Large Marine Diesel Research Articles

Thermal-fluid-structure coupling simulation of piston in large marine diesel engine

Abstract Traditionally, most simulation approaches for pistons are conducted based on thermal-structure coupling, where the cooling boundary conditions are determined by empirical formulas. However, these approaches often suffer some decreases in the accuracy of the simulation results. Aiming at the problem, this paper conducts a thermal-fluid-structure coupling simulation method for the piston of a large marine diesel engine, which employs computational fluid dynamics to identify the cooling boundary conditions. Firstly, the solid and fluid models are established. Then, the cooling process of the piston chamber is simulated, with the temperature and heat transfer coefficients being mapped onto the solid component. Finally, loads and constraints are imposed on the solid component to accomplish the simulation. Under the presumed simulation conditions, the obtained coupling stresses are within the permissible range, with a maximum value of 419.68 MPa, and the dangerous region occurs at the junction of the piston head and the cooling chamber.

Study of Effects on Performances and Emissions of a Large Marine Diesel Engine Partially Fuelled with Biodiesel B20 and Methanol

The impact of fossil fuel utilisation in different combustion systems on climate change due to greenhouse gas accumulation in the atmosphere is rather evident. A part of these gases comes from the large engines used for propulsion in marine applications. In the continuous global effort made by engine manufacturers to mitigate this negative impact, one way is represented by the utilisation of alternative fuels such as biodiesel and methanol, based on dedicated research to fulfil the more stringent regulations concerning pollutant emissions issued by piston heat engines. In this study, a numerical investigation was conducted on a four-stroke large marine diesel engine (ALCO 16V 251C) at several engine speeds and full load conditions. Different blends of diesel–methanol and biodiesel B20–methanol with methanol mass fractions of 10% and 20% were considered for theoretical analysis in two techniques of methanol supply: direct injection mode of a blend of base fuel diesel/biodiesel B20 with methanol and injection of methanol after the intercooler, and direct injection of the base fuel. The results show that, if 10% in power loss can be acceptable, then for diesel–methanol 10%, in the direct injection technology, the NOx emission can be reduced up to 19%, but with a compromise of an 8% increase in SOOT emission, while for biodiesel B20–methanol 10%, with the same direct injection method, the NOx emissions increase by up to 58% with the benefit of reducing SOOT by up to 23% relative to the original diesel fuel operation. For a 20% methanol fraction in blend fuel, the drop in power is more than 10% regardless of the method of methanol supply and the base fuel, diesel, or B20 used.

Comparative study of machine learning techniques to predict fuel consumption of a marine diesel engine

The motivation of this study is to compare four different machine learning algorithms which are support vector regression, multiple linear regression, J48 pruned tree, and M5 Rules, to predict the fuel consumption (FC) of a large marine diesel engine utilized as the main engine on a tanker vessel. This study aims to fill a literature gap by comparing two algorithms, which have not been used for this problem in the rule and tree-based literature, with the other two frequently used algorithms. The data gathered from noon reports and the logbook of an oceangoing tanker vessel involves the operational and environmental parameters. The model performances, prediction accuracy, and error deviations on the test set are demonstrated. The importance of each feature on fuel consumption is discussed regarding the rules created by the algorithms. The M5 Rules algorithm has the highest performance with the truest predictions with a correlation score of 0.9666, mean absolute error of 2.3536, and root mean squared error of 3.3947. Slip, speed, distance, and wind direction are the operational and environmental dependent variables that have more influence on the FC. M5 Rules algorithm has provided a clear sorting for each feature's importance regarding conditions.

Experimental Study of Identifying Emission Sources of Acoustic Signals on the Cylinder Body of a Two-Stroke Marine Diesel Engine

In this paper, an experimental method was utilized to investigate acoustic emission (AE) characteristics and to identify emission sources of the nonlinear AE signal on the cylinder body of a large low-speed two-stroke marine diesel engine in real-working conditions on the sea in misfiring and normal firing modes. Measurements focused on the AE signal acquired in a transverse direction in low-frequency (20–80 kHz), medium-frequency (100–400 kHz) and high-frequency (400–900 kHz) ranges. The collected signals were analyzed on the crank angle and crank angle-frequency domains. The results showed that all potential sources of the nonlinear AE signal could be mapped in the low-frequency range. However, only the AE signal caused by the combustion process at around the top dead center could be well-observed in the medium-to-high-frequency range. The findings also revealed that in normal firing conditions, the AE energy radiated by friction in the down-stroke period was smaller than in the up-stroke process due to gas-sealing forces. Moreover, the AE energy in the misfiring condition was higher than in the normal firing state. These outcomes considerably contributed understandings to characteristics of friction and wear around the mid-stroke area of the cylinder on a two-stroke marine diesel engine.

Instantaneous Angular Speed-Based Fault Diagnosis of Multicylinder Marine Diesel Engine Using Intrinsic Multiscale Dispersion Entropy

Due to coupling of multiple cylinders during operation and association of high environmental noise, the existing waveform analysis is inefficient to identify the working status of large multi-cylinder marine diesel engines (MCMDE). In order to solve this problem, a new framework named intrinsic multiscale dispersion entropy (IMDE) is proposed by calculating the multiscale dispersion entropy (MDE) of intrinsically reconstructed instantaneous angular speed (IAS) signal. Firstly, intrinsic characteristic scale decomposition (ICD) has been utilized to decompose an IAS signal into principal components. Then, appropriate components are selected for reconstruction of the intrinsically denoised IAS signal. Lastly, working state of the MCMDE is identified by quantifying the intrinsically reconstructed IAS signal with the help of multiscale dispersion entropy (MDE) leading to concept of IMDE. Simulation model corresponding to a v-16 cylinder engine and experimental data collected from a real life v-16-cylinder marine diesel engine are utilized for validation. Results show that the proposed IMDE can extract the effective fault features under different working conditions and has the highest classification accuracy in compare to other existing techniques: MDE, MSE and MFE.

The Impact of Ammonia Fuel on Marine Engine Lubrication: An Artificial Lubricant Ageing Approach

Ammonia is a prospective zero-carbon-emission fuel for use in large marine diesel engines. Current research focuses on several technical aspects, such as injection strategies or exhaust gas aftertreatment options, but investigations regarding the impact of ammonia on engine oil degradation are largely absent from the literature. This study provides a methodology with which to evaluate this phenomenon via artificial oil alteration. By using an admixture of various contaminations to air, such as ammonia and its partial combustion product nitrogen dioxide, their respective impacts on chemical oil degradation were assessed. Subsequently, the lubricating performance of altered oils was investigated, with a focus on corrosion properties, deposit formation, and load-bearing capability. Although the application of a stoichiometric ammonia–air mixture resulted in less pronounced thermo-oxidative degradation compared to alteration with neat air, static and dynamic deposit formation as well as corrosion properties and load-bearing capability were severely impacted by the presence of ammonia. On the contrary, nitrogen dioxide contamination resulted in higher oxidation and acidification of the oil, but altered samples performed considerably better than ammonia-altered aliquots in terms of coking tendencies, corrosivity, and load bearing.

Variational time–frequency adaptive decomposition of machine multi-impact vibration signals

The vibration signal of a mechanical equipment shell displays multi-impact coupling characteristics, when reciprocating mechanical vibration signals of large marine diesel engines and petrochemical reciprocating compressors, which exhibits the characteristics of nonstationarity, strong coupling, and strong interference in the time–frequency domain. Signal decomposition and multi-source impact identification have great significance for early fault diagnosis. However, existing decomposition methods for extracting fault frequency bands cannot satisfy demands for extracting impacts from the multi-source impact signals of reciprocating machinery. In this study, variational time–frequency adaptive decomposition (VTFAD) for multi-impact vibration signals is established to decompose and extract single-impact components. A variational model based on the minimization of a spectral center moment is proposed based on the two-dimensional morphological characteristics of energy concentration and discrete distribution in the time–frequency spectrum of the impact signal. An iterative solution is obtained using the alternating direction multiplier method; the time–frequency center and effective time–frequency domain components of the impact are calculated adaptively. A parameter optimization selection scheme is designed for selecting the number of time–frequency domain decompositions and quadratic penalty factor in the optimization process. The test of simulated mechanical multi-impact signals demonstrated that the proposed method can adaptively and accurately identify the time–frequency centers and time–frequency domain characteristics of the impacts in multi-impact vibration signals. VTFAD was applied to a diesel engine connecting the rod-bearing wear-fault vibration signal. The results show that VTFAD can effectively identify the new impacts caused by the fault and accurately extract the key characteristics of the impacts.

Study on the Cumulative Effects of Using a High-Efficiency Turbocharger and Biodiesel B20 Fuelling on Performance and Emissions of a Large Marine Diesel Engine

The marine sector represents probably the most powerful segment of international transport. Most ships use diesel engines for propulsion. Pollutant emission regulations with their continuous decline of acceptable limits put huge pressure on engine manufacturers. The use of low-quality fuels makes the marine sector a significant contributor to global pollution. The present study shows how turbocharger operating parameters and replacing diesel fuel with biodiesel B20 (20% oil and 80% diesel volumetric fractions) affect the performance, efficiency and pollutant emissions of a four-stroke diesel engine ALCO V16 251F for marine application. A combustion model developed with the AVL BOOST software was used to perform calculations using diesel fuel and biodiesel B20 for different turbocharger characteristics and injection timings. The model was calibrated against experimental data measured on a tested engine at the application site using diesel fuel and operating in a stationary condition of full load at 600, 700 and 800 rpm engine speeds. The results show that the cumulative effects of using an improved turbocharger associated with B20 fuelling under optimized injection timings could provide reductions of 45% for soot and 5% for NOx, while maintaining the same engine performance obtained with diesel fuel operation.

Waste heat recovery from marine main medium speed engine block. Energy, exergy, economic and environmental (4E) assessment – Case study

90% of traded goods are transported by ship, the vast majority of which are propelled by diesel engines with an energy efficiency of no more than 50%. Among the developments to increase it, waste heat recovery (WHR) technologies still have room to increase overall efficiency.This study looks into the feasibility of recovering waste heat radiated by the block of a large marine diesel engine. An energy, exergy, economic and environmental (4E) assessment is presented. The analysis identifies the amount of heat from the block which is possible to recover and looks into the cost and CO2 emissions reduction gained when waste energy is reused. A cement carrier vessel propelled by two four-stroke engines with 3000 kW nominal rating is used as case study vessel. From onboard measurements and fluids analysis, results unveil the overall heat radiated from engine block and coolers to be 14.93% of total. Scale factor makes available up to 369 kW of radiated heat. Fuel savings achieved by engine block heat recovery will lead to reductions of 3.31% of the total CO2 and 8.33% of the specific NOx gases emitted. Technological means of heat recovery can range from the temper of hot water to use in vessel's accommodation to the recharge of electric batteries by means of thermoelectric generators.

On some possible effects of using renewable oxygenated fuels in a large marine diesel engine

For the continuous reduction of the anthropogenic CO2 large diesel engines require the use of alternative fuels such as oxygenated renewable biofuels. These types of fuels will help in fulfilling future standards of regulated pollutant emissions for industrial, railways or marine applications In this sense, a theoretical investigation has been carried out on a four-stroke large marine diesel engine (nominal power of 2870kW at the rated speed of 1100 rpm). Different mixtures were investigated different mixtures of diesel–ethanol with ethanol volumetric fractions of 5%, 15%, 30%. The same ethanol fractions have been considered while replacing the diesel fuel with biodiesel B20 (20% rapeseed biofuel and 80% diesel fuel in volumetric fractions). The study covers two engine operating conditions characterized by full-load operation at the rated speed of 1100rpm and at mid-speed of 700rpm. It was found that a reasonable compromise can be achieved for an acceptable loss in power of 5% by using the diesel–ethanol15 mixture, which reduces NOx by 9.69%. Using the B20–ethanol05 mixture, will reduces Soot by 19.28% but increases NOx by 21.94% at low speed 700 rpm. At a high engine speed of 1100rpm, for the same both fuels diesel–ethanol15 and B20–ethanol05, Soot increases by 7.84% while NOx decreases by 10.91%, respectively Soot decreases by 17.65% and NOx increases by 37.27%.

Efficiency, safety, and reliability analysis of turbocharging in a large container vessel

AbstractCommercial shipping is currently dominated by mega container vessels. The shipping industry has seen a 10‐fold increase in the size of containers over the last four decades. These vessels are propelled by large marine diesel engines, hereafter referred to as the main engine. The performance of the main engine is determined by its subsystems. An important part of the main engine is the turbocharging system, which contributes to its safety, efficiency, and reliability. In this study, the effectiveness and reliability of the turbocharging system are evaluated. The Australian Maritime College has a Kongsberg Engine Simulator that can produce a variety of malfunctions on a running engine's turbocharging system. Analyzing the results obtained from the simulator determines the efficiency of the turbochargers. The study will provide recommendations for improving the safety of the turbocharging system for better performance to be achieved by the turbochargers, leading to an improvement in the main engine's performance. Last, the reliability of the turbocharging system is evaluated quantitatively using a fault tree analysis and reliability block diagrams. This will enable an optimum maintenance strategy to be established to ensure the safe operation of the vessel.

Parametric investigation of a large marine two-stroke diesel engine equipped with exhaust gas recirculation and turbocharger cut out systems

Albeit the exhaust gas recirculation (EGR) is widely used to reduce the nitrogen oxides (NOx) emissions from large marine two-stroke engines, several challenges emerge for the engine–turbocharging system matching considering the contradictory requirements of the engine and its subsystems operation. Such challenges become more pronounced in complex engine configurations that include parallel turbochargers and the EGR system along with cut out and bypass branches. This study aims at parametrically investigating a large marine two-stroke engine equipped with an EGR system, two parallel turbochargers of different size, and cut out branches. The turbocharging system characteristics are selected targeting the minimisation of the engine specific fuel consumption whilst ensuring compliance with the respective NOx emissions limits and satisfying imposed constraints for the compressors operation. A detailed model of the zero/one dimensional type is developed in the GT-SUITE software and used to simulate the investigated engine along with its subsystems. Simulation runs are performed to investigate the engine with four different turbocharger configurations of varying capacity ratio and under various operating conditions in terms of the EGR rate and engine load. The simulation results are analysed to reveal the impact of the turbocharger selection of the engine performance and emissions parameters. Furthermore, modulation schemes with EGR blower speed control, exhaust gas bypass and cylinder bypass are investigated to overcome the mismatch on the engine components flow rates and avoid turbocharger operational issues. The derived results demonstrate that the lowest weighted BSFC is achieved for the case of 70:30 capacity ratio between the large and small turbochargers, whilst the engine operation with the EGR is associated with a 2.6% penalty in the weighted BSFC. The EGR blower speed control is found sufficient to avoid the compressor overspeed at high engine loads exhibiting the lower BSFC penalty, whereas the cylinder bypass control is appropriate for controlling the compressor speed at low engine loads. This study contributes on delineating the underlying parameters and interactions between the engine components for the investigated marine two-stroke engine and provides recommendations for the engine–turbocharging system matching procedure.

Research on the correlation between fuel injection quantity and key structural parameters for the fuel system of marine diesel engines

In order to demonstrate the relationship between the fuel injection quantity and the structural parameters of the fuel system for large marine diesel engines, an AMESim model of a double-valve controlled fuel system is proposed. The accuracy of the model is validated in view of fuel injection quantity and system pressures. The correlation analysis is performed to illustrate the effects of single parameters and the interactions between different parameters on the fuel injection quantity. Considering the high calculation cost of the simulation model, the prediction model between the fuel injection quantity and the structural parameters for each working condition is obtained based on D-optimal design of experiments and the response surface methodology in this article. For the maximum deviation between the calculated and predicted fuel injection quantity is only 4.27%, the prediction models could be used for further analysis. And the results show that the diameters of high-pressure fuel tube (HPFT), small and big ends of pressure amplification piston (PAP) are the key single parameters. The absolute values of their correlation coefficients are between 0.77 and 0.87, between 0.22 and 0.43 and between 0.14 and 0.26 respectively. The correlation coefficients for the other parameters are all relatively small. For interactive parameters, the absolute values for all the correlation coefficients are less than 0.1. And the interactions between the diameters of big and small diameters of PAP, between the diameter of small end of PAP and the diameter of HPFT, between the diameter of HPFT and the pre-tightening force of needle spring influence the fuel injection quantity relatively obviously.

Multi-criteria assessment and optimization of waste heat recovery for large marine diesel engines

The energy crisis combined with increasingly severe environment pollution have highlighted the significance of the energy conservation and emission reduction in shipping industry. To improve the energy utilization rate and reduce pollution, a dual-pressure organic Rankine cycle system is proposed to reuse the heat of exhaust gas in marine engines. Many researches focused on the thermodynamics and thermos-economics of the waste heat recovery system, and optimized it from these two goals to recover more energy and decrease cost. However, the impact of the system itself on the environment, which was significant to assess the greenness, was often neglected in these studies. The system with high energy recovery rate may also cause serious environment pollution in the manufacturing or operation process, hence the environmental factor should be taken into account in the optimization. To solve the problems, an evaluation method combined thermodynamics, economics and environment is proposed. The parametric study of the dual-pressure organic Rankine cycle system with six common used working fluids is assessed by this method. Finally, taking the indicators of evaluation method as objective function, the multi-objective optimization method is conducted to figure out the optimum operation conditions for the system. Results show cyclopentane is the optimal working fluid considering thermodynamic, economic and environmental properties. Under the conditions of the evaporation pressure in high-pressure circuit 2.79 MPa, the evaporation pressure in low-pressure circuit 1.97 MPa, the condensation temperature 35 °C, the superheating temperature 1.2 °C, the system obtains a good performance with exergy efficiency 60.24%, electricity production cost 0.167 $/kWh and the environmental impact of net power output 11831.9 mPts/GJ.

300 kW급 선박용 디젤엔진 저배압 미세먼지저감 전기집진장치 설계

In recent years, regulations of environmental pollution have gradually been strengthened worldwide. The International Maritime Organization (IMO) has adopted the “agreement of air pollution prevention of ships” which regulates the emission of air pollutants from ships. Regulation of nitrogen oxide (NOx) emissions of large marine diesel engines below 130 rpm have been strengthened. In the case of large marine diesel engines, the regulations for Tier-III, which took effect in January 2016. It has been reinforced to less than 14.4 g/Kwh, which is a regulation that must reduce nitrogen oxides by more than 80% compared to Tier-II. In addition, since 2020, the emission of sulfur oxides (SOx) has been regulated to less than 0.5% and the ships sailing in coastal and exclusive economic zones are regulated to be limited to 0.05%. In order to reduce the emission of nitrogen oxides (NOx) and sulfur oxides (SOx) generated from ships, it is essential to install post-treatment devices such as SCR and scrubber. The annual average amount of particulate matter (PM) in Korea is 24.8 ㎍/㎥, which is said to be the worst among the OECD countries and the 26th most serious in the world. The government aims to reduce domestic particulate matter (PM) emissions by 30% until 2022. Currently, the port cities of Busan, Incheon, and Ulsan have poor air quality, and air pollutants generated from ships are introduced and are affected by serious environmental pollution. In the future, regulations on particulate matter (PM) are expected as environmental regulations are strengthened in the International Maritime Organization as well. Currently, most studies on post-treatment devices to reduce nitrogen oxides (NOx) and sulfur oxides (SOx) generated from ships are conducted; however, there is almost no research on the reduction of particulate matter (PM) for ships. Therefore, in this study, it was conducted on an electric precipitator for reducing particulate matter (PM) in a 300 kW class of marine diesel engine. The electrostatic precipitator is a device that collects particulate matter (PM) from a collecting plate by causing a corona discharge phenomenon. In this study, three types of dust collector plates and electrode plates, which are components of the electrostatic precipitator, were designed and structural stability was derived through numerical analysis.

Bench experimental research of cylinder oil on large marine diesel engines

To lower the risks of the real ship test of the cylinder oil of large marine low-speed two-stroke marine diesel engine, A 6S50ME marine diesel engine was selected to do bench test about cylinder oil. In the calibration condition, the test cylinder oil and the reference cylinder oil were compared. The test results show that the wear amount of cylinder liners, piston rings and piston-ring-grooves is consistent with the wear condition judged by the metal element content detected by the residual oil of the cylinder. At the same time, combined with the evaluation result of the detergency and dispersibility of the cylinder oil, it can effectively judge whether the oil product can be tested on the ship. Since wear volume of element Cr and Fe tends to the stabilization after 60 hours, so it is feasible to set the diesel engine bench test at 100 hours. In addition, special attention should be paid to the control of water outlet temperature and exhaust gas temperature in the test. The cylinder oil evaluated in the above way meets the requirements of OEM after the actual ship test. Thus, the assessment method of cylinder oil based on the bench test is feasible, and can greatly shorten the test time and reduce the test cost.

Impact of Defective Turbocharging System on the Safety and Reliability of Large Marine Diesel Engine

Today huge capacity sea-going vessels are propelled by mega high-powered marine diesel ‎engines, referred to as Main Engine. Turbocharging system is an integral part of large marine diesel engine plant, ‎contributing to their safety, reliability, and efficiency. Defects in the turbocharging system ‎could result in higher fuel consumption, erratic running of the Main Engine, and in the worst ‎scenario may result in the stoppage of the Main Engine at sea. An inefficient turbocharging system may also cause major damage to turbochargers, resulting in undesirable accidents out at sea. To ‎avoid such undesirable accidents and ensure smooth operations of the Main Engine, it is required to ‎address this concern. The aim of this research is to study the turbocharging system for a ‎large Main Engine using a Kongsberg engine ‎simulator. Various malfunction of the ‎Turbocharging system is considered, relevant data is collected and analysed. ‎Moreover, a Fault Tree Analysis, (FTA) is considered to identify the top undesirable event ‎which is the failure of the Main Engine. Based on the results of this study, various steps ‎are suggested to avoid failure of the Main Engine due to the defective turbocharging ‎system.‎

Energy and exergy analysis of a novel steam injected turbocompounding system applied on the marine two-stroke diesel engine

Waste heat recovery from marine power plants has been recognized as an effective approach to reduce CO2 emissions from ships. This paper proposes a novel steam injected turbocompounding system for recovering waste heat from the large marine two-stroke diesel engine. First, a sophisticated thermodynamic model that integrates the topping in-cylinder Diesel cycle and the bottoming steam injected Brayton cycle is built based on energy and exergy analysis. Parametric studies of the bottoming steam injected Brayton cycle are then conducted with special focuses on the steam generation and injection processes, followed by a comparison between the conventional turbocompounding system and the novel steam injected version. It is concluded that parameters of generated steam are mainly restricted by the design constraints of the exhaust gas boiler and the heat source temperature. Exergy destruction during the steam injection process accounts for a large proportion of the injected steam exergy. The injected steam mass flow rate plays a significant role in determining the exergy distributions in the turbocompounding system, while the steam temperature and pressure have limited effects. Compared to the base engine, the fuel consumption could be decreased by 5.1% at the rated speed with the novel steam injected turbocompounding system, while the improvement is around 3.3% with the conventional turbocompounding system.

Design and optimisation of an advanced waste heat cascade utilisation system for a large marine diesel engine

Growing energy shortages severely restricting the sustainable development of human beings, improving energy efficiency has become an urgent issue. To improve energy efficiency, the dual-pressure organic Rankine cycle, which is an efficient waste heat recovery technique for ships, has received increasing attention. Most researchers have investigated the dual-pressure organic Rankine cycle with pure working fluids, which do not yield the best thermodynamic and economic performance. In addition, some low-grade waste heat sources in the engine have been neglected. To completely recover the waste heat energy of marine engines, a novel waste heat recovery technique with a dual-pressure organic Rankine cycle system, desalination plant, and two-bed regenerative adsorption refrigeration device is presented for recovering residual heat from the exhaust gas, jacket water, charge air, and lubricating oil. Based on a comparison of the thermodynamic performance, safety, and environmental effects, the zeotropic working fluid pair dimethyl carbonate/perfluoropropane is selected. The mathematical model of the proposed integrated system is evaluated to ensure accuracy, and its critical parameters are analysed based on its thermodynamic and economic performance. A multi-objective artificial bee colony algorithm is adopted to optimise the system. The results show that the proposed integrated system can recover 354.65 kW net power and increase the thermal efficiency by 4.2% on average; at the most frequently used engine load, a refrigeration capacity of 88 kW and a fresh water rate of 146 kg/h are achieved. This work promotes the development of the energy recycling.

Thermoeconomic analysis of a new waste heat recovery system for large marine diesel engine and comparison with two other configurations

ABSTRACT The utilization of waste energy sources and their treatment are very important in marine science due to their numerous benefits such as energy saving and feasible fuel conservation. Hence, this paper proposes three different configurations of waste heat recovery systems for the successful recovery of waste heat sources in diesel engines to obtain the highest level of power generation from the ship engines. The results of this study indicate that the new organic Rankine cycle system with the utilization of jacket cooling water presents better thermodynamic efficiencies and lower unit power cost in comparison with two other systems. Among the evaluated refrigerants, the R600 shows better thermoeconomic characteristics among other refrigerants. Several analyses show that the utilization of water jacket cooling beside the exhaust gases of the engine resulted in the fuel conservation of 209486 gallons per year of operation, which is about 23.3% higher than the base system without jacket cooling exchanger. Furthermore, it is observed that increasing the engine loading improves the net power output and also the payback period of the systems. This method might provide researchers with information to assess the benefit and the cost of each configuration modification and determine the direction of further improvement.