Pressure relief of a flange connection in overflow lines between a live steam valve and a high-pressure steam turbine inlet

Abstract

A steam turbine (1) having an upper housing part (4) and a lower housing part (5), in which the steam turbine (1) has at least one overflow line (18) between a live steam adjusting valve (8, 9) and a high-pressure steam turbine inlet, and the valve housing (14) of the live steam adjusting valve (8, 9) communicates with the overflow line (18) via a flange connection (27), and a live steam pipe (25) in the live steam adjusting valve (8, 9) is provided as a steam duct between the valve housing (14) and the overflow line (18), and a sealing element (19) is disposed between the live steam pipe (25) and a sealing seat (28) in the overflow line (18), is distinguished in that an annular chamber (24) between the live steam pipe (25) and the valve housing (14) is provided with a pressure relief line (21) into a chamber of lower pressure than the live steam pressure. As a result, an improved steam turbine with pressure relief of flanges in overflow lines between live steam adjusting valves and high-pressure steam turbine inlets is made available, and as a result the flange connections are lighter in weight and embodied with greater thermal elasticity.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a steam turbine having an upper housing part and a lower housing part, in which the steam turbine has at least one overflow line between a live steam adjusting valve and a high-pressure steam turbine inlet, and the valve housing of the live steam adjusting valve communicates with the overflow line via a flange connection, and a live steam pipe in the live steam adjusting valve is provided as a steam duct between the valve housing and the overflow line, and a sealing element is disposed between the live steam pipe and a sealing seat in the overflow line. [0002] From the prior art, steam turbines are known which have an upper and a lower housing part. To make for easier assembly and disassembly, the valves, or more precisely live steam adjusting valves or live steam overload valves, are secured directly to the upper housing part of the turbine. [0003] In such steam turbines, overflow lines are provided between the live ste...

AI Technical Summary

Benefits of technology

"The invention is an improved steam turbine with pressure relief of flanges in overflow lines between the live steam adjusting valves and the high-pressure steam turbine inlet. This design avoids the disadvantages of prior art and makes the flanges lighter and more flexible. The flange connections are designed to be lighter and more thermal elastic, minimizing the danger of leaks of steam to the outside in non-steady-state operation. The lower-pressure chamber can be the surrounding environment or a heat exchanger. The pressure relief line can communicate with the exhaust steam of the high-pressure turbine or other chambers at a lower pressure level. The sealing elements are piston rings that are temperature- and pressure-resistant. The pressure relief line can be integrated into the flange connection or provided separately. The flange connection is designed for a temperature difference of 550°C to 700°C."

Problems solved by technology

In the versions with a flange or pipe couplings, steam leakage often occurs when live steam values are high, that is, at a high temperature or high pressure in non-steady-state operation.

The tightness of the flanges or pipe couplings is therefore a problem in many steam turbine systems.

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