How to select burner for gas boiler transformation?

How to select burner for gas boiler transformation?
In recent years, with the concern of environmental pollution, coal-fired steam boilers have been gradually replaced by natural gas and natural gas boilers. With the expansion of the sales market of natural materials and natural gas boilers, everyone's focus has also shifted to natural materials and natural gas boilers. How to choose the natural gas boiler burner as the core component?
The emission index of boiler, especially the emission concentration of NOx, is closely related to the coal type, boiler type selection and burner type. For the boiler in operation, the boiler type has been determined. However, in recent years, in order to increase the profitability of coal-fired power plants and cope with the changing market of electric coal, the coal quality used by the boiler is mostly mixed and inferior to the original design coal type. Therefore, before the transformation of low nitrogen combustion technology, First of all, it is necessary to fully evaluate the existing main coal types and common coal types of the boiler. In the feasibility study of the transformation, due to the improper selection of coal types, the NOx emission reduction effect after the transformation is not obvious and there are many new problems. Secondly, it is necessary to carry out a thorough test on the boiler in operation, and fully evaluate the problems of combustion performance, steam parameters, heating surface wall temperature, coking and slagging, operation adjustment, thermal automation and other aspects in the operation of the boiler, Put forward the expected goal of scientific and reasonable transformation, weigh the boiler economic indicators and environmental indicators, and effectively improve the existing problems through transformation. Because of the diversity and originality of the gasoline and diesel heating furnace. Many people do not understand the problem of matching the gas and diesel heating furnace with the burner. The selection becomes smaller, and the gasoline and diesel gas heating furnace cannot fully exert all normal professional abilities; Larger selection will lead to consumption of gasoline and diesel fuel. So how to select suitable natural gas boiler burners according to the output power of the heating furnace and its specific needs?
1、 The burners selected by manufacturers are mainly imported or domestic burners. The main characteristics of the imported burner are perfect technology, high level of refined management, high efficiency and environmental protection, and high cost performance (high safety factor, stable system software), but at the same time, the price is also high. China's natural gas burner system software is immature, has poor reliability and low thermal efficiency, but its price is cheap. Today, the key brands of imported burners include: Italian Europa burner, Spanish Riyalo, Spanish Bud, General, Italian flange, Italian high, British Maxon, French Vesso, American Liwei, German Olin, etc. Key well-known brands of domestic burners include:, Zhejiang Baite, Ouruite, Baites, etc. Our company generally strongly recommends the use of imported burners, and key factors such as reliability, safety factor and high efficiency are considered.
2、 The burners for fuel selection are divided according to the different key points of the ignited fuel.
3、 The mode of model selection is mainly to select the thermal power of the combustion engine according to the thermal power rate of the boiler (the model is determined by the thermal power of the combustion engine)
The model selection method is mainly to select the thermal power of the burner according to the thermal power rate of the heating furnace (the model and specification are determined by the thermal power of the burner). 1. The calculation method of the burner output power: the burner output power=the heating furnace output power/thermal efficiency. The model and specification of the burner are defined, and the working pressure and total flow of the appropriate burner must be selected according to the specific conditions. Natural gas burner: specified total flow of natural gas [m3n/h]=(burner output power [KW] × 3.6)/[steam body heating capacity MJ/m3n]; Gas and diesel burner: demand for total flow of gas and diesel [Kg/h]=(burner output power [KW] × 3.6)/calorific value of gasoline and diesel [MJ/Kg]. 2. Select valve groups for natural gas and dual-fuel burners (key for natural gas boilers): use the valve group selection table to select and install valve groups with sufficient specifications. It must be noted that the standard value of the valve group selection table is the data information when the back pressure of the heating furnace is 0. When selecting valve groups, be sure to reduce the specific working pressure of natural gas from the back pressure of heating furnace to select valve groups. The steam in the valve group selection table is gas. 3. Check the connection specification of the burner, especially the igniter must be suitable for the heating furnace. The length of the igniter in the heating furnace should be 10-20mm with the igniter protruding the fire throat. Check the flame specification in the flame size drawing. Please try to keep the flame away from the furnace mouth.
After the transformation of the low nitrogen burner, although the reduction of NOx is very large, even when burning the same coal, the increase of fly ash combustibles is also large. The main reason is that the low nitrogen combustion technology adopts low temperature and low oxygen combustion. The temperature in the main combustion zone decreases a lot. The ignition of pulverized coal is controlled and delayed, and the oxygen content in the ignition zone is reduced, so that the ability of pulverized coal to burn out is reduced, the combustion process is prolonged, and the combustible content of fly ash and slag is increased. In some retrofits, the area of the burner's primary and secondary air nozzles and the burned-out air nozzles has been changed, resulting in the delay of the mixing of secondary air and primary air, which is not conducive to the ignition and combustion of pulverized coal airflow. According to the test data of the retrofitted boiler, for the tangentially fired boiler, the increase of fly ash combustibles is 0.5-1 percentage points, for the contra-combustion boiler, the increase of fly ash combustibles is 1-1.5 percentage points, and for the "W" flame fired boiler, the increase of fly ash combustibles is 2-4 percentage points, affecting the boiler efficiency by 0.4-1.6 percentage points.
In short, customers should integrate the scientific research and selection of gasoline and diesel gas heating furnace according to their own specific conditions to ensure the high efficiency, environmental protection, energy conservation, stability and suitable for their own gasoline and diesel gas heating furnace.