A combustion system using at least 90 wt % propylene glycol based liquid fuel includes a first fuel tank, a wick inserted in the first tank, a sensing unit configured to receive an activating signal and sense the liquid level of the propylene glycol based liquid fuel in the first fuel tank and send a fuel replenishment signal accordingly, a second fuel tank, a conduit system connected with the first and the second fuel tanks, and a drive unit connected with the conduit system and configured to receive the fuel replenishment signal so as to cause the propylene glycol based liquid fuel in the second fuel tank to replenish the first fuel tank through the conduit system as well as to cool the wick.

A combustion system using at least 90 wt % propylene glycol based liquid fuel includes a first fuel tank, a wick inserted in the first tank, a sensing unit configured to receive an activating signal and sense the liquid level of the propylene glycol based liquid fuel in the first fuel tank and send a fuel replenishment signal accordingly, a second fuel tank, a conduit system connected with the first and the second fuel tanks, and a drive unit connected with the conduit system and configured to receive the fuel replenishment signal so as to cause the propylene glycol based liquid fuel in the second fuel tank to replenish the first fuel tank through the conduit system as well as to cool the wick.

A self-pumping fuel injector includes a pump and a motor for, in-part, delivering fuel to a combustor at higher fuel pressures during start-up and ramping-up conditions. Each pump may include a stationary flow interuptor that intermittently and variably supplies fuel to a rotating spindle that, in-turn, expels the fuel into a nozzle of the injector for improve fuel spray distributions.

A self-pumping fuel injector includes a pump and a motor for, in-part, delivering fuel to a combustor at higher fuel pressures during start-up and ramping-up conditions. Each pump may include a stationary flow interuptor that intermittently and variably supplies fuel to a rotating spindle that, in-turn, expels the fuel into a nozzle of the injector for improve fuel spray distributions.

Systems and methods are provided herein for tracking degradation of a high-pressure fuel pump. In one example, a fuel system controller is configured to receive an output pressure signal from a pressure sensor, transform the output pressure signal to the frequency domain to generate frequency content of the output pressure signal, and diagnose a condition of a fuel pump based at least in part on the frequency content of the output pressure signal, the fuel pump fluidly coupled to a fuel injector via a common fuel rail, and the fuel injector is operable to inject fuel to a cylinder of an engine.

Systems and methods are provided herein for tracking degradation of a high-pressure fuel pump. In one example, a fuel system controller is configured to receive an output pressure signal from a pressure sensor, transform the output pressure signal to the frequency domain to generate frequency content of the output pressure signal, and diagnose a condition of a fuel pump based at least in part on the frequency content of the output pressure signal, the fuel pump fluidly coupled to a fuel injector via a common fuel rail, and the fuel injector is operable to inject fuel to a cylinder of an engine.

A fuel oxygen conversion unit includes a contactor defining a liquid fuel inlet, a stripping gas inlet and a fuel/gas mixture outlet; and a fuel gas separator defining a fuel/gas mixture inlet in flow communication with the fuel/gas mixture outlet of the contactor and an axis. The fuel gas separator further includes a stationary casing; and a separator assembly including a core and a plurality of paddles extending from the core, the separator assembly rotatable about the axis within the stationary casing to separate a fuel/gas mixture received through the fuel/gas mixture inlet into a liquid fuel flow and stripping gas flow.

A fuel oxygen conversion unit includes a contactor defining a liquid fuel inlet, a stripping gas inlet and a fuel/gas mixture outlet; and a fuel gas separator defining a fuel/gas mixture inlet in flow communication with the fuel/gas mixture outlet of the contactor and an axis. The fuel gas separator further includes a stationary casing; and a separator assembly including a core and a plurality of paddles extending from the core, the separator assembly rotatable about the axis within the stationary casing to separate a fuel/gas mixture received through the fuel/gas mixture inlet into a liquid fuel flow and stripping gas flow.

A fuel supply control device (10) is configured to generate an operation amount used for feedback-controlling rotation of a gear pump (3) based on a deviation of a detected fuel flow rate with respect to a target flow rate, wherein the fuel supply control device generates the operation amount such that a rotation speed of the gear pump is equal to or greater than a predetermined lower limit rotation speed Nmin so as to protect a bearing of the gear pump.

A fuel supply control device (10) is configured to generate an operation amount used for feedback-controlling rotation of a gear pump (3) based on a deviation of a detected fuel flow rate with respect to a target flow rate, wherein the fuel supply control device generates the operation amount such that a rotation speed of the gear pump is equal to or greater than a predetermined lower limit rotation speed Nmin so as to protect a bearing of the gear pump.