冻结管保温效果研究

针对当前多圈孔冻结造成的冷量分配不合理以及大圈径冻结孔布置与永久井架基础的矛盾,运用现场实验与数值模拟对比分析冻结器套管抽真空保温与聚氨酯保温的优劣性.实验表明:在目前技术水平下套管抽真空真空度不够导致隔温效果差、持续时间短;采用聚氨酯保温冻结器,管外土体降温梯度小于未保温情况,且与未保温冻结器管外温差随冻结期增长趋于...     

Study on the thermal insulation performance of a new seabed sediment fidelity sampler based on ANSYS

A new seabed sediment fidelity sampler was developed and its thermal insulation performance was studied and analyzed. The temperature distribution simulation indicated that the sample quality could be insured by using this new sampler. Based on ANSYS10, the temperature finite element model of the sample cylinder was established. According to the law of conservation of energy, the unsteady heat transmit equation of the sampler under solid-liquid coupling condition was derived, then the mathematical model calculation was carried out by using a mixed finite-element finite-difference method, and two thermal insulation methods were used. The simulation was carried out by using the thickness of the thermal insulation layer and heat conductivity as the variable parameters and the temperature distribution of the sampler and related influencing factors were obtained. Optimization analysis was conducted using the simulation data and related parameters and the magnitude ranges of the parameters were obtained that could meet the design temperature requirements. The experimental data and simulation results indicated that the results were in good agreement with the realities, and this sampler might be of value for seabed sediment sampler design and manufacture.     

防波堤复合土工薄膜防渗隔热研究

本文针对复合土工薄膜在电站防波堤作防渗和隔热体进行了研究,其防渗作用采用渗流与应力相结合的三维计算方法,给出了渗流场、应力应变等值线分布及热水渗流量,该渗流量在隔热计算中作为内部热源处理。结果表明,复合土工薄膜的防渗隔热效果是相当显著的。     

海底沉积物保真采样器保温性能的数值模拟与实验研究

提出了一种新型海底沉积物原位保真采样系统.该系统通过机械机构实现样品舱原位转移和封装.并且样品舱的保温保压性能决定着样品分析数据的真实性.依据能量守恒定律.建立了样品舱保温模型非稳态传热的导热微分方程,并用有限元法对非稳态传热进行了数模计算;根据保温模型试验和温度场变化规律仿真数据,构建了参数优化设计模型.为海底沉积物保真采样系统快速设计提供了理论依据.实验和模拟分析结果表明.所建模型与实际情况吻合较好,可以满足实际工程要求.对海底油气勘探具有重要意义.     

Laboratory test on the combined cooling effect of L-shaped thermosyphons and thermal insulation on high-grade roadway construction in permafrost regions

With the completion of the Qinghai-Tibetan Railway,economic development of related areas has been greatly accelerated.This,in return,calls for building or upgrading more roadways,especially high-grade roadways.In cold regions,the thawing of permafrost can induce settlement damage of and even failure to railway (or roadway) embankments.Thermosyphons (self-powered refrigera-tion devices that are used to help keep the permafrost cool) have proved effective in mitigating thaw settlement by maintaining the thermal stability of the embankments.However,for high-grade roadway embankments of great width,stabilizing or cooling ef-fects of traditional geotechnological measures may be limited.To enhance the cooling effect of thermosyphons,an L-shaped thermosyphon was designed.A laboratory test was carried out to study the combined cooling effect of the L-shaped thermosyphon and thermal insulation applying to roadbed construction.The angle between the evaporator and condenser sections of the L-shaped thermosyphon is 134 degrees,and the L-shaped thermosyphon was inserted into the soil at an angle of 5 degrees with the road surface.The tested results show that the L-shaped thermosyphon is effective in removing heat from a roadway in winter.When the ambient air temperature is lower than the soil temperature,the thermosyphon is active and extracts the heat in the soil around it.When the ambient air temperature is higher than the soil temperature,the thermosyphon is inactive,and no heat is in-jected into the soil through the L-shaped thermosyphon.Compared to embankments with straight thermosyphons,the inner parts of the embankments with L-shaped thermosyphons were significantly cooled.It is hoped that the present study would be useful to the application of L-shaped thermosyphons in the construction of high-grade roadways in cold regions.     

Understanding the dynamics of sustainability transitions: the Home Insulation Program

The Home Insulation Program (HIP) in Australia is an outstanding example of a contemporary attempt to intervene in a socio-technical regime. The program, implemented in 2009 under the then Australian Labor Party government led by Kevin Rudd, was targeted at stimulating the retrofit insulation industry. The objective was to both improve the energy efficiency of homes and thereby contribute to Australia’s emissions reduction targets by reducing greenhouse gas emissions and to stimulate the Australian economy at the time of the global financial crisis. The program ended early following a number of economic issues and health and safety concerns. Despite previous investigation into the HIP reviewing its design and implementation, the focus has been on economic issues and health and safety concerns. To date there has been no investigation of the HIP as a sustainability transition. This article integrates socio-technical transition theory (STTT) and political ecology (PE) approaches to analyse the HIP and identify lessons for future sustainability transition initiatives. This is achieved by illustrating the effect of regime management (RM) on the orientation of niche governance (NG) which highlights the importance of considering the RM and NG aspects of STTT with a PE approach in symmetry, in order to adequately account for political and economic contest and power relations, which are ubiquitous in environmental management governance.     

一种替代石棉的云母复合材料的研究

采用云母 粘土 碳酸盐三元矿物复合材料制成隔热绝缘抗静压材料，分析了其主要化学成分、矿物组成、电性能、机械性能和使用温度，并确定了合成云母复合材料及薄板的一般程序，在高温和较高压力条件下进行试验，云母复合材料是较好的隔热、绝缘和抗静压材料，可以在烧制人造金刚石制品过程中取代石棉。     

窗墙面积比对高层住宅外墙外保温火灾蔓延的影响分析

外墙外保温火灾发生后,窗口不仅成为火焰进入室内的通道,而且提供大量的新鲜空气,可能导致室内发生轰燃。为了研究住宅窗墙面积比（以下简称窗墙比）对火势的蔓延速率和火场温度的影响,采用了美国标准与技术研究所开发的场模拟软件FDS（火灾动力学模拟器）,模拟了不同窗墙比情况下的住宅外墙外保温火灾。分析结果表明：随着窗墙比的增大,火灾蔓延速率变快,蔓延范围增大,但峰值温度降低;起火面窗墙比为0.25时,测点峰值温度远大于对照组,起火面窗墙比为0.30时,起火房间有明显的轰燃现象,起火面窗墙比为0.35时,充分对流通风,环境冷空气进入室内,峰值温度较低;非起火面窗墙比变化基本符合上述规律,但当窗墙比过小（0.20）时,火焰难以进入室内,火势较小。     

漂珠轻质砖的隔热保温机理分析

由于粉煤灰中的空心微珠，特别是漂珠，具有低密度，成分特殊，优异的热学性质等一系列特殊的理化特性，使其漂珠轻质砖具有导热系数低，耐压强度高，导热系数随温度升高的递增率小等特点。本文从声子导热，光子导热和宏观热学性质三个方面分析了漂珠轻质砖的导热机理。     

保温板在内蒙多年冻土区道路工程中的应用

根据博—牙高速沿线气象工程地质资料、观测资料、设计资料,借助有限元软件构建了路基温度场数值计算模型,着重对不同路基填筑高度条件下XPS板对温度场的影响进行了研究。研究发现:路基填筑高度的增加和XPS保温板的应用对冻土都起到了积极的保护作用,相同路堤填筑高度下,道路运营到第20年时,XPS保温板路基多年冻土温度比碎石路基降低了约0.19℃;XPS保温板的存在使得冻土上限上移更加明显,相同路基高度下,冻土上限平均抬升量约为1.23 m,在规范规定年限内,XPS保温板路基的冻土上限均位于换填碎石中;但XPS保温板的存在加剧了阴阳坡效应的发展,综合考虑,在本段落若采用碎石路堤建议路堤高度应保持在3 m以上;若采用XPS保温板路基,建议路堤高度不超过2 m。