Steam seal header, method of using a steam seal header and steam turbine system incorporating a steam seal header

Abstract

A steam turbine system for use in a power plant includes a steam seal header that collects steam from seals of a high pressure steam turbine and an intermediate pressure steam turbine. The collected steam is provided to seals of a low pressure steam turbine to ensure the seals provide an effective seal for the low pressure steam turbine. Steam from the low pressure steam turbine is also collected in the steam seal header and it is mixed with the steam collected from the high and intermediate pressure seals. The mixed steam is then provided to drive the low pressure steam turbine.

Description

BACKGROUND OF THE INVENTION[0001]Steam turbine systems are often an integral portion of a power plant. In some instances, the steam turbines can also be a part of a combined cycle power plant which also includes one or more gas turbines. Thermal energy is used to produce steam which drives the steam turbines. The steam turbines drive a generator which produces electricity.[0002]The steam turbine system can include a high pressure steam turbine, an intermediate pressure steam turbine and a low pressure steam turbine, all of which are connected to a common rotating shaft that drives a generator. In some instances, the different steam turbines could be coupled to different shafts which drive different generators. Regardless, seals are used to seal the steam turbines to the rotating shaft.[0003]The seals which seal the steam turbines onto a rotating shaft require a certain amount of steam pressure in order to provide an effective seal. The seals used on high pressure steam turbines and ...

AI Technical Summary

Benefits of technology

This patent is about a method and system that involves using steam from high and low pressure steam turbines to improve the performance of a seal in a steam seal header. The technical effect of this invention is to provide a more efficient and effective seal in a steam turbine system, leading to better performance and reliability.

Problems solved by technology

However, in some instances, and under some operating conditions, the low pressure steam turbine may not be capable of providing enough pressure to its seals to ensure an effective seal.

Unfortunately, routing this excess steam to the condenser essentially wastes the energy present in this high temperature, high pressure steam.

As a result, configuring the steam turbine system as illustrated in FIG. 1 results in a less efficient operation that would otherwise be possible.

Often, the temperature and pressure of this collected steam is too high to be directly used in the low pressure steam turbine 130.

Although the configuration illustrated in FIG. 2 allows energy in the excess steam to be used to drive the generator 140, the cost of the attemperator 260 is often too high to justify the additional energy which is produced by this configuration.

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