How to Choose Burners for Gas Boiler Renovation?
In recent years, with the concern for environmental pollution, coal-fired steam boilers have gradually been replaced by natural material and natural gas boilers. With the expansion of the sales market for natural materials and natural gas boilers, everyone's focus has shifted to natural materials and natural gas boilers. How to choose a natural gas boiler burner as the core component?The emission indicators of boilers, especially the NOx emission concentration, are closely related to the coal type, boiler selection, and burner type. For operating boilers, the furnace type has been determined. However, in recent years, coal-fired power plants have mixed and inferior coal quality in order to increase profitability and cope with the ever-changing market of electric coal. Therefore, before the transformation of low nitrogen combustion technology, the existing main and commonly used coal types of boilers should be fully evaluated. In the feasibility study of the transformation, there are many cases where the improper selection of coal types has caused the unclear NOx emission reduction effect and new problems after the transformation. Secondly, a thorough test of the operating boilers is conducted to fully evaluate the combustion performance, steam parameters, and affected coal types that exist in the operation of the boilers. To address issues such as hot surface wall temperature, coking and slagging, operation adjustment, and thermal automation, propose scientific and reasonable transformation goals, balance boiler economic and environmental indicators, and effectively improve existing problems through transformation. Because of the diversity and originality of gasoline and diesel gas heating furnaces. Many people are not aware of the difficult matching problem between gasoline and diesel gas heating furnaces and burners. The selection becomes smaller, and the gasoline and diesel gas heating furnace cannot fully utilize all normal professional abilities; Choosing a larger size will lead to the consumption of gasoline, diesel, and fuel. So how to choose a suitable natural gas boiler burner based on the output power of the heating furnace and its specific requirements?1、 The selection of burners by manufacturers mainly includes imported or domestic burners. The main characteristics of imported burners are complete technology, high level of refined management, high efficiency in environmental protection, and high cost-effectiveness (high safety factor, stable system software), but at the same time, the price is also high. The software of China's natural gas burner system is immature, with poor reliability and low thermal efficiency, but it is cheap. Nowadays, the key well-known brands of imported burners include: Italy's Europa Burner, Spain's Riyalo, Spain's Baide, General, Italian flange, Italian Gao, UK's Maxon, France's Wessot, USA's Liwei, Germany's Olin, and so on. Key well-known brands of domestic burners include Zhejiang Baite, Ouruite, Baitesi, etc. Our company generally strongly recommends the use of imported burners, taking into account factors such as reliability, safety factor, and high efficiency.2、 The selection of burner for natural materials depends on the different key components of the ignited natural materials.3、 The method of model selection is mainly based on the thermal power of the boiler to select the thermal power of the combustion engine (the model is determined by the thermal power of the combustion engine)The method of model selection is mainly based on the thermal power of the heating furnace to select the thermal power of the burner (determined by the thermal power of the burner to determine the model specifications). 1. The calculation method of the burner output power: burner output power=heating furnace output power/thermal efficiency. Clarify the model specifications of the burner, and select the appropriate working pressure and total flow rate of the burner according to the specific requirements. Natural gas burner: The total natural gas flow rate [m3n/h] is specified as (burner output power [KW]) × 3.6)/[Steam heating capacity MJ/m3n]; Gas diesel burner: The required total flow rate of gasoline and diesel [Kg/h]=(burner output power [KW]) × 3.6)/Heat generation of gasoline and diesel [MJ/Kg]. 2. Selecting valve groups for natural gas and dual fuel burners (key for natural gas boilers): Use a valve group selection table to select valve groups with sufficient specifications. It is important to note that the value in the valve group selection table is based on the data information when the back pressure of the heating furnace is 0. When selecting valve groups, it is important to reduce the specific natural gas working pressure by the back pressure of the heating furnace. The steam in the valve group selection table is gas. 3. Verify the connection specifications of the burner, especially that the ignition head must be suitable for the heating furnace. The length of the ignition head in the heating furnace should be 10-20mm, with the ignition head protruding from the fire throat. Check the specifications of the flames in the flame size chart, and try to be careful not to let the flames touch the stove.After the transformation of the low nitrogen burner, although NOx has decreased significantly, even when using the same coal type, the combustible content of fly ash has increased significantly. The main low nitrogen combustion technology adopts low-temperature and low oxygen combustion, which leads to a significant decrease in temperature in the main combustion zone. It controls and delays the ignition of coal powder, reduces the oxygen content in the ignition zone, reduces the ability of coal powder to burn out, prolongs the combustion process, and increases the combustible content of fly ash and slag. During some renovations, the area of the burner's primary and secondary air nozzles and the exhaust air nozzle was changed, resulting in a delay in the mixing of secondary and primary air, which is not conducive to the ignition and combustion of coal powder airflow. According to the test data of the renovated boiler, the combustible increase in fly ash of the four corner tangential combustion boiler is 0.5-1 percentage points, the combustible increase in fly ash of the counter combustion boiler is 1-1.5 percentage points, and the combustible increase in fly ash of the "W" flame combustion boiler is 2-4 percentage points, which affects the boiler efficiency by 0.4-1.6 percentage points.In summary, customers should select and integrate scientific research on gasoline and diesel gas heating furnaces based on their specific situation, ensuring high efficiency, environmental protection, energy conservation, stability, and suitability for their own gasoline and diesel gas heating furnaces.