Method of controlling the geometrical configuration of a variable geometry element in a gas turbine engine compressor stage
AssigneePratt & Whitney Canada Corp.
InventorsMartin DROLET, Yves CLOUTIER
Life of this patent
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Abstract
The method can include determining a mass flow rate W of working fluid circulating through the compressor stage, determining a control parameter value associated to the geometrical configuration of the variable geometry element based on the determined value of mass flow rate W; and changing the geometrical configuration of the variable geometry element in accordance with the determined control parameter value.
Claims20
A method of controlling the geometrical configuration of a variable geometry element of a compressor stage of a gas turbine engine, the method comprising:
- determining a mass flow rate W of working fluid circulating through the compressor stage, including
- determining whether a difference between an expected value of normalized mass flow rate QHPT through a high-pressure turbine of the gas turbine engine and an actual value of normalized mass flow rate Qcurr through the high-pressure turbine exceeds a threshold value, wherein the actual value of normalized mass flow rate Qcurr is a function of a current value of mass flow rate Wcurrent, a current value of pressure Pcurrent, and a current value of temperature Tcurrent through the high-pressure turbine based on the relationship
- Wcurr·√{square root over (Tcurr)}/Pcurr=Qcurr;
- when the difference exceeds the threshold value, correcting the value of Wcurr;
- and
- outputting the value of W curr as a determined value of mass flow rate W;
- determining a control parameter value associated to the geometrical configuration of the variable geometry element based on the determined value of mass flow rate W;
- and
- changing the geometrical configuration of the variable geometry element in accordance with the determined control parameter value.
A computer program product stored in a non-transitory computer readable memory and comprising instructions operative to, when executed by a processor, perform a method of
- determining a mass flow rate W of working fluid circulating through the compressor stage, including
- determining whether a difference between an expected value of normalized mass flow rate QHPT through a high-pressure turbine of the gas turbine engine and an actual value of normalized mass flow rate Qcurr through the combustor exceeds a threshold value, wherein the actual value of normalized mass flow rate curr is Qcurr is a function of a current value of mass flow rate Wcurr, a current value of pressure Pcurr, and a current value of temperature Tcurr through the high-pressure turbine based on the relationship Wcurr·√{square root over (Tcurr)}/Pcurr=Qcurr, where difference is expected to be below the given threshold when the high-pressure turbine of the gas turbine engine operates in a choked condition;
- if the difference exceeds the threshold value, updating the value of Wcurr, and returning to the step of determining whether the difference exceeds the threshold value on the basis of the updated value of Wcurr, and
- if the difference does not exceed the threshold value, outputting the value of Wcurr as a determined value of mass flow rate W;
- and
- determining a control parameter value associated to the geometrical configuration of the variable geometry element based on the determined value of mass flow rate W.
A gas turbine engine comprising a compressor stage having a variable geometry element, a combustor and a turbine stage, and a controller having a processor and a memory, the memory having stored thereon instructions executable by the processor to
- determine a mass flow rate W of working fluid circulating through the compressor stage, including
- determining whether a difference between an expected value of normalized mass flow rate QHPT through the turbine stage and an actual value of normalized mass flow rate Qcurr through the high-pressure turbine exceeds a threshold, wherein the actual value of normalized mass flow rate Qcurr is related to a current value of mass flow rate Wcurr, a current value of pressure Pcurr, and a current value of temperature Tcurr through the high-pressure turbine,
- if the difference exceeds the threshold value, updating the value of Wcurr, and returning to the step of determining whether the difference exceeds the threshold value on the basis of the updated value of Wcurr;
- and
- if the difference does not exceed the threshold value, outputting the value of Wcurr as a determined value of mass flow rate W;
- determine a control parameter value associated to the geometrical configuration of the variable geometry element based on the determined value of mass flow rate W;
- and
- generate control instructions configured to change the geometrical configuration of the variable geometry element in accordance with the determined control parameter value.
Dependencies are inferred from the claim text.