Gas turbine plant and exhaust carbon dioxide recovery method therefor

1. A gas turbine plant comprising:

a gas turbine configured to receive fuel in accordance with a required output, combust the fuel, and be driven by a combustion gas generated by combusting the fuel;

an exhaust line configured to guide an exhaust gas exhausted from the gas turbine to an outside;

a carbon dioxide recovery device provided on the exhaust line and configured to recover carbon dioxide contained in the exhaust gas flowing through the exhaust line;

a circulation line branching from a position on the exhaust line on an upstream side in a flow direction of the exhaust gas with the carbon dioxide recovery device as a reference and connected to the gas turbine;

a first valve device provided on the circulation line;

a bypass line branching from a position on the exhaust line on a downstream side of the circulation line in the flow direction and the upstream side of the carbon dioxide recovery device, bypassing the carbon dioxide recovery device, and connected to a position on the exhaust line on a downstream side of the carbon dioxide recovery device;

a second valve device provided on the bypass line;

a third valve device provided on the exhaust line at a position between the bypass line and the carbon dioxide recovery device;

a densitometer provided on the exhaust line and configured to detect a carbon dioxide concentration in the exhaust gas; and

a control device configured to adjust opening degrees of the first valve device, the second valve device, and the third valve device based on at least one of an operation state of the gas turbine and the carbon dioxide concentration,

wherein the control device is configured to close the first valve device and the third valve device and open the second valve device until a predetermined time elapses from activation of the gas turbine.

2. The gas turbine plant according to claim 1 ,

wherein the control device is configured to, after a predetermined time has elapsed from activation of the gas turbine, adjust the opening degree of the first valve device in a direction of increasing the opening degree in a state in which the second valve device is opened and the third valve device is closed.

3. The gas turbine plant according to claim 1 ,

wherein the control device is configured to, after a predetermined time has elapsed from activation of the gas turbine, close the second valve device and open the third valve device in a case in which the carbon dioxide concentration is larger than a predetermined threshold value.

4. The gas turbine plant according to claim 1 , further comprising:

an exhaust gas compressor provided on the circulation line and configured to increase a pressure of the exhaust gas flowing through the circulation line.

5. The gas turbine plant according to claim 1 , further comprising:

an exhaust heat recovery boiler configured to generate steam by heat of the exhaust gas exhausted from the gas turbine and guide the exhaust gas passing through an inside of the exhaust heat recovery boiler itself to the exhaust line; and

an exhaust gas heater disposed on the exhaust line on the downstream side of the carbon dioxide recovery device in a flow of the exhaust gas,

wherein the exhaust gas heater is a heat exchanger configured to heat the exhaust gas by performing heat exchange between water heated by the exhaust heat recovery boiler or steam generated by the exhaust heat recovery boiler and the exhaust gas flowing through the exhaust line.

6. A gas turbine plant comprising:

a gas turbine configured to receive fuel in accordance with a required output, combust the fuel, and be driven by a combustion gas generated by combusting the fuel;

an exhaust line configured to guide an exhaust gas exhausted from the gas turbine to an outside;

a carbon dioxide recovery device provided on the exhaust line and configured to recover carbon dioxide contained in the exhaust gas flowing through the exhaust line;

a circulation line branching from a position on the exhaust line on an upstream side in a flow direction of the exhaust gas with the carbon dioxide recovery device as a reference and connected to the gas turbine;

a first valve device provided on the circulation line;

a bypass line branching from a position on the exhaust line on a downstream side of the circulation line in the flow direction and the upstream side of the carbon dioxide recovery device, bypassing the carbon dioxide recovery device, and connected to a position on the exhaust line on a downstream side of the carbon dioxide recovery device;

a second valve device provided on the bypass line;

a third valve device provided on the exhaust line at a position between the bypass line and the carbon dioxide recovery device;

a densitometer provided on the exhaust line and configured to detect a carbon dioxide concentration in the exhaust gas;

a control device configured to adjust opening degrees of the first valve device, the second valve device, and the third valve device based on at least one of an operation state of the gas turbine and the carbon dioxide concentration; and

an exhaust heat recovery boiler configured to generate steam by heat of the exhaust gas exhausted from the gas turbine and guide the exhaust gas passing through an inside of the exhaust heat recovery boiler itself to the exhaust line,

wherein the carbon dioxide recovery device includes a regeneration tower configured to regenerate an absorption liquid that absorbs the carbon dioxide in the carbon dioxide recovery device by water heated by the exhaust heat recovery boiler or the steam generated by the exhaust heat recovery boiler.

7. An exhaust carbon dioxide recovery method for a gas turbine plant including a gas turbine configured to receive fuel in accordance with a required output, combust the fuel, and be driven by a combustion gas generated by combusting the fuel, an exhaust line configured to guide an exhaust gas exhausted from the gas turbine to an outside, a carbon dioxide recovery device provided on the exhaust line and configured to recover carbon dioxide contained in the exhaust gas flowing through the exhaust line, a circulation line branching from a position on the exhaust line on an upstream side in a flow direction of the exhaust gas with the carbon dioxide recovery device as a reference and connected to the gas turbine, a first valve device provided on the circulation line, a bypass line branching from a position on the exhaust line on a downstream side of the circulation line in the flow direction and the upstream side of the carbon dioxide recovery device, bypassing the carbon dioxide recovery device, and connected to a position on the exhaust line on a downstream side of the carbon dioxide recovery device, a second valve device provided on the bypass line, a third valve device provided on the exhaust line at a position between the bypass line and the carbon dioxide recovery device, and a densitometer provided on the exhaust line and configured to detect a carbon dioxide concentration in the exhaust gas, the method comprising:

adjusting opening degrees of the first valve device, the second valve device, and the third valve device based on at least one of an operation state of the gas turbine and the carbon dioxide concentration,

wherein said adjusting operation includes:

closing the first valve device and the third valve device; and

opening the second valve device until a predetermined time elapses from activation of the gas turbine.