喷嘴参数对超临界水热燃烧特性影响的模拟研究

doi:10.11949/0438-1157.20240013

摘要/Abstract

摘要：

反应器喷嘴作用是维持水热火焰在复杂流场中保持稳定。建立内预热式蒸腾壁反应器（IPTWR）内甲醇超临界水热燃烧过程计算流体力学模型，分析了喷嘴的材料热物性和结构参数对进料混合特性及火焰结构的影响规律。结果表明，喷嘴材料传热特性的提高使水热火焰朝着高温和广域的方向发展；氧气-辅热混合段直径由18mm减小到14mm，反应器轴向温度峰值由954.84K增大到981.60K，火焰位置向远端移动；随着喷嘴缩进深度减小，水热火焰逐渐向喷嘴出口聚拢，表现为火焰收缩现象。在此喷嘴结构参数范围内，小直径的短氧气-辅热混合流道，有助于水热火焰的温度升高和聚拢稳定。为内预热式蒸腾壁反应器的喷嘴设计提供理论指导。

关键词: 喷嘴, 反应器, 超临界水, 水热火焰, 计算流体力学

Abstract:

The reactor nozzle acts to maintain the hydrothermal flame stable in a complex flow field. A computational fluid dynamics model of the supercritical hydrothermal combustion process of methanol in an internally preheated transpiration wall reactor (IPTWR) was developed, and the effects of material thermophysical properties and structural parameters of the nozzle on the feed mixing characteristics and flame structure were analyzed. The results show that the improvement of the heat transfer characteristics of the nozzle material makes the hydrothermal flame move toward high temperature and wide area; the diameter of the oxygen-assisted heat mixing section decreases from 18 mm to 14 mm, the peak axial temperature of the reactor increases from 954.84 K to 981.60 K, and the flame position moves toward the distal end; with the decrease of the indentation depth of the nozzle, the hydrothermal flame is gradually converged toward the nozzle outlet, which is manifested as a phenomenon of flame contraction. In this nozzle structure parameter range, the short oxygen-assisted heat mixing flow path with small diameter helps the hydrothermal flame temperature increase and gathering stabilization. Theoretical guidance is provided for the nozzle design of the internal preheated transpiration wall reactor.

Key words: nozzle, reactors, supercritical water, hydrothermal flame, computational fluid dynamics

中图分类号:

TK16

王芝安, 兰忠, 马学虎. 喷嘴参数对超临界水热燃烧特性影响的模拟研究[J]. 化工学报, DOI: 10.11949/0438-1157.20240013.

Zhian WANG, Zhong LAN, Xuehu MA. Simulation study of the effect of nozzle parameters on supercritical hydrothermal combustion characteristics[J]. CIESC Journal, DOI: 10.11949/0438-1157.20240013.

图/表 17

图1 内预热式蒸腾壁反应器的简化二维轴对称物理模型

Fig. 1 2D axisymmetric Simplified physical model of an internally preheated evaporative wall reactor

表1 反应器操作条件

Table 1 Reactor operating conditions

参数	数值
辅助热流体入口流量F_au/(kg·h^-1)	9.53
辅助热流体入口温度T_au/K	825
原料入口流量F_f/(kg·h^-1)	2.97
原料浓度ω_in	0.35
氧化剂入口流量F_ox/(kg·h^-1)	2.45
高温蒸腾水入口流量F_tw1/(kg·h^-1)	19
高温蒸腾水入口温度T_tw1/K	625
低温蒸腾水入口流量F_tw2/(kg·h^-1)	19

图2 网格数量对反应器轴线温度分布的影响

Fig. 2 Effect of the number of grids on the axial temperature distribution of the reactor

图3 不同湍流模型下的模拟温度值与实验测量值的比较

Fig. 3 Comparison of simulated temperature values with experimental measurements for different turbulence models

图4 不同喷嘴材料下的温度场分布云图。(a)钢316L(b)陶瓷(c)绝热材料

Fig. 4 Temperature field distribution with different nozzle materials. (a) Steel 316L (b) Ceramic (c) Adiabatic material

图5 不同喷嘴材料下的氧气流道和甲醇流道内温度变化

Fig. 5 Temperature variation in oxygen and methanol runners with different nozzle materials

图6 不同喷嘴材料下的喷嘴流道内速度变化

Fig. 6 Velocity variation in nozzle runner for different nozzle materials

表2 反应器喷嘴尺寸参数

Table 2 Reactor nozzle size parameters

混合流道直径D_m/mm	喷嘴(内)/mm	喷嘴(中)/mm	喷嘴(外)/mm
14	φ12*3	φ25*5.5	φ42*6
15	φ13*3.5	φ25*5	φ42*6
16	φ14*4	φ25*4.5	φ42*6
17	φ15*4.5	φ25*4	φ42*6
18	φ16*5	φ25*3.5	φ42*6

图7 不同喷嘴直径的反应器中心轴线温度变化曲线

Fig. 7 Temperature variation curves in the center axis of the reactor for different nozzle diameters

图8 不同喷嘴直径下的混合流道内轴向速度云图及流线图

Fig. 8 Axial velocity maps and streamlines in the mixed flow channel for different nozzle diameters

图9 氧气质量分数在混合流道出口上半区的分布曲线(不同混合流道直径)

Fig. 9 Distribution curves of oxygen mass fraction in the upper half of the mixing runner outlet (different mixing runner diameters)

图10 不同喷嘴缩进深度的反应器中心轴线温度分布

Fig. 10 Temperature distribution in the center axis of the reactor for different nozzle indentation depths

图11 喷嘴及火焰区域温度场分布云图

Figure 11 Temperature field distribution in the nozzle and flame region

图12 混合流道内距中心轴线不同位置的轴向速度变化曲线

Fig. 12 Axial velocity variation curves at different positions from the center axis in the mixed flow channel

图13 轴向速度在混合流道出口处的分布曲线(不同喷嘴缩进深度)

Fig. 13 Distribution curve of axial velocity at the outlet of mixing runner (different nozzle indentation depths

图14 不同喷嘴缩进深度下的喷嘴及火焰区域氧气质量分数分布云图

Fig. 14 Oxygen mass fraction distribution in the nozzle and flame region for different nozzle indentation depths

图15 氧气质量分数在混合流道出口处的分布曲线(不同喷嘴缩进深度)

Fig. 15 Distribution curves of oxygen mass fraction at the outlet of the mixing runner (different nozzle indentation depths)

参考文献 32

1	Du X, Zhang R, Gan Z X, et al. Treatment of high strength coking wastewater by supercritical water oxidation[J]. Fuel, 2013, 104: 77-82.
2	Wei N, Xu D H, Hao B T, et al. Chemical reactions of organic compounds in supercritical water gasification and oxidation[J]. Water Research, 2021, 190:116634.
3	Li S B, Xia X B, Qin Q, et al. Decomposition of oil cleaning agents from nuclear power plants by supercritical water oxidation[J]. Nuclear Science and techniques, 2022,33(4): 47.
4	Qin Q, Wang S, Wang H Y, et al. Treatment of radioactive spent extraction solvent by supercritical water oxidation[J]. Journal of Radioanalytical and nuclear Chemistry, 2017, 314(2):1169-1176.
5	Yang J Q, Wang S Z, Li Y H, et al. Novel design concept for a commercial-scale plant for supercritical water oxidation of industrial and sewage sludge[J]. Journal of Environmental Management, 2019, 233:131-140.
6	Chen Z, Chen H Z, Liu X L, et al. An inclined plug-flow reactor design for supercritical water oxidation[J]. Chemical Engineering Journal, 2018, 343:351-361.
7	石德智, 张金露, 胡春艳, 等. 超临界水氧化技术处理污泥的研究与应用进展[J]. 化工学报, 2017, 68(1):37-49.
	Shi D Z, Zhang J L, Hu C Y, et al. Research and application progress of supercritical water oxidation technology on waste sludge treatment[J]. CIESC Journal, 2017, 68(1):37-49.
8	闫正文, 廖传华, 廖玮, 等. 无机盐在超临界水中的溶解度研究[J]. 应用化工, 2018, 47(3):514-516.
	Yan Z W, Liao C H, Liao W, et al. A study on the solubility of inorganic salts in supercritical water[J]. Applied Chemical Industry, 2018, 47(3):514-516.
9	Qin Q, Wang S, Peng H H, et al. Solubility of radioactive inorganic salt in supercritical water[J]. Journal of Radioanalytical and Nuclear Chemistry, 2018, 317(2):947-957.
10	Xu D H, Huang C B, Wang S Z, et al. Characteristics analysis of water film in transpiring wall reactor[J]. International Journal of Heat and Mass Transfer, 2016, 100:559-565.
11	Xu D H, Feng P, Wang Y, et al. Effects of structural parameters on water film properties of transpiring wall reactor[J]. AIChE Journal, 2022, 68(2): 17472-1-17472-11.
12	Bermejo M D, Fdez-Polanco F, Cocero M J. Experimental study of the operational parameters of a transpiring wall reactor for supercritical water oxidation[J]. The Journal of Supercritical Fluids, 2006, 39(1):70-79.
13	Xu D H, Wang S Z, Huang C B, et al. Transpiring wall reactor in supercritical water oxidation[J]. Chemical Engineering Research and Design, 2014, 92(11):2626-2639.
14	Xu D H, Huang C B, Wang S Z, et al. Salt deposition problems in supercritical water oxidation[J]. Chemical Engineering Journal, 2015, 279:1010-1022.
15	Reddy S N, Nanda S, Okolie J A, et al. Hydrothermal flames for subaquatic, terrestrial and extraterrestrial applications[J]. Journal of Hazardous Materials, 2022, 424:127520.
16	Fan M J, Shao S Y, Wang H Z, et al. Numerical analysis of hydrogen-oxygen hydrothermal combustion: Laminar counterflow diffusion flames[J]. International Journal of Hydrogen Energy, 2024, 49:278-292.
17	He W Q, Li Z C, Li Y H, et al. Prospects of supercritical hydrothermal combustion as recovery technology for heavy oil reservoirs[J]. Geoenergy Science and Engineering, 2023, 227:211795.
18	Liang Z J, Zhang F M, Li M Y, et al. Formation and evolution characteristics of hydrothermal flames inside a transpiring wall reactor: a transient numerical investigation[J]. The Journal of Supercritical Fluids, 2022, 188:105692.
19	Reddy S N, Nanda S, Kumar P, et al. Impacts of oxidant characteristics on the ignition of n-propanol-air hydrothermal flames in supercritical water[J]. Combustion and Flame, 2019, 203:46-55.
20	Zhang F M, Xu C Y, Zhang Y, et al. Experimental study on the operating characteristics of an inner preheating transpiring wall reactor for supercritical water oxidation: Temperature profiles and product properties[J]. Energy, 2014, 66:577-587.
21	唐旭, 陈海峰, 阳明君, 等. 超临界水氧化/气化反应器的CFD模拟研究进展[J]. 应用化工, 2021, 50(2):504-510, 515.
	Tang X, Chen H F, Yang M J, et al. Current research processes in CFD simulation of supercritical water oxidation/gasification reactor[J]. Applied Chemical Industry, 2021, 50(2):504-510, 515.
22	Feng P, Xu D H, Ma M Y, et al. Effects of key parameters on water film properties and temperature field distribution inside transpiring wall reactor[J]. The Journal of Supercritical Fluids, 2023, 192:105811.
23	Fan M J, Li G X, Wang H X, et al. Numerical study of hydrogen hydrothermal combustion characteristics in a coaxial nozzle burner[J]. The Journal of Supercritical Fluids, 2022, 183:105537.
24	Sierra-Pallares J, Parra-Santos M T, García-Serna J, et al. Numerical analysis of high-pressure fluid jets: Application to RTD prediction in supercritical reactors[J]. The Journal of Supercritical Fluids, 2009, 49(2):249-255.
25	Ren M M, Wang S Z, Roekaerts D. Numerical study of the counterflow diffusion flames of methanol hydrothermal combustion: The real-fluid effects and flamelet analysis[J]. The Journal of Supercritical Fluids, 2019, 152:104552.
26	Brock E E, Oshima Y Savage P E, et al. Kinetics and mechanism of methanol oxidation in supercritical water[J]. The Journal of Physical Chemistry, 1996, 100(39):15834-15842.
27	Zhang F M, Ma J N, Su C J. Study on the uniformity of water film in a transpiring wall reactor for supercritical water oxidation[J]. The Canadian Journal of Chemical Engineering, 2020, 98(7):1631-1644.
28	Bermejo M D, Martín Á, Queiroz J P S, et al. Computational fluid dynamics simulation of a transpiring wall reactor for supercritical water oxidation[J]. Chemical Engineering Journal, 2010, 158(3):431-440.
29	Zhang J, Ren M M, Li Y H, et al. Continuous supercritical hydrothermal combustion experimental and burner structure optimization simulation study[J]. Chemical Engineering Research and Design, 2022, 188:69-80.
30	Zhang F M, Chen J L, Su C J, et al. Combined effects of protective film and oxidant on the performance of the supercritical water oxidation system with a film protective reactor: a simulation study[J]. Process Safety and Environmental Protection, 2019, 131:268-281.
31	Wang C J, Wang Y, Fan X Z, et al. Preparation and thermophysical properties of La₂(Zr_0.7Ce_0.3)₂O₇ ceramic via Sol–gel process[J]. Surface and Coatings Technology, 2012, 212:88-93.
32	Zhang F M, Yang J, Ma J N, et al. Optimization of structural parameters of an inner preheating transpiring-wall SCWO reactor[J]. Chemical Engineering Research and Design, 2019, 141:372-387.

[1]	詹小斌, 王会彬, 蒋亚龙, 史铁林. 声共振混合器高黏度流体混合的功耗特性研究[J]. 化工学报, 2024, 75(2): 531-542.
[2]	李文俊, 赵中阳, 倪震, 周灿, 郑成航, 高翔. 基于气-液传质强化的湿法烟气脱硫CFD模拟研究[J]. 化工学报, 2024, 75(2): 505-519.
[3]	麻雪怡, 刘克勤, 胡激江, 姚臻. POE溶液聚合反应器内混合与反应过程的CFD研究[J]. 化工学报, 2024, 75(1): 322-337.
[4]	王婷, 王忠东, 项星宇, 何呈祥, 朱春英, 马友光, 付涛涛. 微反应器内环酯类锂电池添加剂合成研究进展[J]. 化工学报, 2024, 75(1): 95-109.
[5]	张思雨, 殷勇高, 贾鹏琦, 叶威. 双U型地埋管群跨季节蓄热特性研究[J]. 化工学报, 2023, 74(S1): 295-301.
[6]	肖明堃, 杨光, 黄永华, 吴静怡. 浸没孔液氧气泡动力学数值研究[J]. 化工学报, 2023, 74(S1): 87-95.
[7]	温凯杰, 郭力, 夏诏杰, 陈建华. 一种耦合CFD与深度学习的气固快速模拟方法[J]. 化工学报, 2023, 74(9): 3775-3785.
[8]	陈哲文, 魏俊杰, 张玉明. 超临界水煤气化耦合SOFC发电系统集成及其能量转化机制[J]. 化工学报, 2023, 74(9): 3888-3902.
[9]	韩晨, 司徒友珉, 朱斌, 许建良, 郭晓镭, 刘海峰. 协同处理废液的多喷嘴粉煤气化炉内反应流动研究[J]. 化工学报, 2023, 74(8): 3266-3278.
[10]	郑玉圆, 葛志伟, 韩翔宇, 王亮, 陈海生. 中高温钙基材料热化学储热的研究进展与展望[J]. 化工学报, 2023, 74(8): 3171-3192.
[11]	岳林静, 廖艺涵, 薛源, 李雪洁, 李玉星, 刘翠伟. 凹坑缺陷对厚孔板喉部空化流动特性影响研究[J]. 化工学报, 2023, 74(8): 3292-3308.
[12]	邢雷, 苗春雨, 蒋明虎, 赵立新, 李新亚. 井下微型气液旋流分离器优化设计与性能分析[J]. 化工学报, 2023, 74(8): 3394-3406.
[13]	汪林正, 陆俞冰, 张睿智, 罗永浩. 基于分子动力学模拟的VOCs热氧化特性分析[J]. 化工学报, 2023, 74(8): 3242-3255.
[14]	何晓崐, 刘锐, 薛园, 左然. MOCVD生长AlN单晶薄膜的气相和表面化学反应综述[J]. 化工学报, 2023, 74(7): 2800-2813.
[15]	董明, 徐进良, 刘广林. 超临界水非均质特性分子动力学研究[J]. 化工学报, 2023, 74(7): 2836-2847.