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Indicate whether the statement is true or false.
1. A wood gasification boiler is a single-stage device.
a.
True
b.
False
2. The purpose of refractory bricks in a welded-steel wood fired boiler is to protect the steel from high temperatures.
a.
True
b.
False
3. Smoke generation and increased creosote formation occurs when an outdoor wood-fired hydronic heater goes into
stand-by mode.
a.
True
b.
False
4. The same amount of chemical energy is contained in a given volume of wood, regardless of species.
a.
True
b.
False
5. Outdoor wood-fired hydronic heaters have relatively high PM2.5 particulate emissions, which represent a human health
concern.
a.
True
b.
False
Indicate the answer choice that best completes the statement or answers the question.
6. What value represents the actual amount of air supplied to the combustion process divided by the stoichiometric air
requirement?
a.
beta ratio
b.
delta ratio
c.
gamma ratio
d.
lambda ratio
7. What type of water compartment is associated with nearly all outdoor wood-fired hydronic heaters?
a.
unpressurized
b.
pressurized
c.
partially under pressure
d.
under a vacuum
8. How is heat extracted from a natural draft wood-fired boiler?
a.
mostly by release directly into the room
b.
through stainless steel tubes at the upper sides and top of the combustion chamber
c.
by radiation from the refractory bricks
d.
through a heat exchanger positioned just beneath the combustion chamber
9. Which is a primary factor in sizing a wood-gasification boiler?
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a.
the physical space available
b.
the amount of available firewood
c.
the number of firing cycles per day the owner is comfortable with
d.
the availability and location of electricity at the site
10. For what load should a pellet-fired boiler be sized?
a.
half the design load
b.
60–70 percent of the design load
c.
80–90 percent of the design load
d.
full design load
11. What type of piping is recommended when combining a wood-fired boiler with an auxiliary boiler?
a.
series
b.
parallel
c.
either series or parallel
d.
neither series or parallel
12. Why is creosote dangerous?
a.
It is difficult to clean up.
b.
It is a product of incomplete combustion.
c.
It decreases thermal efficiency.
d.
It is toxic when touched.
13. What is an example of a passive overheat protection subsystem?
a.
uninterruptible power supply
b.
fin-tube array positioned above the boiler
c.
smart controller
d.
AC powered circulator
14. What device feeds pellets into a pellet-fired boiler?
a.
day hopper
b.
auger system
c.
burn pot
d.
bag silo
15. What is the function of a variable-speed setpoint circulator?
a.
It protects a wood-fired or pellet-fired boiler from low inlet water temperature.
b.
It protects a wood-fired or pellet-fired boiler against over-pressure conditions.
c.
It senses when flue-gas condensation is occurring.
d.
It allows automatic fuel dispensing into the boiler.
16. Which statement about wood as a renewable energy source is FALSE?
a.
Wood is considered carbon-neutral
b.
Wood is a form of biomass
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c.
Wood contains energy from sunlight
d.
Wood is the least used renewable heating energy source in the U.S.
17. What is a typical temperature in the secondary combustion zone of a wood-gasification boiler?
a.
500° F
b.
1000° F
c.
2000° F
d.
4000° F
18. What is the most efficient operating condition for a wood-gasification boiler?
a.
Small amounts of cordwood are continuously replenished.
b.
Firebox full of cordwood is burned continuously.
c.
Firebox full of cordwood is burned as a batch.
d.
Firebox full of cordwood is burned halfway, then finished when there a is a concurrent heating load.
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