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离子交换树脂对氢燃料电池冷却液的影响

电源技术 2024年第10期48卷 1947-1952页

作者：李杰王峰孟洋洋贾东谭凯锋李洪智派瑞科技有限公司精细化工事业部河北邯郸056000 中国船舶集团有限公司第七一八研究所河北邯郸056027

氢燃料电池汽车常用去离子器来降低燃料电池冷却液的电导率,去离子器中的离子交换树脂对冷却液的影响是值得研究的。研究了燃料电池循环冷却系统中使用的离子交换树脂对冷却液缓蚀剂的影响,包括离子交换树脂对缓蚀剂苯并三氮唑(BTA)和... 详细信息

氢燃料电池汽车常用去离子器来降低燃料电池冷却液的电导率,去离子器中的离子交换树脂对冷却液的影响是值得研究的。研究了燃料电池循环冷却系统中使用的离子交换树脂对冷却液缓蚀剂的影响,包括离子交换树脂对缓蚀剂苯并三氮唑(BTA)和甲基苯并三氮唑(TTA)的吸附行为,BTA吸附速率的影响因素,考察了燃料电池汽车运行时冷却液中BTA的浓度变化和电导率。研究结果表明,相同条件下,树脂用量、工作温度和搅拌速度均能够增大树脂对冷却液中BTA的吸附速率。吸附BTA饱和后的离子交换树脂仍能继续吸附冷却液中的离子,并解析出BTA。氢燃料电池冷却液装车运行2500 km后,BTA浓度基本保持不变,维持在600 mg/L左右。研究结果可以为氢燃料电池冷却液的开发以及去离子器的使用提供指导。

关键词：氢燃料电池冷却液离子交换树脂苯并三氮唑甲基苯并三氮唑吸附

Suppression of vortex-induced vibration of a circular cylinder by Lorentz force

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Science China(Physics,Mechanics & Astronomy) 2011年第12期54卷 2248-2259页

作者： ZHANG Hui FAN BaoChun li hongzhi Science and Technology on Transient Physics Laboratory Nanjing University of Science and Technology Nanjing 210094 China

The electro-magnetic control of vortex-induced vibration (VIV) of a circular cylinder is investigated numerically in the exponential-polar coordinates attached on the moving cylinder for Re=150 in the paper. Compared with the fixed cylinder, the vibration of cylinder leads to the shift of stagnation point, the shear layer strength and the inertial force, which affects the hydrodynamic forces on the cylinder. The effects of the instantaneous wake geometries and the corresponding cylinder motion on the hydrodynamic forces for one entire period of vortex shed are discussed in the drag-lift phase diagram. The Lorentz force for controlling the vibration cylinder is classified into the field Lorentz force and the wall Lorentz force. The field Lorentz force decreases the lift oscillation, and in turn, suppresses the VIV, whereas the wall Lorentz force has no effect on the lift.

关键词： flow control vortex-induced vibration electro-magnetic control hydrodynamic force

life Prediction Based on Transient Dynamics Analysis of Van Semi-trailer with Air Suspension System

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Chinese Journal of Mechanical Engineering 2011年第3期24卷 372-379页

作者： li liang SONG Jian HE lin ZHANG Mengjun li hongzhi State Key Laboratory of Automotive Safety and Energy Tsinghua University Beijing 100084 China

The early fatigue damage in the van-body of the semi-trailer is often caused by the unique mechanical characteristics and the dynamic impact of the *** traditional finite element method with static strength analysis cannot support the fatigue design of van-body;thus,the dynamics analysis should be adopted for the endurance *** accurate dynamics model to describe the transient impacts of all kinds of uneven road and the proper system transfer functions to calculate the load transfer effects from tire to van-body are two critical factors for transient dynamics *** order to evaluate the dynamic performance,the dynamics model of the trailer with the air suspension is brought *** the analysis method of the power spectral density （PSD） is set up to study the transient responses of the road dynamic *** transient responses transferred from axles to van-body are calculated,such as dynamic stress,dynamic RMS acceleration,and dynamic load *** on the above dynamic responses,the fatigue life of van-body is predicted with the finite element analysis （FEA） *** the test parameters of the trailer with air suspension,the simulation system with Matlab/Simulink is constructed to describe the dynamic responses of the impacts of the tested PSD of the vehicle axles,and then the fatigue life is predicted with FEA *** simulated results show that the vibration level of the van-body with air suspension is reduced and the fatigue life is *** real vehicle tests on different roads are carried out,and the test results validate the accuracy of the simulation *** proposed fatigue life prediction method is effective for the virtual design of auto-body.

关键词： van-body air suspension system transient dynamics power spectral density (PSD) life prediction

Road Friction Estimation under Complicated Maneuver Conditions for Active Yaw Control

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Chinese Journal of Mechanical Engineering 2009年第4期22卷 514-520页

作者： li liang li hongzhi SONG Jian YANG Cai WU Hao The State Key Laboratory of Automotive Safety and Energy Tsinghua University Beijing 100084 China

Road friction coefficient is a key factor for the stability control of the vehicle dynamics in the critical conditions. Obviously the vehicle dynamics stability control systems, including the anti-lock brake system（ABS）, the traction control system（TCS）, and the active yaw control（AYC） system, need the accurate tire and road friction information. However, the simplified method based on the linear tire and vehicle model could not obtain the accurate road friction coefficient for the complicated maneuver of the vehicle. Because the active braking control mode of AYC is different from that of ABS, the road friction coefficient cannot be estimated only with the dynamics states of the tire. With the related dynamics states measured by the sensors of AYC, a comprehensive strategy of the road friction estimation for the active yaw control is brought forward with the sensor fusion technique. Firstly, the variations of the dynamics characteristics of vehicle and tire, and the stability control mode in the steering process are considered, and then the proper road friction estimation methods are brought forward according to the vehicle maneuver process. In the steering maneuver without braking, the comprehensive road friction from the four wheels may be estimated based on the multi-sensor signal fusion method. The estimated values of the road friction reflect the road friction characteristic. When the active brake involved, the road friction coefficient of the braked wheel may be estimated based on the brake pressure and tire forces, the estimated values reflect the road friction between the braked wheel and the road. So the optimal control of the wheel slip rate may be obtained according to the road friction coefficient. The methods proposed in the paper are integrated into the real time controller of AYC, which is matched onto the test vehicle. The ground tests validate the accuracy of the proposed method under the complicated maneuver conditions.

关键词： active yaw control road friction coefficient estimation sensor fusion

Real-time Tire Parameters Observer for Vehicle Dynamics Stability Control

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Chinese Journal of Mechanical Engineering 2010年第5期23卷 620-626页

作者： li liang li hongzhi ZHANG Xiaolong HE lin SONG Jian State Key Laboratory of Automotive Safety and Energy Tsinghua University Beijing 100084 China

The performance of the vehicle dynamics stability control system（DSC） is dominated by the accurate estimation of tire forces in *** characteristics of tire forces are determined by tire dynamic states and parameters,which vary in an obviously large scope along with different working ***,there have been many methods based on the nonlinear observer to estimate the tire force and dynamic parameters,but they were only used in off-line analysis because of the computation complexity and the dynamics differences of four tires in the steering maneuver conditions were not considered *** paper develops a novel algorithm to observe tire parameters in real-time controller for *** algorithm is based on the sensor-fusion technology with the signals of DSC sensors,and the tire parameters are estimated during a set of maneuver *** calibrated tire parameters in the control cycle are treated as the elementary states for vehicle dynamics observation,in which the errors between the calculated and the measured vehicle dynamics are used as the correcting factors for the tire parameter observing *** test process with a given acceleration following a straight line is used to validate the estimation method of the longitudinal stiffness;while the test process with a given steering angle is used to validate the estimated value of the cornering *** ground test result shows that the proposed algorithm can estimate the tire stiffness accurately with an acceptable computation cost for real-time controller only using DSC sensor *** proposed algorithm can be an efficient algorithm for estimating the tire dynamic parameters in vehicle dynamics stability control system,and can be used to improve the robustness of the DSC controller.

关键词： tire longitudinal stiffness cornering stiffness vehicle dynamics stability

Design Method of an Ocean Induction Coupling Chain Communication System that Resists the Multipath Effect of a Seawater Channel

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Journal of Ocean University of China 2021年第1期20卷 87-93页

作者： ZHENG Yu LU Yanfang FEI Chen li hongzhi School of Electronics and Information Engineering Tianjin Polytechnic UniversityTianjin 300387China National Ocean Technology Center Tianjin 300112China

In this study,a mathematical model of multipath channels is established,and the delay parameters of 10-path models are calculated at 300 m.A multipath-channel hardware simulator based on a field programmable gate array(FPGA)is designed and verified at 100 k Hz,200 k Hz,500 k Hz,1 MHz,and 24 MHz transmission *** to the characteristics of the ocean induction coupling chain channel,the orthogonal frequency-division multiplexing(OFDM)algorithm parameters are designed by referring to the wireless communication *** appropriate length cyclic prefix(CP)is added in the OFDM symbol to resist the multipath effect of the seawater channel,and the FPGA hardware transceiver based on the OFDM algorithm is *** hardware platform of the ocean induction coupling chain communication system is developed to resist the multipath effect of the seawater channel and tested at 24 *** experimental results show that 800 ns is the best CP length for the developed system,which can effectively resist the multipath effect,with a signal-to-noise ratio above 24 d B and a bit error rate below 1%.This study provides a hardware simulation test platform and an effective method to resist the multipath effect of a seawater channel and improve the transmission performance of the seawater channel.

关键词： ocean induction coupling chain communication system multipath-channel hardware simulator OFDM FPGA hardware platform

Algorithm for Calculating Torque Base in Vehicle Traction Control System

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Chinese Journal of Mechanical Engineering 2012年第6期25卷 1130-1137页

作者： li hongzhi li liang SONG Jian WU Kaihui QIAO Yanjuan liU Xingchun XIA Yongguang State Key Laboratory of Automotive Safety and Energy Tsinghua University Beijing 100084 China Chang'an Automotive Engineering General Research Institute Chongqing 400023 China

Existing research on the traction control system（TCS） mainly focuses on control methods, such as the PID control, fuzzy logic control, etc, aiming at achieving an ideal slip rate of the drive wheel over long control periods. The initial output of the TCS （referred to as the torque base in this paper）, which has a great impact on the driving performance of the vehicle in early cycles, remains to be investigated. In order to improve the control performance of the TCS in the first several cycles, an algorithm is proposed to determine the torque base. First, torque bases are calculated by two different methods, one based on states judgment and the other based on the vehicle dynamics. The confidence level of the torque base calculated based on the vehicle dynamics is also obtained. The final torque base is then determined based on the two torque bases and the confidence level. Hardware-in-the-loop（HIL） simulation and vehicle tests emulating sudden start on low friction roads have been conducted to verify the proposed algorithm. The control performance of a PID-controlled TCS with and without the proposed torque base algorithm is compared, showing that the proposed algorithm improves the performance of the TCS over the first several cycles and enhances about 5% vehicle speed by contrast. The proposed research provides a more proper initial value for TCS control, and improves the performance of the first several control cycles of the TCS.

关键词： traction control system torque base torque control initial value

POSITIVE SOLUTIONS FOR p-LAPLACIAN DYNAMIC EQUATIONS ON TIME SCALES

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Applied Mathematics(A Journal of Chinese Universities) 2007年第1期22卷 69-77页

作者： Geng Fengjie Zhu Deming li hongzhi Department of Mathematics East China Normal University Shanghai 200062 China College of Science Agricultural University of Hebei Baoding 071000 China.

The three-point boundary value problems of p-Laplacian dynamic equations on time scales are investigated. By using Krasnosel＇skii＇s fixed-point theorem and fixed-point index theorem, criteria are achieved for the existence of at least one, two or 2n positive solutions. Furthermore, some examples are included to illustrate the main theorems.

关键词： time scale jump operator three-point boundary value problem dynamic equation cone.

Study on Flow Characteristics of a Turbulent Boundary Layer and Vortex Structure of High Pressure Guide Vanes in SCO_2 Turbines

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Journal of Thermal Science 2019年第3期28卷 571-584页

作者： HAN Wanlong WANG Yueming FENG Zhenping li hongzhi YAO Mingyu ZHANG Yifan R&D Center Xi'an Thermal Power Research Institute Co. Ltd. School of Energy and Power Engineering Xi'an Jiaotong University

In order to further understand the aerothermodynamic performance and flow loss mechanism of SCO_2 turbines, RANS equations and an SST Turbulence Model were chosen for a numerical study on the secondary flow and vortex structure of cascades using the commercial software CFX. The dimensionless vorticity analysis method was used to study the flow characteristics of the logarithmic layer and viscous sublayer in high pressure guide vane cascades. The new vortex structure and formation mechanism of the vortices were given and analyzed. Simulation results indicated that during the motion of the boundary layer in the cascades, the logarithmic layer and viscous sublayer obtain the different rotational direction vorticity, respectively. The endwall logarithmic layer and pressure side leg of the horseshoe votex gradually develop into the passage vortex, with the endwall viscous sublayer gradually developing into the corner viscous sublayer vortex II and the endwall viscous sublayer vortex I. The endwall viscous sublayer that rolled by the passage vortex is encountered with the upstream-side and radial boundary layer of the vane at the suction separation line, forming the suction separation line vortex beside the passage vortex. A pair of radial transition vortices are formed between the wake and the main stream.

关键词： SCO2 turbine vortex structure dimensionless vorticity logarithmic layer viscous sublayer secondary flow