Energy distribution analyses of an additional traction battery on hydrogen fuel cell hybrid electric vehicle
Introduction
Automotive producers and industry members are strongly encouraged to re-generation on electrified versions by considering alternative energy and propulsion solutions due to sharp decrements of fossil fuels and higher greenhouse gas emission. Although electric vehicles have zero emission pollution while on-road driving, grid electricity which powered to electric vehicles is obtained from fossil resources power plants. When this situation is taken into consideration, in automotive sector, new researches and produced prototypes have been added to the industrial and academic area. Fuel cell electric vehicles are playing an important role in this corner. After 2015 United Nations Climate Change Conference (Paris meeting); the main goal of limiting global warming at 2 °C, all related participants in world tended to discussing the importance of hydrogen in all areas. Zero-carbon energy behavior and limitless source of it, hydrogen, is playing as a critical factor in energy sector.
According to energy agencies reports; in a global perspective, the largest and growing source of CO2 emissions is causing from transportation sector with 28% totally [1]. Alternative fuels and different energy source systems which driven the vehicles, should help to minimize this rate. Therewithal, in automotive sector, all stakeholders started to search the most exact solution for minimizing the fuel consumption and emissions with maximizing the performance and range capabilities. Last two decades, the road map of this solution addressed the two important key answers. First one is using hydrogen and the second one is electrification in transportation.
Hydrogen (H2) and its derivatives have been used in automotive sector as a fuel since last century. In road transportation, generally, H2 fueled conventional internal combustion engines (ICE) in gaseous form. Author’s previous studies were related with this phenomenon [[2], [3], [4]]. As a general opinion and finding from Refs. [[2], [3], [4]] results; H2 effected positively to engine performance in terms of torque and power due to its heating value. In the way of entrance to engine, gas form of H2 which enriched the air in intake manifold, increases the air/fuel ratio that it is end with lesser fuel consumption. Additionally H2 reduced the emissions (except NOx) because of carbon absence of its nature. Nevertheless, a detailed comparative table is given from Ref. [5], which figured the influences of H2 in ICEs.
Therewithal, hydrogen sources were varied. Possible hydrogen sources were studied so much researchers and investigators. Especially, production and storage of hydrogen has very important place on energy researchers [[25], [26], [27]] mentioned the different hydrogen production sources, systems and hydrogen storage options. Also; economic, environmental, social, and technical performance and reliability of the selected options are compared in that study. Additionally, sustainability and infrastructure systematic were deeply analyzed by Refs. [28,29,39].
On the other hand, road transportation vehicle manufacturers generated and produced electric assisted hybrid vehicles for serving the green friendly environment and boosting the performance of vehicles. The importance of using electric motors (EM) in vehicles can be noticed besides on the EM’s efficiencies. More detailed info’s about Hybrid and pure electric vehicle can be reachable from author previous studies [5,6] and also [7,8].
Engineers and researchers, who want to gain more energy potential with H2, opened the season of Fuel Cell Electric Vehicle (FCEV). Fuel Cell (FC), that is an electrochemical device, aimed to converting the chemical energy, from mixing the fuel (especially H2 in road transportation) and oxygen, to electric energy. Mainly, there are six well-known FC types widely used in various applications. FC’s will play an important role on “hydrogen economy” and energy sector. Although there are some demerits in FC applications; they will be pass through in near further with the generation on technology and more preferable costs. Authors kindly suggested their previous study [9] to readers. In Ref. [9]; FCs working principles, their brief history, importance for engineering applications, advantages and disadvantages, FCEV’s overview, technical parameters, costs and theirs situations in sector, refueling stations and next quarter century vision were given detailed.
FCEVs can be admissible for the next steps of electric vehicles. The trends on electric vehicles have performed fruitful screens and it seems they will suit their place in automotive sector. But there are three important barriers on electric vehicles statement. The first one is range of vehicle which directly related with battery capability. According to Energy Department of US [10], Tesla Model S’s range is 539 km per one charge. Conversely, Hyundai’s Nexo offers [11] 666 km per one fueling. When it comes charging time and refueling time; EV needed minimum 6 h (empty to full) [12], but FCEV refueling time is only 3–5 min [13]. The second barrier is come up about environmental envelop. The third one is the maintenance costs and prices of these vehicles. The Society of Motor Manufacturers and Traders report [13], a critical compared information is reflected from Prof. Heywood (MIT), that in 2030, EVs mass production costs will be three times expensive related to FCEVs mass production cost.
Hybridization is a unique chance to deliver the multiple energy sources in any vehicle. Basically, the main advantages of hybrid vehicles are minimizing the emissions and fuel/energy consumptions and improving the performance. For that reason, electric vehicles which driven by electric motors from battery power, surpasses the automotive industry. As it mentioned before, EVs range scale is limited. To upgrade this scale, practitioners added to sole system with traction battery. This type of hybridization is very crucial for determining the energy distribution and performance of vehicle.
In this simulation study; an energy distribution comparison is carried out between FCEV and fuel cell hybrid electric vehicle (FCHEV). Hybridization of FCEV is handled by equipped a traction battery (15 kW). Vehicles simulated and modeled with AVL Cruise program and WLTP (Worldwide Harmonized Light Vehicle Test Procedure) driving cycle is selected for analyses. Energy input/output results given detailed and figured out as sankey diagram template.
Section snippets
Methodology
All engineering applicators have frequently using simulation programs that minimize the time and cost procedure. Before prototyping and manufacturing, simulation and determining process is relieve of producers from unnecessary costs. The two critical start points of simulation procedures are; input variables of analyses and carefully selection of program.
In this study, this subsection is divided into two parts as methodology and simulative design. In methodology part, AVL Cruise program tool
Results and discussion
This section is divided into two parts. First is reserved for FCEV and FCHEVs electric and hydrogen consumptions results in terms of comparative analyses in WLTP driving cycle. Second one is consisted the energy distribution analyses that including the important points of WLTP driving cycle’s instantaneous energy input/output values.
Conclusions
Automotive sector tended to find out the optimum vehicle propulsion system for passengers. It has to be more economical, greener, powerful and energetic. One of the best candidates for this optimization is FCEV that they have rising their popularity day by day. The main purpose of this study is to increase the energy efficiency to the most optimized values and to decrease the hydrogen fuel consumption of the fuel cell electric vehicle on the fuel cell.
For that reason, in this study, FCHEV and
Acknowledgement
This study was conducted with AVL CRUISE. Authors acknowledge to AVL-AST, Graz, Austria to provide these simulation tools under university partnership program.
References (44)
- et al.
Experimental investigation of using 30HCNG fuel mixture on a non-modified diesel engine operated with various diesel replacement rates
Int J Hydrogen Energy
(2016) - et al.
Effect of using Hydroxy – CNG fuel mixtures in a non-modified diesel engine by substitution of diesel fuel
Int J Hydrogen Energy
(2016) Alternative fuelled hybrid electric vehicle (AF-HEV) with hydrogen enriched internal combustion engine
Int J Hydrogen Energy
(2019)Simulation of diesel hybrid electric vehicle containing hydrogen enriched CI engine
Int J Hydrogen Energy
(2019)- et al.
Comparative life cycle assessment of hydrogen, methanol and electric vehicles from well to wheel
Int J Hydrogen Energy
(2017) - et al.
Overview of the next quarter century vision of hydrogen fuel cell electric vehicles
Int J Hydrogen Energy
(2019) - et al.
Optimization and integration of hybrid renewable energy hydrogen fuel cell energy systems–A critical review
Appl Energy
(2017) - et al.
A comprehensive review on hybrid power system for PEMFC-HEV: issues and strategies
Energy Convers Manag
(2018) - et al.
Real-time strategies to optimize the fueling of the fuel cell hybrid power source: a review of issues, challenges and a new approach
Renew Sustain Energy Rev
(2018) - et al.
Improving fuel economy and performance of a fuel-cell hybrid electric vehicle (fuel-cell, battery, and ultra-capacitor) using optimized energy management strategy
Energy Convers Manag
(2018)