| 摘要 |
1,040,422. Automatic control systems; programmed electric control. RICHARDSONS WESTGARTH & CO. Ltd. Feb. 27, 1963 [Feb. 28, 1962], No. 7885/62. Heading G3N and G3R. In a system for the programmed starting or stopping of a steam turbine the programme is automatically modified to keep a signal dependent upon differential temperatures and/or the rate of change of a single temperature within limits. As shown, the temperature differential across the inner and outer walls of the turbine casing is measured by detectors at 12, 14 and absolute casing temperature at 10. The resulting signals F2, F1, after transistor amplification at 22, 24 pass to a servo 42 which produces an output F3 if F2 or rate of change of F1 are outside prescribed limits. F3 operates a servomotor 40 to modify the operation of a programme device 28 controlling the steam supply apparatus 38. The device 28 comprises an autotransfer whose tapping is varied by a motor at a predetermined rate. The programme may also be modified by a second servo system 34, 36 operative when the difference between turbine speed detected at 30 and the programmed speed F5 is sufficiently large. In an alternative arrangement (Fig. 3, not shown) the temperature control is combined with an arrangement whereby turbine acceleration is compared with a variable reference, the difference controlling the steam supply; the temperature servo motor adjusts this reference value. |
