Two methods of irrigation,drip,and sprinkler were studied to determine the response of the Javits green roof to irrigation.The control study was dry unirrigated plots.Drip irrigation consisted of irrigation tubes runn...Two methods of irrigation,drip,and sprinkler were studied to determine the response of the Javits green roof to irrigation.The control study was dry unirrigated plots.Drip irrigation consisted of irrigation tubes running through the green roof that would water the soil throughout and sprinkler irrigation used a sprinkler system to irrigate the green roof from above.In all cases,the irrigated roofs had increased the soil moisture,reduced temperatures of both the upper and lower surfaces,reduced growing medium temperatures and reduced air temperatures above the green roof relative to the unirrigated roof.The buffered temperature fluctuations were also studied via air conditioner energy consumption.There was a 28%reduction in air conditioner energy consumption and a 33%reduction in overall energy consumption between dry and irrigated plots.Values of thermal resistance or S were determined for accuracy and for this study,there was little change which is ideal.A series of infra-red and thermal probe measurements were used to determine temperatures in the air and sedum.It was determined that the sprinkler irrigation did a better job than the drip irrigation in keeping cooler temperatures within the green roof.A Mann-Whitney U test was performed to verify the variation in moisture temperatures buffering energy consumption.By getting a p-value<0.05,it indicates that the model is accurate for prediction and medium temperatures were statistically different.展开更多
The thermal property is one of the key properties for the design of the high-level radioactive waste (HLW) repository. In this study, the thermal properties transient automatic tester (HPP-F) is uesd to study the ther...The thermal property is one of the key properties for the design of the high-level radioactive waste (HLW) repository. In this study, the thermal properties transient automatic tester (HPP-F) is uesd to study the thermal conductivity of multiphase composite buffer/backfill material including the type B-Z and B-Z-P (Here B、Z、P represents bentonite、zeolite and pyrite respectively,the same as in the following.) in different dry density and moisture conditions. The results show that for the same moisture content (dry density), thermal conductivity of specimens increases as the dry density (moisture content) increases. As a result, the type B-Z-P which is highly compacted of 1.8 g/cm3 in dry density and 17.65% in moisture content performs well, it meets the requirements of the IAEA and is easy to be compacted ,so it can be recommend as a alternative material of high level radioactive waste disposal repository buffer/backfilling materials.展开更多
高放废物地质处置库缓冲/回填材料的重要作用之一是传导和散失高放废物衰变热,在膨润土中添加石英砂、石墨、花岗岩岩屑等导热性能较好的添加剂是提高缓冲/回填材料导热性能的主要方法。选用北山花岗岩岩屑为添加剂,与高庙子钠基膨润土G...高放废物地质处置库缓冲/回填材料的重要作用之一是传导和散失高放废物衰变热,在膨润土中添加石英砂、石墨、花岗岩岩屑等导热性能较好的添加剂是提高缓冲/回填材料导热性能的主要方法。选用北山花岗岩岩屑为添加剂,与高庙子钠基膨润土GMZ01组成混合材料,制备不同含水率、不同密度的试样。使用Hot Disk TPS2500s热常数分析仪测定样品的导热系数,分析其与花岗岩岩屑含量、干密度、饱和度等参数的关系,并运用多种混合物热传导模型分析预测导热系数。研究结果表明,花岗岩岩屑能够有效提高缓冲/回填材料的导热性能,混合材料的导热系数分别与其饱和度、气体体积存在线性关系;Maxwell方程能够较好预测北山花岗岩岩屑-膨润土混合材料的导热系数。展开更多
由于高放废物长期衰变放热,因此缓冲材料的热性能参数对处置库的稳定和安全运营具有重要意义。膨润土-砂混合物中石英砂的掺入可有效改善其热传导性能。本研究采用中粒石英砂作辅料,利用Hot Disk TPS2500s热常数分析仪对不同干密度、掺...由于高放废物长期衰变放热,因此缓冲材料的热性能参数对处置库的稳定和安全运营具有重要意义。膨润土-砂混合物中石英砂的掺入可有效改善其热传导性能。本研究采用中粒石英砂作辅料,利用Hot Disk TPS2500s热常数分析仪对不同干密度、掺砂率和含水率试样进行测量,分析不同参数对导热性能的影响;采用自行设计的装置对按比例缩小后的试样进行不同热源温度下的热传导模拟试验,并对缓冲层热力耦合过程进行数值模拟分析,得到了缓冲层温度、应力和位移的变化及分布情况,对比分析不同热源幅值对其分布影响的敏感程度。研究结果表明,导热系数随着干密度、掺砂率增大而增大,且含水率越高增幅越明显;热源温度越高,缓冲层温度、应力及位移的变化越大,且热力耦合条件下,径向比轴向变化相对较大。热源温度较低时处置库更为稳定。展开更多
压实纯膨润土的导热性能较差,常需添加石墨等导热性质好的材料制备混合型缓冲材料,以提高高放废物地质处置库中放射性废物衰变热的传导效率。使用Hot disk TPS2500s热常数分析仪测定不同温度条件下干燥膨润土-石墨混合材料的导热系数、...压实纯膨润土的导热性能较差,常需添加石墨等导热性质好的材料制备混合型缓冲材料,以提高高放废物地质处置库中放射性废物衰变热的传导效率。使用Hot disk TPS2500s热常数分析仪测定不同温度条件下干燥膨润土-石墨混合材料的导热系数、热扩散系数和体积比热,分析石墨含量、温度与混合材料导热性能参数的关系。试验结果表明,石墨可有效提高膨润土的导热系数、热扩散系数,添加30%~35%的石墨可使干燥高庙子(GMZ)钠基膨润土(ρd=(1.75±0.5)g/cm3)的导热系数达到与北山花岗岩相当的水平;温度对膨润土及混合材料的导热系数影响不大,混合材料的热扩散系数随温度升高而降低,体积比热随温度升高而增大。展开更多
文摘Two methods of irrigation,drip,and sprinkler were studied to determine the response of the Javits green roof to irrigation.The control study was dry unirrigated plots.Drip irrigation consisted of irrigation tubes running through the green roof that would water the soil throughout and sprinkler irrigation used a sprinkler system to irrigate the green roof from above.In all cases,the irrigated roofs had increased the soil moisture,reduced temperatures of both the upper and lower surfaces,reduced growing medium temperatures and reduced air temperatures above the green roof relative to the unirrigated roof.The buffered temperature fluctuations were also studied via air conditioner energy consumption.There was a 28%reduction in air conditioner energy consumption and a 33%reduction in overall energy consumption between dry and irrigated plots.Values of thermal resistance or S were determined for accuracy and for this study,there was little change which is ideal.A series of infra-red and thermal probe measurements were used to determine temperatures in the air and sedum.It was determined that the sprinkler irrigation did a better job than the drip irrigation in keeping cooler temperatures within the green roof.A Mann-Whitney U test was performed to verify the variation in moisture temperatures buffering energy consumption.By getting a p-value<0.05,it indicates that the model is accurate for prediction and medium temperatures were statistically different.
文摘The thermal property is one of the key properties for the design of the high-level radioactive waste (HLW) repository. In this study, the thermal properties transient automatic tester (HPP-F) is uesd to study the thermal conductivity of multiphase composite buffer/backfill material including the type B-Z and B-Z-P (Here B、Z、P represents bentonite、zeolite and pyrite respectively,the same as in the following.) in different dry density and moisture conditions. The results show that for the same moisture content (dry density), thermal conductivity of specimens increases as the dry density (moisture content) increases. As a result, the type B-Z-P which is highly compacted of 1.8 g/cm3 in dry density and 17.65% in moisture content performs well, it meets the requirements of the IAEA and is easy to be compacted ,so it can be recommend as a alternative material of high level radioactive waste disposal repository buffer/backfilling materials.
文摘高放废物地质处置库缓冲/回填材料的重要作用之一是传导和散失高放废物衰变热,在膨润土中添加石英砂、石墨、花岗岩岩屑等导热性能较好的添加剂是提高缓冲/回填材料导热性能的主要方法。选用北山花岗岩岩屑为添加剂,与高庙子钠基膨润土GMZ01组成混合材料,制备不同含水率、不同密度的试样。使用Hot Disk TPS2500s热常数分析仪测定样品的导热系数,分析其与花岗岩岩屑含量、干密度、饱和度等参数的关系,并运用多种混合物热传导模型分析预测导热系数。研究结果表明,花岗岩岩屑能够有效提高缓冲/回填材料的导热性能,混合材料的导热系数分别与其饱和度、气体体积存在线性关系;Maxwell方程能够较好预测北山花岗岩岩屑-膨润土混合材料的导热系数。
文摘由于高放废物长期衰变放热,因此缓冲材料的热性能参数对处置库的稳定和安全运营具有重要意义。膨润土-砂混合物中石英砂的掺入可有效改善其热传导性能。本研究采用中粒石英砂作辅料,利用Hot Disk TPS2500s热常数分析仪对不同干密度、掺砂率和含水率试样进行测量,分析不同参数对导热性能的影响;采用自行设计的装置对按比例缩小后的试样进行不同热源温度下的热传导模拟试验,并对缓冲层热力耦合过程进行数值模拟分析,得到了缓冲层温度、应力和位移的变化及分布情况,对比分析不同热源幅值对其分布影响的敏感程度。研究结果表明,导热系数随着干密度、掺砂率增大而增大,且含水率越高增幅越明显;热源温度越高,缓冲层温度、应力及位移的变化越大,且热力耦合条件下,径向比轴向变化相对较大。热源温度较低时处置库更为稳定。
文摘压实纯膨润土的导热性能较差,常需添加石墨等导热性质好的材料制备混合型缓冲材料,以提高高放废物地质处置库中放射性废物衰变热的传导效率。使用Hot disk TPS2500s热常数分析仪测定不同温度条件下干燥膨润土-石墨混合材料的导热系数、热扩散系数和体积比热,分析石墨含量、温度与混合材料导热性能参数的关系。试验结果表明,石墨可有效提高膨润土的导热系数、热扩散系数,添加30%~35%的石墨可使干燥高庙子(GMZ)钠基膨润土(ρd=(1.75±0.5)g/cm3)的导热系数达到与北山花岗岩相当的水平;温度对膨润土及混合材料的导热系数影响不大,混合材料的热扩散系数随温度升高而降低,体积比热随温度升高而增大。
