How do you reduce the temperature of a gas flue?
Table of Contents
- 1 How do you reduce the temperature of a gas flue?
- 2 What causes high flue gas temperature?
- 3 What is the relationship between flue gas temperature and furnace output efficiency?
- 4 Why must flue gas temperatures in conventional furnaces be kept high?
- 5 What is the temperature of gas furnace exhaust?
- 6 How do you install a flue thermometer?
- 7 How much sensible heat can be recovered from flue gas?
- 8 Why is the efficiency of a boiler low at 100 degrees?
How do you reduce the temperature of a gas flue?
Inlet air heaters are commonly used, to both heat incoming combustion air, and to reduce flue temps and thus the required size of an induced draft fan.
What causes high flue gas temperature?
The most common cause of high stack temperatures is running with too much excess air. This positive benefit is the result of increasing the percentage of carbon dioxide (CO2), and water vapor (H2O) in the flue gas as the amount of air is lowered.
How do I lower the temperature on my boiler stack?
15 Ways To Increase Boiler Efficiency
- Increase Boiler Efficiency: Lower the Stack Temperature.
- Install an Economizer.
- Tune the Burner Regularly.
- Install a Variable Frequency Drive.
- Increase Boiler Efficiency: Insulate your Valves.
- Clean the Fireside.
- Preheat Combustion Air.
- Clean the Water Side.
How is flue temperature measured?
Get a magnetic thermometer and run a screw through the hole in the middle. And btw 150 to 200 is pretty low for the outside of single wall pipe if that is accurate. Chances are you are dropping below 212 by the time it reaves the top of the chimney. 600 is to high for the surface of singlewall.
What is the relationship between flue gas temperature and furnace output efficiency?
On well-designed natural gas-fired systems, an excess air level of 10\% is attainable. An often-stated rule of thumb is that boiler efficiency can be increased by 1\% for each 15\% reduction in excess air or 40°F reduction in stack gas temperature.
Why must flue gas temperatures in conventional furnaces be kept high?
The answer is REDUCING TEMPERATURE RISE AND CONDENSING FLUE GASES. High-efficiency furnaces condense exhaust gases and reduce the temperature rise across the heat exchanger.
What is the most efficient temperature to keep the boiler at?
As a rule, setting your heating control to 75 degrees should be sufficient to give you a perfectly warm house, while also allowing your boiler to run as economically as possible. Once this is set, you shouldn’t need to adjust it.
What is boiler stack temperature?
“Stack temperature” or flue gas temperature measures the temperature of the combustion gases when they leave the boiler. If the flue gas temperature is high, it suggests the heat created by the boiler isn’t being effectively used to generate steam. These methods are designed to recover heat for the boiler system.
What is the temperature of gas furnace exhaust?
Exhaust and outlet temperatures fuels like natural gas, liquefied petroleum, diesel and more.
| Appliance type | Exhaust Temperature | |
|---|---|---|
| (oF) | (oC) | |
| Gas-fired heating appliance, no draft hood | 460 | 238 |
| Glass melting furnace | 1200 – 1600 | 650 – 870 |
| Oil-fired heating appliance, residential | 560 | 293 |
How do you install a flue thermometer?
To install a probe thermometer, drill a 1⁄4 inch hole in the outer wall, and a 3⁄16 inch hole through the inner wall. Position so the thermometer can be read easily at a glance. Slide the magnet then the eyelet onto the stem of the thermometer; and insert into the hole.
What is the typical furnace outlet temperature of flue gases?
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. Pollution control technologies can remove the SOx, NOx and particulate matter effectively,…
What is waste gas loss in a furnace?
Waste-gas loss, also known as flue gas or stack loss, is made up of the heat that cannot be removed from the combustion gases inside the furnace. The reason is heat flows from the higher temperature source to the lower temperature heat receiver. In effect, the heat stream has hit bottom.
How much sensible heat can be recovered from flue gas?
As the flue gas temperature is reduced, the amount of available sensible heat increases. The sensible heat that could be recovered from the flue gas by cooling it in a flue gas cooler (FGC) from the APH gas outlet temperature of 310F to the FGD inlet temperature of 140F is 43 to 46 Btu per pound of flue gas (depending on the coal type).
Why is the efficiency of a boiler low at 100 degrees?
Unfortunately this is somewhat high as a flue gas exit temperature and unless further heat is extracted will result in too low a boiler efficiency. Sulphur compounds, NO x and NH 4 react together in the presence of a powerful electron beam at about 100°C.