| 摘要 |
A steam turbine in which the number of shell penetrations is reduced to six, without the use of T or Y fittings, by controlling steam flow to large nozzle chambers with a single large valve, rather than two smaller size valves. Secondly, adjacent valves are oriented in opposite directions, with those valves controlling nozzle chambers in the upper casing of the turbine opening to provide downward flow. This arrangement achieves two benefits: first, it reduces the number of turns and the length of the "spaghetti" piping leading to the nozzle inlet snouts, providing a straighter and more direct route for steam flow: and secondly, the inversion of adjacent valves allows room for installation of individual servomotors for each valve, which in turn enables greater flexibility in valve actuation sequencing. The invention also provides an improved method of valve sequencing.
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