158 results about "Scavenging" patented technology

An ammonia-rich combustion coupled dual-mode prechamber ammonia-fueled engine control system is provided, including an ammonia-fueled engine and an electronic control unit. The ammonia-fueled engine includes a combustion chamber, a dual-mode jet ignition device, and an ammonia injector. The dual-mode jet ignition device includes a prechamber, an air injector, and a fuel injector. When the engine operates, ammonia fuel is firstly injected into the combustion chamber by the ammonia injector to form a rich ammonia-air mixture with air in the combustion chamber. During a compression stroke of the engine, the rich ammonia-air mixture in the combustion chamber is entered into the prechamber through a jet hole. The air injector performs scavenging in the prechamber until a equivalence ratio of prechamber gas mixture is less than 1.0, and then the fuel injector injects fuel into the prechamber forming target mixture. Finally, the target mixture is ignited by the spark plug.

A gas turbine engine includes a fan, a combustor positioned in a core air flowpath that generates combustion gases, a steam system that extracts water from the combustion gases and generates steam, and a gearbox assembly. The steam system includes water storage devices that store the water therein. The water storage devices include a first state in which a level of the water increases or is maintained and a second state in which the level of the water decreases as the water flows through the water storage devices. The gearbox assembly includes a gearbox and a gutter for collecting a gearbox lubricant scavenge flow from the gearbox. The gutter is characterized by a lubricant extraction volume ratio between 0.01 and 0.3, inclusive of the endpoints. The lubricant extraction volume ratio defined by:VGVG⁢B·VGis a gutter volume of the gutter and VGB is a gearbox volume.

The invention provides an opposed piston two-stroke diesel engine vector air inlet-space injection combustion system which comprises an air cylinder sleeve, an air inlet piston, an exhaust piston and a plurality of oil injectors, and the air inlet piston, the exhaust piston and the inner wall of the air cylinder sleeve are matched to form a combustion chamber. A plurality of vector air inlets and exhaust ports are formed in the positions, close to the air inlet piston and the exhaust piston, of the air cylinder sleeve respectively, each vector air inlet is composed of a direct-flow air port and a vortex air port, and the direct-flow air ports and the vortex air ports are arranged at intervals in the circumferential direction; the number of the oil sprayers is two, and the two oil sprayers are arranged on the center face of the air cylinder sleeve in a staggered mode so that the oil sprayers can be arranged in a reverse vortex mode. The problems that an opposed piston two-stroke diesel engine is insufficient in combustion, low in scavenging efficiency and the like are solved, oil and gas in a cylinder can be rapidly and sufficiently mixed through the system, the combustion process is effectively accelerated, combustion in the cylinder is more sufficient, and the combustion efficiency is improved.

A method of lubricating a transmission system including: scavenging, via a lubrication tube of a lubrication system disposed within the transmission system, oil from at least one of a plurality of gears; directing the scavenged oil from the lubrication tube to a plurality of oil conduits extending from the lubrication tube; and translating a shift assembly in a longitudinal direction such that the shift assembly actuates a plurality of poppet valve assemblies disposed in the plurality of oil conduits between a closed position and an open position. The scavenged oil circumventing the plurality of poppet valve assemblies in the open position and the plurality of poppet valve assemblies form a seal with the plurality of oil conduits in the closed position.

The invention belongs to the technical field of piston engines, and particularly relates to a variable-volume crankcase which is integrated with a deformable and automatically-recoverable device, a variable-volume cavity is formed in the crankcase through a deformable or slidable diaphragm, and particularly, an elastic reset element is arranged in the upper surface of the device, so that the variable-volume cavity is formed in the crankcase. It is ensured that the diaphragm can stably and regularly move and reset after deforming or sliding; power for deformation or sliding of the diaphragm comes from periodical extrusion of an engine crank to the diaphragm, by correctly matching a volume change curve of the crankcase with an air distribution phase, the volume of the crankcase is enlarged during air inlet, so that negative pressure in the crankcase is increased, the volume of the crankcase is reduced during scavenging, pressure in the crankcase is increased, and the service life of the crankcase is prolonged. The technical problems of insufficient air intake, low scavenging efficiency, power attenuation and the like of a two-stroke piston engine under the low air pressure condition are solved, and a feasible solution is provided for power improvement of a small aero-engine and power recovery in a high-altitude environment.

The invention relates to the technical field of hydrogen engines, in particular to a hydrogen internal combustion engine and a scavenging control method of the hydrogen internal combustion engine. The hydrogen internal combustion engine comprises an engine cylinder body assembly, a supercharger, an air filtering device, an air supplementing part, an air outlet part and a control device, the air supplementing part comprises a first air supplementing pipeline and at least two second air supplementing pipelines, and an air outlet of the air filtering device is communicated with the first air supplementing pipeline and an air inlet of the supercharger. One end of the first air supply pipeline is communicated with the air filtering device, the other end of the first air supply pipeline is communicated with the crankcase, the cylinder cover is communicated with an air outlet of the supercharger through at least one second air supply pipeline, the crankcase is communicated with the air outlet of the supercharger through at least one second air supply pipeline, and the air outlet part is communicated with the crankcase. The control device is electrically connected with the air supply part and the air outlet part. According to the hydrogen internal combustion engine, through the design of the multiple gas supplementing pipelines, the hydrogen concentration can be effectively reduced, and excessive hydrogen gathering is avoided.

The invention discloses a method and related equipment for determining the air mass flow of an engine cylinder, and the method comprises the steps: introducing a target gas with a preset concentration into an air inlet of the engine cylinder, and determining the first air mass flow of the air inlet; parameter information of target gas on the gas inlet side and the gas outlet side of an engine cylinder is determined; determining the scavenging rate of the engine cylinder according to the parameter information, and determining the scavenging amount of the engine cylinder based on the scavenging rate; and determining a second air mass flow in the engine cylinder according to the scavenging amount and the first air mass flow.

The present disclosure provides a single-flow large turbocharged two-stroke internal combustion engine (100) and a method of operating such an engine (100) configured to supply pressurized scavenge and / or exhaust gas to a pressurized gas consumer (200). The engine includes a plurality of cylinders, an intake system, an exhaust system, one or more turbochargers having a turbine, a fuel system, a bypass system for supplying bypassed pressurized gas to the pressurized gas consumer by taking a controlled amount of scavenge from the intake system to bypass the engine and / or by taking a controlled amount of pressurized exhaust from the exhaust system to bypass the turbine, and a controller configured to adjust the amount of bypassed pressurized gas supplied to the consumer in accordance with sensed scavenge pressure and / or exhaust temperature. The controller is configured to operate the engine in a manner that makes various adjustments to maximize scavenge pressure and / or to maximize scavenge bypass mass flow.

The utility model belongs to the technical field of engines, and discloses a pre-combustion chamber structure and an engine. The pre-combustion chamber structure comprises a pre-combustion chamber body, and the pre-combustion chamber body is provided with a pre-combustion chamber. The pre-combustion chamber body is further provided with an active scavenging channel communicating with the pre-combustion chamber and an active fuel gas channel communicating with the pre-combustion chamber. In the height direction of the pre-combustion chamber, the active fuel gas channel is located below the active scavenging channel. The pre-combustion chamber structure further comprises a control valve block, and the control valve block can selectively connect and disconnect the input end of the active scavenging channel and the scavenging gas source and can selectively connect and disconnect the input end of the active fuel gas channel and the fuel gas source. The starting time for scavenging the pre-combustion chamber and the starting time for introducing fuel gas into the pre-combustion chamber can be conveniently adjusted according to actual working condition requirements; and secondly, the scavenging effect and efficiency of the pre-combustion chamber can be effectively improved, so that the risk that fuel gas in the pre-combustion chamber leaks into a main combustion chamber of the engine is effectively reduced.

The utility model discloses a multipurpose staircase for an exhaust header and an EGB bypass assembly, and relates to the technical field of marine diesel engines, in particular to the multipurpose staircase for the exhaust header and the EGB bypass assembly, which comprises a staircase main frame, the staircase main frame is step-shaped, a lower platform is arranged on a step-shaped platform of the staircase main frame, and an upper platform is arranged on the lower platform. The escalator comprises an escalator main frame, an upper platform is installed at the top of the escalator main frame, detachable handrails are installed at the top of the escalator main frame, connecting lugs are fixedly installed on the handrails, and a chain assembly capable of protecting maintainers on the upper platform is installed between the connecting lugs. According to the multi-purpose escalator for the exhaust header and the EGB bypass assembly, the multiple platforms formed on the escalator main frame can be used for entering a scavenging header manhole cover and operating the EGB bypass assembly correspondingly, the dual-purpose effect of one escalator is achieved, then the multi-purpose escalator is more convenient to use, and personnel can be protected under the action of the chain assembly.

The invention aims at providing a large-load unmanned engine system and a control method thereof.The large-load unmanned engine system comprises an engine body assembly, a power assembly and a fuel assembly, the engine body assembly comprises an engine brake, at least two cylinder bodies and at least two spark plugs, and every two cylinder bodies are arranged on the engine brake in a central symmetry mode; the sparking plugs are arranged at the ends, away from the machine brake, of the cylinder bodies respectively, an air inlet hole is formed in the position, between the two cylinder bodies in the same set, of the machine brake, the machine brake and the cylinder bodies are each provided with a scavenging channel, each cylinder body is provided with an exhaust hole, and the power assembly comprises a crankshaft, at least two pistons and at least two connecting rods. The crankshaft is rotatably arranged in the brake, the pistons are slidably arranged in the cylinders respectively, the connecting rods are rotatably connected with the pistons respectively, the connecting rods are rotatably connected with the crankshaft, the fuel assembly comprises at least one air inlet valve and at least one carburetor, the air inlet valves are arranged on the air inlet holes respectively, and the carburetors are arranged on the air inlet valves respectively.

The invention provides a piston combustion chamber suitable for an opposed-piston two-stroke diesel engine, which is characterized in that the combustion chamber structure is a half-rugby-type structure, two opposed notches are formed in the edges of the two sides of a piston, the middle of the half-rugby-type structure is in a concave bowl shape, and the inner wall surface of the half-rugby-type structure is a smooth surface; the two oppositely-arranged notches are correspondingly formed in the central axis of the combustion chamber, the two oil sprayers are oppositely arranged and located at the two oppositely-arranged notches, each oil sprayer is provided with three oil spraying holes, and the oil beam included angle formed by the three oil spraying holes is smaller than the taper angle formed by connecting lines from the top faces of the oil sprayers to the center of the bottom of the boss. According to the two-stroke diesel engine, the good scavenging performance of an original combustion chamber structure can be guaranteed, oil and gas can be rapidly and fully mixed on the basis that materials of the combustion chamber are not changed, the combustion process is improved, and the combustion efficiency is improved.

The utility model provides an overhead valve guide air inlet type two-stroke engine which solves the problems that waste gas cannot be fully swept away due to the fact that a four-stroke working mode of a traditional overhead valve type engine is improved into a two-stroke working mode, and combustion efficiency and emission performance are poor. According to the technical scheme, the overhead valve guide air inlet type two-stroke engine comprises an engine body set and an air distribution mechanism provided with an overhead valve, an air guide pipe moving along with an air inlet valve rod through a support sleeve is arranged on the air inlet valve rod of the air distribution mechanism, the air guide pipe is close to the head of the air inlet valve, and a front end air outlet is reserved between the front end of the air guide pipe and the head of the air inlet valve. The rear port of the gas-guide tube communicates with the gas inlet channel; an air inlet cam of the air distribution mechanism is provided with an air inlet cam protruding part which pushes the front end of an air guide pipe of an air inlet valve to stretch into an inner cavity of the air cylinder body. By guiding and scavenging the inlet air, the engine can go deep into the cylinder body to purge the combusted waste gas, open the exhaust valve to work and fully sweep the waste gas, so that the scavenging efficiency is greatly improved, and the combustion efficiency and the emission performance are improved.

The disclosure relates to a tank ventilation apparatus for a motor vehicle which has a scavenging line which is arranged between an activated-carbon container and an intake line of the motor vehicle and in which an electrically driven scavenging pump is arranged. Furthermore, an electrically controllable directional control valve is provided in the scavenging line between the activated-carbon container and the electrically driven scavenging pump.

To provide an electric vehicle capable of suppressing deterioration of electricity efficiency. [Solution] An electric vehicle includes an internal combustion engine (10), a first motor-generator (310), and a control device (100). A processing circuit (110) of the control device (100) performs scavenging operation by rotating the internal combustion engine (10) with the first motor-generator (310) after its autonomous operation has been stopped. When an execution condition for the scavenging operation is met, the processing circuit (110) acquires the engine rotation speed at that time as a first rotation speed and sets a second rotation speed as a target value for the engine rotation speed during the scavenging operation. After the autonomous operation of the internal combustion engine (10) is stopped based on the execution condition for the scavenging operation being met, the processing circuit (110) controls the first motor-generator (310) to reduce the engine rotation speed to the second rotation speed while maintaining the engine rotation speed at a value between the first rotation speed and the second rotation speed. The processing circuit (110) starts scavenging operation based on the engine rotation speed being reduced to the second rotation speed through control of the first motor-generator (310).

The application relates to the technical field of ship power control, and discloses a ship power system energy efficiency optimization control system based on multi-sensor fusion, which comprises the following modules: a multi-source data acquisition module, which is used for synchronously collecting hull, shafting and air path parameters; a kinematics mapping calculation module, which is used for calculating a propeller transient immersion index; a phase extraction and mode determination module, which is used for extracting a wave phase and an amplitude output mode signal; a fuel mechanical dynamics feedforward module, which is used for generating an oil injection instruction according to the amplitude and the immersion index derivative; an air thermodynamics cooperative control module, which is used for controlling a valve and starting a scavenging blower according to a phase angle; and a long-term energy efficiency optimization module, which is used for finely adjusting a main rotating speed setting value according to an energy efficiency cost function gradient. The technical scheme of extracting the transient immersion index and the fluctuation amplitude to dynamically adjust the rotating speed control dead zone and superimpose a negative fuel feedforward instruction is adopted, so that the technical effects of suppressing abnormal fluctuation of the main engine rotating speed under high sea conditions and reducing unnecessary fuel consumption are achieved.

The present invention discloses a two-stroke engine system and a control method thereof, comprising a cylinder and an ECU electronic control unit, wherein two exhaust ports are respectively located on opposite side walls of the cylinder wall and are positioned horizontally, a plurality of scavenging ports are arranged on the cylinder wall in a horizontal arrangement relative to the cylinder wall, and the intake direction of the scavenging ports is at an angle of 10°-20° with the tangent direction of the cylinder wall, thereby causing the incoming fresh air to form a swirl flow within the cylinder; two methanol injectors and a high-pressure injector are disposed within the cylinder head, and the nozzles of the methanol injector and the high-pressure injector both extend into the combustion chamber; two diesel injectors are also disposed within the cylinder wall, located between the exhaust ports and the scavenging ports, and their nozzles extend into the combustion chamber; the ECU electronic control unit is configured to control the injection of the methanol injector, the diesel injector, and the high-pressure injector according to the engine load. The present invention controls the injection ratio of the diesel injector and the methanol injector according to the engine operating condition, and controls whether the high-pressure injector participates in enhancing the mixing of the mixture.

The utility model relates to a marine free piston internal combustion engine propulsion power device. Two cylinder units are respectively provided with a combustion chamber and a hydraulic piston; the U-shaped hydraulic pipe is filled with hydraulic oil and is connected with the hydraulic pistons of the two air cylinder units to transmit power. The hydraulic piston is arranged in the propelling hydraulic cylinder body, the propelling hydraulic cylinder body is linked with the hydraulic piston, and water absorption and drainage are achieved through the water inlet pipe and the high-pressure injection pipe; a water inlet valve in the control valve system is connected with a propelling hydraulic cylinder body and used for controlling low-pressure water suction of the propelling hydraulic cylinder body, and the propelling hydraulic cylinder body is connected with a high-pressure spraying pipe through a front high-pressure water spraying water outlet valve and a rear high-pressure water spraying water outlet valve and used for selecting the water spraying direction to achieve advancing or retreating of the ship. The supercharger is connected with the scavenging box. The reciprocating type internal combustion engine is innovated on the basis of a traditional reciprocating type internal combustion engine, the traditional working mode that a propeller is driven through crankshaft transmission is abandoned, and a ship propelling power device is completed in a reciprocating type free piston water spraying propelling mode.

In a method for operating an internal combustion engine (10) with gaseous fuel, compressed air is supplied to a combustion chamber (14) at least temporarily by means of an exhaust gas turbocharger (24). Furthermore, scavenging is active at least temporarily in this method. It is proposed that when scavenging is active, and depending on the result of an evaluation of a parameter that characterizes a target power increase, a measure is implemented to limit exhaust back pressure.

The invention provides a structure suitable for compensating deformation of a scavenging type air cylinder sleeve. The air cylinder sleeve is mounted in an air cylinder sleeve seat hole; the cylinder sleeve is radially provided with one or more oil injector holes; the crankcase is provided with a fuel injector bush mounting hole; the oil injector bushing is arranged in the oil injector bushing mounting hole, the lower end of the oil injector bushing is in threaded connection into the oil injector hole, and a copper pad is arranged between the oil injector bushing and the cylinder sleeve; a gap is formed between the oil injector bush and the oil injector bush mounting hole; the packing washer is combined with the oil sprayer bushing; a second rubber ring is arranged between the lower surface of the packing washer and the crankcase. The fuel injector bushing nut is in threaded connection with the fuel injector bushing; the bottom of the oil sprayer bushing nut is attached to the upper surface of the packing washer. The oil sprayer bushing is provided with a mounting seat hole and is communicated with the cylinder; and a closed combined water cavity is formed among the oil sprayer bushing, the cylinder sleeve and the crankcase. The oil nozzle is effectively prevented from being overheated, so that faults such as carbon deposition of the oil nozzle and high-temperature failure of an oil head are avoided, and the performance and the service life of the oil injector are improved.

The application discloses a double-piston direct-current scavenging type free-piston internal combustion linear generator, which comprises two combustion chambers arranged on the left and right sides of the linear generator, and piston mover assemblies reciprocating in the left and right combustion chambers; the top of the combustion chamber is provided with a controllable electromagnetic exhaust valve, an electronic spark igniter and an oil nozzle; the middle of the combustion chamber is attached with corresponding radiating fins; the bottom of the combustion chamber is connected with a corresponding scavenging chamber; the linear generator is provided with corresponding stator coil windings, linear Hall elements, piston assemblies and permanent magnets attached to the piston assemblies. The double-piston direct-current scavenging type free-piston internal combustion linear generator utilizes the direct-current scavenging technology, improves the scavenging quality of the existing free-piston internal combustion linear generator, changes the structure of the original piston assembly, and avoids the piston from impacting the combustion chamber cylinder cover or misfire caused by the change of external load when the system is running.

The application discloses a kind of short process from copper-molybdenum mixed concentrate high-efficiency recovery molybdenum method, management is simple and convenient, reagent cost is low, separation efficiency is high, strong adaptability, index is stable.Hydraulic cyclone classification overflow is dehydrated and depharmaceutical by thickener and then enters the flotation column to carry out fine selection I operation, fully gives the characteristics of fine particle level high-efficiency recovery of flotation column, uses diesel instead of kerosene as collector, improves the thickness and stability of foam.Hydraulic cyclone classification underflow and flotation column tailings are mixed into fine scavenging, one is to optimize the particle size composition, play the function of coarse particle level carrier, form carrier flotation, strengthen the recovery of fine particle level, two is to give full play to the performance of flotation machine, increase the recovery effect of coarse particle level, also avoid the wear and blockage of coarse particle level to the aeration device in the flotation column.Sweeping concentrate and fine scavenging tailings are combined and ground, through depth dissociation of intergrowth, effectively reduce the content of molybdenum in sweeping tailings, improve the comprehensive recovery rate of molybdenum.

A turbine engine includes a first gearbox lubricated by oil. A first sump located below the first gearbox collects oil. The first purge element pumps oil from the first sump in an operating state and does not pump oil in a fault state. The second gearbox is also lubricated by oil. A second sump located below the second gearbox collects oil. A second purge element pumps oil from the second sump in an operating state and a fault state. A conduit connects the first tank to the second tank to transfer the overflow oil from the first tank to the second tank in a fault condition, the overflow oil combining with the oil in the second tank when the oil in the first tank reaches a threshold level.

This invention belongs to the field of engine technology and discloses an engine control method and an engine. The engine control method includes: determining the limiting crankshaft angle range corresponding to the start of scavenging in the pre-combustion chamber based on a preset injection pressure and a preset injection quantity; determining the conditions for starting scavenging in the pre-combustion chamber based on the temperature and pressure of the main combustion chamber, the preset injection pressure, and the limiting crankshaft angle range; and initiating scavenging in the pre-combustion chamber with the preset injection pressure and preset injection quantity. By employing this engine control method, the scavenging quality and efficiency of scavenging in the pre-combustion chamber can be effectively improved, as can the ignition efficiency and ignition reliability of igniting the combustion gases within the pre-combustion chamber.

The utility model belongs to the technical field of engine pistons, and discloses a transverse flow scavenging outboard engine piston which comprises a piston body and an air cylinder, and the piston body comprises a piston skirt part, a piston head part and a piston convex top. Through cooperation of a piston convex top, a piston pin, a first flow guide angle, a second flow guide angle and other structures, the device has the effects of being high in scavenging efficiency and reducing oil consumption, the piston body moves to the exhaust hole, waste gas in the air cylinder is exhausted from the exhaust hole through the first flow guide angle, then the piston body continues to move downwards, and the effect of reducing oil consumption is achieved. Through the design of the second flow guide angle on the convex top of the piston, waste gas in the air cylinder is guided out through the second flow guide angle, and when the piston body crosses a lower dead center to move upwards, mixed gas is guided through the convex top of the piston, so that the waste gas in the air cylinder is removed more thoroughly, and the effect of few waste gas residues is achieved; and the performance of the engine is improved.

The present invention relates to an injector (1) for injecting a gaseous medium, in particular a gaseous fuel, preferably hydrogen, into a combustion chamber (20) of an internal combustion engine. The injector (1) comprises, inter alia, an axially movable valve closing element (5) for opening and closing at least one opening on a sealing seat (7), an actuator (21) for actuating the valve closing element (5), and a flow-control geometry (10) located downstream of the sealing seat (7).According to the invention, the flow control geometry (10) is designed such that it is formed downstream of the sealing seat (7) in an attachment body (8), wherein the attachment body (8) has a hollow cylindrical section in the area of ​​the sealing seat (7), to which an outflow area (16) with at least one outflow opening (17) having an inner contour (9) is connected, which opens into an end side (25) facing the combustion chamber (20), wherein in the transition from the hollow cylindrical section to the at least one outflow opening (17) the inner contour (9) has a trough-like section (22), from which at least one additional opening (24) is connected with the outer contour of the attachment body (8) in order to improve a scavenging behavior from the outflow opening (17).

To improve startability of an engine regardless of a state of a lock pin in a variable valve train in an engine control device.SOLUTION: An engine control device 30 includes a setting part 31 and a control part 32. When the engine 1 is stopped, the setting unit 31 sets the flag to ON if the oil temperature of the engine oil that drives the variable valve mechanism 10 is equal to or lower than a predetermined temperature, and sets the flag to OFF if the oil temperature exceeds the predetermined temperature. At the start of the engine 1, the control unit 32 performs the normal control when the flag is off, and performs the scavenging control and the normal control when the flag is on. The normal control is a control for starting the engine 1 by cranking while performing both fuel injection and ignition. The scavenging control is control for scavenging the inside of the combustion chamber by cranking without performing both fuel injection and ignition.SELECTED DRAWING: Figure 1

The application discloses a turbocharger and cam phase coordinated control method, device, controller and storage medium. The method part comprises the following steps: when a target cam enters a scavenging mode, a difference between a target intake manifold pressure and an actual intake manifold pressure is obtained; whether a dynamic cam phase coordination function is activated is judged according to the difference between the target intake manifold pressure and the actual intake manifold pressure; a dynamic cam phase coordination control coefficient corresponding to an activation condition of the dynamic cam phase coordination function is obtained; a target phase angle corresponding to the target cam is determined according to the dynamic cam phase coordination control coefficient and an engine operating condition; and the phase of the target cam is adjusted according to the target phase angle.

The invention relates to a divisional application of which the application number is 202510973180. X. The invention discloses a two-stroke engine, and belongs to the technical field of engines. The two-stroke engine comprises a cylinder body and a piston, the cylinder body is provided with an air inlet, an air outlet and a scavenging channel, the hole wall of a combustion chamber is provided with a pair of first scavenging ports, a pair of second scavenging ports and a pair of third scavenging ports, and the air blowing elevation angles of the first scavenging ports, the second scavenging ports and the third scavenging ports are sequentially reduced. And the pressure applying device is used for applying gas pressure deviating from the exhaust port to scavenging gas generated by the scavenging port which is opened later to scavenging gas generated by the scavenging port which is opened first. According to the two-stroke engine, by means of the gradient change of the blowing elevation angles of the three pairs of scavenging ports, the combustible mixed gas is stabilized through scavenging airflow with the smaller elevation angle step by step, the situation that cyclone is formed and mixed with waste gas is prevented, effective separation of the scavenging gas and the combustion waste gas is achieved, the fuel oil utilization rate of the two-stroke engine is increased, tail gas emission is improved, and the service life of the two-stroke engine is prolonged. And the effects of energy conservation and emission reduction are achieved.

Plant and process for converting a gaseous hydrocarbon feed to methanol, optionally to a transportation range fuel such as any of a gasoline product, a jet fuel product, and a diesel product; the plant including a synthesis gas section, a methanol synthesis section, optionally and a transportation range fuel synthesis section. The plant also includes diverting and supplying a purge gas from the methanol synthesis section to a water gas shift (WGS) section, CO2-removal section, and a first hydrogen purification section. In an embodiment, the first hydrogen purification section provides a first H2-rich gas, a second H2-rich gas, and a first hydrogen purification section off-gas. One or more fired heaters are suitably arranged to receive at least a portion of the second H2-rich gas.