MITSUBISHI HITACHI POWER SYSTEMS, LTD.

Patent Trials and Appeals Board

Feb 28, 2022

2021002519 (P.T.A.B. Feb. 28, 2022)

UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 15/108,420 06/27/2016 Keisuke YAMAMOTO 2016-0852A 7520 513 7590 02/28/2022 WENDEROTH, LIND & PONACK, L.L.P. 1025 Connecticut Avenue, NW Suite 500 Washington, DC 20036 EXAMINER GOYAL, ARUN ART UNIT PAPER NUMBER 3741 NOTIFICATION DATE DELIVERY MODE 02/28/2022 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): eoa@wenderoth.com kmiller@wenderoth.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte KEISUKE YAMAMOTO, TAKASHI SONODA, AKIHIKO SAITO, FUMINORI FUJII, HISASHI NAKAHARA, RYOICHI HAGA, RYUJI TAKENAKA, YOSHIFUMI IWASAKI, WATARU AKIZUKI, ISAMU MATSUMI, NAOHIRO SUMIMURA, and SHINICHI YOSHIOKA Appeal 2021-002519 Application 15/108,420 Technology Center 3700 Before DANIEL S. SONG, BRETT C. MARTIN, and LISA M. GUIJT, Administrative Patent Judges. GUIJT, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision to reject claims 1, 2, and 6-9. We have jurisdiction under 35 U.S.C. § 6(b). 1 We use the word “Appellant” to refer to “applicant” as defined in 37 C.F.R. § 1.42(a). Appellant identifies the real party in interest as Mitsubishi Hitachi Power Systems, LTD. Appeal Br. 2. Appeal 2021-002519 Application 15/108,420 2 We AFFIRM. THE CLAIMED SUBJECT MATTER Appellant’s invention relates to “a fuel control device, a combustor, a gas turbine, a control method, and a program.” Spec. [0001].2 Claims 1, 8, and 9 are the independent claims on appeal. Claim 1, reproduced below, is illustrative of the claimed subject matter, with disputed claim limitations italicized for emphasis. 1. A fuel control device, comprising: a combustion temperature estimation value calculation unit that proactively calculates a temperature estimation value according to a load change when a mixture of fuel and inflow air is burned using an atmospheric condition, an opening degree command value of a valve that controls the amount of air that is mixed with the fuel and burned, and an output prediction value calculated on the basis of a fuel control signal command value used for calculation of a total fuel flow rate flowing through a plurality of fuel supply systems; a fuel distribution command value calculation unit that calculates a fuel distribution command value indicating a distribution of fuel output from the plurality of fuel supply systems on the basis of the temperature estimation value, and outputs the fuel distribution command value; and a valve opening degree calculation unit that calculates each valve opening degree of a fuel flow rate control valve of the plurality of fuel supply systems on the basis of the fuel distribution command value and the total fuel flow rate based on the fuel control signal command value, 2 We refer to the bracketed numbering in the Appellant’s Specification as paragraphs, although we note that the numbers often correspond to multiple paragraphs. Appeal 2021-002519 Application 15/108,420 3 wherein a time delay of the temperature estimation value is compensated by proactively calculating the temperature estimation value. THE REJECTIONS The rejections before us on appeal are: I. Claims 1, 2, and 6-9 stand rejected under 35 U.S.C. § 112(a) for failing to comply with the written description requirement. II. Claims 1, 2, and 6-9 stand rejected under 35 U.S.C. § 112(b) for failing to comply with the definiteness requirement. III. Claims 1, 2, and 6-9 stand rejected under 35 U.S.C. § 102(a)(1) as anticipated by Atsushi (JPH0610711A; published Jan. 18, 1994).3 OPINION Rejection I Regarding independent claim 1, the Examiner finds that the claim limitation, “wherein a time delay of the temperature estimation value is compensated by proactively calculating the temperature estimation value,”4 lacks written description support in Appellant’s Specification. Final Act. 2. To satisfy the written description requirement, the Specification must describe the claimed invention in sufficient detail that one skilled in the art 3 We rely on the English language translation, PCT/JP2015/054097, as provided in the record. 4 Appellant amended the claims to include this limitation on July 31, 2019, citing the Specification [0024] as written description support. Amend. 5. Appeal 2021-002519 Application 15/108,420 4 can reasonably conclude that the inventor had possession of the claimed subject matter as of the filing date. Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555, 1562-63 (Fed. Cir. 1991). The written description requirement is met when the disclosure “allow[s] one skilled in the art to visualize or recognize the identity of the subject matter purportedly described.” Enzo Biochem, Inc. v. Gen-Probe Inc., 323 F.3d 956, 968 (Fed. Cir. 2002). In particular, the Examiner finds that “Paragraph [0024] of the Specification “discloses ‘it is possible to proactively compensate for a time delay of the turbine inlet temperature estimation value caused by feedback of an actual gas turbine output value,’ . . . and not ‘compensated by proactively calculating the temperature estimation value’ as claimed.” Final Act. 2-3. In other words, the Examiner finds that the Specification “disclose[s] how to calculate ‘a turbine inlet value,’” but not the limitation as claimed. Id. In this regard, the Examiner appears to emphasize that the claimed “temperature estimation value” has antecedent basis in the claim limitation “a combustion temperature estimation value calculation unit that proactively calculates a temperature estimation value,” whereas the Specification’s description of a time delay relates to a turbine inlet temperature estimation value. We agree with the Examiner’s claim construction relative to independent claim 1, in that the recitation of “a combustion temperature estimation value calculation unit that proactively calculates a temperature estimation value” implies that the claimed “temperature estimation value” is a combustion temperature estimation value. We consider the Specification to determine whether there is written description support for the proactive compensation of a time delay of the combustion temperature estimation Appeal 2021-002519 Application 15/108,420 5 value (as claimed), as compared to a proactive compensation of a time delay of an estimated value of the temperature of the combustion gases at the turbine inlet (as the Examiner alleges is the more limited disclosure in the Specification)-and also whether this is the same value. The Specification describes the combustor separately from the turbine, and combustion within the combustor separately from the temperature of combustion gas at the inlet of the turbine. See, e.g., Spec. [0001], Figure 1. In particular, the Specification discloses, with reference to Figure 1, that “gas turbine 10 includes . . . a combustor 12 that mixes the compressed air with a fuel gas, burns the gas, and generates a combustion gas at a high temperature” and also “turbine 13 that is driven by the combustion gas.” Id. at [0018]. With reference to Figure 14, the Specification discloses that the prior art fuel control device estimates a temperature of combustion gas “at an inlet of the turbine on the basis of an atmospheric pressure, an atmospheric temperature, and inlet guide vane (IGV) opening degree designation value, and a gas turbine output value.” Id. at [0002]; cf. id. at [0036] (similarly disclosing that, according to a fifth embodiment of the present invention, “turbine inlet temperature estimation unit 52 calculates a turbine inlet temperature on the basis of the gas turbine output prediction value . . . , an atmospheric temperature, an atmosphere pressure, and an IGV opening command” (emphasis added)). Critically, the Specification also discloses “a first aspect of the present invention, a fuel control device includes a combustion temperature estimation value calculation unit that calculates a [combustion] temperature estimation value when a mixture of fuel and Appeal 2021-002519 Application 15/108,420 6 inflow air is burned using an atmospheric condition.” Id. at [0007]; see also id. at [0014], [0015]. Thus, we agree with the Examiner that the Specification distinguishes between a (estimated) combustion temperature value, which may be the high temperature of the combustion gas within the combustor, and also a (estimated) temperature of the combustion gas at the inlet of the turbine. See also id. at [0020], [0023] (describing “turbine inlet temperature estimation unit 52 [that] estimates a temperature of the combustion gas at the inlet of the turbine”); cf. (claim 1, reciting “a combustion temperature estimation value calculation unit”). Regarding a time delay, Paragraph [0024] of the Specification states: In the method of the related art, the turbine inlet temperature estimation value is determined according to an actual output of the gas turbine. In this case, the fuel control device of the related art determines a distribution ratio of fuel to actually perform control of the supply of the fuel to each system. As a result, a delay is caused due to various factors until the output of the gas turbine becomes a desired value. The various factors include, for example, a mechanical delay (a valve operation delay, a pressure response delay, or a combustion delay) or a control delay such as time consumed for, for example, filter processing for removing noise from a signal. According to the method of the related art, when the fluctuation of the load is large, the fuel distribution ratio is determined on the basis of the turbine inlet estimation value according to the actual output of the gas turbine. Accordingly, the output value of the gas turbine has already changed when the valve opening degree is actually controlled on the basis of the determined distribution ratio, and the control using the previously calculated valve opening degree may not fit the actual situation. However, according to this embodiment, by calculating the turbine inlet temperature estimation value using a prediction Appeal 2021-002519 Application 15/108,420 7 value of the gas turbine output on the basis of the [fuel control signal command value or] CSO, it is possible to proactively compensate for a time delay of the turbine inlet temperature estimation value caused by feedback of an actual gas turbine output value, which may occur in the method of the related art, to calculate the turbine inlet temperature value. See also id. at [0003] (disclosing, inter alia, with reference to Figure 15, “a turbine inlet temperature during a load change”); [0005] (disclosing that “[w]hen an output of a gas turbine fluctuates, an inlet temperature of the turbine correspondingly changes,” wherein “if the fluctuation is sharp, a turbine inlet temperature estimation value calculated [according to an actual output of the gas turbine] is not in time for a change in an actual gas turbine inlet temperature.”). Further, the Specification discloses that the invented fuel control device “suppress[e]s a deviation between a target fuel system fuel ratio for the turbine inlet temperature and an actual fuel system fuel ratio even in a transient period of load change.” Id. at [0016] (emphasis added). Thus, we also agree with the Examiner that the time delay described in the Specification is only expressly disclosed relative to a turbine inlet temperature estimation value and not a combustion temperature estimation value. Finally, the Specification discloses that “turbine inlet temperature estimation unit 52 is an example of a combustion temperature estimation value calculation unit.” Spec. [0038]. However, we find this disclosure insufficient to provide written support for the subject matter of claim 1, which more broadly recites that a time delay of a combustion temperature estimation value is proactively compensated. In other words, but for the time delay relative to a turbine inlet temperature estimation value, no other Appeal 2021-002519 Application 15/108,420 8 time delays relative to a combustion temperature estimation value are disclosed in the Specification. Appellant does not address the discrepancy between a combustion temperature estimation value, as claimed, and a time delay of a turbine inlet temperature estimation value, as disclosed in the Specification. Appellant argues that “by the present invention, the turbine inlet temperature estimation value is calculated by using a prediction value of the gas turbine output on the basis of the CSO,” and “[t]herefore, ‘it is possible to proactively compensate for a time delay of the turbine inlet temperature estimation value.’” Appeal Br. 5 (citing Spec. [0024] for discussing the problem in the prior art). Appellant’s argument, however, does not address the Examiner’s rejection, which emphasizes the difference between the time delay described in the Specification in the prior art relative to only a turbine inlet temperature estimation value, and the claimed time delay relative to- more broadly-a combustion temperature estimation value calculation unit, which may be based on the high temperature of the combustion gas within the combustor, as discussed supra. To the extent the Examiner determines that Appellant’s Specification does not sufficiently disclose how to proactively calculate a temperature estimation value, the Examiner may consider entering a rejection under 35 U.S.C. § 112(a) as failing to comply with the enablement requirement. Independent claims 8 and 9 recite, “proactively calculating a temperature estimation value . . . when a mixture of fuel and inflow air is burned using an atmospheric condition,” which implies, according to the Specification supra, that the claimed temperature estimation value is a combustion temperature estimation value, and not a turbine inlet Appeal 2021-002519 Application 15/108,420 9 temperature estimation value, which is described in the Specification relative to a time delay. Appeal Br. 12-13 (Claims App.). Claims 8 and 9 further recite the same limitation disputed relative to independent claim 1 supra: “wherein a time delay of the temperature estimation value is compensated by proactively calculating the temperature estimation value.” Id. Thus, we apply the same analysis as set forth supra to independent claims 8 and 9, and find insufficient written description support for the broader context of a time delay of a temperature estimation value based on burning a mixture of fuel and inflow air (i.e., combustion). Accordingly, we sustain the Examiner’s rejection of independent claims 1, 8, and 9, and claims 2, 6, and 7 depending therefrom, under 35 U.S.C. § 112(a) as failing to comply with the written description requirement. Rejection II Regarding independent claims 1, 8, and 9, the Examiner finds that the claim limitation “wherein a time delay of the temperature estimation value is compensated by proactively calculating the temperature estimation value” is indefinite, because “[i]t is not clear how a time delay in one value is compensated by proactively calculating the same value.” Final Act. 3; Ans. 4. Appellant argues that the claims do not require the two recitations of “the temperature estimation value” to have the same numeric value, or more accurately, to be calculated in a single way. Appeal Br. 6-7 (citing Spec., pp. 14-15 (“[0024]”), pp. 10-11 (“[00200]”). Appellant asserts that “what is being compensated for is “a time delay of the temperature estimation value . Appeal 2021-002519 Application 15/108,420 10 . . by proactively calculating the temperature estimation value.” Reply Br. 3. A claim is properly rejected as indefinite under 35 U.S.C. § 112(b) if, after applying the broadest reasonable interpretation in light of the specification, the metes and bounds of a claim are not clear because the claim “contains words or phrases whose meaning is unclear.” In re Packard, 751 F.3d 1307, 1310, 1314 (Fed. Cir. 2014) (per curiam). The test for definiteness under 35 U.S.C. § 112(b), is whether “those skilled in the art would understand what is claimed when the claim is read in light of the specification.” Orthokinetics, Inc. v. Safety Travel Chairs, Inc., 806 F.2d 1565, 1576 (Fed. Cir. 1986) (citations omitted). As described in the Specification and discussed supra, we find that the meaning of the disputed limitation is clear, in that “a time delay of the temperature estimated value” means, for example, a time delay caused by taking an actual measurement that results in inaccurate fuel control relative to an actual gas turbine output, and the claim language “is compensated by proactively calculating the temperature estimated value” means counteracting such inaccuracy caused by a time delay by proactively calculating the temperature estimated value, for example, by using a predicted value. See, e.g., Spec. [0024] (“by calculating the turbine inlet temperature estimation value using a prediction value of the gas turbine output on the basis of the CSO, it is possible to proactively compensate for a time delay of the turbine inlet temperature estimation value caused by feedback of an actual gas turbine output value”). Accordingly, we do not sustain the Examiner’s rejection of independent claims 1, 8, and 9, and claims 2, 6, and 7 depending therefrom, Appeal 2021-002519 Application 15/108,420 11 under 35 U.S.C. § 112(b) as failing to comply with the definiteness requirement. Rejection III To anticipate a claim, a prior art reference must disclose every limitation of the claimed invention, either expressly or inherently. Blue Calypso, LLC v. Groupon, Inc., 815 F.3d 1331, 1341 (Fed. Cir. 2016). Regarding independent claim 1, the Examiner finds that Atsushi discloses, inter alia, a combustion temperature estimation value calculation unit that proactively calculates a temperature estimation value according to, inter alia, an output prediction value (“turbine load”) calculated on the basis of a fuel control signal command value used for calculation of a total fuel flow rate flowing through a plurality of fuel supply systems. Final Act. 4 (citing Atsushi ¶¶ 4, 17). Appellant argues that Atsushi fails to disclose proactively calculating a temperature estimation value according to an output prediction value calculated on the basis of a fuel control signal command value (CSO) used for calculation of a total fuel flow rate flowing through a plurality of fuel supply systems, as claimed. In support, Appellant submits that Atsushi teaches that a temperature estimation value (i.e., combustor outlet temperature T) is calculated with the actually-measured values (e.g., compressor inlet temperature, compressor outlet pressure, turbine exhaust temperature, turbine load, and combustor air supply amount), which are easy to measure and solves the problem that it is difficult to directly measure the combustion temperature of the combustor. Id. at 9 (citing Atsushi ¶ 24). Appeal 2021-002519 Application 15/108,420 12 We are persuaded by Appellant’s argument. We construe claim 1 to require that a calculation unit proactively estimates a combustion temperature value according to, inter alia, a gas turbine output prediction value5 calculated on the basis of a CSO. Atsushi discloses that a combustor outlet temperature is obtained from a compressor inlet temperature, a compressor outlet pressure, a turbine exhaust temperature, a turbine load (fuel control valve opening) and a combustor air supply amount (compressor inlet guide vane driving device displacement) representing the operating state of the gas turbine, and a pre-mixed fuel supply ratio of a two-stage combustion system properly set to the combustor outlet temperature is calculated in advance. Atsushi ¶ 17. Here, only the pre-mixed fuel supply ratio is disclosed as being set in advance (i.e., proactively), but the pre-mixed fuel supply ratio is not a combustion temperature estimation value, which claim 1, as we interpret it, requires to be proactively calculated. Rather, Atsushi discloses that its combustion temperature value (i.e. combustor outlet temperature) is obtained from real-time measurements of certain variables of the gas turbine. As argued by Appellant, Atsushi also discloses that since the combustion temperature of the outlet of the combustor 2 is very high, it is difficult to directly detect the combustion temperature. However, if the characteristic of the compressor and the turbine are known in advance, the combustor outlet 5 The Specification explains that the output prediction value is an output prediction value of the gas turbine, which is calculated, for example, by using a table or a function that associates a gas turbine output prediction value with a fuel control signal command value or CSO, or alternatively, by performing an interpolation calculation, wherein “[a] correspondence between the CSO and the gas turbine output prediction value is determined by performing, for example, a simulation or an experiment in advance.” Spec. [0019]. Appeal 2021-002519 Application 15/108,420 13 temperature T can be determined from the parameters of the compressor inlet temperature, the compressor outlet pressure, the turbine exhaust temperature, the turbine load (fuel flow rate or fuel control valve opening), and the combustor air supply amount (air compressor inlet guide vane angle). Therefore, a combustor outlet temperature T can be calculated in a computer 16 from the temperature detectors 31, 34, a pressure detector 33, an IGV actual displacement signal, and a control valve 35 actual operating signal corresponding to the parameters, and input to an arithmetic section 36. Id. at ¶ 24. Although Atsushi uses the language “in advance,” we find that a preponderance of the evidence fails to support the Examiner’s finding that Atsushi discloses using a gas turbine output prediction value calculated on the basis of a fuel control signal command value (or CSO), but rather, Atsushi teaches that the gas turbine load or fuel flow rate or fuel control valve opening is based on an actual, or real-time, operating signal. Accordingly, we do not sustain the Examiner’s rejection of independent claim 1, and claims 2, 6, and 7 depending therefrom. The Examiner relies on the same deficient finding relative to Atsushi for disclosing a similar claim limitation as recited in independent claims 8 and 9, and therefore, for essentially the same reasons as stated supra, we do not sustain the Examiner’s rejection of independent claims 8 and 9. CONCLUSION The Examiner’s rejection of claims 1, 2, and 6-9 under 35 U.S.C. § 112(a) is affirmed, and the Examiner’s rejections of claims 1, 2, and 6-9 under 35 U.S.C. §§ 112(b) and 102(a)(1) are reversed. Appeal 2021-002519 Application 15/108,420 14 DECISION SUMMARY In summary: Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1, 2, 6-9 112(a) Written description 1, 2, 6-9 1, 2, 6-9 112(b) Indefiniteness 1, 2, 6-9 1, 2, 6-9 102(a)(1) Atsushi 1, 2, 6-9 Overall Outcome 1, 2, 6-9 TIME PERIOD FOR RESPONSE No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R. § 1.136(a)(1)(iv). AFFIRMED