开式热源塔的数值模拟
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摘要
能源节约与资源综合利用是我国经济和社会发展的一项长远战略方针。对于空调系统来讲,寻求廉价的低品位可再生冷热源是节能降耗的关键措施。因此,寻求节能环保的冷热源方案是个十分重要的课题。
热源塔是一种较新型的热质交换设备,它利用工作介质与空气进行热质交换,适时地按需采集空气冷源或热源,可为热泵机组提供低品位可再生冷热源,充分利用了可再生能源,做到了节能降耗。
由于热源塔问世及应用时间不长,其结构及运行参数尚在不断改进之中,目前还没有形成主导产品;同时,对热源塔内部热质交换过程的理论研究也基本处于空白阶段。因此,对热源塔进行理论上的研究具有重要的理论意义和实用价值。
本文主要工作内容及结论如下:
1、对热源塔的三种典型结构、工作原理及应用性能进行了详细阐述,比较发现改进型闭式结构具有较完善的工作性能,但结构也最复杂,造价相对较高。开式结构虽然造价低,但性能相对最差。普通型闭式结构性能则居中。但无论哪种结构,冬季工况均需注意溶液浓度下降的问题;
2、对开式热源塔内部热质交换过程进行了理论分析,在焓湿图上直观地描述了冬夏季工况下塔内空气和溶液各自的状态变化过程,并提出了可用来进一步了解传热传质在开式热源塔内的进行程度的热交换效率公式;
3、对影响开式热源塔设备性能的因素进行了分析,并提出了几条完善开式热源塔设备性能的措施;
4、分别应用FLUENT和MATLAB软件对开式热源塔内部热质交换过程进行了数值模拟,得到了开式热源塔在夏季和冬季工况下各参数分布图,并进行了相关的分析。
本文对开式热源塔内部的热质交换过程进行了较深入的理论研究,希望能为热源塔的设计研发及工程应用提供理论指导,也希望能为热源塔的进一步研究提供参考。
Energy-saving and comprehensive utilization of resources is a long-term strategic policy of our country's economic and social development. Concerned the air-conditioning system, to seek low-cost low-grade renewable cold and heat source is a key measure of energy-saving. Therefore, the search for saving and environmental cold and heat source is a very important issue.
Heat-source tower is a relatively new type heat and mass transfer equipment, which could collect cold or heat source from air on demand, via the heat and mass exchange of working fluids and air, providing low-grade renewable cold and heat source for heat pumps. This equipment makes full use of renewable sources, achieving energy-saving.
Due to the short-time in practice, heat-source tower still needs to be improved or optimized in respect to its structure and operating parameters, and the leading product has not yet formed. Also there is hardly theoretical research of the heat and mass transfer process in the tower. Therefore, the theoretical research of heat-source tower possesses important theoretical significance and practical value.
In this paper, work and conclusions are as follows:
1. Three typical heat-source towers with different structures are compared in aspects of working principle, application characteristics and performance, etc. It is found that the improved closed type has better performance in the operation, yet it has the most complex structure and relatively high cost. Although the open type has low cost, it has the relatively worst performance, while the common closed type is between the two above-mentioned. But each structure should notice the problem of the decline of working fluids concentration in winter.
2. Theoretical analysis of the heat and mass transfer process in open-type heat-source tower is carried out in this paper, and the change process of air and solution state in the tower is visually described on h-d chart, respectively in winter and summer. And the heat exchange efficiency formula is put forward to further understand the degree of heat and mass transfer in tower.
3. The impact factors of open-type heat-source tower's performance are analyzed and several improved measures of its performance are put forward in this paper.
4. Application of FLUENT and MATLAB respectively, numerical simulation of the heat and mass transfer process in open-type heat-source tower is carried out. Distribution charts of various parameters in summer and winter is obtained, also the relevant analysis is carried out followed.
More in-depth theoretical research of the heat and mass transfer process in open-type heat-source tower is carried out in this paper, hoping to provide theoretical guidance in the equipment's R & D and engineering application, and also hope to provide reference for its further research.
热源塔是一种较新型的热质交换设备,它利用工作介质与空气进行热质交换,适时地按需采集空气冷源或热源,可为热泵机组提供低品位可再生冷热源,充分利用了可再生能源,做到了节能降耗。
由于热源塔问世及应用时间不长,其结构及运行参数尚在不断改进之中,目前还没有形成主导产品;同时,对热源塔内部热质交换过程的理论研究也基本处于空白阶段。因此,对热源塔进行理论上的研究具有重要的理论意义和实用价值。
本文主要工作内容及结论如下:
1、对热源塔的三种典型结构、工作原理及应用性能进行了详细阐述,比较发现改进型闭式结构具有较完善的工作性能,但结构也最复杂,造价相对较高。开式结构虽然造价低,但性能相对最差。普通型闭式结构性能则居中。但无论哪种结构,冬季工况均需注意溶液浓度下降的问题;
2、对开式热源塔内部热质交换过程进行了理论分析,在焓湿图上直观地描述了冬夏季工况下塔内空气和溶液各自的状态变化过程,并提出了可用来进一步了解传热传质在开式热源塔内的进行程度的热交换效率公式;
3、对影响开式热源塔设备性能的因素进行了分析,并提出了几条完善开式热源塔设备性能的措施;
4、分别应用FLUENT和MATLAB软件对开式热源塔内部热质交换过程进行了数值模拟,得到了开式热源塔在夏季和冬季工况下各参数分布图,并进行了相关的分析。
本文对开式热源塔内部的热质交换过程进行了较深入的理论研究,希望能为热源塔的设计研发及工程应用提供理论指导,也希望能为热源塔的进一步研究提供参考。
Energy-saving and comprehensive utilization of resources is a long-term strategic policy of our country's economic and social development. Concerned the air-conditioning system, to seek low-cost low-grade renewable cold and heat source is a key measure of energy-saving. Therefore, the search for saving and environmental cold and heat source is a very important issue.
Heat-source tower is a relatively new type heat and mass transfer equipment, which could collect cold or heat source from air on demand, via the heat and mass exchange of working fluids and air, providing low-grade renewable cold and heat source for heat pumps. This equipment makes full use of renewable sources, achieving energy-saving.
Due to the short-time in practice, heat-source tower still needs to be improved or optimized in respect to its structure and operating parameters, and the leading product has not yet formed. Also there is hardly theoretical research of the heat and mass transfer process in the tower. Therefore, the theoretical research of heat-source tower possesses important theoretical significance and practical value.
In this paper, work and conclusions are as follows:
1. Three typical heat-source towers with different structures are compared in aspects of working principle, application characteristics and performance, etc. It is found that the improved closed type has better performance in the operation, yet it has the most complex structure and relatively high cost. Although the open type has low cost, it has the relatively worst performance, while the common closed type is between the two above-mentioned. But each structure should notice the problem of the decline of working fluids concentration in winter.
2. Theoretical analysis of the heat and mass transfer process in open-type heat-source tower is carried out in this paper, and the change process of air and solution state in the tower is visually described on h-d chart, respectively in winter and summer. And the heat exchange efficiency formula is put forward to further understand the degree of heat and mass transfer in tower.
3. The impact factors of open-type heat-source tower's performance are analyzed and several improved measures of its performance are put forward in this paper.
4. Application of FLUENT and MATLAB respectively, numerical simulation of the heat and mass transfer process in open-type heat-source tower is carried out. Distribution charts of various parameters in summer and winter is obtained, also the relevant analysis is carried out followed.
More in-depth theoretical research of the heat and mass transfer process in open-type heat-source tower is carried out in this paper, hoping to provide theoretical guidance in the equipment's R & D and engineering application, and also hope to provide reference for its further research.
引文
[1]高军,王丽,耿永军.浅论中央空调系统节能[J].科技信息(学术版),2008.21:321-323.
[2]龙恩深主编.冷热源工程[M].重庆大学出版社.2002.10.
[3]范存养.大空间建筑空调设计及工程实录[M].中国建筑工业出版社,2001,386-388;443-445.
[4]朱颖心,王刚,江亿.区域供冷系统能耗分析[J].暖通空调,2008,38(1):36-40.
[5]方国明.热源塔热泵在空调工程中的应用实践[J].制冷空调工程技术,2008.3:13-16.
[6]王志林,刘秋克,李静,热源塔[P].中华人民共和国国家知识产权局,ZL 200620073647.8,2007.8.8.
[7]刘秋克,闭式热源塔[P].中华人民共和国国家知识产权局,ZL 200810031368.9.2008.10.8.
[8]刘秋克,一种热源塔热泵[P].中华人民共和国国家知识产权局,ZL 200810031355.1,2008.9.24.
[9]刘秋克,方国明.桐庐大酒店热泵空调冷(热)源方案浅析[J].中国能源学会.
[10]张晨,杨洪海,刘秋克等.闭式热源塔用作空调冷热源的分析[J].建筑热能通风空调,2009,28(6):71-73.
[11]吴喜平.蓄冷技术和蓄热电锅炉在空调中的应用[M].同济大学出版社,2000.95-100.
[12]刘秋克,王武英,方国明.热源塔热泵技术在南方的应用[J].地源热泵,2008.6:33-38.
[13]刘秋克,王武英.热源塔热泵低热能再生技术在我国南方的应用[J].建设科技,2008,15:124-125.
[14]热源塔热泵发明者的戏剧人生.地源热泵,2008,7:62-65.
[15]连之伟主编.热质交换原理与设备[M].中国建筑工业出版社.2001.9.
[16]N.P.彻雷密西诺夫,P.N.彻雷密西诺夫著.凉水塔[M].石油工业出版社,1984.
[17]赵荣义,等.空气调节[M].北京:中国建筑工业出版社,2006.
[18]廉乐明等编著.工程热力学[M].中国建筑工业出版社.2000.
[19]王明华.Licl_H2O液体吸收式除湿系统的研究[D].北京:北京化工大学化工学院,2005.
[20]王倩,宋垚臻.空气与水直接接触热质交换国内外研究进展[J].茂名学院学报.2007.12,29-33.
[2l]王瑞金,张凯,王刚编著.Fluent技术基础与应用实例[M].北京:清华大学出版社,2007.2.
[22]赵玉新.Fluent中文全教程.
[23]S.A.Morsi and A.J.Alexander.An investigation of particle trajectories in two-phase flow systems[J].Journal of Fluid Mechanics,1972(55):193-208.
[24]W.E.Ranz and W.R.Marshall,Jr.Evaporation from Drops,Part Ⅰ.Chem. Eng.Prog.,1952.3,48(3):141-146.
[25]W.E.Ranz and W.R.Marshall,Jr.Evaporation from Drops,Part Ⅱ.Chem.Eng.Prog.,1952.4,48(4):173-180.
[26]王未儿.机械通风式横流冷却塔的数值模拟[D].山东大学硕士学位论文,2006.
[27]龙天渝等编著.计算流体力学[M].重庆:重庆大学出版社,2007.3.
[28]Stevens D I,Braun J E and Klein S A.An effectiveness model of liquid-desiccant system heat/mass exchangers[J].Solar Energy,1989,42(6):449-455.
[29]X.Y.Chen,Z.Li,Y.Jiang,K.Y.Qu.Analytical solution of adiabatic heat and mass transfer process in packed-type liquid desiccant equipment and its application[J].Solar Energy,2006,80:1509-1516.
[30]Factor H M and Grossman G.A packed bed dehumidifier/regenerator for solar air conditioning with liquid desiccants[J].Solar Energy,1980,24:541-550.
[31]路则峰,陈沛霖,张旭.逆流填料式液体除湿系统传热传质过程解析解[J].同济大学学报,2000,28(3):342-347.
[32]Oberg V,Goswami D Y.Experimental study of heat and mass transfer in a packed bed liquid desiccant air dehumidifier[J].Transactions of the ASME Journal of Solar Energy Engineering,1998,120(3):289-297.
[33]Sadasivam M,Balakrishnan A R.Effectiveness-NTU method for design of a packed-bed liquid desiccant dehumidifiers[J].Transactions of the Institution of Chemical Engineers,1992,70(2):572-577.
[34]Khan A Y,Ball H D.Development of a generalized model for performance evaluation of packed-type liquid sorbent dehumidifiers and regenerators [C]//ASHRAE Trans,1992,98(1):525-533.
[35]周兴禧编.制冷空调工程中的质量传递[M].上海:上海交通大学出版社,1991.
[36]路则峰.吸湿剂溶液-空气系统热湿交换过程的研究[D].同济大学博士学位论文,1999.
[37]易晓勤,刘晓华,江亿.常用除湿溶液的性质分析[J].HTML版.
[38]Takeshl Sako,Toshlkatsu Hakuta and Hlroshl Yoshltome.Vapor Pressures of Binary(H20-HCI,-MgCI2,and -CaC12) and Ternary(H20-MgC12-CaC12)Aqueous Solutions.J.Chem.Eng.Data 1985,30,224-228.
[39]Jin-Soo Kim and Huen Lee.Vapor Pressures of Water + Lithium Chloride +Ethylene Glycol and Water + Lithium Chloride+ Lithium Bromide +Ethylene Glycol.J.Chem.Eng.Data 1995,40,496-498.
[40]G.O.G.Lof,et al.Coefficients of heat and mass transfer in a packed bed suitable for solar regeneration of aqueous lithium chloride solutions.Journal of Solar Energy Engineering,1984,106(9).
[2]龙恩深主编.冷热源工程[M].重庆大学出版社.2002.10.
[3]范存养.大空间建筑空调设计及工程实录[M].中国建筑工业出版社,2001,386-388;443-445.
[4]朱颖心,王刚,江亿.区域供冷系统能耗分析[J].暖通空调,2008,38(1):36-40.
[5]方国明.热源塔热泵在空调工程中的应用实践[J].制冷空调工程技术,2008.3:13-16.
[6]王志林,刘秋克,李静,热源塔[P].中华人民共和国国家知识产权局,ZL 200620073647.8,2007.8.8.
[7]刘秋克,闭式热源塔[P].中华人民共和国国家知识产权局,ZL 200810031368.9.2008.10.8.
[8]刘秋克,一种热源塔热泵[P].中华人民共和国国家知识产权局,ZL 200810031355.1,2008.9.24.
[9]刘秋克,方国明.桐庐大酒店热泵空调冷(热)源方案浅析[J].中国能源学会.
[10]张晨,杨洪海,刘秋克等.闭式热源塔用作空调冷热源的分析[J].建筑热能通风空调,2009,28(6):71-73.
[11]吴喜平.蓄冷技术和蓄热电锅炉在空调中的应用[M].同济大学出版社,2000.95-100.
[12]刘秋克,王武英,方国明.热源塔热泵技术在南方的应用[J].地源热泵,2008.6:33-38.
[13]刘秋克,王武英.热源塔热泵低热能再生技术在我国南方的应用[J].建设科技,2008,15:124-125.
[14]热源塔热泵发明者的戏剧人生.地源热泵,2008,7:62-65.
[15]连之伟主编.热质交换原理与设备[M].中国建筑工业出版社.2001.9.
[16]N.P.彻雷密西诺夫,P.N.彻雷密西诺夫著.凉水塔[M].石油工业出版社,1984.
[17]赵荣义,等.空气调节[M].北京:中国建筑工业出版社,2006.
[18]廉乐明等编著.工程热力学[M].中国建筑工业出版社.2000.
[19]王明华.Licl_H2O液体吸收式除湿系统的研究[D].北京:北京化工大学化工学院,2005.
[20]王倩,宋垚臻.空气与水直接接触热质交换国内外研究进展[J].茂名学院学报.2007.12,29-33.
[2l]王瑞金,张凯,王刚编著.Fluent技术基础与应用实例[M].北京:清华大学出版社,2007.2.
[22]赵玉新.Fluent中文全教程.
[23]S.A.Morsi and A.J.Alexander.An investigation of particle trajectories in two-phase flow systems[J].Journal of Fluid Mechanics,1972(55):193-208.
[24]W.E.Ranz and W.R.Marshall,Jr.Evaporation from Drops,Part Ⅰ.Chem. Eng.Prog.,1952.3,48(3):141-146.
[25]W.E.Ranz and W.R.Marshall,Jr.Evaporation from Drops,Part Ⅱ.Chem.Eng.Prog.,1952.4,48(4):173-180.
[26]王未儿.机械通风式横流冷却塔的数值模拟[D].山东大学硕士学位论文,2006.
[27]龙天渝等编著.计算流体力学[M].重庆:重庆大学出版社,2007.3.
[28]Stevens D I,Braun J E and Klein S A.An effectiveness model of liquid-desiccant system heat/mass exchangers[J].Solar Energy,1989,42(6):449-455.
[29]X.Y.Chen,Z.Li,Y.Jiang,K.Y.Qu.Analytical solution of adiabatic heat and mass transfer process in packed-type liquid desiccant equipment and its application[J].Solar Energy,2006,80:1509-1516.
[30]Factor H M and Grossman G.A packed bed dehumidifier/regenerator for solar air conditioning with liquid desiccants[J].Solar Energy,1980,24:541-550.
[31]路则峰,陈沛霖,张旭.逆流填料式液体除湿系统传热传质过程解析解[J].同济大学学报,2000,28(3):342-347.
[32]Oberg V,Goswami D Y.Experimental study of heat and mass transfer in a packed bed liquid desiccant air dehumidifier[J].Transactions of the ASME Journal of Solar Energy Engineering,1998,120(3):289-297.
[33]Sadasivam M,Balakrishnan A R.Effectiveness-NTU method for design of a packed-bed liquid desiccant dehumidifiers[J].Transactions of the Institution of Chemical Engineers,1992,70(2):572-577.
[34]Khan A Y,Ball H D.Development of a generalized model for performance evaluation of packed-type liquid sorbent dehumidifiers and regenerators [C]//ASHRAE Trans,1992,98(1):525-533.
[35]周兴禧编.制冷空调工程中的质量传递[M].上海:上海交通大学出版社,1991.
[36]路则峰.吸湿剂溶液-空气系统热湿交换过程的研究[D].同济大学博士学位论文,1999.
[37]易晓勤,刘晓华,江亿.常用除湿溶液的性质分析[J].HTML版.
[38]Takeshl Sako,Toshlkatsu Hakuta and Hlroshl Yoshltome.Vapor Pressures of Binary(H20-HCI,-MgCI2,and -CaC12) and Ternary(H20-MgC12-CaC12)Aqueous Solutions.J.Chem.Eng.Data 1985,30,224-228.
[39]Jin-Soo Kim and Huen Lee.Vapor Pressures of Water + Lithium Chloride +Ethylene Glycol and Water + Lithium Chloride+ Lithium Bromide +Ethylene Glycol.J.Chem.Eng.Data 1995,40,496-498.
[40]G.O.G.Lof,et al.Coefficients of heat and mass transfer in a packed bed suitable for solar regeneration of aqueous lithium chloride solutions.Journal of Solar Energy Engineering,1984,106(9).