Abstract: An intelligent pressure management system that controls the pressure inside a cryogenic tank between variable target vapor pressure values and/or ranges that are set as a function of system operating conditions, by actuating one or more actively controllable valves, based on a signal received from a pressure sensor that measures the pressure inside the pressurized tank. The variable target vapor pressure values and/or ranges are determined as a function of system operating conditions including the vapor volume in the storage space and a fluid flow demanded by the use device. The target vapor pressure can also be adjusted based on a geographical location, predictive system operation mode, a learned operator use pattern and/or a learned system use pattern.

Abstract: A multi-vessel fluid storage and delivery system is disclosed which is particularly useful in systems having internal combustion engines which use gaseous fuels. The system can deliver gaseous fluids at higher flow rates than that which can be reliably achieved by vapor pressure building circuits alone, and that keeps pressure inside the storage vessel lower so that it reduces fueling time and allows for quick starts thereafter. The system is designed to store gaseous fluid in liquefied form in a plurality of storage vessels including a primary storage vessel fluidly connected to a pump apparatus and one or more server vessels which together with a control system efficiently stores a liquefied gaseous fluid and quickly delivers the fluid as a gas to an end user even when high flow rates are required.

Abstract: A pressure regulating module for regulating the pressure of a first fluid using a reference pressure of a second fluid. A pressure transfer assembly including a piston slidably disposed within a cylinder bore between a control fluid chamber and a reference fluid chamber is dimensioned to provide a predefined radial clearance between at least a portion of the outer side wall and the inner circumferential surface of the housing along a predefined axial length of the main body. The predefined radial clearance and predefined axial length are dimensioned to control the flow rate and amount of fluid along one or more fluid communication passages formed between at least a portion of the piston and the housing inner circumferential surface from one or more high pressure fluid zones to a lower pressure fluid zone which can include a leak and/or weep orifice directing fluid to a drain and/or vent circuit.

Abstract: A multi-vessel fluid storage and delivery system is disclosed which is particularly useful in systems having internal combustion engines which use gaseous fuels. The system can deliver gaseous fluids at higher flow rates than that which can be reliably achieved by vapor pressure building circuits alone, and that keeps pressure inside the storage vessel lower so that it reduces fueling time and allows for quick starts thereafter. The system is designed to store gaseous fluid in liquefied form in a plurality of storage vessels including a primary storage vessel fluidly connected to a pump apparatus and one or more server vessels which together with a control system efficiently stores a liquefied gaseous fluid and quickly delivers the fluid as a gas to an end user even when high flow rates are required.

Abstract: Starting a gaseous fuelled engine employing a pilot fuel at cold temperatures is challenging due to reduced ignitability and combustion efficiency of the fuel(s), and the increased viscosity of engine oil. A technique for starting a compression ignition, gaseous fuelled internal combustion engine employing a pilot fuel comprises determining one of a normal start condition and a cold start condition; during the normal start condition, introducing the pilot fuel into a combustion chamber of the internal combustion engine when the pilot fuel pressure rises above a first pressure; during the cold start condition, introducing the pilot fuel into the combustion chamber when the pilot fuel pressure rises above a second pressure that is higher than the first pressure; and selectively introducing the gaseous fuel into the combustion chamber.

Abstract: A piston arrangement comprises a circumferential piston groove that can accommodate a seal for sealing between the piston and the cylinder bore when the piston moves in a reciprocal movement. The piston arrangement comprises a first fluid flow passage, defined at least in part by the piston body that fluidly connects the forward side of the cylinder bore with a space within the piston groove underneath the seal and a second fluid flow passage, defined in part by the piston body, which fluidly connects the rear side of the cylinder bore with the space within the piston groove underneath the seal. The two fluid flow passages allow a controlled fluid flow around the piston seal and comprise a channel provided in a lateral wall of the piston groove or an orifice provided in the piston body.

Abstract: Premixed engines have ignition issues when engine speed and load are below a predetermined range. An ignition apparatus for igniting a premixed charge in a gaseous-fueled internal combustion engine comprises an ignition device associated with a combustion chamber of the internal combustion engine. There is at least one of a dilutant injector for introducing a diluting agent that forms a stratified charge around the ignition device and an enrichment injector for introducing gaseous fuel that forms a stratified charge around the ignition device.

Abstract: In metal-on-metal sealing structures, the sealing criteria employed for high pressure liquid fuel does not work when sealing gaseous fuels. A technique for sealing a gaseous fuel between gaseous fuel conduits in an internal combustion engine includes forming a contact band between two surfaces of a sealing structure between a first conduit and a second conduit. A width of the contact band is at least equal to the larger of a minimum contact pressure width where contact pressure is at least equal to a predetermined minimum contact pressure; and a minimum yield zone width where at least one of the two surfaces have plastically deformed.

Abstract: A fuel injector for an internal combustion engine is disclosed. The fuel injector is particularly suitable for use as a dual fuel injector, and comprises a generally tubular outer valve needle, an inner valve needle slidably received in the outer valve needle, and a nozzle body assembly comprising a tip part and a needle guide part. The tip part defines a seating region for the outer valve needle, and the needle guide part comprises a guide bore for slidably receiving the outer valve needle. In one embodiment, a lower bore region of the needle guide part defines a cavity around the outer valve needle which houses a biasing spring for the outer valve needle and a fuel. A collar for seating the biasing spring can be dimensioned to allow free flow of the fuel from the cavity into an annular accumulator volume defined between the outer valve needle and the bore of the tip part.

Abstract: A multi-fuel rail apparatus for an internal combustion engine communicates fuel from 10 a first fuel source and a second fuel source to a plurality of fuel injectors. Each fuel injector receives fuel from the multi-fuel rail apparatus through a branch connection for each fuel. The multi fuel rail apparatus has a first elongate member including a first longitudinal bore spaced apart from a second longitudinal bore and first and second fuel inlets for fluidly communicating first and second fuels into the first and 15 second longitudinal bores respectively. There is a branch connecting structure for each fuel injector along the first elongate member for fluidly connecting the first and second longitudinal bores with respective branch connections from respective fuel injectors.

Abstract: Venting of gaseous fuel during operation and after shutdown of an internal combustion engine increases emissions. A vent handling apparatus for a gaseous fuel system of an internal combustion engine comprises an accumulator for storing gaseous fuel; a first valve selectively enabling fluid communication between the accumulator and one of a gaseous fuel communication passage and a gaseous fuel storage vessel, the gaseous fuel communication passage delivering gaseous fuel to the internal combustion engine for combustion; and an apparatus for selectively returning the gaseous fuel from the accumulator to the internal combustion engine for combustion.

Abstract: Gaseous fuel downstream of a heat exchanger can be too cold for fuel system components when the temperature of engine coolant employed as a working fluid in the heat exchanger is too low to elevate gaseous fuel temperature, and it is possible for the engine coolant to freeze. A method of operating a cryogenic pump for controlling discharge temperature of a heat exchanger that vaporizes a process fluid received from the cryogenic pump with heat from a working fluid, where the cryogenic pump includes a piston reciprocatable in a cylinder between a proximate cylinder head and a distal cylinder head, includes monitoring at least one of process fluid temperature and working fluid temperature; retracting the piston during an intake stroke from the proximate cylinder head to the distal cylinder head; and extending the piston in a plurality of incremental discharge strokes until the piston travels from the distal cylinder head back to the proximate cylinder head.

Abstract: A fluid storage and pressurizing assembly includes a storage receptacle and a pump assembly. The storage receptacle includes an inner vessel defining a cryogen space for storing a fluid at a storage pressure and a cryogenic temperature, an outer vessel surrounding the inner vessel, and an insulated space between the inner vessel and the outer vessel, and a pump assembly. The pump assembly includes a pump having an inlet disposed within the cryogen space for receiving a quantity of the fluid from the cryogen space, and an outlet for delivering the fluid therefrom, and a pump drive unit for driving the pump, the pump drive unit being at least partially disposed within a space defined by the storage receptacle.

Abstract: It is a challenge to reduce unburned hydrocarbon emissions for gaseous fuelled engines, especially at low engine load conditions, to meet demanding emission regulation targets. A method for reducing unburned hydrocarbon emissions in a lean-burn internal combustion engine that is fuelled with a gaseous fuel comprises adjusting the timing for closing of an intake valve as a function of engine operating conditions by one of advancing timing for closing of the intake valve and closing the intake valve earlier during an intake stroke; and retarding timing for closing of the intake valve and closing the intake valve later during a compression stroke. The volumetric efficiency of the internal combustion engine is reduced and unburned hydrocarbon emissions are maintained below a predetermined level.

Abstract: An improved body defining a restricted fluid flow passage in a fuel supply system for delivering a gaseous fuel to an internal combustion engine. The body is formed for installation between and fluidly connecting a gaseous fuel supply conduit and a gaseous fuel flow passage that defines a predetermined volume between the restricted fluid flow passage and a nozzle chamber of a fuel injector from which the gaseous fuel is injected into the internal combustion engine. The restricted fluid flow passage has the smallest effective flow area between the gaseous fuel supply conduit and the nozzle chamber. The restricted fluid flow passage is located a predetermined distance from an injection valve seal within the fuel injector. The predetermined distance is calculated as a function of the speed of sound in the gaseous fuel and an opened time of the fuel injector.

Abstract: A method and apparatus for in situ operating an internal combustion engine comprising determining at least one combustion characteristic for a combustion chamber of the internal combustion engine, comprising an actual heat release signal for the combustion chamber; and inputting the actual heat release signal into a diagnostic logic tree for diagnosing changes in combustion characteristics due to at least one of: a malfunctioning fuel injector, a start of combustion timing error; and a change in fuel quality; and performing a mitigation technique to compensate for the changes in combustion characteristics.

Abstract: A fuel injector for an internal combustion engine is disclosed. The fuel injector is installable in a cylinder head bore of a cylinder head of the engine and has a body region arranged to be received within the cylinder head bore, and a head region arranged to extend outside the cylinder head bore to protrude from the cylinder head when the injector is installed in the cylinder head bore. The injector includes a first valve needle arranged to control the injection of a gaseous fuel from a first outlet, a second valve needle arranged to control the injection of a liquid fuel from a second outlet, a gaseous fuel inlet for admitting the gaseous fuel to the injector, and a liquid fuel inlet port for admitting the liquid fuel to the injector. The gaseous fuel inlet is disposed in the body region of the injector, and the liquid fuel inlet port is disposed in the head region of the injector. The injector can also include an internal accumulator volume so that an external fuel rail is not necessary.

Abstract: Draining a cryogenic storage vessel to remove a pump is timing consuming, expensive and can result in increased greenhouse gas emissions. A cryogenic storage vessel comprises an inner vessel defining a cryogen space and an outer vessel spaced apart from and surrounding the inner vessel, defining a thermally insulating space between the inner and outer vessels. A receptacle comprises an outer sleeve and an inner sleeve, and defines passages for delivery of liquefied gas from the cryogen space to outside the cryogenic storage vessel. The outer sleeve intersects opposite sides of the inner vessel, with the opposite ends of the outer sleeve defining an interior space in fluid communication with the thermally insulating space that is sealed from the cryogen space.

Abstract: A piston seal for a reciprocating piston is disclosed having the shape of split ring comprising a first end segment and a second end segment overlapping along a split surface that extends from the inner circumferential surface to the outer circumferential surface of the seal and is transverse to the direction in which the 5 piston moves when reciprocating in a cylinder bore. The split surface is spaced further from the leading lateral surface of the seal that faces a compression chamber associated with the piston than it is spaced from said trailing lateral surface of the seal that is opposite to the leading lateral surface.

Abstract: Diesel-cycle engines are known to have greater power, torque and efficiency compared to Otto-cycle engines of like displacement. When the fuel is a gaseous fuel, such as natural gas, a pilot fuel (such as diesel) is normally required to assist with ignition in a gaseous fuelled Diesel-cycle engine. It would be advantageous to reduce the power, torque and efficiency gap between a Diesel-cycle engine and a gaseous fuelled Otto-cycle engine. A combustion apparatus for a gaseous fuelled internal combustion engine comprises a combustion chamber defined by a cylinder bore, a cylinder head and a piston reciprocating within the cylinder bore. A diameter of the cylinder bore is at least 90 mm and a ratio between the diameter and a stroke length of the piston is at most 0.95.