2.If NOx in a natural gas fired packaged boiler is 50 ppmvd(3 % oxygen dry),what is it in lb/MM Btu(HHV)?

0.06

0.10

0.20

3.1 in wc additional gas pressure drop in a 100,000 lb/h package boiler is worth about how many kw of fan power consumption?

5

20

50

4.If boiler water concentration in a boiler drum is 1000 ppm and steam purity is 1 ppm,what is the % steam quality?

99.9%

99%

99.99%

5.If sulfuric acid dew point of flue gases in a boiler economizer is computed at 250 F,what should be the minimum feed water temperature in F,assuming minimum gas temperature is 400 F?

300

200

245

6.If % volume oxygen (dry) in a natural gas fired boiler is 2.0 %,what is the approximate excess air % used?

15%

5%

10%

7.In a boiler plant if the conductivity of the make up water,condensate returns and feed water are 800,40 and 150 microohms/cm respectively,what is the % condensate returns in the feed water?

5%

50%

15%

8.A 20 F change in exit gas temperature in an oil fired boiler changes boiler efficiency by about what %?

1.0%

0.5%

2.0%

9.Approximate air flow (acfm) required in a package boiler firing 100 MM Btu/h(HHV) natural gas is:

19000

30000

15000

10.The steam pressure drop in a boiler superheater is 50 psi when boiler generates 600 psig,650 F steam.What is it likely to be at 400 psig,600 F with the same steam flow?

70

30

50

11.If the casing heat loss in a boiler is 0.5 % at 100 % load,what is it at 25 % load?(ambient conditions unchanged):

1.0%

2.0%

0.1%

12.The maximum possible fuel(nat gas/oil) input in MM Btu/h(LHV) to a gas turbine HRSG with exhaust flow=200,000 lb/h and with 14 % oxygen by volume is:

100

150

50

13.If CO emissions in a package boiler firing # 2 oil is 0.1 lb/MM Btu(HHV),what is it in ppmvd-3 % oxygen dry?

100

129

150

14.If the tube inner diameter of a superheater or economizer changes from 1.7 to 1.5 in(flow conditions unchanged),the pressure drop will go up by what %?

87

65

25

15.If 100 MM Btu/h (LHV) is fired in a HRSG burner,the enrgy absorbed by steam in MM Btu/h is:

100

83

92

16.A boiler fan just meets capacity at 50 F.At which of the following ambient temperatures will it have problem meeting capacity?

15

45

65

17.A smaller diameter tube generally has a tube side heat transfer coefficient compared to larger diameter tubes for the same fluid velocity

true

false

18.Heat Transfer coefficient in a finned tube surface is higher than in a bare tube exchanger for the same gas velocity,temperature,tube size and geometry

true

false

19.Exit gas temperature from the economizer in a single pressure HRSG increases as the steam generation increases:

true

false

20.Superheated steam temperature in a steam generator will be generally higher when firing oil than on gas firing(at the same load):

true

false

Note:Please do not skip any question. Any all questions even if you are not sure.Thanks.