Disclosed is a BOG reliquefaction system. The BOG reliquefaction system includes: a compressor compressing BOG; a heat exchanger cooling the BOG compressed by the compressor through heat exchange using BOG discharged from a storage tank as a refrigerant; a bypass line through which the BOG is supplied to the compressor after bypassing the heat exchanger; a second valve disposed on a second supply line through which the BOG used as the refrigerant in the heat exchanger is supplied to the compressor, the second valve regulating a flow rate of fluid and opening/closing of the second supply line; and a pressure reducer disposed downstream of the heat exchanger and reducing a pressure of fluid cooled by the heat exchanger, wherein the compressor includes at least one oil-lubrication type cylinder and the bypass line is joined to the second supply line downstream of the second valve.

A housing defines a gaseous fuel inlet and a gaseous fuel outlet. A rotor defines an internal flow passage therethrough that rotates with the rotor to, alternately, allow gaseous fuel flow, or to block gaseous fuel flow, between the inlet and the outlet, based on a position of the rotor. A seal is biased to abut an exterior surface of the rotor. The seal is between the rotor and the outlet. An actuator is rotably coupled to the rotor. The driver is configured to rotate the rotor. A controller is in communication with the driver and is configured to control the driver to rotate at a rate based on an engine speed of the engine.

A pilot actuated valve assembly includes a valve body having an inlet and an outlet, and includes a main valve, a pilot valve, and a pilot cavity which is at a pilot cavity pressure. A tube houses parts of the pilot valve, and a sleeve engages a portion of the tube, with both being secured to the body by a valve bonnet. The main and pilot valves are coaxial. A solenoid actuator or other suitable actuator is operatively coupled to a shaft of the pilot valve and shifts the pilot valve between the positions. Consequently, the main valve shifts between the closed and open positions in response to shifting of the pilot valve between the closed and open positions.

Systems and methods for supplying primary fuel and secondary fuel to an internal combustion engine may include supplying a first amount of the primary fuel and a second amount of the secondary fuel to the internal combustion engine. The system may include a first manifold to provide primary fuel to the internal combustion engine, and a primary valve associated with the first manifold to provide fluid flow between a primary fuel source and the internal combustion engine. A second manifold may provide secondary fuel to the internal combustion engine, and a fuel pump and/or a secondary valve may provide fluid flow between a secondary fuel source and the internal combustion engine. A controller may determine a total power load, the first amount of primary fuel, and the second amount of secondary fuel to supply to the internal combustion engine to meet the total power load.

Disclosed herein are a fuel supply system for ships and a fuel supply method using the same. The fuel supply method includes: 1) supplying an excess amount of liquefied gas as fuel to an incompressible fluid-fueled engine (E); 2) cooling unconsumed fuel discharged from the engine (E) through heat exchange with liquefied gas discharged from a storage tank (T); 3) returning the unconsumed fuel discharged from the engine (E) and having been cooled through heat exchange in step 2) to the storage tank (T); and 4) supplying the liquefied gas discharged from the storage tank (T) and having been used as refrigerant for heat exchange in step 2) to the engine (E). The fuel supply method can prevent cavitation in the engine (E) by supplying the excess amount of liquefied gas sufficient to accommodate variation in load of the engine (E) as fuel to the engine (E).

A gas fuel supply system for supplying the gas fuel via an opening of an intake supply pipe that is connected to a combustion chamber in an engine operable in each of a gas fuel combustion mode and an oil fuel combustion mode includes: the gas fuel supply valve for regulating an amount of the gas fuel, the gas fuel supply valve having plural gas supply holes, from which the gas fuel is fed in a direction toward the opening when the valve is opened; and an opening regulation valve provided between the gas fuel supply valve and the opening and having an opening hole, an opening area of which can be regulated. The gas fuel supply system is configured that extended axes of all the gas supply holes pass through the fully opened opening hole.

Systems and methods for supplying primary fuel and secondary fuel to an internal combustion engine may include supplying a first amount of the primary fuel and a second amount of the secondary fuel to the internal combustion engine. The system may include a first manifold to provide primary fuel to the internal combustion engine, and a primary valve associated with the first manifold to provide fluid flow between a primary fuel source and the internal combustion engine. A second manifold may provide secondary fuel to the internal combustion engine, and a fuel pump and/or a secondary valve may provide fluid flow between a secondary fuel source and the internal combustion engine. A controller may determine a total power load, the first amount of primary fuel, and the second amount of secondary fuel to supply to the internal combustion engine to meet the total power load.

Various methods and systems are provided for an intake manifold for an engine. In one example, an insert comprises an annular body having a top surface, bottom surface, inner surface, and outer surface. The insert further comprises a first groove for coupling an intake air port of an intake manifold to a cylinder head, a second groove for circulating gaseous fuel received from a gas runner of the intake manifold, and one or more openings to fluidically couple the second groove to an interior of the intake air port. The insert is configured to mix gaseous fuel and intake air at a coupling location between the intake manifold and the cylinder head.

In a gas engine provided with a gas supply pipe (35) branching into a supercharger-side gas supply pipe (33) and a cylinder-side gas supply pipe (37), a supercharger-side gas adjusting valve (43) and a cylinder-side gas adjusting valve (45) for controlling flow rates of passages, when the gas concentration of the fuel gas changes, the cylinder-side gas adjusting valve is controlled first to keep the output of the gas engine constant and then the supercharger-side gas adjusting valve is controlled to achieve the fuel gas flow rate Q1 based on the constant flow ratio by means of a gas supply controller (63), while maintaining the flow rate ratio Q1/Q2 at a constant value where Q1 is a fuel gas flow rate in the supercharger-side gas supply pipe and Q2 is a fuel gas flow rate in the cylinder-side gas supply pipe.

An internal combustion engine with at least one combustion chamber, at least one fuel delivery line for the delivery of fuel to at least one combustion chamber, and at least one differential pressure control valve for controlling the pressure in the at least one fuel delivery line. The at least one differential pressure control valve is configured to perform a valve opening or valve closing movement based on a pressure difference between the at least one fuel delivery line and a reference volume having a reference pressure. The internal combustion engine further includes at least one pressure relief valve, separate from the at least one differential pressure control valve, and configured to open to cause a pressure relief in the reference volume and a decrease in the reference pressure if a drop occurs in the power to be performed by the internal combustion engine.