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Issues such as climate change and ever-increasing global warming have obliged governments and world authorities to comply with stringent regulations on the control of greenhouse gas(GHG) emissions in internal combustion engines (ICEs). Carbon dioxide (CO2), the most produced GHG, has been the major concern of climate change in recent years. To reduce carbon emissions, fuels with lower carbon content, such as alcohol fuels, or fuels with no carbon content, like hydrogen and ammonia, should be taken into consideration to be replaced by fossil fuels in internal combustion engines.

The charging and discharging process of batteries generates a significant amount of heat, which can adversely affect their lifespan and safety. This study aims to enhance the performance of a lithium-ion battery (LIB) pack with a high discharge rate (5C) by proposing a combined battery thermal management system (BTMS) consisting of improved phase change materials (paraffin/aluminum composite) and forced-air convection. Battery thermal performance is simulated using computational fluid dynamics (CFD) to study the effects of heat transfer and flow parameters. To evaluate the impact of essential parameters on the thermal performance of the battery module, temperature uniformity and maximum temperature in the cells are evaluated. For the proposed cooling system, an ambient temperature of 24.5 °C and the application of a 3 mm thick paraffin/aluminum composite showed the best cooling effect. In addition, a 2 m/s inlet velocity with 25 mm cell spacing provided the best cooling performance, thus reducing the maximum temperature. The paraffin can effectively manage thermal parameters maintaining battery temperature stability and uniformity. Simulation results demonstrated that the proposed cooling system combined with forced-air convection, paraffin, and metal foam effectively reduced the maximum temperature and temperature difference in the battery by 308 K and 2.0 K, respectively.

The battery thermal management system (BTMS) for lithium-ion batteries can provide proper operation conditions by implementing metal cold plates containing channels on both sides of the battery cell, making it a more effective cooling system. The efficient design of channels can improve thermal performance without any excessive energy consumption. In addition, utilizing phase change material (PCM) as a passive cooling system enhances BTMS performance, which led to a hybrid cooling system. In this study, a novel design of a microchannel distribution path where each microchannel branched into two channels 40 mm before the outlet port to increase thermal contact between the battery cell and microchannels is proposed. In addition, a hybrid cooling system integrated with PCM in the critical zone of the battery cell is designed. Numerical investigation was performed under a 5C discharge rate, three environmental conditions, and a specific range of inlet velocity (0.1 m/s to 1 m/s). Results revealed that a branched microchannel can effectively improve thermal contact between the battery cell and microchannel in a hot area of the battery cell around the outlet port of channels. The designed cooling system reduces the maximum temperature of the battery cell by 2.43 °C, while temperature difference reduces by 5.22 °C compared to the straight microchannel. Furthermore, adding PCM led to more uniform temperature distribution inside battery cell without extra energy consumption.

Over the past few years, fuel prices have increased dramatically, and emissions regulations have become stricter in maritime applications. In order to take these factors into consideration, improvements in fuel consumption have become a mandatory factor and a main task of research and development departments in this area. Internal combustion engines (ICEs) can exploit only about 15–40% of chemical energy to produce work effectively, while most of the fuel energy is wasted through exhaust gases and coolant. Although there is a significant amount of wasted energy in thermal processes, the quality of that energy is low owing to its low temperature and provides limited potential for power generation consequently. Waste heat recovery (WHR) systems take advantage of the available waste heat for producing power by utilizing heat energy lost to the surroundings at no additional fuel costs. Among all available waste heat sources in the engine, exhaust gas is the most potent candidate for WHR due to its high level of exergy. Regarding WHR technologies, the well-known Rankine cycles are considered the most promising candidate for improving ICE thermal efficiency. This study is carried out for a six-cylinder marine diesel engine model operating with a WHR organic Rankine cycle (ORC) model that utilizes engine exhaust energy as input. Using expander inlet conditions in the ORC model, preliminary turbine design characteristics are calculated. For this mean-line model, a MATLAB code has been developed. In off-design expander analysis, performance maps are created for different speed and pressure ratios. Results are produced by integrating the polynomial correlations between all of these parameters into the ORC model. ORC efficiency varies in design and off-design conditions which are due to changes in expander input conditions and, consequently, net power output. In this study, ORC efficiency varies from a minimum of 6% to a maximum of 12.7%. ORC efficiency performance is

This study aimed to investigate the potential of supercritical carbon dioxide (sCO2), organic Rankine cycle (ORC), and thermoelectric generator (TEG) systems for application in automotive exhaust waste heat recovery (WHR) applications. More specifically, this paper focuses on heavy-duty diesel engines applications such as marine, trucks, and locomotives. The results of the simulations show that sCO2 systems are capable of recovering the highest amount of power from exhaust gases, followed by ORC systems. The sCO2 system recovered 19.5 kW at the point of maximum brake power and 10.1 kW at the point of maximum torque. Similarly, the ORC system recovered 14.7 kW at the point of maximum brake power and 7.9 kW at the point of maximum torque. Furthermore, at a point of low power and torque, the sCO2 system recovered 4.2 kW of power and the ORC system recovered 3.3 kW. The TEG system produced significantly less power (533 W at maximum brake power, 126 W at maximum torque, and 7 W at low power and torque) at all three points of interest due to the low system efficiency in comparison to sCO2 and ORC systems. From the results, it can be concluded that sCO2 and ORC systems have the biggest potential impact in exhaust WHR applications provided the availability of heat and that their level of complexity does not become prohibitive.

Hydrogen, as a suitable and clean energy carrier, has been long considered a primary fuel or in combination with other conventional fuels such as gasoline and diesel. Since the density of hydrogen is very low, in port fuel-injection configuration, the engine’s volumetric efficiency reduces due to the replacement of hydrogen by intake air. Therefore, hydrogen direct in-cylinder injection (injection after the intake valve closes) can be a suitable solution for hydrogen utilization in spark ignition (SI) engines. In this study, the effects of hydrogen direct injection with different hydrogen energy shares (HES) on the performance and emissions characteristics of a gasoline port-injection SI engine are investigated based on reactive computational fluid dynamics. Three different injection timings of hydrogen together with five different HES are applied at low and full load on a hydrogen–gasoline dual-fuel SI engine. The results show that retarded hydrogen injection timing increases the concentration of hydrogen near the spark plug, resulting in areas with higher average temperatures, which led to NOX emission deterioration at −120 Crank angle degree After Top Dead Center (CAD aTDC) start of injection (SOI) compared to the other modes. At −120 CAD aTDC SOI for 50% HES, the amount of NOX was 26% higher than −140 CAD aTDC SOI. In the meanwhile, an advanced hydrogen injection timing formed a homogeneous mixture of hydrogen, which decreased the HC and soot concentration, so that −140 CAD aTDC SOI implied the lowest amount of HC and soot. Moreover, with the increase in the amount of HES, the concentrations of CO, CO₂ and soot were reduced. Having the HES by 50% at −140 CAD aTDC SOI, the concentrations of particulate matter (PM), CO and CO₂ were reduced by 96.3%, 90% and 46%, respectively. However, due to more complete combustion and an elevated combustion average temperature, the amount of NOX emission increased drastically.

Low-temperature combustion (LTC) engines are able toreduce nitrogen oxides (NOx) and particulate matter (PM) emissions, simultaneously. LTC engines suffer from higher amounts of unburned hydrocarbon (uHC) and carbon monoxide (CO) emissions, particularly in low-load operating conditions of the engine. The existence of oxygen molecules in the alcohol fuels not only results in more combustion completeness but also leads to lower CO and uHC emissions.

The unique properties of natural gas (NG), including high availability and lower cost compared with other fossil fuels, make it attractive in internal combustion engine (ICE) application. NG is composed mainly of methane and has greater knock resistance than gasoline, enabling higher compression ratios (CR). In contrast with the distinctive advantages, the NG fueled engines suffer from lower power and torque outputs. To address the subject, this study proposes an approach employing NG direct injection (NGDI) strategy (with higher volumetric efficiency unlike port injection), enabling a higher CR irrespective of knock limit. This work applies reactive computational fluid dynamics (CFD) to investigate spark ignited co-combustion of direct-injected NG with port-admitted gasoline. The results are validated against experimental data. In all simulated cases, the equivalence ratio (i.e., ∅ = 1) and the total input energy are kept constant. Engine performance is evaluated for three CRs (10.5, 11.5, and 12.5:1), five proportion of CNG (RCNG) and at part- and full-load conditions at an engine speed of 1500 rpm. Results indicated that while running RCNG = 100 % with a CR of 10.5:1, carbon monoxide (CO) and carbon dioxide (CO₂) emissions were decreased by 29.3 % and 23.5 % respectively, compared to RCNG = 0 %. The corresponding emission reduction at CR = 11.5:1 was 27.1 % and 24 %; at CR = 12.5:1 they were 29.6 % and 23.5 % respectively. At each CR, the knock intensity at full load fell significantly as the percentage of NG increased. At a CR of 12.5:1, ringing intensity (RI) at full load decreased by 88.6 % when using RCNG = 100 %, instead of RCNG = 0 %. Under the same conditions, RCNG = 25 % cut RI by 56 %.

The transportation sector is generally thought to be contributing up to 25% of all greenhouse gases (GHG) emissions globally. Hence, reducing the usage of fossil fuels by the introduction of electrified powertrain technologies such as hybrid electric vehicle (HEV), battery electric vehicle (BEV) and Fuel Cell Electric Vehicle (FCEV) is perceived as a way towards a more sustainable future. With a seemingly more significant shift towards BEV development and roll-out, the research and development of BEV technologies has taken on increasing importance in improving BEV performance and ensuring its competitiveness. Numerical simulation, using MATLAB, is performed as a tool to investigate and to improve the overall performance of BEVs. This study provides an overview of the possible technology outcome and market consequences for future compact BEVs along with HEVs, FCEVs and internal combustion engine vehicles (ICEV). The techno-economics of BEVs, market projection and cost analysis up to 2050 are investigated, as are important BEV characteristics alongside those of other types of vehicles. Well-to-wheel analysis of BEVs is also studied and compared with HEV, FCEV and ICE.

Utilizing Solar Chimney Power Plants (SCPPs) for manufacturing clean and environment-friendly energy has drawn a lot of attention in recent years and has (over the passing decades) become one of the most promising solutions in the solar energy field. Low efficiency, construction difficulties and other required improvements have encouraged researchers to work on this system. Many researchers put their efforts into proposing an optimized configuration for the main components, whereas others have proposed innovative ideas and add-on accessories to improve solar chimney power plants from an efficiency or construction viewpoint. This paper provides a comprehensive review of the past few decades and includes analyses of the theoretical, experimental and numerical studies conducted focused on optimizing the main characters of the system, such as the chimney, collector and Power Conversion Unit (PCU) together with other recently suggested innovative ideas and alternative technologies to improve solar chimney power plants efficiency. Concurrently, other researchers focused on hybrid solar chimney power plants to produce the desired by-product such as distilled water and so make SCPPs more practical.