A review on the cooling of energy conversion and storage systems using thermoelectric modules

Exploitation of sustainable energy sources requires the use of unique conversion and storage systems,such as solar panels,batteries,fuel cells,and electronic equipment.Thermal load management of these energy conversion and storage systems is one of their challenges and concerns.In this article,the thermal management of these systems using thermoelectric modules is reviewed.The results show that by choosing the right option to remove heat from the hot side of the thermoelectric modules,it will be a suitable local cooling,and the thermoelectric modules increase the power and lifespan of the system by reducing the spot temperature.Thermoelectric modules were effective in reducing panel temperature.They increase the time to reach a temperature above 50℃ in batteries by 3 to 4 times.Also,in their integration with fuel cells,they increase the power density of the fuel cell.

The Comparison Between Finite Element Analysis and Experimental Results of the Cooling of Injection Moulds with Hot Runner System

In an injection moulding process, the mould cooling s ystem is very important as an efficient and uniform cooling effect can improve b oth the productivity and part quality. Due to the complexity of the process, muc h research on the mould cooling analysis and cooling design optimization has bee n focused on the core and the cavity, excluding other systems of injection mould s. However, the runner system introduces a considerable amount of heat into the mould. In recent years, more and more hot runner systems are being applied in th e moulding industry to save material and decrease losses of injection pressure. This raises the need to include the hot runner system in the cooling analysis. I n this paper, a photo frame part was studied. The mould was built with a hot run ner system. Two thermal sensors were installed: one measures the temperature of lateral surface of hot runner nozzle; the other measures the plastic temperature from the core side. A pressure sensor was also installed to measure the pressur e of the core impression. Cooling analysis was performed using ABAQUS, ananalysi s software based on the Finite Element Method (FEM). The assembly including core , cavity and plastic part was modeled. Heat conduction from hot runner to cavity and from polymer melt to the mould and force convection on the cooling channel surfaces were studied. The natural convection between the ambient air and the ex terior mould surface was ignored. The simulations were adjusted with the experim ental results to find out the heat input from hot runner and its influence on mo uld cooling. Finally, the optimal cooling design and optimal injection condition were obtained.

Analysis for Effects of Temperature Rise of PV Modules upon Driving Distance of Vehicle Integrated Photovoltaic Electric Vehicles

The development of vehicle integrated photovoltaics-powered electric vehicles (VIPV-EV) significantly reduces CO2 emissions from the transport sector to realize a decarbonized society. Although long-distance driving of VIPV-EV without electricity charging is expected in sunny regions, driving distance of VIPV-EV is affected by climate conditions such as solar irradiation and temperature rise of PV modules. In this paper, detailed analytical results for effects of climate conditions such as solar irradiation and temperature rise of PV modules upon driving distance of the VIPV-EV were presented by using test data for Toyota Prius and Nissan Van demonstration cars installed with high-efficiency InGaP/GaAs/InGaAs 3-junction solar cell modules with a module efficiency of more than 30%. The temperature rise of some PV modules studied in this study was shown to be expressed by some coefficients related to solar irradiation, wind speed and radiative cooling. The potential of VIPV-EV to be deployed in 10 major cities was also analyzed. Although sunshine cities such as Phoenix show the high reduction ratio of driving range with 17% due to temperature rise of VIPV modules, populous cities such as Tokyo show low reduction ratio of 9%. It was also shown in this paper that the difference between the driving distance of VIPV-EV driving in the morning and the afternoon is due to PV modules’ radiative cooling. In addition, the importance of heat dissipation of PV modules and the development of high-efficiency PV modules with better temperature coefficients was suggested in order to expand driving range of VIPV-EV. The effects of air-conditioner usage and partial shading in addition to the effects of temperature rise of VIPV modules were suggested as the other power losses of VIPV-EV.

Thermal-Hydraulic System Study of the Helium Cooled Pebble Bed (HCPB) Test Blanket Module (TBM) for ITER Using System Code RELAP5

The HCPB concept has been a European DEMO reference concept for nearly one decade. Detailed thermal-hydraulic study on the control behavior of the whole system is one of the important parts of this development. The thermal-hydraulic effect of the TBM-combined cooling circuit during a cyclic operation in ITER has been studied using the system code RELAP5. The RELAP5 is based on an one-dimensional, transient two-fluid model for the flow of a two-phase steam-water mixture that can contain noncondensable components like Helium. The RELAP5models are modified to take the cyclic operation of the circulator, heat, exchanger, bypass, valves etc in to account. A sequence of operational phases is investigated, starting from the cold state through the heating phase that brings the system to a stand-by condition, followed by typical power cycles applied in ITER. The results show that the implemented control mechanisms keep the inlet temperature to the TBM and the total mass flow rate at the required values through all phases.

A Case Study of Heat Transfer from Hot Runner Mould to the Fix Platen of the Injection-moulding Machine

In an injection moulding process, the parallelism b et ween the tie bars of the injection moulding machine is very important as it will affect the mould closing and clamping system. In recent years, more and more ho t runner systems are being applied in the moulding industry to save material and decrease the losses of injection pressure. Heat transfer from hot runner system from the fixed half which is secured in the fix machine platen could transmit s o much heat that it may cause high temperature differential between the machine fix platen and moving platen. This will cause the tie bar to become unparallel. Part quality will be compromised and the wear of the tie bar will be excessive. Overhaul of the tie bar may be necessary after a short period of time which is c ostly. This raises the need to analyze the heat transfer from the hot runner sys tem to the machine fix platen and the methods of isolating or minimizing the hea t transfer. In this case study, a photo lens article mould was used. The mould w as built with a direct hot runner nozzle system. Heat conduction from hot runner and machine screw to machine fix platen were studied based on either using high temperature heat insulating plate put in placed between the mould and the mould ing machine fix platen or drill cooling channels in the front mould clamping pla te. The high temperature insulator is very costly as it is made out of glass re inforced polymer composite material. Experimental results were obtained and anal yzed to find the best method to minimize the unwanted heat transfer using the ch eapest and most effective method.

Performance on Power,Hot and Cold Water Generation of a Hybrid Photovoltaic Thermal Module

This paper proposed a new function of photovoltaic thermal(PVT)module to produce nocturnal cool water not just only generating electrical power and hot water during daytime.Experimental tests were carried out under Chiang Mai tropical climate with a 200 Wp monocrystalline PVT module having dimensions of 1.601 m×0.828 m connected with two water tanks each of 60 L taken for hot and cool water storages.The module was facing south with 18o inclination.The electrical load was a 200 W halogen lamp.From experiments,by taking the module as a nocturnal radiative cooling surface,the cool water temperature in the cool storage tank could be reduced 2℃–3℃each night and the temperature could be reduced from 31.5℃to 22.1℃within 4 consecutive days.The cool water at approximately 23℃was also used to cool down the PVT module from noon when the PVT module temperature was rather high,and then the module temperature immediately dropped around 5℃and approximately 10%increase of electrical power could be achieved.A set of mathematical models was also developed to predict the PVT module temperature and the hot water temperature including the cool water temperature in the storage tanks during daytime and nighttime.The simulated results agreed well with the experimental data.

The Module HTGR Development in China

High Temperature Gas-cooled Reactors are recognized as a representative advanced nuclear system for the future owing to the excellent safety performance,high efficiency,multipurpose uses and hydrogen production.These type reactors are characterized by ceramic coated particle fuel,inert helium as coolant,and graphite used as moderator and reflector in core,which makes the outlet temperature of coolant reaching 950℃ even more.Under the National High Technology Program,the HTR-10 project has been successfully implemented and achieved full power operation in connection with the grid in January of 2003.HTR-10,which is the first module HTR with inherent safety feature around world,has carried out safety demonstration tests simulating the severe accident conditions in 2004.Based on the proven technologies and experience feedback during HTR-10 design,manufacture,construction and operation,a HTR-PM demonstration power plant with 200MWe power capacity sited at Rongcheng of Shandong province has been initiated.

A Review on Recent Development of Cooling Technologies for Photovoltaic Modules

When converting solar energy to electricity,a big proportion of energy is not converted for electricity but for heating PV cells,resulting in increased cell temperature and reduced electrical efficiency.Many cooling technologies have been developed and used for PV modules to lower cell temperature and boost electric energy yield.However,little crucial review work was proposed to comment cooling technologies for PV modules.Therefore,this paper has provided a thorough review of the up-to-date development of existing cooling technologies for PV modules,and given appropriate comments,comparisons and discussions.According to the ways or principles of cooling,existing cooling technologies have been classified as fluid medium cooling(air cooling,water cooling and nanofluids cooling),optimizing structural configuration cooling and phase change materials cooling.Potential influential factors and sub-methods were collected from the review work,and their contributions and impact have been discussed to guide future studies.Although most cooling technologies reviewed in this paper are matured,there are still problems need to be solved,such as the choice of cooling fluid and its usability for specific regions,the fouling accumulation and cleaning of enhanced heat exchangers with complex structures,the balance between cooling cost and net efficiency of PV modules,the cooling of circulating water in tropical areas and the freezing of circulating water in cold areas.To be advocated,due to efficient heat transfer and spectral filter characters,nanofluids can promote the effective matching of solar energy at both spectral and spatial scales to achieve orderly energy utilization.

鞍钢8m弧半径小方坯连铸机提速实践

针对8 m弧半径小方坯铸机拉速低不能满足生产要求的问题,分析了影响铸机提速的主要原因,采取了增加结晶器长度,更新结晶器供水泵,更新二冷水嘴,增大二冷管径以及优化系统温度等措施,铸机拉速由2.8 m/min提高到3.5 m/min,铸坯质量合格率达到99.95%,实现了小方坯铸机高速稳定生产。

汽车侧裙板数值成型分析及模具设计

汽车侧裙板长度约为1 m,宽度约为0.1 m,卡扣、加强筋、嵌件孔等复杂结构较多,属于大型细长复杂塑件。大型细长复杂塑件成型难度较大,需要采用数值仿真与模具设计相结合的方法,仿真、设计和验证交叉进行、相互渗透。根据产品的特点拟定了3种进浇方案,仿真结果表明,方案Ⅲ(9点进浇)翘曲变形量最小,其值为4.51 mm。通过验证方案Ⅲ的缩水性、填充时间、填充等值线、填充末端时间差及压力差等参数可知,方案Ⅲ填充均匀、末端压力一致、产品无缩水,表面无质量缺陷,为可行方案。根据方案Ⅲ进行模具设计,包括浇注系统、成型零部件、推出机构、冷却系统等。模具设计完毕后对冷却系统进行验证,结果表明,凸凹模的模温温差小于10℃,模温趋于一致,无翘曲变形风险。基于方案Ⅲ的模具设计可作为最终方案,为模具制造和生产提供方向。

圆弧抽芯注塑模具优化设计

基于圆弧抽芯注塑模具,根据塑件结构及材料性能特点,对浇口的位置及结构进行了优化设计,通过CAE模拟分析得到位于填充末端、最大壁厚处的塑件最大变形量为0.739 mm,变形量在设计允许范围内。以油缸作为驱动动力源,通过齿条驱动齿轮、内齿轮旋转,实现抽芯动作;将内齿轮设计为异形非标齿轮,减少了所占空间,实现了1模2腔布局。为解决圆弧型芯冷却水路难以加工的问题,设计的加工工序为先按照直型芯进行粗加工,钻孔加工型芯冷却水路,然后,将型芯加热弯曲为所需形状,并进行调质处理,最后对型芯进行精加工使其满足设计要求,达到了随形冷却效果。传动机构关键参数采用理论计算与CAE模拟分析相结合的法验证,测试结果表明,计算校核效率提高了约4倍。

温差电致冷组件寿命加速试验方法研究

针对现有标准中温差电致冷组件寿命试验方法缺失,通过开展不同热面温度(60℃、65℃、70℃、75℃)下的加速试验验证,分析了最大温差、电阻、最大温差工作电压等关键参数的变化,确定了加速因子,研制形成温差电致冷组件寿命加速试验方法,显著缩短了寿命试验的验证时间,满足了应用发展需求。

冷板阻热层对锂电池模组散热均匀性影响

锂电池模组温差过大引发电池间充放电、老化衰减速率不一致,致使其性能变差。为了进一步降低锂电池模组工作温差,提出一种设阻热层的新型冷板,即通过在冷板冷却液入口处与锂电池间增设阻热层增大热阻、抑制锂电池与冷板间热交换改善其散热均匀性。利用新型冷板对锂电池模组3 C放电冷却散热进行建模仿真计算,分析了并行流道、并联蛇形流道以及分叉型流道等3种不同流道冷板增设阻热层对锂电池模组放电散热均匀性影响,以及阻热层材料导热系数、厚度及覆盖面积对锂电池模组冷却散热均匀性影响。结果表明:在3种流道冷板上增设阻热层均能有效降低锂电池模组工作温差。随着阻热层材料导热系数减小,锂电池模组最高温度和温差均先减小后增加。随着阻热层厚度、阻热层覆盖面积增大,锂电池模组工作最高温度和温差均先减小后增大。采用长80 mm、宽80 mm、厚1 mm导热硅胶垫阻热层,分叉型流道冷板冷却锂电池模组3 C放电最高温度和温差降至306.55 K和4.89 K。

SiC MOSFET器件高温下最大电流导通能力评估方法

碳化硅SiC(silicon carbide)器件被认为是一种良好的耐高温半导体器件,高功率密度和高温应用需要更深入地研究损耗和散热问题。研究了SiC MOSFET功率模块在高温下的最大电流导通能力,考虑了电气性能和散热的相互关系。在建立SiC MOSFET器件的热电耦合模型配合系统散热模型的基础上,分析了热失控过程的机理。通过热电联合仿真确定了一款SiC功率模块高温下的电流容量,与实验结果相比误差约为4%,验证了所提方法的有效性。

双面散热SiC功率模块温度均匀性和开关特性评估

碳化硅MOSFET因其材料特性被广泛应用于新能源汽车的高压、高频和高功率密度场合。在考虑双面水冷散热过程,往往忽略芯片布局间距对于散热以及芯片温度均匀性的影响,未考虑芯片温度均匀性对于多芯片并联电流均匀性的影响。针对上述问题,设计一种双面水冷的封装结构,分析不同芯片布局间距对芯片温度均匀性的影响,分析不同结温及不同芯片布局对寄生参数及开关特性的影响,并针对不同芯片布局间距和不同液冷工况,采用大量仿真及响应面对比分析,验证了所提方法的有效性,为SiC功率模块封装对芯片温度均匀性及开关特性的影响提供技术方法指导和定量分析。

基于神经网络的双面散热功率模块本构热阻建模与表征

双面散热(double-sided cooling,DSC)功率模块的结-壳热阻,是其电热设计、状态监测与失效分析的关键性能指标。然而,现有的结-壳热阻模型及其测试标准,仅针对单通道传热的功率模块,难以匹配多通道传热的DSC功率模块,无法识别DSC功率模块的本构热阻信息。首先提出DSC功率模块的本构热阻模型,阐释DSC功率模块本构热阻的物理意义,分析重构单通道传热本构热阻的可行性和唯一性;其次,评估所提本构热阻与传统测试热阻的本质差异。基于商业化DSC功率模块,采用多物理场分析方法,构建DSC功率模块的热阻数据库;然后,基于神经网络学习方法和所构建的数据库,建立DSC功率模块的本构热阻模型,并通过大量训练数据和测试数据的交叉验证及多款DSC功率模块的实测结果,验证神经网络重构本构热阻的泛化能力和兼容能力,为多通道散热功率模块的热阻建模与表征,提供新的研究思路和技术途径。

强化坏路工况下冷却模块的加速耐久试验研究

提出一种加速疲劳试验功率谱编辑法。以某款商用车道路试验载荷谱为基础,通过分析各路况下的频域特征,结合冷却模块的计算模态结果,确认导致冷却模块失效的风险路况。基于采集的载荷信号计算得到各路况疲劳损伤谱分量,应用Miner线性叠理论获得总疲劳损伤,最终编辑生成台架加速试验用功率谱。通过对加速谱时域、幅值域和频域角度的对比,验证加速谱台架响应统计特征与原始谱的一致性。冷却模块的台架耐久试验表明,将振动量级提高1.85倍,通过57 h的台架试验模拟完成三种风险路段数百小时的道路试验。并复现道路试验的失效故障,验证其有效性。

基于外部冷却模块和内部凝雾模块的高位收水机械通风冷却塔性能对比研究

为了控制雾羽和节约水资源,搭建了高位收水机械通风冷却塔热态实验系统,分别对外部冷却模块(干湿联合冷却塔)和内部凝雾模块(凝雾式冷却塔)的消雾、节水及热力性能进行对比分析,研究了环境温度、循环水进水温度及循环水量对冷却塔性能的影响。结果表明:干湿联合冷却塔和凝雾式冷却塔均具有消雾和节水能力,但实现二者的消雾和节水是以降低冷却塔冷却性能为代价的;与原塔相比,干湿联合冷却塔和凝雾式冷却塔的循环水温降约降低了1.5 K;干湿联合冷却塔和凝雾式冷却塔的消雾和节水性能受运行参数的影响很大,且凝雾式冷却塔的节水量和节水率高于干湿联合冷却塔。

Case-Based Reasoning(CBR) Model for Ultra-Fast Cooling in Plate Mill

New generation thermo-mechanical control process（TMCP） based on ultra-fast cooling is being widely adopted in plate mill to product high-performance steel material at low cost. Ultra-fast cooling system is complex because of optimizing the temperature control error generated by heat transfer mathematical model and process parameters. In order to simplify the system and improve the temperature control precision in ultra-fast cooling process, several existing models of case-based reasoning（CBR） model are reviewed. Combining with ultra-fast cooling process, a developed R5 CBR model is proposed, which mainly improves the case representation, similarity relation and retrieval module. Certainty factor is defined in semantics memory unit of plate case which provides not only internal data reliability but also product performance reliability. Similarity relation is improved by defined power index similarity membership function. Retrieval process is simplified and retrieval efficiency is improved apparently by windmill retrieval algorithm. The proposed CBR model is used for predicting the case of cooling strategy and its capability is superior to traditional process model. In order to perform comprehensive investigations on ultra-fast cooling process, different steel plates are considered for the experiment. The validation experiment and industrial production of proposed CBR model are carried out, which demonstrated that finish cooling temperature（FCT） error is controlled within±25℃ and quality rate of product is more than 97%. The proposed CBR model can simplify ultra-fast cooling system and give quality performance for steel product.