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.

Method of preheating and controlling the temperature of fuel injected into a combustion engine to enable a reduction in the amount of fuel injected into engines which may be powered both by pure gasoline and by ethanol or any biofuel mixture, where the engine is located in environments with low temperatures and extremely cold temperatures.

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.

The present invention relates to a pressure coupled control method and system for diffusion combustion of a natural gas engine, the method comprising: S11: detecting an operating condition of a natural gas engine; S12: an electronic control unit calculating a target diesel fuel pressure value flowing into a fuel rail of the natural gas engine according to the operating condition, and detecting an actual diesel fuel pressure value flowing into the fuel rail by means of a diesel pressure sensor in the fuel rail; S13: the electronic control unit calculating a target natural gas pressure value flowing into a gas rail of the natural gas engine according to the actual diesel fuel pressure value, and regulating a natural gas flowing into the gas rail by means of a signal of a gas rail pressure sensor in the gas rail; S14: after the target diesel fuel pressure value and the target natural gas pressure value are established, successively injecting high pressure diesel fuel and a high pressure natural gas into a gas cylinder; S15: detecting in real time a real-time operating condition of the natural gas engine, and promptly regulating the target diesel fuel pressure value and the target natural gas pressure value according to the real-time operating condition. The present invention improves diffusion combustion efficiency by means of the pressure coupled control of diesel fuel and natural gas.

A method of detecting a percentage of ethanol in fuel used by an engine is provided. The method includes obtaining the heater temperature at a first time t.sub.1 at which a slope of the heater temperature as a function of time reaches a predetermined threshold value indicative of fuel boiling; obtaining the heater temperature at a subsequent time t.sub.2 at which the slope of the heater temperature approaches a value of the slope prior to the time t.sub.1 and which is greater than the predetermined threshold value; and determining the percentage of ethanol in the fuel as a function of the first time t.sub.1 and a calculated temperature difference T between the heater temperature at time t.sub.2 and the heater temperature at the first time t.sub.1. A fuel delivery system that detects a percentage of ethanol in fuel by the method, and a flexible fuel vehicle including the fuel delivery system, are also provided.

A method for deposit mitigation in a gaseous fuel injector that introduces a gaseous fuel through a gaseous fuel orifice directly into a combustion chamber of an internal combustion engine includes at least one of a) reducing the ago length of the gaseous fuel orifice by substantially between 10% to 50% of a previous length of a previous gaseous fuel orifice showing deposit accumulation above a predetermined threshold; b) providing the gaseous fuel orifice with an inwardly and substantially linearly tapering profile; c) determining deposit mitigation is needed; and performing at least one of the following deposit mitigation techniques i) increasing gaseous fuel injection pressure wherein deposit accumulation is reduced during fuel injection; and ii) decreasing gaseous fuel temperature wherein a rate of deposit accumulation is reduced; and d) injecting compressed air through the gaseous fuel orifice during shutdown of the internal combustion engine; whereby torque loss in the internal combustion engine due to deposit accumulation in the gaseous fuel orifice is reduced below a predetermined value.

Method of preheating and controlling the temperature of fuel injected into a combustion engine to enable a reduction in the amount of fuel injected into engines which may be powered both by pure gasoline and by ethanol or any biofuel mixture, where the engine is located in environments with low temperatures and extremely cold temperatures.

A vehicle propulsion system includes a first pump having an inlet for receiving fuel from a fuel reservoir and an outlet for providing pressurized fuel to a fuel feed line at a first pressure, a fuel feed line pressure sensor, a second pump having an inlet for receiving fuel from the fuel feed line and an outlet for providing pressurized fuel to an engine fuel rail at a second pressure, the second pressure being higher than the first pressure, a fuel temperature sensor, and a controller controlling the first pump to reduce the pressure of the fuel in the fuel feed line and determining whether the pressure of the fuel in the fuel feed line has reached a vaporization pressure of a component in the fuel.

A generator and off-board fuel delivery system is disclosed. The generator is configured to operate on one or more fuels, including on a gaseous fuel supplied from a pressurized fuel source through a gaseous fuel line. A fuel regulator system is located off board the generator and is configured to regulate the gaseous fuel supplied from the pressurized fuel source in a first stage, with the gaseous fuel regulated down to a reduced pressure in the first stage. A second stage of the fuel regulator system regulates the reduced pressure gaseous fuel, with the reduced pressure gaseous fuel from the first stage regulated down to a desired pressure in the second stage for delivery through the gaseous fuel line to operate the generator.

A fuel system for a prime mover includes a controller including at least one processor to determine a primary pressure value for a primary fuel, determine a secondary pressure value for a secondary fuel, and perform a first switch from the primary fuel to the secondary fuel if the primary pressure value is lesser than a first lower pressure threshold value, the secondary pressure value is greater than a second upper pressure threshold value, an operating speed value of the prime mover is greater than a fuel type initialization speed threshold value for the prime mover, an absolute speed error value is lesser than a steady-state absolute speed error threshold value for the prime mover, an operating load to be applied on the prime mover is greater than a rated load of the secondary fuel, and a fuel switchover timer threshold duration from a previous fuel switching event has elapsed.