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The waste heat recovery (WHR) system appears to lower overall fuel consumption of the engine by producing additional power and curtailing greenhouse emissions per unit of power produced. In this project, a 25.5 kW diesel engine is used and simulated, which has an exhaust temperature of about 470°C. During optimization of the heat exchangers, the overall weight of the heat exchangers is kept low to reduce the final cost. Additionally, the overall pressure drops across the superheater, boiler, and economiser are kept at around 200 kPa to expel the exhaust gas into the atmosphere easily. To accomplish high heat-transfer across the heat exchangers, the pinch temperature of the hot and cold fluids is kept above 20°C. In this project, under the design constraints and available heat at the exhaust gases, the WHR system has enhanced the power and reduced the break specific fuel consumption by around 6.2% and 5.8%, respectively at 40 bar pressure.

Because of the negative impacts of pollutions on us and our surroundings, it is important to measure the magnitude of emissions in metropolitan areas where the emission concentrations are highest. The Mesoscale approach was used for probabilistic emission inventory. The traffic volume data for each road link were required and collected from the Victoria state road traffic authority for further calculation for different Euro standards in different vehicle categories. The pollutants studied in this paper are nitrogen oxides (NOX), carbon monoxide (CO), and particulate matter (PM), as transportation-induced emissions constitute the principal source of city pollution. This paper examined the deterministic modelling and stochastic modelling approaches for estimating on-road emissions. The Monte Carlo simulation approach was applied for stochastic modelling.

In this study, a 1.1 MW diesel-gen-set is used to design a Waste Heat Recovery (WHR) system to generate additional power using Rankine cycle (RC). A computer code is written in commercial Engineering Equation Solver (EES) software to solve equations of overall energy and mass balance, heat transfer, evaporation, condensation, frictional and heat losses for heat exchangers, turbine, pumps, cooling tower and connecting pipes connecting different components. After initial design of the WHR system, manufacturers are contacted to find out the availability of parts, and then, accordingly the design is changed. There are several heat exchangers required to heat the water from liquid to superheated steam and then, it is passed to the turbine. Then, after the expansion in the turbine, it is passed to the condenser to condense the steam to water. Optimization is done on the heat exchangers, focusing on the tube length and diameter.

Fast consumption of fossil fuels is demanding researchers to find few potential alternative fuels that meet sustainable energy demand in the near future with least environmental impact. Future energy system needs to be cost-efficient, renewable, and safe to handle. Biodiesel is expected to be the future energy source that meets all the environmental norms. The use of biodiesel in Internal Combustion (IC) engines represents an alternative clean energy source compared to hydrocarbon fuels that generate emissions such as carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOX), Sulfur Oxides (SO) and particulate matters (PM). This paper describes the importance of Palm Oil Diesel (POD) as an alternative fuel source for diesel engines. Simulations are carried out with ANSYS FORTE software with POD. The engine chosen is a 26-kW diesel-gen-set. The engine geometry is drawn in SOLIDWORKS using dimensions of the actual diesel engine.

Internal combustion (IC) engine exhaust system can influence the engine’s performance in a significant way. This paper shows that a variable exhaust manifold runner length can improve the engine performance in terms of its output torque by over 10% especially at lower engine speed. Similarly, other exhaust systems such as valve timing and valve lift can improve the performance of the engine in different magnitudes. But when smaller improvements are clubbed together, a significant improvement can be achieved. This paper researches first the exhaust runner length on the engine’s performance. Then, the exhaust valve timing is adjusted to further improve the engine torque produced for the exhaust runner lengths analyzed. Study of a combined effect showed that the runner length requirement shifts slightly as the valve timing is changed.

Design of the intake system of an internal combustion (IC) engine is one of the critical parameters to improve the performance of an engine. Induction pressure waves (compression and rarefaction waves) are created in the intake runner due to valve operations. If the intake runner is tuned correctly, a compression wave can boost the intake air flow improving the volumetric efficiency which increases the torque and power of the engine. In this research, the intake runner diameter and valve timing were varied individually, after which both were varied together to achieve optimum volumetric efficiency. A single-cylinder, four-stroke spark-ignited 510 cc naturally aspirated engine was used for the analysis. Simulations were carried out using engine simulation software Ricardo Wave to find the effect of intake runner diameter and timing on the engine performance.

This paper focuses on waste heat recovery (WHR) system, which is an efficient technology to reduce fuel and vehicle carbon dioxide (CO2) emissions per kW of power produced. Wide variations of power of a vehicle make it difficult to design a WHR system which can operate optimally at all powers. The exhaust temperature from the engine is critical to design a WHR system. Higher the temperature higher will be the gain from the WHR system. However, as power drops the exhaust temperature drops which makes the WHR system perform poorly at lower powers. In this research, a small diesel truck engine was used to design a WHR system to produce additional power using a Rankine cycle (RC). The WHR system was designed at the rated power and speed of 42.8 kW and 2600 rpm, respectively. At this design point, around 15% additional power improvement was achieved resulting around 13% break specific fuel consumption reduction.

In this paper, a waste heat recovery (WHR) system is designed to recover heat from the exhaust of a diesel-gen-set having an engine of 26.57 kW. The Rankine Cycle (RC) and the Organic Rankine Cycle (ORC) are used to produce additional power using water, R113, R124 and R245fa as the working fluids. Water as the working fluid gives the best improvement of 13.8% power improvement with 12.2% bsfc reduction, but fails to produce any power at the lowest operating power of 5.8 kW due to lower exhaust temperature and higher boiling point of water. This is when the WHR system is designed at the rated power of 26.57 kW. Designing at lower power of 20.0 kW improves the enhancements at this and lower powers but reduces the improvement at the rated power of 26.57 kW. This design again fails to produce any power at the lowest power.

Waste Heat Recovery System (WHRS) is used to extract heat from the exhaust gas from internal combustion (IC) engines to produce additional power with increase in overall efficiency of the engine. Amongst various WHRS, this paper focuses on WHRS using Rankine Cycle (RC) and Organic Rankine Cycle (ORC). A 100 kVA (80 kW engine) diesel generator was used for this research. Water, R245fa, and R134a were used as the working fluids for the cycle. To assess the performance of WHRS, the system was designed for 80 kW, 70 kW and 60 kW loads and then, for each designed load the WHRS was run for other loads and then compared. Assessment provide simulation results of RC and ORC using Engineering Equation Solver (EES) software. It was found that using water as the working fluid around 20% additional power was achieved. But it limited the working range of the system making it unsuitable for lower loads of 10 and 20 kW for this generator.

To comply with the new Corporate Average Fuel Economy (CAFE) standards, automakers are expected to increase the average fuel economy of their vehicles to 54.5 miles per gallon from the current 24.8 miles per gallon by 2025. This research aims at proposing a feasible solution to narrow down the gap between the current and expected fuel economy of the vehicles, yet maintaining the engine’s original performance. A standard model of the KTM 510 cc single cylinder, fuel injected, internal combustion engine (IC) engine is modelled and simulated in Ricardo Wave software package to map the stock engine performance and specific fuel consumption at wide open throttle (WOT). The baseline simulation model is validated against the experimental readings with 98% accuracy.

In general, diesel engines have an efficiency of about 35% and hence, a considerable amount of energy is expelled to the ambient air. In water-cooled engines, about 25%, 33% and 7% of the input energy are wasted in the coolant, exhaust gas, and friction, respectively. The heat from the exhaust gas of diesel engines can be an important heat source to provide additional power and improve overall engine efficiency. Studies related to the application of recoverable heat to produce additional power in medium capacity diesel engines (< 100 kW) using separate Rankine cycle are scarce. To recover heat from the exhaust of the engine, an efficient heat exchanger is necessary. For this type of application, the heat exchangers are needed to be designed in such a way that it can handle the heat load with reasonable size, weight and pressure drop. This paper describes the study of a diesel generator-set attached with an exhaust heat recovery system.

Diesel engine can be run with biodiesel which has the potential to supplement the receding supply of crude oil. As biodiesel possess similar physiochemical properties to diesel, most diesel engines can run with biodiesel with minimum modifications. However, the viscosity of biodiesel is higher, and the calorific value is lower than diesel. Therefore, when biodiesel is used in diesel engines, it is usually blended with diesel at different proportions. Use of 100% biodiesel in diesel engines shows inferior performance of having lower power and torque. Improving in-cylinder airflow characteristic to break down higher viscous biodiesel and to improve air-fuel mixing are the aims of this research. Therefore, guide vanes in the intake runner were used in this research to improve the performance of diesel engine run with biodiesel.

The heat from the exhaust gas of diesel engines can be an important heat source to provide additional power using a separate Rankine Cycle (RC) or an Organic Rankine Cycle (ORC). Water is the best working fluid for this type of applications in terms of efficiency of the RC system, availability and environmental friendliness. However, for small engines and also at part load operations, the exhaust gas temperature is not sufficient enough to heat the steam to be in superheated zone, which after expansion in the turbine needs to be in superheated zone. Ammonia was found to be an alternate working fluid for these types of applications which can run at low exhaust temperatures. Computer simulation was carried out with an optimized heat exchanger to estimate additional power with water and ammonia as the working fluids. ANSYS 14.0 CFX software was used for the simulation.

The performance of a compression ignition (CI) engine run with alternative fuel is inferior to when it is run with petro-diesel resulting in lower power, higher fuel consumption and higher carbon deposits. This is due to the poorer properties of the alternative fuel for the CI engine compared to petro-diesel, for instance, higher viscosity. Due to this factor, this research has grouped these fuels as higher viscous fuels (HVFs). In order to solve or reduce the problem of higher viscosity, this paper presents research that has sought to improve the in-cylinder airflow characteristics by using a guide vane so that the evaporation, diffusion, mixing and combustion processes can be stimulated eventually improving or at least reducing the problem. The in-cylinder airflow was studied using ANSYS-CFX with the help of SolidWorks. Firstly, the validated base model replicated from the generator of a CI engine was prepared.

Exhaust gases from diesel engines can be an adequate source of energy to run a bottoming Rankine cycle to increase the overall efficiency of the engine as it contains a significant portion of input energy. In this research, an automotive diesel engine was tested to estimate the available energy in the exhaust gas. Shell and tube heat exchangers were used to extract the heat from the exhaust gas and the performance of the two shell and tube heat exchangers were investigated with parallel and counter flow arrangements using water as the working fluid. The results obtained were below satisfactory as these heat exchangers were purchased from the marketplace and not optimized for this particular application. Thus attempts were made to optimize the design of the heat exchanger by computer simulation using the available experimental data.

Due to depletion of crude oil and exhaust emissions associated with internal combustion engine, biodiesel, neat vegetable oil and waste cooking oil are identified as potential alternative fuels to run on diesel engines. However, the viscosities of these fuels are higher than diesel and can be grouped as higher viscous fuel (HVF). Currently, diesel engines fuelled by HVF experience problems of reduced power and torque besides increased fuel consumption and in-cylinder carbon deposit. These are mainly due to poor combustion as HVF is less prone to evaporate and mix with air. To reduce these problems, a technique to improve the air-fuel mixing in diesel engine fuelled by HVF using Guide Vane Swirl and Tumble Device (GVSTD) is presented in this paper. Validated simulation model for a diesel engine was developed using Solidworks and ANSYS-CFX before 12 GVSTD models were imposed in front of the intake runner with the vane twist angle varied from 3° to 60°.