摇摆状态下垂直管内降膜吸收传热传质理论及实验研究
|
摘要
将吸收式制冷系统用于远洋渔船的海产品冷冻保鲜是解决我国远洋渔船污染环境、浪费能源的重要途径之一。而了解吸收式制冷系统中最重要的组成部分——吸收器在船舶的颠簸摇摆状态下的性能变化是吸收式制冷系统能否用于渔船的关键。本文主要研究并模拟了摇摆状态下管内降膜吸收过程中的液膜流动流场，为进一步研究摇摆状态下吸收器吸收性能的变化打下了必要的基础。
本文首先研究了船舶在海洋中的运动，建立了船舶摇摆运动的简化物理模型和数学模型，得到了运动附加力的表达式；并在此基础上将吸收管的运动附加力表达式代入静止状态下液膜流动的数学模型中，即得到了摇摆状态下液膜流动的数学模型；然后对液膜流动的数学模型进行了简化，在假定了速度分布的条件下，得出了液膜流动的积分方程，经过以上简化就将求解三维问题转化成为求解二维问题；将积分方程离散后用数值计算的方法模拟了整个流场。
为验证理论模型的可靠性并进一步深入了解实际摇摆降膜吸收过程中热、质传递规律，自建了摇摆振动单管吸收试验台；分别对静止和摇摆状态下TFE/NMP垂直管内降膜吸收进行实验研究。
实验结果表明，当其他初始参数一定时，在渔船常见的摇摆振动条件下，降膜吸收器的热、质传递优于静态下的情形；摇摆振动频率和幅度直接影响降膜吸收性能，适当减小摇摆周期或摇摆幅度均有利于提高降膜吸收性能。实验结果与理论计算较好吻合。研究表明TFE/NMP吸收是制冷系统完全能够满足渔船制冷要求。
Ocean fish culture of our country is faced with two serious problems, one is environment pollution and the other is energy waste. It is one of important ways to solve the problems to use absorption system on the ocean fishing. But the change of the performance of the absorber, which is an important component in the absorption machine, under the fluctuant state of the fisher is the key that determines whether the absorption system can be used on ocean fishers. In this paper the flow field of falling film along the inner of vertical tube is simulated and it's the necessary base of the further research that includes characteristics of heat and mass transfer in the absorber under the fluctuant state.
In this paper the ocean fisher's movement in the ocean is studied and the physical and the mathematical models of fisher are founded, then the expressions of the force by the movement are obtained. The expressions are combined with partial different equations of falling film under the static state, thus the mathematical model of the falling film under fluctuant state can be gained. After simplifying the equations and supposing the profile of velocity, the integral equation of the falling film is gotten. Then the flow field of the falling film can be simulated through dispersing the integral equation and using numerical methods.
An experimental apparatus of falling film absorption in a vacillating is set up to check the reliability of theoretical model and to have a deep understanding of heat and transfer of practical falling film absorption; Falling film absorption with TFE/NMP solution in a static vertical tube and that in a vacillating tube are investigated respectively.
The experiment results show that when other initial parameters are kept constant, the heat and mass transfer of falling film absorption under the condition of normal vacillation of fishing vessels is better than that in static status; The amplitude and period of vacillation directly influence the performance of the absorber and an adequate decrease of vacillation period or vacillation amplitude is beneficial to the absorption performance. This conclusion tallies with the numerical results. The TFE/NMP absorption refrigeration system can completely meet the demands of the refrigeration of fishing boats when the sea wind is not strong.
本文首先研究了船舶在海洋中的运动，建立了船舶摇摆运动的简化物理模型和数学模型，得到了运动附加力的表达式；并在此基础上将吸收管的运动附加力表达式代入静止状态下液膜流动的数学模型中，即得到了摇摆状态下液膜流动的数学模型；然后对液膜流动的数学模型进行了简化，在假定了速度分布的条件下，得出了液膜流动的积分方程，经过以上简化就将求解三维问题转化成为求解二维问题；将积分方程离散后用数值计算的方法模拟了整个流场。
为验证理论模型的可靠性并进一步深入了解实际摇摆降膜吸收过程中热、质传递规律，自建了摇摆振动单管吸收试验台；分别对静止和摇摆状态下TFE/NMP垂直管内降膜吸收进行实验研究。
实验结果表明，当其他初始参数一定时，在渔船常见的摇摆振动条件下，降膜吸收器的热、质传递优于静态下的情形；摇摆振动频率和幅度直接影响降膜吸收性能，适当减小摇摆周期或摇摆幅度均有利于提高降膜吸收性能。实验结果与理论计算较好吻合。研究表明TFE/NMP吸收是制冷系统完全能够满足渔船制冷要求。
Ocean fish culture of our country is faced with two serious problems, one is environment pollution and the other is energy waste. It is one of important ways to solve the problems to use absorption system on the ocean fishing. But the change of the performance of the absorber, which is an important component in the absorption machine, under the fluctuant state of the fisher is the key that determines whether the absorption system can be used on ocean fishers. In this paper the flow field of falling film along the inner of vertical tube is simulated and it's the necessary base of the further research that includes characteristics of heat and mass transfer in the absorber under the fluctuant state.
In this paper the ocean fisher's movement in the ocean is studied and the physical and the mathematical models of fisher are founded, then the expressions of the force by the movement are obtained. The expressions are combined with partial different equations of falling film under the static state, thus the mathematical model of the falling film under fluctuant state can be gained. After simplifying the equations and supposing the profile of velocity, the integral equation of the falling film is gotten. Then the flow field of the falling film can be simulated through dispersing the integral equation and using numerical methods.
An experimental apparatus of falling film absorption in a vacillating is set up to check the reliability of theoretical model and to have a deep understanding of heat and transfer of practical falling film absorption; Falling film absorption with TFE/NMP solution in a static vertical tube and that in a vacillating tube are investigated respectively.
The experiment results show that when other initial parameters are kept constant, the heat and mass transfer of falling film absorption under the condition of normal vacillation of fishing vessels is better than that in static status; The amplitude and period of vacillation directly influence the performance of the absorber and an adequate decrease of vacillation period or vacillation amplitude is beneficial to the absorption performance. This conclusion tallies with the numerical results. The TFE/NMP absorption refrigeration system can completely meet the demands of the refrigeration of fishing boats when the sea wind is not strong.
引文
[1] 制冷与空调手册．国防工业出版社，1984：1239．
[2] 章立标、张诗针．吸附式船用制冷系统．制冷，1995，No．1：79—81．
[3] 王如竹．固体吸附是制冷新技术．制冷技术，1999，No．2：4—7．
[4] Zhu Ruiqi: Experimental investigation on an adsorption system for producing chilled water. International Journal of Refrigeration, 1992, Vol. 15, No.1: 31—34.
[5] Truck exhaust gas-operated absorption refrigeration system, ASHRAE Journal, 1978, Vol. 20, No. 6.
[6] Automobile air conditioning using a rotary absorption/recompression system, Applied Energy, 1994, No. 49.
[7] 徐士鸣、袁一．利用渔船柴油机排烟余热制冷保鲜的可行性分析。渔业机械机器，1995，No．5：31—34．
[8] 郭庆堂、吴进发．实用制冷工程手册．中国建筑工业出版社，1994．
[9] 曹得胜．重视氨制冷剂在制冷空调上的应用．制冷学报，1996，No．2：54—56．
[10] Horuz. A comparison between ammonia-water and water-lithium bromide solutions in vapor absorption refrigeration system. International Communication of Heat Mass Transfer, 1998, Vo. 25: 711—721.
[11] U. Nowaczyk and F. Steimle. Thermophysical properties of new working fluid systems for absorption processes. International Journal of Refrigeration, 1992, Vol. 15, No.1: 10—15.
[12] 真下克之、石井盛郎、岛田忠男．太阳热吸收冷冻机．1989，No．64．
[13] 徐士鸣．吸收式制冷循环及制冷工质研究进展(Ⅱ)—新型吸收式制冷工质系．流体机械，1999，Vol．27，No．3：52—57．
[14] 王寒栋、胡连方．氨/硫氰化钠扩散吸收制冷系统实验研究．制冷，1999，No．3．
[15] 陈曙辉、陈光明、郑飞．吸收式制冷工质的发展．制冷学报，1998，No．2：45—52．
[16] 吴业正、韩宝琦．制冷原理及设备．西安交通大学出版社，1997(第二版)．
[17] 枷场、植村．冷冻，1968：784．
[18] L. F. Albright. AHSRAE Journal, 1965: 90.
[19] 杨思文．氨水吸收式制冷剂的基础理论和设计之十二．流体工程，1990，No：9．58—64．
[20]周兴禧、尉迟斌．水平原管上溴华锂溶液膜式吸收过程的传热和传质分析，流体工程，1986，No．6：14—52．
[21]李维、杨小琼等：水平原管外溴化锂水溶液将膜吸收过程数值分析，流体工程，1993，No．12：50—55．
[22]李大庆、陆震、尉迟斌：吸收器二维热质交换模型研究，流体机械，1995，No．6．
[23]樊永辉．吸收式制冷系统降膜吸收器二原设计方法，流体工程，1991，No．3．
[24]孙毅刚、陆震等．热质耦合过程二元计算模型，上海制冷协会年会论文集，1996．
[25]毛雯萍、陆震等．垂直管外溴化锂溶液降膜吸收的传热传质模型研究，流体机械，1996．No，9：47—51．
[26]王建平、朱天复等：溴化锂水溶液在小雷诺下降膜吸收的传热和传质，中国工程热物理年会1984年传热传质学术会议集，1984．
[27]Moon-Hyun Chun and Kyun-Tae Kim: Assessment of the new existing correlations for laminar and turbulent film condensation on a vertical surface, Int. Comm. Heat Mass Transfer, Vol. 7:431—441.
[28]G. Grossman: Simultaneous heat and mass transfer in film absorption under laminar flow, Int. J. Heat Mass Transfer, 1983, Vol. 26. No. 3:357-371.
[29]Neima Brauner, David Moalem Maron and Hanuch Meyerson: Coupled heat condensation and mass absorption with comparable concentratian of absorbent, Int. J. Heat Mass Transfer, 1989, Vol. 32, No. 10:1897-1906.
[30]Neima Brauner: Non-isothermal vapor absorption into falling film, Int. J. Heat Mass Transfer, 1991, Vol. 34, No. 3:767-784.
[31]Y.L. Tsay, T.F. Lin and W.M. Yan. Cooling of a falling liquid film through interficial heat and mass transfer, Int. J. Multiphase Flow, 1990, Vol. 16, No. 5: 853-865.
[32]I. Pop. Gravity: Driven laminar film along a vertical wall with surface mass transfer, Int. Comm. Heat Mass transfer, 1996, Vol. 23, No. 5:687-695.
[33]G.A. Ibrahim and G.A. Vinnicombe:A hybrid method to analyse the performance of falling film absorbers. Int. J. Heat Mass,Transfer, 1993, Vol. 36, No. 5:1383-1390.
[34]Neima Brauner and David Moalem Maron: Characteristics of inclined thin films, waviness and the associated mass transfer, Int. J. Heat Mass Transfer, 1982, Vol. 25, No. 1:99-110.
[35]H. Sabir, K.O. Suen and G.A. Vinnicombe: Investigation of effects of wave motion on the performance of a falling film absorber, Int. J. Heat Mass Transfer, 1996. Vol. 39, No. 12:2463-2472.
[36]K.J. Kim and N.S. Berman: Absorption of water vapor into falling films of aqueous lithium bromide, Int. J. Refrig. Vol. 18, No. 7:486-494.
[37]Y.S. Won and A.F. Millsl: Correlation of the effects of viscosity and surface tension on gas absorption rates into freely falling turbulent liquid films, Int. J. Heat Mass Transfer, 1982, Vol. 25, No:2.223-229.
[38]Gershon Grossman: Simultaneous heat and mass transfer in absorption of gases in turbulent liquid films, Int. J. Heat Mass Transfer, 1984, Vol. 27, No. 12:2635-2376.
[39]A.K. Bin: Mass transfer into a turbulent liquid film, Int. J. Heat Mass Transfer, 1983, Vol. 26, No. 7:981-991.
[40]L.P. Kholpanov and E. YA. Kenig: Coupled mass and heat transfer in a multi component turbulent falling liquid film, Int. J. Heat Mass Transfer, 1993, Vol. 36, No. 14:3647-3657.
[41]Liu YanLi、Xu Shiming、Zhang Lisong. Investigation of heat and mass transfer of falling film absorption inside a vertical tube with TFE/NMP as working fluid. International Conference on Energy conversion and Application. 2001. pp:378-384.
[42]C．O．本尼特、J．E．迈尔斯 著．动量、热量和质量传递．化学工业出版社．第三版．1988：251-257．
[43]刘艳丽，徐士鸣，张利嵩．垂直管内 TFE/NMP降膜吸收热质传递数值模拟．流体机械，2002，Vol．30：No．1．
[44]刘艳丽，徐士鸣，张利嵩．垂直管内 TFE/NMP降膜吸收过程中热质传递实验研究．低温工程，2002(1)：11-19．
[2] 章立标、张诗针．吸附式船用制冷系统．制冷，1995，No．1：79—81．
[3] 王如竹．固体吸附是制冷新技术．制冷技术，1999，No．2：4—7．
[4] Zhu Ruiqi: Experimental investigation on an adsorption system for producing chilled water. International Journal of Refrigeration, 1992, Vol. 15, No.1: 31—34.
[5] Truck exhaust gas-operated absorption refrigeration system, ASHRAE Journal, 1978, Vol. 20, No. 6.
[6] Automobile air conditioning using a rotary absorption/recompression system, Applied Energy, 1994, No. 49.
[7] 徐士鸣、袁一．利用渔船柴油机排烟余热制冷保鲜的可行性分析。渔业机械机器，1995，No．5：31—34．
[8] 郭庆堂、吴进发．实用制冷工程手册．中国建筑工业出版社，1994．
[9] 曹得胜．重视氨制冷剂在制冷空调上的应用．制冷学报，1996，No．2：54—56．
[10] Horuz. A comparison between ammonia-water and water-lithium bromide solutions in vapor absorption refrigeration system. International Communication of Heat Mass Transfer, 1998, Vo. 25: 711—721.
[11] U. Nowaczyk and F. Steimle. Thermophysical properties of new working fluid systems for absorption processes. International Journal of Refrigeration, 1992, Vol. 15, No.1: 10—15.
[12] 真下克之、石井盛郎、岛田忠男．太阳热吸收冷冻机．1989，No．64．
[13] 徐士鸣．吸收式制冷循环及制冷工质研究进展(Ⅱ)—新型吸收式制冷工质系．流体机械，1999，Vol．27，No．3：52—57．
[14] 王寒栋、胡连方．氨/硫氰化钠扩散吸收制冷系统实验研究．制冷，1999，No．3．
[15] 陈曙辉、陈光明、郑飞．吸收式制冷工质的发展．制冷学报，1998，No．2：45—52．
[16] 吴业正、韩宝琦．制冷原理及设备．西安交通大学出版社，1997(第二版)．
[17] 枷场、植村．冷冻，1968：784．
[18] L. F. Albright. AHSRAE Journal, 1965: 90.
[19] 杨思文．氨水吸收式制冷剂的基础理论和设计之十二．流体工程，1990，No：9．58—64．
[20]周兴禧、尉迟斌．水平原管上溴华锂溶液膜式吸收过程的传热和传质分析，流体工程，1986，No．6：14—52．
[21]李维、杨小琼等：水平原管外溴化锂水溶液将膜吸收过程数值分析，流体工程，1993，No．12：50—55．
[22]李大庆、陆震、尉迟斌：吸收器二维热质交换模型研究，流体机械，1995，No．6．
[23]樊永辉．吸收式制冷系统降膜吸收器二原设计方法，流体工程，1991，No．3．
[24]孙毅刚、陆震等．热质耦合过程二元计算模型，上海制冷协会年会论文集，1996．
[25]毛雯萍、陆震等．垂直管外溴化锂溶液降膜吸收的传热传质模型研究，流体机械，1996．No，9：47—51．
[26]王建平、朱天复等：溴化锂水溶液在小雷诺下降膜吸收的传热和传质，中国工程热物理年会1984年传热传质学术会议集，1984．
[27]Moon-Hyun Chun and Kyun-Tae Kim: Assessment of the new existing correlations for laminar and turbulent film condensation on a vertical surface, Int. Comm. Heat Mass Transfer, Vol. 7:431—441.
[28]G. Grossman: Simultaneous heat and mass transfer in film absorption under laminar flow, Int. J. Heat Mass Transfer, 1983, Vol. 26. No. 3:357-371.
[29]Neima Brauner, David Moalem Maron and Hanuch Meyerson: Coupled heat condensation and mass absorption with comparable concentratian of absorbent, Int. J. Heat Mass Transfer, 1989, Vol. 32, No. 10:1897-1906.
[30]Neima Brauner: Non-isothermal vapor absorption into falling film, Int. J. Heat Mass Transfer, 1991, Vol. 34, No. 3:767-784.
[31]Y.L. Tsay, T.F. Lin and W.M. Yan. Cooling of a falling liquid film through interficial heat and mass transfer, Int. J. Multiphase Flow, 1990, Vol. 16, No. 5: 853-865.
[32]I. Pop. Gravity: Driven laminar film along a vertical wall with surface mass transfer, Int. Comm. Heat Mass transfer, 1996, Vol. 23, No. 5:687-695.
[33]G.A. Ibrahim and G.A. Vinnicombe:A hybrid method to analyse the performance of falling film absorbers. Int. J. Heat Mass,Transfer, 1993, Vol. 36, No. 5:1383-1390.
[34]Neima Brauner and David Moalem Maron: Characteristics of inclined thin films, waviness and the associated mass transfer, Int. J. Heat Mass Transfer, 1982, Vol. 25, No. 1:99-110.
[35]H. Sabir, K.O. Suen and G.A. Vinnicombe: Investigation of effects of wave motion on the performance of a falling film absorber, Int. J. Heat Mass Transfer, 1996. Vol. 39, No. 12:2463-2472.
[36]K.J. Kim and N.S. Berman: Absorption of water vapor into falling films of aqueous lithium bromide, Int. J. Refrig. Vol. 18, No. 7:486-494.
[37]Y.S. Won and A.F. Millsl: Correlation of the effects of viscosity and surface tension on gas absorption rates into freely falling turbulent liquid films, Int. J. Heat Mass Transfer, 1982, Vol. 25, No:2.223-229.
[38]Gershon Grossman: Simultaneous heat and mass transfer in absorption of gases in turbulent liquid films, Int. J. Heat Mass Transfer, 1984, Vol. 27, No. 12:2635-2376.
[39]A.K. Bin: Mass transfer into a turbulent liquid film, Int. J. Heat Mass Transfer, 1983, Vol. 26, No. 7:981-991.
[40]L.P. Kholpanov and E. YA. Kenig: Coupled mass and heat transfer in a multi component turbulent falling liquid film, Int. J. Heat Mass Transfer, 1993, Vol. 36, No. 14:3647-3657.
[41]Liu YanLi、Xu Shiming、Zhang Lisong. Investigation of heat and mass transfer of falling film absorption inside a vertical tube with TFE/NMP as working fluid. International Conference on Energy conversion and Application. 2001. pp:378-384.
[42]C．O．本尼特、J．E．迈尔斯 著．动量、热量和质量传递．化学工业出版社．第三版．1988：251-257．
[43]刘艳丽，徐士鸣，张利嵩．垂直管内 TFE/NMP降膜吸收热质传递数值模拟．流体机械，2002，Vol．30：No．1．
[44]刘艳丽，徐士鸣，张利嵩．垂直管内 TFE/NMP降膜吸收过程中热质传递实验研究．低温工程，2002(1)：11-19．