共查询到20条相似文献,搜索用时 250 毫秒
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分析水的汽化热实验中误差的产生原因,重点探讨蒸气导管的选择对汽化热测量的影响,为提高实验精度、减小误差提出了合理而简便的改进措施。 相似文献
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对“测定水的汽化热仪器的改进”一文的看法聂映中(江西九江师专物理系332000)《物理实验》1995年第4期“测定水的汽化热仪器的改进”一文提出由于蒸气管道中冷凝水进人冷凝器而不带来汽化热给实验结果带来较大系统误差.一般情况,蒸气质量大约5—10g,... 相似文献
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应用克拉珀龙方程获得测定低冰点液体汽化热的实验公式,自制可控温度恒温器,测量了乙二醇的汽化热.实验结果的相对误差不大于1.4%. 相似文献
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将液汽界面区域视作“表面相”,从特性函数出发,导出了液体汽化热与汽化熵的数学表达式;应用玻尔兹曼因子方程,用宏观参量T,pg,Vim的实验测量值,对物理性质炯异的水、汞、乙醇、乙醚、苯胺的汽化热与沸点汽化熵进行理论计算,得到了与实验实测值一致性优良的结果;既从理论计算角度,也从实验实例计算的角度,定量地论证了褚鲁统规则;开启了精确计算液体表面自由能及其相关物理量的方便之门. 相似文献
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测定水的汽化热仪器的改进李久永(昆明师专物理系650031)引言水的汽化热的测定是普物实验中的一个基本实验.目前通常采用的实验装置存在很大的系差.改进后的装置采用对比的方法,使部分主要系差得以修正,可取得较好的实验结果.同时,还存在一些需要完善的问题... 相似文献
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利用超声雾化器制作的冷风机,具有水雾颗粒更细,更容易进行交换,在单位时间内能获得更多汽化热,使冷风机降温效率更高的优点。 相似文献
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用固体的Einstein模型与Debye模型分别导出了相应模型的固气相变的蒸发热和蒸发压公式,并对其做了数值计算,结果表明,蒸发热与温度之间近似呈线性关系,这与工程上经验近似是一致的。 相似文献
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水和氢气、氧气在同等条件下(一个大气压,温度为25度)互相转变时自由能是相同的;同等条件下水变水蒸气时的汽化潜热和水蒸气变为水时的凝结热是相同的。利用一个刚性的绝热的容器,在海拔零米处电解水,利用氢气和氧气的混合密度小于空气密度的特点,携带一定质量的物体到数千米的高空。点燃混合气体,生成高温水蒸气。通过这个过程分析,将发现两部分能量多出。 相似文献
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差分比热实验方法是测量两个样品的比热差,具有高达万分之一的比热测量分辨率,适合测量相变时微小的比热变化及宽温区的电子比热.文章介绍了高分辨连续升温差分比热实验的测量原理和测量方法,并以铜氧化物高温超导体Y0.8Ca0.2Ba2Cu3O6+x为例,介绍了差分比热实验手段在宽温区电子比热的获得、正常态赝能隙及超导凝聚能研究等方面的应用. 相似文献
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A. N. Pavlenko E. A. Tairov V. E. Zhukov A. A. Levin A. N. Tsoi 《Journal of Engineering Thermophysics》2011,20(4):380-406
The paper presents results on experimentally investigated dynamics of boiling development and formation of film boiling zones
under stepwise heat generation on a horizontally and vertically oriented cylindrical surface in a large volume of Freon-21.
Experimental data on the expectation time and boiling temperature, the propagation velocity and structure of evaporation and
boiling fronts for different heat flux density both in saturated liquid and in subcooling conditions are obtained. Results
of experiments on investigating the nucleation forms under development of nonstationary heat release crisis caused by heat
loading on the vertical heater immersed into the volume of liquid (water, ethanol) subcooled to saturation temperature are
presented. A calculation ratio for determining the expectation time to the beginning of intense vaporization in water is proposed
and compared with experimental data obtained on surfaces with different-size roughness. Peculiarities of evolution of evaporation
fronts from incipient bubbles are investigated in the experiments with ethanol. Data on the evaporation front velocity as
a function of wall overheating are obtained. The obtained experimental data on the propagation velocity of self-sustained
evaporation fronts are compared with the known calculated data. 相似文献
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Explosion vaporization of a water layer of different thickness, induced by pulse heating in an inhomogeneous temperature field
on the surface of a flat microheater coated with a submicron silicon-carbide layer, is experimentally studied. An optical
method is used for recording the vaporization time history and dynamics of the steam blanket. Pulsed laser irradiation is
applied for high-time-resolution photography of the vaporization process. The dynamics of filling the heater surface with
the vapor phase and the lifetime of the main vapor bubble and the satellite bubble are estimated. Dependences of the vaporization
temperature on the heater temperature growth are obtained. The initial temperature is 30°C; the temperature growth rate on
the heater surfaces is about 180 MK/s. 相似文献