Thermal power plant

[1] 

[2] To copy paste into another document for flashcard

• TPPs use what turbines? - steam turbine

• thermal powerplants (TPPs) derive motion from its heart, what is it called? - steam turbine

• how termal powerplant generate high pressure? - loop system powered by feedewater pump and high heat

• TPPs use what turbines? - compressor

• why must TPPs bring low pressure and low temp to original state? - to maximize thermodynamic efficiency (Rankine cycle) via high vacuum forcing turbine to spin faster and allow plant to use less energy to compress fluid back to boiler

• what do compressors do? - increase gas pressure by reduce/compress volume

• why powerplant use pumps IO compressors? -

• what makes compressor inefficient in TPPs? - as compessing steam is too energy intensive

• it’s easier for TPPs to perform Rankine cycle is by converting? - steam to liquid and boost pressure

• condensor heat exchanger does? - cools hot gas/vapor, force it to become liquid

• where are condensor heat exchanger often located in TPPs? - below/undeground low pressure turbine

• what does TPP’s condensor does with cold water flowing to it? - its steam rejcts water’s heat, making it condensed, turning it into condensed working fluid

• TPPs’ feedwater is? - purified demineralized water pumped to steam generating boiler to compelte Rankine cycle

• TPPs’ multistages traffical pumping does? - brings feed water back to original state

• demineralized water means? - to remove essential minerals (calcium/mineral salts)

• describe me Rankine cycle?

  • high pressure pump forces feedwater to boiler, consuming min energy

  • high heat from fuel boils pressurized water, turning it to high pressure heated steam

  • steam expands through turbine, forcing it to spin generator make electricity

  • exhausted low pressure steam cooled back down to liquid for loop to repeat

• how TPP brings back feedwater to original temp/pressure? - “water tube” boiler which has pulverized coal boiled in i

• TPP’s boiler’s economizer does? - heat exchanger in boiler preheating for feedwater

• where does flue gas flows down into in TPP and what happens to it? - through down-comer then water wall where it becomes steam

• what separates pure steam in TPP? - at steam drum which finally converts steam back to original high temp and pressure state

• how can TPPs increase efficiency and capacity?

  • super heating: after liquid convert to steam, more heat added, becoming super heat (hotter steam = more efficient cycle, as stated by Carnot’s theorem)

  • reheating: as heat’s temp decrease as it flows along TPP’s blades, so more heat added after 1st turbine station to create higher power output and efficiency

  • feed-water: as PTT’s low pressure size suck external air, dissolved gas in feed water spoil boiler material, so open-heater water (OFW) heater remove dissolved gases by receiving hot steam from turbine in its feedwater and steam bubble generate to absorb dissolved gases and preheat the water

• Why is TPP’s superheated conversion limited? - its material wont sustain high tem

• Define Carnot’s theorem - no heat engine operates between 2 theraml reservoirs can be more efficient than reversible (Carnot) heat engine operating between same 2 temps

• heat rejection done is? - to remove excess thermal energy from working fluid to be condensed back to liquid

• how heat rejection done in TPPs?

  • cold liquid supplied by condenser by cooling towers ⟶ water heat up at condensor ⟶ sprayed into cooling tower that induce natural air draft ⟶ spray water lose heat ⟶ sent back to condensor

• cold water is better for condensor or high temp steam? - condensor

• hot water is better for condensor or high temp steam? - high temp steam

References

• [1] Wikipedia

• [2] How does a Thermal power plant work? - Sabin Civil Engineering (YouTube)