초록

A turbine system includes a valve coupled to a leak off line from a leak packing of a first turbine, the valve controlling a first steam flow used to maintain a constant self-sustaining sealing pressure to a second turbine across numerous loading conditions. A related method is also provided.

대표청구항 ▼

1. A steam turbine system comprising: a high pressure (HP) turbine operatively coupled to an intermediate pressure (IP) turbine and a low pressure (LP) turbine;a steam seal header for maintaining a constant self-sustaining sealing pressure to the LP turbine using a first steam flow in a seal steam l

1. A steam turbine system comprising: a high pressure (HP) turbine operatively coupled to an intermediate pressure (IP) turbine and a low pressure (LP) turbine;a steam seal header for maintaining a constant self-sustaining sealing pressure to the LP turbine using a first steam flow in a seal steam line from a seal packing of the HP turbine;a leak off line coupling a leak packing of the HP turbine to the IP turbine;a connector line directly coupling the leak off line to the seal steam line upstream of the IP turbine;a valve coupled to the connector line for controlling the first steam flow to the steam seal header; anda controller for controlling operation of the valve,wherein the valve delivers more steam flow to the seal steam line during a lower load condition of the IP turbine than during a higher load condition of the IP turbine such that the steam seal header uses greater than or approximately 90% of the first steam flow to maintain a sealing pressure to the LP turbine, and the steam seal header leaves approximately 10% or less of the first steam flow unused during all load conditions of the turbine system. 2. The steam turbine system of claim 1, wherein the valve includes a diverter valve for controlling the first steam flow by diverting a portion of a second steam flow from the leak off line directly to the first steam flow in the seal steam line. 3. The steam turbine system of claim 1, wherein the steam seal header sends the unused portion of the first steam flow to a condenser. 4. The steam turbine system of claim 1, wherein the leak off line further includes a blocking valve. 5. A method of operating a turbine system, the method comprising: providing: a high pressure (HP) turbine operatively coupled to an intermediate pressure (IP) turbine and a low pressure (LP) turbine;a leak off line coupling a leak packing of the HP turbine to the IP turbine;a seal steam line coupling a seal packing of the HP turbine to a seal packing of the LP turbine by way of a steam seal header;a connector line directly coupling the leak off line to the seal steam line upstream of the IP turbine; anda valve coupled to the connector line; andmaintaining a constant self-sustaining sealing pressure to the LP turbine by: controlling the valve coupled to the connector line to deliver more steam to a first steam flow within the seal steam line during a lower load condition of the IP turbine than during a higher load condition of the IP turbine, such that the steam seal header uses greater than approximately 90% of the first steam flow and the steam seal header leaves approximately 10% or less of the first steam flow unused during all load conditions of the turbine system. 6. The method of claim 5, wherein the controlling includes diverting a portion of a second steam flow from the leak off line to the first steam flow in the steam seal line using the valve in the connector line. 7. The method of claim 5, wherein the steam seal header sends the unused portion of the first steam flow to a condenser. 8. A steam turbine system comprising: a high pressure (HP) turbine operatively coupled to an intermediate pressure (IP) turbine and a low pressure (LP) turbine;a steam seal header coupled to a seal packing of the LP turbine for maintaining a constant self-sustaining sealing pressure to the LP turbine;a first steam flow within a seal steam line coupling a seal packing of the HP turbine to the steam seal header;a leak off line coupling a leak packing of the HP turbine to the IP turbine;a connector line directly coupling the leak off line to the steam seal line upstream of the IP turbine and the steam seal header;a valve coupled to the connector line for controlling the first steam flow to the steam seal header;a blocking valve positioned in the leak off line upstream of the valve coupled to the connector line; anda controller for controlling operation of the valve,wherein the valve delivers more steam flow to the seal steam line during a lower load condition of the IP turbine than during a higher load condition of the IP turbine such that the steam seal header uses greater than approximately 90% of the first steam flow to maintain a sealing pressure to the LP turbine and the steam seal header sends approximately 10% or less of the first steam flow to a condenser during all load conditions of the turbine system. 9. The turbine system of claim 8, wherein the valve includes a diverter valve for controlling the first steam flow by diverting a portion of a second steam flow within the leak off line to the first steam flow within the seal steam line.