A method for improving effectiveness of a steam generator system includes providing air to an air preheater in excess of that required for combustion of fuel and providing the air at a mass flow such that the air preheater has a cold end metal temperature that is no less than a water dew point temperature in the air preheater and such that the cold end metal temperature is less than a sulfuric acid dew point temperature. The method includes mitigating SO.sub.3 in the flue gas which is discharged directly from the air preheater to a particulate removal system and then directly into a flue gas desulfurization system. Flue gas reheat air is fed from the air preheater to heat the flue gas prior to entering a discharge stack to raise the temperature of the flue gas to mitigate visible plume exiting and to mitigate corrosion in the discharge stack.

A method for flushing a heat recovery steam generator in a power plant having a gas turbine, having a compressor, a combustion chamber and a turbine with a rotor, and having a generator coupled to the gas turbine and a start-up converter to convert from an alternating current of random frequency into an alternating current of a specified frequency. The start-up converter is connected to an output of the generator at which the alternating current of random frequency is applied. Wherein, when the gas turbine is run down, the rotor is cushioned with the help of the start-up converter at a boiler flushing speed and the heat recovery steam generator is further flushed until the specifications for flushing the waste heat steam generator are complied with.

In some aspects, a computer-implemented method of reducing a rate of fouling in a recovery boiler system is provided. A computing device receives boiler operating information for a period of time. The boiler operating information includes boiler operating parameters and a rate of fouling for the period of time. The boiler operating parameters include one or more boiler input parameters. The computing device performs a regression analysis to determine at least one correlation between the boiler operating parameters and the rate of fouling. The computing device causes at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling. In some aspects, a system configured to perform such a method is provided. In some aspects, a computer-readable medium having instructions stored thereon that cause a computing device to perform such a method is provided.

A combustion system with surface-less heat energy exchange for efficient heat energy capture and lower pollutant emission, comprising: a first line feeding an oxygen-rich reactive; a second line feeding a hydrogen fuel; a vessel containing feed-water, a combustion enclosure without a bottom wall submersed into the feed water contained in a vessel, the combustion enclosure configured to receive the feed from each of the first and second line and combust a mixture of the two feeds in a pocket formed between an inner top and side walls of the combustion enclosure and a top surface of the feed-water contained in the vessel; and the combustion within the pocket yielding a high temperature and pressure combustion product and by-product directly into the feed-water of the vessel.

A method and an arrangement for recovering heat from flue gas of a boiler (10). The method comprises passing the flue gas (G) of the boiler though a flue gas cooling unit (1), cooling the flue gas (G) by transferring heat from the flue gas (G) into a circulation (3) of a flue gas cooling liquid (CL), transferring heat energy of said flue gas cooling liquid (CL) into a heat pump (2), and arranging the heat pump (2) for receiving heat energy also from a circulation arrangement (8) of a district cooling system. The heat pump (2) is coupled to a circulation arrangement (6) of a district heating system, wherein the method further comprises transferring in the heat pump (2) heat energy (H) received from said cooling liquid (CL) and from said circulation arrangement (8) of district cooling system into said circulation arrangement (6) of district heating system, for lowering the temperature of said flue gas cooling liquid (CL) and cooling fluid of said district cooling system, and raising the temperature of heating fluid of said district heating system.

In some aspects, a computer-implemented method of reducing a rate of fouling in a recovery boiler system is provided. A computing device receives boiler operating information for a period of time. The boiler operating information includes boiler operating parameters and a rate of fouling for the period of time. The boiler operating parameters include one or more boiler input parameters. The computing device performs a regression analysis to determine at least one correlation between the boiler operating parameters and the rate of fouling. The computing device causes at least one boiler input parameter to be adjusted based on the at least one correlation to minimize the rate of fouling. In some aspects, a system configured to perform such a method is provided. In some aspects, a computer-readable medium having instructions stored thereon that cause a computing device to perform such a method is provided.

A combustion system with surface-less heat energy exchange for efficient heat energy capture and lower pollutant emission, comprising: a first line feeding an oxygen-rich reactive; a second line feeding a hydro-carbon fuel; a vessel containing feed-water; a combustion enclosure without a bottom wall submersed into the feed water contained in a vessel, the combustion enclosure configured to receive the feed from each of the first and second line and combust a mixture of the two feeds in a pocket formed between an inner top and side walls of the combustion enclosure and a top surface of the feed-water contained in the vessel; and the combustion within the pocket yielding a high temperature and high pressure combustion product and by-product directly into the feed-water of the vessel.

A method for improving effectiveness of a steam generator system includes providing a steam generator system including a steam generator vessel, an air supply system and an air preheater. The air supply system is in communication with the steam generator vessel through the air preheater and the steam generator vessel is in communication with the air preheater. The air supply system provides a first amount of air to the air preheater. At least a portion of the first amount of air is provided to the steam generator vessel. A flue gas mixture is discharged from the steam generator vessel. At least a portion of the flue gas mixture flows into the air preheater. SO.sub.3 in the flue gas mixture is mitigated before the flue gas mixture enters the air preheater.

A combustion system with surface-less heat energy exchange for efficient heat energy capture and lower pollutant emission, comprising: a first line feeding an oxygen-rich reactive; a second line feeding a hydrogen fuel; a vessel containing feed-water, a combustion enclosure without a bottom wall submersed into the feed water contained in a vessel, the combustion enclosure configured to receive the feed from each of the first and second line and combust a mixture of the two feeds in a pocket formed between an inner top and side walls of the combustion enclosure and a top surface of the feed-water contained in the vessel; and the combustion within the pocket yielding a high temperature and pressure combustion product and by-product directly into the feed-water of the vessel.

A combustion system with surface-less heat energy exchange for efficient heat energy capture and lower pollutant emission, comprising: a first line feeding an oxygen-rich reactive; a second line feeding a hydro-carbon fuel; a vessel containing feed-water;

a combustion enclosure without a bottom wall submersed into the feed water contained in a vessel, the combustion enclosure configured to receive the feed from each of the first and second line and combust a mixture of the two feeds in a pocket formed between an inner top and side walls of the combustion enclosure and a top surface of the feed-water contained in the vessel; and the combustion within the pocket yielding a high temperature and pressure combustion product and by-product directly into the feed-water of the vessel.