孔数与孔厚对多孔板压损系数的影响机理

doi:10.16085/j.issn.1000-6613.2019-0918

摘要/Abstract

摘要：

多孔板作为管道内节流降压或流量测量元件，在减小管道振动、流动噪声及流动压损等方面较之传统的单孔板具有明显优势。影响多孔板压损系数的结构因素主要有开孔等效直径比、孔数及孔板厚度，其中等效直径比的影响规律已为人熟知，而孔数与孔板厚度的影响机理仍不清晰。本文以均匀布孔的多孔板为研究对象，通过数值模拟方法研究了孔数与孔板厚度对多孔板稳定区压损系数的影响机理。结果表明：在相同的孔板厚度下，压损系数随孔数增多而先快速减小后趋于不变，使压损系数达到稳定的临界孔数随管径减小而减少，但临界孔数对应的孔板相对厚度均接近0.5；在相同的孔数下，随孔板相对厚度增大压损系数先快速降低后趋于不变，使压损系数达到稳定的临界相对厚度为0.5~1.0，临界相对厚度随孔数增多而减小；在相同的相对厚度下，压损系数在薄孔板中随孔数增多先减小后增大，而在厚孔板中随孔数增多而单调增大。这说明除等效直径比外，孔数与孔厚均对多孔板压损系数有影响，应在压损系数关联式模型中予以考虑。

关键词: 多孔板, 压损系数, 节流, 流动, 流体动力学

Abstract:

Multi-orifice plate is often used as a throttling or flow measuring component in pipelines, which has obvious advantages in reducing pipe vibration, flow noise and flow pressure loss in comparison with the conventional single-orifice plate. The structural factors being related with the pressure loss coefficient of multi-orifice plates are mainly the equivalent diameter ratio of orifice to pipe, the orifice number and the orifice thickness. The influence of equivalent diameter ratios had been well identified, while the influences of orifice number and orifice thickness are still unclear. In this paper, the effects of changing orifice number or orifice thickness on the pressure loss coefficient of stable region for multi-orifice plates, in which the orifices were arranged in regular triangle layout, were studied by numerical simulation. The results showed that under the same orifice thickness, the pressure loss coefficient decreases rapidly at first and then tends to be a constant with the increase of orifice numbers. The critical orifice number for reaching a stable pressure loss coefficient is declined with the decrease in pipe diameters, while the relative orifice thicknesses corresponding to the critical orifice numbers are close to 0.50 under different pipe diameter. Under the same orifice number, as the relative orifice thickness increases, the pressure loss coefficient decreases rapidly at first and then tends to be a stable value. The critical relative orifice thickness that makes the pressure loss coefficient stable is in the range of 0.5 to 1.0, which decreases as the orifice number increases. Under the same relative orifice thickness, for thin orifice plates the pressure loss coefficient decreases first and then increases with the increase in orifice number, while for thick orifice plates, it increases monotonously with the increase in orifice number. It revealed that, in addition to the equivalent diameter ratio, both the orifice number and the relative orifice thickness should be considered in the pressure loss coefficient correlation for multi-orifice plates because of their considerable influences.

Key words: multi-orifice plate, pressure loss coefficient, throttling, flow, fluid dynamics

中图分类号:

O352

马有福,王凡,吕俊复. 孔数与孔厚对多孔板压损系数的影响机理[J]. 化工进展, 2020, 39(2): 446-452.

Youfu MA,Fan WANG,Junfu LÜ. Influencing mechanism of orifice number and thickness on pressure loss coefficient of multi-orifice plates[J]. Chemical Industry and Engineering Progress, 2020, 39(2): 446-452.

图/表 13

图1 多孔板结构示意图D—管径；d—孔径；t—孔厚；b—孔间距

图2 在不同孔数下孔板的孔分布

表1 在相同β、t下改变n的孔板模拟试件 β=0.40

管径D/mm	孔数n	孔厚t/mm	孔径d/mm	相对厚度t/d	孔间距b/mm
100	1	5	40	0.125	—
	4	5	20	0.250	36
	10	5	12.65	0.395	24
	14	5	10.69	0.468	22.76
	38	5	6.49	0.770	13
	64	5	5	1.000	10.6
50	1	5	20	0.250	—
	4	5	10	0.500	18
	10	5	6.325	0.790	12
	14	5	5.345	0.935	11.38
	38	5	3.245	1.541	6.5
	64	5	2.5	2.000	5.3

表2 在相同t/d下改变n时孔板试件的孔厚t β=0.40

相对厚度t/d	孔厚t/mm
相对厚度t/d	n=1	n=4	n=14	n=38	n=64
0.1	2	1	0.535	0.320	0.250
0.25	5	2.5	1.336	0.800	0.625
0.5	10	5	2.673	1.622	1.250
1.0	20	10	5.345	3.244	2.500
1.5	30	15	8.018	4.866	3.750
2.0	40	20	10.09	6.488	5.000

图3 计算区域及网格

图4 网格独立性验证

图5 相同孔厚下孔数变化对孔板压损系数的影响

图6 相对厚度变化对孔板压损系数的影响

图7 n=1孔板在不同相对厚度下的流动特性

图8 n=14孔板在不同相对厚度下的流动特性

图9 不同相对厚度下压损系数随孔数变化图

图10 t/d=0.1孔板在不同孔数下的流动特性

图11 t/d=2.0孔板在不同孔数下的流动特性

参考文献 17

1	SHAABAN S. On the performance of perforated plate with optimized hole geometry[J]. Flow Measurement and Instrumentation, 2015, 46: 44-50.
2	赵奇, 牛志娟, 杨雪峰. 基于CFD的非标准孔板流量计的数值模拟[J]. 节能技术, 2015, 33(5): 453-456.
	ZHAO Qi, NIU Zhijuan, YANG Xuefeng. Numerical simulation of the non-standard orifice flowmeter based on CFD[J]. Energy Conservation Technology, 2015, 33(5): 453-456.
3	ALY E A, CHONG A, NICOLLEAU F, et al. Experimental study of the pressure drop after fractal-shaped orifices in turbulent pipe flows[J]. Experimental Thermal and Fluid Science, 2010, 34(1): 104-111.
4	程勇, 汪军, 蔡小舒. 低雷诺数的孔板计量数值模拟及其应用[J]. 计量学报, 2005, 26(1): 59-61.
	CHENG Yong, WANG Jun, CAI Xiaoshu. Numerical simulation and application of flow through a pipe orifice at low Reynolds numbers[J]. Acta Metrologica Sinica, 2005, 26(1): 59-61.
5	SHAN F, LIU Z, LIIU W, et al. Effects of the orifice to pipe diameter ratio on orifice flows[J]. Chemical Engineering Science, 2016, 152: 497-506.
6	马太义, 王栋, 张炳东, 等. 多孔板流量测量的实验研究[J]. 核动力工程, 2010(2): 126-130.
	MA Taiyi, WANG Dong, ZHANG Bingdong, et al．Experimental on metering characteristics of multi-hole orifice[J]. Nuclear Power Engineering, 2010(2): 126-130.
7	MALAVASI S, MESSA G, FRATINO U, et al. On the pressure losses through perforated plates[J]. Flow Measurement and Instrumentation, 2012, 28(12): 57-66.
8	HOLT G J, MAYNES D, BLOTTER J. Cavitation at sharp edge multi-hole baffle plates[C]// Proceedings of the ASME 2011 International Mechanical Engineering Congress and Exposition. Denver, USA, 2011: 11-17.
9	ÖZAHI E. An analysis on the pressure loss through perforated plates at moderate Reynolds numbers in turbulent flow regime[J]. Flow Measurement and Instrumentation, 2015, 43: 6-13.
10	ZHAO T Y, MA L. A general structural design methodology for multi-hole orifices and its experimental application[J]. Journal of Mechanical Science and Technology, 2011, 25(9): 2237-2246.
11	焦乾峰, 马有福, 吕俊复, 等. 多孔板压降特性实验与关联式比较[J]. 化工进展, 2018, 37(9): 3320-3325.
	JIAO Qianfeng, MA Youfu, Junfu LÜ, et al. Comparison of experiment with correlation on pressure drop of multi-orifice plates[J]. Chemical Industry and Engineering Progress, 2018, 37(9): 3320-3325.
12	SINGH V K, THARAKAN T J. Numerical simulations for multi-hole orifice flow meter[J]. Flow Measurement and Instrumentation, 2015, 45: 375-383.
13	Inc. Fluent. Fluent 6.3 user’s guide[M]. Ann Arbor: Fluent Inc., 2006．
14	中华人民共和国国家质量监督检验检疫总局, 中国国家标准化管理委员会. 用安装在圆形截面管道中的差压装置测量满管流体流量: GB/T 2624.2—2006[S]. 北京: 中国标准出版社, 2006.
	General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China, Standardization Administration of the People’s Republic of China. Measurement of fluid flow by means of pressure differential devices inserted in circular Orifice plates: GB/T 2624.2—2006[S]. Beijing: Standards Press of China, 2006.
15	蔡振奇. 单孔板气液两相流压降特性及流型可视化实验[D]. 上海: 上海理工大学, 2018.
	CAI Zhenqi. Pressure loss characteristics of gas-liquid two-phase flow in the single-orifice plate and flow patterns visualization experiment[D]. Shanghai: University of Shanghai for Science and Technology, 2018.
16	CHISHOLM D. Two-phase flow in pipelines and heat exchangers[M]. London and New York: G. Godwin in association with Institution of Chemical Engineers, 1983.
17	FINNEMORE E J, FRANZINI J B. 流体力学及其工程应用[M]. 钱翼稷, 译. 北京: 机械工业出版社, 2006.
	FINNEMORE E J, FRANZINI J B. Fluid mechanics with engineering applications[M]. Qian Yiji, trans. Beijing: China Machine Press, 2006.

[1]	黄益平, 李婷, 郑龙云, 戚傲, 陈政霖, 史天昊, 张新宇, 郭凯, 胡猛, 倪泽雨, 刘辉, 夏苗, 主凯, 刘春江. 三级环流反应器中气液流动与传质规律[J]. 化工进展, 2023, 42(S1): 175-188.
[2]	赵晨, 苗天泽, 张朝阳, 洪芳军, 汪大海. 负压状态窄缝通道乙二醇水溶液传热特性[J]. 化工进展, 2023, 42(S1): 148-157.
[3]	陈林, 徐培渊, 张晓慧, 陈杰, 徐振军, 陈嘉祥, 密晓光, 冯永昌, 梅德清. 液化天然气绕管式换热器壳侧混合工质流动及传热特性[J]. 化工进展, 2023, 42(9): 4496-4503.
[4]	罗成, 范晓勇, 朱永红, 田丰, 崔楼伟, 杜崇鹏, 王飞利, 李冬, 郑化安. 中低温煤焦油加氢反应器不同分配器中液体分布的CFD模拟[J]. 化工进展, 2023, 42(9): 4538-4549.
[5]	孙征楠, 李洪晶, 荆国林, 张福宁, 颜飚, 刘晓燕. EVA及其改性聚合物在原油降凝剂领域的应用[J]. 化工进展, 2023, 42(6): 2987-2998.
[6]	郭文杰, 翟玉玲, 陈文哲, 申鑫, 邢明. Al₂O₃-CuO/水混合纳米流体对流传热性能及热经济性分析[J]. 化工进展, 2023, 42(5): 2315-2324.
[7]	王文昊, 何立东, 王学志, 闫泽, 贾兴运, 刘春瑞. 偏心工况下梳齿、蜂窝与蜂窝-梳齿密封的泄漏特性[J]. 化工进展, 2023, 42(4): 1698-1707.
[8]	张成松, 张静, 龚斌, 李明洋, 袁佳新, 李宏业. 自吸射流柔性搅拌桨振动特性[J]. 化工进展, 2023, 42(4): 1728-1738.
[9]	刘佳, 梁德青, 李君慧, 林德才, 吴思婷, 卢富勤. 油水体系水合物浆液流动保障研究进展[J]. 化工进展, 2023, 42(4): 1739-1759.
[10]	谢迎春, 王倩倩, 马永丽, 孙国强, 刘明言. 超声波与紫外线耦合脱气杀菌[J]. 化工进展, 2023, 42(3): 1629-1637.
[11]	王唯, 张东旭, 李遵照, 王晓霖, 黄启玉. 油包水乳状液体系中水合物生长行为研究进展[J]. 化工进展, 2023, 42(3): 1155-1166.
[12]	闫兴清, 戴行涛, 喻健良, 李岳, 韩冰, 胡军. 高压氢气泄漏射流研究进展[J]. 化工进展, 2023, 42(3): 1118-1128.
[13]	罗小平, 樊鹏, 周建阳, 王梦圆. 不同波纹壁面微细通道沸腾曲线及沸腾起始点研究[J]. 化工进展, 2023, 42(3): 1228-1239.
[14]	侯婉, 陈汇龙, 程谦, 陈英健, 卫泽鹏, 赵斌娟. 高温密封润滑膜汽液固流动特性数值计算分析[J]. 化工进展, 2023, 42(2): 699-710.
[15]	刘君康, 王宏超, 熊通, 晏刚, 郭宁, 刘睿. 热泵空调翅片管换热器流路优化研究进展[J]. 化工进展, 2023, 42(1): 107-117.