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西北日光温室传热学简化模型构建及温光高效新结构初探
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摘要
日光温室由于其结构上的特殊性,使其特别适宜于在我国广大的西北地区大面积推广应用,近年来也获得了极大的发展。西北各地出现了结构各异的不同类型的新型日光温室。但目前仍存在部分结构设计不合理,光能利用率低,保温性能差,缺乏系统理论研究成果等问题。但我们详细研究不难发现,尽管温室结构各异,但其基本结构也是有规律可循。因此,我们完全可以通过详细深入地研究,发现其潜在的内部规律。从而解决日光温室现在面临的建设混乱、缺乏统一理论指导的问题。
     本研究论文针对西北地区的典型日光温室类型,分别对构造不同的日光温室进行了室内外太阳辐射,室内外气温及各结构部件的温度分布,室内外表面温度、热流量,土壤温度,后期栽培管理等环境要素的连续观测。并利用观测的数据分析了供试日光温室的热工性能。该研究可以为温室建筑的结构优化、环境控制及室内作物的栽培提供非常必要的理论基础。本研究旨在通过系统地研究分析,建立适用于西北地区日光温室的结构设计和传热理论,进而为实践中的日光温室建造提供理论指导。同时根据典型结构日光温室的实测数据对典型日及典型天气下温室内部的整体热工性能和光照变化规律进行了分析。首先,详细地计算了日光温室各结构部分的传热损失类型及耗热规律,同时计算了主要构件的散热能耗率。其次,对日光温室各结构部分的散热进行了整体的对比分析,得到了主要的散热途径,以及可以进行结构改进的部分;并得到了日光温室经济后墙厚度的理论。再次,对日光温室的太阳辐射量进行了对比分析,并详细讨论了储热的规律和现有结构的不足,进而得到结构改进的方法。
     从严格意义的传热学分析角度来说,温室系统是一个非常非常复杂的三维周期性非稳态热传导、辐射、对流过程。但结合其结构的传热学规律,我们构建了西北地区日光温室简化传热学平衡模型:ΔQ=Qsun+Qprotect+Qlongwave+Qvent+Qsoil+Qground20。在研究过程中,我们只考虑日光温室这个整体单元对于外界的能量传递,进而可以清晰地掌握日光温室整体的热平衡和传热规律。通过系统的对各代表结构的详细分析计算,我们得到了西北地区日光温室的传热基本规律。在典型结构日光温室整体的热量损失中,白天的热损失约占到总热损的80%,夜间的损失仅为20%左右。在夜间,温室的热量损失中约有70%是通过维护结构的传热进行的。约有30%是因为冷风渗透而引起的。相比之下,这白天损失的能量中,约有65%的热损失是通过温室维护结构损失的,其中一部分为通过整体维护结构的传热损失约占35%,采光面的辐射损失约占到30%。在白天的热损失中,约有35%是通过通风而损失的。
     通过构建和应用日光温室传热学简化模型,分析得出日光温室所截获太阳能的水平较低。我们建立了动态可变采光角采光理论,并开发了新型的可变倾角采光日光温室新结构,并对其结构的性能进行了研究。通过研究,可变采光倾角温室较普通固定采光角温室能从整体上提高温室采光性能和温度指标。通过试验分析,可变采光倾角温室内的光照度较普通固定采光角温室有较大幅度的增加。在本试验条件下,可变采光倾角温室较普通固定采光倾角温室,整体采光性能平均提高25.6%。同时,可变采光倾角温室内的温度较普通固定采光角温室有较明显的增加,整体平均温度提高3.6℃。
     针对简化模型所揭示的因为日光温室后墙蓄热不足而导致其保温性差的问题,我们研发了相变保温后墙温室结构。通过研究,Na_2SO_4·10H_2O和Na2CO3·10H_2O体系,以试样质量比4∶6的组合较为理想,相变温度分为两个阶段,适合于满足一般温室生产对温度的要求。但是,长期使用过程中仍然存在过冷现象和相分离。Na_2SO_4·10H_2O和Na_2HPO_4·12H_2O体系以试样质量比1.9∶7.0的组合较为理想,相变温度稳定,过冷和相分离均能很好的满足要求。同时本实验条件下,相变墙温室内的温度波动幅度比普通温室小3.5℃;平均提高室内温度1.9℃,最大可提高5.8℃。
     通过本文的研究,实现了以下几个创新点。第一,在对日光温室热平衡详细研究的基础上,通过系统分析日光温室的传热特性,掌握了日光温室的传热规律。第二,建立并验证了西北地区日光温室传热学简化模型,该模型可以准确地分析日光温室的热工状况。同时该模型也揭示了日光温室的结构改进的方向和方法。第三,针对西北地区日光温室存在的采光性能低的问题,开发了可变倾角采光面日光温室新结构,并对该结构的温光性能进行了研究。研究表明,该结构对提高日光温室的太阳能利用率效果显著,整体采光性能平均提高25.6%。第四,针对日光温室现存的保温蓄热性能差的问题,研究了新型的相变保温新材料,并将其应用于西北日光温室。对该新结构日光温室热学性能研究表明,该结构可以大幅度提高日光温室的蓄热能力,有很强的应用价值。
Due to its particularity of structure, solar greenhouse is asuitable for protected horticulture facilities in an arid andsemi-arid region in northwest China. Solar greenhouse has alsogotten maximum development under the promotion of technicalinnovation in recent years. But,there are many problems in presentgreenhouse production which include less feasible structure,lowsolar radiation utilization rate, bad performance of heatpreservation and lack of theoretical research results.Based on thestudy of component and structure scheme, Different type of solargreenhouse has a specific similar structure and regularity. Andin addition, we can find the potential laws and to draw the rulesto value the uncertainty of the solar greenhouse system innorth-west of China. Then the suitable decision which can solvethe problem we faced in designing and operation management can bedrawn up out based on these foundations.
     The solar greenhouse environment factors which include solarradiation, air and surface temperature,temperature distributionand response behaviors of structure element, heat flux density ofstructure element, effect of soil temperature, and the cultivationmanagements in middle and late stages were measured continuouslyin four typical testing solar greenhouses in northwest region ofChina. And the solar greenhouse characteristics of thermalperformance were analyzed from the above measured data.The studyof characteristics of thermal performance may give the necessary theoretical basis for structure optimization,environment controland crop cultivation. In addition the solar greenhousecharacteristics of thermal performance and variation law of theillumination in the greenhouse were analyzed under the typical datesand the typical external climatic conditions according to themeasurement data.Firstly, detailed calculation method was appliedto the heat flux density of structure element and the thermalconsumption law. Secondly, based the comparative analysis of theheat flux density of different structure element, mainly heatdissipation way was be analyzed, and then the structure elementwhich should be improved can be found. The study of economicthickness of the greenhouse’ backwall has established a theoreticalanalyzing model on the basis of experimental study. Thirdly, thetransmission of solar radiation into the greenhouse can be acquiredaccording to the solar radiation inside and outside thegreenhouse.The law of thermal storage were analyzed and summarized.So we will found the way to overcome the drawbacks of the greenhousestructures.
     According to the concepts of classical heat transfer theory,the solar greenhouse thermal system is a very complicatedthree-dimensional、unsteady process of state thermal conduction,radiation and thermal convection. Based on the heat transfer lawof solar greenhouse, the simplified model of heat transfer in thesolar greenhouse was established and validated using fieldexperiment data (ΔQ=Qsun+Qprotect+Qlongwave+Qvent+Qsoil+Qground20). The solargreenhouse is considered as a complete unit in the simplified modelof heat transfer. Then we grasp heat transfer law of solar greenhouseclearly. Thermal loss rate of the typical structure solar greenhousein daytime is80%, and the thermal loss rate at night is20%. Therate of the heat which loss by maintenance structure is65%indaytime, and the same rate is70%at night. The rate of the heatwhich loss by ventilation is35%in daytime, and the same rate is30%at night.
     Based on this established simplified model, we found that thesolar interception rate is relatively low. This paper studies and analyzes the experimental data by experiment comparison andlighting analysis method. Then it puts forward a new structuralmodel of high-performance greenhouse what is called a“solar-greenhouse with variable incidence angle”. It’s technicalperformance including lighting and structure are discussed andcompared theoretically. Through the research the variable structure,the solar-greenhouse with variable incidence angle is moreefficient in utilization of solar energy and raising temperature.Illumination in the greenhouse with variable incidence angle hasa great enhancement comparing with normal type. The increasing rateof lighting performance is25.6%. The mean indoor temperatureincreased roughly by3.6℃.
     Simplified model revealed that solar greenhouse has the problemof lack of thermal storage. Then it will lead to poor thermalinsulation properties. We developed the PCM wall structuregreenhouse. By researching their thermal properties by DifferentialScanning Celemeter (DSC), for the new compound PCM composed ofNa_2SO_4·10H_2O and Na_2CO_3·10H_2O, the sample in t he mass proportionof4∶6is suitable for greenhouse. The phase transformationtemperature which divided into two stages meets the need of plantgrowth. During the application process, the phenomena of supercooling and phase segregation can’t be eliminated completely. Forthe new compound PCM composed of Na_2SO_4·10H_2O and Na2HPO4·12H_2O,the sample in the mass proportion of1.9∶7is suitable forgreenhouse. The phase transformation temperature remain stable,the phenomena of super cooling and phase segregation meet therequirements. Under the experimental conditions, The indoortemperature fluctuations of the PCM wall structure greenhouse is3.5℃lower than the temperature of the normal wall structure. Theindoor average temperature has increased by1.9degrees and canbe increased by5.8degrees.
     By researching thermal properties of the solar greenhouse, fourinnovative points well be realized. Firstly, based on the studyof characteristics of thermal performance, may give the necessarytheoretical basis for structure optimization,we grasp heat transfer law of solar greenhouse. Secondly, the simplified model of heattransfer in the solar greenhouse was established and validated usingfield experiment data. Accord to the simplified model of heattransfer in the solar greenhouse showed by the certain theory, Itmainly deals with theoretic investigation and practical study ofseveral typical solar greenhouse. Thirdly, in order to solve theproblem of the lower solar energy utilization ratio in thegreenhouse, we research and develop a new structural model ofhigh-performance greenhouse what is called a “solar-greenhouse withvariable incidence angle”. Through the research the variablestructure, the solar-greenhouse with variable incidence angle ismore efficient in utilization of solar energy and raisingtemperature. Illumination in the greenhouse with variable incidenceangle has a great enhancement comparing with normal type. Theincreasing rate of lighting performance is25.6%. Finally, in orderto solve the problem of the lower thermal storage performance inthe greenhouse, we developed the PCM wall structure greenhouse.Then the thermal storage performance of solar greenhouse wassignificantly increased. The theory is very practical in theexploration of the solar greenhouse structure and the managementof solar greenhouse.
引文
白义奎,佟国红,姜传军,袁芳.2002.预应力拉索拱结构在阳光温室骨架设计中的应用[J].钢结构,3(17):14~15.
    陈珊1,孙继银1,罗晓春2.2011.目标表面太阳辐射特性研究[J].红外技术,33(03):147~150
    陈翠英.2006.墙体的蓄放热特性对室内热环境调节作用的研究.[硕士学位论文].大连:大连理工大学.
    陈端生,郑海山,张建国,等.1992.日光温室气象环境综合研究(三):几种弧型采光屋面温室内直射光量的比较研究[J].农业工程学报,8(04):78~82.
    陈端生.1994.中国节能型日光温室建筑与环境研究进展[J].土壤,10(1):123~129.
    陈青云,汪政富.1996.节能型日光温室热环境的动态模拟[J].中国农业大学学报,1(1):67~72.
    陈正法,梁称福,黄小平.2000.四湖地区节能日光温室结构和原理[J],农业工程学报,16(01):75~78.
    戴彧,唐黎明.2001.相变储热材料研究进展[J].化学世界,(12):662~665.
    董瑞.2007.沙荒地日光温室墙体传热性能研究.[博士学位论文].济南:山东建筑大学热能工程学院.
    杜军,王怀彬,杨励丹.2000.温室内气温与土温相关性传热模型[J].哈尔滨工业大学学报,32(5):1~4.
    高峰,孙成权等.2000.我国太阳能开发利用的现状和建议[M].能源工程,(5):8~11.
    葛晓光.2005.我国蔬菜日光温室产业的现状与升级问题的探讨(一)—我国蔬菜日光温室发展与存在的问题[J].农村实用工程技术.温室园艺,(08):12~14.
    郭廷玮,刘鉴民,M·DAGUENET.1987.太阳能的利用[M].北京:科学技术文献出版社:28~102.
    贺平,孙刚.2008.供热工程[M].北京:中国建筑工业出版社:42~84.
    黄金,柯秀芳.2008.无机水合盐相变材料Na2SO4·10H2O的研究进展[J].材料导报,3(22):63~67.
    慧萍,苗香雯,崔绍荣.2003.温室动态温度预测模型及试验研究[J].农机化研究,10(4):182~184
    籍秀红.2007.日光温室墙体材料保温蓄热性能的测试与研究.[博士学位论文].北京:中国农业大学农学与生物技术学院.
    鞠喜林.1999.晴空条件下光照度和辐射照度的关系[J].太阳能学报,20(2):190~195.
    鞠晓慧,屠其璞,李庆祥.2005.我国太阳总辐射气候学计算方法的再讨论[J].南京气象学院学报,(04):516~521.
    康邵忠,刘晓明,高新科,等.1992.土壤-作物-大气连续水分传输的计算机模拟[J].水利学报,(3):1~12.
    李天来,齐红岩,齐明芳.2006.我国北方温室园艺产业的发展方向-现代日光温室园艺产业[J].沈阳农业大学学报,(03):265~269.
    李天来.2005.我国日光温室产业发展现状与前景[J].沈阳农业大学学报.36(2):131~138.
    李小芳.2005.日光温室的热环境数学模拟及其结构优化.[博士学位论文].北京:中国农业大学.
    李小学.2006.建筑用相变储能材料的研究进展,27(4):24~27.
    李永欣,李保明,李真,等.2004.Venlo型温室夏季自然通风降温的CFD数值模拟[J].中国农业大学学报,9(61):44~48
    李元哲,吴德让,于竹.1994.日光温室微气候的模拟与实验研究[J].农业工程学报,10(1):130~136.
    郦伟,董仁杰,汤楚宙,张淑敏.1997.日光温室的热环境理论模型[J].农业工程学报.(6):160~162
    梁浩.2008.连栋塑料温室传热模型与能耗预测研究.[硕士学位论文].武汉:华中农业大学.
    刘森元,黄远锋.1983.天空有效温度的探讨[J].太阳能学报,4(1):63~68.
    罗卫红,汪小旵,戴剑锋,等.2004.南方现代化温室黄瓜冬季蒸腾测量与模拟研究[J].植物生态学报,28(1):59~65.
    罗运俊,何梓年,王长贵,等.2005.太阳能利用技术[M].北京:化学工业出版社:2~19.
    马承伟,卜云龙,籍秀红,等.2008.日光温室墙体夜间放热量计算与保温储热性评价方法的研究[J].上海交通大学学报:自然科学版,26(5):411~415.
    毛军需.1995.太阳辐射度与光照度换算浅析[J].河南农业科学,(1)11~12.
    潘百涛,印东生.2005.中国北方地区节能日光温室研究现状及发展趋势[J].中国温室园艺,(01):15~17.
    乔正卫.2008.新型保温被的研制与应用效果研究.[硕士学位论文].陕西:西北农林科技大学.
    邵磊.2009.Venlo型温室热湿环境数值分析研究.[硕士学位论文].浙江:浙江工业大学.
    沈明卫.2000.华东地区塑料连栋温室热环境及夏季降温研究.[博士学位论文].浙江:浙江大学.
    沈学忠,张仁元.相变储能材料的研究和应用[J].节能技术,2006,5(24):460~463.
    宋贤杰,胡荣生.1997.光照度和辐照度的转换[J].光源与照明,(1):20~21.
    孙治安,施俊荣,翁笃鸣.1992.中国太阳总辐射气候计算方法的进一步研究[J].南京气象学院学报,15(2):21~29.
    孙忠富,吴毅明,曹永华,等.1993.日光温室中直射光的计算机模拟方法[J],农业工程学报,9(01):36~42.
    塔依尔,王祯丽,吕国华,等.1999.日光温室内热量收支的解析和数值模拟[J].石河子大学学报(自然科学版).3(4):303~307.
    佟国红,李保明.2005.日光温室温度环境非稳态模拟求解方法初探.2005年中国农业工程学会学术年会论文集第五分册.(1):95~99.
    佟国红,王铁良,白义奎,等.2003.日光温室墙体传热及节能分析[J].农业系统科学与综合研究.19(2):101~105.
    佟国红1,车忠仕1,白义奎1,等.2008.热量平衡法确定日光温室换气次数[J].沈阳农业大学学报,39(4):459~462
    王保国等.2009.传热学(高等教育安全工程系列“十一五”规划教材)[M].北京:机械工业出版社:48~72.
    王炳忠,张富国,李立贤.1980.我国的太阳能资源及其计算[J].太阳能学报,(1):1~9.
    王炳忠.1995.太阳能辐射资源太阳能应用[M].北京:人民教育出版社:5~27.
    王朝栋1,史为民1,裴先文2.2010.4种曲线形日光温室前屋面采光性能及其拱架力学性能的比较[J].西北农林科技大学学报(自然科学版),38(08):143~150.
    王国安1,米鸿涛2,邓天宏2,等.2007.太阳高度角和日出日落时刻太阳方位角一年变化范围的计算[J].气象与环境科学,30(supp1):161~164.
    王宏丽,邹志荣※,陈红武,等.2008.温室中应用相变储热技术研究进展[J].农业工程学报,6(24):304~307.
    王晓冬.2007.新疆新型高效节能日光温室的研制和性能分析.[博士学位论文].北京:中国农业大学农学与生物技术学院.
    王永维,苗香雯,崔绍荣,等.2003.温室地下蓄热系统换热特性研究[J].农业工程学报,19(06):248~251.
    文越华,张公正,王正刚.1999.Na2SO4·10H2O复合相变储冷体系的热力学性质[J].北京理工大学学报,19(6):778~781.
    翁笃鸣.1964.试论总辐射的气候学计算方法[J].气象学报,34(3):304~315
    翁笃鸣.1997.中国辐射气候[M].北京:气象出版社:27~48
    吴德让,李元哲,于竹.1994.日光温室地下热交换系统的实验和优化设计研究[J].农业工程学报,10(01):144~149.
    吴飞青.2010.温室冬季热环境数值分析与实验研究.[博士学位论文].浙江:浙江大学.
    吴毅明,曹永华,孙忠富,等.1992.温室采光设计的理论分析方法[J],农业工程学报,8(03):73~80.
    徐克生,王琦,王述洋,等.2004.日光温室的热平衡计算.林业机械与土木设备,7(32):24~27
    徐玲玲,沈艳华,梁斌斌等.2005.Na2SO4·10H2O和Na2HPO4·12H2O体系的相变特性,27(4):27~31.
    许金香,高丽红.2005.日光温室不同栽培茬口番茄需水量初探[J].中国农学通报,21(5):308~312.
    彦启森,赵庆珠.1986.建筑热过程[M].北京:中国建筑工业出版社:28~42.
    杨昊谕.2005.日光温室热平衡解析.吉林:吉林大学.[硕士学位论文].
    杨晓光,陈端生.1994.日光温室气象环境综合的研究(四):日光温室地温场模拟初探[J].农业工程学报.(1):150~156.
    杨昭,郁文红,张甫仁.2005.建筑物冬季太阳辐射得热分析[J].太阳能学报,26(1):104~109.
    于威,王铁良,任冰洁,等.2005.辽沈型日光温室内热平衡的建立及数值模拟.节能,8:22~24
    喻景权.2011.“十一五”我国设施蔬菜生产和科技进展及其展望[J].中国蔬菜,(2):11~23.
    章熙民,任泽霈.2011.传热学[M].第四版.北京:中国建筑工业出版社:12~34.
    张艳玲.2008.南方气候条件下光照度和辐照度的关系[J].江西农业学报,20(4):72~73.
    赵东,罗勇,高歌,等.2009.我国近50年来太阳直接辐射资源基本特征及其变化[J].太阳能学报,30(7):946~952.
    赵镇南.2008.传热学[M].北京:高等教育出版社:24~41.
    中国农业机械化科学研究院环境工程设备研究开发中心.2002.温室通风降温设计规范[M].北京:国家质量监督检验检疫总局.
    中国气象局.2003.地面气象观测规范[S].北京:气象出版社:133.
    周长吉.2003.现代温室工程[M].北京:化学工业出版社:65~102.
    邹志荣,王乃彪.1997.日光温室温度变化与热量状态分析[J].西北农业学报.6(1):58~60.
    左大康,王懿贤,陈建绥.1963.中国地区太阳总辐射的空间分布特征[J].气象学报,33(1):78~95.
    Athienitis A K, Liu C, Hawes D, et al.1997.Investigation of thethermal performance of a passive solartest-room with walllatent heat storage[J]. Building and environment,32(5):405~410.
    Boulard T, Baille A.1995.Modeling of air exchange in a greenhouse equipped with continuous roof vents.Journal of Agricultural Engineering Research,61:37~48.
    Boulard T, Wang S.2000.Greenhouse crop transpiration simulation from external climate conditions.Agricultural and Forest Meteorology,100:25~34.
    Chandra P, Albright L D,Scott N B.1981.A time dependent analysis of greenhouse thermal environments[J].Transactions of the ASAE,24(2):209~216.
    Critten D L.1986.A general analysis of light transmission in greenhouses. Journal of AgriculturalEngineering Research,33:289~302.
    De Zwart H F.1996.Analyzing energy-saving options in greenhouse cultivation using a simulationmodel.[Ph.D dissertation].The Netherlands: Agricultural University of Wageningen.
    Farid M M, Khudhair A M, Razack S A K, et al.2004.A review on phase change energy storage:materials and applications[J].Energy Conversion&management,45:1597~1615.
    Froehlien D P,et al.1979.Stead-periodic analysis of glasshouse thermal environment.Trans of theASAE,22(2):387~399
    Ghoneim A A, Klein S A, Duffie J A.1991.Analysis of collector-storage building walls using phase changematerials[J]. Solar Energy,47(1):237~242.
    Goudriaan J.1977.Crop Micrometeorology: A Simulation Study. Wageningen: Pudoc,249.
    Jacovides CP.2006.Comparative study of various correlations in estimating hourly diffuse fraction ofglobal solar radiation[J].Renewable Energy,31(1):2492~2504.
    Jaffrin A, Cadier P, Venard M.1987.La Baronne solar greenhouse of CREAT-CNRS[A]. FAO REURTechnical SeriesⅠ-on Greenhouse Heating with Solar Energy[C].Rome,192~194.
    Kimball B.1973.Simulation of the energy balance of a greenhouse.J Agri Met,11:243~260
    Kurata K, Takakura T.1991.Underground storage of solar energy for greenhouse heating. I. Analysis ofseasonal storage system by scale and numerical models [J]. Transactions of the ASAE,34(5):563~569.
    Kurklu A.1991.Energy storage applications in greenhouse by means of phase change material: a review[J].Renewable Energy,13(1):89~103.
    Lane G A.1983.Solar heat storage:latent heat materials[M]. Florida:CRC Press,5:248.
    Monsi M, Saeki T.1953.über den Lichtfaktor in den Pflanzengesellschaften und seine Bedeutung für dieStoffproduktion. Japanese Journal of Botany,14:22~52.
    Stanghellini C.1987.Transpiration of greenhouse crops: an aid to climate management.[Ph. D dissertation].The Netherlands: Wageningen Agricultural University.

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