竖直U型埋管换热性能研究及其工程应用
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摘要
能源和环境问题是当今世界各国面临的重大问题,特别是随着北京申办2008年奥运会的成功,清洁能源地利用问题更成为我们面临的重要课题。地源热泵作为一项高效节能、绿色环保型的空调技术,在国外已成为一种广泛采用的供热空调方式,而在国内正处于研究和应用推广阶段,有着巨大的发展潜力。垂直深埋U型管式地源热泵以其占地面积少、可用范围广、灵活性较高、恒温效果好、换热效率高、维护费用低等众多优势,日益流行。
文中首先研究了土壤温度分布特性,并针对广州地区地下60米以内土壤温度分布进行了模拟计算,分析了土壤温度的变化规律。然后建立了垂直U型埋管式土壤源热泵地下换热埋管周围土壤温度场的三维稳态传热模型,模拟了冬季工况下埋管出口水温及周围土壤温度场的分布情况。再由数值模拟和工程实地测试的方法,进一步确定不同水流量、不同岩土导热系数对地下换热器出水温度的影响程度,分析不同的回填材料、运行方式及不同的埋管间距对地下换热器传热性能的影响,为土壤源热泵系统长期高效运行提供了理论参考。
此外,本文还通过对土壤源热泵系统的动态冷热负荷的变化,对地埋管设计尺寸的影响进行了进一步的计算和分析。课题选用DeST软件对广州某实际工程进行了全年动态负荷计算,在全年逐月总冷热负荷及逐月冷热负荷峰值计算结果的基础上选用ASHRAE推荐使用的地源热泵设计模拟软件GLHEPRO 3.0来进行30年运行模拟,分别对地下换热器尺寸的主要影响因素进行了系统性的综合分析,以期为地源热泵在我国的推广应用提供建议和参考。
Energy source and environment become the important problems in every country all over the world with succeeding in applying the 2008 Olympic Games, and the utilization of clean energy becomes the important task for us especially. Ground-source heat pump systems have been widely applied to both residential and commercial heating and cooling in America and Europe as these systems can make significant contributions to reductions in electrical energy usage and have been recognized as an environmental-friendly alternative to conventional unitary system. However, this technology has seldom been adopted so far in our country. Many a work of research on GSHP and popularizing application need to be done. Vertical U-Tube ground-coupled heat pumps have become increasingly popular because of any outstanding advantage it has, such as: fewer area requirement, fewer limits, running steadily, better performance, lower costs on system maintenance etc.
The characteristics of soil temperature distribution are studied at the beginning of the paper, and the computational model of original soil temperature field distribution is established for Guangzhou district. The temperature within 60m underground is simulated and the results are accorded with experimental data. Then, a three-dimensional model of the steady heat transfer around a single vertical U-tube for GSHP is established and the exit water temperature and the soil temperature distribution around the buried pipe running in winter are simulated, and the results are tallied with experimental data. In addition, the influencing factors based on the numerical method can be applied widely to confirm the extent of the buried-pipe outlet water temperature influenced by different circulate water storm and depth of well and different thermal conductivity of soil and rock around the buried-pipe and to analyze the influence of underground heat-exchanger’s heat transfer by different back-filled materials and different operation ways and different distances between the buried-pipes. It can offer reference of GSHP system running high effectively in a long time.
Besides, the influence of the different dynamic heating and cooling load were calculated and simulated for the GCHP system. Comparing all the actual data, the simulation work were preceded by means of the relative software to prove the feasibility of the system. First, DeST is used to calculate the annual dynamic load. On the basis of monthly total cooling and heating loads and monthly peak cooling and heating loads, the main impact factors of vertical U-tube heat exchanger size and performance are simulated and analyzed through GLHEPRO3.0, recommended by ASHRAE as a good designing and simulating software for GCHPS, to carry on the task of simulation for 30 years. The purpose of doing this is to give some concrete suggestion and reference for the promotion of GCHPS in our country.
文中首先研究了土壤温度分布特性,并针对广州地区地下60米以内土壤温度分布进行了模拟计算,分析了土壤温度的变化规律。然后建立了垂直U型埋管式土壤源热泵地下换热埋管周围土壤温度场的三维稳态传热模型,模拟了冬季工况下埋管出口水温及周围土壤温度场的分布情况。再由数值模拟和工程实地测试的方法,进一步确定不同水流量、不同岩土导热系数对地下换热器出水温度的影响程度,分析不同的回填材料、运行方式及不同的埋管间距对地下换热器传热性能的影响,为土壤源热泵系统长期高效运行提供了理论参考。
此外,本文还通过对土壤源热泵系统的动态冷热负荷的变化,对地埋管设计尺寸的影响进行了进一步的计算和分析。课题选用DeST软件对广州某实际工程进行了全年动态负荷计算,在全年逐月总冷热负荷及逐月冷热负荷峰值计算结果的基础上选用ASHRAE推荐使用的地源热泵设计模拟软件GLHEPRO 3.0来进行30年运行模拟,分别对地下换热器尺寸的主要影响因素进行了系统性的综合分析,以期为地源热泵在我国的推广应用提供建议和参考。
Energy source and environment become the important problems in every country all over the world with succeeding in applying the 2008 Olympic Games, and the utilization of clean energy becomes the important task for us especially. Ground-source heat pump systems have been widely applied to both residential and commercial heating and cooling in America and Europe as these systems can make significant contributions to reductions in electrical energy usage and have been recognized as an environmental-friendly alternative to conventional unitary system. However, this technology has seldom been adopted so far in our country. Many a work of research on GSHP and popularizing application need to be done. Vertical U-Tube ground-coupled heat pumps have become increasingly popular because of any outstanding advantage it has, such as: fewer area requirement, fewer limits, running steadily, better performance, lower costs on system maintenance etc.
The characteristics of soil temperature distribution are studied at the beginning of the paper, and the computational model of original soil temperature field distribution is established for Guangzhou district. The temperature within 60m underground is simulated and the results are accorded with experimental data. Then, a three-dimensional model of the steady heat transfer around a single vertical U-tube for GSHP is established and the exit water temperature and the soil temperature distribution around the buried pipe running in winter are simulated, and the results are tallied with experimental data. In addition, the influencing factors based on the numerical method can be applied widely to confirm the extent of the buried-pipe outlet water temperature influenced by different circulate water storm and depth of well and different thermal conductivity of soil and rock around the buried-pipe and to analyze the influence of underground heat-exchanger’s heat transfer by different back-filled materials and different operation ways and different distances between the buried-pipes. It can offer reference of GSHP system running high effectively in a long time.
Besides, the influence of the different dynamic heating and cooling load were calculated and simulated for the GCHP system. Comparing all the actual data, the simulation work were preceded by means of the relative software to prove the feasibility of the system. First, DeST is used to calculate the annual dynamic load. On the basis of monthly total cooling and heating loads and monthly peak cooling and heating loads, the main impact factors of vertical U-tube heat exchanger size and performance are simulated and analyzed through GLHEPRO3.0, recommended by ASHRAE as a good designing and simulating software for GCHPS, to carry on the task of simulation for 30 years. The purpose of doing this is to give some concrete suggestion and reference for the promotion of GCHPS in our country.
引文
[1]付祥钊.夏热冬冷地区建筑节能技术.北京:中国建筑工业出版社, 2002. 301~306
[2]徐邦欲,陆亚俊,马最良.热泵.北京:中国建筑出版社, 1988. 66～68
[3] Gary Phetteplace,William Sulliva. Performance of a hybrid ground-coupled heat pump system. ASHRAE Trans, 1998, 104(2): 763～774
[4] Stephen.P.Kavanaugh. A design method for hybrid ground-source heat pumps. ASHRAE Trans, 1998, 104(2): 691～698
[5]宋春玲,张国强,张泉.土壤源热泵——种节能的中央空调系统冷热源.节能, 1998, 12: 7-9
[6]曲云霞,张林华,崔永章.地源热泵及其应用分析.可再生能源, 2002(4): 7-9
[7] Merl Baker. Design and Performance of a Residential Earth Heat Pump. Trans ASHVE, 1953(59): 371-394
[8]刁乃仁,方肇洪,过增元.地源热泵空调系统的研究开发与应用.节能与环保, 2001(1):23-26
[9]殷平.地源热泵在中国.现代空调第3辑, 2001. 1-10
[10]吕悦,杨立平,周沫等.国内土壤源热泵应用情况调查报告.工程建设与设计, 2005(6): 5～10
[11] Shonder, J.A.,V.D.Baxter, P, J.Hughes, etc. A comparison of vertical ground heat exchanger design software for commercial applications. ASHRAE Trans, 2000, 106(1): 831～842
[12]徐伟.地源热泵工程技术指南.北京:中国建筑工业出版社, 2001
[13]高祖锟.用于供暖的土壤—水热泵系统.暖通空调, 1995(4): 9～12
[14]涂锋华,赵军.地源热泵的工程应用与环保节能特性分析.节能与环保,2001(3): 33-35
[15]章俞昌,潘金文.地源热泵技术的特点及其在空调工程中的应用.工程建设与设计, 2003(8):20-22
[16]曲云霞,张林华,方肇洪等.地源热泵地下环路的设计方法.流体机械,2002, 30(9): 50-52
[17] Steven Kavanaugh. Development of design tools for ground-source heat pump piping. ASHRAE Trans, 1998, 2(104): 932～937
[18] YavuzturkC., J.D.Spitler, S.J.Rees. A transient two-dimensional finite volume model for the simulation of vertical U-tube ground heat exchangers. ASHRAE Trans, 1999, 105(2): 465～474
[19] Sanner B. Ground coupled heat pumps with seasonal cold storage. Proceedings of the International Energy Agency Heat Pump Conference, Publ by Elsevier Science Publishers, 1993. 301
[20]柳晓雷,王德林,方雄洪.垂直埋管地源热泵的圆柱面传热模型及简化计算.山东建筑工程学院学报, 2001, 16(1): 47-51
[21]章熙民,任泽需编著.传热学.北京:中国建筑工业出版社, 1997
[22]曾和义,方肇洪. U型管地热换热器中介质轴向温度的数学模型.山东建筑工程学院学报, 2002, 17(1)
[23] Zeng H Y, Diao N. R and Fang Z. H, A finite line-source model for boreholes in geothermal heat exchangers. Heat Transfer-Asian Research, 2002, 31(7): 558-567
[24]张喜明,于立强.土壤源热泵垂直埋管周围温度场数理模型.节能技术, 2001, 19(4): 5-6
[25] Yavuzdurk C,and Spitler D. A transient two-dimensional finite volume model for the simulation of vertical U-tube ground heat exchangers. ASHRAE Transactions, 1999, 105(2)
[26]朱明善.工程热力学.清华大学出版社, 1995
[27]赵军,宋德坤,李新国.埋地换热器放热工况的现场运行实验研究.太阳能学报, 2005(4)
[28] S. P. Rottmayer, and W. A. Beckman. Simulation of a Single Vertical U-Tube Ground Heat Exchanger in an Infinite Medium. ASHRAE Transactions, 1997, 103(2): 651-659
[29] Cenk. Yavuzturk, Jeffrey D. Spitler, etal. A transient two-dimensional finite volume model for the simulation of vertical U-tube ground heat exchangers. ASHRAE Trans, 1999, 105(2): 465-472
[30] S.P. Kavanaugh. Ground source heat pumps. ASHRAE Journal, 1998, 40(10): 31-35
[31] Cenk Yavuzturk. Modeling of vertical ground loop heat exchangers for ground source heat pump systems. Ph.D. dissertation, Oklahoma State University, 1999
[32] Kavanaugh S P. Kevin Rafferty. Ground-source Heat Pumps: Design of Geothermal Systems for Commercial and Institutional Buildings. ASHRAE, Atlanta, Ca, 1997
[33] A. D. Chiasson, C. Yavuzturk, and W. J. Talbert. Design of School Building HVAC Retrofit with Hybrid Geothermal Heat-Pump System. Journal of Architectural Engineering, 2004, 10(3): 103-111
[34] David R. Dinse, Geothermal Systems for School, ASHRAE Journal, 1998
[35] Bose J E. Geothermal Heat Pumps Introductory Guide. Oklahoma State University Ground Source Heat Pump Publications, 1997
[36]杨世铭,陶文铨.传热学(第三版).北京:高等教育出版社, 1998
[37]兰州石油机械研究所编.换热器(上).北京:中国石化出版社, 1986
[38] Elliotl H.Spilker. Ground-coupled heat loop design using thermal conductivity testing and the effect of different backfill materials on vertical bore length. ASHRAE Trans, 1998, 104(2): 775～779
[39] Frank J. Zenarduzzi, Chris B.H.Crass. The importance of grouting to enhance the performance of earth systems. ASHRAE Trans, 2000, 107(1): 424～434
[40]崔萍,刁乃仁,方肇洪.地热换热器间歇运行工况分析.山东建筑工程学院学报, 2001, 16(1): 52-57
[41]高青,李明,乔广等.间歇过程地温恢复特性及其规律模拟计算分析.热科学与技术, 2004, 3(3)
[42]地源热泵系统工程技术规范(GB 50366-2005)
[43] Marita L. Allan, Steve P. Kavanaugh. Thermal conductivity of cementitious grouts and impact on heat exchanger length design for ground source heat pumps. HVAC and R Research, 1999, 5(2):87-98
[44] Charles P. Remund, James T. Lund. Thermal enhancement of bentonite grouts for vertical GSHP systems. American Society of Mechanical Engineers, Advanced Energy Systems Division (Publication) AES, v 29, Heat Pump and Refrigeration Systems Design, Analysis, and Applications, 1993. 95-106
[45]庄迎春,孙友宏,谢康和.直埋闭式地源热泵回填土性能研究.太阳能学报, 2004(4):216-220
[46] Zhang Q, Murphy WE. Measurement of Thermal Conductivity for three Borehole fill materials used for GSHP [A]. ASHARE Transaction, Symposia papers [C]. 1997, 106(2): 434-441
[47]刘宪英,王勇,胡鸣明等.地源热泵地下垂直埋管换热器的试验研究.重庆建筑大学学报, 1999, 21(5): 21-26
[48]李元旦,张旭,周亚素.土壤源热泵冬季工况下启动特性的实验研究.暖通空调, 2001, 31(1): 17~20
[49] J.A.Edwards. Heat Transfer from Earth-Coupled Heat Exchangers Ex1985, HI-85- 02: 70-80
[50]方肇洪.竖直U型埋管地源热泵空调系统的设计与安装.现代空调,2001(3):101-105
[51]刘宪英,胡鸣明,魏唐棣.地源热泵地下埋管换热器传热模型综述.重庆建筑大学学报, 1999, 21(4): 106~111
[52] D.A.Ball, R.D.Fischer, D.L.Hodgett. Design Methods for Ground-Source Heat Pumps. ASHRARE Transations, 1983, 89(Part2B): 416-440
[2]徐邦欲,陆亚俊,马最良.热泵.北京:中国建筑出版社, 1988. 66～68
[3] Gary Phetteplace,William Sulliva. Performance of a hybrid ground-coupled heat pump system. ASHRAE Trans, 1998, 104(2): 763～774
[4] Stephen.P.Kavanaugh. A design method for hybrid ground-source heat pumps. ASHRAE Trans, 1998, 104(2): 691～698
[5]宋春玲,张国强,张泉.土壤源热泵——种节能的中央空调系统冷热源.节能, 1998, 12: 7-9
[6]曲云霞,张林华,崔永章.地源热泵及其应用分析.可再生能源, 2002(4): 7-9
[7] Merl Baker. Design and Performance of a Residential Earth Heat Pump. Trans ASHVE, 1953(59): 371-394
[8]刁乃仁,方肇洪,过增元.地源热泵空调系统的研究开发与应用.节能与环保, 2001(1):23-26
[9]殷平.地源热泵在中国.现代空调第3辑, 2001. 1-10
[10]吕悦,杨立平,周沫等.国内土壤源热泵应用情况调查报告.工程建设与设计, 2005(6): 5～10
[11] Shonder, J.A.,V.D.Baxter, P, J.Hughes, etc. A comparison of vertical ground heat exchanger design software for commercial applications. ASHRAE Trans, 2000, 106(1): 831～842
[12]徐伟.地源热泵工程技术指南.北京:中国建筑工业出版社, 2001
[13]高祖锟.用于供暖的土壤—水热泵系统.暖通空调, 1995(4): 9～12
[14]涂锋华,赵军.地源热泵的工程应用与环保节能特性分析.节能与环保,2001(3): 33-35
[15]章俞昌,潘金文.地源热泵技术的特点及其在空调工程中的应用.工程建设与设计, 2003(8):20-22
[16]曲云霞,张林华,方肇洪等.地源热泵地下环路的设计方法.流体机械,2002, 30(9): 50-52
[17] Steven Kavanaugh. Development of design tools for ground-source heat pump piping. ASHRAE Trans, 1998, 2(104): 932～937
[18] YavuzturkC., J.D.Spitler, S.J.Rees. A transient two-dimensional finite volume model for the simulation of vertical U-tube ground heat exchangers. ASHRAE Trans, 1999, 105(2): 465～474
[19] Sanner B. Ground coupled heat pumps with seasonal cold storage. Proceedings of the International Energy Agency Heat Pump Conference, Publ by Elsevier Science Publishers, 1993. 301
[20]柳晓雷,王德林,方雄洪.垂直埋管地源热泵的圆柱面传热模型及简化计算.山东建筑工程学院学报, 2001, 16(1): 47-51
[21]章熙民,任泽需编著.传热学.北京:中国建筑工业出版社, 1997
[22]曾和义,方肇洪. U型管地热换热器中介质轴向温度的数学模型.山东建筑工程学院学报, 2002, 17(1)
[23] Zeng H Y, Diao N. R and Fang Z. H, A finite line-source model for boreholes in geothermal heat exchangers. Heat Transfer-Asian Research, 2002, 31(7): 558-567
[24]张喜明,于立强.土壤源热泵垂直埋管周围温度场数理模型.节能技术, 2001, 19(4): 5-6
[25] Yavuzdurk C,and Spitler D. A transient two-dimensional finite volume model for the simulation of vertical U-tube ground heat exchangers. ASHRAE Transactions, 1999, 105(2)
[26]朱明善.工程热力学.清华大学出版社, 1995
[27]赵军,宋德坤,李新国.埋地换热器放热工况的现场运行实验研究.太阳能学报, 2005(4)
[28] S. P. Rottmayer, and W. A. Beckman. Simulation of a Single Vertical U-Tube Ground Heat Exchanger in an Infinite Medium. ASHRAE Transactions, 1997, 103(2): 651-659
[29] Cenk. Yavuzturk, Jeffrey D. Spitler, etal. A transient two-dimensional finite volume model for the simulation of vertical U-tube ground heat exchangers. ASHRAE Trans, 1999, 105(2): 465-472
[30] S.P. Kavanaugh. Ground source heat pumps. ASHRAE Journal, 1998, 40(10): 31-35
[31] Cenk Yavuzturk. Modeling of vertical ground loop heat exchangers for ground source heat pump systems. Ph.D. dissertation, Oklahoma State University, 1999
[32] Kavanaugh S P. Kevin Rafferty. Ground-source Heat Pumps: Design of Geothermal Systems for Commercial and Institutional Buildings. ASHRAE, Atlanta, Ca, 1997
[33] A. D. Chiasson, C. Yavuzturk, and W. J. Talbert. Design of School Building HVAC Retrofit with Hybrid Geothermal Heat-Pump System. Journal of Architectural Engineering, 2004, 10(3): 103-111
[34] David R. Dinse, Geothermal Systems for School, ASHRAE Journal, 1998
[35] Bose J E. Geothermal Heat Pumps Introductory Guide. Oklahoma State University Ground Source Heat Pump Publications, 1997
[36]杨世铭,陶文铨.传热学(第三版).北京:高等教育出版社, 1998
[37]兰州石油机械研究所编.换热器(上).北京:中国石化出版社, 1986
[38] Elliotl H.Spilker. Ground-coupled heat loop design using thermal conductivity testing and the effect of different backfill materials on vertical bore length. ASHRAE Trans, 1998, 104(2): 775～779
[39] Frank J. Zenarduzzi, Chris B.H.Crass. The importance of grouting to enhance the performance of earth systems. ASHRAE Trans, 2000, 107(1): 424～434
[40]崔萍,刁乃仁,方肇洪.地热换热器间歇运行工况分析.山东建筑工程学院学报, 2001, 16(1): 52-57
[41]高青,李明,乔广等.间歇过程地温恢复特性及其规律模拟计算分析.热科学与技术, 2004, 3(3)
[42]地源热泵系统工程技术规范(GB 50366-2005)
[43] Marita L. Allan, Steve P. Kavanaugh. Thermal conductivity of cementitious grouts and impact on heat exchanger length design for ground source heat pumps. HVAC and R Research, 1999, 5(2):87-98
[44] Charles P. Remund, James T. Lund. Thermal enhancement of bentonite grouts for vertical GSHP systems. American Society of Mechanical Engineers, Advanced Energy Systems Division (Publication) AES, v 29, Heat Pump and Refrigeration Systems Design, Analysis, and Applications, 1993. 95-106
[45]庄迎春,孙友宏,谢康和.直埋闭式地源热泵回填土性能研究.太阳能学报, 2004(4):216-220
[46] Zhang Q, Murphy WE. Measurement of Thermal Conductivity for three Borehole fill materials used for GSHP [A]. ASHARE Transaction, Symposia papers [C]. 1997, 106(2): 434-441
[47]刘宪英,王勇,胡鸣明等.地源热泵地下垂直埋管换热器的试验研究.重庆建筑大学学报, 1999, 21(5): 21-26
[48]李元旦,张旭,周亚素.土壤源热泵冬季工况下启动特性的实验研究.暖通空调, 2001, 31(1): 17~20
[49] J.A.Edwards. Heat Transfer from Earth-Coupled Heat Exchangers Ex1985, HI-85- 02: 70-80
[50]方肇洪.竖直U型埋管地源热泵空调系统的设计与安装.现代空调,2001(3):101-105
[51]刘宪英,胡鸣明,魏唐棣.地源热泵地下埋管换热器传热模型综述.重庆建筑大学学报, 1999, 21(4): 106~111
[52] D.A.Ball, R.D.Fischer, D.L.Hodgett. Design Methods for Ground-Source Heat Pumps. ASHRARE Transations, 1983, 89(Part2B): 416-440