煤种对气化炉的影响

1 CONFIDENTIAL SCGP Users Conference 11 December 2007 Beijing 壳牌煤气化用户会议 2007年12月北京 Coal properties and gasifier operating window 煤的特性及气化炉操作窗口 2 CONFIDENTIAL Problems experienced due to slag: 由于渣造成的问题 slag entrainment from gasifier outlet cone to quench and syngas cooler 熔渣被从气化炉出口带出到急冷段和合成气冷却 器 insufficient wetting of the membrane wall with slag 水冷壁不充分挂渣 slag running into the burner muffles 渣流入烧嘴罩里面 slag lump formation and slag tap plugging 大渣块生成及渣口堵塞 3 CONFIDENTIAL Erosion of HPHT candles due to slag entrainment (also erodes syngas cooler internals) 由于飞渣造成的高稳高压飞灰过滤器滤芯磨蚀(也包括合成气冷却器的磨蚀) 4 CONFIDENTIAL Slag running into burner muffle, distortion of flame and syngas flow, leading to burner muffle leaks 由于渣进入烧嘴罩,干扰火焰和合成气流动,导致烧嘴罩泄露 5 CONFIDENTIAL Insufficient slag coverage of membrane wall, hot syngas attacks studs, refractory, damaging membrane wall tube material. 水冷壁不充分挂渣,热合成气损坏了钉头,耐火衬里和水冷壁管 6 CONFIDENTIAL Plugged slag tap resulting in slag level in gasifier 气化炉渣口堵塞 7 CONFIDENTIAL and with 40% of limestone on ash 添加40%的基于灰分的石灰石 Fluxing with 10% of limestone on ash 添加10%的基于灰分的石灰石 3 8 CONFIDENTIAL Sketch of membrane wall and temperature profile 水冷壁及温度场的示意图 9 CONFIDENTIAL Operating window gasifier:气化炉的操作窗口 • Flowing slag temperature must be higher than fluid temperature (FT or T4) or temperature for critical viscosity (Tcv) 渣的流动温度必须比渣的流动温度(FT或T4) 或者临界温度高 • 2 Pa.s < slag viscosity < 25 Pa.s 2 Pa.s<渣的粘度<25Pa.s • 8% wt < ash content in coal to burners < 35% wt. 8% 重量<进入烧嘴的煤的灰份含量< 35% 重量 T,gasifier =T,slag+ (150~200) deg C 气化温度=渣的流动温度+(150~200)度 10 CONFIDENTIAL HM196 phase diagram HM196 煤的灰分相图 Original ash without flux (corrected shell) Ash with flux (corrected shell) 20 %wt FeO Weight % SiO2 Weight Weight Al2O3 SiO2 CaO 11 CONFIDENTIAL Slag viscosity & temperature HM196 with 6.4% CaO on Ash 渣的粘温曲线 HM196 灰基基础6.4%氧化钙添加 T,gasifier =1525 °C 气化温度=1525度 T,slag = 1350 °C 渣的流动温度=1350度 Temperature window. 气化温度操作窗口气化温度操作窗口气化温度操作窗口气化温度操作窗口 Slag: [1300–1400] °C 渣:[1300–1400] 度 Gasifier:[1475–1575] °C 气化炉:[1475–1575] 度 12 CONFIDENTIAL Original ash without flux (corrected shell) Ash with flux (corrected shell) 10 %wt FeO Weight Weight Weight % SiO2 Shifan mine #2 phase diagram 示范矿#2煤的灰分相图 13 CONFIDENTIAL Slag viscosity & temperature Shifan #2 with 5.22% CaO on ash 渣的粘温曲线示范2号煤灰基基础5.22%氧化钙添加 T,gasifier =1650 °C 气化温度=1650度 T,slag = 1490 °C 渣的流动温度=1490度 Temperature window 气化温度操作窗口气化温度操作窗口气化温度操作窗口气化温度操作窗口 Slag:[1350–1630] °C 渣:[1350–1630] 度 Gasifier:[1510–1790] °C 气化炉:[1510–1790] 度 14 CONFIDENTIAL 1350 - 16301300 - 1400Slag Temp operating window, °C 操作窗口 Long slag 长操作窗口 Short slag 短操作窗口 13501300T, fluid °C 5.26.4CaO added, %wt on Ash 2.801.86SiO2 / Al2O3, W/W 10.4622.63Fe2O3, %wt 20.3621.91Al2O3, %wt 56.9640.72SiO2, %wt Shifan #2 mineHM196coal 15 CONFIDENTIAL 长治北煤的相图 phase diagram Original ash without flux (corrected shell) Ash with flux (corrected shell) 5 %wt FeO Weight Weight Weight % SiO2 Dry flux Fresh ash Total ash content 20.00 0.00 2.99 Corretced iron content With flux Without flux 3.60 24.00 Total dry flux Base on ash Base on AR coal 35.70 8.57 SiO2/Al2O3 With flux Without flux 1.17 1.17 (8%) 16 CONFIDENTIAL 长治北煤的粘温曲线(8% 石灰石) T,gasifier =1600 °C T,slag = 1450 °C Temperature window. Slag:[1400-1500] °C Gasifier:[1550–1650] °C 17 CONFIDENTIAL Original ash without flux (corrected shell) Ash with flux (corrected shell) 5 %wt FeO Weight Weight Weight % SiO2 Dry flux Fresh ash Total ash content 20.00 0.00 3.71 Corretced iron content With flux Without flux 4.46 24.00 Total dry flux Base on ash Base on AR coal 35.70 8.57 SiO2/Al2O3 With flux Without flux 2.00 2.00 米村煤的相图 phase diagram(8%) 18 CONFIDENTIAL 米村煤的粘温曲线(8% 石灰石) T,gasifier =1610 °C T,slag = 1460 °C Temperature window. Slag:[1380-1540] °C Gasifier:[1530–1690] °C 19 CONFIDENTIAL 1380 - 15401400 - 1500Slag Temp operating window, °C Long slagShort slag 13801400T, fluid °C 88Flux added, %wt on AR coal 2.031.17SiO2 / Al2O3, W/W 4.913.91Fe2O3, %wt 27.5538.06Al2O3, %wt 55.2344.69SiO2, %wt 米村煤长治北coal 20 CONFIDENTIAL Coal selection guideline to avoid gasifier problems (burner muffle, membrane wall, slag tap) : 煤种选择指导原则来避免气化炉问题(烧嘴罩,水冷壁, 渣口) 1) Consistency in coal supply and frequent coal analyses 稳定的煤供应和日常生产的煤性质检查 2) 8.5 %wt < ash content in AR coal < 35 %wt 8.5 %wt<收到基的灰份含量 < 35 %wt 3) Ash content variation as low as possible (+/- 10% relative) 煤的灰份变化尽可能的小 (在+/- 10% 范围内) 4) SiO2/Al2O3 > 1.8 (long slag) and proper fluxing to stay within slag viscosity range of 2 – 25 Pa.s 希望是操作窗口大的煤,及SiO2/Al2O3 > 1.8,添加合适的石灰石使渣的 粘度范围保持在2 – 25 Pa.s 21 CONFIDENTIAL Variation in heating value of HM181 coal due to ash content 24 26 28 30 32 34 36 19.00 20.00 21.00 22.00 23.00 24.00 25.00 26.00 27.00 ash (Aad), %wt H H V , M J / k g Moisture and Ash Free As Received HM181灰份变化与热值的影响 22 CONFIDENTIAL Effect on Gasifier Temperature because of ash variation of HM181 coal with different control modes 1525 1545 1565 1585 1605 1625 1645 1665 1685 19 20 21 22 23 24 25 26 27 ash content, %wt (Aad) T , g a s i f i e r , ° C CO2 control O2/C, control gas steam make control Base case @ 1600 °C HM181很大不同控制模式对气化温度的影响 气化炉蒸汽控制 二氧化碳控制 氧煤比控制基准状态 1600C 23 CONFIDENTIAL Comparison different gasifier control modes 不同的气化炉控制比较 +++ Fast, gradual 迅速,平稳 +++ Slow, jump 缓慢,有扰动 SP change in case of coal change 煤种变化后设定点的调整 1- 2 minutes 1到2分钟 5 to 10 minutes 5到10分钟 Hours 几个小时 Response time in case of coal change 当煤种变化后的反应时间 25 °C 25度 30 °C 30度 125 °C 125度 ∆T, gasifier with ash variation 随灰份变化造成的气化温 度变化 Gasifier steam make 气化炉蒸汽控制 CO2 二氧化碳控制 O2/C ratio 氧煤比控制 Control mode 控制模式 24 CONFIDENTIAL Gasifier operations气化炉操作建议 Target: Keeping gasifier temperature ∆T within +/- 50 ° C 目标: 确保气化操作温度变化在+/- 50 度 ● Analysis of coal feed on ash content and ash composition to determine fluxing and gasifier temperature 对煤进料的灰含量和灰组成进行分析来确定石灰石的添加量和气化温度 ● Coal mass flow within +/-5% and do not trip burners 煤分的质量流量稳定在 +/-5%内防止造成烧嘴跳车 ● Use CO2 or gasifier steam make control 使用CO2和气化炉蒸汽控制 ● Gasifier steam make faster than CO2 control and less sensitive to Heating Value variations 气化炉蒸汽控制比二氧化碳控制更快,更有效的应对煤热值的变化