The present disclosure relates to a method for controlling pressure of an engine, including a controller structured to implement the method and an engine system including the controller. More specifically, the present disclosure relates to a method based on a mass balance analysis of a fuel system to determine how much mass needs to be pumped to maintain or achieve a certain pressure for the engine. In some embodiments, the method analyzes how much mass can be pumped by each pumping event based on current engine conditions. The analysis is performed over the smallest repeatable pump events and cylinder events cycle, or “subcycle,” based on the number of pump events and cylinder events for a given engine configuration.

The present invention relates to a method for operating an internal combustion engine provided as a medium-speed gas engine or dual fuel engine in a gas fuel mode. The method comprises the step of directly injecting a gas fuel into a combustion chamber of the engine at a maximum injection pressure that is lower than a compression-end pressure of the engine.

A port fuel injection system includes a fuel pump configured to produce a flow of pressurized liquid fuel at a pressure between 10 and 50 bar. A fuel rail is connected to receive the flow of pressurized liquid fuel from the fuel pump, the fuel rail. A plurality of fuel injectors, including one fuel injector positioned in the intake port of each engine cylinder upstream of the intake valve for the engine cylinder are connected to receive pressurized fuel from the fuel rail. An engine control unit (ECU) receives signals from sensors on the internal combustion engine and is programmed to actuate the fuel injectors to deliver fuel to each engine cylinder over a full range of engine operating conditions. A port fuel injection system with high pressure and fast acting fuel injectors improves fuel delivery and performance over the full range of engine operating conditions.

Various methods and systems are provided for health assessments of a fuel system. In one example, a fuel system includes a high-pressure fuel pump operable to increase fuel pressure from a first pressure to a second pressure, a common fuel rail fluidly coupling the high-pressure fuel pump to a plurality of fuel injectors each of which is operable to inject fuel to individual cylinders of an engine, a pressure sensor operable to detect a pressure of fuel at the common fuel rail, and a controller operable to diagnose a condition of the high-pressure fuel pump based on output from the pressure sensor.

In an internal combustion engine, combustion stability is improved while exhaust gas emission is suppressed. For this purpose, a control device (1) for controlling an injector (103) is configured to include a control unit (21) that controls the injector (103) to perform a first fuel injection (1001) for injecting fuel at a first fuel pressure from the injector (103) in an intake stroke (S1) in one combustion cycle of an internal combustion engine (100) and a second fuel injection (1002) for injecting fuel at a second fuel pressure higher than the first fuel pressure from the injector (103) after the first fuel injection (1001) in the same one combustion cycle in the intake stroke (S1).

A fuel pressure estimation system estimates a fuel pressure variable on a fuel pressure in a supply pipe for an engine apparatus including an engine having a fuel injection valve, and a fuel supply device having a fuel pump that supplies the fuel in a fuel tank to the supply pipe, and includes a storage device and an execution device. The storage device stores a first mapping that receives, as an input, first input variables including a pump variable, a consumption flow rate variable on a consumption flow rate of the fuel, and a property variable on a property of the fuel, and outputs the fuel pressure variable. The execution device acquires the first input variables and estimates the fuel pressure variable by applying the first input variables to the first mapping.

A fuel type estimation system configured to estimate a type variable related to a type of fuel in an engine system including an engine and a fuel supply apparatus includes a storage device and an execution device. The storage device is configured to store a mapping that uses, as inputs, input variables including an engine variable related to a condition of the engine and outputs the type variable. The execution device is configured to acquire the input variables, and estimate the type variable by applying the acquired input variables to the mapping.

A control device is included in a fuel injection system. The fuel injection system includes a low pressure pump, a high pressure pump, an accumulator, a fuel injection valve, a relief valve, and a return pipe. The high pressure pump increases a pressure of a fuel discharged from the low pressure pump and discharges high pressure fuel. The accumulator stores the high pressure fuel discharged from the high pressure pump. The relief valve is provided in a high pressure portion provided downstream from the high pressure pump and opens when a high pressure abnormality occurs in the high pressure portion. The return pipe returns the high pressure fuel in the high pressure portion to a low pressure portion provided downstream from the low pressure pump by the relief valve opening.

The fuel filling system of a fuel pump reservoir includes: a reservoir mounted in a fuel tank; a fuel pump mounted in the reservoir and configured to deliver the fuel in the reservoir to an engine and to discharge a portion of the fuel to a fuel branch line; a relief valve disposed on a fuel supply line and configured to release pressure applied to the fuel supply line; a first jet pump configured to fill the reservoir with the fuel using fuel jet flow from the fuel branch line; a second jet pump configured to fill the reservoir with the fuel using fuel jet flow from a fuel return line; and a fuel pump control module (FPCM) configured to control operation of the second jet pump based on a driving mode of a vehicle.

A method is disclosed of controlling operation of a fuel injector in response to measuring a quantity of fuel injected by the fuel injector from a fuel accumulator to an engine cylinder during operation of a fuel pump that delivers fuel to the accumulator, comprising: determining an average pressure of the fuel accumulator during a first time period before a fuel injection event; predicting a mass of fuel delivered to the fuel accumulator during a pumping event (Q.sub.pump); determining an average pressure of the fuel accumulator during a second time period after the fuel injection event; estimating a leakage of fuel; computing the injected fuel quantity by adding the average pressure during the first time period to Q.sub.pump, and subtracting the average pressure during the second time period and the leakage; and using the computed injected, fuel quantity to control operation of the fuel injector.