共查询到20条相似文献，搜索用时 31 毫秒
1.
Semi-open heat pipes were studied experimentally in this work. A new kind of semi-open heat pipe with fluid swirl backflow
was developed on the basis of the traditional semi-open heat pipe. Heat transfer characteristics during operation and start-up
of closed heat pipe traditional semi-open heat pipe and swirl flow semi-open heat pipe were investigated. The swirl orifice's
backflow effect on enhancing the working limitation was obtained. Heat exchangers or waste heat boilers made of swirl flow
semi-open heat pipes and semi-open heat pipes have been successfully used in high or variable gas temperature engineering
applications. 相似文献
2.
Hua ZHU Bo ZHUAN Jin-jun TAN Rong-hua HONG 《浙江大学学报(A卷英文版)》2008,9(3):410-415
This paper focuses on the heat transfer performance of semi-open heat pipe which is a new type of heat pipe. After analyzing its condensation heat transfer mechanisms theoretically, several semi-open heat pipes in different length ratios and upper hole diameters are studied experimentally and compared with the same dimensions closed heat pipes. Experimental results show that the heat transfer performance of semi-open heat pipe becomes better by increasing heat transfer rate. At the first transitional point, the heat transfer performance of semi-open heat pipe approaches the level of the closed heat pipe. It is suitable to choose upper small hole about 1 mm in diameter and length ratio larger than 0.6 for the semi-open heat pipe. 相似文献
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An experimental system was set up to measure the temperature, pressure, heat transfer rate and mass flow rate in a semi-open two-phase thermosyphon. The behaviors of a semi-open two-phase thermosyphon during startup, shutdown and lack of water were studied to get complete understanding of its thermal characteristics. The variation of wall temperature, heat-exchange condition and pressure fluctuations of semi-open two-phase thermosyphons showed that the startup of SOTPT needs about 60-70 min; the startup speed of SOTPT is determined by the startup speed of the condensation section; the average pressure in the heat pipe is equal to the environmental pressure usually; the shutdown of SOTPT needs about 30~50 min; a semi-open two-phase thermosyphon has good response to lack of water accident. 相似文献
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An experimental system was set up to measure the temperature, pressure, heat transfer rate and mass flow rate in a semi-open two-phase thermosyphon. The behaviors of a semi-open two-phase thermosyphon during startup, shutdown and lack of water were studied to get complete understanding of its thermal characteristics. The variation of wall temperature, heat-exchange condition and pressure fluctuations of semi-open two-phase thermosyphons showed that the startup of SOTPT needs about 60～70 min; the startup speed of SOTPT is determined by the startup speed of the condensation section; the average pressure in the heat pipe is equal to the environmental pressure usually; the shutdown of SOTPT needs about 30～50 min; a semi-open two-phase thermosyphon has good response to lack of water accident. 相似文献
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通过对4种不同类型的铝制换热器进行性能测试,选出最优的N型2次内螺纹铝管制作空调蒸发器与冷凝器并对其流路进行优化,整机性能测试结果表明采用铝制翅片式换热器可以满足制冷性能的要求,空调管路系统采用铝是可行的。 相似文献
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管材的性价比是选择地暖用塑料管材的关键.通过对地暖用塑料管材的品种和性能的对比分析知,PB管设计应力最大、可靠性最高、原料价格也最高,但抗划痕能力相对较差;PP-R管材已很少使用;XPAP管材在使用时,要充分考虑铝层与塑料间粘结剂的耐热和老化问题;PE-X和PE-RT管材较适用于地暖;PE-RT管材的综合性价比更突出. 相似文献
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刘琼林富坤林永南 《福建工程学院学报》2020,(1):1-5
以塑料管接头为研究对象,运用Moldflow软件对两种不同形状的流道设计方案进行了模流分析对比。在模流分析结果的基础上运用CAD及UGNX软件进行了注射模的设计。结果表明,经过Moldflow的模拟分析,采用S型流道的设计能够使塑料熔体及时充满型腔,塑件表面的波状纹路及翘曲变形都明显得到改善,提高了塑料连接管的成型质量。 相似文献
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基于目前制造半导体的技术,LED输入功率中绝大多数的能量转化为热能,大约只有15%的能量转化为光能,因此必须提高LED的散热能力以保证LED的正常使用.研制了一种新型热管式大功率LED路灯散热器,该散热器的方向垂直于基板,且开设了通孔以便于液体工质在金属薄片的相邻缝隙间流通,以利于降低芯片的结温.通过对LED路灯样品温度测试实验表明安装有新型热管式散热器的LED路灯,温度变化平稳,测量到的最高温度为41.2℃. 相似文献
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Arrangement strategy of ground heat exchanger with groundwater 总被引：2，自引：2，他引：0
The orientation strategy of side pipe and the heat transfer performance of six ground heat exchangers(GHEs) were optimized by numerical simulation,with soil being treated as a porous medium.An experiment on the heat transfer of four GHEs was carried out in 2010.Results indicate that the velocity field is disturbed by GHEs.The optimal orientation strategy of side pipe is that the upward pipe is located upstream and the downward pipe downstream.The space between GHEs should be appropriately adjusted,depending on the direction and flow velocity.Groups of GHEs should be installed perpendicular to the mainstream in a single row,but if the acreage does not meet the requirements,GHEs should be installed in staggered multiple rows.Fewer GHEs parallel to the mainstream strengthen the heat transfer.Moreover,numerical results agree well with the test data,with the maximum relative error being less than 7.7%. 相似文献
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将热管系统的蒸发器作为连铸结晶器,通过测试蒸发室及熔融室内的温度,揭示热管运行温度和熔融室温度的关系。结果表明：在普通环境温度下和物质熔融温度为160℃时．热管工作温度为50-70℃,热管系统蒸发器面积和冷凝器面积之比从1：15增加到1：30时。热管工作温度降低较快,下降约23％;当面积比从1：30增加到1：60时,下降约8％：将热管系统运用于连铸生产时．增大热管系统的冷凝器面积,可以降低热管工作温度。但降低程度随面积比的增大而减小;当用于镁合金连铸时,热管的运行温度将超过100℃． 相似文献
14.
CHEN Li hong 《福建工程学院学报》2001,(Z1)
结合沿江出海口平坦地区的水文地理特点 ,提出雨水管道水力计算须按压力流考虑 ,管道水力计算的设计坡度采用水力坡降 ,管道连接采用管底平接的设计思想与计算方法 相似文献
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通过对各种新型给水管材之间水力工况的比较和分析，推得各种管径的新型给水管材与相应公称直径的镀锌钢管单位长度水头损失的比值K，由于管材间水力工况的不同，在工程设计、旅工中更换管材时，不能简单地用相同或相近管径的管材互相替代，而应重新对系统进行水力计算。 相似文献
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集热器测试系统利用两级温控,采用PID控制方法,把进水温度的漂移控制在±0.2℃以内;利用变频器采用位置式PID算法进行控制,将流量控制在±1%的精度范围内.对热管式真空管太阳能集热器进行了瞬时效率的测试,通过测试,证明了此种集热器热效率高,有广泛应用的前景. 相似文献
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孙小红徐世举苏德前 《福建工程学院学报》2019,(6):550-554
基于垂直上升立管汽液两相流型理论和冷负荷与压力(蒸发压力PZ、立管排液压力Pin)关系曲线两个角度,推理了制冷系统垂直上升回汽管内液塞形成过程,用于具体案例的液塞判断,并通过运行操作实践来消除液塞,由此验证推理和判断的合理性和适应性。分析了生产中加大压缩机载荷和热汽加压排液等措施的弊端,提出一种双罐轮流消除液塞的制冷工艺优化方案,可为液泵供液制冷系统工艺设计和运行管理提供指导。 相似文献
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田学军 《蒙自师范高等专科学校学报》2007,5(5):7-9
热胁迫将对植物造成损伤并诱导植物产生热激反应。通过适当高温热驯和其他胁迫处理,植物的耐热性将得到提高。热激蛋白、植物激素、抗氧化系统、膜脂等包含在植物耐热性中。其中,热激蛋白是植物耐热性的重要因子,而膜脂中饱和脂类的增加将提高植物的耐热性和细胞膜的稳定性。此外,脱落酸和水杨酸预处理、激活植物抗氧化系统也能提高植物的耐热性。 相似文献