초록 ▼

Method and apparatus to limit and control rotational loss heating such as occurs in a large steam turbine in the bypass mode of operation under no-load and low-load operating conditions. According to the invention, a portion of the high pressure bypass steam is admitted to the lower pressure section

Method and apparatus to limit and control rotational loss heating such as occurs in a large steam turbine in the bypass mode of operation under no-load and low-load operating conditions. According to the invention, a portion of the high pressure bypass steam is admitted to the lower pressure sections of the turbine to provide motive fluid for driving the turbine while, simultaneously, a second portion of the high-pressure bypass steam is admitted to the high-pressure section of the turbine in a reverse-flow direction to pass backwards therethrough and limit the rotational loss heating. The two flows may be proportioned to control rotational loss heating in both the high-pressure and lower pressure sections of the turbine. A reverse-flow valve and a ventilator valve are provided for routing the reverse-flow of steam.

대표청구항 ▼

A method for operating a steam turbine adapted for bypass mode operation in conjunction with a steam generating means, the turbine having a high-pressure (HP) section, an HP bypass system, at least one lower pressure section, and a lower pressure bypass system, said method comprising the steps of: b

A method for operating a steam turbine adapted for bypass mode operation in conjunction with a steam generating means, the turbine having a high-pressure (HP) section, an HP bypass system, at least one lower pressure section, and a lower pressure bypass system, said method comprising the steps of: bypassing a flow of steam from said steam generating means around said HP section; admitting a first portion of said bypassed steam to said lower pressure section in a forward flow direction to provide motive fluid for driving the turbine, said first portion of steam being admitted at a rate sufficient to limit rotation loss heating in said lower pressure section; and admitting a second portion of said bypassed steam to said HP section to pass therethrough in a reverse-flow direction to limit rotation loss heating in said HP section and to provide an offsetting braking effect for said first portion of steam admitted to said lower pressure section in excess of that required for driving the turbine.