Boiler apparatus

A boiler apparatus that is installed in a power-generating plant and generates combustion gas from fuel and combustion air, the power-generating plant including an absorption tower allowing absorbing liquid to absorb carbon dioxide in exhaust gas, a regeneration tower separating carbon dioxide from the absorbing liquid having absorbed carbon dioxide in the absorption tower, and a steam turbine system, the boiler apparatus comprising:

• an economizer allowing water and combustion gas to undergo heat exchange to preheat the water serving as working fluid of the steam turbine system;
• an air preheater installed downstream of the economizer and allowing combustion air and combustion gas to undergo heat exchange to heat the combustion air;
• an evaporator installed downstream of the economizer and allowing water, utilized in the steam turbine system as working fluid, and combustion gas to undergo heat exchange to generate water vapor;
• an evaporator drum bringing the water vapor from the evaporator and water into contact with each other to generate saturated water vapor;
• a steam pipe connected to the evaporator drum and adapted to receive the saturated water vapor, passed therethrough, from the evaporator drum;
• a reboiler allowing the saturated water vapor from the steam pipe and the absorbing liquid from the regeneration tower to undergo heat exchange to evaporate the absorbing liquid;
• a steam bypass pipe connected to the steam pipe and allowing steam in the steam pipe to flow into a condenser in the steam turbine system;
• a valve installed in the steam bypass pipe for opening and blocking flow of the saturated water vapor in the steam bypass pipe;
• an exhaust gas pipe adapted to receive exhaust gas, passed therethrough, having passed through the air preheater, the exhaust gas pipe being connected to the absorption tower;
• an exhaust gas bypass pipe connected to the exhaust gas pipe;
• and
• a valve installed in the exhaust gas bypass pipe for opening and blocking flow of the exhaust gas in the exhaust gas bypass pipe.

A power-generating plant comprising:

• a steam turbine;
• a boiler adapted to allow water and combustion gas to undergo heat exchange to generate water vapor driving the steam turbine;
• absorption equipment adapted to allow absorbing liquid to absorb carbon dioxide in exhaust gas from the boiler;
• regeneration equipment separating carbon dioxide from the absorbing liquid having absorbed carbon dioxide in the absorption equipment;
• an economizer installed in the boiler and allowing water and combustion gas to undergo heat exchange to preheat the water serving as working fluid of the steam turbine;
• an air preheater installed downstream of the economizer in the boiler and allowing combustion air and combustion gas to undergo heat exchange to heat the combustion air;
• a first steam generator, installed downstream of the economizer in the boiler, for allowing water, utilized in the steam turbine system as working fluid, and combustion gas to undergo heat exchange to generate saturated water vapor;
• a second steam generator for allowing the saturated water vapor from the first steam generator and absorbing liquid from the regeneration equipment to undergo heat exchange to evaporate the absorbing liquid;
• a steam pipe allowing the first steam generator and the second steam generator to connect with each other;
• a steam bypass pipe connected to the steam pipe and allowing steam in the steam pipe to flow into a condenser in the steam turbine system;
• a valve, installed in the steam bypass pipe, for opening and blocking flow of the saturated water vapor in the steam bypass pipe;
• an exhaust gas pipe allowing the air preheater and the absorption equipment to connect with each other;
• an exhaust gas bypass pipe connected to the exhaust gas pipe;
• and
• a valve, installed in the exhaust gas bypass pipe, for opening and blocking flow of the exhaust gas in the exhaust gas bypass pipe.