A supplemental fuel system includes a supplemental fuel tank, an electronic lock off valve, a temperature sensor, and a controller. The supplemental fuel tank is configured to store a supplemental fuel. The supplemental fuel is configured to supplement a primary fuel used by an engine. The electronic lock off valve is configured to be positioned between the supplemental fuel tank and an air supply system for the engine. The temperature sensor is configured to acquire temperature data regarding a temperature of exhaust gas output by the engine. The controller is configured to control the electronic lock off valve such that the electronic lock off valve is (i) closed in response to the temperature being greater than a temperature threshold and (ii) open or openable in response to the temperature being less than the temperature threshold.

The invention relates to a method for controlling gaseous fuel pressure in an accumulator (12) of a fuel system (10) for a combustion engine (102) of a vehicle (100), wherein the method comprises the steps of: determining a nominal amount of gaseous fuel to be introduced into the accumulator; introducing less gaseous fuel into the accumulator than the determined nominal amount by reducing or closing an inlet valve (24), which inlet valve is adapted to regulate input of gaseous fuel to the accumulator; and while the inlet valve is reduced or closed, performing at least one injection of gaseous fuel coming from the accumulator into at least one combustion chamber (104a-f) of the combustion engine by at least one injector (14a-f) of the fuel system, which at least one injection contributes to combustion in the combustion engine, thereby reducing pressure in the accumulator. The invention also relates to a corresponding fuel system (10).

A gas feed method for a gas engine or dual-fuel engine in which combustion gas (G) is burned with combustion air (L). A gas valve (1) for the feed of combustion gas (G) into the combustion air (L) is arranged upstream of the gas engine or dual-fuel engine. The combustion gas (G) is fed in uncontrolled fashion to the gas valve (1) independently of the operating state of the gas engine or dual-fuel engine. The invention furthermore relates to a gas supply apparatus. A gas valve (1) for the feed of combustion gas (G) into the combustion air (L) is arranged in the gas feed (10) upstream of the gas engine or dual-fuel engine. Control of the gas pressure in a manner dependent on the operating state of the gas engine or dual-fuel engine is not provided upstream of the gas valve (1).

Methods and systems of controlling operation of a dual fuel engine are provided, comprising determining a target exhaust temperature, sensing an actual exhaust temperature, determining an exhaust temperature deviation by comparing the actual exhaust temperature to the target exhaust temperature, comparing the exhaust temperature deviation to a threshold, adjusting at least one of an intake throttle, a wastegate, a compressor bypass valve, an exhaust throttle, a VGT and engine valve timing when the exhaust temperature deviation exceeds the threshold to control charge-flow to the engine, and continuing the adjusting until the exhaust temperature deviation is less than the threshold.

Embodiments of a gaseous or dual fuel electronic pressure regulation system (EPRS) for a multipoint fuel injection engine are described herein. Additionally, embodiments of a method for controlling the EPRS are provided. In particular, the EPRS employs an electronic pressure regulator (EPR) capable of accurately determining and controlling the mass flow of gaseous fuel into a fuel rail so as to avoid pressure droop and over- and under-pressurization of the gas admission valves (GAVs). By using the EPRS described above, mass flow is able to be distributed to the downstream manifold or engine cylinders very accurately, and the GAVs are able to be driven simultaneously in a pressure/pulse duration that is optimal for accurate and repeatable operation.

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.

The invention relates to a method for controlling gaseous fuel pressure in an accumulator (12) of a fuel system (10) for a combustion engine (102) of a vehicle (100), wherein the method comprises the steps of: determining a nominal amount of gaseous fuel to be introduced into the accumulator; introducing less gaseous fuel into the accumulator than the determined nominal amount by reducing or closing an inlet valve (24), which inlet valve is adapted to regulate input of gaseous fuel to the accumulator; and while the inlet valve is reduced or closed, performing at least one injection of gaseous fuel coming from the accumulator into at least one combustion chamber (104a-f) of the combustion engine by at least one injector (14a-f) of the fuel system, which at least one injection contributes to combustion in the combustion engine, thereby reducing pressure in the accumulator. The invention also relates to a corresponding fuel system (10).

A transport refrigeration system (20) having: a multi-fuel capable engine (26); a refrigeration unit (22) powered by the engine (26); a first fuel system (120, 130, 140, 150) operably connected to the engine (26), the first fuel (120, 130, 140, 150) system including at least one of a propane fuel system (120), compressed natural gas fuel system (130), liquefied natural gas fuel system (140), and gasoline fuel system (150); a second fuel system (120, 130, 140, 150) operably connected to the engine (26), the second fuel system (120, 130, 140, 150) including at least one of a propane fuel system (120), compressed natural gas fuel system (130), liquefied natural gas fuel system (140), and gasoline fuel system (150); and a controller (30) configured to command a fuel to the engine (26) from the first fuel system (120, 130, 140, 150) or the second fuel system (120, 130, 140, 150), the controller (30) adjusts operation of the engine (26) in response to the fuel commanded. The first fuel system (120, 130, 140, 150) operates on a fuel different than the second fuel system (120, 130, 140, 150). Both fuel systems (120, 130, 140, 150) are separate modules being removably connected to the engine (26).

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 for determining failure of an electromechanically actuated gas shut off valve includes sensing and recording a gas fuel rail pressure and a boost pressure from an air intake manifold at a first time after the dual fuel engine has been started. The method includes opening the gas shut off valve at a second time, holding the gas shut off valve in its open state, and then closing the gas shut off valve after a predetermined interval at a third time. The method includes comparing an actual gas rail pressure decay rate to a threshold gas rail pressure decay rate for the predetermined interval, and determining failure of the gas shut off valve when the actual gas rail pressure decay rate is less than the threshold gas rail pressure decay rate. Upon determining failure of the gas shut off valve, the method also includes initiating a mitigating action.