Fuel pump with built-in thermal bypass
A fuel delivery system for a gas turbine engine includes a fuel source, a main fuel pump configured to deliver a first flow of fuel to a combustor assembly of the gas turbine engine, a main fuel filter positioned upstream of the main fuel pump, and an actuation pump disposed upstream of the main fuel filter and configured to deliver a second flow of fuel from the fuel source to one or more actuation devices of the gas turbine engine.
1 . A fuel delivery system for a gas turbine engine, comprising:
a fuel source;
a main fuel pump configured to deliver a first flow of fuel to a combustor assembly of the gas turbine engine;
a main fuel filter disposed upstream of the main fuel pump;
an actuation pump disposed upstream of the main fuel filter and configured to deliver a second flow of fuel from the fuel source to one or more actuation devices of the gas turbine engine; and
a thermal bypass valve located downstream of the actuation pump and configured to be activated when a temperature of the second flow of fuel exceeds a predetermined threshold, to increase a volume of the second flow of fuel through the actuation pump, thereby decreasing the temperature of the second flow of fuel;
wherein when the thermal bypass valve is activated the second flow of fuel is directed to the main fuel filter.
2 . The fuel delivery system of claim 1 , further comprising a boost pump positioned upstream of the main fuel filter and the actuation pump.
3 . The fuel delivery system of claim 2 , further comprising a wash filter disposed fluidly between the boost pump and the main fuel filter.
4 . The fuel delivery system of claim 3 , wherein the actuation pump is fed from the wash filter.
5 . The fuel delivery system of claim 2 , wherein the second flow of fuel is urged from the one or more actuation devices to an outlet of the boost pump.
6 . The fuel delivery system of claim 1 , wherein the thermal bypass valve is one of actively controlled or thermostatically controlled.
7 . The fuel delivery system of claim 1 , further comprising a high pressure relief valve disposed downstream of the actuation pump and configured when activated to direct the second flow of fuel toward the main fuel filter when a pressure of the second flow of fuel exceeds a predetermined threshold.
8 . The fuel delivery system of claim 1 , wherein the actuation pump is a variable displacement pump.
9 . A gas turbine engine and fuel delivery system, comprising:
a gas turbine engine, including:
a turbine; and
a combustor where a first flow of fuel is combusted to drive the turbine via a flow of combustion products; and
a fuel delivery system operably connected to the gas turbine engine, including:
a fuel source;
a main fuel pump configured to deliver a first flow of fuel to the combustor;
a main fuel filter disposed upstream of the main fuel pump;
an actuation pump disposed upstream of the main fuel filter and configured to deliver a second flow of fuel from the fuel source to one or more actuation devices of the gas turbine engine; and
a thermal bypass valve located downstream of the actuation pump and configured to be activated when a temperature of the second flow of fuel exceeds a predetermined threshold, to increase a volume of the second flow of fuel through the actuation pump, thereby decreasing the temperature of the second flow of fuel;
wherein when the thermal bypass valve is activated the second flow of fuel is directed to the main fuel filter.
10 . The gas turbine engine and fuel delivery system of claim 9 , further comprising a boost pump positioned upstream of the main fuel filter and the actuation pump.
11 . The gas turbine engine and fuel delivery system of claim 10 , further comprising a wash filter disposed fluidly between the boost pump and the main fuel filter.
12 . The gas turbine engine and fuel delivery system of claim 11 , wherein the actuation pump is fed from the wash filter.
13 . The gas turbine engine and fuel delivery system of claim 10 , wherein the second flow of fuel is urged from the one or more actuation devices to an outlet of the boost pump.
14 . The gas turbine engine and fuel delivery system of claim 9 , wherein the thermal bypass valve is one of actively controlled or thermostatically controlled.
15 . The gas turbine engine and fuel delivery system of claim 9 , further comprising a high pressure relief valve disposed downstream of the actuation pump and configured when activated to direct the second flow of fuel toward the main fuel filter when a pressure of the second flow of fuel exceeds a predetermined threshold.
16 . The gas turbine engine and fuel delivery system of claim 9 , wherein the actuation pump is a variable displacement pump.
17 . A fuel delivery system for a gas turbine engine, comprising:
a fuel source;
a main fuel pump configured to deliver a first flow of fuel to a combustor assembly of the gas turbine engine;
a main fuel filter disposed upstream of the main fuel pump;
an actuation pump disposed upstream of the main fuel filter and configured to deliver a second flow of fuel from the fuel source to one or more actuation devices of the gas turbine engine; and
a thermal bypass valve located downstream of the actuation pump and configured to be activated when a temperature of the second flow of fuel exceeds a predetermined threshold;
wherein when the thermal bypass valve is activated the second flow of fuel is directed to the main fuel filter.