion chamber” [0009]);
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Robic in view of Hannwacker and Rainville with fuel cells in the liner of the combustor as taught by West because “this completely eliminates moving parts from the electricity generation process and allows the components associated with electricity generation to be disposed within the housing of the engine” [0008].
Robic in view of Hannwacker, West and Rainville teaches the low-pressure compressor, the high-pressure compressor, but is silent about:
the propulsion system further comprising a secondary compressor
wherein the second compressor is in airflow communication with the fuel cell assembly
However, Butler teaches an aircraft propulsion system, with a low-pressure compressor (410, Fig 4), a high-pressure compressor (411, Fig. 4)], and:
the propulsion system further comprising a secondary compressor (412,Fig. 4)
wherein the second compressor is in airflow communication with the fuel cell assembly (452, Fig. 4).
It would have been obvious to a person having ordinary skill the art before the effective filing date of the claimed invention to provide Robic in view of Hannwacker, West, and Rainville with Butler's teachings discussed above, in order to “provide air to an input port 455 of the PEM fuel cell system 452” as taught by Butler [0024].
Robic in view of Hannwacker, West, Rainville and Butler teaches the low-pressure compressor, the high-pressure compressor, but is silent about:
wherein the secondary compressor is fluidly coupled to the low-pressure compressor via a first bleed flow path to receive a first bleed flow from the low-pressure compressor, wherein the secondary compressor is fluidly coupled to the high-pressure compressor via a second bleed flow path to receive a second bleed flow from the high-pressure compressor, to provide at least one of the first bleed flow or the second bleed flow to the fuel cell assembly
However, Mackin teaches an aircraft engine (abstract, Fig. 7), comprising a high pressure compressor and a low pressure compressor (212, 210), a secondary compressor (232, Fig. 7, [0065]), and:
wherein the secondary compressor is fluidly coupled to the low-pressure compressor (210) via a first bleed flow path (via, inter alia, 236) to receive a first bleed flow from the low-pressure compressor (from 210 to 232, Fig. 7), wherein the secondary compressor is fluidly coupled to the high-pressure compressor via a second bleed flow path (image below) to receive a second bleed flow from the high-pressure compressor (from 212 to 232), wherein the second compressor is in airflow communication to provide at least one of the first bleed flow or the second bleed flow (Fig. 7).
It would have been obvious to a person having ordinary skills in the art before the effective filing date of the claimed invention to provide Robic in view of Hannwacker, West, Rainville and Butler with Mackin's structure discussed above, such that the secondary compressor is fluidly coupled to the low-pressure compressor via a first bleed flow path to receive a first bleed flow from the low-pressure compressor, wherein the secondary compressor is fluidly coupled to the high-pressure compressor via a second bleed flow path to receive a second bleed flow from the high-pressure compressor, wherein the second compressor is in airflow communication with the fuel cell assembly to provide at least one of the first bleed flow or the second bleed flow to the fuel cell assembly, in order to provide “a dual inlet source to enable the compressor 232 to receive bleed air from a high-pressure source (e.g., the high-pressure compressor 212) during a first period of operation (e.g., when the engine 700 is idle) and enable the compressor 232 to draw bleed air from a low-pressure source during a second period of operation (e.g., during cruising altitudes)” as taught by Mackin [0065].
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Regarding claim 19, Robic in view Hannwacker, Rainville, West, Butler and Mackin teaches the invention as discussed for claim 15. Robic further teaches:
wherein the anti-stall action further comprises increasing or decreasing or decreasing at least one combustion engine parameter (“a current surge that can be detected and the value of the signal of which with respect to defined thresholds can serve to adjust the balances between the gas generator and the electric motor by varying the control laws of the FADEC system This system may comprise a power electronics management part, which addresses the control of the speeds of the electric motor, and a thermal management part, which addresses the control laws of the thermal part of the engine (the gas generator)” [0072], where adjusting the balances involve changing at least one combustion engine (gas generator) parameter)
Claim 16, 17 are rejected under 35 U.S.C. 103 as being unpatentable over Robic in view of Robic in view Hannwacker, Rainville, West, Butler and Mackin further in view of Azizi.
Regarding claim 16, Robic in view Hannwacker, Rainville, Butler and Mackin teaches the invention as discussed for claim 15, but is silent about wherein adjusting the at least one fuel cell parameter comprises controlling at least one of the first bleed flow or the second bleed flow into the fuel cell assembly
However, Azizi teaches an academic research about stall/surge dynamics of a multi-stage air compressor of a hybrid solid oxide fuel cell-gas turbine system (Title), and:
wherein adjusting the at least one fuel cell parameter (Azizi teaches compressor surges can result from lack of shutdown control strategy and further teaches control parameters (pp 409 last paragraph and page 410 first paragraph)): comprises controlling at least one of the first bleed flow or the second bleed flow into the fuel cell assembly (Aziz page 410, 1st column, 1st paragraph “air flow was controlled by manipulating the shaft speed and cell temperature was controlled by adjustment of the air flow setpoint”).
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 Robic in view Hannwacker, Rainville, West, Butler and Mackin to incorporate Azizi’s structure as discussed above in order enable “control strategies […] to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor” as taught by Azizi (Azizi, Abstract) and provide a higher efficiency fuel-cell-gas-turbine hybrid system (Azizi, p.410, “Fig. 1 shows the model of a 4 MW hybrid power generation system that has been previously developed at the National Fuel Cell Research Center (NFCRC) at the University of California, Irvine using MATLAB/Simulink tools. This model was used to show that such systems, when properly designed and controlled, possess higher efficiency than previously tested SOFC-GT systems in power generation applications”).
Regarding claim 17, Robic in view Hannwacker, Rainville, West, Butler and Mackin teaches the invention as discussed for claim 15, but is silent about wherein adjusting the at least one fuel cell parameter comprises controlling a fuel cell fuel supply.
However, Azizi teaches an academic research about stall/surge dynamics of a multi-stage air compressor of a hybrid solid oxide fuel cell-gas turbine system (Title), and:
wherein adjusting the at least one fuel cell parameter (Azizi teaches compressor surges can result from lack of shutdown control strategy and further teaches control parameters (pp 409 last paragraph and page 410 first paragraph)): comprises controlling a fuel cell fuel supply (Aziz p.410, 1st column, 1st paragraph “fuel utilization was controlled by manipulating the fuel flow”).
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 Robic in view Hannwacker, Rainville, West and Butler to incorporate teachings of Azizi in order enable “control strategies […] to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor” as taught by Azizi (Azizi, Abstract) and provide a higher efficiency fuel-cell-gas-turbine hybrid system (Azizi, p.410, “Fig. 1 shows the model of a 4 MW hybrid power generation system that has been previously developed at the National Fuel Cell Research Center (NFCRC) at the University of California, Irvine using MATLAB/Simulink tools. This model was used to show that such systems, when properly designed and controlled, possess higher efficiency than previously tested SOFC-GT systems in power generation applications”).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Robic in view of Robic in view Hannwacker, Rainville, West, Butler and Mackin and further in view of Gallant (US 4083235).
Regarding claim 18, Robic in view Hannwacker, Rainville, West, Butler and Mackin teaches the invention as discussed for claim 15. Robic in view Hannwacker, Rainville, West, Butler and Mackin is silent about:
transmitting a stall condition message to a pilot responsive to the operating parameter having achieved the compressor stall condition threshold.
However, Gallant teaches a compressor stall warning system (Title) and:
transmitting a stall condition message to a pilot (“a signal is furnished to the aircraft pilot warning him of impending aircraft engine stall” (Abstract)) responsive to the operating parameter having achieved a compressor stall condition threshold (“when the ratio TIT/N exceeds 16 degree C per radian per second the signaling device should be activated, providing a warning to the pilot of impending stall within 1-4 seconds” (Col 3 ln 28-31).
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 Robic in view Hannwacker, Rainville, West, Butler and Mackin to incorporate the teachings of Gallant as discussed above in order to enable the pilot to avoid “conditions [that] describe "compressor stall" and [that] can lead to turbine wheel failure if the compressor stall is not recognized and corrective action not taken” (Gallant Col 1 ln 17-19).
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Robic in view of Robic in view Hannwacker, Rainville, West, Butler and Mackin and further in view of Kumar (US 20170227013).
Regarding claim 20, Robic in view Hannwacker, Rainville, West, Butler and Mackin teaches the invention as discussed for claim 15. Robic in view Hannwacker, Rainville, West, Butler and Mackin as discussed so far, is silent about:
ceasing execution, of the anti-stall action if the operating parameter falls below the compressor stall condition threshold.
However, Kumar teaches a method for addressing a compressor stall [0038] and:
ceasing execution, of the anti-stall action if the operating parameter falls below the compressor stall condition threshold (Fig 5 Method 500’s last step is Return; “increase air flow recirculation through the compressor, thus increasing mass air flow through the compressor and lowering the pressure ratio, pushing compressor operation out of surge. Method 500 then returns” [0038]).
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 Robic in view Hannwacker, Rainville, West, Butler and Mackin to incorporate the teachings of Kumar in order to improve the efficiency of the compressor by resetting the system once the stall condition is cleared, in a similar manner as taught by Kumar: “the compressor variable ported shroud may open to maximize the surge margin if the engine is operating in a condition where surge margin is low. The port may be closed to improve the efficiency of the compressor, resulting in better fuel economy” (Kumar, [0039]).
Response to Arguments/Remarks
Applicant’s arguments have been carefully considered but they are not persuasive. However, to the extent possible they were addressed in the body of the rejections at the relevant locations.
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.
Correspondence
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/ROBERTO TOSHIHARU IGUE/ Examiner, Art Unit 3741 /PHUTTHIWAT WONGWIAN/Supervisory Patent Examiner, Art Unit 3741