The ride comfort experimental assessment of crawler off-road vehicle is relatively overlooked, and is expensive and difficult to execute with higher and higher ride comfort performance requirements. To trade off betwe...The ride comfort experimental assessment of crawler off-road vehicle is relatively overlooked, and is expensive and difficult to execute with higher and higher ride comfort performance requirements. To trade off between precise and cost, an experimental method based on the similitude theory is proposed. Under the guidance of the similitude theory, a 1：5 crawler power chassis scale model equipped with a kind of variable stiffness suspension system is used. The power spectrum density（PSD）, the root mean square（RMS） of weighed acceleration, peak factor, average absorbed power（AAP） and vibration dose value（VDV） are selected as ride comfort evaluation indexes, and tests results are transformed via similarity indexes to predict the performance of full-scale power chassis. PSD shows that the low-order natural frequency of the vertical natural frequency（z axis） is 1.1 Hz, and the RMS, AAP and VDV values indicate the ride comfort performance of this kind of power chassis is between the ＂A little uncomfortable＂ and ＂Rather uncomfortable＂. From the results, low-order vertical natural frequency, obtained by PSD, validates that the similarity relationship between two models is satisfied, and 1：5 scale model used in experiment meets the similarity relationship with the full-scale model; consequently, the ride comfort prophase evaluation with the 1：5 scale model is feasible. The attempt of applying the similitude theory to crawler vehicle ride comfort test study decreases the cost and improves the test feasibility with sufficient test precise.展开更多
蓄热电采暖因其用电时段可调、运行经济灵活,已经成为西北地区冬季取暖期重要的灵活性调节资源。合理地规划蓄热电采暖容量可以有效提高风电消纳水平,提升系统的运行经济性。为此,该文提出一种考虑热舒适度弹性和提升风电消纳的蓄热电...蓄热电采暖因其用电时段可调、运行经济灵活,已经成为西北地区冬季取暖期重要的灵活性调节资源。合理地规划蓄热电采暖容量可以有效提高风电消纳水平,提升系统的运行经济性。为此,该文提出一种考虑热舒适度弹性和提升风电消纳的蓄热电采暖双层优化配置方法。通过引入热感觉平均标度预测(predicted mean vote,PMV)指标来量化用户的热舒适度,根据热舒适度弹性的限定范围确立热平衡区间约束。在分别分析系统风电消纳以及热舒适度弹性对蓄热电采暖容量配置的影响的基础上,建立兼顾风电消纳和热舒适度弹性的蓄热电采暖双层优化配置模型。上层以风电供热系统年化总成本最小为目标,下层以系统典型日运行成本最小为目标,通过上下层迭代求解蓄热电采暖最优容量配置以及系统运行方案。最后,基于实际算例验证了所提的蓄热电采暖配置方法可在保证供暖舒适度的基础上提升风电消纳水平和系统整体经济性。展开更多
基金Supported by Special Fund for Argo-scientific Research in the Public Interest,China(Grant No.201203024)National Natural Science Foundation of China(Grant No.51175498)
文摘The ride comfort experimental assessment of crawler off-road vehicle is relatively overlooked, and is expensive and difficult to execute with higher and higher ride comfort performance requirements. To trade off between precise and cost, an experimental method based on the similitude theory is proposed. Under the guidance of the similitude theory, a 1：5 crawler power chassis scale model equipped with a kind of variable stiffness suspension system is used. The power spectrum density（PSD）, the root mean square（RMS） of weighed acceleration, peak factor, average absorbed power（AAP） and vibration dose value（VDV） are selected as ride comfort evaluation indexes, and tests results are transformed via similarity indexes to predict the performance of full-scale power chassis. PSD shows that the low-order natural frequency of the vertical natural frequency（z axis） is 1.1 Hz, and the RMS, AAP and VDV values indicate the ride comfort performance of this kind of power chassis is between the ＂A little uncomfortable＂ and ＂Rather uncomfortable＂. From the results, low-order vertical natural frequency, obtained by PSD, validates that the similarity relationship between two models is satisfied, and 1：5 scale model used in experiment meets the similarity relationship with the full-scale model; consequently, the ride comfort prophase evaluation with the 1：5 scale model is feasible. The attempt of applying the similitude theory to crawler vehicle ride comfort test study decreases the cost and improves the test feasibility with sufficient test precise.
文摘蓄热电采暖因其用电时段可调、运行经济灵活,已经成为西北地区冬季取暖期重要的灵活性调节资源。合理地规划蓄热电采暖容量可以有效提高风电消纳水平,提升系统的运行经济性。为此,该文提出一种考虑热舒适度弹性和提升风电消纳的蓄热电采暖双层优化配置方法。通过引入热感觉平均标度预测(predicted mean vote,PMV)指标来量化用户的热舒适度,根据热舒适度弹性的限定范围确立热平衡区间约束。在分别分析系统风电消纳以及热舒适度弹性对蓄热电采暖容量配置的影响的基础上,建立兼顾风电消纳和热舒适度弹性的蓄热电采暖双层优化配置模型。上层以风电供热系统年化总成本最小为目标,下层以系统典型日运行成本最小为目标,通过上下层迭代求解蓄热电采暖最优容量配置以及系统运行方案。最后,基于实际算例验证了所提的蓄热电采暖配置方法可在保证供暖舒适度的基础上提升风电消纳水平和系统整体经济性。
