Thermal plant electricity generation

Fig. 6. In a binary electricity generation plant, the hydrothermal water from the weU, A, is passed through a heat exchanger, B, where its thermal energy is transferred to a second, more volatile working fluid. The second fluid is vaporized and deflvered to a turbine, D. After exiting the turbine the spent working fluid is cooled and recondensed in another heat exchanger, E, using water or air as the coolant, F. It is then fed back to the primary heat exchanger to repeat the cycle. Waste hydrothermal fluid, C, can be reinjected into the producing field.

Modifications of the existing plants to sequestrate and dispose of the CO2 will lead to a reduction in net thermal efficiency and an increase in capital cost both these features will lead to increased cost of electricity generation. Whether these plants will be economic in comparison with conventional plants of higher efficiency and less capital cost will be determined by how much the conventional plants will have to pay in terms of a carbon tax. 

Thermal power plant is more commonly associated with very large central power stations. The capital cost for thermal power plant, in terms of cost per installed kilowatt of electrical generating capacity, rises sharply for outputs of less than some 15 MW. It is for this reason that thermal power plant is not usually considered for industrial applications unless it is the combined cycle or combined heat and power modes. However, for cases where the fuel is of very low cost (for example, a waste product from a process such as wood waste), then the thermal power plant, depending on output, can offer an excellent choice, as its higher initial capital cost can be offset against lower running costs. This section introduces the thermal power cycle for electrical generation only. 

Stationary power is the most mature application for fuel cells. Stationary fuel cell units are used for backup power, power for remote locations, stand-alone power plants for towns and cities, distributed generation for buildings, and cogeneration where excess thermal energy from electricity generation is used for heat. 

A conventional power plant fired by fossil fuels converts the chemical energy of combustion of the fuel first to heat, which is used to raise steam, which in turn is used to drive the turbines that turn the electrical generators. Quite apart from the mechanical and thermal energy losses in this sequence, the maximum thermodynamic efficiency e for any heat engine is limited by the relative temperatures of the heat source (That) and heat sink (Tcoid) ... 

A solar thermal electric-generation unit. A pipe containing synthetic oil is positioned along a mirror-coated trough. Sunlight hitting the mirror is reflected onto the pipe and heats the oil to 370°C. The hot oil is then pumped out and used to convert water to steam in a turbine in an electric power plant. 

Avoidance of Thermal Pollution by Using) Dry Type Cooling Towers for Steam Electric Generating Plants... 

---