A control device includes first and second level ratio calculators and an adjuster. The first level ratio calculator calculates a first level ratio of an amount of a first fuel stored in a first tank to a full tank capacity of the first tank. The second level ratio calculator calculates a second level ratio of an amount of a second fuel stored in a second tank to a full tank capacity of the second tank. An octane number of the second fuel is higher than an octane number of the first fuel. The adjuster adjusts a first fuel ratio of the first fuel in a supplied fuel which is supplied to an internal combustion engine and a second fuel ratio of the second fuel in the supplied fuel such that a deviation ratio of the first level ratio and the second level ratio is within a predetermined range.

A method for estimating a specific gravity of a gaseous fuel is described. The gaseous fuel may power an engine and the engine may include a cylinder, a gas valve configured to supply an intake port of the cylinder with the gaseous fuel, a gas rail configured to deliver the gaseous fuel to the gas valve, and a microprocessor adapted to perform the method. The method may comprise establishing a pressure wave in the gas rail by opening and closing the gas valve, wherein the pressure wave travels at the speed of sound in the gaseous fuel. The method may further comprise determining a frequency of the pressure wave in the gas rail, and estimating the specific gravity of the gaseous fuel based on the frequency of the pressure wave.

In a control system for an internal combustion engine that can use a plurality of kinds of fuel including compressed natural gas, the invention prohibits a changeover from CNG to another fuel from being made in a period from a time when CNG is used for the first time after the start of the internal combustion engine to a time when it is determined that properties of CNG do not need to be learned, or a period from the time when CNG is used for the first time after the start of the internal combustion engine to a time when a processing of learning the properties of CNG ends.

Systems, methods and apparatus for controlling operation of dual fuel engines are disclosed that regulate the fuelling amounts provided by a first fuel and a second fuel during operation of the engine. The first fuel can be a liquid fuel and the second fuel can be a gaseous fuel. The fuelling amounts are controlled to improve operational outcomes of the duel fuel engine.

A system for remotely monitoring and controlling operation of a hydro-diesel engine, having: (a) a diesel engine assembly; (b) a hydro-diesel assembly connected to the diesel engine assembly; (c) a remote control system; and (d) a remote computer system in communication with the remote control system, wherein the remote computer system is configured to instruct the remote control system to turn off operation of either: (i) the hydro-diesel assembly while permitting the diesel engine assembly to continue operation while the hydro-diesel assembly is not operating, or (ii) both the hydro-diesel assembly and the diesel engine assembly.

A gas supply system, having a gas regulating station for supplying an engine with gaseous fuel and a double-walled gas line extending from the gas regulating station to the engine, which comprises an inner and an outer pipe, in a gas fuel operating mode the inner pipe is flowed through by the gaseous fuel towards an engine-side end of the double-walled gas line, an inert gas purging line, and a first shut-off valve assigned to the inert gas purging line. In a purging mode inert gas can be fed to the outer pipe at the gas regulating station-side, which inert gas flows through the outer pipe in the direction of the engine-side end of the double-walled gas line, where it passes into the inner pipe and flows via the inner pipe towards the gas regulating station-side end of the double-walled gas line.

A fuel enhancement method and system for supplying the engine with a pressurized fuel mixture comprising a mixture of the liquid fuel and the gaseous component including provisions to maintain the ratio of gas to liquid in the mixture at a predetermined value and maintain the pressure of the fuel mixture applied to the engine at a predetermined value. A system using variable speed drive pumps is disclosed.

In a general aspect, gaseous fuels are blended. In some cases, a fuel blending method includes receiving a flow of a first gaseous fuel in a first flow path of a fuel blending system and receiving a flow of a second gaseous fuel from a second fuel source in a second flow path of the fuel blending system. The heating value of the second gaseous fuel is lower than the heating value of the first gaseous fuel. The first and second gaseous fuels are combined from the first and second flow paths to form a blended gaseous fuel in a third flow path. A heating value of the blended gaseous fuel is measured, and the flow of the first gaseous fuel in the first flow path is adjusted to modify a content of blended gaseous fuel. The blended gaseous fuel can be provided, for example, to an energy conversion system.

An engine system includes: a reformer including a catalyst for decomposing fuel into hydrogen and configured to reform the fuel to generate a reformed gas containing the hydrogen; a temperature detection unit configured to detect a temperature of the reformed gas; a rotation fluctuation detection unit configured to detect an amount of rotation fluctuation of an engine; and a deterioration detection unit configured to detect whether reforming performance of the catalyst of the reformer is deteriorated based on detection values of the temperature detection unit and the rotation fluctuation detection unit, wherein when, in an idling period of the engine, the amount of rotation fluctuation of the engine is equal to or greater than a second threshold in a state where the temperature of the reformed gas is equal to or higher than a first threshold, the deterioration detection unit determines that the reforming performance of the catalyst is deteriorated.

In a general aspect, gaseous fuels are blended. In some cases, a fuel blending method includes receiving a flow of a first gaseous fuel in a first flow path of a fuel blending system and receiving a flow of a second gaseous fuel from a second fuel source in a second flow path of the fuel blending system. The heating value of the second gaseous fuel is lower than the heating value of the first gaseous fuel. The first and second gaseous fuels are combined from the first and second flow paths to form a blended gaseous fuel in a third flow path. A heating value of the blended gaseous fuel is measured, and the flow of the first gaseous fuel in the first flow path is adjusted to modify a content of blended gaseous fuel. The blended gaseous fuel can be provided, for example, to an energy conversion system.