The cooling structure of Ni MH batteries in hybrid electric vehicles

Focusing on Ni MH batteries used in hybrid electric vehicles (HEV), a simulation analysis of the flow and temperature fields of the cooling structure in existing batteries is carried out using computational fluid dynamics software. The results show that the temperature uniformity is poor. The uniformity of the flow and the temperature fields is improved by adjusting the baffle and battery positions, changing the tilt angle and the distance between the batteries, inserting wind plates and a coating insulation layer. The coating insulation layer achieves the best effect. Further simulation shows that the coating insulation layer method has the best effects. The results provide the design basis for thermal management program of Ni MH batteries in HEV.     

Simulation analysis on braking system of hybrid vehicle with ISG

A hydraulic braking system of the hybrid vehicle is designed based on braking force distribution and brake pressure coordination control strategy of integrated startor and generator(ISG) hybrid electric vehicle(HEV). Simulation model of hydraulic braking system has been established using AMESim software platform. Dynamic performance simulation and analysis to the key components and systems are performed. The results verify the correctness and feasibility of system program and provide evidence for designing and optimizing of HEV braking system.     

Hardware-in-loop Simulation on Regenerative Braking for Hybrid Electric Powertrain with ISG

Regenerative braking is one of main performance modes, which can reduce fuel consumption and emission. A dynamics braking control model is built for hybrid electric vehicle with ISG, an off-line simulation is completed. A regenerative braking rig in dSPACE environment is built on the hybrid electric powertrain. The tests and analyses for different speed, deceleration shift and clutch state is completed in a Hardware-In-Loop simulation, which lays a foundation for the optimization of regenerative braking control strategy for HEV.     

搭载机电控制无级变速器混合动力汽车模式切换仿真分析

通过分析机电控制无级变速器(electrical-mechanical continuously variable transmission,EM-CVT)的结构特点,提出了搭载EM-CVT混合动力汽车的传动方案,建立了动力源数值模型、EM-CVT模型,分析了混合动力系统工作模式,并针对模式切换时的冲击问题,以减小冲击度为目标,通过分析典型工况下动力源输出转矩特性和各部件的动态特性,提出了基于发动机、ISG电机、自动离合器以及EM-CVT相互协调控制策略。利用MATLAB/SIMULINK仿真平台建立混合动力传动系统动力学模型,并对典型的模式切换过程进行了仿真分析。结果表明,所提出的控制策略能够有效控制混合动力传动系统在模式切换时产生的冲击,提高了混合动力汽车的驾驶舒适性。     

Dynamics Simulation of ISG-HEV Engine During Starting

The behavior of engine automatic starting and stop under idle speed is an important working model for HEV(hybrid electric vehicle), which can avoid engine running under idle speed. So it can reduce engine fuel consumption, exhaust gas emission and wear efficiently. The ISG(integral starter/generator) motor control strategy is given by dynamic research of the HEV engine starting, based on the model and simulation of resistant characters during engine starting, then an ISG motor-engine integral control model is built up and simulated. The result shows that the ISG motor can drive engine quickly and the simulation meets well with the need of starting time.     

contact stress and steady thermal analysis of herringbone gears in a gas turbine

To obtain the distribution characteristic of contact stress and the bulk temperature on the surface of herringbone gears, parameter modeling of gears was carried out by parametric design language. A numerical simulation was given to calculate the contact stress field and the steady thermal field by combining heat transfer theory, tribology theory, and mesh theory. The distribution of contact stress, the bulk temperature and heat flux also were analyzed. The analysis results show that the distribution of the load along the contact line possesses regularity. The heat flux along the tooth depth direction decreases first and then increases. The effect of thermal conduction of the tooth is stronger than that of convective heat transfer. The conclusion indicates that the finite element emulation method can be used to estimate the transmission performance of herringbone gears.     

Development and Investigation on Duty Valve Drived Hydraulic Brake Servo System

A duty valve drove hydraulic brake servo system of HEV(hybrid electric vehicle) power transmission test rig is studied.The brake performance depends on the responses of the pressure control.A PI controller is designed through analyzing the working characterizes of the hydraulic brake system and duty valve by using rapid control prototype(RCP) tool-dSPACE,all the model and control code are successfully download to the AutoBox,and rapid control prototype experiment shows that the benefits of developing duty valve drove hydraulic brake servo system with good performance has been achieved.     

The efficiency of a Ni MH battery used in hybrid vehicles

The efficiency of the 60QNY6.5 battery is studied by testing and theoretical analysis in order to improve the control precision of hybrid electric vehicles (HEVs) and the battery useful life. A rig for testing the Ni MH batteries of HEVs is established. The data from experiments performed on the Ni MH battery are analyzed. Based on the experimental results and the temperature of the batteries, internal resistance and electromotance models of Ni MH batteries are proposed by function fitting methods. The theoretic formula for battery efficiency is deduced by the operational principle of the battery and motor, which provides theoretical basis for dynamic optimizing technology of HEV system controlling strategy.     

Condition monitoring and mistake precaution system for power strap based on photoelectric detection

Thermal environment is analyzed based on the field measurements of indoor and outdoor temperature and humidity of a typical Tibetan traditional dwelling in a village of Gannan Tibetan Autonomous Prefecture, Gansu province in winter and summer. Results show that the combination of local factors such as history, geography, climate, unique local-style dwelling houses building structure and monomer structure. The structure (envelope)of traditional Tibetan dwelling has a good thermal performance. Passive methods should be used to build thermal environment constructions. Further improvement for indoor thermal comfort conditions through comprehensive and energy-saving heating are needed.     

Coordinated pressure control of a regenerative braking system based on a hybrid electric vehicle with an integrated startor and generator

With a focus on a Changan hybrid electric vehicle (HEV) with an integrated startor and generator (ISG), strategies for braking force distribution and coordinated pressure control are put forward, and a dynamic braking control model is constructed for off     

Seismic Performance Evaluation of a Steel Reinforced Concrete Frame-Concrete Tube Structure

In order to better understand the seismic performance of the hybrid structure, numerical analysis and shaking table model testing were conducted on a real tall building constructed in Beijing. The nonlinear analytic model of the structure was established with the aid of PERFORM-3D program, and the elastoplastic time-history analysis was performed. From displacement responses and energy dissipation of the entire structure, and deformations and plastic hinge forming condition of components, the response features under different earthquake levels were obtained. Based on the predetermined allowable limits of performance indices, the seismic performance of the structure was evaluated. In the mean time, the numerical analysis results were compared with test results. Both of test results and numerical analysis results indicate that the hybrid structure has good seismic performance.     

南方建筑非透明围护结构热工与节能设计

如何兼顾冬夏两季建筑供暖空调负荷和能耗,保证室内热环境质量,确定最适宜的热工特性,是长期困扰中国南方建筑围护结构热工与节能设计的难点。通过对夏热冬冷和夏热冬暖地区建筑在采暖、空调与自然通风条件下动态热过程的分析,研究了这一地区围护结构热特性与能耗的制约关系,以及对室内热环境与建筑热稳定性的作用机理。在兼顾冬季保温与夏季隔热的情况下,将建筑全年能耗作为控制目标,从室内热环境质量、节能效果、围护结构的安全性、可靠性、经济性和实用性等角度评价目前所采用的围护结构节能技术存在的问题,提出一种适宜南方气候的建筑围护结构热特性指标及构造形式。     

Acoustics simulation and structure optimization of a motorcar exhaust muffler

Aiming at the exhaust muffler of a 244S motorcar, the acoustics field model and the flow field model are established by adopting Finite Element Method. The 3-D acoustic simulation is carried out by using software SYSNOISE, and an improvement scheme with optimized inner structure of the muffler is proposed based on the simulation. The acoustic simulation result and the bench test result of the improved muffler show that the muffling ability in middle and high-frequency of the improved structure is obviously stronger than the original structure, and the simulation result coincides well with the bench test result. Meanwhile, the flow field simulation result shows the power loss of the engine has little change, which means that the structure improvement of the original muffler is effective.     

高温胁迫对4个红掌盆栽品种生理特性的影响

为进一步了解红掌耐热机理和选择耐热育种亲本提供参考依据,以皇冠、阿瑞博、骄阳和粉冠军4个红掌盆栽品种为材料,研究了39℃高温对它们生理特性的影响,并比较其耐热性。分别测定胁迫不同时间后各品种叶片的相对电导率、相对含水量(RWC)、叶绿素含量和保护性酶活性等10个生理指标,并分析各指标随胁迫时间延长发生的变化。结果表明:随着高温胁迫时间延长,4个品种的叶片相对电导率和丙二醛含量(MDA)呈上升趋势,RWC呈下降趋势,脯氨酸含量、可溶性蛋白含量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)均呈现先上升后下降的趋势,叶绿素总含量和类胡萝卜素含量变化趋势不一致。通过10个生理指标变化趋势以及胁迫48 h后指标值大小的综合分析,可初步认为,皇冠和阿瑞博的耐热性较强,而骄阳和粉冠军的耐热性较差,与实际生产表现相一致。     

高大平房仓围护结构隔热试验

夏季高温时期,太阳对墙体的热辐射以及外界热量通过仓房围护结构的传导向粮堆传递,使墙体周边的粮温上升较快,向阳面最高部位可达30℃以上,超过了控温储粮的最高限量目标。介绍采用隔热保温材料对仓房围护结构的隔热试验,为提高高大平房仓的隔热保温性能提供科学的参考依据。     

武汉与重庆典型地质结构下的地埋管换热性能

地埋管地源热泵换热器的换热性能受到不同地质结构的影响。以武汉和重庆地区的典型地质构成为边界条件,建立了三维地埋管的单孔双U管换热模型,通过模型计算,获得了两种地质条件下的地埋管换热性能,以重庆地区的地源热泵热响应测试结果以及工程运行数据出发,对模型的计算结果进行了验证,结果表明,模型吻合度较好,可以应用于工程分析。以模型为条件,进行地质结构对换热性能的影响度分析,预测了两地地埋管地源热泵的换热性能并计算得到换热器的平均换热系数分别为武汉地区K₁=1.65（W/m·K）,重庆地区K₂=1.51（W/m·K）。     

Parameter Simulation on the Control Strategy for a Parallel Hybrid Electric Vehicle by CRUISE

The purpose of a parallel hybrid electric vehicle(PHEV) is for the best energy distribution between internal-combustion engine(ICE) and electric motor though the appropriate control strategy.It can not only keep the advantage of the ultra-low emission of electric vehicles(EV),but also take advantages of the hyperbaric energy of ICE.Simulation model for PHEV is built based on CRUISE,an auxiliary control strategy is designed,and then parameter simulation study on the control strategy is performed.The simulation results show that according to the different control requirements,the vehicle performance can be improved by adjusting!the corresponding control parameters.     

生殖生长期两优培九功能叶光反应特性

在野外条件下,利用荧光动力学分析和生理生化研究技术,对生殖生长期超高产杂交稻两优培九和大面积推广稻汕优63功能叶原初反应、电子传递和光合磷酸化水平进行系统研究,比较光反应特性。结果表明: (1) 与汕优63相比,两优培九功能叶叶绿素含量高22.90%,光合功能期长约50%,叶绿素a/b比值高36.78%;(2) 光能吸收与分配方面,两优培九功能叶单位叶面积吸收的光能不占优势,但保持高吸收的稳定期长,有活性的反应中心数量多,热耗散的能量比例较少,进入电子传递链的能量高;(3) 荧光参数分析发现两优培九PSII供体侧、受体侧和反应中心性能优良,光能吸收、传递和转化为电能效率较高;(4) 叶绿体放氧活性、电子传递链和光合磷酸化活性均显著高于汕优63,表明两优培九电能转化为活跃化学能能力强。     

中国典型储粮生态区低温储粮的优化集成方案

根据储粮生态环境,将我国分为三个典型的低温储粮生态区域,即低温区、中温区和高温区。提出了三个储粮生态区域低温储粮对仓房隔热条件和气密条件的要求及不同地区低温储粮的优化集成方案。低温区最佳的低温储粮模式是:冬季通风降温 夏季隔热 适当控温;中温区最佳的低温储粮模式是:冬季机械通风降温 夏季严格隔热 必要的控温;高温区最佳的低温储粮模式为:冬季机械通风降温或谷物冷却机降温 夏季严格隔热 谷物冷却机降温。同时给出了三个储粮生态区域低温储粮优化方案的工艺流程图。     

Research on Current Situation and Trend of Control Strategies for Hybrid Electric Vehicles

The vehicle's driving performances is determined by the control strategies and constructions of hybrid electric vehicles (HEV). The constructions of HEV are classified according to the change of state of charge of battery pack, and a study on current situation and trend of control strategies for HEV is presented in this paper. The research indicated that the current control strategies for HEV are not perfect and need further optimization. The control strategies should realize the optimum match among engine, motor, battery and transmission according to the characteristics of each component and vehicle's driving conditions. Many aspects including the fuel economy, emission, the life of battery pack, drivability, the reliability of each component and HEV's manufacture cost should be considered in the control strategies. A study on the control strategies and its optimization that take account of the aspects mentioned above is a work emphasis in the future. This paper also points out the PHEV equipped with small motor, small engine and continuously variable transmission is an ideal system construction for getting optimal fuel economy, lower emissions, steady drivability, lower manufacture cost and HEV's mass.