提高锅炉等离子体火炬燃弧稳定性的参数调整方法研究

Parameter Adjustment Method of Plasma Torch Used in Boiler for Improving Arc Burning Stability

等离子体点火(也称等离子体火炬)已广泛应用于火力发电厂的锅炉点火,但由于系统复杂,工作环境恶劣,运行一段时间后容易出现起弧困难、频繁熄弧等问题。以某次点火过程中出现频繁熄弧问题为切入点,对等离子体火炬熄弧现象的数据进行了统计分析,研究提高燃弧稳定性的方法。结合简易电弧理论模型和试验数据,明确了电弧电压与轴向气压的强相关性,提出了定量评价燃弧质量的统计指标,并结合历史数据和正常设备数据对熄弧现象进行对比分析。研究发现,此次点火过程中火炬状态发生变化,在轴向气压未调整的情况下,出现电弧电压超过额定值的现象,导致了电源电压裕量不足,进而降低了燃弧稳定性。利用电弧电压与轴向气压的强相关性,通过拟合其线性关系可对电弧电压定量调整,调整后实现稳定燃弧。火炬的状态存在动态变化的现象,运行参数宜根据当前电弧特性动态调整,避免电压过高引发熄弧。研究结果可以为相关设备故障分析、提高点火装置运行管理水平和相关技术改造提供理论和方法参考。

Plasma torches are currently widely used in boiler ignition in thermal power plants.However,the plasma torch system is complex,and the working environment is harsh.After running for a period of time,problems such as difficulty in arc ignition and arc extinguishing often occur.Focus on the frequent arc extinguishing during a certain ignition process,the adjustment method of improving the stability of arc burning is studied.Combined with the simplified arc model and experimental data,the strong correlation between the arc voltage and axial air pressure is clarified.A quantitative evaluation indicators based on statistical method for arc burning quality is proposed,and the arc extinguishing phenomenon in conjunction with historical data and normal equipment is compared.It is found that due to the state of the torch changed and the axial pressure keeping unchanged,the torch arc voltage exceeded the rated value in this ignition,causing insufficient power supply,thereby reducing the arc stability.A linear relationship between the arc voltage and the axial air pressure is used to adjust the arc voltage.The stability of arc burning is improved after adjustment.the operating parameters should be dynamically adjusted according to the current arc characteristics to avoid arc extinguishing caused by excessive voltage.The results can provide theoretical and method references for relevant equipment problems analyzing,improving the management of ignition devices and related technical transformations.