The higher heating value of natural gas refers to the total heat released when a specified amount of natural gas is completely burned, including the latent heat of vaporization released by the condensation of water vapor in flue gas into water.
The lower heating value of natural gas refers to the heat released when a specified amount of gas is completely burned, the temperature of combustion products is the same as the initial temperature of natural gas, and the generated steam remains ...
ATMOSPHERIC BOILER - a boiler in which combustion air/flue gases are drawn through the boiler without a fan. Modulating atmospheric boilers are designed to control the output (size of flame) to match the boilers variable load requirements. During this process the burner is designed to stay at the correct fuel / air ratios across the complete firing range ensuring maximum combustion and boiler efficiencies. Modulation refers to a boiler's ability to match firing rate - input - to meet the heating demand - output - of the system. (https://tlj-eng.com/news/heating-boilers-what-you-need-to-know.html)
Fully premixed low nitrogen condensing boiler refers to a boiler using fully premixed combustion technology. Fully premixed combustion refers to a combustion mode in which natural gas is fully mixed with air according to a certain proportion before combustion and air is no longer needed to be supplied during combustion.
The difference between ordinary gas-fired boiler and fully premixed low-nitrogen condensing boiler lies in whether air and natural gas are mixed before or after entering the burner.
The economizer of condensing gas-fired boiler can be installed in the flue of the current CFB boiler, to recovery the energy from the high-temperature flue gas, in order to reduce the fuel consumption. Also, the economizer helps to absorb the air pollutants such as the NOx and sulfur dioxide.
All boiler pipes have been installed and passed the hydrostatic test.
The furnace wall masonry and insulation work have all ended and has been qualified.
The flue gas duct has been installed and insulated, and the induced draft fan has been installed and debugged to be qualified and can be put into operation.
All the thermal and electrical instruments required for boiler drying have been installed and verified to be qualified.
Mortar samples have been placed on both sides of the middle par...
The advantages of boiler fueled by the methanol can be concluded as follows:
a. The emission from boiler fueled by the methanol is very environmentally friendly, without sulfur, particulate matter, heavy metals and polycyclic aromatic hydrocarbons.
b. The methanol fuel is quite cost-effective.
c. The operation of boiler fueled by the methanol is safety. Compared with compressed natural gas, liquefied petroleum gas, gasoline and diesel fuel, methanol has the char...
Ash accumulation on the heating surface.
The scaling and ash deposition on the water-cooled wall of the furnace and the ash deposition of the superheater, convention tube bundles, economizer and preheater can increase the thermal resistance of the flue gas, weaken the heat transfer, lessen the cooling effect of the flue gas and increase the exhaust gas temperature of the gas-fired boiler.
Too high excess air coefficient.
Under normal circumstances, as the furnace outlet excess...
Combustion is a process which needs constant air supply for its survival, but as we move up the earth i.e. at higher altitudes, things aren’t the same as they used to be at sea level. Due to decreased air density at higher altitude, it will consume the same volume of air but will not consume the same mass of air.
This results in less fuel consumption & less steam generation rate. Due to the reduction of mass flow of gases through tubes of a steam boiler, convective heat transf...
