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垂直埋管热湿传递线源模型的建立及其计算条件 被引量:9
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作者 张玲 陈光明 黄奕沄 《太阳能学报》 EI CAS CSCD 北大核心 2007年第2期141-145,共5页
现有的土壤传热模型忽略了水分迁移对传热的影响,根据质量与能量守恒原理,在原有的垂直埋管土壤源热泵一维线源模型上发展了传热传湿数学模型,并对模型中土壤的各参数进行了分析,为下一步的数值模拟计算以及进一步研究土壤含水率对传热... 现有的土壤传热模型忽略了水分迁移对传热的影响,根据质量与能量守恒原理,在原有的垂直埋管土壤源热泵一维线源模型上发展了传热传湿数学模型,并对模型中土壤的各参数进行了分析,为下一步的数值模拟计算以及进一步研究土壤含水率对传热影响奠定基础。 展开更多
关键词 土壤源热泵 热湿传递 土壤含水率 线源理论
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现场测试地层平均热物性参数方法初探——以北京某工程地源热泵系统地层热物性测试评价工程为例 被引量:1
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作者 韩华 孙保卫 +2 位作者 王峰 毛向阳 周复宗 《城市地质》 2007年第2期27-31,共5页
地层热物性参数是地源热泵系统地下换热器设计所需要的非常重要的参数,热物性参数的大小对钻孔的数量及钻孔的深度均有显著的影响,进而影响地源热泵系统的初投资。笔者以北京某工程地源热泵系统地层热物性测试评价工程为例,阐述了现场... 地层热物性参数是地源热泵系统地下换热器设计所需要的非常重要的参数,热物性参数的大小对钻孔的数量及钻孔的深度均有显著的影响,进而影响地源热泵系统的初投资。笔者以北京某工程地源热泵系统地层热物性测试评价工程为例,阐述了现场测试获取平均热物性参数的测试方法和原理,并通过建立传热模型,利用参数估算法计算了工程场区的热物性参数。为验证结果的可靠性,又采用了线源理论对测试数据进行计算并将计算结果与参数估算法进行了分析比较。最后,笔者对两种计算方法的求解方法和适用条件进行了归纳总结。由于目前地层热物性参数确定方法还很不成熟,可借鉴的经验不多,所以笔者提出的热物性参数确定方法只是尝试性的探索,还有待今后的实践检验和进一步的理论研究工作。 展开更多
关键词 现场测试 地层热物性 地源热泵系统 参数估算法 线源理论
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地源热泵垂直埋管换热器地下热阻及管长的分析 被引量:1
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作者 余红海 《制冷与空调(四川)》 2007年第4期48-53,共6页
讨论了地源热泵垂直埋管换热器传热过程及其数学模型,引入热阻的概念,将埋管换热器管内流体与土壤的传热过程分为钻孔内和钻孔外两部分。阐述了利用传统的线源和柱源理论求解钻孔外热阻的方法,并结合实例对影响埋管换热器管长的因素进... 讨论了地源热泵垂直埋管换热器传热过程及其数学模型,引入热阻的概念,将埋管换热器管内流体与土壤的传热过程分为钻孔内和钻孔外两部分。阐述了利用传统的线源和柱源理论求解钻孔外热阻的方法,并结合实例对影响埋管换热器管长的因素进行了对比分析,可供工程设计计算使用。 展开更多
关键词 地源热泵 垂直埋管换热器 线源理论 柱源理论 热阻 管长
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土壤源热泵地下换热器热阻模型的对比分析 被引量:2
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作者 刘俊 《建筑热能通风空调》 2011年第6期75-79,共5页
本文基于经典的线源理论和圆柱源理论,求解了土壤源热泵地下换热器的各项热阻。结合热阻概念,建立热平衡方程求解了单位深度换热量。分析了系统运行时间、管内水流速、回填材料导热系数、冬夏季进口水温和岩土类型对热阻和单位深度换热... 本文基于经典的线源理论和圆柱源理论,求解了土壤源热泵地下换热器的各项热阻。结合热阻概念,建立热平衡方程求解了单位深度换热量。分析了系统运行时间、管内水流速、回填材料导热系数、冬夏季进口水温和岩土类型对热阻和单位深度换热量的影响,为地源热泵系统的优化设计提供参考。 展开更多
关键词 土壤源热泵 地下换热器 线源理论 圆柱源理论 热阻 单位深度换热量
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稠油冷采井产量动态分析综合模型 被引量:1
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作者 刘向东 赵刚 +1 位作者 黄颖辉 刘平礼 《特种油气藏》 CAS CSCD 北大核心 2013年第5期107-109,156,共3页
稠油冷采井早期存在泡沫油黏度增大和蚓孔快速生长的特征,导致其与常规油井相比,产量特征有较大差异,无法用传统产量递减模型进行分析。为此,基于线源理论,提出了一套用于稠油冷采井动态的虬孔模拟研究的综合模型。研究表明,蚓孔增长速... 稠油冷采井早期存在泡沫油黏度增大和蚓孔快速生长的特征,导致其与常规油井相比,产量特征有较大差异,无法用传统产量递减模型进行分析。为此,基于线源理论,提出了一套用于稠油冷采井动态的虬孔模拟研究的综合模型。研究表明,蚓孔增长速度和增长期在产量动态上的特征非常明显。通过拟合稠油冷采井现场数据,可计算出蚓孔增长速度和增长期,以便用于冷采井的合理井距、加密井井位的确定,以及冷采后期优化调整和稠油冷采井早中期产量的预测。 展开更多
关键词 稠油冷采 产量动态 综合模型 蚓孔 泡沫油 线源理论
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Correlation between the Change in the Number of Apis mellifera Worker Bees and Nectar Secretion of Nectariferous Plants
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作者 余玉生 张祖芸 +2 位作者 宋文菲 卢焕仙 王艳辉 《Agricultural Science & Technology》 CAS 2014年第1期116-118,136,共4页
[Objective] This study aimed to clarify the correlation between changes of Apis mel ifera and the nectar secretion characteristics of nectariferous plants. [Method] Considering the nectar secretion characteristics of ... [Objective] This study aimed to clarify the correlation between changes of Apis mel ifera and the nectar secretion characteristics of nectariferous plants. [Method] Considering the nectar secretion characteristics of major and auxiliary nec-tariferous plants, six Apis mel ifera colonies were selected for measure the number of eggs, larvae, pupae and adult bees from Jan. to Dec. in 2012; based on that, their annual change curves were also plotted. [Result] The results showed that there were three peaks of the total number of A. mel ifera workers throughout the year:the first occurred on May 15th, with bees developed into an ideal population for col-lecting pomegranate nectar, and the second and third peaks occurred on July 15th and Oct. 15th, respectively, with bees developed into an ideal population for col ect-ing E. ciliate (Thuab) Hyland. [Conclusion] Prevention of Varroa jacobsoni should be carried out with two or more types of acaricides at the late nectar flow stages of the two nectariferous plants(pomegranate and E. ciliate (Thuab) Hyland) when there was a nectar deficiency. Prevention of Tropilaelaps clareae should be timely per-formed with sublimed sulfur in conjunction with acaricides. This study provides a theoretical basis for the high-quality and high-yielding production of honey, as wel as for the product safety. 展开更多
关键词 Apis mellifera Number of worker bees Nectariferous plants CURVE Theoretical basis
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关于土壤耦合垂直U型管换热器传热公式计算的若干问题探讨
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作者 万嘉凤 左涛 《发电与空调》 2014年第4期31-35,17,共6页
土壤耦合型地源热泵系统中垂直U型管长度的计算存在多种传热理论和计算方法,在应用中应根据工程实际进行理论、计算方法以及计算参数的选择,以保证设计既经济又可靠。
关键词 土壤耦合型地源热泵 垂直U型换热器 负荷聚合 线源理论 圆柱源理论
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Dynamic overlapped spectrum allocation based on potential game in cognitive radio networks 被引量:1
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作者 贾亚男 Yue Dianwu 《High Technology Letters》 EI CAS 2014年第4期401-408,共8页
In order to make full use of wireless spectrum resources,the behavior of cognitive radio(CR)for dynamic spectrum allocation is analyzed based on the game theoretic framework.The traditional spectrum allocation schemes... In order to make full use of wireless spectrum resources,the behavior of cognitive radio(CR)for dynamic spectrum allocation is analyzed based on the game theoretic framework.The traditional spectrum allocation schemes consider the spectrum allocation among independent frequency bands only,without taking into account mutually overlapped frequency bands.For this reason,an optimal allocation etiquette is defined to promote the cross characteristic of the frequency bands in a dynamic spectrum allocation model.New interference operator and interference temperature constraints are introduced in order to realize calculation of the interference,and the corresponding spectrum allocation scenario can be further formulated as a potential game.Based on the characteristic of dynamic selection using the game theory and the interference avoidance rule of interference temperature,the robustness of CR networks is increased and the scenario is more suitable for the dynamic changing of actual wireless communication and energy saving communication systems.Simulation results show that the signal to interference and noise ratio(SINR) level can be significantly improved through the optimal allocation of any available spectrum.The utilization rate of spectrum and throughput of overall CR networks are increased by fully utilizing the spectrum resources in the dynamic spectrum allocation model. 展开更多
关键词 cognitive radio (CR) game theory spectrum allocation nash equilibrium
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Chinese Water Resource Management and Application of the Harmony Theory 被引量:1
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作者 左其亭 马军霞 陶洁 《Journal of Resources and Ecology》 CSCD 2013年第2期165-171,共7页
Chinese water resource management (CWRM) has passed through four stages: infancy, initial development, rapid development, and formation. In the last of these stages some problems persist and will affect management ... Chinese water resource management (CWRM) has passed through four stages: infancy, initial development, rapid development, and formation. In the last of these stages some problems persist and will affect management performance. CWRM was a decentralised, imperfectly codified and weakly implemented system that lacked a sound market policy, rational water prices, water conservation awareness, technical support and a performance appraisal system. The government of China proposed two new strategies in 2009: the Three Red Lines and the Interconnected River System Network (IRSN). This paper analyses these two strategies and reflects on new CWRM concepts. Both strategies strive for the sustainable utilisation of water resources and human-water harmony. The concepts, quantification method and application of harmony theory to water resources management is discussed. Applications of harmony theory to water resources management include (i) harmony between humans and nature; (ii) a harmony strategy for water resources management; (iii) a rational allocation model for water resources among different areas and departments based on harmony theory; (iv) harmony-based water allocation issues associated with transboundary rivers; (v) harmony-based interbasin water transfer problems; and (vi) harmony-based control of pollution discharge. We conclude by discussing how harmony theory and its applications provide an appropriate pathway for water resource management in China. 展开更多
关键词 Chinese water resource management (CWRM) harmony theory Three Red Lines Most StrictWater Management System (MSWRMS) Interconnected River System Network (IRSN)
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