| 摘要 |
1,159,837. Measuring temperature electrically. GENERAL ELECTRIC CO. May 19, 1967 [Aug. 22, 1966], No. 23429/67. Heading G1N. The temperature T4 at the inlet 20, Fig. 1, of the turbine 22 stage of a gas turbine engine is obtained by measuring the air temperature T3 at the inlet to the combustion chamber 16 and adding to it, at 40, a signal obtained by combining the outputs of transducers 26, 30, 32 measuring respectively rotor speed N, combustion chamber inlet static pressure Ps3, and rate of fuel flow to the chamber Wf. The equation governing the combination of the various signals to give T4 includes a square root of T4 term and this is obtained by feeding the output of adding means 40 to a rooting circuit 42 and time delay 43, and injecting the resultant signal at a point 44 before the T3 term is added. The formula given is: The functions f of Ps3 and N are produced by function generators 48, 36, and a unit 33 supplies a signal A 4 proportional to the area of the turbine inlet 20, though this is normally fixed. The signal supplied by the dividing device 46 and representing wf.f(Ps3), may be derived alternatively by a Ps3 different circuit Fig. 2 (not shown); and the f(N) signal from 36 may be derived alternatively from a circuit Fig. 3 (not shown) which generates a different f(N) signal according to whether the engine is in steady operation or accelerating. Function generators (54, 56) continuously operate, and the appropriate output is selected at (58) by a device (60) which senses whether the measured speed N is less than or equal to a pre-set speed (62). The calculated temperature T4 may be used to control exhaust nozzle area, or to limit fuel flow.
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