Power plant with emergency fuel system
View Patent ↗A method for operating a power plant having a gas turbine and an emergency fuel system where in a normal operating state, gas is supplied from a supply line to the combustion process of the gas turbine, and in addition gas is supplied from the supply line to a gas liquefaction plant where it is liquefied, forming a liquid gas which is stored in a liquid gas store. In special operating state, liquefied gas is drawn from the liquid gas store and is evaporated in an evaporator, and is fed in the gaseous state into the combustion process of the gas turbine.
1. A method for operating a power plant comprising a gas turbine and an emergency fuel system, the method comprising:
receiving into a supply line a supply gas from an external source, wherein the supply line is connected to a combustion process of the gas turbine, and wherein the supply line comprises a liquefaction process outlet,
a liquefaction line connected to a gas liquefaction plant and comprising a liquefaction line inlet connected to the liquefaction process outlet,
in a first operating state, feeding the supply gas from the supply line to the combustion process of the gas turbine, and, in addition, feeding the supply gas from the liquefaction process outlet to the liquefaction line to supply the gas liquefaction plant and liquefying the supply gas therein, wherein a composition of the supply gas is not changed, wherein a liquefied gas is formed and stored in a liquefied gas tank,
in a second operating state, extracting the liquefied gas from the liquefied gas tank, and evaporating the liquefied gas in an evaporator to form an evaporated gas, and feeding the evaporated gas into the combustion process of the gas turbine, and
in the second operating state, feeding the evaporated gas from the liquefied gas tank back into the supply line in order to compensate for pressure fluctuations in the supply line or, in the event of a complete loss of supply gas, to supply other consumers which are connected to the supply line with the evaporated gas.
2. The method as claimed in claim 1 ,
wherein, in the gas liquefaction plant, less than 5% of electric power of the power plant is used for liquefaction of the supply gas.
3. The method as claimed in claim 1 ,
wherein, in the second operating state, cold energy which becomes free during evaporation in the evaporator is used for cooling intake air of the gas turbine.
4. The method as claimed in claim 1 ,
wherein the gas liquefaction plant is additionally used in the first operating state in order to utilize power control of the power plant by controlled start-up or shutdown of said gas liquefaction plant.
5. The method as claimed in claim 4 ,
wherein the gas liquefaction plant is additionally used in the first operating state for frequency control or frequency back-up.
6. The method as claimed in claim 1 , wherein the supply gas fed to the combustion process of the gas turbine comprises liquefied natural gas, and the supply gas fed to the gas liquefaction plant comprises the liquefied natural gas.
7. The method as claimed in claim 1 , wherein the supply gas from the external source, the supply gas fed to the combustion process of the gas turbine, and the supply gas fed to the gas liquefaction plant comprise liquefied natural gas.
8. A method for operating a power plant comprising a gas turbine and an emergency fuel system, the method comprising:
feeding supply gas from an external source to a combustion process of the gas turbine in a first operating state,
feeding a flow of the supply gas from the external source to a gas liquefaction plant without changing a composition of the flow of the supply gas therebetween, liquefying the supply gas in the gas liquefaction plant to form a liquefied gas, and storing the liquefied gas in a liquefied gas tank in the first operating state, and
extracting the liquefied gas from the liquefied gas tank, evaporating the liquefied gas in an evaporator to form an evaporated gas, and feeding the evaporated gas into the combustion process of the gas turbine in a second operating state,
wherein in the first operating state the power plant is supplied with supply gas from the external source, and
wherein in the second operating state the evaporated gas is fed back into a supply line that leads to the combustion process.
9. The method as claimed in claim 8 , wherein the supply gas is fed from the external source to a supply line, and wherein the supply line branches into a combustion line that supplies the supply gas to the combustion process and into a liquefaction line that supplies the supply gas to the gas liquefaction plant.