Whether a fully automatic oil (gas) burner with outstanding performance is installed on a boiler, whether it still has the same outstanding combustion performance, depends largely on whether the gas dynamic characteristics of the two match. Only a good match can play the function of the burner, ensure the stable combustion of the furnace, achieve the expected heat output, and obtain the outstanding thermal efficiency of the boiler.
1. Matching of gas dynamic characteristics
A single fully automatic burner is like a flamethrower, which sprays flames into the furnace (combustion chamber) to achieve complete combustion and output heat in the furnace; the burner manufacturer measures the completeness of combustion of the product in Specific specifications are carried out within the combustion chamber. Therefore, the conditions of standard experiments are generally used as the selection conditions of burners and boilers. These conditions can be summed up as follows:
(1) power;
(2) Airflow pressure in the furnace;
(3) The space size and geometric shape (diameter and length) of the furnace.
The so-called matching of aerodynamic characteristics refers to the degree to which these three conditions are met.
2. Power
The power of the burner refers to how much mass (kg) or volume (m3/h, under standard conditions) of fuel it can burn per hour when it is fully burned, and also gives the corresponding heat output (kw/h or kcal/h ). The boiler is calibrated with the steam output value and the fuel consumption at the same time, and the two must match when selecting.
3. Gas pressure in the furnace
In an oil (gas) boiler, the hot air flow starts from the burner and is exhausted to the atmosphere through the furnace, heat exchanger, flue gas collector and exhaust pipe, forming a fluid thermodynamic process. The pressure head of the upstream of the hot air flow generated after combustion flows in the furnace channel, just like the water in the river, and the potential difference (drop, water head) flows downstream. Because the furnace wall, channel, elbow, baffle, gorge and chimney all have resistance to the flow of gas (called flow resistance), which will cause pressure loss. If the pressure head cannot overcome the pressure loss along the process, the movement will be can not achieve. Therefore, it is necessary to maintain a certain flue gas pressure in the furnace, which is called back pressure for the burner. For boilers without air induction devices, the furnace pressure must be higher than the atmospheric pressure after considering the pressure head loss along the way.
The size of the back pressure directly affects the output of the burner, and the back pressure is related to the size of the furnace, the length and geometry of the flue. A boiler with a large flow resistance requires a high pressure of the burner. For a specific burner, the pressure head has a larger value, which corresponds to a larger damper and a larger air flow state. When the intake throttle changes, the air volume and pressure also change, and the output of the burner also changes. The pressure head is small when the air volume is small, and the pressure head is high when the air volume is large. For a specific boiler, when the incoming air volume is large, the flow resistance will increase accordingly, which will increase the back pressure of the furnace, and the increase of the back pressure of the furnace will restrain the air output of the burner. Therefore, it must be understood when choosing a burner Its power curve is reasonably matched.
Whether a fully automatic oil (gas) burner with outstanding performance is installed on a boiler, whether it still has the same outstanding combustion performance, depends largely on whether the gas dynamic characteristics of the two match. Only a good match can play the function of the burner, ensure the stable combustion of the furnace, achieve the expected heat output, and obtain the outstanding thermal efficiency of the boiler.
1. Matching of gas dynamic characteristics
A single fully automatic burner is like a flamethrower, which sprays flames into the furnace (combustion chamber) to achieve complete combustion and output heat in the furnace; the burner manufacturer measures the completeness of combustion of the product in Specific specifications are carried out within the combustion chamber. Therefore, the conditions of standard experiments are generally used as the selection conditions of burners and boilers. These conditions can be summed up as follows:
(1) power;
(2) Airflow pressure in the furnace;
(3) The space size and geometric shape (diameter and length) of the furnace.
The so-called matching of aerodynamic characteristics refers to the degree to which these three conditions are met.
2. Power
The power of the burner refers to how much mass (kg) or volume (m3/h, under standard conditions) of fuel it can burn per hour when it is fully burned, and also gives the corresponding heat output (kw/h or kcal/h ). The boiler is calibrated with the steam output value and the fuel consumption at the same time, and the two must match when selecting.
3. Gas pressure in the furnace
In an oil (gas) boiler, the hot air flow starts from the burner and is exhausted to the atmosphere through the furnace, heat exchanger, flue gas collector and exhaust pipe, forming a fluid thermodynamic process. The pressure head of the upstream of the hot air flow generated after combustion flows in the furnace channel, just like the water in the river, and the potential difference (drop, water head) flows downstream. Because the furnace wall, channel, elbow, baffle, gorge and chimney all have resistance to the flow of gas (called flow resistance), which will cause pressure loss. If the pressure head cannot overcome the pressure loss along the process, the movement will be can not achieve. Therefore, it is necessary to maintain a certain flue gas pressure in the furnace, which is called back pressure for the burner. For boilers without air induction devices, the furnace pressure must be higher than the atmospheric pressure after considering the pressure head loss along the way.
The size of the back pressure directly affects the output of the burner, and the back pressure is related to the size of the furnace, the length and geometry of the flue. A boiler with a large flow resistance requires a high pressure of the burner. For a specific burner, the pressure head has a larger value, which corresponds to a larger damper and a larger air flow state. When the intake throttle changes, the air volume and pressure also change, and the output of the burner also changes. The pressure head is small when the air volume is small, and the pressure head is high when the air volume is large. For a specific boiler, when the incoming air volume is large, the flow resistance will increase accordingly, which will increase the back pressure of the furnace, and the increase of the back pressure of the furnace will restrain the air output of the burner. Therefore, it must be understood when choosing a burner Its power curve is reasonably matched.