The exhaust gas heat loss of coal-fired boiler is caused by the flue gas removed by final stage heat exchanger. The flue gas will take away a part of heat, mainly including the heat taken away by dry flue gas and the sensible heat with water vapor in the flue gas. What’s more, if the combustible gas in the coal-fired boiler is not completely burned, there will be heat loss as well. Therefore, this kind of heat loss mainly depends on the content of incomplete combustion products in the exhaust smoke.
Every customer is concerned about the service life of products he purchases. Extending the service life of thermal oil heater is helpful for reducing customer’s costs and increasing profits. Different existing thermal oil heaters on the market have different service years.
Influencing factors of slagging on heating surface of boiler
(1) Ash characteristics of pulverized coal
Generally, the softening temperature ST of ash is used as the main indicator of slag formation. Coal with low ash melting point (ST<1200℃) is easy to slag. In addition, the slagging index also includes: silicon ratio, alkali-acid ratio, slagging index, limit viscosity and so on.
（2）Aerodynamic characteristics in the furnace
Improper air flow organization leads to flame center deviation, and the pulverized coal air flow flame adheres to the wall, causing local slagging of the water-cooled wall;
Improper air flow organization, forming flue gas retention vortex area and forming a reducing atmosphere (with CO), reducing the ash melting point and increasing the possibility of slagging.
Excess air coefficient: When the excess air in the furnace is too small, a reducing atmosphere may be generated, and the tendency of slagging will increase accordingly.
（3）Influence of boiler heat lo
The explosion-proof door of the gas-fired boiler is opened or broken when the combustible gas explosion suddenly increases the pressure, it then releases high-pressure gas to reduce the damage to the gas-fired boiler body and also ensure
The function of the gas-fired boiler explosion-proof door is usually reflected when the gas-fired boiler is ignited or running due to improper operation. For instance, the furnace is not purged before ignition, the furnace is still not purged even the ignition cannot successfully be lit, the nozzle is leaking, the fuel is not completely burned, and extinguished failure to cut off fuel quickly, etc. all of them may cause the furnace and tail flue to explode. Installing explosion-proof door for gas-fired boiler is to release the pressure to avoid the accident from expanding and also to ensure the safety of the industrial steam boiler when a slight explosion occurs in the furnace or flue.
A water level sensor fail on a steam boiler is extremely dangerous. The low water cut of should be tested daily. If the sensor fails the boiler could turn all the water into steam, leaving the boiler dry. Without water in the boiler the flame from the burner would heat up the heating surface to extreme temperatures and would crack and damage the inside of the boiler. But that’s not the dangerous part. If water added to boiler while it is extremely hot. Once water touches the extremely hot heating service, water would immediately start to evaporate into steam. When water evaporates it expands 18x it’s original size. The boiler would explode from the sudden increase in pressure from the inside. Some in some cases, boilers that have exploded out of a building and have landed 100s of feet away.
If the boiler burner fails or is faulty, then your boiler is not going to be able to generate heat efficiently, or in the worst case not at all . As industrial boilers are in almost constant use they are built to be very robust and last for decades, nevertheless they can still have problems with broken burners from time to time. Burner pumps, heads and nozzles can all cause problems but a swift replacement should limit your down time.
It could also say, how much heat is required to rais the water temperature from 60 ℃ to 90 ℃.
To calculate heat required follow below steps
Q= mCp dt
Where
m - water flow rate (kg/hr)
Cp- specific heat of water
dt- temperature differences ( 90–60)
You will get heat required in kcal/ hr.
dividing to Q by fuel GCV and system efficiency you will come to know how much fuel (either it is coal or oil) required to raise the temperature of water from 60 ℃ to 90℃.
If you smell gas, don’t use electrical switches, telephones, or any appliances that may cause sparks.Firstly, you should shut off the gas valve, open the doors and windows to circulate the air. Then you should seek for professional help:
