Steam power installation comprising valve-stem leakage steam line

1. A steam power plant comprising

a steam turbine,

a steam line that is fluidically connected to the steam turbine and is designed to convey steam,

a valve that is arranged in the steam line and is designed to change a quantity of steam flowing through the steam line, the valve comprising a first outlet to which the steam line connects, and a second outlet configured to convey valve-stem leakage steam that leaks past a valve stem of the valve,

a valve-stem leakage steam line connected to the second outlet, and

a valve-stem leakage steam collector that is fluidically connected to the valve-stem leakage steam line, and

a fitting that is arranged in the valve-stem leakage steam line,

wherein the valve-stem leakage steam collector is designed as a condenser,

wherein the valve-stem leakage steam is conveyed via the valve-stem leakage steam line directly from the second outlet to the condenser, and

wherein the fitting is configured to open whenever a pressure of valve-stem leakage steam in the valve-stem leakage steam line upstream of the fitting is above a pressure in the condenser, thereby passing all of the valve-stem leakage steam into the condenser.

2. The steam power plant as claimed in claim 1 ,

wherein the fitting is designed as a flap.

3. The steam power plant as claimed in claim 2 ,

wherein the flap is designed such that it is controlled.

4. The steam power plant as claimed in claim 2 ,

wherein the flap is designed as a check flap.

5. The steam power plant as claimed in claim 1 ,

wherein the fitting is designed as a valve.

6. The steam power plant as claimed in claim 1 , further comprising:

a safety valve arranged in the valve-stem leakage steam line.

7. A method for operating a steam power plant,

wherein the steam power plant comprises:

a steam turbine,

a steam line that is fluidically connected to the steam turbine and is designed to convey steam,

a valve that is arranged in the steam line and is designed to change a quantity of steam flowing through the steam line, the valve comprising a first outlet to which the steam line connects, and a second outlet configured to convey valve-stem leakage steam that leaks past a valve stem of the valve,

a valve-stem leakage steam line connected to the second outlet, and

a valve-stem leakage steam collector that is fluidically connected to the valve-stem leakage steam line, and

a fitting that is arranged in the valve-stem leakage steam line,

wherein the valve-stem leakage steam collector is designed as a condenser,

wherein the valve-stem leakage steam is conveyed via the valve-stem leakage steam line directly from the second outlet to the condenser,

the method comprising:

opening the fitting whenever a pressure of valve-stem leakage steam in the valve-stem leakage steam line upstream of the fitting is above a pressure in the condenser to pass all of the valve-stem leakage steam to the condenser, and

closing the fitting whenever the pressure of valve-stem leakage steam in the valve-stem leakage steam line upstream of the fitting is below the pressure in the condenser.

8. The method as claimed in claim 7 ,

wherein a safety valve in the valve-stem leakage steam line opens to release more than a maximum pressure in the valve-stem leakage steam line.

9. A steam power plant, comprising:

a first flow circuit in which steam flows into a steam valve, then out the steam valve via a first valve outlet, then through a steam line to a steam turbine; and

a second flow circuit in which the steam flows into the steam valve, then leaks past a valve stem and a housing of the steam valve, then flows out the steam valve via a second outlet, then through a fitting configured to open whenever a pressure of the steam at the second outlet is above a pressure in a condenser, and then directly to the condenser.

10. The steam power plant of claim 9 , wherein the fitting comprises a check flap.