scholarly journals Optimal Control for a Hydraulic Recuperation System Using Endoreversible Thermodynamics

2021 ◽  
Vol 11 (11) ◽  
pp. 5001
Author(s):  
Robin Masser ◽  
Karl Heinz Hoffmann

Energy savings in the traffic sector are of considerable importance for economic and environmental considerations. Recuperation of mechanical energy in commercial vehicles can contribute to this goal. One promising technology rests on hydraulic systems, in particular for trucks which use such system also for other purposes such as lifting cargo or operating a crane. In this work the potential for energy savings is analyzed for commercial vehicles with tipper bodies, as these already have a hydraulic onboard system. The recuperation system is modeled based on endoreversible thermodynamics, thus providing a framework in which realistic driving data can be incorporated. We further used dissipative engine setups for modeling both the hydraulic and combustion engine of the hybrid drive train in order to include realistic efficiency maps. As a result, reduction in fuel consumption of up to 26% as compared to a simple baseline recuperation strategy can be achieved with an optimized recuperation control.

Author(s):  
J-P Gao ◽  
G-M G Zhu ◽  
E G Strangas ◽  
F-C Sun

Improvements in hybrid electric vehicle fuel economy with reduced emissions strongly depend on their supervisory control strategy. In order to develop an efficient real-time supervisory control strategy for a series hybrid electric bus, the proposed equivalent fuel consumption optimal control strategy is compared with two popular strategies, thermostat and power follower, using backward simulations in ADVISOR. For given driving cycles, global optimal solutions were also obtained using dynamic programming to provide an optimization target for comparison purposes. Comparison simulations showed that the thermostat control strategy optimizes the operation of the internal combustion engine and the power follower control strategy minimizes the battery charging and discharging operations which, hence, reduces battery power loss and extends the battery life. The equivalent fuel consumption optimal control strategy proposed in this paper provides an overall system optimization between the internal combustion engine and battery efficiencies, leading to the best fuel economy.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yongxiang Li ◽  
Chujin Hu ◽  
Zhenwen Chen ◽  
Chunhui Wang ◽  
Jing Li ◽  
...  

AbstractEnergy savings and environmental protection are the only way for the sustainable development of the automotive industry. The poor shifting performance of automobile transmission may reduce the driver's driving pleasure and make the driver feel tired. In addition, improper shifting would also increase fuel consumption. Therefore, in view of the importance of improving the shift performance of vehicle transmission, GSA testing technology was employed for the existing shift quality problems of commercial vehicles to continuously realize high shifting efficiency and low fuel consumption. Through the establishment of subjective and objective evaluation criteria of the experimentally determined shift performance of commercial vehicles, a reliable theoretical basis is provided for product optimization design and shift performance evaluation. As a result, the shift control strategy and optimization matching measures are formulated to ensure that the power, smoothness and transmission of the whole vehicle system meet the technical requirements and finally achieve a rapid and stable gearshift. Thus, this work unveils the high potential of improving the shift performance and quality of the whole vehicle and is expected to have an impact on reducing fuel consumption and emissions in the relevant automotive industry, contributing to the establishment of a more sustainable society.


2018 ◽  
Vol 9 (1) ◽  
pp. 12 ◽  
Author(s):  
Stefan Geng ◽  
Andreas Meier ◽  
Thomas Schulte

Plug-in hybrid electric vehicles are developed in order to reduce the fuel consumption and the emission of carbon dioxide. Besides the series, parallel and power split configurations are commonly used for conventional hybrid electric vehicles, and multimode transmissions are used for plug-in hybrid electric vehicles, which are able to switch between different modes like parallel or series operation of the combustion engine and electric motor. Several concepts have already been discussed and presented. These concepts comprise novel structures and multi-speed operation for the combustion engine and the electric motor, respectively. For improving the fuel and energy consumption, model-based optimizations of multimode transmissions are performed. In the first step of the optimization, the optimal number of gears and transmission ratios, as well as the corresponding fuel and energy savings, are estimated. Based on these results, a new multimode transmission concept with two-speed transmissions for the combustion engine and the electric motor has been developed. The knowledge of the concrete concept enables the further optimizations of the transmission ratios and the transmission control. In order to prove the benefit of the new and optimized transmission concept, powertrain simulations have been carried out. The new powertrain concept is compared to a powertrain concept with single-speed transmissions for the internal combustion engine (ICE) and electric motor operation. The new transmission concept enables a significant improvement of the fuel consumption.


2013 ◽  
Vol 597 ◽  
pp. 185-192 ◽  
Author(s):  
Jacek Kropiwnicki ◽  
Zbigniew Kneba

Operating fuel consumption increases significantly when the vehicle stops frequently while driving or when the engine is idling during braking. In such cases, the internal combustion engine consumes the fuel but the mechanical energy is not used by the drive system. The amount of fuel that is consumed in this time by the engine can potentially be saved if the car is equipped with a Stop-Start system. Start-Stop system automatically shuts down and restarts the internal combustion engine due to strategy used by controller reducing this way toxic compounds emissions in exhaust gasses and the fuel consumption, which is directly connected to carbon dioxide (CO2) emissions. The paper presents an analysis of the potential reduction in CO2 emissions for selected vehicles with Start-Stop system during operation in selected urban agglomeration using different strategies to control this system. The study was carried out using numerical models of propulsion systems. The results were compared with the statistical data derived from regular use of vehicles equipped with such a system.


2021 ◽  
Vol 13 (13) ◽  
pp. 7348
Author(s):  
Ahmad Zuhairi Muzakir ◽  
Eng Hwa Yap ◽  
Teuku Meurah Indra Mahlia

Final energy use in Malaysia by the transport sector accounts for a consistent share of around 40% and even more in some years within the past two decades. Amongst all modes of transport, land transport dominates and within land transport, private travels are thought to be the biggest contributor. Personal mobility is dominated by the use of conventional internal-combustion-engine-powered vehicles (ICE), with the ownership trend of private cars has not shown any signs of tapering-off. Fuel consumption by private cars is currently not governed by a national policy on fuel economy standards. This is in contrast against not only the many developed economies, but even amongst some of the ASEAN neighbouring countries. The lack of fuel economy standards has resulted in the loss of potentially tremendous savings in fuel consumption and emission mitigation. This study analysed the increase in private vehicle stock to date, the natural fuel economy improvements brought by technology in a business as usual (BAU) situation, and the additional potential energy savings as well as emissions reduction in the ideal case of mandatory fuel economy standards for motor vehicles, specifically cars in Malaysia. The model uses the latest available data, relevant and most current parameters for the simulation and projection of the future scenario. It is found that the application of the fuel economy standards policy for cars in Malaysia is long overdue and that the country could benefit from the immediate implementation of fuel economy standards.


2015 ◽  
Vol 160 (1) ◽  
pp. 11-25
Author(s):  
Wojciech CIEŚLIK ◽  
Ireneusz PIELECHA ◽  
Andrzej SZAŁEK

An increased interest in hybrid drive systems allowing reduction of fuel consumption and emissions of harmful substances into the atmosphere, as well as their partial use as zero–emission vehicles promotes the development of these types of drive systems. The market analysis indicates an increased sale of hybrid drives in vehicles, and this means that actions taken towards of reduction of fuel consumption are still valid. The aim of this article is to indicate the indexes of performance of combustion engines in hybrid vehicles during a part of the type-approval driving test. The article analyses Toyota hybrid vehicles with particular attention paid to the parameters of the hybrid drive system and the influence of the charge level of battery on the share of the combustion engine operation in the total time of the vehicle operation. The analysis was carried out for vehicles equipped with the Toyota Hybrid Synergy Drive system working with different types of high voltage battery.


Author(s):  
Folker Renken

Vehicles with hybrid drive systems are characterized by their driving dynamics, their energy efficiency and their environment-friendliness especially. Dependent on the electrical power and the drive train structure these hybrid drives are grouped into different classes. Designations such as micro-hybrid, mild- hybrid, full-hybrid, serial-hybrid, serial/parallel-hybrid or power-split-hybrid reflect the large variance of these different drive train possibilities. In hybrid drive systems electronically controlled converters take an important role. With such a converter also the energy exchange between electrical power system and electrical machine is regulated. The reduction of the vehicle fuel consumption here is of special interest. Today's hybrid vehicles use for the control mainly information from the present driving conditions, taking into account the actual electrical power system-charge as well as the power demand of the driver. With such a control already considerable fuel reductions are reached. But additionally superimposed control and information systems promise substantial potential for more fuel reduction. With these systems an outstanding energy-saving and anticipatory way of driving could be realized. The aim is to find the best operating point in each case for the combustion engine and to adapt the charge state of the electrical power system to the respective driving situation.


Author(s):  
Charbel R Ghanem ◽  
Elio N Gereige ◽  
Wissam S Bou Nader ◽  
Charbel J Mansour

There have been many studies conducted to replace the conventional internal combustion engine (ICE) with a more efficient engine, due to increasing regulations over vehicles’ emissions. Throughout the years, several external combustion engines were considered as alternatives to these traditional ICEs for their intrinsic benefits, among which are Stirling machines. These were formerly utilized in conventional powertrains; however, they were not implemented in hybrid vehicles. The purpose of this study is to investigate the possibility of implementing a Stirling engine in a series hybrid electric vehicle (SHEV) to substitute the ICE. Exergy analysis was conducted on a mathematical model, which was developed based on a real simple Stirling, to pinpoint the room for improvements. Then, based on this analysis, other configurations were retrieved to reduce exergy losses. Consequently, a Stirling-SHEV was modeled, to be integrated as auxiliary power unit (APU). Hereafter, through an exergo-technological detailed selection, the best configuration was found to be the Regenerative Reheat two stages serial Stirling (RRe-n2-S), offering the best efficiency and power combination. Then, this configuration was compared with the Regenerative Stirling (R-S) and the ICE in terms of fuel consumption, in the developed SHEV on the WLTC. This was performed using an Energy Management Strategy (EMS) consisting of a bi-level optimization technique, combining the Non-dominated Sorting Genetic Algorithm (NSGA) with the Dynamic Programming (DP). This arrangement is used to diminish the fuel consumption, while considering the reduction of the APU’s ON/OFF switching times, avoiding technical issues. Results prioritized the RRe-n2-S presenting 12.1% fuel savings compared to the ICE and 14.1% savings compared to the R-S.


2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Markus Kiesenhofer

AbstractHybridization of the drive train in commercial vehicles is a key solution toward meeting the strict future requirements to reduce carbon dioxide emissions within the European Union. In order to decrease fleet consumption a large number of different hybrid systems are already available in series in the passenger car sector. Due to the cheap and powerful 48 volt hybrid components and the lower hazard potential compared to high voltage, future commercial vehicles could also benefit from the 48V technology and contribute to lower fleet fuel consumption. Therefore, a complete 48V mild hybrid system was built on the diesel engine test bench as part of a research project. This paper highlights the utilization of a powerful 48V-motor to propel the coolant pump on a diesel engine of the 13-L commercial vehicle class. Three different drive variants of the coolant pump were implemented and measured on the diesel engine test bench. MATLAB®/Simulink®-simulations were conducted to assess the possible fuel savings in three different driving cycles. This paper provides a summary and interpretation of the measurement and simulation results. The simulation studies predict a decrease of fuel consumption of up to 0.94%. Furthermore, the additional advantages of electrified coolant pumps based on 48V are discussed.


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