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Energy Engineering

Subject : engineering
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Critical pressure (218 psi) and above - 38-39% efficient - supercritical from 45-47% efficient - materials limit max temp to 600 degC - pressure ratios up to 10 -000 because condenser reaches really low pressures






2. Bituminous coals are in the _____ - subbituminous coals in most of the west (but not Utah) - and lignites primarily in Texas and North Dakota.






3. Coal contributes to essentially every criteria air pollutant and to CO2 and Hg. In most cases (except CO) - coal is a major contributor.






4. Drilling - then set up production wells with nothing above surface - production decreases exponentially with time






5. From inlet temperatures with cooling of blades and thermal barrier couplings






6. Inlet/intake - compression - expansion/combustion/power - exhaust






7. Many decades and up to 100 yrs left reserves increasing due to fracking and tight gas recovery almost always seen with oil and frequently without






8. Less CO2 and most other pollutants than other combustion fuels






9. Low sulfur vs. high sulfur - bituminous used to provide most power - but switching to cleaner Wyoming subbituminous






10. Fracture rock with water and other stuff - replace with sand - suck out liberated NG






11. Higher than compression ratio in diesel or gasoline engines (note that pressure ratio is not exactly the same as a compression ratio).






12. 100 bar inside pipelines (1/600 of normal volume) - pumping stations every 40 to 100 mi - pipelines maintained and made sure safe by pigs(devices that measure stuff to make sure nothing's wrong) distribution pipelines are lower pressure and plastic






13. Coal rank correlates with both hydrogen:carbon and oxygen:carbon ratio - with rank decreasing with increasing values of both ratio. ex. anthracite low ratios and lignites have high ratios






14. Good alternative to petroleum based fuels?






15. Occurs (with a few exceptions) in the intake manifold prior to the air entering the cylinder. Air entering cylinder is a mixture of air and vaporized fuel.






16. Compressor stator (trailing edge points axially) - turbine stator (trailing edge has significant tangential component).






17. Less efficient than either Otto or Diesel cycle at same pressure ratio/compression ratio - but in practice pressure ratio is higher leading to higher efficiencies.






18. Much lower energy density than gasoline and can be corrosive or damaging to engines and seals. Because it requires less oxygen to burn - it has slightly better engine efficiency. However - its lower energy density means a car gets considerably lower






19. Have broader range of fuels - have higher compression ratios - nearly always super/turbo charged






20. Constant pressure combustion - isentropic and adiabatic compression and expansion






21. Little more than half=fuel cost - rest is transportation and distribution






22. Anthracites - bituminous coals - subbituminous coals - lignites.






23. Measures the ability of a fuel to pressure ignite and in this regard is the opposite of the octane number.






24. Same as Brayton cycle






25. your engine is knocking (igniting the gas too early when piston coming up instead of while at top) - High compression engines need higher octane fuels.






26. Not very common - small particulate and SO2 and some NOx are problems for this cycle with coal






27. Cetane numbers greater than ___ generally have no advantage over a fuel of 50. Common cetane numbers are 40-45 and 45-50 for regular and premium diesel fuels.






28. Hard=bituminous - Brown=subbituminous/lignite






29. Constant volume combustion - isentropic and adiabatic compression and expansion - 2 stroke and 4 stroke engines use (gasoline engines)






30. Modern only output CO2 and no significant impact on other pollutants - Most Coal Power are old and many have significant impact on air pollution






31. Subbituminous much bigger because produce reflective ash






32. 2 stroke and 4 stroke - Combustion rate limited by gas - phase kinetics and is very rapid.






33. Combustion rate mostly limited by heat and mass transfer rather than kinetics and is therefore much slower than in a gasoline engine - hence the constant pressure assumption - No spark plug required - glow plugs only provide local warming of system f






34. Distillate fraction (heavier than naptha) - though it requires some additional treatment for sulfur removal -






35. Fuel is injected in cylinder at much higher pressures than gasoline fuel injection and through injectors designed to atomize fuel to small droplets that rapidly vaporize and burn.






36. Steam Turbines (Rankine Cycle) - Gas Turbines (Brayton Cycle) - Combined Cycle (not very economically feasible) - Liquid Fuels and Other products (chemicals - Fischer Tropsh - Coal to Methanol for gasoline but less history)






37. Coal- fired power generation costs are roughly 50% capital and the remaining fuel and operating costs. Fuel costs have remained stable and low historically - making coal an attractive investment for power






38. Hg - As - trace other metals - no dioxins and furans






39. Measure of a fuels ability to resist compression ignition - with iso- octane having an octane number of 100 and n - heptane an octane number of 0. (n - octane has an octane number of -10).






40. 150 yrs






41. Fischer Tropsh synthesis






42. Brayton cycle with exhaust powering a Rankine Cycle (efficiencies of up to 60%) - possibly most economical choice - can't respond to load changes as rapidly as simple cycle






43. Are turbofans - which derive >80% of their thrust from the ducted fan rather than the high- velocity exhaust. Turbopros and other turbine- based engines also common for helicopters - ships - propeller- based aircraft - etc.






44. Contains an odorant - deliberately added so leaks will be noticed






45. China - and rapidly growing - India also rapdily growing






46. Brayton Cycle






47. Mid 80s






48. Methane (70-90%) - heavier hydrocarbons (up to 20% through C4) - CO2 (up to 8% - but occasionally much higher) - H2O (usually saturated) - sometimes H2S (up to 5%) - oxygen (< 0.2%) nitrogen (up to 5%) - and other trace quantities.






49. Is dominantly CH4 - but the ethane content is always >1 % and important to the fuel






50. Almost zero aromatics in it