不同进气方式下气力提升泵水力特性理论模型与验证
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摘要
为了深入研究气力提升泵的提升性能,该文首先进行了理论分析,建立了适用于不同进气方式的气力提升模型。同时通过改变进气面积与气孔分布方式进行试验研究,试验结果与理论分析结果吻合较好,该模型在一定范围内能够较好地预测提升泵的提升流量;并且根据试验结果,进一步分析了不同进气方式对气力提升泵的液体提升量与提升效率的影响规律。结果表明:首先,7 mm方形喷嘴进气方式下,随着气流量的增加,提升液体流量先较快增加,之后上升趋势逐渐变缓,提升效率先迅速升高,达到峰值后又下降,而沉浸比升高会使峰值效率提高。其次,沉浸比为0.5时,不同进气面积下,较小的进气面积导致提升效率降低;在相同进气面积下,不同的气孔排布方式对提升液体流量与提升效率的影响并不明显。再次,当管内流型接近弹状流型时,提升效率较高,稳定性较好;在环状流下,提升泵的效率最低,稳定性差。
Air lift pump is widely applied in oil and ore exploitation, due to its simple structure, high practicability and other prominent advantages. However, the pump is not fully applied because of its low efficiency. To investigate the lift performance of air-lift pump intensively, a theoretical analysis was carried out to and a theoretical model of air-lift for different inlet methods was established in present paper. At the same time, to test the theoretical model and better understand its operating principle, in this paper, the performance of air lift pump was investigated by changing air inlet area and pore distribution pattern in the air lift pump facility. In the experiment, the air, supplied from air compressor, was injected into the riser pipe by nozzle, in order to drive the liquid to move upward in the pipe. Air and water were separated from the gas-liquid separation tank in the top of the riser pipe, and the separated water dropped into the water measuring tank(bucket). In the experimental test, stopwatch recorded the working time of air lift pump, and electronic scale weighed the water from the bucket. The air nozzle selected 3 kinds of injection areas, i.e. 25, 50 and 100 mm~2, and for each injection area, 3 injection methods were adopted. Various submergence ratios(0.4-0.9) were investigated, while the range of the air flow rate was from 0 to 16.0 m~3/h. For each air injection method and submergence ratio, the air flow rate varied, the corresponding flow rate of water was measured, and the promoting efficiency was calculated. We used high-speed camera to capture the flow regime in the tube to deeply discuss the relationship between air lift capacity and the two-phase flow characteristics. By analyzing the experimental data, the results are obtained as follows: Firstly, for the air injection method of 7 mm square nozzle, with the increase of air flow rate, the fluid flow rate of pump increases quickly, and then rises slowly, and the efficiency of pump goes up rapidly to the peak, and then decreases continuously. With the submergence ratio increasing, the peak of promoting efficiency becomes bigger, and the corresponding air flow rate is smaller. Secondly, for the submergence ratio of 0.5, when the air injection area is 25 mm~2, the liquid volume flow rate is significantly higher than other areas of nozzle. For the different air injection areas, the smaller area will cause higher pipeline pressure, which helps to lift liquid but decrease promoting efficiency of pump. For the same air injection area, there is little difference in the pump performance with different pore distribution patterns. Thirdly, in the gas-liquid two-phase flow of riser pipe, we observe 4 kinds of flow patterns, i.e. bubbly, slug, churning, and annular flow. In the bubbly and slug flow, there is little noise in the experiment, but in the churning and annular flow, the noise increases gradually. Near the slug flow, the promoting efficiency reaches the highest point, and the stability is good. In the annular flow, the promoting efficiency reaches the lowest point, and the stability is bad. Finally, the experimental results are compared with the theoretical values, while the experimental results agreed well with the theoretical analysis results in present paper, and the model could predict the liquid flow rate of air-lift pump better in a certain range. Near the slug flow, the theoretical model preferably predicts the performance characteristics of air lift pump, and the calculation results have a good agreement with experimental results. In the other flow patterns, the experimental data and the simulation results have some deviation. The cause is that the theoretical model adopts the slip ration formula of Griffith and Wallis, which is only suitable for the slug flow. In the follow-up work, the theoretical model should be improved. In a word, this study provides an important reference for deeply understanding the performance characteristics of air lift pump.
Air lift pump is widely applied in oil and ore exploitation, due to its simple structure, high practicability and other prominent advantages. However, the pump is not fully applied because of its low efficiency. To investigate the lift performance of air-lift pump intensively, a theoretical analysis was carried out to and a theoretical model of air-lift for different inlet methods was established in present paper. At the same time, to test the theoretical model and better understand its operating principle, in this paper, the performance of air lift pump was investigated by changing air inlet area and pore distribution pattern in the air lift pump facility. In the experiment, the air, supplied from air compressor, was injected into the riser pipe by nozzle, in order to drive the liquid to move upward in the pipe. Air and water were separated from the gas-liquid separation tank in the top of the riser pipe, and the separated water dropped into the water measuring tank(bucket). In the experimental test, stopwatch recorded the working time of air lift pump, and electronic scale weighed the water from the bucket. The air nozzle selected 3 kinds of injection areas, i.e. 25, 50 and 100 mm~2, and for each injection area, 3 injection methods were adopted. Various submergence ratios(0.4-0.9) were investigated, while the range of the air flow rate was from 0 to 16.0 m~3/h. For each air injection method and submergence ratio, the air flow rate varied, the corresponding flow rate of water was measured, and the promoting efficiency was calculated. We used high-speed camera to capture the flow regime in the tube to deeply discuss the relationship between air lift capacity and the two-phase flow characteristics. By analyzing the experimental data, the results are obtained as follows: Firstly, for the air injection method of 7 mm square nozzle, with the increase of air flow rate, the fluid flow rate of pump increases quickly, and then rises slowly, and the efficiency of pump goes up rapidly to the peak, and then decreases continuously. With the submergence ratio increasing, the peak of promoting efficiency becomes bigger, and the corresponding air flow rate is smaller. Secondly, for the submergence ratio of 0.5, when the air injection area is 25 mm~2, the liquid volume flow rate is significantly higher than other areas of nozzle. For the different air injection areas, the smaller area will cause higher pipeline pressure, which helps to lift liquid but decrease promoting efficiency of pump. For the same air injection area, there is little difference in the pump performance with different pore distribution patterns. Thirdly, in the gas-liquid two-phase flow of riser pipe, we observe 4 kinds of flow patterns, i.e. bubbly, slug, churning, and annular flow. In the bubbly and slug flow, there is little noise in the experiment, but in the churning and annular flow, the noise increases gradually. Near the slug flow, the promoting efficiency reaches the highest point, and the stability is good. In the annular flow, the promoting efficiency reaches the lowest point, and the stability is bad. Finally, the experimental results are compared with the theoretical values, while the experimental results agreed well with the theoretical analysis results in present paper, and the model could predict the liquid flow rate of air-lift pump better in a certain range. Near the slug flow, the theoretical model preferably predicts the performance characteristics of air lift pump, and the calculation results have a good agreement with experimental results. In the other flow patterns, the experimental data and the simulation results have some deviation. The cause is that the theoretical model adopts the slip ration formula of Griffith and Wallis, which is only suitable for the slug flow. In the follow-up work, the theoretical model should be improved. In a word, this study provides an important reference for deeply understanding the performance characteristics of air lift pump.
引文
[1]Stepanoff A J.Thermodynamic theory of the air lift[J].Trans.ASME 1929,51:49.
[2]Stenning A H,Martin C B.An analytical and experimental study of air-lift pump performance[J].J.Eng.Gas Turbines Power,1968,90(2):106-110.
[3]Kato H,Tamiya S,Miyazawa T.A study of air-lift pump for solid particles and its application to marine engineering[J].JSME.1975,18(117):286-294.
[4]Weber M,Dedegil Y.Transport of solids according to the air-lift principle[C]//Proceedings of 4th International Conference on the Hydraulic Transport of Solids in Pipes.Alberta,Canada,1976,1-23,93-94.
[5]Geest S,Aoliemans R V,Ellepola J H.Comparison of different air injection methods to improve gas-lift performance[J].BHR Group Multiphase,2001,1:363-378.
[6]Kumar E A,Kumar K R V,Ramayya A V.Augmentation of airlift pump performance with tapered upriser pipe-an experimental study[J].IE(I)Journal.MC,2003,84(10):114-119.
[7]Kassab S Z,Kandil H A,WARDA H A,et al.Experimental and analytical investigations of airlift pumps operating in three-phase flow[J].Chemical Engineering Journal,2007,131(1):273-281.
[8]Cho N C,Hwang I J,Moon L C,et al.An experimental study on the airlift pump with air jet nozzle and booster pump[J].Journal of Environmental Sciences Supplement,2009,21:19-23.
[9]Esen II.Experimental investigation of a rectangular air-lift pump[J].Advances in Civil Engineering,2010,11(1):1-5.
[10]Keng W C,Malcolm M.Analysis and modeling of water based bubble pump at atmospheric pressure[J].International Journal of Refrigeration,2013,36:1521-1528.
[11]Hanafizadeh P,Saidi M H,Karimi A,et al.A effect of bubble size and angle of tapering up-riser pipe on the performance of airlift pumps[J].Particulate Science and Technology,2010,28:332-347.
[12]Charalampos T,Eeftherios G.Two-phase flow pattern transitions of short airlift pumps[J].Journal of Hydraulic Research,2010,48(5):680-685.
[13]Charalampoms T,Eeftherios G.Pressure behavior in riser tube of a short airlift pump[J].Journal of Hydraulic Research,2010,48(1):65-73.
[14]Dhotre M T,Joshi J B.Design of a gas distributor:Threedimensional CFD simulation of a coupled system consisting of a gas chamber and a bubble column[J].Chemical Engineering Journal,2007,125:149-163.
[15]Sadek Z,Hamdy A,Hassan A,et al.Air-lift pumps characteristics under two-phase flow conditions[J].International Journal of Heat and Fluid Flow,2009,30:88-98.
[16]Pedram H,Soheil G,Mohammad H.Visual technique for detection of gas-liquid two-phase flow regime in the airlift pump[J].Journal of Petroleum Science and Engineering,2011,75:327-335.
[17]江涛,徐明昌,曾智,等.大水面网箱收集养殖废弃物及水系统处理研发[J].农业工程学报,2014,30(20):211-218.Jiang Tao,Xu Mingchang,Zeng Zhi,et al.Development of waste collection and water treatment system of cage culture in open waters[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2014,30(20):211-218.(in Chinese with English abstract)
[18]Hanafizadeh P,Karimi A,Saidi M H.Effect of step geometry on the performance of the airlift pump[J].Fluid Mechanics Research,2011,38(5):387-408.
[19]Zuo J L,Tian W X,Chen R H,et al.Research on enhancement of natural circulation capability in lead-bismuth alloy cooled reactor by using gas-lift pump[J].Nuclear Engineering and Design,2013,263:1-9.
[20]左娟莉,田文喜,秋穗正,等.铅铋合金冷却反应堆内气泡提升泵提升自然循环能力的理论研究[J].原子能科学技术,2013,47(7):1155-1161.Zuo Juanli,Tian Wenxi,Qiu Suizheng,et al.Research on enhancement of natural circulation capability in lead-bismuth alloy cooled reactor by using gas-lift pump[J].Atomic Energy Science and Technology,2013,47(7):1155-1161.(in Chinese with English abstract)
[21]Zuo J L,Tian W X,Qiu S Z,et al.Transient safety for analysis driven system with gas-lift pump[C]//International Embedded Topical Meeting on Advances in Thermal Hydraulics-2014,Reno,NV,USA,2014.
[22]魏海,谢焕雄,胡志超,等.花生荚果气力输送设备参数优化与试验[J].农业工程学报,2016,32(2):6-12.Wei Hai,Xie Huanxiong,Hu Zhichao,et al.Parameter optimization and test of pneumatic conveying equipment for peanut pods[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2016,32(2):6-12.(in Chinese with English abstract)
[23]孙波,孙立成,刘靖宇,等.竖直较大管径内气液两相流截面含气率实验研究[J].水动力学研究与进展,2012,27(1):1-6.Sun Bo,Sun Licheng,Liu Jingyu,et al.Study on void fraction of vertical gas-liquid two-phase flow in a relatively large diameter pipe[J].Chinese Journal of Hydrodynamics,2012,27(1):1-6.(in Chinese with English abstract)
[24]刘曼.局部弯曲对气力提升性能的影响规律及管内流型分析[D].株洲:湖南工业大学,2014.Liu Man.Effect of Local Pipe Bends on Airlift Pump Performance and Study of Flow Pattern[D].Zhuzhou:Hunan University of Technology,2014.(in Chinese with English abstract)
[25]王孝红.气力提升法在水电站淤沙处理中的运用[J].云南水力发电,2015,31(1):101-103.Wang Xiaohong.A Effective method for silt sedimentation handling in practices[J].Yunnan Water Power,2015,31(1):101-103.(in Chinese with English abstract)
[26]Griffith P,Wallis G B.Two-Phase slug flow[J].ASME J.Heat Trans.,1961,83:307.
[27]Parker G J.The effect of footpiece design on the performance of a small air lift pump[J].International Journal of Heat and Fluid Flow,1980,4(2):245-252.
[28]Colebrook C F.Turbulent flow in pipes,with particular reference to the transition region between the smooth and rough pipe laws[J].J.Inst.Civ.Eng.,London,1939,11:133-156.
[29]Haaland S E.Simple and explicit formulas for the friction factor in turbulent flow[J].J.Fluids Eng.,1983,103:89-90.
[30]Nicklin D J.The air lift pump theory and optimization[J].ICHE14,1963,29-39.
[2]Stenning A H,Martin C B.An analytical and experimental study of air-lift pump performance[J].J.Eng.Gas Turbines Power,1968,90(2):106-110.
[3]Kato H,Tamiya S,Miyazawa T.A study of air-lift pump for solid particles and its application to marine engineering[J].JSME.1975,18(117):286-294.
[4]Weber M,Dedegil Y.Transport of solids according to the air-lift principle[C]//Proceedings of 4th International Conference on the Hydraulic Transport of Solids in Pipes.Alberta,Canada,1976,1-23,93-94.
[5]Geest S,Aoliemans R V,Ellepola J H.Comparison of different air injection methods to improve gas-lift performance[J].BHR Group Multiphase,2001,1:363-378.
[6]Kumar E A,Kumar K R V,Ramayya A V.Augmentation of airlift pump performance with tapered upriser pipe-an experimental study[J].IE(I)Journal.MC,2003,84(10):114-119.
[7]Kassab S Z,Kandil H A,WARDA H A,et al.Experimental and analytical investigations of airlift pumps operating in three-phase flow[J].Chemical Engineering Journal,2007,131(1):273-281.
[8]Cho N C,Hwang I J,Moon L C,et al.An experimental study on the airlift pump with air jet nozzle and booster pump[J].Journal of Environmental Sciences Supplement,2009,21:19-23.
[9]Esen II.Experimental investigation of a rectangular air-lift pump[J].Advances in Civil Engineering,2010,11(1):1-5.
[10]Keng W C,Malcolm M.Analysis and modeling of water based bubble pump at atmospheric pressure[J].International Journal of Refrigeration,2013,36:1521-1528.
[11]Hanafizadeh P,Saidi M H,Karimi A,et al.A effect of bubble size and angle of tapering up-riser pipe on the performance of airlift pumps[J].Particulate Science and Technology,2010,28:332-347.
[12]Charalampos T,Eeftherios G.Two-phase flow pattern transitions of short airlift pumps[J].Journal of Hydraulic Research,2010,48(5):680-685.
[13]Charalampoms T,Eeftherios G.Pressure behavior in riser tube of a short airlift pump[J].Journal of Hydraulic Research,2010,48(1):65-73.
[14]Dhotre M T,Joshi J B.Design of a gas distributor:Threedimensional CFD simulation of a coupled system consisting of a gas chamber and a bubble column[J].Chemical Engineering Journal,2007,125:149-163.
[15]Sadek Z,Hamdy A,Hassan A,et al.Air-lift pumps characteristics under two-phase flow conditions[J].International Journal of Heat and Fluid Flow,2009,30:88-98.
[16]Pedram H,Soheil G,Mohammad H.Visual technique for detection of gas-liquid two-phase flow regime in the airlift pump[J].Journal of Petroleum Science and Engineering,2011,75:327-335.
[17]江涛,徐明昌,曾智,等.大水面网箱收集养殖废弃物及水系统处理研发[J].农业工程学报,2014,30(20):211-218.Jiang Tao,Xu Mingchang,Zeng Zhi,et al.Development of waste collection and water treatment system of cage culture in open waters[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2014,30(20):211-218.(in Chinese with English abstract)
[18]Hanafizadeh P,Karimi A,Saidi M H.Effect of step geometry on the performance of the airlift pump[J].Fluid Mechanics Research,2011,38(5):387-408.
[19]Zuo J L,Tian W X,Chen R H,et al.Research on enhancement of natural circulation capability in lead-bismuth alloy cooled reactor by using gas-lift pump[J].Nuclear Engineering and Design,2013,263:1-9.
[20]左娟莉,田文喜,秋穗正,等.铅铋合金冷却反应堆内气泡提升泵提升自然循环能力的理论研究[J].原子能科学技术,2013,47(7):1155-1161.Zuo Juanli,Tian Wenxi,Qiu Suizheng,et al.Research on enhancement of natural circulation capability in lead-bismuth alloy cooled reactor by using gas-lift pump[J].Atomic Energy Science and Technology,2013,47(7):1155-1161.(in Chinese with English abstract)
[21]Zuo J L,Tian W X,Qiu S Z,et al.Transient safety for analysis driven system with gas-lift pump[C]//International Embedded Topical Meeting on Advances in Thermal Hydraulics-2014,Reno,NV,USA,2014.
[22]魏海,谢焕雄,胡志超,等.花生荚果气力输送设备参数优化与试验[J].农业工程学报,2016,32(2):6-12.Wei Hai,Xie Huanxiong,Hu Zhichao,et al.Parameter optimization and test of pneumatic conveying equipment for peanut pods[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2016,32(2):6-12.(in Chinese with English abstract)
[23]孙波,孙立成,刘靖宇,等.竖直较大管径内气液两相流截面含气率实验研究[J].水动力学研究与进展,2012,27(1):1-6.Sun Bo,Sun Licheng,Liu Jingyu,et al.Study on void fraction of vertical gas-liquid two-phase flow in a relatively large diameter pipe[J].Chinese Journal of Hydrodynamics,2012,27(1):1-6.(in Chinese with English abstract)
[24]刘曼.局部弯曲对气力提升性能的影响规律及管内流型分析[D].株洲:湖南工业大学,2014.Liu Man.Effect of Local Pipe Bends on Airlift Pump Performance and Study of Flow Pattern[D].Zhuzhou:Hunan University of Technology,2014.(in Chinese with English abstract)
[25]王孝红.气力提升法在水电站淤沙处理中的运用[J].云南水力发电,2015,31(1):101-103.Wang Xiaohong.A Effective method for silt sedimentation handling in practices[J].Yunnan Water Power,2015,31(1):101-103.(in Chinese with English abstract)
[26]Griffith P,Wallis G B.Two-Phase slug flow[J].ASME J.Heat Trans.,1961,83:307.
[27]Parker G J.The effect of footpiece design on the performance of a small air lift pump[J].International Journal of Heat and Fluid Flow,1980,4(2):245-252.
[28]Colebrook C F.Turbulent flow in pipes,with particular reference to the transition region between the smooth and rough pipe laws[J].J.Inst.Civ.Eng.,London,1939,11:133-156.
[29]Haaland S E.Simple and explicit formulas for the friction factor in turbulent flow[J].J.Fluids Eng.,1983,103:89-90.
[30]Nicklin D J.The air lift pump theory and optimization[J].ICHE14,1963,29-39.