Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 1/8/26 has been entered.
Response to Arguments
The following is in response to the applicant’s remarks filed 1/8/26.
The applicant submits that the cited references do not teach the newly amended limitations of claim 1. Specifically, the applicant submits that neither Kasahara nor Chen teach any flow stream comprising nitrogen or water or the claimed formula for excess fuel ratio.
The examiner respectfully disagrees. Both Kasahara [0083] and Chen [0002] teach that the cathode oxidant gas source is optionally ambient air which is the same as the instant application [0044]. Ambient air is the source of the nitrogen present in both the cited art and the instant application. Additionally, the ambient air supplied to the cathode of Kasahara optionally contains water (non-dry air)[0083], and the fuel cell reaction of both Chen [0016] and Kasahara [0006] generates water. Then, the streams of Kasahara and Chen teach the newly amended limitations regarding the presence of hydrogen, water, and nitrogen in the streams.
Regarding the claimed formula for excess fuel ratio, the examiner maintains that the formula is inherently present in the teaching of the fuel excess ratio in Chen (previously in dependent claim 21). Listing the mathematical formula which is used to calculate the excess fuel ratio does not provide a patentable distinction over the prior art which teaches an excess fuel ratio.
Therefore, the rejection is maintained.
Separately, the applicant submits that the cited art does not teach all the limitations of claim 3. Specifically, the applicant submits that Wang (relied upon for teaching claim 3) does not teach “to minimize parasitic load”.
The examiner respectfully disagrees. Wang teaches wherein the controller (4) determines when to operate the blower or determines the blower speed depending on the excess fuel ratio of the fuel cell stack system (operate based on fuel utilization rate)[0053]. It is true that Wang does not mention parasitic load. However, similar to the above arguments regarding the claimed formula for fuel cell excess ratio, “The inherent teaching of a prior art reference, a question of fact, arises both in the context of anticipation and obviousness.” In re Napier, 55 F.3d 610, 613, 34 USPQ2d 1782, 1784 (Fed. Cir. 1995) (affirmed a 35 U.S.C. 103 rejection based in part on inherent disclosure in one of the references). See also In re Grasselli, 713 F.2d 731, 739, 218 USPQ 769, 775 (Fed. Cir. 1983). It is known in the art, as evidenced in Postlethwaite, US20230006226A1 [0006], that fuel cell components responsible for supplying fuel cell inlets and outlets (pumps/blowers) are responsible for the largest instances of parasitic load in a fuel cell system. Then, the efficient operation of the blower, as taught in Wang, with regard to the fuel utilization efficiency inherently also reduces the impact of the parasitic load of the blower.
Therefore, the rejection is maintained.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1 – 2, 4 – 8, 12, 19, and 21 – 22 are rejected under 35 U.S.C. 103 by Kasahara, US20220293974A1, and Chen, US20160344048A1.
Regarding claim 1, Kasahara teaches a fuel cell stack system [0001] comprising:
a first flow stream comprising hydrogen (fuel stream from tank hydrogen tank (21)) and a second flow stream (recycle fuel stream (12)) comprising hydrogen and nitrogen or water (unused hydrogen fuel and water)[0076], the first and second flow streams mixing to form a third flow stream (recycle fuel (12) combined with fuel supply path (11)[0119][fig. 1],
the third flow stream flowing through an anode inlet in a fuel cell stack in the fuel cell stack system (fuel supply for anode of FC (10))[fig.1], and
a controller (controller (50))[fig. 1][0080],
wherein the controller compares a fuel feed rate (controller operates first, second, and recirculation flow (12) to prevent fuel gas deficiency)[0070]
wherein x_H2O_RC is a mass fraction of water in the second flow stream, x_N2_RC is a mass fraction of nitrogen in the second flow stream, mRc is a mass flow rate of the second flow stream, and m_H2_P is the mass flow rate of fuel in the first flow stream (recirculated outlet flow stream from ejector (26) contains H2O and N2 which must be considered when determining quantity of unused fuel in outlet stream)[0082].
Kasahara does not teach a controller configured to compares an excess fuel ratio of the fuel cell stack system to a target excess fuel ratio of the fuel cell stack system, wherein the excess fuel ratio is defined as the ratio of anode inlet stream flow rate to the fuel consumed ion the fuel cell stack system.
Chen teaches a fuel cell system [0001] comprising an anode inlet flow stream [0042][fig. 1] and a controller (4)[0014] wherein the controller (controller monitors process parameters and sends correction signals based on target values)[0021] is configured to compare an excess fuel ratio (fuel excess ratio)[0042] and wherein the excess fuel ratio is defined as the ratio of anode inlet stream flow rate to the fuel consumed ion the fuel cell stack system (fuel excess ratio is the ratio of the fuel supplied versus the fuel consumed)[0017] wherein the excess fuel ratio is equal to [(1-xH2oRc - x_N2_Rc) m_RC + m_H2_p]/[m_h2_p] (inlet fuel versus fuel in the outlet)[0017].
Further, Chen teaches that the controller configured to compare operating parameters such as excess fuel ratio allows for prolonged life and lower cost [0015]. Then, it would have been obvious to combine the controller configured to compare fuel excess ratio as in Chen into the fuel cell system of Kasahara to prolong fuel cell life and reduce cost.
Regarding claim 2, combined Kasahara teaches the system of claim 1.
Further, Kasahara teaches wherein the fuel cell stack system further comprises a blower, an ejector (ejectors (24)(25)(26)), or a by-pass valve (discharge valve (28))[fig. 1]
Regarding claim 4, combined Kasahara teaches the system of claim 2.
Further, Kasahara teaches wherein the controller determines the operation of the by-pass valve (discharge (28))[0077] depending on the excess fuel ratio of the fuel cell stack system (controller operates first, second, and recirculation flow (12) to prevent fuel gas deficiency)[0070].
Regarding claim 5, combined Kasahara teaches the system of claim 2.
Further, Kasahara teaches wherein the fuel cell stack system comprises a first ejector and a second ejector (ejectors (24)(25)(26))[fig. 1], and the controller (50) determines whether to operate the first ejector, the second ejector, or both the first and second ejectors depending on the excess fuel ratio of the fuel cell stack system (controller operates first, second, and recirculation flow (12) to prevent fuel gas deficiency)[0070].
Regarding claim 6, combined Kasahara teaches the system of claim 1.
Further, Kasahara teaches wherein the fuel cell stack system comprises at least one physical or virtual sensor (pressure sensor (29))[fig. 1][0073].
Regarding claim 7, combined Kasahara teaches the system of claim 6.
Further, Kasahara teaches wherein the physical or virtual sensor is a single point pressure sensor or a differential pressure sensor (pressure sensor (29))[fig. 1][0073]
Regarding claim 8, combined Kasahara teaches the system of claim 7.
Further, Kasahara teaches wherein the physical or virtual sensor measures pressure across the fuel cell stack, measure pressure across an ejector, or measure pressure or across a blower in the fuel cell stack system (pressure sensor (29))[fig. 1][0073].
Regarding claim 12, combined Kasahara teaches the system of claim 6.
Further, Kasahara teaches wherein the physical or virtual comprises a temperature sensor (temperature control inherently requiring a temperature sensor)[0153].
Regarding claim 19, combined Kasahara teaches the system of claim 18.
Further, Kasahara teaches wherein if the fuel cell stack system comprises a first ejector and a second ejector (24)(25)(26), and
wherein the controller further determines whether to operate the first ejector, the second ejector, or both the first ejector and the second ejector depending on the excess fuel ratio of the fuel cell stack system (controller operates first, second, and recirculation flow (12) to prevent fuel gas deficiency)[0070].
Regarding claim 21, combined Kasahara the system of claim 1.
Further, Kasahara teaches wherein the target fuel ratio is based on a target water level (controlling excess water in the circulation flow path)[0131].
Regarding claim 22, combined Kasahara the system of claim 1.
Further, Kasahara teaches wherein the second flow stream comprises hydrogen and water (unused hydrogen fuel and water)[0076],
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Kasahara, US20220293974A1 and Chen, US20160344048A1 as applied to claim 1 above, and further in view of Wang, US20170346118A1.
Regarding claim 3, combined Kasahara teaches the system of claim 2.
Kasahara does not teach wherein the controller determines when to operate the blower or determines the blower speed depending on the excess fuel ratio of the fuel cell stack system to minimize parasitic load.
Wang teaches a fuel cell system [0001] comprising a first second and third flow stream (fuel supply, recirculation flow, combined fresh and recirc flows)[fig. 1] and a controller (4) and a blower [0053] wherein the controller (4) determines when to operate the blower or determines the blower speed depending on the excess fuel ratio of the fuel cell stack system (operate based on fuel utilization rate)[0053] to reduce parasitic load (inherently present). Further, blowers are a common component in fuel cell systems for supply reactant gases to the fuel cell. Then, it would have been obvious to combine the blower of Wang into the fuel cell system of Kasahara as a means of supplying fuel flow.
Claims 9 – 11 and 17 – 18 are rejected under 35 U.S.C. 103 as being unpatentable over Kasahara, US20220293974A1 and Chen, US20160344048A1 as applied to claim 1 above, and further in view of Nikiforow. US20220181660A1.
Regarding claim 9, combined Kasahara teaches the system of claim 8,
Further, Kasahara teaches wherein the controller further measures mass flow rate in the first flow stream or the mass flow rate in the second flow stream (controller measure and controls flow rates of streams)[0117][0122][0127]
Kasahara does not teach, and wherein the controller determines an entrainment ratio of the fuel cell stack system based on the measured pressure across the fuel cell stack or the measured pressure across the ejector, and based on the measured mass flow rate in the first flow stream or the measured mass flow rate in the second flow stream.
Nikiforow teaches a fuel cell system [0001] comprising a first, second, and third flow stream [fig. 1] wherein the controller determines an entrainment ratio of the fuel cell stack system based on the measured pressure across the fuel cell stack or the measured pressure across the ejector, and based on the measured mass flow rate in the first flow stream or the measured mass flow rate in the second flow stream (entailment ratio being a resultant property of injector dimensions are flow rates)[0053][0054][0055][fig. 5]. Further, Nikiforow teaches that measuring the entrainment ratio allows for the ability to control for the optimal mixing section diameter at a mixing point of the first and second flow streams. Then, it would have been obvious to one of ordinary skill in the art to combine the teaching for measuring entrainment ratio as shown in Nikiforow into the fuel cell system of Kasahara to improve stream mixing, as taught by Nikiforow.
Regarding claim 10, modified Kasahara teaches the system of claim 9.
Further, Nikiforow teaches wherein if the entrainment ratio of the system is different than a target entrainment ratio, the controller operates the blower, alters the speed of the blower, operates one or more ejectors, or operates the by-pass valve, and wherein if the one or more ejector comprises a first ejector and a second ejector, the controller determines the operation of the first ejector and the second ejector (controlling entrainment ratio by operating fuel cell components)[0008][0009][0010]
Regarding claim 11, modified Kasahara teaches the system of claim 9.
Combined Kasahara does not teach wherein the entrainment ratio has an uncertainty of less than about 12%.
However, Nikiforow teaches a method of measure entrainment ratio [fig. 5] as well as teaching that the value of said measurement is used to optimize system components [0007]. One of ordinary skill in the art would appreciate that accurate measurement (uncertainty approaching 0%) is required for effective optimization as desired by Nikiforow [0007]. Then, it would have been obvious to one of ordinary skill in the art before the filing date to minimize uncertainty to less than 12% in order to achieve the desired optimization of system components.
Regarding claim 17, Kasahara teaches the system of claim 1.
Further, while Kasahara is silent to the particulars of claim 17, Nikiforow teaches wherein the controller uses a model to determine an entrainment ratio of the fuel cell stack system based on operating conditions of the fuel cell stack system (calculating entrainment ratio based on system parameters such as fuel cell current)[fig. 5][0053][0054][00555].
Further, Nikiforow teaches that modeling the entrainment ratio allows for the ability to control for the optimal mixing section diameter at a mixing point of the first and second flow streams.[0008] Then, it would have been obvious to one of ordinary skill in the art prior to the filing date to combine the teaching for controlling fuel cell system components based on the entrainment ratio as shown in Nikiforow into the fuel cell system of Kasahara to improve stream mixing as taught by Nikiforow.
Regarding claim 18, combined Kasahara teaches the system of claim 6,
Further, while Kasahara is silent to the particulars of claim 18, Nikiforow teaches wherein a model is used to determine the entrainment ratio of the fuel cell stack system, and wherein the model is a correlational model or a component based model (entrainment ratio calculated using components measurements)[0054].
Further, Nikiforow teaches that modeling the entrainment ratio allows for the ability to control for the optimal mixing section diameter at a mixing point of the first and second flow streams.[0008] Then, it would have been obvious to one of ordinary skill in the art prior to the filing date to combine the teaching for controlling fuel cell system components based on the entrainment ratio as shown in Nikiforow into the fuel cell system of Kasahara to improve stream mixing as taught by Nikiforow.
Claims 13 - 15 are rejected under 35 U.S.C. 103 as being unpatentable over Kasahara, US20220293974A1 and Chen, US20160344048A1 as applied to claim 12 above, and further in view of Zhu, teaches US20220223893A1
Regarding claim 13, combined Kasahara teaches the system of claim 12.
Kasahara does not teach wherein the temperature sensor measures a temperature difference across a mixing point in the fuel cell stack system.
Zhu teaches a fuel cell (15) system [fig. 1] comprising a first (14) and second stream (19) that combine to form a third stream (10) at a mixing point (8)[fig. 1] wherein the temperature sensor (inherently present) measures a temperature difference across a mixing point in the fuel cell stack system (measuring temperature of mixing point)[0009]. Further, Zhu teaches measuring the temperature at the mixing point allows for greater control over entrainment ratio and improved operation of the injector [0003][0005]. Then, it would have been obvious to one of ordinary skill in the art prior to the filing date to apply the teaching for measuring temperature at the mixing point as in Zhu into the fuel cell system of Kasahara to improve the operation of the injector as taught by Zhu.
Regarding claim 14, modified Kasahara teaches the system of claim 13.
Further, Zhu teaches wherein the controller determines an entrainment ratio of the fuel cell stack system based on the temperature difference across the mixing point by using energy balance in the fuel cell stack system (entrainment ratio impacted by mixing temperature of first and second flow)[0003][0005]
Regarding claim 15, modified Kasahara teaches the system of claim 13.
Further, Zhu teaches wherein the temperature difference across the mixing point is maximized (optimizing heat recovery the second flow which is a recirculation flow)[0006]
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Kasahara, US20220293974A1 and Chen, US20160344048A1 and Zhu, US20220223893A1 as applied to claim 14 above, and further in view of Nikiforow. US20220181660A1.
Regarding claim 16, modified Kasahara teaches the system of claim 14,
Modified Kasahara does not teach wherein if the entrainment ratio of the system is different than a target entrainment ratio, the controller operates the blower, alters the speed of the blower, operates one or more ejectors, or operates the by-pass valve, and wherein if the one or more ejector comprises a first ejector and a second ejector, the controller determines the operation of the first ejector and the second ejector
Further, Nikiforow teaches wherein if the entrainment ratio of the system is different than a target entrainment ratio, the controller operates the blower, alters the speed of the blower, operates one or more ejectors, or operates the by-pass valve, and wherein if the one or more ejector comprises a first ejector and a second ejector, the controller determines the operation of the first ejector and the second ejector (controlling entrainment ratio by operating fuel cell components)[0008][0009][0010]. Further, Nikiforow teaches that measuring the entrainment ratio allows for the ability to control for the optimal mixing section diameter at a mixing point of the first and second flow streams.[0008] Then, it would have been obvious to one of ordinary skill in the art prior to the filing date to combine the teaching for controlling fuel cell system components based on the entrainment ratio as shown in Nikiforow into the fuel cell system of Kasahara to improve stream mixing as taught by Nikiforow.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to PATRICK M GREENE whose telephone number is (571)270-1340. The examiner can normally be reached M-F 8-5.
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/PATRICK MARSHALL GREENE/Examiner, Art Unit 1724
/STEWART A FRASER/Primary Examiner, Art Unit 1724
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