| Citation: |
CHEN Yongping，LIU Ronghua，CHEN Shiqiang，et al. Energy transfer process and evolution characteristics in impeller of contra-rotating axial fan[J]. Coal Science and Technology，2024，52（11）：356−367. DOI: 10.12438/cst.2023-1463
|
Energy is transferred to the airflow during the rotation of impeller. In engineering, the efficient energy conversion is a key issue. Mastering the energy transfer process in impeller is the premise and basis for realizing efficient energy conversion. In order to clarify the energy transfer mechanism in impeller of contra-rotating axial fan, the internal flow field in impeller was obtained by numerical simulation and experiment. Based on the turbomachine energy conversion theory, the evolution characteristics of parameters such as flow angle, axial velocity and local theory total pressure rise were analyzed, and the laws of energy distribution and flow loss process in impeller were clarified. The results show that the efficiency of front impeller is significantly higher than that of the rear impeller when the flow rate is greater than 0.7 QBEP (QBEP is flow rate at the best efficiency point). When Q=1.0 QBEP, the efficiency difference between the two-stage impellers is about 26.5%, and the efficiency difference is as high as 66.6% when the flowrate increases to 1.22 QBEP, which indicate that the low efficiency of the rear impeller is the main reason for the efficiency reduction of the fan. In the streamwise location, the flow loss of the rear impeller is concentrated within STL=0−0.3 (STL represents the dimensionless distance from the inlet to outlet of the impeller in the flow direction), and reducing the flow loss in this region is the key to improve the efficiency of rear impeller. The hump characteristic of actual total pressure rise curve is the result of the combined effect of theory total pressure rise and flow loss, but mainly related to the theory total pressure rise at the outlet of front impeller and inlet of rear impeller. The sharp decrease or increase in flow angle at the spanwise direction is the main cause of a significant decrease in axial velocity, which in turn leads to backflow in the inlet and outlet of the front impeller and inlet of the rear impeller within SPN=0.8−1.0 (SPN represents the dimensionless distance from the hub to shroud of the impeller in the spanwise direction), and ultimately affects the theory total pressure rise in impeller. Therefore, the flow angle and axial velocity jointly affect the energy evolution law in impeller. The local theory total pressure rise is greatly improved in the middle region of the impeller, while the change in the inlet and outlet region is negligible. The significant increase growth rate of local theory total pressure rise is the key factor determining the theory total pressure rise of the impeller.
| [1] |
周福宝,辛海会,魏连江,等. 矿井智能通风理论与技术研究进展[J]. 煤炭科学技术,2023,51(1):313−328.
ZHOU Fubao,XIN Haihui,WEI Lianjiang,et al. Research progress of mine intelligent ventilation theory and technology[J]. Coal Science and Technology,2023,51(1):313−328.
|
| [2] |
张庆华,姚亚虎,赵吉玉. 我国矿井通风技术现状及智能化发展展望[J]. 煤炭科学技术,2020,48(2):97−103.
ZHANG Qinghua,YAO Yahu,ZHAO Jiyu. Status of mine ventilation technology in China and prospects for intelligent development[J]. Coal Science and Technology,2020,48(2):97−103.
|
| [3] |
陈庆光,徐延辉,郭武,等. 轴向间距对FBCDZ-10-No20型对旋风机失速过程的影响[J]. 煤炭科学技术,2023,51(6):229−236.
CHEN Qingguang,XU Yanhui,GUO Wu,et al. Influence of axial spacing on stall development of FBCDZ-10-No20 mode contra-rotating fan[J]. Coal Science and Technology,2023,51(6):229−236.
|
| [4] |
AI Z J,QIN G L,LIN J X,et al. Variable-speed method for improving the performance of a mine counter-rotating fan[J]. Energy Science & Engineering,2020,8(7):2412−2425.
|
| [5] |
HAO H Q,JIANG S G,WU Z Y,et al. Experimental study on precise control air quantity on demand by the cooperation of multiple main fans in mine[J]. Journal of Cleaner Production,2023,414:137626. doi: 10.1016/j.jclepro.2023.137626
|
| [6] |
孙晓波,孟大伟,杨小妮. 对旋风机电动机变极调速控制与节能分析[J]. 电机与控制学报,2019,23(11):60−66.
SUN Xiaobo,MENG Dawei,YANG Xiaoni. Pole-changing control of motors and its energy saving of contra-rotating axial-flow fan[J]. Electric Machines and Control,2019,23(11):60−66.
|
| [7] |
陈世强,成剑林,冯进,等. 主扇扩散器出口速度分布的数值模拟与实验研究[J]. 中国安全科学学报,2008,18(8):32−36. doi: 10.3969/j.issn.1003-3033.2008.08.005
CHEN Shiqiang,CHENG Jianlin,FENG Jin,et al. Numerical simulation and experimental research on the velocity distribution in outlet of main fan diffusers[J]. China Safety Science Journal (CSSJ),2008,18(8):32−36. doi: 10.3969/j.issn.1003-3033.2008.08.005
|
| [8] |
金永平,刘德顺,文泽军. 矿用对旋式轴流通风机前后两级叶片弯掠参数优化设计[J]. 煤炭学报,2010,35(10):1754−1759.
JIN Yongping,LIU Deshun,WEN Zejun. Optimization design for skew and sweep parameters of mine contra-rotating axial fan two-stage blades[J]. Journal of China Coal Society,2010,35(10):1754−1759.
|
| [9] |
孙文龙,方祥军. 对旋风机叶片造型优化对气动特性的影响[J]. 工程热物理学报,2018,39(6):1251−1257.
SUN Wenlong,FANG Xiangjun. Influence of blade structure optimization on the aerodynamic characteristics for counter-rotating fan[J]. Journal of Engineering Thermophysics,2018,39(6):1251−1257.
|
| [10] |
YE X M,ZHENG N,HU J M,et al. Numerical investigation of the benefits of serrated Gurney flaps on an axial flow fan[J]. Energy,2022,252:124072. doi: 10.1016/j.energy.2022.124072
|
| [11] |
YE X M,ZHANG J K,LI C X. Effect of blade tip pattern on performance of a twin-stage variable-pitch axial fan[J]. Energy,2017,126:535−563. doi: 10.1016/j.energy.2017.03.057
|
| [12] |
杨天康,叶学民,林卿,等. 叶顶开槽:小翼结构对提升轴流风机性能影响的数值研究[J]. 热能动力工程,2023,38(7):36−43.
YANG Tiankang,YE Xuemin,LIN Qing,et al. Numerical study on influence of blade tip slot-winglet pattern on performance improvement of an axial fan[J]. Journal of Engineering for Thermal Energy and Power,2023,38(7):36−43.
|
| [13] |
张永建,徐晓,陈庆光,等. 轴向间距对矿用对旋式通风机性能的影响[J]. 煤炭学报,2011,36(7):1217−1221.
ZHANG Yongjian,XU Xiao,CHEN Qingguang,et al. Effects of axial gap on contra-rotating mine fan’s performance[J]. Journal of China Coal Society,2011,36(7):1217−1221.
|
| [14] |
陈世强,王海桥,杨超,等. 变频矿用主通风机流量比与功率比的非等比特性实验研究[J]. 湖南科技大学学报(自然科学版),2016,31(2):1−7.
CHEN Shiqiang,WANG Haiqiao,YANG Chao,et al. Experimental investigation of a mine main fan with variable frequency adjustment and the non-equal law between flowrate-ratio and power-ratio[J]. Journal of Hunan University of Science & Technology (Natural Science Edition),2016,31(2):1−7.
|
| [15] |
TIAN F,WANG H Q,CHEN S Q,et al. Energy efficiency overestimated by classic affinity laws:relation between volumetric flow rate and static pressure of an axial mine fan adjusted by a variable frequency driver[J]. Mining Technology,2019,128(3):186−191. doi: 10.1080/25726668.2019.1631623
|
| [16] |
温嘉斌,和海波. 对旋轴流通风机流场预测及两级电机功率匹配研究[J]. 电工技术学报,2015,30(1):105−111. doi: 10.3969/j.issn.1000-6753.2015.01.014
WEN Jiabin,HE Haibo. Flow field estimation of counter-rotating axial flow fan and power matching research of two motors[J]. Transactions of China Electrotechnical Society,2015,30(1):105−111. doi: 10.3969/j.issn.1000-6753.2015.01.014
|
| [17] |
陈庆光,邹璐瑶,李哲,等. 进气型式对压入式矿用对旋主通风机内部流动及性能的影响[J]. 煤炭工程,2020,52(4):171−176.
CHEN Qingguang,ZOU Luyao,LI Zhe,et al. Effect of intake type on internal flow and performance of mining contra-rotating main fan for forced ventilation[J]. Coal Engineering,2020,52(4):171−176.
|
| [18] |
陈庆光,邹璐瑶,李哲,等. 畸变进气条件下压入式矿用对旋主通风机失速机理研究[J]. 机械科学与技术,2021,40(5):670−677.
CHEN Qingguang,ZOU Luyao,LI Zhe,et al. Study on stall mechanism of mining contra-rotating main fan for forced type ventilation under distortion air intake condition[J]. Mechanical Science and Technology for Aerospace Engineering,2021,40(5):670−677.
|
| [19] |
MANAS M P,PRADEEP A M. Influence of distorted inflows on the performance of a contra-rotating fan[J]. The Aeronautical Journal,2021,125(1286):702−719. doi: 10.1017/aer.2020.120
|
| [20] |
SHIGEMITSU T,FUKUTOMI J,OKABE Y,et al. Performance and flow condition of contra-rotating small-sized axial fan at partial flow rate[J]. International Journal of Fluid Machinery and Systems,2010,3(4):271−278. doi: 10.5293/IJFMS.2010.3.4.271
|
| [21] |
艾子健,吴龙,高浩. 对旋风机两级叶轮等功率R2变转速试验研究[J]. 流体机械,2019,47(3):1−5.
AI Zijian,WU Long,GAO Hao. Experimental study on the R2 speed matching with equal power for the two rotors of the counter-rotating fan[J]. Fluid Machinery,2019,47(3):1−5.
|
| [22] |
JUNG J H,JOO W G. The effect of the entrance hub geometry on the efficiency in an axial flow fan[J]. International Journal of Refrigeration,2019,101:90−97. doi: 10.1016/j.ijrefrig.2019.02.026
|
| [23] |
JUNG J H,JOO W G. Effect of tip clearance,winglets,and shroud height on the tip leakage in axial flow fans[J]. International Journal of Refrigeration,2018,93:195−204.
|
| [24] |
TIAN C Y,LIU X M,WANG J H,et al. Effects of bionic blades inspired by the butterfly wing on the aerodynamic performance and noise of the axial flow fan used in air conditioner[J]. International Journal of Refrigeration,2022,140:17−28. doi: 10.1016/j.ijrefrig.2022.04.018
|
| [25] |
WANG K,JU Y P,ZHANG C H. Aerodynamic optimization of forward-curved blade centrifugal fan characterized by inclining bionic volute tongue[J]. Structural and Multidisciplinary Optimization,2021,63(5):2493−2507. doi: 10.1007/s00158-020-02801-2
|
| [26] |
WHITE F M. Fluid mechanics[M]. New York:McGraw-Hill,2011:764−766.
|
| [27] |
MUNSON B R,DONALD F Y,OKIISHI T H,et al. Fundamentals of Fluid Mechanics[M]. Hoboken:John Wiley & Sons,2009:647−652.
|
Supported by: Beijing Renhe Information Technology Co., Ltd. 
DownLoad: