检索结果-南通市图书馆

Experimental research on the heating performance of a single cylinder refrigerant injection rotary compressor heat pump with flash tank

引用

Science China(Technological Sciences) 2018年第12期61卷 1814-1823页

作者： SUN JinFei zhu dongsheng YIN YingDe LI XiuZhen Guangzhou Institute of Energy Conversion Chinese Academy of Sciences Guangzhou 510640 China Key Laboratory of Renewable Energy Chinese Academy of Sciences Guangzhou 510640 China Guangdong Key Laboratory of New and Renewable Energy Research and Development Guangzhou 510640 China University of Chinese Academy of Sciences Beijing 100049 China

A single cylinder rotary compressor was applied in the refrigerant injection air-source heat pump to improve the heating performance in cold regions. In this study, the performance of an R410 A single cylinder rotary compressor vapor injection(SCRCVI) system was measured and analyzed by varying the compressor frequency f and injection pressure Pi njat the ambient temperature To d=–10°*** experimental results indicated that an optimum injection pressure to gain the maximum COP_h (coefficient of performance) existed in the SCRCVI cycle. However, the maximum COP_h of the SCRCVI system decreased as the increase of the frequency, and the maximum COPhwas even lower than that of the CSVC system at high compressor frequency. Therefore, in view of the energy saving and emission reduction, the SCRCVI system should be switched to single stage compression system when the heating capacity demand could be satisfied at high compressor frequency f. Compared to the conventional single-stage vapor compression(CSVC) system, refrigerant injection could enhance the heating capacities and COP_h by 28.2% and 7.91%, respectively. The average total mass flow rate of the SCRCVI system was 24.68% higher than that of the CSVC system. As the SCRCVI system worked at the optimum injection pressure, the variation trends of the different system parameters were investigated in detail. These trends were reliably used to optimize the refrigerant injection system design and the control strategy. The parameter of(P_(inj)–P_s) could be adopted as the signals to control the opening of the upper stage electronic expansion valve EEV1.

关键词： rotary compressor refrigerant injection DC (direct current) inverter heat pump heating performance injection pressure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A New Two-Stage Tunable Space-Time Adaptive Detector

引用

Journal of Beijing Institute of Technology 2023年第1期32卷 124-130页

作者： Xiaojing Su Da Xu dongsheng zhu Institute of Acoustics Chinese Academy of SciencesBeijing 100190China.University of Chinese Academy of SciencesBeijing 100049China Institute of Acoustics Chinese Academy of SciencesBeijing 100190China

In order to improve the rejection capability of mismatched interferer signals,a new two-stage detector is proposed under homogeneous scenarios with unknown covariance matrix,which is obtained by cascading the adaptive matched filter(AMF)detector and the enhanced RAO(EnRAO)*** new detector has constant false alarm performance,and the closed-form expression of probability of false alarm and probability of detection is *** performance of the new detector is assessed,and analyzed in comparison with other *** results show that,the proposed detector can provide enhanced rejection capability in the case of mismatch,but the performance of the detector is slightly lost under the condition of matching.

关键词： adaptive detection constant false alarm rate(CFAR) two-stage tunable adaptive matched filter(AMF) enhanced RAO(EnRAO)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Thermal-Hydraulic Characteristics of Twisted Elliptical Tube Bundle in Staggered Arrangement

引用

Journal of Thermal Science 2021年第6期30卷 1925-1937页

作者： LI Xiuzhen WANG Lin FENG Rong WANG Zhanwei zhu dongsheng Institute of Building Energy and Thermal Science Henan University of Science and TechnologyLuoyang 471023China CAS Key Laboratory of Renewable Energy Guangzhou 510640China School of Mechanical Engineering Shaanxi Key Laboratory of Industrial AutomationShaanxi University of TechnologyHanzhong 723001China

Based on experimental data,numerical simulations by turbulent air flowing across staggered tube bundle composed of twisted elliptical tube(TET)with constant tube wall temperature are conducted in present *** study on the thermal-hydraulic characteristics of air crossflow in TET bundles is investigated with physical parameters and Reynolds number(Re).The results show that spiral channels created by spiral deformation of TETs have a diversion effect on the air flow,which changes the flow direction of the air near the tube *** air in the near wall region is a three-dimensional flow,consisting of a flow perpendicular to the normal direction of the elliptical cross section and a spiral flow along the helicoid on the downstream side and the upstream *** the interaction of the spiral channels makes the two flows and their mixing more *** excellent heat transfer performance of staggered TET bundles is confirmed by the comparison of the comprehensive heat transfer performance with that of circular tube *** average Nusselt number(Nu)increases with the increase of the aspect ratio(A/B)and with the increase of Re while decreases as the twist pitch(S)*** average Euler number(Eu)increases as A/B increases,while it decreases as Re increases and as S *** to the fact that the suitable correlations for staggered TET bundles are not reported,correlations for Nu and Eu obtained from experimental data and numerical results are presented in the multiple forms.

关键词： twisted elliptical tube heat transfer enhancement pressure drop performance cross flow

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Robust Space-Time Adaptive Track-Before-Detect Algorithm Based on Persymmetry and Symmetric Spectrum

引用

Journal of Beijing Institute of Technology 2024年第1期33卷 65-74页

作者： Xiaojing Su Da Xu dongsheng zhu Zhixun Ma Institute of Acoustics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Underwater monopulse space-time adaptive track-before-detect method,which combines space-time adaptive detector(STAD)and the track-before-detect algorithm based on dynamic programming(DP-TBD),denoted as STAD-DP-TBD,can effectively detect low-speed weak ***,due to the complexity and variability of the underwater environment,it is difficult to obtain sufficient secondary data,resulting in a serious decline in the detection and tracking performance,and leading to poor robustness of the *** this paper,based on the adaptive matched filter(AMF)test and the RAO test,underwater monopulse AMF-DP-TBD algorithm and RAO-DP-TBD algorithm which incorporate persymmetry and symmetric spectrum,denoted as PSAMF-DP-TBD and PS-RAO-DP-TBD,are proposed and compared with the AMF-DP-TBD algorithm and RAO-DP-TBD algorithm based on persymmetry array,denoted as P-AMF-DP-TBD and *** simulation results show that the four methods can work normally with sufficient secondary data and slightly insufficient secondary data,but when the secondary data is severely insufficient,the P-AMF-DP-TBD and P-RAO-DP-TBD algorithms has failed while the PSAMF-DP-TBD and PS-RAO-DP-TBD algorithms still have good detection and tracking capabilities.

关键词： space-time adaptive detection track before detect robustness persymmetric property symmetric spectrum AMF test RAO test

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

LQTTrack:Multi-Object Tracking by Focusing on Low-Quality Targets Association

引用

Computers, Materials & Continua 2024年第10期81卷 1449-1470页

作者： Suya Li Ying Cao Hengyi Ren dongsheng zhu Xin Xie Henan Key Laboratory of Big Data Analysis and Processing School of Computer and Information EngineeringHenan UniversityKaifeng475001China College of Information Science and Technology&Artificial Intelligence Nanjing Forestry UniversityNanjing210037China School of Computer Nanjing University of Posts and TelecommunicationsNanjing210023China

Multi-object tracking(MOT)has seen rapid improvements in recent ***,frequent occlusion remains a significant challenge in MOT,as it can cause targets to become smaller or disappear entirely,resulting in lowquality targets,leading to trajectory interruptions and reduced tracking *** from some existing methods,which discarded the low-quality targets or ignored low-quality target ***,with a lowquality association strategy(LQA),is proposed to pay more attention to low-quality *** the association scheme of LQTTrack,firstly,multi-scale feature fusion of FPN(MSFF-FPN)is utilized to enrich the feature information and assist in subsequent data ***,the normalized Wasserstein distance(NWD)is integrated to replace the original Inter over Union(IoU),thus overcoming the limitations of the traditional IoUbased methods that are sensitive to low-quality targets with small sizes and enhancing the robustness of low-quality target ***,the third association stage is proposed to improve the matching between the current frame’s low-quality targets and previously interrupted trajectories from earlier frames to reduce the problem of track fragmentation or error tracking,thereby increasing the association success rate and improving overall multi-object tracking *** experimental results demonstrate the competitive performance of LQTTrack on benchmark datasets(MOT17,MOT20,and DanceTrack).

关键词： Low-quality targets association strategy feature fusion multi-object tracking tracking-by-detection

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The impact of HS radicals on the measured rate constant of H_2S with OH radicals

引用

Chinese Science Bulletin 2010年第26期55卷 2951-2955页

作者： WANG HaiTao zhu dongsheng WANG WeiPing MU YuJing Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

The rate constant for the reaction of OH radicals and hydrogen sulfide (H2S) was studied in different bath gases (including N2, air, O2 and He) by using relative technique at 298 K. The small difference of the measured rate constants between N2 and those with the presence of O2 suggested possible influence of HS self reaction. Further experiments with NOx presence for scavenging HS demonstrated this assumption. The rate constant of (5.48±0.12) ×10-12 cm3 molecule-1 s-1 obtained with 4.09 ×10-4 mol m3 NO presence may be accurate for estimating the atmospheric lifetime of H2S. The results provided circumstantial evidence that the rapid reaction of HS with N2O is suspected.

关键词： OH自由基速率常数硫化氢 HS 氮氧化物反应常数可能影响快速反应

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evolution of the microstructure and solute distribution of Sn-10wt% Bi alloys during electromagnetic field-assisted directional solidification

引用

Journal of Materials Science & Technology 2019年第4期35卷 568-577页

作者： Zhe Shen Minghu Peng dongsheng zhu Tianxiang Zheng Yunbo Zhong Weili Ren Chuanjun Li Weidong Xuan Zhongming Ren State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering Shanghai University

The effects of forced flows at different velocities on microstructure and solute distribution during the directional solidification of Sn-10 wt% Bi alloys under a simultaneous imposition of a transverse static magnetic field(TSMF) and an external direct current(DC) have been investigated experimentally and numerically. The experimental results show that the solid-liquid interface will gradually become sloping with the increase of the forced flow velocity when the thermoelectric magnetic convection(TEMC)dominates the forced flow at solidification front. However, the interface will gradually become planar as the flow velocity further increases when the electromagnetic convection(EMC) dominates the forced flow. Moreover, when the flow velocity gradually increases, the primary dendrite spacing decreases from384 to 105 μm accordingly. The simulation results show that the solute distribution at the two sides of the sample can be significantly changed by the forced flow at solidification front. The rejected solute will be unidirectionally transported to one side of the sample along the TEMC(a low-velocity forced flow),thereby causing the formation of a sloping interface. However, the rejected solute will be returned back along the EMC(a higher-velocity force flow), which results in a planar interface. Furthermore, the solute content at the two sides of the sample under the forced flows at different velocities was measured. The results are in good agreement with the simulation results, which shows that the solute content difference between the two sides of the sample reaches the maximum when a 0.5 T TSMF is applied, while the solute content difference decreases to zero with a simultaneous application of a 0.5 T TSMF and a 1.6 × 10~5 A/m^2 external DC.

关键词： Directional solidification Sn-Bi alloy Forced flow Solute distribution Numerical simulation Electromagnetic field

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Durbin test with enhanced detection performance to mismatched signal

引用

Chinese Journal of Acoustics 2016年第4期35卷 406-415页

作者： HAO Chengpeng SHI Bo XU Da CHEN Dong zhu dongsheng Institute of Acoustics Chinese Academy of Sciences

This paper deals with the problem of detecting a signal whose amplitude is a scaling factor in the presence of homogeneous Gaussian noise with unknown covariance *** no uniformly most powerful test exists for the problem at hand,we devise and assess a detection strategy based on the well-known Durbin test design *** closed-form expressions for the probabilities of false alarm and detection of the Durbin test are derived,which show that it bears a constant false alarm rate property against the noise covariance *** the analysis stage,the performance of the new receiver is assessed,also in comparison with some classical adaptive detectors,both in matched and in mismatched signal *** results show that the proposed detector achieves a visible performance improvement in the presence of severe steering vector mismatch,while maintaining an acceptable detection loss for matched signal.

关键词： test Durbin test with enhanced detection performance to mismatched signal CFAR

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

管壳式换热器壳程高黏度流体的传热强化

引用

化工学报 2005年第8期56卷 1451-1455页

作者：朱冬生蒋翔华南理工大学传热强化与过程节能教育部重点实验室化工与能源学院广东广州510640

It is a key factor to increase heat transfer coefficien t of high viscosity fluid in the shell side for making a high performance cooler.T he heat transfer and flow resistance performance of trapezoid fin tube high visc osity fluid cooler with helical or segmental baffles were studied, and compared with the heat transfer coefficient of low-fin-tube cooler with segmental baffl es. Experimental results indicated that heat transfer film coefficient in the sh ell side of trapezoid fin tube cooler with entire helical baffles was 60% more h igher than that of low-fin-tube cooler with segmental baffles,and pressure dr op was lower by 40%. Heat transfer film coefficient in the shell side of trapezo id fin tube cooler with entire helical baffles was 20% more higher than that of trapezoid-fin tube cooler with segmental baffles, and pressure drop was lower b y 50%.Heat transfer film coefficient in the shell side of trapezoid fin tube coo ler with entire helical baffles was 10% higher than that of trapezoid fin tube c ooler with sectional helical baffles, and pressure drop was lower by 19%.Heat tr ansfer film coefficient in the shell side of trapezoid fin tube cooler with segm ental baffles was 30% more higher than that of low-fin-tube cooler with segmen tal baffles, and pressure drop remained unchanged.

关键词：管壳式换热器高黏度流体螺旋折流板梯形翅片管强化传热

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

简支梁桥横向地震反应研究

引用

土木工程学报 2000年第4期33卷 27-31页

作者：朱东生兰州铁道学院

用有限元方法对简支梁桥的横向地震反应按全桥模型进行了计算分析，并与我国公路规范方法的结果进行了比较。讨论了桥长、主梁横向刚度、不同计算模型等因素对简支梁桥横向地震反应的影响。研究表明：对于简支梁桥的横向抗震计算，应该... 详细信息

用有限元方法对简支梁桥的横向地震反应按全桥模型进行了计算分析，并与我国公路规范方法的结果进行了比较。讨论了桥长、主梁横向刚度、不同计算模型等因素对简支梁桥横向地震反应的影响。研究表明：对于简支梁桥的横向抗震计算，应该采用全桥模型计算；我国现行公路及铁路抗震规范中的简化计算方法误差较大。

关键词：简支梁桥横向地震力规范地震反应

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：