349 results about "Heat engine" patented technology

The invention provides a rotary table bearing-torque motor thermal vibration coupling modeling method, and relates to the technical field of machine tool reliability analysis. Comprising the steps of calculating bearing restoring force, torque and elastic rigidity; giving a dynamic balance equation of the main shaft system; unbalanced magnetic pulling force and unbalanced mass excitation are calculated; a displacement field is solved, and load changes caused by the displacement field are transmitted to the thermal model; the contact force borne by the bearing is updated by considering the load effect related to displacement, and the friction heat generation of the bearing and the heat generation of each part of the motor are calculated; calculating thermal deformation and thermal displacement of the bearing; thermal resistance among nodes is calculated, and a temperature field equilibrium equation is given through a thermal resistance network to achieve rapid thermal-mechanical coupling analysis; the thermal equilibrium equation is solved to calculate temperature response; importing the latest temperature into the kinetic model; lubricating grease viscosity and bearing thermal deformation are updated; and repeating the steps to finally obtain the main shaft displacement field and temperature field response. The method is high in accuracy, high in universality, low in test cost and high in test efficiency.

The invention provides a spindle constant-temperature AI closed-loop heat engine system, and relates to the technical field of numerical control machine tool control and heat management. The invention aims to solve the problems of response lag, uncontrollable thermal stress, single heating strategy and the like of the traditional spindle heat engine method. The system comprises a multi-dimensional thermal state sensing module used for constructing a multi-node discrete temperature field representing the overall thermal distribution of the main shaft; the real-time heat balance feedback module is used for judging the cold / hot starting state of the main shaft according to the initial temperature difference and executing a differentiated feedback control strategy; and an AI prediction forward compensation module that predicts a future cutting thermal load by pre-reading a machining instruction and generates a feedforward thermal compensation instruction. According to the method, the thermal stress is controlled by introducing the radial thermal gradient index as the safety constraint, negative precooling or positive preheating is achieved in combination with the AI predictive capacity, a feedback and feedforward composite control mode is formed, and the dynamic thermal stability and the machining precision of the main shaft under the complex working condition are improved.

The application discloses a brake interface wear and fatigue crack prediction method based on complete thermal-mechanical coupling, comprising the following steps: S1, establishing a finite element model, and discretizing total analysis time into multiple time periods; S2, starting finite element analysis, and calculating interface node contact pressure and node slip rate; S3, performing transient thermal-mechanical coupling analysis; S4, calculating node wear depth and wear direction, and updating grid information by using ALE technology; S5, judging whether the interface contact state is stable convergence; S6, ending analysis, unloading brake load, and obtaining brake disc residual stress; and S7, presetting a crack at the maximum residual stress, simulating crack propagation behavior, calculating stress intensity factor and brake disc fatigue life. The application can simulate tribological behaviors such as contact stress, temperature and wear, and realizes brake disc fatigue life prediction by taking residual stress after the thermal-mechanical coupling process as load input.

The present disclosure provides a solution for a system and a method for converting heat into work. The solution makes use of a nozzle, in which pressurized heat transfer liquid (HTL) and a Liquid-Vapor-Phase-Changing (LVPhC) working fluid is about the same pressure are mixed to form a LVPhC-HTL mixture, which in turn undergoes evaporation and isothermal or quasi-isothermal expansion while flowing in the nozzle that results in acceleration of the mixture. The accelerated mixture is ejected from to thereby rotate a turbine and produce work from the generated kinetic energy. The LVPhC is separated from the mixture and condensed after its ejection from the nozzle and its pressure is elevated back to the working pressure in the nozzle. The present solution exploits the thermodynamic advantages of each phase of the LVPhC.

The invention relates to a variable-power scale-free boiler and topology heat transfer quasi-super Stirling ecological heat engine technology, in particular to a working principle of direct-current scale-free super heat exchange high power density reaching 8-16 times fuel oil stress application variable power in the ZL2012105664497.4 patent achievement innovation field of the inventor, and the working principle is applied to normal low pressure, middle high pressure, critical pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure, high pressure and high pressure. Various types of boilers are free of scale obstruction, super in heat exchange, high in power density, ultra-low in cost rate, and safe in multi-module unit combination of less than 30-90L; a boiler heat exchange heat output'boiler 'system formed by connecting ten to hundreds of congruent module (tube panel) units in parallel is integrally matched with a magnesium catalysis water-based combustion-supporting combustion science'boiler' system of a '8-16 times fuel oil stress application 'Stirling'heat engine', and meanwhile, a new era of human cosmic rock planet carbon dioxide and carbon rock particle energy ecological metallurgy is created. The invention relates to a Stirling ecological heat engine, in particular to a variable-power scale-free multi-module once-through boiler and a topology heat transfer Stirling ecological heat engine, wherein the variable-power scale-free multi-module once-through boiler and the topology heat transfer Stirling ecological heat engine are used for gathering metamorphosis heat radiation and a three-guide interlining heat transfer and exchange body heat output system under the constraint of extreme-effect

The invention provides a double-rotor direct-drive coaxial reverse-propeller electric ducted fan, which is characterized in that a single motor with an inner rotor and an outer rotor directly drives two pairs of blades, an intermediate transmission device and an inner rotor excitation group to generate a rotating magnetic field, and a first-stage propulsion component and a second-stage propulsion component with the same rotational inertia are driven under the action of electromagnetic torque with the same acting force and counter-acting force; one-way rotation deflection torque is balanced, and coaxial reverse propeller movement is achieved; the rectification duct reduces the induced resistance of the blades and improves the propulsive efficiency, the convergence and expansion guide sleeve and the motor frame body dissipate heat to form circulating heat dissipation of the Brayton heat engine, meanwhile, air is heated, expanded and ejected out to generate thrust, the efficiency is high, and the thrust is large. The dual-rotor motor direct-driven coaxial reverse propeller ducted fan propulsion unit is simple in mechanism, light in structure, large in power-to-weight ratio, high in reliability, beneficial to use in a narrow space and vertical take-off and landing, especially suitable for an EVTOL (electric vertical take-off and landing aircraft), and capable of promoting popularization of small aircrafts and vertical take-off and landing urban transportation carriers.

A closed working fluid type heat engine (100) for power generation in the environment of a nuclear fusion power system (200). The heat engine includes a primary heat exchanger (102) connected to a primary heat source (106) and a secondary heat exchanger (108) connected to a secondary heat source (110). The secondary heat source is thermally independent of the primary heat source, and the temperature of the primary heat source is higher than that of the secondary heat source. The heat engine also includes a main turbine (104) and an auxiliary turbine (116). The turbines are arranged in fluid parallel, and a parallel shunt point is arranged between the primary heat exchanger and the secondary heat exchanger. The main turbine receives the working fluid heated by the secondary heat exchanger and the main heat exchanger, and the auxiliary turbine receives the working fluid heated by the secondary heat exchanger. The heat engine also includes a first regenerator (124) configured to thermally connect working fluid flowing out of the main turbine with working fluid flowing into the main heat exchanger. Suitable nuclear fusion power systems and methods of operation thereof are also described.

The present application relates to a flue gas low-heat recovery system based on reverse Brayton cycle heat pump energy storage and a control method thereof, and belongs to the technical field of heat pump energy storage peak shaving of heat engine units. The system comprises a boiler module, a high-heat cycle module and a low-heat cycle module, and realizes the hierarchical utilization of high-grade and low-grade flue gas low-heat through collaborative operation. The flue gas of the boiler module is coupled with the high-heat cycle module through a molten salt heat exchanger, and the low-heat cycle module utilizes the low-heat of the flue gas to generate power through an organic Rankine cycle. The high-heat cycle module stores electric energy and thermal energy during off-peak hours and releases energy during peak hours, thereby improving the peak shaving capacity of the system. The present application realizes the deep integration of efficient recovery of flue gas low-heat and energy storage technology, significantly improves the energy utilization efficiency, system flexibility and economy, and has environmental protection and sustainable development benefits.

The invention discloses a starting method, device and equipment of a fuel cell engine and a storage medium. The starting method comprises the steps that when the fuel cell engine is in a cold engine starting state with the environment temperature larger than 0 DEG C, the fuel cell engine is controlled to execute a heat engine mode; when the pile cooling liquid outlet temperature reaches a first target temperature, obtaining an intercooler cooling liquid inlet temperature and an intercooler cooling liquid outlet temperature; and when the temperature of the intercooler cooling liquid inlet is lower than the temperature of the intercooler cooling liquid outlet, the fuel cell engine is controlled to enter a load pulling mode. According to the technical scheme, it is ensured that the temperature condition of the fuel cell engine rapidly reaches the target value before rapid load pulling, the fault that the fuel cell engine directly enters the load pulling mode and liquid water forms pile flooding due to current increase is avoided, rapid engine heating is achieved, and meanwhile normal work of the fuel cell engine is ensured.

The invention discloses an engine oil temperature control lubricating system for a hybrid electric vehicle, and belongs to the field of engine lubricating systems. Comprising a main oil duct, an engine oil pan, an engine oil pump and an oil duct pipe set, the engine oil pan is used for storing engine oil, the engine oil pump is used for pumping the engine oil in the engine oil pan, and the oil duct pipe set communicates with the engine oil pump and the main oil duct and comprises a first oil duct and a second oil duct which are arranged in parallel; the heater is opened to heat engine oil flowing through the first oil duct when the engine oil temperature is lower than a second preset temperature, and is closed when the engine oil temperature is higher than or equal to the second preset temperature; and the second oil duct comprises a second temperature control valve, and the second temperature control valve is opened when the temperature of the engine oil is larger than or equal to the second preset temperature, so that the engine oil further flows into the main oil duct through the second oil duct. When the engine of the hybrid electric vehicle is in cold start, the temperature of the engine oil can be rapidly increased through the heating piece, so that abnormal sound and abrasion of the engine when the temperature of the engine oil is too low can be well improved.

The utility model relates to an energy-saving and environment-friendly screw type steam compressor testing device, which comprises an air suction filter, an exhaust separator, a heat recoverer, a lubricating oil tank, a softened water tank and a softened water treatment device, an air suction silencer and an air exhaust silencer are respectively arranged on the compressor air exhaust pipe and the compressor air inlet pipe; the compressor air inlet pipe is connected with the exhaust separator through a circulating water spraying pipeline; the heat recoverer is connected with the softened water tank through a condensate pipe and a balance pipe, the softened water treatment device is connected with the softened water tank, and the softened water tank supplements water to the screw type steam compressor to be tested through a softened water supplementing pipe. The steam generation speed of the air dynamic heat engine is increased through the circulating water spraying pipeline, the dynamic heat engine time is short, and meanwhile the power consumption of the driving motor is reduced; the noise reduction effect is good, the noise reduction cost is greatly reduced, and meanwhile, the field working environment of the test device is greatly improved; through the condensation phase change white smoke elimination technology of the heat recoverer, the heat in the steam can be completely recycled.

The invention relates to the technical field of cable production and manufacturing and automation control, in particular to an energy-saving cable extrusion production process control system, which comprises a data acquisition module for acquiring real-time working condition parameters of an extrusion production line; the rheological thermal coupling analysis module is used for resolving the shear heat contribution rate under the current working condition; the heat engine response decoupling module is used for determining a heat engine response lag time difference between mechanical shear heat and machine barrel heat conduction; the energy efficiency optimization calculation module is configured to generate a dynamic heat balance control strategy aiming at an unsteady state working condition according to the heat engine response lag time difference and a preset unit output ratio energy consumption target; the self-adaptive execution module is configured to output a cooperative control instruction for a heating and cooling system and a screw driving system based on the dynamic heat balance control strategy so as to realize minimization of system energy consumption; according to the method, the common energy confrontation phenomenon of alternate operation of heating and cooling in traditional control is solved, and the energy consumption in the transition process is greatly reduced.

An aircraft propulsion system includes a hybrid-electric power plant for delivering power to an air mover for propelling an aircraft. The hybrid-electric power plant includes a heat engine operatively connected to a first air mover, and an electric motor operatively connected to a second air mover. The second air mover is positioned on a wing of the aircraft outboard from the heat engine. A method for reducing trailing vortices includes powering a first air mover of an aircraft with a heat engine during a take-off stage, a climb stage, a cruise-stage and / or a descent stage. The method includes powering a second air mover of the aircraft with an electrical motor during the take-off stage and / or the climb stage. The method includes freewheeling the second air mover during the cruise stage and / or the descent stage to generate mechanical energy and reduce wing tip vortices.

The invention discloses a numerical control gear hobbing machine tooth thickness compensation method and device and a numerical control gear hobbing machine. The numerical control gear hobbing machine tooth thickness compensation method comprises the following steps that the first angle variable quantity of an encoder and the common normal variable quantity of a test workpiece which are determined and obtained through a test are obtained; calculating the radius according to the first angle variable quantity and the common normal variable quantity of the test workpiece; in response to a received heat engine cutting instruction, acquiring an angle value of the encoder when the machine tool is at a zero position, an X coordinate value of the machine tool in a heat engine state and an angle value of the encoder at the position, and calculating to obtain a second variable quantity of the encoder on an X axis in the heat engine state; according to the second variable quantity, the Z-axis coordinate of the tooth width center of the workpiece to be machined and the Z-axis coordinate of the gear rack meshing point, a cutting compensation value is obtained through calculation; and compensating the X axis of the cutter according to the cutting compensation. The cutting compensation amount can be calculated, the compensation precision is high, and time and labor are saved.

A method of regenerating an electric power storage unit for an aircraft hybrid electric propulsion (HEP) system is provided. The HEP system includes a thermal engine, an electric motor, an electric power storage unit, a primary gearbox, and a propulsion unit. The electric motor is configured to selectively provide rotational drive to the propulsion unit. The method includes: controlling the electric motor to operate as the generator; controlling the primary gearbox to be in an output disengaged configuration, wherein in the output disengaged configuration the primary gearbox is disengaged from driving the propulsion unit and the primary gearbox is transfers rotational drive produced by the thermal engine to the electric motor; operating the thermal engine to drive the primary gearbox in the output disengaged configuration; and regenerating the electric power storage unit by providing electrical energy produced by the electric motor to the electric power storage unit.

The invention belongs to the technical field of blast furnace decarburization systems, and particularly discloses a hydrogen-rich carbon circulating blast furnace top gas carbon dioxide capture solution vacuum phase change regeneration system which comprises an absorption tower, a flash tank and a regeneration tower, the bottom and the top of the absorption tower are communicated with a top gas pipe and an ammonia liquid inlet pipe respectively, and a decarburized gas outlet pipe is arranged at the top of the absorption tower; a bottom outlet of the flash tank is communicated with a regeneration tower through a pipeline; a bottom outlet of the regeneration tower is communicated with an evaporator; one side of the evaporator is communicated with a vacuum pipe; one end of the vacuum pipe is communicated with a vacuum phase change direct heating machine; and a cooling unit for cooling the vacuum tube is arranged outside the vacuum tube. The problems that a traditional amine liquid regeneration method is low in regeneration efficiency and high in energy consumption are solved. By combining vacuum flash evaporation, the regeneration efficiency of the amine liquid is remarkably improved, meanwhile, energy consumption and amine liquid loss are reduced, and the purpose of low-carbon metallurgy is achieved.

There is disclosed a method of controlling a helicopter (1) comprising: at least one thermal engine (11); at least one rotor (3), which is operatively connectable to thermal engine (11) to be drive, in use, at a set rotational speed (ωSET); an emergency system (40) comprising: at least one electric motor (41), which is operatively connectable to rotor (3) and an electrical power source (42), which is electrically connected to electric motor (41); the method comprises the steps of i) operatively connecting thermal engine (11) to rotor (3) and keeping electric motor (41) disconnected by rotor (3) or idle, in a normal operating condition of thermal engine (11); ii) detecting if thermal engine (11) is in at least partial failure condition; iii) accelerating electric motor (41) up to when said current rotational speed (ω) equals set value (ωSET), in case of at least partial failure of said thermal engine (11); step iii) comprises the steps of iv) sensing a plurality of parameters (ω, ωERR, ϕ, ϕERR, IIT, ττ / S, τMGB, Powerτ / S, PowerMGB) of thermal engine (11) and rotor (3); and v) identifying an at least partial failure of thermal engine (11), on the basis of parameters (ω, ωERR, ϕ, ϕERR, IIT, τ, P.

The utility model discloses a Stirling heat engine teaching aid based on an auxiliary magnetic suspension system and a U-shaped liquid column, which comprises a support table, a glass U-shaped tube and a quartz tube, a high-frequency induction heater is arranged on the upper side of the support table, a heating induction coil of the high-frequency induction heater is sleeved on the quartz tube, the quartz tube is horizontally arranged, and the glass U-shaped tube is arranged on the quartz tube. A first sealing plug and a second sealing plug are respectively plugged at the two ends of the quartz tube, heat preservation steel wool is arranged at one section, close to the first sealing plug, of the interior of the quartz tube, and a heating iron ring is arranged in the center of the interior of the quartz tube and is positioned in a heating induction coil of the high-frequency induction heater. According to the utility model, through the design of the auxiliary magnetic suspension system and the U-shaped liquid column, the friction between the piston and the pipe wall is greatly reduced, the energy loss in the mechanical energy conversion process is effectively reduced, and the working principle of the Stirling heat engine and the application of the second law of thermodynamics can be intuitively displayed.

A heat engine 10, such as a gas turbine engine, has a controller 290 and a combustor, for example an afterburner combustor 120. The combustor has at least one fuel injection port 128 and at least one pilot ignition device 130. In use, the controller mitigates thermoacoustic instabilities in a gas flow, A, B within the heat engine by selectively energising the at least one pilot ignition device to ignite fuel discharged from the at least one fuel injection port. The heat engine can include a plurality of fuel injection ports radially distributed (170 Fig. 4) with respect to a centreline (9 Fig. 4) of the heat engine and can include a plurality of fuel injection ports angularly distributed (130 Fig. 4) around the centreline of the heat engine. The arrangement delivers a flame (139 Fig. 4) resulting from energisation of the at least one pilot igniting fuel discharged from the at least one fuel injection port, and the flame is blown-off across at least a part of an operating map of the heat engine. The heat engine may also include a main combustor 16.

The application discloses a wiring method of a diamond wire saw, which comprises the following steps: determining a cutting tension N and a wire diameter D of a diamond wire T according to parameters of a main roller; selecting a coarse-diameter diamond wire T1 according to the wire diameter D of the diamond wire T and fixing the coarse-diameter diamond wire T1 on a main shaft of a take-up wheel; fixing a wire end of the coarse-diameter diamond wire T1 on a rear end of the main roller; starting the main roller to run the wire according to a wire running tension, forming a first local dense wire net; removing the diamond wire that does not fall into a wire groove of the main roller to form a second local dense wire net and fixing the second local dense wire net; continuing to start the main roller to rotate, forming a large-range dense wire net, and pulling out the wire end of the coarse-diameter diamond wire T1 and fixing the wire end of the coarse-diameter diamond wire T1 on a main shaft of a pay-off wheel; after a heat engine is completed, connecting the wire end of the diamond wire T with the wire end of the coarse-diameter diamond wire T1 at a pay-off end, starting the main roller to rotate, running the diamond wire T to the take-up wheel at the cutting tension N, fixing the diamond wire T on the main shaft of the take-up wheel, starting the heat engine, and completing wiring. The application improves the production efficiency and quality of silicon wafers.

The present invention relates to a method for determining whether or not there is a fuel leak in a pressurized fuel system (1) of a vehicle equipped with a heat engine (2), comprising the step of measuring the pressure value in the system (1) at predetermined different points in time within a certain period of time after the vehicle's heat engine (2) has been stopped. This method, - A step of determining the two time points in time where the pressure values ​​are furthest apart from each other, - A step in which, if the absolute value of the difference between these two pressure values ​​is less than or equal to a predetermined pressure difference threshold, the conclusion is drawn that there is a fuel leak in system (1), - A step (230) to determine whether there are two time points in each period where the temperature difference exceeds a predetermined temperature difference threshold, and where the pressure values ​​at these two time points are below a predetermined pressure threshold and exceed the opposite value of this pressure threshold, - If it is determined that these two points in time exist, step (240) to conclude that there is a fuel leak in system (1) and This includes methods.

The application provides a device for testing a rotating part in a high-temperature environment, comprising: a test section for providing a simulated high-temperature environment for the rotating part, and provided with a first through hole and a second through hole; a first tension assembly for pulling an end of the rotating part extending out of the first through hole; a second tension assembly for pulling an end of the rotating part extending out of the second through hole; a first sleeve connected outside the first through hole and sleeved outside the first tension assembly, and provided with at least one first air inlet channel; a second sleeve connected outside the second through hole and sleeved outside the second tension assembly, and provided with at least one second air inlet channel; and an air pressure source connected to the at least one first air inlet channel and / or the at least one second air inlet channel and providing an air pressure greater than or equal to the environmental pressure in the test section. The application can accurately simulate the thermal-mechanical coupling loading environment in which the rotating part is in actual work, and effectively improve the reliability and accuracy of the test results.

This application discloses a method and system for controlling range extender starting and power generation in plateau environments. The method includes: collecting engine coolant temperature and altitude values, setting the engine starting torque and drag time; after the drag time expires, determining the engine's autonomous idle start; if the idle is determined to be successful, entering engine warm-up mode; otherwise, starting and dragging are performed again; in the warm-up state, inputting the engine coolant temperature sample value, and outputting the engine operating speed value and generator output power value according to a preset temperature-speed-power three-dimensional table; after the warm-up ends, when entering the power generation phase, performing closed-loop power output and power generation control according to the power command issued by the vehicle. This application can achieve smooth engine starting and stable power generation in plateau environments.

A method for controlling a thermal and electrical power plant for setting in motion at least one rotary member of a rotorcraft, the power plant comprising at least one heat engine and an electrical system provided with at least one electric machine. The method comprises: selecting, with a selector, an operating mode chosen from several operating modes; determining a density altitude and comparing, with a controller, the current density altitude and a threshold density altitude; and controlling, with the controller, the at least one electric machine depending on at least the chosen operating mode as well as the comparison and a necessary power to be supplied to the power transmission system.

A heat engine in which heat is transferred from the fluid between the output of the generating turbine and the input of the condenser to the fluid between the output of the condenser and the input of

An electric propulsion system for an aircraft, comprising: - an electrical power source (1) including a synchronous generator (11) driven by a heat engine (12), - a first synchronous electric motor (3) connected to an output of the synchronous generator by an alternating current electrical circuit (2), - a rotating propulsion unit (7), characterized in that it comprises: - a direct current electrical circuit (4) comprising, from an input connected to the alternating current electrical circuit: a first alternating / direct current converter (41), a direct current electrical link (42) and a second direct / alternating converter (43), - a second electric motor (5) connected to an output of the direct / alternating converter, - a differential gear train (6) including a first input shaft (61) connected to the first synchronous electric motor,a second input shaft (62) connected to the second electric motor and an output shaft (63) connected to the rotating propulsion unit. Figure for the abbreviation: Figure 1,

The present invention relates to a tool for precision machining, for example for grinding valve seats of a heat engine. The tool according to the invention comprises a housing 2, a sleeve 3 provided with a spherical orientation nut 3a, mounted inside the housing, a one-piece machining shaft 6, mounted freely in rotation and translation within the sleeve, and a means for adjusting the height of the shaft 6, comprising a means for rotationally locking said shaft to a sleeve 17 movable in translation relative to the sleeve.

The application discloses a starting device for a marine methanol engine, which comprises a compressed air control unit, a compressed air starting unit, a supplementary combustion unit, a rotating speed signal sensor and a plurality of Hall sensors. The compressed air control unit comprises a pressure reducing valve, a first one-way valve and a first electromagnetic reversing valve. The compressed air starting unit comprises a first electromagnetic on-off valve, a second electromagnetic reversing valve, a first pneumatic reversing valve, a second one-way valve, a second pneumatic reversing valve and a silencer. The supplementary combustion unit comprises a second electromagnetic on-off valve, a common rail pipe, a supplementary combustion gas injection valve, a third one-way valve and a third electromagnetic on-off valve. The starting device can quickly realize the cold state starting and the hot state starting of the marine methanol engine by using a small number of valve combinations, has high automation degree and good integration degree, and conveniently and efficiently solves the difficult starting problem of the marine methanol fuel engine.

There is provided a heat engine 10 comprising a combustor 120 and a controller 290. The combustor 120 includes a fuel injection port 128 and a pilot 130. The controller 290 is configured to mitigate thermoacoustic instabilities in a gas flow A, B within the heat engine 10 by selectively energising 320 the pilot 130 to ignite fuel discharged from the fuel injection port 128. There is also provided a method 300 of mitigating thermoacoustic instabilities in a gas flow A, B within a heat engine 10 comprising a combustor 120 including a fuel injection port 128 and a pilot 130. The method 300 comprises selectively energising 320 the pilot 130 to ignite fuel discharged by the fuel injection port 128.