Research on the technical scheme of multi-stack common rail fuel cell engine based on the demand of commercial vehicle

At present,most fuel cell engines are single-stack systems,and high-power single-stack systems have bottlenecks in meeting the power requirements of heavy-duty trucks,mainly because the increase in the single active area and the excessive number of cells will lead to poor distribution uniformity of water,gas and heat in the stack,which will cause local attenuation and reduce the performance of the stack.This paper introduces the design concept of internal combustion engine,takes three-stack fuel cell engine as an example,designs multi-stack fuel cell system scheme and serialized high-voltage scheme.Through Intelligent control technology of independent hydrogen injection based on multi-stack coupling,the hydrogen injection inflow of each stack is controlled online according to the real-time anode pressure to achieve accurate fuel injection of a single stack and ensure the consistency between multiple stacks.proves the performance advantage of multi-stack fuel cell engine through theoretical design,intelligent control and test verification,and focuses on analyzing the key technical problems that may exist in multi-stack consistency.The research results provide a reference for the design of multi-stack fuel cell engines,and have important reference value for the powertrain design of long-distance heavy-duty and high-power fuel cell trucks.

高输出功率温差发电系统的研究

本文旨在研发某种高效率、高输出功率的温差发电技术;并对该技术在热电设备应用中的多种工作条件下的功率进行了系统的研究。首先讨论对温差发电模块及系统进行了建模、设计和建造;其次汇报一种最先进的热电模块测量仪器的研究成果,该仪器可对关键热电特性参数进行现场实时测量。此外,对多种热电特性进行了原位实时表征,这些包括效率、电流电压(即I-V)曲线、功率电压(P-V)曲线、外力响应曲线以及功率与温度(P-T)响应曲线。经过深入研究并建造了大功率热能收集装置;对热电工程设备做出了重要的创新,并很好应用于尾气热能的废热收集利用的研发项目。最后,研究结果显示,三级联设备的仿真计算效率为19%以上,双级联的实验测试效率为10.6%以上。这些结果与现有技术相比,其输出功率和热电效率都得到了很大的提高。

Progress and challenges in multi-stack fuel cell system for high power applications:Architecture and energy management

With the development of fuel cells,multi-stack fuel cell system(MFCS)for high power application has shown tremendous development potential owing to their obvious advantages including high efficiency,durability,reliability,and pollution-free.Accordingly,the state-of-the-art of MFCS is summarized and analyzed to advance its research.Firstly,the MFCS applications are presented in high-power scenarios,especially in transportation applications.Then,to further investigate the MFCS,MFCS including hydrogen and air subsystem,thermal and water subsystem,multi-stack architecture,and prognostics and health monitoring are reviewed.It is noted that prognostics and health monitoring are investigated rarely in MFCS compared with previous research.In addition,the efficiency and durability of MFCS are not only related to the application field and design principle but also the energy management strategy(EMS).The reason is that the EMS is crucial for lifespan,cost,and efficiency in the multi-stack fuel cell system.Finally,the challenge and development potential of MFCS is proposed to provide insights and guidelines for future research.

Remaining Useful Life Prediction for a Multi-stack Solid Oxide Fuel Cell System with Degradation Interactions

Due to the constraints of manufacturing and materials,high-power plants cannot rely on only one solid oxide fuel cell stack.A multi-stack system is a solution for a highpower system,which consists of multiple fuel cell stacks.A short lifetime is one of the main challenges for the fuel cell before largescale commercial applications,and prognostic is an important method to improve the reliability of fuel cells.Different from the traditional prognostic approaches applied to single-stack fuel cell systems,the key problem in multi-stack prediction is how to solve the correlation of multi-stack degradation,which can directly affect the accuracy of prediction.In response to this difficulty,a standard Brownian motion is added to the traditional Wiener process to model the degradation of each stack,and then the probability density function of the remaining useful life(RUL)of each stack is calculated.Furthermore,a Copula function is adopted to reflect the dependence between life distributions,so as to obtain the remaining useful life for the whole multi-stack system.1 The simulation results show that compared with the traditional prediction model,the proposed approach has a higher prediction accuracy for multi-stack fuel cell systems.

Recent developments of ther-moelectric power generation

One form of energy generation that is expected to be on the rise in the next several decades is thermoelectric power generation (TEPG) which converts heat directly to electricity.Compared with other methods,TEPG possesses the salient features of being compact,light-weighted,noiseless in operation,highly reliable, free of carbon dioxide emission and radioactive substances. Low current conversion efficiency and high cost,however,are some of the disadvantages. Use of TEPG is therefore justified to hightech applications associ- ated with aerospace,military operation,tel-communication and navigation,instrumentation of unmanned vehicles moni- tored from remote locations.More-over,TEPG does not con- tribute to the depletion of natural resource and pollution of the environment such as climate warming that has been a concern in recent times.This work is concerned with provid- ing an overview of the state of the art of TEPG with empha- ses placed on assessing its current and potential applica- tion.Pointed out are the ways to fabricate high performance thermoelectric material,a hurdle to overcome for the en- hancement of TEPG device efficiency.