# US 11,994,080 B2 · Heating system for aircraft engine liquid distribution system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,994,080 B2 - Document ID: US11994080B2 - Status: Granted - Kind: B2 - Application number: 17/668,576 - Filed: 2022-02-10 - Published: 2023-08-10 - Granted: 2024-05-28 - Earliest claimed: 2022-02-10 - Assignees: Pratt & Whitney Canada Corp. - Applicants: Pratt & Whitney Canada Corp. - Inventors: Daniel Alecu - Web page: https://patentgrep.com/patent/US11994080B2 ## CPC - F01D 25/20: using lubrication pumps - F02D 41/064: {at cold start (F02D41/067 takes precedence)} - F01D 17/08: responsive to condition of working-fluid, e.g. pressure - F01D 19/02: dependent on temperature of component parts, e.g. of turbine-casing - F01D 25/10: Heating, e.g. warming-up before starting - F02C 7/06: Arrangements of bearings (bearings F16C); Lubricating ({of turbo machines F01D25/18; of machines or} engines in general F01M) - F05D 2220/323: for aircraft propulsion, e.g. jet engines - F05D 2260/98: Lubrication - F05D 2270/303: Temperature - F05D 2270/44: active, predictive, or anticipative - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A heating system for heating a component in a liquid distribution system of an aircraft engine. The liquid distribution system feeds a liquid to the component. The heating system includes an acoustic generator disposed in communication with the component via a liquid passage of the liquid distribution system. The liquid passage defines a length between the acoustic generator and the component. The acoustic generator generates a resonant frequency selected as a function of the length of the liquid passage to generate a standing wave in the liquid within the liquid passage. The standing wave transmitting energy to the component to heat the component. ## Claims ### Claim 1 A heating system for heating a component in a liquid distribution system of an aircraft engine, the liquid distribution system feeding a liquid to the component, the heating system comprising: an acoustic generator disposed in communication with the component via a liquid passage of the liquid distribution system, the liquid passage defining a length between the acoustic generator and the component, the acoustic generator generating a resonant frequency selected as a function of the length of the liquid passage to generate a standing wave in the liquid within the liquid passage, the standing wave transmitting energy to the component to heat the component; wherein the acoustic generator is fluidly coupled to at least one additional component via at least one additional liquid passage of the liquid distribution system; and wherein the acoustic generator generates a multi-frequency signal to generate the standing wave in the liquid passage to heat the component and to generate at least one additional standing wave in the at least one additional liquid passage to heat the at least one additional. ### Claim 2 (depends on 1) The heating system as defined in claim 1, wherein the acoustic generator is one of a piezoceramic, electromagnetic, magneto-strictive, thermo-acoustic, vapor cycle, pneumatic, hydraulic, and mechanic type acoustic generator. ### Claim 3 (depends on 1) The heating system as defined in claim 1, wherein the resonant frequency generated by the acoustic generator is a first resonant frequency of the liquid passage. ### Claim 4 (depends on 3) The heating system as defined in claim 3, wherein the acoustic generator utilizes frequency sweep and active feedback control to tune the first resonant frequency generated by the acoustic generator. ### Claim 5 (depends on 1) The heating system as defined in claim 1, further comprising a control system operatively coupled to the acoustic generator, wherein the acoustic generator is engageable, via the control system, prior to a cold engine start of the aircraft engine. ### Claim 6 (depends on 1) The heating system as defined in claim 1, further comprising one or more temperature sensors disposed in the aircraft engine and a control system operatively coupled to the acoustic generator and the one or more temperature sensors, wherein the acoustic generator is engageable or disengageable, via the control system, when the one or more temperature sensors detect a temperature below or above a predetermined threshold. ### Claim 7 A liquid distribution system for an aircraft engine, comprising: a storage tank for storing a liquid for the liquid distribution system; passages fluidly coupled to the storage tank, at least one of the passages having a component disposed in the at least one of the passages; a pump distributing the liquid throughout the liquid distribution system; and an acoustic generator disposed in the liquid distribution system and fluidly coupled to the component via the at least one of the passages, the at least one of the passages defining a length between the acoustic generator and the component, the acoustic generator generating a resonant frequency selected as a function of the length of the at least one of the passages to generate a standing wave in the liquid within the at least one of the passages, the standing wave transmitting energy to the component to heat the component; wherein the acoustic generator generates a multi-frequency signal to generate one or more additional standing waves in an additional one or more of the passages with components disposed in the additional one or more of the passages. ### Claim 8 (depends on 7) The liquid distribution system as defined in claim 7, wherein the liquid distribution system is an oil distribution system and the component is one of an oil nozzle, oil flow restrictor, oil valve or journal bearing. ### Claim 9 (depends on 7) The liquid distribution system as defined in claim 7, wherein the acoustic generator is one of a piezoceramic, electromagnetic, magneto-strictive, thermo-acoustic, vapor cycle, pneumatic, hydraulic, and mechanic type acoustic generator. ### Claim 10 (depends on 7) The liquid system as defined in claim 7, wherein the resonant frequency generated by the acoustic generator is a first resonant frequency of the at least one of the passages. ### Claim 11 (depends on 10) The liquid distribution system as defined in claim 10, wherein the acoustic generator utilizes frequency sweep and active feedback control to tune the first resonant frequency generated by the acoustic generator. ### Claim 12 (depends on 7) The liquid distribution system as defined in claim 7, further comprising a control system operatively coupled to the acoustic generator, wherein the acoustic generator is engageable, via the control system prior to a cold engine start of the aircraft engine. ### Claim 13 A method for heating a component in a liquid distribution system of an aircraft engine, the component disposed in a passage of the liquid distribution system, the method comprising: determining a resonant frequency of the passage based on a length of the passage defined between an acoustic generator disposed in the passage and the component; and generating, at the acoustic generator, a standing wave in the passage based on the resonant frequency to transmit energy to the component to thereby heat the component, and sweeping for the resonant frequency based on active feedback control. ### Claim 14 (depends on 13) The method as defined in claim 13, further comprising, prior to generating the standing wave, receiving an indication that an engine temperature is below a predetermined threshold. ### Claim 15 (depends on 14) The method as defined in claim 14, further comprising receiving an indication that the engine temperature has reached a predetermined threshold, and, in response, ceasing the generating the standing wave in the passage. ### Claim 16 (depends on 13) The method as defined in claim 13, further comprising determining a resonant frequency of at least one additional passage based on a length of the at least one additional passage defined between the acoustic generator and at least one additional component disposed in the at least one additional passage, wherein the generating the standing wave further includes generating, at the acoustic generator, a multi-frequency signal based on the resonant frequency of the passage and the resonant frequency of the at least one additional passage to produce standing waves in the passage and in the at least one additional passage to transmit energy to the component and the at least one additional component to thereby heat the component and the at least one additional component.