共查询到16条相似文献,搜索用时 62 毫秒
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VLGC低温独立液罐的绝缘敷设为标准配置,其起到隔热的作用,使得外界进入的热量达到较小值,减少低温LPG液体的气化。全局导热系数k值(单位为W/(m2?℃))则是衡量绝缘系统隔热效果的重要参数。根据热力学理论,提出了一种k值的数值计算方法,并能够满足工程应用的精度。通过该方法快速计算得到的k值,可以作为合同设计阶段压缩机选型和成本预估的依据。 相似文献
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船舶交流电网在线绝缘监测装置研究 总被引:1,自引:0,他引:1
随着中国经济的飞速增长,航运行业也得到蓬勃发展。而随着船舶的大型化,自身电力系统容量越来越大,电网也越加密集,并且船舶航行也不是在稳定环境下进行,海水侵蚀比较严重,从而电力系统的绝缘故障频率较高,对绝缘故障点的迅速定位就特别重要。本文在研究了现代绝缘监测系统技术基础上,提出了一种单频信号绝缘监测技术,通过对传统双频信号监测技术的改进,简化了系统电路与软件复杂度。最后设计了基于DSP的在线监测系统装置,验证了系统的有效性。 相似文献
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One of the most important applications of adhesives in shipbuilding is the manufacturing of structural laminated materials. The application of these types of hybrid materials in a marine environment for extended periods of time and under adverse environmental conditions results in the accelerated degradation of the adhesive. Therefore, a specific experimental procedure is required to ensure the adequate performance of this adhesive bonded joint during its service life. In this study, an experimental method to analyse a vinylester adhesive in steel–adhesive–steel test specimens was applied (“mixed cantilever beam” specimens were used and mixed mode tests were carried out to obtain the fracture envelope). It was concluded that the energy release rate increased with the stress mode under dry conditions. In addition, the cohesive laws of vinylester showed that both the tangential stress and the strain are higher than the normal stress and strain. Finally, it was observed that adding distilled water to the adhesive joint for short periods of time improved its fracture strength. 相似文献
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本文系统研究了一种薄板声子晶体的低频隔声特性,薄板声子晶体由单层均质薄板和正方周期的支撑框架构成。首先,通过有限元方法研究薄板声子晶体的隔声特性和声振模态;进一步分析原包周期、薄板厚度等参数对隔声特性的影响规律;研究结果表明薄板声子晶体在低频段(100~400 Hz)具有很好的隔声特性,尤其在设计的共振频率315 Hz,相对于同质量的单层均质板,隔声量提升了约9 dB。其次,利用3D打印技术制作了试验样件并进行隔声性能测试,试验结果与理论计算结果吻合的很好。该研究为轻质隔声材料设计及低频噪声控制提供了很好的技术支撑。 相似文献
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