Читать книгу Integration of Renewable Energy Sources with Smart Grid - Группа авторов - Страница 34

1 (i) Boiler and Boiler Furnace: A boiler incorporates a furnace to burn the fossil fuel (coal, gas, waste, etc.) and generate heat/steam which is transferred to water to make steam. The types of boiler used in a thermal power plant are water tube and fire tube boiler.

2 (ii) Superheater: It is used to convert the wet steam or saturated steam in to dry steam or superheated steam. Superheated steam contains more heat than the saturated steam at the same pressure. The more heat provides more energy to the turbine hence power output is more.

3 (iii) Economizer: It is used to capture the waste heat from flue gas and transfer it to the boiler feedwater. Economizer alone can produce 10%–12% efficiency increase; thereby, it saves 5%–15% fuel consumption.

4 (iv) Condenser: It is used to convert the steam exhausted from the turbine into the water so that it can be reused again in the boiler. There are two types of condensers are used and they are jet and surface condensers.

5 (v) Feed Water Heaters: A feedwater heater is used in a conventional power plant to preheat boiler feedwater. The source of heat is steam bled from the turbines, and the objective is to improve the thermodynamic efficiency of the cycle.

6 (vi) Air Preheaters: After leaving the economizer, further heat from the flue gas is used to heat the incoming air using air preheater. Flue gas should not be cooled below the dew point to avoid corrosion of the air preheater.

7 (vii) Turbines: There are two types of turbines used:Impulse turbine: In this turbine, moving and fixed blades are used. The moving blades are mounted on the shaft and fixed blades are fixed to the casing of the turbine. Steam is passed through the fixed nozzles. The steam with high velocity comes out of the nozzle and impinges on the rotor blades.Reaction turbine: In this turbine, only fixed and moving blades are used. When high-pressure steam passes through fixed blades, then steam pressure drops down, and the velocity of steam increases.

8 (viii) Cooling towers: The cooling tower transfers the heat from the water’s heat to the air by directly or by evaporation of the water. So that water coming out of the condenser is reused.

Advantages of Thermal Power Plant

 Fuel cost is comparatively low.

 Installation requires less land compared to a hydropower plant.

 The thermal energy production mechanism is simple and easy.

 The initial cost is lesser compared to other power plants.

 Easy maintenance.

Disadvantages

 The huge production of CO2 which causes pollution.

 Overall efficiency is less than 30%.

 A huge amount of water is required.

 Warm water comes out of the thermal power plant affects aquatic life.

 Thermal engines require a huge amount of lubricating oil.