| 摘要 |
A flow by-pass system is provided in a downward-discharging exhaust hood of a steam turbine to by-pass a small percentage of the total steam flow from the top portion of the exhaust hood to the vicinity of the condenser and in that way relieve excess pressure in the top portion incident to the more convoluted path of the main portion of steam passing from the top to the bottom and to decrease energy loss caused by friction and thus to improve turbine efficiency. The flow by-pass system includes by-pass conduits within the front portion of the exhaust hood extending from the top portion to the vicinity of the condenser. Such conduits are formed by covering over the corners between the outer and end walls of the exhaust hood and between the exhaust hood end wall and the bearing cone outside surface with by-pass walls to form flow passages in the corners behind the by-pass walls through which exhaust steam may pass from the region of higher pressure in the top portion of the exhaust hood to the region of lower pressure in vicinity of the condenser. Inlets and outlets are provided in the by-pass walls for entrance and exit of the turbine exhaust steam to the by-pass conduits.
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