[ PPE ] [ QUIZ 1 ]

45問 • 2年前

問題一覧

1. Steam expands adiabatically in a turbine 2000 kPa, 400°C to 400 kPa, 250°C. What is the effectiveness of 15°C. Neglect changes in kinetic energy and potential energy.

a. 79

2. In a cogeneration plant, steam enters the turbine at 4 MPa and 400°C. One fourth of the steam is extracted from the turbine at 600 KPa pressure heating. The remaining steam continues to expand to 10 KPa. The extracted steam is then condensed and mixed with feedwater at constant pressure and the mixture is pumped to the boiler pressure of 4 MPa. The mass flow rate of the steam through the boiler is 30 kg/s. Disregarding any pressure drop and heat losses in the piping, and assuming the turbine and pump to be isentropic, how much processed heat is required in KW?

d. 15647.5

3. A 23.5 kg steam per second at 5 MPa and 400°C is produced by a steam generator. The feedwater enters the economizer at 145°C and leaves at 205°C. The steam leaves the boiler drum with a quality of 98 %. The unit consumes 2.75 kg of coal per second as received having a heating value of 25102 KJ/kg. What would be the overall efficiency of the unit in percent?

c. 88

4. A Steam generating plant consisting of a boiler, an economizer and super heater generates superheated steam at the rate of 50 tons per hr. Feedwater enters the boiler at 5 MPa and 120°C. Steam leaves the supęrheater at 4.5 MPa and 320°C. If the coal used has a heating value of 30,000 KJ/kg. Calculate the no. of tons coal fired per hr for a gross efficiency of 85%.

b. 4.889 tons/hr

5. A water tube boiler has a capacity of 1000 kg/hr of steam, the factor of evaporation is 1.3, boiler rating is 200 %, boiler efficiency is 65%, heating surface area is 0.91 m^2 per bo. HP, and the heating value of fuel is 18400 kCal/kg. The total coal available in the bunker is 50000 kg. Determine the no. Of hours to consume the available fuel.

d. 853.36 hrs

6. Steam turbine is receiving 1014 Ibm/hr of steam, determine the horsepower output of the turbine if the work done by steam is 251 Btu/lbm.

a. 100 hp

7. One kilogram of wet steam at a pressure of 3 bar ( Ug = 0.2404 m³/kg, Uf = 0.0011148 m³/kg and dryness of 0.94 is expanded until the pressure is 4 bar ( Ug = 0.4625 m³/kg, Uf = 0.0010836 m³/kg). If the expansion follows the law PV^n = C, where n = 1.12, find the dryness fraction of the steam at the lower pressure.

a. 0.9072

Answer the following:

d. 104.80 KJ/kg

Answer the following:

a. 853.36 hrs

Answer the following:

a. 230.80 hrs

Answer the following:

c. air preheater

Answer the following:

a. Engine indicator

Answer the following:

d. Indicator diagram

14. The power output of the generator

d. Electrical Power

15. The amount of fuel needed to perform a unit of power

a. Specific fuel consumption

16. The ratio of heat converted to useful power to the heat supplied.

c. Thermal efficiency

17. The ratio of the actual power of the engine to its ideal power.

d. Engine efficiency

18. The ratio of the cylinder volumes after and before the combustion process.

b. Cut-off ratio

19. The position of the piston when it forms the smallest volume in the cylinder.

b. Head End Dead Center Position

20. The power developed in the engine cylinder as obtained from the pressure in the cylinder.

c. Indicated power

21. The difference between the maximum and minimum volume.

c. Clearance volume

22. What is the primary purpose of an Electric Power Substation ?

c. To switch or transform voltage levels

23. What does the term " Load " refer to in the context of electric power ?

c. The power delivered by a machine

24. Which curve represents the average of daily load curves over a one-month period and is used for rate establishment?

c. Monthly Load Curve

25. What is the " Maximum Demand " often referred to as ?

b. Peak Load

26. What is the purpose of a Load-Duration Curve ?

b. To rearrange data from a chronological load curve

27. What does " Demand Factor " measure ?

a. The ratio of connected load to maximum demand

28. What is the " Diversity Factor " in electrical systems ?

c. The ratio of individual maximum demands to simultaneous maximum demand.

29. What is " Base Load " in the context of electrical systems ?

b. The minimum load over a given period

30. What does a Load-Energy Curve indicate?

a. The total energy for a given load and all values less (greater) than that load.

31. What is " Connected Load " defined as ?

a. The sum of all connected equipment

32. What does the " Annual Load Curve " represent ?

a. The maximum demand over a year

33. What does " Load Factor " measure ?

a. The ratio of connected load to maximum demand

34. What is the " Coincidence Factor " ?

b. The reciprocal of diversity factor

35. What is the " Plant Factor " ?

b. The ratio of average load on the plant to the aggregate rating of all generating equipment.

36. What is the " Capacity Factor " defined as ?

a. The ratio of average load on a machine to its rating

37. The maximum demand on a power station is 100 MW. If the annual load factor is 40%, calculate the total energy generated in a year.

a. 3504 × 10⁵ kWh

38. A generating station has a connected load of 42 (43) and a maximum demand of 20 MW; the units generated being 61.5 × 10⁶ per annum. Calculate (i) the demand factor and (ii) load factor.

d. 0.465, 35.1 %

39. A 100 MW power station delivers 100 MW for 2 hours, 50 MW for 6 hours and is shut down for the rest of each day. It is also shut down for maintenance for 45 days each year. Calculates its annual load factor.

b. 20.8 %

40. A generating station has a maximum demand of 25 MW, a load factor of 60 % plant; a plant capacity factor of 50% and a plant use factor of 72 %. Find the reserve capacity of the plant.

c. 5 MW

41. A generating station has a maximum demand of 25 MW, a load factor of 60% a plant capacity factor of 50 % and a plant use factor of 72 % . Find the daily energy produced.

b. 360 Mwh

42. A generating station has a maximum demand of 25 MW, a load factor of 60 % a plant capacity factor of 50 % and a plant use factor of 72 %. Find the maximum energy that could be produced daily if the plant while running as per schedule, were fully loaded.

a. 500 Mwh/day

Answer the following:

b. 1.12

Answer the following;

c. 20.5 %

Answer the following:

c. 3750 kW

Machine Design ( 1st Set )

Jacky Shane Luyas Buhia · 20問 · 2年前

Machine Design ( 1st Set )