Disclosed is a valve needle for a needle valve of a slurry fuel injector valve, the valve needle comprising: a tip for abutting a needle valve seat of the needle valve; a sealing portion for location in a bore of the needle valve; and a fuel chamber portion between the tip and the sealing portion, wherein the fuel chamber portion is for location in a needle fuel chamber of the needle valve; wherein a surface of the sealing portion of the valve needle comprises at least one groove and wherein at least part of the or each groove extends in a direction that is non-perpendicular to an axial direction of the valve needle.

A fuel supply valve for a slurry fuel injector valve comprises a fuel inlet in fluid communication with a slurry fuel reservoir. A fuel outlet is in fluid communication with a nozzle of the fuel injector valve. A pump chamber port is in fluid communication with a pump chamber of the fuel injector valve. A valve gate is moveable between a first position wherein the fuel inlet is in fluid communication along a first slurry fuel flow path with the pump chamber port and a second position wherein the fuel outlet is in fluid communication along a second slurry fuel flow path with the pump chamber port. Wherein the valve gate is arranged to not substantially exert a force opposing a flow on the slurry fuel into the valve chamber when the valve gate moves between the second position and the first position and/or between the first position and the second position.

A fuel circulation system of a diesel type engine configured to use carbonaceous aqueous slurry or emulsion fuels. The diesel type engine includes a fuel injection system which is fluidly connected to the fuel circulation system. The fuel circulation system comprises: at least one fuel feed pump comprising a positive displacement pump located in the fuel circulation system before the fuel injection system, the fuel feed pump configured to supply a controlled amount of carbonaceous aqueous slurry fuel to the fuel injection system; and at least one volumetric flow controller comprising at least one of a second positive displacement pump configured to operate in reverse as a positive displacement pressure let-down device, or a volumetric flow valve operated as a positive displacement pressure let-down device, the volumetric flow controller located in the fuel circulation system after the fuel injection system, the volumetric flow controller providing a controlled regulation of return flow/fuel system pressure from the fuel injection system from zero to maximum flow/pressure.

A sulfur oxide detection system includes an element part which includes a sensor cell and a diffusion regulating layer. The sensor cell includes a solid electrolyte layer, a first electrode arranged, and a second electrode. The sulfur oxide detection system also includes a voltage application circuit configured to apply a voltage to the sensor cell so that a potential of the second electrode becomes higher than a potential of the first electrode, and a current detection circuit configured to detect a current flowing between the first electrode and the second electrode. The sulfur oxide detection system further includes a controller coupled with the voltage application circuit and the current detection circuit, and configured to estimate a sulfur oxide concentration in a gas to which the first electrode is exposed by way of the diffusion layer.

An engine (21) including a main fuel injection valve (79), a pilot fuel injection valve (82), a liquid fuel supply rail pipe (42), and a pilot fuel supply rail pipe (47). The main fuel injection valve (79) supplies liquid fuel from the liquid fuel supply rail pipe (42) to a combustion chamber (110) during combustion in a diffusion combustion system. The pilot fuel injection valve (82) supplies pilot fuel from the pilot fuel supply rail pipe (47) to the combustion chamber (110) in order to ignite gaseous fuel during combustion in a premixed combustion system. The liquid fuel supply rail pipe (42) is disposed at one side of an imaginary vertical plane (P1) including an axis of a crank shaft. The pilot fuel supply rail pipe (47) is disposed at the side of the imaginary vertical plane (P1) at which the liquid fuel supply rail pipe (42) is disposed.

Provided is a fuel composition prepared by adding gas-to-liquid oil and water to light cycle oil to conduct emulsification. The fuel composition is used as a fuel for a diesel engine (12) in a ship (10). The ship (10) includes a fresh water tank (15), an LCO tank (13), and a GTL tank (14) configured to store water, light cycle oil, and gas-to-liquid oil, respectively, and a mixer (16) configured to mix the water, the light cycle oil, and the gas-to-liquid oil fed from the respective tanks to produce the fuel composition.

An engine device (21) including: an intake manifold (67) configured to supply air into a cylinder (77); an exhaust manifold (44) configured to output exhaust gas from the cylinder (77); a gas injector (98) which mixes a gaseous fuel with the air supplied from the intake manifold (67); and a main fuel injection valve (79) configured to inject a liquid fuel into the cylinder (77) for combustion. At the time of switching from a gas mode in which the gaseous fuel is supplied into the cylinder 77 to a diesel mode in which the liquid fuel is supplied into the cylinder (77), a supply-start timing of the liquid fuel is delayed relative to a supply-stop timing of the gaseous fuel.

An engine device, which employs various types of fuels, plural fuel pipes can compactly be disposed without being thermally affected by exhaust gas. In the engine device, a gas fuel pipe that supplies gas fuel to a gas injector, a fuel oil pipe that supplies liquid fuel to a main fuel injection valve are disposed to be divided on both sides of a row of head covers arranged in a line. In addition, in the engine device, an intake manifold that supplies air taken in by a main combustion chamber toward an intake valve extends in parallel to the row of head covers in a cylinder block, and the fuel gas pipe and the intake manifold are arranged on the same side of the row of head covers.

A system for supplying fuel to an engine of a ship. The system includes a high pressure pump pressurizing a liquefied natural gas (LNG) and supplying the pressurized LNG to the engine, a hydraulic motor driving the high pressure pump and a chamber carrying the high pressure pump and the hydraulic motor. The chamber is substantially free of electric sparks.

The temperatures of fuel oils stored in fuel tanks 12a, 12b, 12c are separately detected by temperature sensors 52a, 52b, 52c, respectively. Based on the detection results, a CPU 49 heats a heat resistant fuel oil among the fuel oils using a heat exchanger 54, such that the temperature of an oil mixture generated by mixing the fuel oils satisfies a predetermined temperature condition. After the fuel oils including the heated heat resistant fuel oil are mixed in a blender 13, the CPU 49 detects the viscosity of the generated oil mixture using a viscometer 33. Thereafter, based on the detection result, the CPU 49 controls the mixture ratio or a heating temperature of the heat resistant fuel oil, such that the viscosity of the oil mixture satisfies a predetermined viscosity condition.