共查询到19条相似文献,搜索用时 281 毫秒
1.
2.
3.
4.
柴国荣 《墙材革新与建筑节能》2011,(6):33-35
基于Ansys软件建立数学模型,计算分析不同厚度、不同结构和布局的定形相变材料与混凝土组成墙体的节能效果。结果表明,定形相变材料越厚,墙体内表面温度随外界温度变化幅度越小,能够有效降低室内空调设备能耗;定形相变材料厚度一定时,不同的定形相变材料结构和布局对墙体内表面温度的波动影响较小,在节能降耗上差别不大。 相似文献
5.
基于Ansys软件,对混凝土和外贴式定形相变材料组成的相变墙体进行了计算研究,研究结果表明:100 mm厚的混凝土墙体分别外贴安装10 mm和20 mm定形相变材料,都起到了较好的节能效果,分别减少了室内制冷装置16%和29%的制冷量;定形相变材料的相变温度在一定范围内的小幅变化对墙体传热性能和节能性能影响不明显。 相似文献
6.
采用ANSYS软件对混凝土外贴定形相变材料组成的相变墙体的节能特性进行了模拟研究,并对其计算结果进行了分析,结果表明:定形相变材料的相变温度在一定程度上影响墙体节能性能和相变材料能力的发挥,需要根据气候条件进行合理的选择。 相似文献
7.
低温定形相变材料在相变墙体中应用的可行性研究 总被引:12,自引:3,他引:12
低温定形相变材料是应用于建筑物墙体中的理想储能材料,它可增加墙体的蓄热能力,节约建筑能耗。研究了2种以高密度聚乙烯为支撑材料的低温定形相变石蜡在不同石蜡含量下材料的相变潜热、相变温度、均匀性和稳定性,并讨论了石蜡在材料中的最佳含量范围。研究结果证明了石蜡用于相变墙体中的优越性和可行性,为日后实际应用提供依据。 相似文献
8.
9.
10.
11.
The high thermal storage capacity of phase change material (PCM) can reduce energy consumption in buildings through energy storage and release when combined with renewable energy sources, night cooling, etc. PCM boards can be used to absorb heat gains during daytime and release heat at night. In this paper, the thermal performance of an environmental chamber fitted with phase change material boards has been investigated. During a full-cycle experiment, i.e. charging–releasing cycle, the PCM boards on a wall can reduce the interior wall surface temperature during the charging process, whereas the PCM wall surface temperature is higher than that of the other walls during the heat releasing process. It is found that the heat flux density of the PCM wall in the melting zone is almost twice as large as that of ordinary wall. Also, the heat-insulation performance of a PCM wall is better than that of an ordinary wall during the charging process, while during the heat discharging process, the PCM wall releases more heat energy. The convective heat transfer coefficient of PCM wall surface calculated using equations for a normal wall material produces an underestimation of this coefficient. The high convective heat transfer coefficient for a PCM wall is due to the increased energy exchange between the wall and indoor air. 相似文献
12.
Roland Krippner 《Bauphysik》2005,27(3):173-180
Investigation of the application of PCM in wood‐lightweight‐concrete in buildings. Wood‐lightweight‐concrete (WLC) is a compound material, consisting of cement, shavings from sawmill, water and additives. The material is characterised by good properties of heat and noise insulation as well as strength. Within the framework of R&D‐projects the combination of wood‐lightweight‐concrete with organic phase change materials (PCM) was examined. A lot of experimental tests have been done, models in different scales have been built. Finally, parallel preliminary practise‐tests have been conducted. Mixtures with different density (between 1000 and 1450 kg/m3) have been investigated (strength up to 20 N/mm2 and thermal insulation l between 0.28 and 0.50 W/mK). Furthermore in a thermal building simulation three different partition walls (in addition to a reference case, one with WLC and the other with WLC+PCM) of a south‐orientated office‐room have been studied. An increase in heat capacity of wood‐lightweight‐concrete with PCM leads to a reduction of overheating in summer, considering external shading and adequate change of air in the night. The obtained results showed, that composite materials from wood, inorganic binders have interesting options for the use in building constructions. WLC with phase change materials may provide additional functional and constructive advantages, i. e. lighter and thinner outer wall elements with concurrent better thermo‐dynamic material properties. 相似文献
13.
分别将2种三维金属骨架(面中心法金属骨架,圆柱交叉金属骨架)加入纯相变材料(石蜡)制备复合相变材料1,2。采用数值模拟方法,模拟相变传热过程,分析加热过程纯相变材料,复合相变材料的温度变化,液相率变化,速度场分布。容纳石蜡的方腔长×宽×高为5 cm×2 cm×5 cm,方腔左壁面为加热面,温度为65℃,其他壁面绝热。纯相变材料,复合相变材料的初始温度均为25℃。相同加热时间,复合相变材料的平均温度明显高于纯相变材料。对于纯相变材料,热量向方腔右侧壁面传递缓慢,加入金属骨架可加速热量向方腔右侧壁面传递。相同加热时间,复合相变材料的液相率明显高于纯相变材料。在加热初期,复合相变材料1液相率更高,添加面中心法金属骨架更有利于加速相变蓄热。纯相变材料内部传热由导热和自然对流传热共同作用形成。复合相变材料内部的传热也是由导热与自然对流传热共同作用形成。相同加热时间,复合相变材料1的液相区域要大于复合相变材料2,且相变更加均匀。对于纯相变材料,熔化过程中,石蜡的流动主要集中在加热面附近及左上角,角化现象明显。对于复合相变材料,在接近完全熔化及完全熔化状态,固态石蜡基本熔化完成,方腔内液态石蜡温度基本趋于一致,自然对流强度减弱,复合相变材料1,2内石蜡的流动并不明显。与复合相变材料2相比,复合相变材料1的速度场分布更加均匀。面中心法金属骨架的综合性能更优,适合作为相变材料的强化传热金属骨架。 相似文献
14.
15.
16.
An experimental and numerical simulation study of the application of phase change materials (PCMs) in building components is presented for thermal management of a passive solar test-room. The experimental study was conducted in an outdoor test cell constituted of two small rooms separated with a wall containing PCM. A specific wall made of hollow glass bricks filled with PCM was studied. Three PCMs were tested: fatty acid, paraffin, and salt hydrate whose melting temperatures are 21 °C, 25 °C and 27.5 °C respectively.Indoor and outdoor temperatures were measured with thermocouples. Ten fluxmeters located at the centre of each wall allowed us to measure the heat fluxes across the walls. Tests were carried out in real climatic conditions.A one-dimensional numerical model has been developed to simulate the transient heat transfer process in the walls. Reasonable agreement between the simulation and the experimental results was observed. 相似文献
17.
脂肪酸分子合金相变材料的热稳定性 总被引:5,自引:1,他引:4
以癸酸/肉豆蔻酸分子合金为例,研究了脂肪酸分子合金作为相变材料的热稳定性.利用差示扫描量热技术(DSC)测定了经过56,112,200,400,710次热循环后相变材料的相变温度和相变热.加速热循环实验结果表明:随着热循环次数的增加,相变材料的相变温度和相变热的变化很小,具有很好的热稳定性.分析了利用脂肪酸类相变材料制作空调储能装置的应用效果,发现该装置在储、放能过程中,可使室内温度基本稳定在20℃左右,从而节约能源,减少用户电费支出,并显著降低建筑物室内温度波动,营造健康舒适的室内热环境. 相似文献
18.
分别将两种金属翅片(翅片1、翅片2)加入纯相变材料(石蜡),制备复合相变材料1、复合相变材料2。容纳石蜡的方腔长×宽×高为20 mm×10 mm×20 mm,翅片1的长×宽×高为15 mm×10 mm×1 mm,翅片2是在翅片1的基础上增加6个直径为3 mm通孔,金属翅片设置在方腔内部,垂直于左壁面平行布置。石蜡的初始温度为298.15 K,相变开始之前石蜡为固态。方腔左壁面为加热面,温度恒定为338.15 K,其余各面为绝热面。采用有限元软件COMSOL Multiphysics模拟方腔内石蜡的相变过程,分析加热过程中纯相变材料、复合相变材料的液相率分布、液相率随时间变化、速度场分布。纯相变材料内,在导热和对流换热的共同作用下,石蜡从左上角开始熔化直至右下角石蜡完全熔化。方腔内金属翅片的加入可改善熔化过程的均匀性,缩短了熔化时间。纯相变材料、复合相变材料1、复合相变材料2石蜡完全熔化时间分别为302、106、90 s,复合相变材料1、2比纯相变材料完全熔化时间缩短了约64%、70%,复合相变材料2比复合相变材料1完全熔化时间缩短了约15%。在石蜡熔化初期,主要以导热为主,复合相变材料... 相似文献