Steam turbine reaction

BLADE CLEARANCE (STEAM TURBINE) - Reaction turbine - the gap between blade and casing. Impulse turbine - the gap between the stationary and moving blades. 

In this accident, the steam was isolated from the reactor containing the unfinished batch and the agitator was switched ofiF. The steam used to heat the reactor was the exhaust from a steam turbine at 190 C but which rose to about 300°C when the plant was shutdown. The reactor walls below the liquid level fell to the same temperature as the liquid, around 160°C. The reactor walls above the liquid level remained hotter because of the high-temperature steam at shutdown (but now isolated). Heat then passed by conduction and radiation from the walls to the top layer of the stagnant liquid, which became hot enough for a runaway reaction to start (see Fig. 9.3). Once started in the upper layer, the reaction then propagated throughout the reactor. If the steam had been cooler, say, 180 C, the runaway could not have occurred. ... 

Figure 2-2. Steam turbine using reaction blading. (Source GHH-Borsig.)...

TTiere are two main types of expansion turbines axial flow and radial flow. Axial flow expansion turbines are like conventional steam turbines. They may be single-stage or multistage with impulse or reaction blading, or some combination of the two. Turbines of this type are used as power recovery turbines. They are used where flow rates, inlet temperatures, or total energy drops are very high. 

Thus, the net reaction is just Eq. 15.77. Methane-fueled MCFCs are leading candidates for local power plants in the range 1-3 MW, as their cost and efficiency are more attractive than those of PAFCs. The relatively high temperature of the exhaust gases means that they can be used effectively to drive conventional gas or steam turbines to generate additional ( topping ) electricity for increased overall efficiency. Less CO2 per kilowatt-hour is produced than by other fossil fuel-fired power generation methods, and emissions of NO , SO , and unburned hydrocarbons are minor. 

FUEL. In the conventional sense, a fuel is a material or combination of materials which, when burned with air, produces heal. This heat, in turn, can he used in numerous ways—as in the conversion of water lo steam. The steam, in turn, can be used in many ways—as in a steam turbine to produce electricity, Fuels also are burned to oblain explosive or mechanical energy—as in an internal combustion engine where heal per se is an inevitable, bul undesired byproduct. The term fuel is also used in connection with nuclear reactions—as the material, such as uranium and plutonium isotopes, which undergoes fission and. in so doing, yields heat energy, Fuel also appears in the term fuel cell, in which chemical reactions other than what may be considered as conventional combustion are carried out 10 yield electrical energy. 

From an internal design perspective, the steam turbine is either an impulse-or a reaction-type design. In the United States, almost all turbine designs are of the axial flow variety, and only a small number are of the tangential flow variety. In Europe, a significant number of turbines are of the radial flow... 

Combustion of char and gas occurs within the jet to provide the heat necessary for the endothermic devolatilization, gasification, and desulfurization chemical reactions. Extraction steam from the steam turbine is also fed to the gasifier. CO and H2 are the... 

The early history of atomic weapons and fallout left a residue of fear and distrust of nuclear technologies. The so-called anti-nuke movement developed from this residue. Civilian nuclear power plants use a controlled nuclear fission reaction to boil water to turn a steam turbine to make electricity. The corporate sector was initially reluctant to finance nuclear power plants when President Eisenhower praised them in 1953. However after Congress enacted the Price-Anderson Act in 1957, to limit corporate liability in case of mishap, development of the technology proceeded apace. The first nuclear power plant built without direct government funding went on-line in late 1959. 

The emphasis on production of pure plutonium for weapons continued throughout the Cold War period. The successful control of the chain reaction to power submarines to cruise underwater for weeks rather than hours for the diesel-electric powered substitutes opened up a new option. The contractors that built the nuclear reactors and steam turbines for submarines also served the electric power utilities. Extension of this nuclear technology to domestic electric power production was obvious. President Eisenhower s Atoms for Peace initiative in 1954 opened the way for the nuclear power plants that followed that currently supply about 20% of the electric power to the U.S. power grid. 

The neutron carries much of the energy released by this reaction. The neutrons have no electric charge so they are not contained by the magnetic field. They must be captured in a blanket material. When the blanket material absorbs them, their energy is transformed into heat. The heat from the neutrons and the radiant energy emitted from the hot plasma and directly adsorbed by the walls of the reactor are the heat output of the fusion reactor. This heat can be used to produce steam for the generation of electric power by conventional steam turbines. 

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