Boiler electrical generation

The hot gases from the combustor, temperature controlled to 980°C by excess air, are expanded through the gas turbine, driving the air compressor and generating electricity. Sensible heat in the gas turbine exhaust is recovered in a waste heat boiler by generating steam for additional electrical power production. 

In 1983 there were 116 flue-gas desulfurization (FGD) systems in service, representing 47 gigawatts-electric of power generation capacity (66). As of 1992, more than 150 coal-fired boilers in the United States operated with FGD systems. The total electrical generating capacity of these plants has risen to 72 gigawatts (67). FGD processes are classified into (/) wet-throwaway, (2) dry-throwaway, (J) wet-regenerative, and (4) dry-regenerative processes (68). 

Ejftciency Factors Representative efficiency data for boilers, pyrolytic reacdors, gas turbines, steam-turbine-generator combinations, electric generators, and related plant use and loss factors are... 

Boilers with an aggregate not less than 200 tons per hour of steam being used wholly or in part for electricity generation. 

Very large, modem WT boilers with sophisticated heat-recovery auxiliaries may attain efficiencies approaching 88 to 90%. However, the overall efficiency of a fossil fuel utility power generation plant system falls to only 32 to 38% when the efficiency of electricity generation and condenser cooling is included. Nevertheless, it only requires 10% more in fuel costs to operate a boiler at 1,250 psig than... 

Electricity is produced by the conversion of heat energy (produced in a boiler and transmitted as steam) into mechanical work by use of a turbine, which is connected to an electrical generator (turbine generator). 

The development of critical pressure boilers during the 1950s came in the post-World War 11 years amid a growing demand for domestic electricity consumption, especially within fully industrialized countries. The invention stimulated further designs for low-cost electricity generation. 

Utility operators may choose from several technologies to generate electricity, although the most common approach is via the use of high-temperature, fossil fuel boiler plants. In this case, the boiler (steam generator) itself may be of several different design types. 

Combined Cycle Boiler Systems These boiler types are used to harness the waste heat from one power source to provide the heat source for a second power source, usually an electricity generator via a steam turbine. They are a form of cogeneration boiler plant. 

All boiler plants providing steam for electricity generation must be provided with silica removal pretreatment equipment. Pretreatment technologies for silica reduction and removal include ... 

Heavy industrial boilers operating in continuous processes may be online for perhaps four or even five years before shutting down for maintenance and inspection. Here, correct boiler plant materials selection is critical, and the quality of the various utility support functions must be outstanding if forced outages are to be avoided. A heavy industrial or utility boiler that is unintentionally offline may cost 1 million a day in lost production or electricity generation. 

Biomass gasifiers have the potential to be up to twice as efficient as using conventional boilers to generate electricity. For even greater efficiency, heat from the gas turbine exhaust can be used to generate additional electricity with a steam cycle. These improvements in efficiency can make environmentally clean biomass energy available at costs more competitive with fossil fuels. 

Today, large amounts of biomass are already used to generate heat and electricity (mainly wood) and are predicted to increase further (e.g., wood-pellet-fuelled boilers, wood-chip-fuelled CHP plants, electricity generation from biogas). 

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