What’s more, condensing occurs naturally – when the vapors cool below their dew point, which is typically
135°F.
By flowing cold water (<130°F) into the heat exchanger, AERCO boilers and water heaters automatically begin to condense to yield greater efficiencies.
How do you stop flue condensation?
Here is the bottom line: The only way to avoid sustained flue gas condensation is
to monitor the boiler’s inlet water temperature and react to that temperature by limiting the rate at which heat moves from the boiler to the distribution system
.
How is condensation formed in a flue?
Flue gas condensation is a process, where
flue gas is cooled below its water dew point and the heat released by the resulting condensation of water is recovered as low temperature heat
. Cooling of the flue gas can be performed either directly with a heat exchanger or indirectly via a condensing scrubber.
How do you get water out of flue gas?
Use
a desiccant to absorb the water
. Another method is to use a desiccant to absorb the water. Flue gas passes through a liquid spray in an absorber tower. The desiccant absorbs the water.
What is flue gas temperature?
The typical furnace outlet temperature of flue gases is usually
around 1200 °C
which will decreases gradually along the pathway of heat transfer, while the temperature of the flue gases going to stack is around 150 °C.
Why does my furnace have so much condensation?
Again, the most common reason for a leaking furnace is a condensation leak.
High-efficiency furnaces extract heat from the combustion gases for a longer period of time than a standard-efficiency furnace does
, causing the gases to cool, then condense. The condensation is routed to a floor drain.
What is the dew point of flue gas?
The acid dew point temperature depends on the levels of reactants present in the flue gas. It generally lies in the range
100-150°C.
How do you reduce the temperature of a gas flue?
The temperature of the flue gas leaving the boiler is commonly reduced in
an air preheater (APH)
when the sensible heat in the flue gas leaving the economizer is used to preheat combustion air. Preheating of combustion air has a significant positive effect on boiler efficiency.
Is flue gas corrosion?
The
corrosiveness of flue gas
is the main reason why the energy efficiency of furnaces, fired heaters and steam boilers remains poor. Flue gas originating from sulphur containing fuel becomes corrosive below a temperature of approximately 150°C (acid dew point corrosion).
What is flue gas in boiler?
Flue gas (sometimes called exhaust gas or stack gas) is
the gas that emanates from combustion plants
and which contains the reaction products of fuel and combustion air and residual substances such as particulate matter (dust), sulfur oxides, nitrogen oxides, and carbon monoxide (Table 3.7).
What is the main reason for not reducing the temperature of boiler flue gas below 120 C?
Usually we consider cooling up to the ambient temperature unless there are technical limitations; for example flue gases from diesel industrial boilers are not cooled below 120°C for
avoiding condensation of water vapor and the production of sulfuric acid
[2] . …
Why condensate steam is recirculated to boiler?
At the end of a steam power cycle,
the steam is condensed to water
. A condensate pump moves the water through LP heaters back towards another pass-through deaerator and boiler. All centrifugal pumps have a minimum flow rate through to pump to avoid overheating and cavitation.
What is the ideal CO2 content of flue gas?
Carbon dioxide – CO
2
– is a combustion product and the content of CO
2
in a flue gas is an important indication of the combustion efficiency. Optimal content of carbon dioxide CO
2
after combustion is approximately 10% for natural gas and
approximately 13% for lighter oils
.
What is the difference between dry flue gas loss and wet flue gas loss?
The dry flue gas loss accounts for the heat lost up the stack in the “dry” products of combustion, that is, CO2, O2, N2, CO and SO2. These carry away only
sensible heat
, whereas the “wet” products, mainly moisture from the combustion of hydrogen, carry away both latent and sensible heat.
How do you calculate flue gas?
Total amount of dry flue gas per 1 kg wood = 4.872 m3. Therefore % CO2 = 0.97/4.872 = 19.91 assuming stoichiometric combustion (0 % O2). For 20 % excess air = 16.6 % CO2 For 40 % excess air = 14.2 % CO2 For 50 % excess air = 13.27.
