Ex Parte Myers et alDownload PDFPatent Trial and Appeal BoardDec 22, 201613459979 (P.T.A.B. Dec. 22, 2016) Copy Citation 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. 260398-1 (GETH:0605) 1372 EXAMINER FRANCE, MICKEY H ART UNIT PAPER NUMBER 3748 MAIL DATE DELIVERY MODE 13/459,979 04/30/2012 82438 7590 GE Power & Water Fletcher Yoder PC P.O. Box 692289 Houston, TX 77269-2289 12/23/2016 Scott R. Myers 12/23/2016 PAPER 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. PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte SCOTT R. MYERS and DAVID HUBER Appeal 2015-003417 Application 13/459,979 Technology Center 3700 Before JOHN C. KERINS, STEFAN STAICOVICI, and LEE L. STEPINA, Administrative Patent Judges. STEPINA, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Scott R. Myers and David Huber (Appellants) appeal under 35 U.S.C. § 134 from the Examiner’s decision to reject claims 22-42. We have jurisdiction under 35 U.S.C. § 6(b). We REVERSE. Appeal 2015-003417 Application 13/459,979 CLAIMED SUBJECT MATTER The claims are directed to a method of cooling a power converter. Spec. para. 1. Claims 22, 32, and 39 are independent. Claim 22, reproduced below, is illustrative of the claimed subject matter: 22. A method, comprising: condensing a gas into a liquid using a condenser; pumping the liquid from the condenser to a power converter using a pump, wherein the power converter comprises a transistor; cooling the transistor using the liquid; routing the liquid from the power converter to an evaporator without passing through the condenser, evaporating the liquid into the gas using the evaporator; rotating a turbine using the gas from the evaporator; generating electrical power at a first frequency using a generator coupled to the turbine; and converting the electrical power at the first frequency to electrical power at a second frequency using the power convertor. Appeal Br. 13 (Claims App.) (emphasis added). The prior art relied upon by the Examiner in rejecting the claims on REFERENCES appeal is: Brasz Horek Jensen US 2004/0257840 A1 Dec. 23, 2004 US 2008/0115922 A1 May 22, 2008 US 2010/0283262 A1 Nov. 11, 2010 2 Appeal 2015-003417 Application 13/459,979 THE REJECTION Claims 22-42 are rejected under 35 U.S.C. § 103(a) as unpatentable over Brasz, Jensen, and Horek. OPINION Claim 22 recites, in part, “routing the liquid from the power converter to an evaporator without passing through the condenser.” The Examiner finds that Brasz discloses most of the limitations of claim 1, but relies on Jensen for the above limitation, noting that the components 16, 18, 20, 22 of Jensen “provide a more efficient Rankine cycle as a result of utilizing the waste heat of the components.” Final Act. 3 (citing Jensen, paras. 3, 13, 15, 16, 18, 20; Fig. 1.). The Examiner considers that “it would have been obvious to move the power converter (17, Fig. 1) of Brasz to the location of the first machine component (16) of Jensen in the Brasz Rankine cycle,”1 because such a configuration would “cool the power converter and provide a more efficient power generation cycle as a result of capturing the heat dissipated by the power converter.” Id. The Examiner notes that “without passing through the condenser” implies that no vapor is present (see Final Act. 3) and thus, the Examiner concludes that it would have been obvious to further modify Brasz “by maintaining all of the liquid in a liquid state at the power converter, as taught by Horek, in order to improve fluid flow through the Brasz system and, consequently, pumping efficiency.” Id. at 4. 1 We understand that, in view of Jensen’s teachings, the Examiner is proposing to move power converter 17 of Brasz between pump 14 and evaporator/cooler 11. See Brasz, Fig. 1. 3 Appeal 2015-003417 Application 13/459,979 Appellants assert that “the principle of operation of Brasz requires that the liquid refrigerant flash across the cold plate 22 of Brasz into vapor refrigerant that is subsequently condensed in the condenser 13.” Appeal Br. 8 (citing Brasz, paras. 29 and 30). Appellants argue that modifying Brasz as proposed by the Examiner would “change the principle of operation of Brasz.” Id. at 7. The Examiner responds that “[t]he principle of operation of Brasz is routing of the working fluid of the Rankine cycle to the power converter to cool it.” Ans. 5 (citing Brasz, Fig. 1). The Examiner notes that although the modification of Brasz changes the location of the power converter in the Rankine cycle system of Brasz, it “does not present a substantial reconstruction and redesign of elements.” Id. The Examiner notes that likewise, the modification based on Horek “does not alter the basic principle of routing the working fluid of the Rankine cycle to the power converter to cool it.” Id. at 6. Appellants reply that cooling in Brasz is performed “using a specific technique, e.g., cooling via flashing,” and that “the key principle of operation is not cooling per se, but how the cooling is structured to occur.” Reply Br. 2. Brasz teaches that “flashing of the refrigerant into the cold plate 22 quickly and substantially reduces the temperature of the cold plate ... and reduces the 1GBT solid state junction temperature dramatically.” Brasz, para. 29 (emphasis added); see also Appeal Br. 8. Brasz also teaches that the dramatic reduction in temperature “allows more current to be passed through the IGBT’S, such that the power switching capacity of the solid 4 Appeal 2015-003417 Application 13/459,979 state hardware increases substantially thereby increasing the power density by 50 to 100%, thus reducing the cost of power conversion equipment by the same percentage.” Id. (emphasis added). As such, flashing in Brasz appears to provide important benefits, including a quick and dramatic temperature reduction. See Appeal Br. 8. Absent evidence that liquid cooling without flashing would provide “the degree of cooling that is desirable in order to allow for the desired power densities in the power converter 17” (Brasz, para. 28), the Examiner has not established sufficiently that one of ordinary skill in the art would have modified Brasz in the manner suggested. That is, even if one having ordinary skill in the art might have contemplated a balancing approach between the power density requirements of Brasz and the efficiency of the Rankine cycle of Jensen (see Answer 9), the Examiner lacks persuasive evidence supporting the position that the benefit gained from an increase in system efficiency, as taught by Jensen, outweighs Brasz’s explicit desire to quickly and substantially reduce the temperature of the cold plate by flashing. Accordingly, we do not sustain the Examiner’s rejection of claims 22—31 over Brasz, Jensen, and Horek. Independent claims 32 and 39 recite substantially similar features to those discussed above regarding claim 22, and claims 33—38 and 40-42 depending from claims 32 and 39, respectively. For the reasons discussed above with respect to the rejection of claim 22 we also do not sustain the Examiner’s rejection of claims 32—42 over the combined teachings of Brasz, Jensen, and Horek. 5 Appeal 2015-003417 Application 13/459,979 DECISION The Examiner’s rejection of claims 22—42 as unpatentable over Brasz, Jensen, and Horek is reversed. REVERSED 6 Copy with citationCopy as parenthetical citation