Pump turbine plant
There is provided a method of operating a pump turbine plant including a turbine with a turbine impeller and a turbine spiral casing having a first pressure pipe, and a pump with a pump impeller and a pump spiral casing having a second pressure pipe; an electrical machine dynamically in a drive connection with a shaft, the pump turbine plant further including a hydraulic short-circuit that can be created between the turbine and the pump, wherein the turbine has a greater rated power than the pump, and wherein the turbine and the pump operate under partial load at least temporarily in the hydraulic short-circuit. The method further includes operating the turbine or the pump in the hydraulic short-circuit when a degree of efficiency of the pump and of the turbine in the hydraulic short-circuit is greater than a degree of efficiency of the turbine on its own.
1. A method of operating a pump turbine plant including a turbine with a turbine impeller and a turbine spiral casing having a first pressure pipe, and a pump with a pump impeller and a pump spiral casing having a second pressure pipe, an electrical machine dynamically in a drive connection with a shaft, the pump turbine plant further including a hydraulic short-circuit that can be created between the turbine and the pump, wherein the turbine has a greater rated power than the pump, and wherein the turbine and the pump operate under partial load at least temporarily in the hydraulic short-circuit, the method comprising:
operating the turbine or the pump in the hydraulic short-circuit when a degree of efficiency of the pump and of the turbine in the hydraulic short-circuit is greater than a degree of efficiency of the turbine on its own.
2. The method according to claim 1 , wherein:
at least one of the turbine and the pump has an adjustable guide apparatus;
a rated power N T of the turbine is up to five times larger than a rated power Np of the pump;
the turbine spiral casing and the pump spiral casing are supported against one another; and
the first pressure pipe and the second pressure pipe emerge in a common pressure line.
3. The method according to claim 2 , wherein the electrical machine is situated in an intermediate space between the turbine spiral casing and the pump spiral casing.
4. The method according to claim 2 , wherein the electrical machine is situated outside of an intermediate space between the turbine spiral casing and the pump spiral casing.
5. The method according to claim 2 , wherein the turbine spiral casing and the pump spiral casing are supported directly by a supporting element, wherein the supporting element comprises a cylindrical supporting ring or a supporting cone.
6. The method according to claim 3 , wherein the turbine spiral casing and the pump spiral casing are supported directly by a supporting element, a cylindrical supporting ring or a supporting cone.
7. The method according to claim 4 , wherein the turbine spiral casing and the pump spiral casing are supported directly by a supporting element, wherein the supporting element comprises a cylindrical supporting ring or a supporting cone.