Steam supply power generation

The envelope defined by A, B, C, and D in Fig. 6.70 represents the most thermally optimized use of a gas turbine in a cogeneration application (i.e., provides the lowest FCP). Operation along the line CE, DF, or any intermediate point to the left of line CD represents the nse of condensing steam turbine power generation with the E and F points appUcable for combined-cycle operation without any heat supplied to process.Thus, the cycles along line EF are combined cycles providing power alone. 

The HTR-PM shown in Fig. 3.9 contains two parallel trains of nuclear steam supply system (NSSS) of identical design, each consisting of a 250-MWth pebble bed reactor and a steam generator. The two NSSS systems have independent primary loops but share auxiliary facilities, such as fuel handling system and helium purification system. The two trains jointly supply superheated steam to a common steam turbine power generator rated at 200 MWg. 

Figure 4-70 shows a four-body TPG train (string). As before, the expander supplies power to the generator. The steam turbine supplies power to the generator, provides startup power, and provides control for synchronization. The generator provides electricity, and the gear is used to allow the expander and steam turbine to operate at near optimum efficiency with the generator at its desired speed. 

The DOE N-Reactor is one of the plutonium production reactors located on the Hanford Reservation near Richland, Washington. It is graphite moderated, pressurized water reactors that in addition to production of special nuclear materials also provided steam to turbine generators owned by the Washington Public Power Supply System for electric power production. It began op ition in 1 is put into standby status in 1988 and closed because of similarities to Chernobyl. 

While this basic definition of cogeneration efficiency seems straightforward, complications are created by the process steam generated from waste heat recovery that can be used for power generation or process heating and that does not require any fuel to be fired in the utility system. The heat supply can be defined as the sum of the heat from fuel (both in the utility boilers and fired heaters) and steam generation from the waste heat recovery (see Figure 23.44)17 ... 

The first commercial power plant to burn cattle manure to generate electricity was established in the Imperial Valley of southern California in 1987. The plant had a capacity of about 17 megawatts and supplied electricity to 20,000 homes. The manure is burned to produce steam for the generator. 

Solid Oxide Electrolysers (SOE) are in development for steam electrolysis. As electrolysis is an endothermic process, a supply of waste heat can be used beneficially to reduce the electrolyzer voltage, and thus increase its electrical efficiency. Combination with nuclear power generation and geothermal heat sources is often encountered in development programs for SOE. 

Figure 5.5a depicts a combined plant in which a closed Brayton helium nuclear plant releases heat to a recovery steam generator, which supplies heat to a Rankine steam plant. The generator is provided with a gas burner for supplementary additional heat when the demand of steam power is high. The Rankine plant is a regenerative cycle. 

The process at Three Mile Island involved nuclear fission and subsequent reactor cooling using circulating water. The primary water was kept under pressure to prevent boiling. Heat was transferred to a secondary water system that supplied power to a steam generator. Upon completion of this step, steam condensate was recovered and recycled. All radioactive materials, including primary water, were enclosed in a lined concrete containment building to prevent their escape to the atmosphere. 

James Watt s steam engine (around 1785) working with several bar steam pressure only, innovated the world s energy supply and induced an industrial revolution. This steam engine represented one of earliest high pressure processes for power generation. 

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