Multi-engine aircraft power plant with heat recuperation
AssigneePratt & Whitney Canada Corp.
InventorDaniel Alecu
Life of this patent
Estimating the term…
Abstract
Multi-engine aircraft power plants and associated operating methods are disclosed. An exemplary multi-engine power plant comprises a first turboshaft engine and a second turboshaft engine configured to drive a common load such as a rotary wing of an aircraft; and a heat exchanger in thermal communication with an exhaust gas of the first turboshaft engine and in thermal communication with pre-combustion air of the second turboshaft engine. The heat exchanger is configured to permit heat transfer from the exhaust gas of the first turboshaft engine to the pre-combustion air of the second turboshaft engine.
Claims14
A method of operating a multi-engine power plant drivingly coupled to a rotary wing of an aircraft during flight of the aircraft, the method comprising:
- operating a first turboshaft engine of the multi-engine power plant to drive the rotary wing of the aircraft during flight while a second turboshaft engine of the multi-engine power plant is idling;
- transferring heat from an exhaust gas of the first turboshaft engine to pre-combustion air upstream of a combustor of the idling second turboshaft engine of the multi-engine power plant;
- receiving a sensed speed value representative of an actual output speed of the multi-engine power plant where the sensed speed value is lower than a corresponding set point value;
- and
- increasing an output power level of the second turboshaft engine to drive the rotary wing of the aircraft, wherein the first turboshaft engine is operated at a substantially constant output power level while the output power level of the second turboshaft engine is increasing.
A method of operating a multi-engine power plant of an aircraft, the method comprising:
- using a first turboshaft engine of the multi-engine power plant to drive a load while a second turboshaft engine of the multi-engine power plant is idling;
- transferring heat from the first turboshaft engine to pre-combustion air upstream of a combustor of the second turboshaft engine of the multi-engine power plant to assist with the idling of the second turboshaft engine;
- receiving a sensed operating speed of the load that is lower than a corresponding set point value;
- and
- increasing an output power level of the second turboshaft engine, wherein the first turboshaft engine is operated at a substantially constant output power level while the output power level of the second turboshaft engine is increasing.
A multi-engine power plant for an aircraft, the power plant comprising:
- a first turboshaft engine and a second turboshaft engine, the first turboshaft engine and the second turboshaft engine being configured to drive a common load;
- a heat exchanger in thermal communication with an exhaust gas of the first turboshaft engine and in thermal communication with pre-combustion air of the second turboshaft engine, the heat exchanger being configured to, in use, permit heat transfer from the exhaust gas of the first turboshaft engine to the pre-combustion air of the second turboshaft engine;
- a first duct configured to receive the pre-combustion air from a location along a gas path of the second turboshaft engine downstream of a compressor stage of the second turboshaft engine and direct the pre-combustion air toward the heat exchanger;
- a second duct configured to direct the pre-combustion air from the heat exchanger to a location along the gas path of the second turboshaft engine upstream of a combustor of the second turboshaft engine;
- a first control loop configured to control the first turboshaft engine based on a desired output power level of the first turboshaft engine;
- and
- a second control loop configured to:
- control the second turboshaft engine based on the desired operating speed of the common load;
- cause the second turboshaft engine to idle when the desired output power level of the first turboshaft engine is sufficient to maintain the desired operating speed of the common load;
- and
- cause an increase in output power level of the second turboshaft engine when the desired output power level of the first turboshaft engine is insufficient to maintain the desired operating speed of the common load.
Dependencies are inferred from the claim text.