比表面积与入口气体分压对热解炭微观结构影响的数值模拟研究

doi:10.15541/jim20150528

无机材料学报 ›› 2016, Vol. 31 ›› Issue (12): 1327-1334.DOI: 10.15541/jim20150528 CSTR: 32189.14.10.15541/jim20150528

比表面积与入口气体分压对热解炭微观结构影响的数值模拟研究

许健¹, 汤哲鹏², 彭雨晴², 顾传青¹, Koyo Norinaga³, 李爱军²

(1. 上海大学理学院, 数学系, 上海 200444; 2. 上海大学材料复合及先进分散技术教育部工程中心, 上海 200444; 3. 九州大学材料化学与工程学院, 日本福冈 816-8580)

收稿日期:2015-10-26 修回日期:2016-03-22 出版日期:2016-12-16 网络出版日期:2016-11-23
作者简介:许健(1991–), 男, 硕士研究生. E-mail: sky3273626@163.com
基金资助:
基金项目:国家自然科学基金(11371243);上海市教委重点创新项目(13ZZ068);上海市科委重点项目(S30104);教育部博士点基金(20113108120019);航空基金(2013ZFS6001);上海市科委项目(13521101202)

Numerical Simulation for Influence of Surface Area/Volume Ratio and Inlet Gas Pressure on Pyrolytic Carbon Texture

XU Jian¹, TANG Zhe-Peng², PENG Yu-Qing², GU Chuan-Qing¹, KOYO Norinaga³, LI Ai-Jun²

(1. Department of Mathematics, College of Sciences, Shanghai University, Shanghai, 200444, China; 2. Research Center for Composite Materials, Shanghai University, Shanghai, 200444, China; 3. Kyushu University, Institute for Materials Chemistry and Engineering, Fukuoka, Fukuoka-ken, 816-8580, Japan)

Received:2015-10-26 Revised:2016-03-22 Published:2016-12-16 Online:2016-11-23
About author:XU Jian. E-mail: sky3273626@163.com
Supported by:
National Natural Science Foundation of China (11371243);Innovation Major Project of Shanghai Municipal Education Commission (13ZZ068);Key Disciplines of Shanghai Municipality (S30104);Doctoral Fund of Ministry of Education(20113108120019);ARF(2013ZFS6001);SSTC (13521101202)

摘要/Abstract

摘要：

本研究在炭/炭复合材料热解炭基体织构形成与转化的模型基础上, 基于石墨微晶片层的表面结构特点, 建立了蜂窝结构的热解炭沉积表面几何模型, 并运用Monte Carlo方法模拟了在等温等压化学气相渗透(CVI)过程中热解炭基体沉积的动力学过程, 研究了预制体比表面积(A_S/V_R)和入口气体分压对热解炭微观结构的影响。通过数值模拟并结合已公开发表的实验结果发现, 在CVI工艺过程中一定的压力条件下, 通过控制A_S/V_R可以获得不同织构的热解炭, 预制体的A_S/V_R存在两个临界值, 靠近反应器入口处的临界值为1.45 m^-1和8.9 mm^-1, 靠近反应器出口处的临界值为0.3 mm^-1, 当A_S/V_R处于这两个临界值之间时, 系统主要沉积高织构热解炭; 在同一A_S/V_R且压强小于30 kPa的条件下, 通过控制反应气体压强的值也可以得到不同织构的热解炭, 并且压强也存在一个临界值, 当压强大于这个临界值时, 系统主要沉积高织构热解炭。

关键词: Monte Carlo模拟, 炭/炭复合材料, 热解炭, 蜂窝结构, 比表面积, 入口气体分压

Abstract:

Based on the model of pyrolytic carbon matrix texture formation and transformation in CVI for densification of carbon/carbon composites, a new model was constructed to describe the surface of pyrolytic carbon deposited in a honeycomb structure pores. This new model is related with structure characteristics of graphite microchip. The Monte Carlo method is applied to simulate the pyrocarbon deposition kinetics and to analyze the influence of surface area/volume (A_S/V_R) and gas pressure on the texture of pyrocarbon in the process of isothermal-isobaric chemical vapor infiltration (ICVI). According to the numerical simulation results, under certain conditions of pressure, various textured carbon were obtained by controlling A_S/V_R in CVI process. Between two critical values (1.45 mm^-1and 8.9 mm^-1near the inlet, 0.3 mm^-1near the outlet) of A_S/V_R, the high-textured carbon can be obtained. Moreover, if A_S/V_R is certain value and pressure is less than 30 kPa, pyrolytic medium and high textured carbon texture can be obtained as a result of different pressure in CVI process. There is also a critical pressure value and the high-textured carbon can be obtained if the pressure is greater than the critical value.

Key words: Monte Carlo simulation, carbon/carbon composites, pyrolytic carbon, honeycomb structure, surface area/volume, inlet gas pressure

中图分类号:

TQ174

许健, 汤哲鹏, 彭雨晴, 顾传青, Koyo Norinaga, 李爱军. 比表面积与入口气体分压对热解炭微观结构影响的数值模拟研究[J]. 无机材料学报, 2016, 31(12): 1327-1334.

XU Jian, TANG Zhe-Peng, PENG Yu-Qing, GU Chuan-Qing, KOYO Norinaga, LI Ai-Jun. Numerical Simulation for Influence of Surface Area/Volume Ratio and Inlet Gas Pressure on Pyrolytic Carbon Texture[J]. Journal of Inorganic Materials, 2016, 31(12): 1327-1334.

图/表 12

图1 热解炭沉积反应简图

Fig. 1 Simplified reaction scheme for pyrocarbon deposition. GP: gaseous precursors; L: linear small molecule hydrocarbons; A: small aromatic hydrocarbons; PAHs: polycyclic aromatic hydrocarbons

表1 热解炭沉积和织构形成非均相表面反应动力学模型参数设定

Table1 Kinetic parameters of the heterogeneous surface reaction mechanism for carbon deposition and texture formation

k₁/(mol^-1·m³·s^-1)	k₂/s^-1	k₃/(mol^-6·m¹⁸·s^-6)	k₄/s^-1	k₅/s^-1	k₆/s^-1	k₇/(mol^-1·m³·s^-1)
1×10	5×10^-2	4.81×10⁴	2×10^-1	3.86×10^-2	6.57×10^-2	8.96×10

图2 热解炭微观结构的蜂窝结构几何模型点阵图

Fig. 2 Hexagon geometry model diagrammatic sketch for the microstru cture of pyrocarbon

图3 基体表面主要反应物在单位MCS时间内的发生速率 (次/MCS)

Fig. 3 Rates of events happened per MCS on the surface of carbon matrix (times/MCS)

表2 靠近进气口 (No.2) 不同AS/VR值下反应器中C2和Cb的摩尔分数

Table 2 Mole fraction profiles of C2 and C6 in the reactor near the intlet (No.2) with variation of AS/VR

A_S/V_R	0.31	0.79	1.6	2	3.2	4	5	6	7.4
C₂	0.094	0.065	0.033	0.034	0.031	0.025	0.022	0.015	0.015
C₆×100	0.28	0.32	0.41	0.45	0.51	0.50	0.43	0.37	0.31

表3 靠近出气口处 (No.8) 不同AS/VR值下反应器中C2和Cb的摩尔分数

Table 3 Mole fraction profiles of C2 and C6 in the reactor near the outlet (No.8) with variation of AS/VR

A_S/V_R	0.31	0.79	1.6	2	3.2	4	5	6	7.4
C₂	0.12	0.083	0.065	0.062	0.062	0.061	0.061	0.06	0.059
C₆×100	1.12	0.85	0.79	0.78	0.78	0.78	0.77	0.76	0.71

图4 靠近进气口处(No.2)和靠近进气口处(No.8)采样区域归一化C2浓度随AS/VR变化曲线(a)和这两处R值随AS/VR变化曲线

Fig. 4 C2 normalized concentration profiles (a) and R (b) as a function of [AS/VR] ratio at the No.2 sampling area (near the inlet) and the No.8 sampling area (near the outlet)

表4 靠近进气口的No.2采样区域C2归一化浓度a和对应的实验模拟突变点r0

Table 4 Values of C2 normalized and the relative simulated catastrophe points at No.2 sampling area (near the inlet)

a	1	0.691	0.564	0.543	0.479	0.468	0.404	0.372	0.372
r₀	0.156	0.086	0.062	0.058	0.049	0.047	0.046	0.041	0.041

表5 靠近出气口的No.8采样区域C2归一化浓度a和对应的实验模拟突变点r0

Table 5 Values of C2 normalized and the relative simulated catastrophe points at No.8 sampling area (near the outlet)

a	1	0.692	0.525	0.517	0.517	0.508	0.508	0.500	0.492
r₀	0.156	0.086	0.057	0.056	0.056	0.055	0.055	0.054	0.053

图5 靠近进气口的No.2采样区域和靠近出气口的No.8采样区域R和r0随AS/VR值的变化

Fig. 5 R and r0 profiles as a function of [AS/VR] ratio^(a) No.2 sampling area (inlet); (b) No.8 sampling area (outlet)

图6 AS/VR为0.79 mm-1时, No.2和No.8采样区R和r0随压强的变化

Fig. 6 R and r0 profiles as a function of pressure^(a) No.2 sampling area (inlet); (b) No.8 sampling area (outlet); [AS/VR]=0.79 mm-1

图7 AS/VR为3.2 mm-1时, No.2和No.8采样区域R和r0随压强的变化

Fig. 7 R and r0 profiles as a function of pressure^(a) No.2 sampling area (inlet); (b) No.8 sampling area (outlet). [AS/VR]=3.2 mm-1

参考文献 14

[1]	LI H J.Carbon/Carbon composites.New Carbon Materials, 2004 , 16(2): 79-80.
[2]	LUO R Y, LIU T, LI J S,et al. Thermophysical properties of carbon/carbon composites and physical mechanism of thermal expansion and thermal conductivity. Carbon, 2004, 42(14): 2887-2895.
[3]	CHAND S.Review carbon fibers for composites.Journal of Materials Science, 2000, 35(6): 460-463.
[4]	GUELLALI M, OBERACKER R, HOFFMANN M J.Influence of the matrix micro-structure on the mechanical properties of CVI-infiltrated carbon fiber felts.Carbon, 2005, 43: 1954-1960.
[5]	ZHANG DAN, HUANG QING-BO, LI AI-JUN, et al. MC simulations of texture interface formation within pyrocarbon matrix of carbon/carbon composites. Acta Materiae Composite Sinica, 2014(4): 859-865.
[6]	REZNIK B, HÜTTINGER K J. On the terminology for pyrolytic carbon.Carbon, 2002, 40: 621-624.
[7]	REZNIK B, GERTHSEN D.Microscopic study of failure mechanisms in infiltrated carbon fiber felts.Carbon, 2003, 41: 57-69.
[8]	XU WEI, ZHANG ZHONG-WEI, BAI RUI-CHENG,et al. Kinetic modeling of gas-phase reactions for CVD from propane. New Carbon Materials, 2014, 29: 67-77.
[9]	HU Z J, ZHANG W G, HÜTTINGER K J,et al. Influence of pressure,temperature and surface area/volume ratio on the texture of pyrolytic carbon deposited from methane. Carbon, 2003(41): 749-758.
[10]	GÉRARD L V. nteraction between gas diffusion and multistable heterogeneous chemical kinetics in C/C composite processing.The Electrochemical Society, 2001(13): 237-244.
[11]	BOUCHARD E, LAVENAC J, ROUX J C.Pyrocarbon deposits on a graphite surface observed by STM.Adv. Mater.-CVD, 2001, 7(3): 125-130.
[12]	REZNIK B,HÜTTINGER K J. On the terminology for pyrolytic carbon.Carbon, 2002, 40: 621-624.
[13]	DONG G L, HÜTTINGER K J. Consideration of reaction mechanisms leading to pyrolytic carbon of different textures.Carbon, 2002, 40: 2515-2528.
[14]	TANG Z P, LI A J, ZHANG Z,et al. Chemistry and kinetics of heterogeneous reaction mechanism for chemical vapor infiltration of pyrolytic carbon from propane. Industrial Engineering Chemistry Research, 2014, 53(45): 17537-17546.

[1]	周帆, 毕辉, 黄富强. 用稻壳制备亚甲基蓝高吸附容量的超高比表面积活性炭[J]. 无机材料学报, 2021, 36(8): 893-903.
[2]	杨景锋, 王齐华, 王廷梅. 氧化铝气凝胶的合成与性能[J]. 无机材料学报, 2018, 33(3): 259-265.
[3]	王浩, 李琳, 王春雷, 王倩, 梁长海, 王同华. 聚酰亚胺基高比表面活性炭及其电化学性能研究[J]. 无机材料学报, 2017, 32(11): 1181-1187.
[4]	李力成, 何甜甜, 赵学娟, 钱祺, 王磊, 李小保. 多孔钼钛氧化物的自支撑制备及其结构转变[J]. 无机材料学报, 2016, 31(11): 1198-1204.
[5]	赵丹丹, 于彦龙, 高东子, 曹亚安. 金红石二氧化钛纳米片的性质及其光催化活性[J]. 无机材料学报, 2016, 31(1): 1-6.
[6]	盛赵旻, 王樱, 常程康, 刘晓荣, 章冬云, 刘艳. 硫模板法制备多孔石墨纳米笼及其性能表征[J]. 无机材料学报, 2013, 28(12): 1376-1380.
[7]	倪昕晔, 汤晓斌, 林涛, 耿长冉, 蔡雷铭, 顾卫东, 陈达. 医用炭/炭复合材料表面梯度CVD热解炭涂层的摩擦性能研究[J]. 无机材料学报, 2012, 27(5): 545-549.
[8]	高兆辉, 张浩, 曹高萍, 韩敏芳, 杨裕生. 模板法制备介孔VN纳米电极材料及其电容性能[J]. 无机材料学报, 2012, 27(12): 1261-1265.
[9]	李建立, 苏哲安, 张明瑜, 杨鑫, 黄启忠. 高密度预制体制备炭/炭复合材料致密化研究[J]. 无机材料学报, 2011, 26(7): 711-714.
[10]	沈学涛, 李克智, 李贺军, 冯涛, 张磊磊, 王斌. 碳化铪改性炭 / 炭复合材料喉衬的热化学烧蚀[J]. 无机材料学报, 2011, 26(4): 427-432.
[11]	李海亮,李贺军,卢锦花,李克智,姚栋嘉,吴恒. 空气氧化处理的中间相沥青基炭 / 炭复合材料的组织和弯曲性能[J]. 无机材料学报, 2011, 26(2): 197-202.
[12]	杨涛, 祝迎春, 钱霍飞, 袁建辉, 许钫钫. 微米空心碳球串珠结构的制备与形成机理[J]. 无机材料学报, 2011, 26(2): 139-144.
[13]	景介辉, 黄玉东, 刘丽, 姜再兴, 姜波. 炭/炭复合材料纤维束界面层的形成过程[J]. 无机材料学报, 2011, 26(12): 1309-1313.
[14]	邓飞, 曾燮榕, 邹继兆, 黎晓华. 制备温度对热解炭包覆磷酸铁锂/气相生长炭纤维复合正极材料的影响[J]. 无机材料学报, 2011, 26(11): 1141-1146.
[15]	李贺军, 张磊磊, 卢锦花, 李克智, 付前刚, 赵雪妮, 曹盛. 医用炭/炭复合材料人工髋关节的磨损机理研究[J]. 无机材料学报, 2010, 25(9): 999-1002.

比表面积与入口气体分压对热解炭微观结构影响的数值模拟研究

Numerical Simulation for Influence of Surface Area/Volume Ratio and Inlet Gas Pressure on Pyrolytic Carbon Texture

RichHTML

PDF (PC)

可视化

摘要/Abstract

引用本文

使用本文

图/表 12

参考文献 14

相关文章 15

编辑推荐

Metrics

本文评价