As global water scarcity intensifies, this study proposes a solution by utilizing surplus heat from a diesel generator set to enhance freshwater production through a waste heat recovery (WHR) system. The system is simulated and optimized using Engineering Equation Solver (EES) to improve freshwater production efficiency. Results indicate that the WHR system can produce 13.9 million liters (ML) of freshwater annually, with a payback period of 4.63 years for freshwater alone, confirming strong viability. In addition, the system can generate 160,000 kWh of electricity, which reduces the combined payback period to 2.12 years. Key design constraints include maintaining a minimum exhaust pressure of 100 kPa (absolute) and placing the WHR system along the gen-set’s long side. These requirements demand a compact design with a minimum pinch temperature of 20 K. The system’s main components are aligned with the gen-set, resulting in a total footprint of 60.5 m2 and a system weight of 25 tons, compared with 8.52 m2 and 12.6 tons for the generator.

Approximately one-third of fuel energy in internal combustion engines dissipates as exhaust gas heat, posing a significant obstacle to electricity generation. Interest in recovering this waste heat is growing, and this paper proposes a solution by utilizing surplus heat from a diesel engine to enhance power generation through a Waste Heat Recovery (WHR) system. The main objectives are to improve power generation efficiency by simulating and optimizing the WHR system using Engineering Equation Solver (EES), focusing on maximizing power output and freshwater production while minimizing costs. For a 1.1 MW diesel-gen-set, the system achieves a remarkable net additional power production of 131.0 kW, with an expected payback period of 4.8 years. Additionally, the WHR system can produce 8.56 ML/year of freshwater with a payback period of 4.63 years. Combining additional power and freshwater production reduces the payback period to just 2.0 years. Key parameters such as maintaining a 100 kPa absolute exhaust pressure, an aspect ratio of approximately 3, and a pinch temperature of 20 K provide valuable operational insights. Sensitivity analysis of these parameters enhances understanding of their impact on system performance, guiding future research toward more efficient and sustainable WHR systems.

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. The maximum net power produced is around 1.5 kW at 40 bar steam pressure. All thermodynamic equations have been set up and solved with the help of Engineering Equation Solver (EES) software to meet the manufacturer’s requirements such as the length of heat exchangers, the number of the tubes and rows, and the gap between the tubes, thickness of tubes, and materials. In the last, the cost of all required components is considered. The cost of the entire WHR system is calculated at around $14,220 and the payback period is around 4 years and 5 months.

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. Estimated emissions were calculated using a deterministic approach for various road links, which were 79,000 g/km Carbon Monoxide (CO) for light private vehicles for a particular road link, but when the emissions for the same link were calculated using stochastic modelling, the emission estimated were around 82,000 g/km Carbon Monoxide (CO). This paper also analyzed different scenarios and future scenarios. When a 21% growth (in the year 2030) in vehicle registration is expected, considering the current growth trend, a 17% increase in CO emission is estimated in all vehicle categories. Different scenarios were analyzed assuming 50% of euro 3 vehicles were replaced by euro 5 (by the year 2020), then there would be a 34% reduction in CO emission for the same road link, which is 31,191 g/km less.

The use of renewable biodiesel fuel in diesel engines can reduce the demand for depleting fossil fuels and reduce harmful emissions to the environment. In this research, an engine simulation is conducted using ANSYS Forte software, which allows for visualization of the spray inside the combustion chamber. The results show that biodiesel has higher liquid and vapor penetration lengths, higher droplet mass and diameter, and a longer breakup length. Molecular images of fuel molecules show that the temperature of biodiesel molecules is 141 °C lower than diesel molecules at 709 degree crank angle (°CA). These characteristics result in an extended evaporation time for biodiesel, consequently leading to poorer performance. Additionally, increased penetration length can lead to carbon deposits inside the combustion chamber. Therefore, such inefficiencies of biodiesel spray properties lead to lower combustive performance than diesel. In terms of performance, on average, biodiesel produces 16.9% lower power and 19.9% higher brake specific fuel consumption. On average, the emissions of CO, CO2, and HC of biodiesel are 17.8%, 3.41%, and 23.5% lower and NOx is 14.39% higher than the corresponding values obtained for pure diesel, respectively. In-cylinder combustion analyses show that the peak pressure of biodiesel is 0.5 MPa lower, the peak cycle temperature is 36 °C lower, the ignition delay is 4 °CA longer, the peak heat release rate is 16.5 J/deg. higher, and the combustion duration is 5.96 °CA longer compared to diesel combustion.

This paper explores the application of thermoelectric cooler/heater (TEC) modules (Peltier heat pumps devices) to control core and winding temperatures, aiming to reduce the effects of thermal cycling and moisture issues that affect the life of electrical machines. Electrical windings in a motor will fail for a variety of reasons, and a major contributor to adverse effects of a motor's life is humidity. Due to thermal cycling, air containing moisture is drawn into a motor through a variety of access points such as terminal boxes, bearings, end covers and mounting systems. Even spare or replacement motors specially stored in heated spare equipment stores suffer from moisture ingress because of normal daily temperature changes. The better a machine can be kept warm, the less it is affected by moisture and the effects of mechanical stresses from cycling temperatures. A series of experiments were conducted, whereby a TEC was attached to a section of motor core and was set up to pump heat into the core segment. The thermal properties of the core material and the capacity to control winding temperatures along the core in specific locations and over time was measured. The results of this research demonstrate that the temperature of the motor can be tightly controlled, thus enabling the reduction of the effects of moisture, and reducing core and winding temperature differences. This has a positive influence in reducing the thermal stresses, which will result in improved insulation life and machine reliability.

High heat generation in surgical bone drilling causes thermal necrosis, thus impairing bone healing and implant reliability. Surgeons are often unaware of such in-situ drilling characteristics. Prediction and control of temperature is thus crucial for improved patient outcome. As a first step to this regard, the current paper aims to comprehensively explore the effect of the key parameters on bone drilling performance. Drilling tests were performed on Sawbone and bovine bone with the change of rotational speed (1000 - 2500 rpm), feedrate (30 - 60 mm/min) and drill bit (phi 3 and 4 mm). Drilling temperature, force, thermal necrosis exposure probability and chip formation were analyzed. Sawbone was found to reveal significantly less temperature and force generation than bovine bone, and hence the analysis presented was focused on bovine bone. Rotational speed and feedrate showed an opposing effect. Higher speed increased temperature but decreased force, while higher feedrate reduced temperature but increased force. Drilling with lower spindle speed and intermediate feedrate was shown to have a low chance for thermal necrosis. Bone chip formation changed from continuous (shearing) to broken type (fracturing) when the speed was increased from 1000 to 2500 rpm. If not necessary, smaller drill bit was suggested to minimize the underlying effect. These preliminary findings appeared to guide one to develop and optimize a prediction model for surgeons to estimate and control temperature and force for a safe bone drilling, which is the key focus of the author's future work.

Internal losses in motor windings and cores result in unwanted heat. According to International Energy Agency, majority of motors in service today are AC induction motors between 0.75 and 375 kW. For these motors, internal losses (heat) are conducted to the surrounding environment by internal conduction to the casing and then to the surrounding environment by convection. For small motors of up to 5 kW, the cores are mounted in a simple round housing and as they get larger the housings are ribbed and external fans are installed. Motors are designed assuming an environmental maximum temperature of 40 °C and with a hot spot allowance of 10 °C can withstand up to 155 °C (class F) at the winding position. However, due to changes in environmental temperatures, system voltage variations and harmonics, winding temperatures often exceed this limit. Consequently, this range of motors last only approximately 3 years. This paper investigates the possible application of thermoelectric cooler (TEC) to increase the heat flow from the core to reduce the temperature at the winding position, potentially providing longer insulation and motor life. For small motors, they can be simply attached to the outer surface. For larger motors with frames incorporating cooling ribs, they could be installed between the cores and the frames. The experimental results found that the application of TEC reduces the winding temperatures by 25.4%. Ability to incorporate this technology allows the opportunity to add a controlled device that can reduce temperatures at the windings when the temperatures exceed normal ratings.

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. Then, the geometry is imported in ANSYS FORTE and simulations are carried out with diesel and compared with the experimental data which shows around 97% accuracy. Then, a CHEMKIN file is created to use POD in ANSYS FORTE. Thereafter, simulations are carried out with POD with standard engine settings and compared with diesel. The engine performances are lower with POD due to lower calorific value, higher viscosity, higher density and heavier molecules present in POD. POD has a higher cetane number which is beneficial from the combustion point of view. In-cylinder pressure, temperature and accumulated heat release vs. crank angle are plotted to find out the combustion characteristics of POD and compared with diesel. The liquid and vapor penetration length, droplet size and mass are also plotted and compared with diesel.

Bone drilling is an important step in orthopedic surgeries for the reconstruction and repair of fractured bones. The main concern in bone drilling is to create holes without causing minimum damage to the bone tissues. It is well reported that high temperature and high force in drilling cause bone thermal necrosis leading to the delayed bone healing and implant failure. In the past, a significant amount of research has been conducted to understand and mitigate the issues in bone drilling. However, the current practice in bone drilling is that medical surgeons still rely on their own experience and feeling, which often causes unwanted damage to the bone. The present paper aims to provide a comprehensive review of surgical bone drilling and impending factors affecting drilling and biological performance of the bone. Current protocols and practices in tackling issues around drilling are discussed and assessed in terms of results obtained in both experimental and computational domains. This pragmatic discussion will signify the importance and challenges ahead in empowering medical surgeons to enable improved surgical outcome. Furthermore, the findings of this extensive review are expected to drive further exploration of new opportunities for developing advanced bone drilling system integrated with intelligent sensors and control technology.

Due to skyrocketing fuel price and demand, engine manufacturers and researchers have been thriving to find alternative sources of fuel for internal combustion engines. Biodiesel and vegetable-based fuels are prospective substitutes for petro-diesel fuel for compressions ignition (CI) or diesel engines, and favourable over petro-diesel fuel in terms of sustainability and environmental friendliness. It is found from the literatures that higher viscous fuels (HVFs) and biodiesel fuels have substandard engine performance and emissions especially in the case of brake specific fuel consumption (BSFC), torque and NOx emissions compared to those of the engines using petro-diesel. This is mainly due to their higher viscosity and density as well as lower volatility and calorific value and thus, they are termed as higher viscous fuels. Furthermore, the higher viscosity and density of HVFs retard the combustion efficiency since HVFs are less prone to evaporate, diffuse and mix properly with the in-cylinder air. Based on these findings, researchers have put effort into improving the performance of CI engines running with HVFs. Generally, three techniques are very popular by the researchers, namely, blending the HVFs with petro-diesel (known as fuel blend), preheating the HVFs, and altering the injection strategy from the original engine-settings for petro-diesel operation. In this paper, a comprehensive review is presented on these techniques to improve the performance of CI engines run on HVFs.

In this research, intake runner length, and valve timing are varied individually and simultaneously over a range of values to capitalize the induction pressure waves to boost volumetric efficiency. 1-D model of the stock engine built in Ricardo Wave software is validated with 90% accuracy against experimental test results. The volumetric efficiency of the engine is boosted by an average of 3.2% over the speed range of the engine when infinitely variable runner lengths are used. When only two variations in runner length are used, the volumetric efficiency has boosted by around 1.4% on average. On the other hand, when infinitely variable valve timings along with two variations in runner lengths are used, the volumetric efficiency has boosted by an average of 7.78 %. Due to the existence of two different runner lengths, the span of variations required in valve timing is reduced further optimizing the volumetric efficiency. However, to ensure feasibility of the design, manufacturing, assembly and operation, it is better to use only two valve timings. The co-presence of only two different runner lengths and two different valve-opening timings, the average boost of 5.40 % in volumetric efficiency throughout the operating speed range of the engine is encountered.

Physico-chemical properties of microalgae biodiesel depend on the microalgae species and oil extraction method. Dioctyl phthalate (DOP) is a clear, colourless and viscous liquid as a plasticizer. It is used in the processing of polyvinyl chloride (PVC) resin and polymers. A new potential biofuel, hydrothermally liquefied microalgae bio-oil can contain nearly 11% (by mass) of DOP. This study investigated the feasibility of using up to 20% DOP blended in 80% diesel fuel (v/v) in an existing diesel engine, and assessed the performance and exhaust emissions. Despite reasonable differences in density, viscosity, surface tension, and boiling point, blends of DOP and diesel fuel were found to be entirely miscible and no separation was observed at any stage during prolonged miscibility tests. The engine test study found a slight decrease in peak cylinder pressure, brake, and indicated mean effective pressure, indicated power, brake power, and indicated and brake thermal efficiency with DOP blended fuels, where the specific fuel consumption increased. This is due to the presence of 16.4% oxygen in neat DOP, responsible for the relatively lower heating value, compared to that of diesel. The emission tests revealed a slight increase in nitrogen oxides (NOx) and carbon monoxide (CO) emissions from DOP blended fuels. However, particulate matter (PM) emissions were lower from DOP blended fuels, although some inconsistency in particle number (PN) was present among different engine loads.