Abstract:
A gas turbine engine fuel supply system includes a primary gear pump and a secondary gear pump. The primary gear pump always actively delivers fuel to the downstream fuel system, and is sized to supply 100% of the burn flow needed at a select low demand condition. The secondary gear pump is sized to make up the remainder of the flow at high demand conditions, and actively delivers fuel to the downstream fuel system only during those conditions. To supply discharge fuel pressures in excess of gear pump capability, a supercharger pump is disposed upstream of the primary and secondary gear pumps. The supercharger pump is preferably activated only during high demand conditions as an additional energy conservation measure.
Abstract:
A two-position, two-stage servo valve includes a valve body, a valve element, a control pressure chamber, and a control element. The valve body has an inner surface that defines a valve element chamber that includes a first control chamber and a second control chamber. The first control chamber is larger than the second control chamber. The valve element has first and second ends and is disposed within the valve element chamber and is movable between a first valve position and a second valve position. The first end is larger than the second end and is disposed within the first control chamber, and the second end is disposed within the second control chamber. The control pressure chamber includes a control pressure port that is in continuous fluid communication with the first control chamber. The control element is movable between a first control position and a second control position.
Abstract:
A gas turbine engine fuel supply system includes a primary gear pump and a secondary gear pump. The primary gear pump always actively delivers fuel to the downstream fuel system, and is sized to supply 100% of the burn flow needed at a select low demand condition. The secondary gear pump is sized to make up the remainder of the flow at high demand conditions, and actively delivers fuel to the downstream fuel system only during those conditions. To supply discharge fuel pressures in excess of gear pump capability, a supercharger pump is disposed upstream of the primary and secondary gear pumps. The supercharger pump is preferably activated only during high demand conditions as an additional energy conservation measure.
Abstract:
A system uses a two-stage electrohydraulic servo valve that includes an additional control port that commands a fail-fixed valve to lock the position of a device in the last commanded position. The additional port is modulated by an existing land on the EHSV valve element, adding little to no complexity. Major technical benefits of the disclosed system are that it adds little to no cost, complexity, size, or weight the device being controlled. The disclosed configuration allows for the use of a relatively small and simple fail-fixed valve, and the control ports on the controlled device keep “drift” to a minimum, when transitioning between normal operating mode and fail-fixed operating mode.
Abstract:
Embodiments of a combined overspeed and fuel stream selector system are provided. In an embodiment, the assembly includes a conduit network, a Discharge Select Valve (DSV), and a shutoff valve. The DSV is fluidly coupled to a primary fuel inlet, a secondary fuel inlet, and a primary fuel outlet included in the conduit network. The shutoff valve is fluidly coupled between the primary fuel inlet and the primary fuel outlet. In a standard operation mode, the shutoff valve is maintained in an open position, while fuel received at the primary fuel inlet is directed through the shutoff valve, through the DSV, and to the primary fuel inlet. Conversely, in a backup operation mode, the shutoff valve is closed to block fuel flow from the primary fuel inlet to the primary fuel outlet, while the DSV directs fuel flow received at the secondary fuel inlet to the primary fuel outlet.
Abstract:
A fuel supply system includes a fuel supply line, a fuel filter, a filter bypass line, a first differential pressure sensor, a second differential pressure sensor, and a filter bypass valve. The fuel filter is disposed in series in the fuel supply line to remove particulate from the fuel. The filter bypass line has a fuel inlet upstream of the fuel filter, and an outlet that is downstream of the fuel filter. The first differential pressure sensor continuously senses differential pressure across the fuel filter, and the second differential pressure sensor selectively senses differential pressure across the fuel filter. The filter bypass valve is movable between a first non-bypassing position and a second bypassing position and controls whether only the first differential pressure sensor or both the first and second differential pressure sensors sense the differential pressure across the fuel filter.
Abstract:
A fuel supply system includes a fuel supply line, a fuel filter, a filter bypass line, a first differential pressure sensor, a second differential pressure sensor, and a filter bypass valve. The fuel filter is disposed in series in the fuel supply line to remove particulate from the fuel. The filter bypass line has a fuel inlet upstream of the fuel filter, and an outlet that is downstream of the fuel filter. The first differential pressure sensor continuously senses differential pressure across the fuel filter, and the second differential pressure sensor selectively senses differential pressure across the fuel filter. The filter bypass valve is movable between a first non-bypassing position and a second bypassing position and controls whether only the first differential pressure sensor or both the first and second differential pressure sensors sense the differential pressure across the fuel filter.
Abstract:
Embodiments of a combined overspeed and fuel stream selector system are provided. In an embodiment, the assembly includes a conduit network, a Discharge Select Valve (DSV), and a shutoff valve. The DSV is fluidly coupled to a primary fuel inlet, a secondary fuel inlet, and a primary fuel outlet included in the conduit network. The shutoff valve is fluidly coupled between the primary fuel inlet and the primary fuel outlet. In a standard operation mode, the shutoff valve is maintained in an open position, while fuel received at the primary fuel inlet is directed through the shutoff valve, through the DSV, and to the primary fuel inlet. Conversely, in a backup operation mode, the shutoff valve is closed to block fuel flow from the primary fuel inlet to the primary fuel outlet, while the DSV directs fuel flow received at the secondary fuel inlet to the primary fuel outlet.
Abstract:
A gas turbine engine fuel supply system includes a primary gear pump, a secondary gear pump, and a pump bypass valve. The primary gear pump always actively delivers fuel to the downstream fuel system, and is sized to supply 100% of the burn flow needed at a select low demand condition. The secondary gear pump is sized to make up the remainder of the flow at high demand conditions, and actively delivers fuel to the downstream fuel system only during those conditions. To supply discharge fuel pressures in excess of gear pump capability, a supercharger pump is disposed upstream of the primary and secondary gear pumps. The pump bypass valve is configured to regulate fuel pressure at the primary gear pump outlet to one of a plurality of preset differential pressures above one of a plurality of fuel load pressures and prevents reverse pressurization of the gear pumps.
Abstract:
A system uses a two-stage, four-way electrohydraulic servo valve that includes an additional control port that commands a fail-fixed valve to lock the position of a device in the last commanded position. The additional port is modulated by an existing land on the EHSV valve element, adding little to no complexity. Major technical benefits of the disclosed system are that it adds little to no cost, complexity, size, or weight the device being controlled. The disclosed configuration allows for the use of a relatively small and simple fail-fixed valve, and the control ports on the controlled device keep “drift” to a minimum, when transitioning between normal operating mode and fail-fixed operating mode.