| 摘要 |
<p>17TU-2792 SHELL AND TUBE MOISTURE SEPARATOR REHEATER WITH OUTLET ORIFICING Shell and tube heat exchangers achieve greater efficiency and substantially eliminate instabilities due to condensate subcooling by the location of flow restricting orifices at the outlet ends of heat exchanger tubes adjacent to the outlet header. Outlet orificing preferentially passes liquid condensate so as to prevent accumulation of condensate within the tubes and permits a higher tubeside temperature, even in themost heavily loaded tubes. In a two-pass configuration all tubes are outlet orificed. In a four-pass system, the most heavily loaded tubes (second pass) are orificed, although all tubes may be outlet orificed. Outlet orificing may be used in conjunction with inlet orificing which is used to provide greatest mass flow of tubeside steam to most heavily loaded tubes. Outlet orificing may be used in connection with vertical or horizontal U tube configurations. Preferred embodiment is utilized in a moisture separator reheater for use with steam turbines to reheat steam for later turbine stages. Orifices are restricted diameter apertured plugs in heat exchanger tubes located within the tubesheet adjacent to the header.</p> |
