To guarantee the successful and efficient shell boiler operation, the user must:
1)Know the conditions, environment, and demand characteristics of the plant, and accurately specify these conditions to the boiler manufacturer.
2)Provide a boiler house layout and installation that promotes good operation and maintenance.
3)Select the control systems that allow the boiler to operate safely and efficiently.
4)Select the control systems that will support the boiler in supplying dry steam to the plant at the required pressure(s) and flowrate(s).
5)Identify the fuel to be used and, if necessary, where and how the fuel reserve is to be safely stored.
According to the differences in fuel and structure, industrial thermal oil heaters are mainly divided into the oil/gas-fired thermal oil heater and coal/biomass-fired thermal oil heater. The basic configurations of the thermal oil boiler system generally are as follows.
The fuel of a gas-fired boiler is gas such as natural gas, city gas, biogas and liquefied gas, etc. What kind of fuel the boiler burns is decided by an equipment called a burner. The boiler equipped with a gas-fired burner is called a gas-fired boiler. There are three methods of gas-fired boiler combustion as per technical characteristics of how the gas and air mix.
1. Diffusion combustion:
Gas and air mutually diffuse at the gas nozzle and are burning. The advantages are burning stably and with simple burner structure. However, the heated area is easy to be carbonized due to long flame, which is easy to produce incomplete combustion.
2. Premixed combustion:
A part of air and gas are premixed before combustion (coefficient of primary air surplus is between 0.2-0.8), and then being burned. The advantages are clear combustion flame, enhanced combustion, and high thermal efficiency.
The causes of coal erosion as distinct from all the other types of erosion are many but from a theoretical point of view are simply high velocity particles impacting and rubbing along the surface of the tubes.
The boiler designer minimises this by providing a volume in the furnace and a direction of travel of the coal such that it is burned before it can touch the tubes. This can be defeated by increasing the velocity reducing the combustibility or increasing the mass flow. All of these parameters occur if you reduce the calorific value of the fuel or overload the boiler. If you had no erosion before changing your fuel that is the cause. If you have never had design fuel you dont know if it would have eroded anyway. If it would the cause will be a different reason such as arodynamic flows and aiming of the burner or size of the tartget fireball centre. This is a serious problem and should be dealt with by an experienced expert.
For same energy output when energy input is lesser efficiency increase. When maximum heat energy is generated from coal or losses in heat transfer are reduced efficiency increase. Coal in boulder size is burnt combustion may not be complete. There will be more unburnt coal. As per coal chemistry and as per boiler flue gas velocity as designed best coal size for full combustion is designed. Maximum crushed coal is also not the best. Then there will be more coal dust. According to general design in various technologies pulverized coal give best combustion for fbc boilers. For cfbc boilers generally crushed coal size is 6 mm.
When you achieve best combustion mean this is main contributor for increase in efficiency. Boiler design, heat transfer, flue gas velocity, heat losses, are other factors for efficiency.
Advantages: the efficiency of electric dust collector can reach up to about 99%; large gas handling capacity; low flue gas flow rate, low resistance and low operation costs. Shortcomings: complex structure; large size, large area covering; high investments; complex maintenance; special requirements for dust resistance.
Emissions standards for boilers have become very stringent in many areas because of the new Clean Air regulations. The ability of the boiler to meet emissions regulations depends on the type of boiler and burner options. ZOZEN has options to meet 5ppm NOx regulations, as well as 1 ppm CO regulation at 30 ppm NOx out of the box. We can also custom-engineer Selective Catalytic Reduction (SCR) for more rigorous emissions controls.
