摘要
散热性能是影响海底观测网接驳盒供电电源长期运行的关键因素。根据热传导理论,分析金属耐压密封腔体内部电气热源的热耗散机理,推导出影响其热耗散性能的主要因素,得出腔内灌充绝缘导热油可大幅度改善散热效果,并利用Fluent分别对灌充气体、液体导热介质的腔体模型进行仿真验证。同时提出在油液内部留存一定体积气体的气液体结合的方式来缓解由于液体介质受热膨胀引起的压强升高问题,并进行1%、2%、5%、10%等4种不同空气体积率下的变压器油液因温升而导致压强升高的试验。得出结论:灌充绝缘导热油介质可改善水下密封腔的散热效果,但存在油液压强上升问题;气液结合方式可解决压强上升过高的问题,对于国产25#变压器油,大于8.8%的空气体积率可实现温升50℃时压强上升幅度低于0.1MPa。将该方法应用到海底观测网系统样机的2 kW电能变换器中,其试验测试结果与理论分析一致。
Heat dissipation performance can seriously affect the long-term operation of junction box＇s power system for seafloor observation network. The dissipation mechanism of heat generated by electrical thermal sources in sealed pressure chamber is analyzed, and its main impact factor is deduced, based on the heat conduction theory. Filling oil in chamber might greatly improve the heat dissipation performance is concluded and validated by simulations on gas and oil medium through Fluent, respectively. But problem of over-pressure that is harmful to electrical components is induced due to oil thermal expansion. A gas-liquid coexistence method by leaving an appropriate proportion of gas volume in oil is presented and theoretically analyzed based on Clapeyron theorem to alleviate the pressure. In order to validate the proposal, tests are carried out on the scenarios of 0%, 2%, 5% and 10% gas volume. Theoretical analysis and test results show that： filling the chamber with de-electrical oil could improve the heat dissipation performance, but over-pressure phenomena is induced; gas-liquid coexistence method could alleviate the oil pressure, for 25# transformer oil, a gas volume of more than 8.8% could suppress the increased pressure less than 0.1 MPa. Gas-liquid coexistence method is applied on the power supply of a prototype of seafloor observation network. Results from the laboratory test are consistent with theoretical analysis.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2013年第2期121-127,共7页
Journal of Mechanical Engineering
基金
国家高技术研究发展计划(863计划
2007AA091201)
国家985工程2期浙江大学机电系统创新平台
浙江省自然科学基金杰出青年(R1090453)
浙江省钱江人才计划(2009R10036)资助项目
关键词
海底观测网
散热
电能变换器
气液结合
Seafloor observation network Heat dissipation Power converter Gas-liquid coexistence
