Lvl.2 Flashcards
What is the flame temperature of methane?
a) 1000f
b) 2500f
c) 3600f
c)
What is the calorific value of propane?
2520btu
Which gas has the lowest specific gravity (relative density)?
a) air
b) ch4
c) c3h8
d) c4h10
b)
What is the specific density of water?
1
True or False
All hydrocarbon fuel gases require approximately 10cuft of air for every 1000btuh of energy for complete combustion?
true
How many btuh is 96kw?
96 x 3414
What are the liquefied petroleum gases (LPG)?
a) butane and air
b) propane and air
c) propane and butane
d) methane and butane
c)
The expansion ratio of propane liquid to propane gas is?
a) 1:600
b) 1:270
1:270
What is the purpose of adding mercaptan to fuel gases?
Make it readily detectable in the atmsophere
Approximately how much oxygen is present in air?
a) 15%
b) 20%
c) 35%
b)
What are the lower and upper explosive limits of methane?
4% - 15%
What is the air to fuel ratio required to achieve stoichiometric combustion?
a) 1:1
b) 2:1
c) 5:1
d) 10:1
d)
How much total air is required for the complete combustion process per 1000btu’s in an atmospheric nature draft appliance?
a) 10ft3
b) 15ft3
c) 25ft3
d) 30ft3
d
Theoretically how much co2 is produced by burning 50ft3 of ch4?
a) 10ft3
b) 25ft3
c) 50ft3
c) 50ft3
How much excess air is supplied to an atmospheric burner?
a) 10% of primary air
b) 25% of primary air
c) 50% of the air required for stoichiometric combustion
c)
How much dilution air is required for an atmospheric appliance?
a) 30cuft per 1000btuh
b) 15 cut per 1000btuh
c) 10cuft per 1000btuh
b)
What is the yield formula for the stoichiometric combustion of methane?
= 1,2,8
What is the approximate percentage of the air that is supplied through the primary air openings on a premix atmospheric burner?
a) 10%
b) 20%
c) 33%
d) 80%
c)
What percentage is primary air and secondary air?
Secondary is 66%
Primary 33%
What two factors have the greatest effect on stack draft?
a) height and temperature
b) volume and temperature
c) height and volume
a)
What effect does dilution air have on the stack draft?
a) it cools the flue gases and increases the draft
b) it cools the flue gasses and decreases the draft
c) it cools the flue gases and reverses the draft
d) it has no effect
b)
The movement of warm air from a buildings interior to the outside environment is known as?
a) exfiltration
b) infiltration
c) natural draft
d) chimney effect
a)
The temperature rise in a buildings interior is caused by the sun shining through windows is called
a) conductive heat gain
b) exfiltration
c) infiltration
d) radiant heat gain
d)
Cold dense outdoor air enters through openings in the lower portion of the building, is then heated, rises, and exits through openings in the upper building is known as
a) balancing
b) infiltratrion
c) exfiltration
d) stack effect
d)
Negative pressure in a building is caused by
a) excessive removal of air
b) inward pressure on walls
c) outwards pressure on walls
a)
Minimum thickness of vapour barriers in a building is
a) 0.06”
b) 6 mil
c) 6mm
b)
Ideal relative humidity is?
a) 5%-15%
b) 15% - 35%
c) 35%-50%
c)
What is the maximum depressurization that a building with natural draft vented appliances should be exposed to?
a) 0.02 pa
b) 2pa
c) 5pa (0.02” WC)
c)