复叠式热泵热水器相变蓄热系统研究
|
摘要
随着经济的发展和人民生活水平的提高,能源的过度开采和低利用效率,所造成的环境问题日益严重,成为制约经济发展和社会进步的不利因素。蓄能技术由于能够解决热能的供给与需求在时间和空间上的不匹配,而成为合理利用能源、减轻环境污染的有效途径。热泵热水器与传统的燃气、电热水器相比,节能效果明显,同时相变蓄热具有蓄热密度大、蓄放热温度恒定、容易控制等优点,热泵系统与蓄热水箱的有机结合已成为热水器研究的新热点。
本文将整个蓄热模箱完全浸入水箱中,并将其与蓄热水箱看作一个整体,通过理论模拟与实验分析,研究了复叠式蓄热型热泵热水器相变蓄热系统及其相变蓄热材料的特性。主要工作有:复叠式热泵热水器高、低温级制冷剂选择与各部件设计;适用于热泵系统的相变蓄热材料性能研究;复叠式热泵热水器相变蓄热系统理论模拟;相变蓄热系统蓄热、放热的性能测试实验台。
蓄热材料性能实验结果表明,十水碳酸钠与羧甲基纤维素对改善三水醋酸钠的过冷与相分离最为有效,十水碳酸钠最佳比例应在3%~5%,目前最适合与本课题的相变蓄热材料为石蜡-膨胀石墨相变蓄热材料。
对相变蓄热系统的理论模拟可知,蓄热模箱孔径有一个最佳尺寸值。蓄、放热过程中,蓄热水箱内部水温与蓄热材料温度存在明显的温度分层作用,蓄热过程中,水箱内的水有明显的自然对流现象。
对蓄热系统实验研究可知,蓄热过程中,水箱内水温最高位置为水箱中部(冷凝盘管顶部),放热过程中,蓄热材料可以起到稳定出水温度,减缓出水温度下降速度的作用。本相变蓄热系统在蓄热完成后,一次性提供的热水量,完全可以满足家庭用户的要求。同时,实验值与理论模拟值对比结果吻合良好,两者结果吻合良好,误差在可接受的范围内。
With the development of economy and elevation of People’s living level, the over-exploitation of energy, the use in low efficiency, which have resulted in environment pollutions serious day by day, have became adverse factors of restricting economic development and social progress. The technology of thermal storage, which was able to solve the unbalance of energy supply and demand in time and space, has become an effective way in rational use of energy and reducing pollution. Concerning with the traditional gas, electric water heaters,Heat pump water heater have more energy-saving effect. Thermal storage with phase change has become a new hot in energy using because of its advantages such as high energy storage density, charging with a constant temperature, easier to control and so on.
By theoretical simulation and experimental analysis, this paper study the phase change thermal storage system and its characteristics of phase-change material(PCM) of a cascade heat pump water heater with PCM, when immersing the PCM heat-exchanger into the container and taking the two as a whole. This research includes the tasks below: selecting the refrigerates of high and low temperature cycles and designing the components for cascade heat pump water heater; study the properties of the applicable PCM; theoretical simulation of the phase-change thermal storage system for the cascade heat pump water heater; thermal storing and exothermic parameters experimental apparatus of the thermal storage system.
PCM’s performance experimental results show that Na_2CO_3·10H_2O and are the best and thickener, of carboxymethocel nucleating agent optimal proportionNa_2CO_3·10H_2O is 3%-5%. Paraffin/expanded graphite is the best PCM for this heat pump water heater.
The theoretical simulation results show that there exists optimum aperture in the PCM heat-exchanger. In the heat storing and exothermic processes, there is distinct temperature stratification between the water and PCM in the water tank, while it has obvious phenomenon of natural convection in the heat storage process.
The experimental study results indicate that the highest water temperature lies on the central of the water tank (top of the condensing coils) in the thermal storage process; in the exothermic process, the thermal storage material has a function of stabilizing and slowing the decreasing rate of temperature of the outlet water. The hot water supplied by the thermal storage process can completely satisfy the requirements of the common family users. Moreover, it is also found that the experimental and theoretical results anastomosed well, with an acceptable error range.
本文将整个蓄热模箱完全浸入水箱中,并将其与蓄热水箱看作一个整体,通过理论模拟与实验分析,研究了复叠式蓄热型热泵热水器相变蓄热系统及其相变蓄热材料的特性。主要工作有:复叠式热泵热水器高、低温级制冷剂选择与各部件设计;适用于热泵系统的相变蓄热材料性能研究;复叠式热泵热水器相变蓄热系统理论模拟;相变蓄热系统蓄热、放热的性能测试实验台。
蓄热材料性能实验结果表明,十水碳酸钠与羧甲基纤维素对改善三水醋酸钠的过冷与相分离最为有效,十水碳酸钠最佳比例应在3%~5%,目前最适合与本课题的相变蓄热材料为石蜡-膨胀石墨相变蓄热材料。
对相变蓄热系统的理论模拟可知,蓄热模箱孔径有一个最佳尺寸值。蓄、放热过程中,蓄热水箱内部水温与蓄热材料温度存在明显的温度分层作用,蓄热过程中,水箱内的水有明显的自然对流现象。
对蓄热系统实验研究可知,蓄热过程中,水箱内水温最高位置为水箱中部(冷凝盘管顶部),放热过程中,蓄热材料可以起到稳定出水温度,减缓出水温度下降速度的作用。本相变蓄热系统在蓄热完成后,一次性提供的热水量,完全可以满足家庭用户的要求。同时,实验值与理论模拟值对比结果吻合良好,两者结果吻合良好,误差在可接受的范围内。
With the development of economy and elevation of People’s living level, the over-exploitation of energy, the use in low efficiency, which have resulted in environment pollutions serious day by day, have became adverse factors of restricting economic development and social progress. The technology of thermal storage, which was able to solve the unbalance of energy supply and demand in time and space, has become an effective way in rational use of energy and reducing pollution. Concerning with the traditional gas, electric water heaters,Heat pump water heater have more energy-saving effect. Thermal storage with phase change has become a new hot in energy using because of its advantages such as high energy storage density, charging with a constant temperature, easier to control and so on.
By theoretical simulation and experimental analysis, this paper study the phase change thermal storage system and its characteristics of phase-change material(PCM) of a cascade heat pump water heater with PCM, when immersing the PCM heat-exchanger into the container and taking the two as a whole. This research includes the tasks below: selecting the refrigerates of high and low temperature cycles and designing the components for cascade heat pump water heater; study the properties of the applicable PCM; theoretical simulation of the phase-change thermal storage system for the cascade heat pump water heater; thermal storing and exothermic parameters experimental apparatus of the thermal storage system.
PCM’s performance experimental results show that Na_2CO_3·10H_2O and are the best and thickener, of carboxymethocel nucleating agent optimal proportionNa_2CO_3·10H_2O is 3%-5%. Paraffin/expanded graphite is the best PCM for this heat pump water heater.
The theoretical simulation results show that there exists optimum aperture in the PCM heat-exchanger. In the heat storing and exothermic processes, there is distinct temperature stratification between the water and PCM in the water tank, while it has obvious phenomenon of natural convection in the heat storage process.
The experimental study results indicate that the highest water temperature lies on the central of the water tank (top of the condensing coils) in the thermal storage process; in the exothermic process, the thermal storage material has a function of stabilizing and slowing the decreasing rate of temperature of the outlet water. The hot water supplied by the thermal storage process can completely satisfy the requirements of the common family users. Moreover, it is also found that the experimental and theoretical results anastomosed well, with an acceptable error range.
引文
[1]姜勇,丁安勇,黎国康.相变储能材料的研究进展[J].广州化学.1999,(3):48-54
[2]王剑锋.相变储能材料的应用展望[J].河北化工,2005, (3):10-11
[3]龙惟定,王长庆,丁文婷.试论中国的能源结构与空调冷热源的选择取向[J].暖通空调.2000,30(5):27-32
[4]郑祖义.热泵空调系统的设计与创新[M].武汉:华中理工大学出版社.1994:13-16
[5]北京市2003居民能源统计[R].北京市节约能源办公室
[6]香港能源效率研究室能源统计报告[R].1998
[7]陈俊.相变蓄热技术的数值模拟研究[D].郑州:郑州大学.2007
[8] Laue J.Regional report Europe: "heat pumps-status and trends"[J].International Journal of Refrigeration,2002,25:414-420
[9] Vince C M,Ronald E,et al . Experimental Study of an R-407C Heat Pump Heater[J].ASHRAE Traps,2001.A
[10] Rousseau P G. Greyvenstein G. P.Enhancing the impact of heat pump water Heaters in the South African commercial sector[J].Energy,2000,25:51-57
[11] Bivens D B,et al . HCFC-22alternative for air conditioners and heat pumps[J].ASHRAE Transactions,1994,100(2):566-572
[12] Meyer J P,Greyvenstein G. P.Hot water for homes in South Africa with heat pump[J].Energy,1991,16(7):1039-1044
[13] Smith F J,Meiyer J P.Investigation of the potential effect of zero tropic refrigerant mixture on performance of a hot water heat pump[J].ASH RAE Transactions,1998,104(1): 387-394
[14] Spatz M W,Zheng J . R-22 Alternative refrigerant : Performance in unitary equipment[J].A SHRAE Transactions I993,99(2):779-785
[15] Neksa P,et al.CO2-heat pump water heater,characteristics,system design and experimental results[J].Int. J. Refrig,1998,21(3):172-179
[16] Neksa P.CO2 heat pump systems[J].Int. J.Refrig,2002,25:421-427
[17] Neksa P,et al.Commercial heat pumps for water heating and heat recovery.In:CO2 technology in refrigeration,heat pumps and air conditioningsystems[J].Mainz,Germany, 1999
[18] Saikawa M,Hashimoto K,Hasegawa H,et al.A basic study on CO2 heat pumps especially for hot water tap water supply.In:CO2 technology in refrigeration,heat pumps and air conditioning systems[J].Trondheim,Norway,1997
[19]管海清,马一太,杨俊兰.日本家用二氧化碳热泵热水器研究开发现状分析[J].家电科技,2004, (6):59-62
[20]刘岩,巫江虹.国内家用热泵热水器的研究现状和展望[J].节能与环保,2007,10:24-25
[21] S.M.Hasnain.Review on sustainable thermal energy storage technologies,part1:Heat storage materials and techniques.Energy Conveys Mgmt[J],1998,39:1127-1138
[22] Yousef H.Zurigat,Pedro R.Li che,Af shi n J.Ghajar.Influence of Inlet Geometry on Mixing in Thermal cline Thermal Energy Storage.Heat Mass Transfer,Pergamon Press plc[J],1991,34(1):115-125
[23] Royon L,Guiffant G,Flaud P.Investigation of heat transfer in a polymeric phase change material for low level heat storage[J] . Energy Conversion and Management,1997, 38(6):517-524
[24] R.Velraj,R.V.Seeniraj,B. Hafner et al.Heat transfer enhancement in a latent heat storage system[J].Solar Energy,1999,65(3):171-180
[25] L.F.Cabeza a,H.Mehling.Heat transfer enhancement in water when used as PCM in thermal energy storage.Applied Thermal Engineering[J].2002,22:1141-1151
[26] Osamu Miyatake, Muhammad Enamul, Kabir, Hidehiko Noda, Kouji Sugihara.Transient Characteristics and Performance of Hybrid Latent Heat Storage and Spray Flash Evaporation System . J. of Chemical Engineering of Japan[J],1997,30(6):1076-1082
[27] Yasushi Koito,Kotaro Tagawa,Yasuhiro Maruta,Kazuyoshi Tanaka,Osamu Miyatake.Effect of Pellet Size on Discharge Characteristics of Latent Heat Storage Columns Packed with Cross-Linked Polymer Pellets[J].J.of Chemical Engineering of Japan,2001, 34(6):819-827
[28]邢玉明,许听等.高温相变单元管蓄热过程数值模拟[J].航空动力报,2002,17(2):231-235
[29]姜益强,齐琦,姚杨,马最良.圆柱形壳管式相变蓄热单元的蓄热特性研究[J].太阳能学报,2008,29(1):29-34
[30]陈颖,邓先和,李筱萍,丁小江.圆柱形相变蓄热器放热性能的工业实验研究[J].广东工业大学学报.2002,19(2):41-45
[31]康艳兵,张寅平,朱颖秋,江亿.相变蓄热同心套管传热模型和性能分析[J].太阳能学报,1999,20(1):20-25
[32]龙建佑,朱冬生.三重同心套管相变传热的数值模拟与实验研究[J].中山大学学报.2007,46:303-305
[33] Jian-You Long,Dong-Sheng Zhu.Numerical and experimental study on heat pump water heater with PCM for thermal storage[J].Energy and Building,2008,40:666-672
[34]刘永忠,冯霄.复叠热泵冷冻干燥系统制冷剂的选择[J].华北电力大学学报,2003,9:105-108
[35]徐雪情.我国R22逐步禁用和替代物的现状与进展[J].制冷技术,2004,4:12-15
[36]曹德胜,史琳.制冷剂使用手册[M].北京:冶金工业出版社,2003
[37]刘玲,叶红卫.国内外蓄热材料发展概况[J].兰化科技,1998,9
[38]戴或,唐黎明.相变储热材料研究进展[J].化学世界,12,2001:662-665
[39]贺岩峰,张令轩等.热能储存材料研究进展[J].现代化工,1994, (8):8-10
[40]程玉蓉.用于建筑节能的相变蓄热材料热性能研究[D].杭州:浙江大学,2006
[41]徐建霞.中温太阳能集热系统相变材料的贮能性能及过冷特性的研究[D].广州:广东工业大学,2008
[42]张寅平,胡汉平,孔祥东等.相变贮能——理论和应用[M].合肥:中国科学技术大学出版社,1996
[43]王华,王胜林,饶文涛.高性能复合相变蓄热材料的制备与蓄热燃烧技术[M].北京:冶金工业出版社,2006
[44]方银贵.蓄能空调技术[M].北京:化学工业出版社,2005
[45]郭茶秀,魏新利.热能存储技术与应用[M].北京:化学工业出版社,2005
[46]樊栓狮,梁德青,杨向阳等.储能材料与技术[M].北京:化学工业出版社,2004
[47]崔海亭,杨峰.蓄热技术及其应用[M].北京:化学工业出版社,2004
[48]张正国,王学泽,方晓明.石蜡-膨胀石墨复合相变材料的结构与热性能[J].华南理工大学学报,2006(3):1-5
[49]张正国,邵刚,方晓明.石蜡-膨胀石墨复合相变储热材料的研究[J].太阳能学报,2005(5):698-702
[50]熊辉东.太阳能相变蓄热槽的数值模拟研究[D].郑州:郑州大学,2006
[51]罗智特,杜雁霞,贾代勇.相变材料蓄冷球蓄冷过程的数值模拟[J].制冷空调与电力机械,2004, (25)
[52]李晓燕.蓄冷球内高温相变材料蓄冷特性的研究[J].节能技术,2004,22(3)9-V 11.
[53] Vince C.Mei,Fang C. Chen,Ronald E.Domitrovic.A study of a natural convection immersed condenser heat pump water heater[J].ASHRAE Transactions,v 109 PART 2 ,2003:3-8
[54]郭宽良,孔祥谦,陈善年编.计算传热学[M].北京:中国科学技术出版社,1988
[55]王福军.计算流体东西学分析—CFD软件原理与应用[M].北京:清华大学出版社,2004
[56]韩占忠,王敬,兰小平.FLUENT流体工程仿真计算实例与应用[M].北京:北京理工大学出版社,2004
[57]周光炯.流体力学[M].北京:高等教育出版社,2000
[58]王昊.采用新型相变材料蓄热槽蓄放热特性数值计算方法探讨[D].北京:北京工业大学,2003
[59]孔祥谦.有限单元法在传热学中的应用[M].北京:科学出版社,1998
[2]王剑锋.相变储能材料的应用展望[J].河北化工,2005, (3):10-11
[3]龙惟定,王长庆,丁文婷.试论中国的能源结构与空调冷热源的选择取向[J].暖通空调.2000,30(5):27-32
[4]郑祖义.热泵空调系统的设计与创新[M].武汉:华中理工大学出版社.1994:13-16
[5]北京市2003居民能源统计[R].北京市节约能源办公室
[6]香港能源效率研究室能源统计报告[R].1998
[7]陈俊.相变蓄热技术的数值模拟研究[D].郑州:郑州大学.2007
[8] Laue J.Regional report Europe: "heat pumps-status and trends"[J].International Journal of Refrigeration,2002,25:414-420
[9] Vince C M,Ronald E,et al . Experimental Study of an R-407C Heat Pump Heater[J].ASHRAE Traps,2001.A
[10] Rousseau P G. Greyvenstein G. P.Enhancing the impact of heat pump water Heaters in the South African commercial sector[J].Energy,2000,25:51-57
[11] Bivens D B,et al . HCFC-22alternative for air conditioners and heat pumps[J].ASHRAE Transactions,1994,100(2):566-572
[12] Meyer J P,Greyvenstein G. P.Hot water for homes in South Africa with heat pump[J].Energy,1991,16(7):1039-1044
[13] Smith F J,Meiyer J P.Investigation of the potential effect of zero tropic refrigerant mixture on performance of a hot water heat pump[J].ASH RAE Transactions,1998,104(1): 387-394
[14] Spatz M W,Zheng J . R-22 Alternative refrigerant : Performance in unitary equipment[J].A SHRAE Transactions I993,99(2):779-785
[15] Neksa P,et al.CO2-heat pump water heater,characteristics,system design and experimental results[J].Int. J. Refrig,1998,21(3):172-179
[16] Neksa P.CO2 heat pump systems[J].Int. J.Refrig,2002,25:421-427
[17] Neksa P,et al.Commercial heat pumps for water heating and heat recovery.In:CO2 technology in refrigeration,heat pumps and air conditioningsystems[J].Mainz,Germany, 1999
[18] Saikawa M,Hashimoto K,Hasegawa H,et al.A basic study on CO2 heat pumps especially for hot water tap water supply.In:CO2 technology in refrigeration,heat pumps and air conditioning systems[J].Trondheim,Norway,1997
[19]管海清,马一太,杨俊兰.日本家用二氧化碳热泵热水器研究开发现状分析[J].家电科技,2004, (6):59-62
[20]刘岩,巫江虹.国内家用热泵热水器的研究现状和展望[J].节能与环保,2007,10:24-25
[21] S.M.Hasnain.Review on sustainable thermal energy storage technologies,part1:Heat storage materials and techniques.Energy Conveys Mgmt[J],1998,39:1127-1138
[22] Yousef H.Zurigat,Pedro R.Li che,Af shi n J.Ghajar.Influence of Inlet Geometry on Mixing in Thermal cline Thermal Energy Storage.Heat Mass Transfer,Pergamon Press plc[J],1991,34(1):115-125
[23] Royon L,Guiffant G,Flaud P.Investigation of heat transfer in a polymeric phase change material for low level heat storage[J] . Energy Conversion and Management,1997, 38(6):517-524
[24] R.Velraj,R.V.Seeniraj,B. Hafner et al.Heat transfer enhancement in a latent heat storage system[J].Solar Energy,1999,65(3):171-180
[25] L.F.Cabeza a,H.Mehling.Heat transfer enhancement in water when used as PCM in thermal energy storage.Applied Thermal Engineering[J].2002,22:1141-1151
[26] Osamu Miyatake, Muhammad Enamul, Kabir, Hidehiko Noda, Kouji Sugihara.Transient Characteristics and Performance of Hybrid Latent Heat Storage and Spray Flash Evaporation System . J. of Chemical Engineering of Japan[J],1997,30(6):1076-1082
[27] Yasushi Koito,Kotaro Tagawa,Yasuhiro Maruta,Kazuyoshi Tanaka,Osamu Miyatake.Effect of Pellet Size on Discharge Characteristics of Latent Heat Storage Columns Packed with Cross-Linked Polymer Pellets[J].J.of Chemical Engineering of Japan,2001, 34(6):819-827
[28]邢玉明,许听等.高温相变单元管蓄热过程数值模拟[J].航空动力报,2002,17(2):231-235
[29]姜益强,齐琦,姚杨,马最良.圆柱形壳管式相变蓄热单元的蓄热特性研究[J].太阳能学报,2008,29(1):29-34
[30]陈颖,邓先和,李筱萍,丁小江.圆柱形相变蓄热器放热性能的工业实验研究[J].广东工业大学学报.2002,19(2):41-45
[31]康艳兵,张寅平,朱颖秋,江亿.相变蓄热同心套管传热模型和性能分析[J].太阳能学报,1999,20(1):20-25
[32]龙建佑,朱冬生.三重同心套管相变传热的数值模拟与实验研究[J].中山大学学报.2007,46:303-305
[33] Jian-You Long,Dong-Sheng Zhu.Numerical and experimental study on heat pump water heater with PCM for thermal storage[J].Energy and Building,2008,40:666-672
[34]刘永忠,冯霄.复叠热泵冷冻干燥系统制冷剂的选择[J].华北电力大学学报,2003,9:105-108
[35]徐雪情.我国R22逐步禁用和替代物的现状与进展[J].制冷技术,2004,4:12-15
[36]曹德胜,史琳.制冷剂使用手册[M].北京:冶金工业出版社,2003
[37]刘玲,叶红卫.国内外蓄热材料发展概况[J].兰化科技,1998,9
[38]戴或,唐黎明.相变储热材料研究进展[J].化学世界,12,2001:662-665
[39]贺岩峰,张令轩等.热能储存材料研究进展[J].现代化工,1994, (8):8-10
[40]程玉蓉.用于建筑节能的相变蓄热材料热性能研究[D].杭州:浙江大学,2006
[41]徐建霞.中温太阳能集热系统相变材料的贮能性能及过冷特性的研究[D].广州:广东工业大学,2008
[42]张寅平,胡汉平,孔祥东等.相变贮能——理论和应用[M].合肥:中国科学技术大学出版社,1996
[43]王华,王胜林,饶文涛.高性能复合相变蓄热材料的制备与蓄热燃烧技术[M].北京:冶金工业出版社,2006
[44]方银贵.蓄能空调技术[M].北京:化学工业出版社,2005
[45]郭茶秀,魏新利.热能存储技术与应用[M].北京:化学工业出版社,2005
[46]樊栓狮,梁德青,杨向阳等.储能材料与技术[M].北京:化学工业出版社,2004
[47]崔海亭,杨峰.蓄热技术及其应用[M].北京:化学工业出版社,2004
[48]张正国,王学泽,方晓明.石蜡-膨胀石墨复合相变材料的结构与热性能[J].华南理工大学学报,2006(3):1-5
[49]张正国,邵刚,方晓明.石蜡-膨胀石墨复合相变储热材料的研究[J].太阳能学报,2005(5):698-702
[50]熊辉东.太阳能相变蓄热槽的数值模拟研究[D].郑州:郑州大学,2006
[51]罗智特,杜雁霞,贾代勇.相变材料蓄冷球蓄冷过程的数值模拟[J].制冷空调与电力机械,2004, (25)
[52]李晓燕.蓄冷球内高温相变材料蓄冷特性的研究[J].节能技术,2004,22(3)9-V 11.
[53] Vince C.Mei,Fang C. Chen,Ronald E.Domitrovic.A study of a natural convection immersed condenser heat pump water heater[J].ASHRAE Transactions,v 109 PART 2 ,2003:3-8
[54]郭宽良,孔祥谦,陈善年编.计算传热学[M].北京:中国科学技术出版社,1988
[55]王福军.计算流体东西学分析—CFD软件原理与应用[M].北京:清华大学出版社,2004
[56]韩占忠,王敬,兰小平.FLUENT流体工程仿真计算实例与应用[M].北京:北京理工大学出版社,2004
[57]周光炯.流体力学[M].北京:高等教育出版社,2000
[58]王昊.采用新型相变材料蓄热槽蓄放热特性数值计算方法探讨[D].北京:北京工业大学,2003
[59]孔祥谦.有限单元法在传热学中的应用[M].北京:科学出版社,1998