DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 11/30/2023 has been entered.
Claim Rejections - 35 USC § 103
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.
Claims 1, 13, 21, 25, 29 and 31 are rejected under 35 U.S.C. 103 as being unpatentable over Pub. No.: US 2019/0055890 A1 (Ethier) in view of US Patent 7,325,401 B1 (Kesseli ‘401) and Pub. No. US 2009/0228149 A1 (Alston).
Regarding claim 1, Ethier discloses (see fig. 3) a gas turbine engine 101, comprising: one or more turbo-compressor spools (102, 103, 104) each turbo-compressor spool having a compressor 102, a turbine 103, and a first rotatable shaft 104 rotatably coupling the compressor and the turbine; a combustor 105 for receiving a high-pressure airflow from the compressor of each of the turbo-compressor spools and delivering a heated airflow to the turbine of each of the turbo-compressor spools; a free turbine spool (110, 111, 112) comprising a free power turbine 110 and a second rotatable shaft 111, the second rotatable shaft rotatably coupling the free power turbine to a variable speed alternator 112 (the speed varies with the speed of free power turbine 110; alternator is interpreted as “an electric generator for producing alternating current”, Merriam-Webster online), wherein the variable speed alternator generates electrical power (AC power is supplied to rectifier 201), supplying air (air from compressor 102 is combusted with fuel in combustor 105 and the resulting combustion gas is supplied to free turbine 110 via turbine 103; this is similar to applicant fig. 5 wherein the “gas 507 exiting from low pressure turbine 517 … enters free power turbine 521” is stated in par. 71) from a turbine 103 of one of the turbo-compressor spools (102, 103, 104) to the free power turbine; a fuel supply 107 delivering an increased (see par. 130) fuel flow 107 in relation to the increase in airflow (see par. 130; the engine “spooling up”, or in other words increasing in speed, provides more air to the combustor 105 in relation to the instant increase in fuel flow such that the air and fuel can be combusted at 123 shown in fig. 1), wherein a power of the free power turbine increases (see par. 118, middle and bottom); a rectifier 201 (converter 201 is rectifier; see par. [0117]) accepting a frequency output from the variable speed alternator 112, wherein the rectifier converts AC power to DC power (rectifier 201 is an AC to DC converter; see par. 119, top) and delivers the DC power to a DC common bus 203 (Applicant DC bus is interpreted to be the DC link between active rectifier 63 and inverter 64 in Applicant fig. 6; likewise Ethier teaches a DC link 203 between rectifier 201 and inverter 301 wherein converter 301 is an inverter, see par. 117, and thus DC link 203 is a DC common bus wherein the DC common bus 203 provides power to both ultra-capacitors 205 and inverter 301 and as discussed in par. 119, middle, and par. 120, middle, respectively); one or more ultra-capacitors (energy storage 205 may be ultra-capacitor; par. 119, middle; see also par. 117 describing embodiment of fig. 3 using ultra-capacitor with inverter) connected to the DC common bus; and an inverter 301 connecting DC common bus to an AC electrical load 206, wherein the one or more ultra-capacitors provide a transient power boost (ultra-capacitors inject power into DC bus 203, in order to boost the power provided by alternator 112, to immediately compensate for a lack of power from alternator 112 during transient operation of the gas turbine; see pars. 119 and 130) to the inverter (this is interpreted regarding applicant fig. 6 wherein the power boost is provided to the DC link at a location between rectifier 63 and inverter 64; similarly the power boost from ultracapacitors 205 Ethier is provided at the DC link 203 at a location between rectifier 201 and inverter 301). Ethier does not explicitly disclose the free power turbine is fitted with a variable area nozzle upstream of the free power turbine; an actuator for controlling an opening of the variable area nozzle in response to a torque spike, wherein the variable area nozzle provides an increase in airflow aspirated by the engine; an active rectifier; a variable frequency output from the variable speed alternator; and wherein an impedance of the inverter is variable.
Kesseli ‘401 teaches (see the embodiment of figs. 11 and 12) a free power turbine 100 is fitted with a variable area (changing the area changes the flow angle as discussed in col. 8, ll. 10-15; also see fig. 9, top, pointing out that the instant nozzle is variable area type) nozzle 102 upstream (see bold arrows showing direction of gas flow) of the free power turbine; and an actuator 98 for controlling an opening (see col. 9, ll. 1-2: “the variable position nozzle … may be opened incrementally”) of the variable area nozzle in response to a torque spike (Kesseli '401 nozzle is capable of performing this; for example the nozzle is opened when the power is not sufficient (see col. 8, l. 67 to col. 9, l. 2); for example, if more power is needed from the free turbine, than more combusted gases flow through a more open nozzle enroute to the turbine so that the free turbine can provide additional power; a torque spike corresponds to a scenario wherein more power is needed in applicant par. 6; one of ordinary skill understands a torque spike to be a scenario where there is a high torque on the gas turbine engine due to a sudden load demand and Kesseli ‘401 points out a capability of quickly responding power demands at col. 9, ll. 50-55; this is similar to applicant par. 76 wherein responding to a spike is a rapid response; it is noted that fig. 19 also teaches variable area nozzle 271 controlled by actuator 278), wherein the variable area nozzle provides an increase in airflow aspirated by the engine (see col. 8, ll. 20-21: “the actuator 98 positions the nozzle 102 to effect more or less gas flow through the turbine”, thus the variable area nozzle is capable of providing such an increase, wherein the instant gas flow is combusted fuel and air when Kesseli ‘401 is applied to Ethier because the combusted fuel and air pass through the variable area nozzle taught by Kesseli ‘401 enroute to free turbine 110 of Ethier, see location 125 in fig. 1 of Ethier; this is similar to applicant fig. 5 wherein combusted fuel and air, from combustor 515, enter variable area nozzle 524 at 507).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier with the free power turbine is fitted with a variable area nozzle upstream of the free power turbine; an actuator for controlling an opening of the variable area nozzle in response to a torque spike, wherein the variable area nozzle provides an increase in airflow aspirated by the engine as taught by Kesseli ‘401 in order to facilitate achieving the maximum possible electrical power (i.e., maximum efficiency) (see Kesseli ‘401 col. 8, ll. 17-19).
Alston teaches power conversion structures converting power from a generator driven by an engine (see “Generator” in fig. 9 that is driven by engine discussed in par. 40) and further teaches (see fig. 9) an active rectifier accepting a variable frequency output from a variable speed alternator (see pars 40, bottom, and 72; claim 3).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401 with an active rectifier accepting a variable frequency output from a variable speed alternator as taught by Alston in order facilitating providing reliable electrical power equipment (Alston par. [0003]) making use of an active rectifier thereby improving efficiency of rectification compared to passive rectifiers.
Kesseli ‘401 teaches (see the embodiment of figs. 11 and 12) an impedance of an inverter 91 is variable (the impedance of the inverter 91 is varied in order to adjust the speed of the free turbine 100; see col. 7, ll. 55-60, and see fig. 11 at S04).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401 and Alston with an impedance of the inverter is variable as taught by Kesseli ‘401 in order to facilitate operating the free power turbine of Ethier in view of Kesseli ‘401 and Alston at an optimum speed (see Kesseli ‘401, ll. 58-61).
The claim 13 preamble recitation “for overcoming effects of turbo lag” is read as intended use by the examiner and is given little patentable weight. (see MPEP 2111.02(II)). If the body of a claim fully and intrinsically sets forth all of the limitations of the claimed invention, and the preamble merely states, for example, the purpose or intended use of the invention, rather than any distinct definition of any of the claimed invention’s limitations, then the preamble is not considered a limitation and is of no significance to claim construction. Pitney Bowes, Inc. v. Hewlett-Packard Co., 182 F.3d 1298, 1305, 51 USPQ2d 1161, 1165 (Fed. Cir. 1999). Ethier discloses in fig. 3 ultracapacitors 205 that discharge current during transient operations (see pars. 108 and 113) thereby reducing turbo lag (this is consistent with applicant par. 88).
Regarding claim 13, Ethier discloses (see fig. 3) a system and a block loaded gas turbine engine (101; the gas turbine experiences sudden load changes as discussed in pars. 108 and 113; a sudden increase in load is consistent with meaning of block loading at applicant par. 26, top), wherein the gas turbine engine comprises: one or more turbo-compressor spools (102. 103, 104), wherein each turbo-compressor spool has a compressor 102, a turbine 103, and a first rotatable shaft 104 rotatably coupling the compressor and the turbine; a combustor 105 for receiving a high-pressure airflow from the compressor of a first turbo-compressor spool of the turbo-compressor spools and delivering a heated airflow to the turbine of each of the turbo-compressor spools, wherein the heated airflow rotatably drives the first rotatable shaft and the compressor of each of the one or more turbo-compressor spools; a free turbine spool (110, 110, 112) comprising a free power turbine 110 and a second rotatable shaft 111, the second rotatable shaft rotatably coupling the free power turbine to a variable speed alternator 112 (speed varies with free turbine speed), wherein the variable speed alternator generates electrical power (alternator 112 supplies AC to rectifier 201); supplying air (air from compressor 102 is combusted with fuel in combustor 105 and the resulting combustion gas is supplied to free turbine 110 via turbine 103; this is similar to applicant fig. 5 wherein the “gas 507 exiting from low pressure turbine 517 … enters free power turbine 521” is stated in par. 71) from a turbine 103 of one of the turbo-compressor spools (102, 103, 104) to the free power turbine; a rectifier, wherein the rectifier 201 (converter 201 is rectifier; see par. [0117]) accepts a frequency output from the variable speed alternator, converts AC power to DC power (see par. 119, top), and delivers the DC power to a DC common bus 203 (Applicant DC bus is interpreted to be the DC link between active rectifier 63 and active inverter 64 in Applicant fig. 6; likewise Ethier teaches a DC link 203, that is a DC bus, between rectifier 201 and inverter 301 wherein converter 301 is an inverter, see par. 117, wherein the DC common bus 203 provides power to both ultra-capacitors 205 and inverter 301 as discussed in par. 119, middle, and par. 120, middle, respectively); a fuel system 113 delivering an increased (see par. 130) fuel supply 107 in response to (“in response to” is interpreted in accordance with applicant par. 76 to be a combined fuel and air increase) an increase in airflow (see par. 130; the engine “spooling up”, or in other words increasing in speed, provides more air to the combustor 105 in relation to the instant increase in fuel flow such that the air and fuel can be combusted at 123 shown in fig. 1), wherein a power of the free power turbine increases (see par. 118, middle and bottom); one or more ultra-capacitors (energy storage 205 may be ultra-capacitor; par. 119, middle; see also par. 117 describing embodiment of fig. 3 using ultra-capacitor with inverter) connected to the DC common bus; and an inverter 301 connecting DC common bus to an AC electrical load 206, wherein the one or more ultra-capacitors provide a transient power boost (ultra-capacitors inject power into DC bus 203, in order to boost the power provided by alternator 112, to immediately compensate for a lack of power from alternator 112 during transient operation of the gas turbine; see pars. 119 and 130) to the inverter (this is interpreted regarding applicant fig. 6 wherein the power boost is provided to the DC link at a location between rectifier 63 and inverter 64; similarly the power boost from ultracapacitors 205 Ethier is provided at the DC link 203 at a location between rectifier 201 and inverter 301). Ethier does not explicitly disclose the free power turbine is fitted with a variable area nozzle upstream of the free power turbine; an actuator for controlling an opening of the variable area nozzle in response to a torque spike, wherein the variable area nozzle provides an increase in airflow aspirated by the engine; an active rectifier accepts a variable frequency output from the variable speed alternator; and an impedance of the inverter is variable.
Kesseli ‘401 teaches (see the embodiment of figs. 11 and 12) a free power turbine 100 is fitted with a variable area (changing the area changes the flow angle as discussed in col. 8, ll. 10-15; also see fig. 9, top, pointing out that the instant nozzle is variable area type) nozzle 102 upstream (see bold arrows showing direction of gas flow) of the free power turbine; and an actuator 98 for controlling an opening (see col. 9, ll. 1-2: “the variable position nozzle … may be opened incrementally”) of the variable area nozzle in response to a torque spike (Kesseli '401 nozzle is capable of performing this; for example the nozzle is opened when the power is not sufficient (see col. 8, l. 67 to col. 9, l. 2); for example, if more power is needed from the free turbine, than more combusted gases flow through a more open nozzle enroute to the turbine so that the free turbine can provide additional power; a torque spike corresponds to a scenario wherein more power is needed in applicant par. 6; one of ordinary skill understands a torque spike to be a scenario where there is a high torque on the gas turbine engine due to a sudden load demand and Kesseli ‘401 points out a capability of quickly responding power demands at col. 9, ll. 50-55; this is similar to applicant par. 76 wherein responding to a spike is a rapid response; it is noted that fig. 19 also teaches variable area nozzle 271 controlled by actuator 278), wherein the variable area nozzle provides an increase in airflow aspirated by the engine (see col. 8, ll. 20-21: “the actuator 98 positions the nozzle 102 to effect more or less gas flow through the turbine”, thus the variable area nozzle is capable of providing such an increase, wherein the instant gas flow is combusted fuel and air when Kesseli ‘401 is applied to Ethier because the combusted fuel and air pass through the variable area nozzle taught by Kesseli ‘401 enroute to free turbine 110 of Ethier, see location 125 in fig. 1 of Ethier; this is similar to applicant fig. 5 wherein combusted fuel and air, from combustor 515, enter variable area nozzle 524 at 507).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier with the free power turbine is fitted with a variable area nozzle upstream of the free power turbine; an actuator for controlling an opening of the variable area nozzle in response to a torque spike, wherein the variable area nozzle provides an increase in airflow aspirated by the engine as taught by Kesseli ‘401 in order to facilitate achieving the maximum possible electrical power (i.e., maximum efficiency) (see Kesseli ‘401 col. 8, ll. 17-19).
Alston teaches power conversion structures converting power from a generator driven by an engine (see “Generator” in fig. 9 that is driven by engine discussed in par. 40) and further teaches (see fig. 9) an active rectifier accepting a variable frequency output from a variable speed alternator (see pars 40, bottom, and 72; claim 3).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401 with an active rectifier accepting a variable frequency output from a variable speed alternator as taught by Alston in order facilitating providing reliable electrical power equipment (Alston par. [0003]) making use of an active rectifier thereby improving efficiency of rectification compared to passive rectifiers.
Kesseli ‘401 teaches (see the embodiment of figs. 11 and 12) an impedance of an inverter 91 is variable (the impedance of the inverter 91 is varied in order to adjust the speed of the free turbine 100; see col. 7, ll. 55-60, and see fig. 11 at S04).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401 and Alston with an impedance of the inverter is variable as taught by Kesseli ‘401 in order to facilitate operating the free power turbine of Ethier in view of Kesseli ‘401 and Alston at an optimum speed (see Kesseli ‘401, ll. 58-61).
Regarding claims 21 and 25, Ethier in view of Kesseli ‘401 and Alston teach the current invention as claimed and discussed above. Ethier further discloses the ultra-capacitors inject current onto the DC common bus (ultra-capacitors inject power into DC bus 203 to immediately compensate for a lack of power from alternator 112 during transient operation of the gas turbine; see pars. 119 and 130) to reduce voltage fluctuations on the DC common bus (intended use: because the ultracapacitors 205 inject DC power into the common DC bus 203 to accommodate for a lack of power from the alternator 112 voltage fluctuations that would otherwise occur in a scenario without power injection can be reduced).
Regarding claims 29 and 31, Ethier in view of Kesseli ‘401 and Alston teach the current invention as claimed and discussed above. Ethier further discloses the ultra-capacitators are discharged when a block loading event occurs. When a block loading event occurs, or in other words a sudden increase in load or electricity demand from the gas turbine and alternator of Ethier combined with Kesseli ‘401 in view Kesseli ‘519, a response is wherein the ultracapacitors taught by Ethier provide stored energy in the form of DC to the DC common bus of Ethier in view of Kesseli ‘401 in view Kesseli ’51. The supplied electric current supplements the electrical current provided by the alternator of Ethier in view of Kesseli ‘401 in view Kesseli ’51, in an effort to meet the sudden increase in load demand during which time the gas turbine spools up to meet the increasing load (see Ethier par. [0119], middle and bottom).
Claims 2, 4, 5 and 14-16 are rejected under 35 U.S.C. 103 as being unpatentable over Ethier in view of Kesseli ‘401 and Alston, as applied to claims 1, 7 and 13 above, and further in view of Pub. No.: US 2013/0139519 A1 (Kesseli ‘519).
Regarding claims 2 and 14, Ethier in view of Kesseli ‘401 and Alston teach the current invention as claimed and discussed above. Ethier does not explicitly disclose a recuperator or heat exchanger.
Kesseli ‘519 teaches (see fig. 5) a gas turbine engine (par. [0042], top) and further teaches a recuperator 44 or heat exchanger 44.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401 and Alston with a recuperator or heat exchanger as taught by Kesseli ‘519 in order to facilitate recovering waste heat in order to pre-heat air for combustion thereby improving energy efficiency of the gas turbine of Ethier in view of Kesseli ‘401 and Alston (see Kesseli ‘519 par. 5).
Regarding claim 4 and 15, Ethier in view of Kesseli ‘401 and Alston teach the current invention as claimed and discussed above. Ethier does not explicitly disclose an intercooler between the compressor of first turbo-compressor spool of the one or more turbo-compressor spools and the compressor of a second turbo-compressor spool of the one or more turbo-compressor spools.
Kesseli ‘519 teaches (see fig. 5; the labeling of spools and shafts also shown in figs. 1 and 3) an intercooler (see par. 39, top) between a compressor 45 of first turbo-compressor spool 9 of one or more spools (9, 10) and a compressor 22 of a second turbo-compressor spool 10 of the one or more spools.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401 and Alston with an intercooler between the compressor of a first turbo-compressor spool of the one or more turbo-compressor spools and the compressor of a second turbo-compressor spool of the one or more turbo-compressor spools as taught by Kesseli ‘519 in order to facilitate increasing the density of air between compression stages thereby improving compression and engine efficiency (see Kesseli ‘519 par. 5) wherein a second turbo-compressor spool results in less weight of the individual spools thereby reducing the effects of turbo lag.
Regarding claims 5 and 16, Ethier in view of Kesseli ‘401 and Alston teach the current invention as claimed and discussed above. Ethier does not explicitly disclose the turbine of each of the turbo-compressor spools comprises a ceramic material.
Kesseli ‘519 teaches (see fig. 5) a turbine (high pressure turbine 42) of a turbo-compressor spool 10 comprises a ceramic material (see par. 57).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401 and Alston with each turbine comprises a ceramic material as taught by Kesseli ‘519 in order to facilitate using a light weight material in the turbines thereby reducing turbo lag and reducing amount of cooling air needed (see Kesseli ‘519 par. 57).
Claims 7, 24 and 30 are rejected under 35 U.S.C. 103 as being unpatentable over Ethier in view of Kesseli ‘401, US Patent 2,912,824 (Van Nest) and Alston.
Regarding claim 7, Ethier discloses (see fig. 3) a method of operating a gas turbine engine 101, the method comprising: receiving, by a combustor 105, a high-pressure air flow from a compressor 102 of a first turbo-compressor spool (102, 103, 104) of one or more turbo-compressor spools, wherein the first turbo-compressor spool of the one or more turbo-compressor spools comprises the compressor 102, a turbine 103, and a first rotatable shaft 104 rotatably coupling the compressor and the turbine; delivering, by the combustor, a heated airflow to the turbine of the first turbo-compressor spool of the one or more turbo-compressor spools, wherein the heated airflow rotatably drives the first rotatable shaft and the compressor of the first turbo-compressor spool of the one or more turbo-compressor spools; generating, by a variable speed alternator 112 (the speed varies with the speed of free power turbine 110), electrical power (AC power is supplied to rectifier 201), wherein the variable speed alternator is rotatably coupled to a free turbine spool (110, 11, 112) comprising a free power turbine 110 and a second rotatable shaft 111; wherein the free power turbine is supplied air (air from compressor 102 is combusted with fuel in combustor 105 and the resulting combustion gas is supplied to free turbine 110 via turbine 103; this is similar to applicant fig. 5 wherein the “gas 507 exiting from low pressure turbine 517 then passes through variable area nozzle 524 and enters free power turbine 521” is stated in par. 71) from a turbine 103 of one of the turbo-compressor spools, increasing (see par. 130) fuel flow 107 in response to an increase in airflow aspirated by the engine (see par. 130; the engine “spooling up”, or in other words increasing in speed, provides more air to the combustor 105 in relation to the instant increase in fuel flow such that the air and fuel can be combusted at 123 shown in fig. 1), wherein a power of the free power turbine increases (see par. 118, middle and bottom); accepting, by an rectifier 201 (converter 201 is rectifier; see par. [0117]), a frequency output from the variable speed alternator; converting, by the rectifier, the electrical power from AC power to DC power (rectifier 201 is an AC to DC converter; see par. 119, top); delivering, by the rectifier, the DC power to a DC common bus 203 (Applicant DC bus is interpreted to be the DC link between active rectifier 63 and active inverter 64 in Applicant fig. 6; likewise Ethier teaches a DC link 203, that is a DC bus, between rectifier 201 and inverter 301 wherein converter 301 is an inverter, see par. 117, wherein the DC common bus 203 provides power to both ultra-capacitors 205 and inverter 301 as discussed in par. 119, middle, and par. 120, middle, respectively), wherein one or more ultra-capacitors (energy storage 205 may be ultra-capacitor; par. 119, middle; see also par. 117 describing embodiment of fig. 3 using ultra-capacitor with inverter) are connected to the DC common bus; and converting, with an inverter 301 connecting the DC common bus 203 to an AC electrical load 206, the DC power to AC power, wherein the one or more ultra-capacitors provide a transient power boost (ultra-capacitors inject power into DC bus 203, in order to boost the power provided by alternator 112, to immediately compensate for a lack of power from alternator 112 during transient operation of the gas turbine; see pars. 119 and 130) to the inverter (this is interpreted regarding applicant fig. 6 wherein the power boost is provided to the DC link at a location between rectifier 63 and inverter 64; similarly the power boost from ultracapacitors 205 Ethier is provided at the DC link 203 at a location between rectifier 201 and inverter 301). Ethier does not explicitly disclose wherein the free power turbine is fitted with a variable area nozzle upstream of the free power turbine; controlling, by an actuator, an opening of the variable area nozzle in response to a torque spike, wherein the variable area nozzle provides an increase in airflow aspirated by the engine; an active rectifier; a variable frequency output from the variable speed alternator; and an impedance of the inverter is variable.
Kesseli ‘401 teaches (see the embodiment of figs. 11 and 12) a free power turbine 100 is fitted with a variable area nozzle 102, wherein the variable area (changing the area changes the flow angle as discussed in col. 8, ll. 10-15; also see fig. 9, top, pointing out that the instant nozzle is variable area type) nozzle upstream of the free power turbine; controlling, by an actuator 98, an opening (see col. 9, ll. 1-2: “the variable position nozzle … may be opened incrementally”) of the variable area nozzle. It is noted that fig. 19 also teaches variable area nozzle 271 controlled by actuator 278, wherein the variable area nozzle provides an increase in airflow aspirated by the engine (see col. 8, ll. 20-21: “the actuator 98 positions the nozzle 102 to effect more or less gas flow through the turbine”, thus the variable area nozzle of provides such an increase, wherein the instant gas flow is combusted fuel and air when Kesseli ‘401 is applied to Ethier because the combusted fuel and air pass through the variable area nozzle taught by Kesseli ‘401 enroute to free turbine 110 of Ethier, see location 125 in fig. 1 of Ethier; this is similar to applicant fig. 5 wherein combusted fuel and air, from combustor 515, enter variable area nozzle 524 at 507).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier with the free power turbine is fitted with a variable area nozzle upstream of the free power turbine; controlling, by an actuator, an opening of the variable area nozzle, wherein the variable area nozzle provides an increase in airflow aspirated by the engine as taught by Kesseli ‘401 in order to facilitate achieving the maximum possible electrical power (i.e., maximum efficiency) (see Kesseli ‘401 col. 8, ll. 17-19).
Van Nest teaches (see figure) a gas turbine (see col. 2, l. 40) and further teaches controlling an opening of a variable area nozzle 5 in response to a torque spike (the variable nozzle “quickly” responds to rapid changes in power requirements of the gas turbine; see col. 1, ll. 45-50 and ll. 65-70; this is similar to applicant “fast” acting variable area nozzle in par. 78).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401 with controlling the variable area nozzle in response to a torque spike as taught by Van Nest in order to facilitate providing quick and flexible control of power output in response to the block loading scenarios of Ethier (i.e., torque spikes of gas turbine 101 of Ethier wherein the gas turbine experiences sudden load changes as discussed in pars. 108 and 112) (see Van Nest col. 2, ll. 45-50).
Alston teaches power conversion structures converting power from a generator driven by an engine (see “Generator” in fig. 9 that is driven by engine discussed in par. 40) and further teaches (see fig. 9) an active rectifier accepting a variable frequency output from a variable speed alternator (see pars 40, bottom, and 72; claim 3).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401 and Van Nest with an active rectifier accepting a variable frequency output from a variable speed alternator as taught by Alston in order facilitating providing reliable electrical power equipment (Alston par. [0003]) making use of an active rectifier thereby improving efficiency of rectification compared to passive rectifiers.
Kesseli ‘401 teaches (see the embodiment of figs. 11 and 12) an impedance of an inverter 91 is variable (the impedance of the inverter 91 is varied in order to adjust the speed of the free turbine 100; see col. 7, ll. 55-60, and see fig. 11 at S04).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401, Van Nest and Alston with an impedance of the inverter is variable as taught by Kesseli ‘401 in order to facilitate operating the free power turbine of Ethier in view of Kesseli ‘401 and Alston at an optimum speed (see Kesseli ‘401, ll. 58-61).
Regarding claim 24, Ethier in view of Kesseli ‘401, Van Nest and Alston teach the current invention as claimed and discussed above. Ethier further discloses the ultra-capacitors inject current onto the DC common bus (ultra-capacitors inject power into DC bus 203 to immediately compensate for a lack of power from alternator 112 during transient operation of the gas turbine; see pars. 119 and 130) to reduce voltage fluctuations on the DC common bus (intended use: because the ultracapacitors 205 inject DC power into the common DC bus 203 to accommodate for a lack of power from the alternator 112 voltage fluctuations that would otherwise occur in a scenario without power injection can be reduced).
Regarding claim 30, Ethier in view of Kesseli ‘401, Van Nest and Alston teach the current invention as claimed and discussed above. Ethier further discloses the ultra-capacitators are discharged when a block loading event occurs. When a block loading event occurs, or in other words a sudden increase in load or electricity demand from the gas turbine and alternator of Ethier combined with Kesseli ‘401 in view Kesseli ‘519, a response is wherein the ultracapacitors taught by Ethier provide stored energy in the form of DC to the DC common bus of Ethier in view of Kesseli ‘401 in view Kesseli ’51. The supplied electric current supplements the electrical current provided by the alternator of Ethier in view of Kesseli ‘401 in view Kesseli ’51, in an effort to meet the sudden increase in load demand during which time the gas turbine spools up to meet the increasing load (see Ethier par. [0119], middle and bottom).
Claims 8, 10 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Ethier in view of Kesseli ‘401, Van Nest and Alston, as applied to claim 7 above, and further in view of Kesseli ‘519.
Regarding claim 8, Ethier in view of Kesseli ‘401, Van Nest and Alston teach the current invention as claimed and discussed above. Ethier does not explicitly disclose a heat exchanger.
Kesseli ‘519 teaches (see fig. 5) a gas turbine engine (par. [0042], top) and further teaches a heat exchanger 44.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401, Van Nest and Alston with a heat exchanger as taught by Kesseli ‘519 in order to facilitate recovering waste heat in order to pre-heat air for combustion thereby improving energy efficiency of the gas turbine of Ethier in view of Kesseli ‘401 and Alston (see Kesseli ‘519 par. 5).
Regarding claim 10, Ethier in view of Kesseli ‘401, Van Nest and Alston teach the current invention as claimed and discussed above. Ethier does not explicitly disclose an intercooler between the compressor of first turbo-compressor spool of the one or more turbo-compressor spools and the compressor of a second turbo-compressor spool of the one or more turbo-compressor spools.
Kesseli ‘519 teaches (see fig. 5; the labeling of spools and shafts also shown in figs. 1 and 3) an intercooler (see par. 39, top) between a compressor 45 of first turbo-compressor spool 9 of one or more spools (9, 10) and a compressor 22 of a second turbo-compressor spool 10 of the one or more spools.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401, Van Nest and Alston with an intercooler between the compressor of a first turbo-compressor spool of the one or more turbo-compressor spools and the compressor of a second turbo-compressor spool of the one or more turbo-compressor spools as taught by Kesseli ‘519 in order to facilitate increasing the density of air between compression stages thereby improving compression and engine efficiency (see Kesseli ‘519 par. 5) wherein a second turbo-compressor spool results in less weight of the individual spools thereby reducing the effects of turbo lag.
Regarding claim 11, Ethier in view of Kesseli ‘401, Van Nest and Alston teach the current invention as claimed and discussed above. Ethier does not explicitly disclose the turbine comprises a ceramic material.
Kesseli ‘519 teaches (see fig. 5) a turbine (high pressure turbine 42) comprises a ceramic material (see par. 57).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401, Van Nest and Alston with each turbine comprises a ceramic material as taught by Kesseli ‘519 in order to facilitate using a light weight material in the turbines thereby reducing turbo lag and reducing amount of cooling air needed (see Kesseli ‘519 par. 57).
Claim 23 is rejected under 35 U.S.C. 103 as being unpatentable over Ethier in view of Kesseli ‘401 and Alston, as applied to claim 1 above, and further in view of Pub. No. US 2013/0313826 A1 (Gupta).
Regarding claims 23, Ethier in view of Kesseli ‘401 and Alston teach the current invention as claimed and discussed above. Ethier does not explicitly disclose the DC common bus is connected to a DC electrical load.
Gupta teaches (see fig. 2) a turbine (see par. 53) driven alternator 101 and further teaches DC common bus 112 is connected to a DC electrical load 114.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401 and Alston with the DC common bus is connected to a DC electrical load as taught by Gupta in order to facilitate preventing damage to power components (see Gupta par. 6).
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Ethier in view of Kesseli ‘401, Van Nest and Alston, as applied to claim 7 above, and further in view of Gupta.
Regarding claim 27, Ethier in view of Kesseli ‘401, Van Nest and Alston teach the current invention as claimed and discussed above. Ethier does not explicitly disclose the DC common bus is connected to a DC electrical load.
Gupta teaches (see fig. 2) a turbine (see par. 53) driven alternator 101 and further teaches DC common bus 112 is connected to a DC electrical load 114.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the current invention to provide Ethier in view of Kesseli ‘401, Van Nest and Alston with the DC common bus is connected to a DC electrical load as taught by Gupta in order to facilitate preventing damage to power components (see Gupta par. 6).
Response to Arguments
Applicant's arguments filed 11/30/2023 have been fully considered but they are not persuasive. Applicant argues that the cited references do not disclose or teach "free power turbine fitted with a variable area nozzle upstream of the free power turbine for supplying air from a turbine of [a] turbo-compressor spool to the free power turbine; [and] an actuator for controlling an opening of the variable area nozzle in response to a torque spike". In response, Kesseli ‘401 teaches (see the embodiment of figs. 11 and 12) a free power turbine 100 is fitted with a variable area (changing the area changes the flow angle as discussed in col. 8, ll. 10-15; also see fig. 9, top, pointing out that the instant nozzle is variable area type) nozzle 102 upstream (see bold arrows showing direction of gas flow) of the free power turbine and an actuator 98 for controlling an opening (see col. 9, ll. 1-2: “the variable position nozzle … may be opened incrementally”) of the variable area nozzle in response to a torque spike. A torque spike is an increase in torque of the gas turbine due to an increase in power demand. The Kesseli ‘401 variable area nozzle 102 is controlled by actuator 98 in response to an increase in load wherein the variable nozzle is capable of “quickly” ramping up in response to power demands (see col. 9, ll. 45-55) wherein the variable nozzle is opened in response to increased power demand (col. 8, l. 66 to col. 9, l. 2). Further details are provided in the 103 section above regarding the claims 1 and 13 analyses. Regarding method claim 7, reference Van Nest is cited in the 103 section above to explicitly teach a variable turbine nozzle that reacts rapidly to changes in power demand such as a torque spike (see col. 1, ll. 45-50 and ll. 65-70).
Applicant further argues the cited references do not disclose or teach “wherein the variable area nozzle provides an increase in airflow aspirated by the engine; [and] a fuel supply delivering an increased fuel flow in relation to the increase in airflow, wherein a power of the free power turbine increases”. In response, Kesseli ‘401 teaches in fig. 12 a variable area nozzle provides an increase in airflow aspirated by an engine (see col. 8, ll. 20-21: “the actuator 98 positions the nozzle 102 to effect more or less gas flow through the turbine”, thus the variable area nozzle provides such an increase, wherein the instant gas flow is combusted fuel and air in the scenario wherein Kesseli ‘401 is applied to Ethier because the combusted fuel and air pass through the variable area nozzle taught by Kesseli ‘401 enroute to free turbine 110 of Ethier (see fig. 1 of Ethier below). This is similar to applicant fig. 5 wherein combusted fuel and air, from combustor 515, enter variable area nozzle 524 at 507.
In further response, Ethier discloses a fuel supply 106 delivering an increased (see par. 130) fuel flow 107 in relation to the increase in airflow (see par. 130; the engine “spooling up”, or in other words increasing in speed, provides more air to the combustor 105 in relation to in the instant increase in fuel flow such that the air and fuel can be combusted at 123 shown in fig. 1), wherein a power of the free power turbine increases (see par. 118, middle and bottom). Paulson (US Patent 5,203,164) explains that when a fan or compressor (fan blades 42 of turbofan wheel 34) “spools up”, this causes more air to be provided by the fan (see col. 7, ll. 8-11).
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[AltContent: textbox (increased airflow 122 and fuel flow 109 is combusted 123 and then the resulting increased combustion gas 124 is provided to free turbine 110 by the variable area nozzle at this location taught by Kesseli ‘401; this is similar to applicant fig. 5)][AltContent: arrow]
Conclusion
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/M.J.A/Examiner, Art Unit 3741
/TODD E MANAHAN/Supervisory Patent Examiner, Art Unit 3741