A fuel system includes a first fuel line carrying fuel at a first line pressure (P22), a second fuel line carrying fuel at a second line pressure (PFNC) greater than the first line pressure (P22), at least one pressure regulating section 102 having an input 101 connected to the second fuel line and at least one output (103), a first pressure regulator (120) connected to the input and a second pressure regulator (130) connected between the first pressure regulator (120) and the at least one output (103), and a controller (160) controlling the position of the first and second pressure regulators (120, 130) to produce at the output (103) one of a predetermined number of output pressures relative to the first line pressure (P22).

A fluid flow system for a gas turbine engine provides combustion fuel to a main pump and an actuator pump significantly reducing heat generation at low flow demand, while regulating actuator flow temperature at high flow demand. Fuel flow from the actuator pump in excess of the actuators needs is directed through an actuator minimum pressure valve and into a thermal bypass valve (TBV.) Depending upon the temperature of the fuel, the TBV determines the path of the excess actuator pump fluid flow. The TBV divides the fuel flow between being recirculated to the actuator pump inlet and the main pump output flow path to the engine fuel input conduit. The engine actuators are thereby assured of receiving flow which preclude freezing of water entrained in the fuel. When there is minimal concern with the possibility of freezing water entrained in the fuel, the TBV passes a greater percentage of fuel through to join together in the engine fuel input conduit.

A gas transfer system and method for dissolving at least one gas into a liquid. The system includes a gas transfer vessel also known as a reactor. A liquid inlet feed is connected to the reactor for transferring the liquid into the reactor. A gas inlet is connected to the reactor for feeding the gas into the reactor. An outlet is connected to the reactor for transferring the liquid with at least some of the gas therein away from the reactor. The system also includes a feed pump connected to the inlet feed to pressurize the contents of the inlet feed and the reactor, and a regenerative turbine connected to the feed pump and to the outlet. The various embodiments of the gas transfer system use pressurization in the gas transfer vessel to enhance gas transfer therein, minimize the net energy consumption, and retain highly supersaturated dissolved gas in solution. Some embodiments further help to reduce effervescence loss. The method of the present invention utilizes the system of the present invention and operates the feed pump and regenerative turbine to accomplish these advantages.

A system and method for control of a gas and/or chemical for treatment of a fluid, and for monitoring the operation of such a system. In one embodiment, the system comprises a reactor for receipt of the fluid and the gas and/or chemical for dissolving, mixing, diffusing, or infusing the gas and/or chemical into the fluid, and a controller to control the flow of the fluid and the gas and/or chemical into the reactor, and to monitor the operation of the system in accordance with predetermined operating conditions. In another embodiment, the system also comprises a gas/chemical generation system for generation of the gas and/or chemical to be introduced into the reactor. The present invention permits for the control of the system based on numerous dynamic conditions to optimize operation and to minimize safety hazards.

A gas transfer system and method for dissolving at least one gas into a liquid. The system includes a gas transfer vessel also known as a reactor. A liquid inlet feed is connected to the reactor for transferring the liquid into the reactor. A gas inlet is connected to the reactor for feeding the gas into the reactor. An outlet is connected to the reactor for transferring the liquid with at least some of the gas therein away from the reactor. The system also includes a feed pump connected to the inlet feed to pressurize the contents of the inlet feed and the reactor, and a regenerative turbine connected to the feed pump and to the outlet. The various embodiments of the gas transfer system use pressurization in the gas transfer vessel to enhance gas transfer therein, minimize the net energy consumption, and retain highly supersaturated dissolved gas in solution. Some embodiments further help to reduce effervescence loss. The method of the present invention utilizes the system of the present invention and operates the feed pump and regenerative turbine to accomplish these advantages.