Fossil fuels thermal power plants

Recently, the management of large nuclear and fossil fuel thermal power plants have stimulated the development of diagnostic systems, in order to improve primary coolant quality. Such improvements constitute indirect tools for increasing the plant reliability and safety, both depending on the corrosion of the structural materials. 

A1.1 Fossil fuel thermal power plants (listed here just for reference purposes)... 

The thermal efficiency of this cycle is that of a Carnot engine, given by (5.8). As a reversible cycle, it could serve as a standard of comparison for actui steam power plants. However, severe practical difficulties attend the operatk of equipment intended to carry out steps 2 3 and 4 1. Turbines that take i saturated steam produce an exhaust with high liquid content, which causes sevel erosion problems, t Even more difficult is the design of a pump that takes in mixture of liquid and vapor (point 4) and discharges a saturated liquid (poll 1). For these reasons, an alternative model cycle is taken as the standard, at lei for fossil-fuel-buming power plants. It is called the Rankine cycle, and diSei from the cycle of Fig. 8.2 in two major respects. First, the heating step 1 2 ... 

The atmosphere is an important conveyor belt for many pollutants. The atmosphere reacts most sensitively to anthropogenic disturbance because proportionally it represents a much smaller reservoir than land and water furthermore, the residence times of many constituents of the atmosphere are smaller than those that occur in the other exchange reservoirs. Water and atmosphere are interdependent systems. Many pollutants, especially precursors of acids and photooxidants, originate directiy or indirecdy from the combustion of fossil fuels. Hydrocarbons, carbon monoxide, and nitrogen oxides released by thermal power plants and, above all by automobile engines, can produce, under the influence of sunlight, ozone and other photooxidants. 

This NH3 is used mainly to manufacture nigrogen fertilizers. Furthermore, N2 is converted into nitrogen oxides in the combustion of gasoline and fossil fuel (automobile engines and thermal power plants) ... 

Humanity s major sources of energy are derived from fossil fuels, principally oil, gas, coal, and wood. The major combustion by-products of fossil fuel burning include sulfur dioxide (SO2), carbon dioxide (CO2), and nitric oxide (NO2), and partially oxidized hydrocarbons. The process of burning fossil fuels in thermal power plants, factories, homes, and motor vehicles emits enormous amounts of the aforementioned pollutants. The most important environmental concerns resulting from fossil fuel use are global climate change, acid rain, surface ozone, and partic-ulate-Zaerosol-bound toxins. 

This shows that all these systems have already left the experimental R D stage and become an economic reality. They have already demonstrated lower consumption of natural fossil fuels per unit of power generated and lower emission of greenhouse gases and other harmful products. Other advantages over thermal power plants are associated with fuel cell-based power plants. They can be produced in modules, from which power plants of different size and output can be put together. This attribute, known as scalability, facilitates the design and construction of plants adapted to specific local requirements. 

A nuclear power plant is a thermal power plant in which heat is produced by a nuclear reactor instead of by combustion of fossil fuel. The major components of a nuclear reactor are... 

Combined-cycle thermal power plants with natural gas fuel are considered as relatively clean fossil fuel—fired plants compared with coal and oil power plants, and they are dominating new capacity additions because of lower gas production costs using liacking technology, but they still emit CO2 because of the combustion process. 

Natural gas is considered as a clean fossil fuel compared to coal and oil, but still, due to the combustion process, emits a lot of carbon dioxide when it used for electrical generation. The most efficient modem thermal power plants with thermal efficiencies within a range of 50—60% (up to 62%) are, so-called combined cycle power plants (combination of Brayton gas turbine and Rankine steam turbine power cycles) (see Figs. Al.l—A1.4, and Tables Al.l and A1.2), which use mainly natural gas as a fuel. 

---