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泵性能测试曲线分段最小二乘多项式拟合算法 被引量:21
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作者 汤跃 肖妹 汤玲迪 《排灌机械工程学报》 EI CSCD 北大核心 2017年第9期744-748,共5页
针对现有水泵性能测试曲线拟合算法单一、对水泵非稳定性状态不规则、马鞍形等形状数据拟合精度差、近似效果不理想甚至丢失真实试验数据特性的现状,通过比较水泵性能曲线的各种拟合方法,分析了不同拟合方法在水泵特性曲线拟合中的优缺... 针对现有水泵性能测试曲线拟合算法单一、对水泵非稳定性状态不规则、马鞍形等形状数据拟合精度差、近似效果不理想甚至丢失真实试验数据特性的现状,通过比较水泵性能曲线的各种拟合方法,分析了不同拟合方法在水泵特性曲线拟合中的优缺点,并针对特殊的水泵马鞍形性能曲线,设计了分段最小二乘多项式拟合方法.为了保证分段拟合曲线的连续可导性,在分段最小二乘拟合曲线的基础上,对各相邻分段曲线的分段点采用插值拟合的方法进行连接.最后通过试验验证,分别采用分段三阶最小二乘拟合算法和五阶最小二乘拟合算法对试验数据进行拟合,并对拟合结果进行对比分析.结果表明:采用分段最小二乘多项式的拟合方法对复杂特性曲线进行拟合,可以提高拟合曲线的拟合精度,并保证了拟合曲线的连续性. 展开更多
关键词 泵性能测试 最小二乘拟合 马鞍形特性曲线 分段曲线拟合算法 插值拟合
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Experimental assessment of two-phase bubble pump for solar water heating 被引量:5
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作者 CHUNG Han-shik WOO Ju-sik +2 位作者 SHIN Yong-han KIM Jun-hyo JEONG Hyo-min 《Journal of Central South University》 SCIE EI CAS 2012年第6期1590-1599,共10页
The research goal is to develop a new solar water heater system(SWHS) that uses a solar bubble pump instead of an electric pump.The pump is powered by the steam produced from an evacuated tube collector.Therefore,heat... The research goal is to develop a new solar water heater system(SWHS) that uses a solar bubble pump instead of an electric pump.The pump is powered by the steam produced from an evacuated tube collector.Therefore,heat could be transferred downward from the collector to a hot water storage tank.The designed system consists of two sets of heat-pipe evacuated tube collectors,a solar bubble pump installed at an upper level and a water storage tank with a heat exchanger at a lower level.Discharge heads of 1 and 5 m were tested.The bubble pump could operate at the collector temperature of about 90-100 ℃ and vapor gage pressure of 80-90 kPa.It is found that water circulation within the SWHS depends on the incident solar intensity and system discharge head.Experimental investigations are conducted to obtain the system thermal efficiencies from the hourly,daily and long-term performance tests.The thermal performance of the proposed system is compared with conventional solar water heaters.The results show that the proposed system achieves system characteristic efficiency of 10% higher than that of the conventional systems using electric pump if taking the consumption of electric power into account.And the former is a zero carbon system. 展开更多
关键词 two-phase bubble pump solar water heater system (SWHS) zero carbon
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Case study of underground pipe ground coupled heat pump system 被引量:1
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作者 郑敏 李百毅 乔振勇 《Journal of Central South University》 SCIE EI CAS 2012年第3期664-668,共5页
Aiming to give some advices on the ground coupled heat pump system design in Siehuan Province, China, a typical ground source heat pump (GSHP) system in Sichuan Province was tested in a whole operational year, and t... Aiming to give some advices on the ground coupled heat pump system design in Siehuan Province, China, a typical ground source heat pump (GSHP) system in Sichuan Province was tested in a whole operational year, and the parameters of temperature and flow rate in different parts of system were measured during this period. The seasonal energy efficiency ratio was calculated and the performance of heat pump system in summer was compared with that in winter. The result shows that the coefficient of performance of the system reaches 3.63 in summer and 3.49 in winter, respectively. The heat balance in underground rock mass is acquired basically throughout the year, and the heat accumulation in the earth tends to be zero. 展开更多
关键词 ground coupled heat pump operational test parameters measurement
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