Combination of a gas turbine engine and a power electronics
A combination of a gas turbine engine and a power electronics for powering aircraft and/or engine systems. The engine includes an engine core comprising a turbine, a combustor, a compressor, and a core shaft connecting the turbine to the compressor, and a fuel circuit for supplying a fuel flow to the combustor. The power electronics is configured to transfer heat produced by the power electronics to a cooling flow formed by a portion of the fuel flow. The fuel circuit is configured to circulate the cooling flow in a loop during selected engine conditions such that the cooling flow transfers heat from the power electronics to a phase change material located on the loop. The phase change material has a phase change temperature at a predetermined limiting temperature whereby the phase change material stores heat from the cooling flow to prevent the power electronics exceeding the limiting temperature.
1. A combination of a gas turbine engine and power electronics for powering aircraft and/or engine systems, wherein
the engine includes:
an engine core comprising a turbine, a combustor, a compressor, and a core shaft connecting the turbine to the compressor; and
a fuel circuit for supplying a fuel flow to the combustor;
the fuel circuit includes:
a fuel tank;
a low pressure pump arranged downstream of the fuel tank and configured to pressurise fuel to a low pressure;
a high pressure pump configured to receive the low pressure fuel and increase the pressure to a high pressure for onward supply to a fuel metering system;
a loop configured to circulate a portion of the low pressure fuel in the loop during selected engine conditions;
a phase change material located on the loop, such that the portion of the low pressure fuel transfers heat from the power electronics to the phase change material, the phase change material having a phase change temperature at a predetermined limiting temperature whereby the phase change material stores heat from the portion of the low pressure fuel, which prevents the power electronics from exceeding the limiting temperature;
a cooling pump on the loop configured to drive only the portion of the low pressure fuel; and
the loop is formed downstream of an outlet of the low pressure pump and upstream of an inlet of the high pressure pump.
2. The combination of the gas turbine engine and the power electronics according to claim 1 , wherein the selected engine conditions include any one or more of: sub-idle engine operation, low-power engine operation, transition from end of cruise to top of descent operation, and post-shutdown heat soak back.
3. The combination of the gas turbine engine and the power electronics according to claim 1 , wherein the fuel circuit is configured to direct the portion of the low pressure fuel into the combustor during operation of the engine under other conditions.
4. The combination of the gas turbine engine and the power electronics according to claim 1 , wherein an air-cooled heat exchanger is located on the loop to transfer heat from the portion of the low pressure fuel to an airflow produced by the engine.
5. The combination of the gas turbine engine and the power electronics according to claim 1 , wherein the phase change temperature of the phase change material is 100° C. or less.
6. The combination of the gas turbine engine and the power electronics according to claim 1 , wherein the phase change material is configured to store at least 0.3 MJ of heat.
7. The combination of the gas turbine engine and the power electronics according to claim 1 , wherein the phase change material is a silicate salt or paraffin.
8. The combination of the gas turbine engine and the power electronics according to claim 1 , wherein the power electronics further includes internal passages for flow therethrough of the portion of the low pressure fuel.
9. The combination of the gas turbine engine and the power electronics according to claim 1 , wherein the power electronics further includes one or more cold plates cooled by the portion of the low pressure fuel for extracting heat produced by the power electronics.
10. The combination of the gas turbine engine and the power electronics according to claim 1 , wherein the cooling pump is an electric pump.
11. The combination of the gas turbine engine and the power electronics according to claim 1 , wherein the engine further includes: a fan located upstream of the engine core, the fan comprising a plurality of fan blades; and a gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft.
12. The combination of the gas turbine engine and the power electronics according to claim 11 , wherein: the turbine is a first turbine, the compressor is a first compressor, and the core shaft is a first core shaft; the engine core further includes a second turbine, a second compressor, and a second core shaft connecting the second turbine to the second compressor; and the second turbine, second compressor, and second core shaft are arranged to rotate at a higher rotational speed than the first core shaft.
13. The combination of the gas turbine engine and the power electronics according to claim 1 , wherein the portion of the low pressure fuel is diverted from a fuel line at an offtake upstream of the inlet of the high pressure pump and returned to the fuel line upstream of the offtake.
14. The combination of the gas turbine engine and the power electronics according to claim 13 , wherein the portion of the low pressure fuel is returned to the fuel line downstream of the outlet of the low pressure pump.