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In this paper, operational data of a natural gas-fired generation engine at 2 MW of power is presented. This engine is used as part of the power supply system of a flexible packaging transformation and conversion plant. This plant, besides having the power supply generated by the engine, receives electrical energy from the network. The data collected from this engine corresponds to measurements taken before, during and after engine stops, whether due to engine maintenance stops, engine failures or external power grid failures. The measurement was made every 10 seconds, and for the storage of these data a data acquisition software was used, which, besides allowing to take these data, shows in real time the electrical behavior of the electrical supply system, as well as the mechanical behavior of the engine.

The electric load demand on marine vessels is constantly changing during some operational modes, such as in harsh weather or complex operations. Therefore, diesel engines are typically used to handle these variations. Gas engines reduce the CO2 due to lower carbon content in LNG compared with diesel oil. However, they may not be able to handle the load variations of a marine power plant. There are multiple other energy sources with strict rate constraints, such as slow speed diesel engines and fuel cells. In such cases, a battery may be used to take care of the variations, while the generator set produces a slowly varying power. In this paper, a common power flow controller for the battery and the generator set is proposed. It utilizes the rotating inertia in the generator set as energy storage, in addition to a battery. This is done by allowing a small excursion in the speed of the generator set; the speed change will change the kinetic energy of the generator set and this is used analogously to energy storage. The controller is compared with a baseline controller based on virtual inertia and speed droop. A simulation study is included to demonstrate the performance of the control methods. The simulation study shows that the gas engine (with strict constraints) is not able to handle the given load series. Nonetheless, it can be used in combination with a battery to handle the variations. The power plant can handle a measured load series from an offshore vessel when either speed-droop control or model predictive control is used. However, the study indicates that by using MPC, the aging of the batteries and fuel rate variations can be reduced.

The creation of modern high-powered gas and gas-diesel engines is associated with the solution of two main tasks – the elimination of abnormal combustion and reduction of engine thermal factor. The paper discusses ways to reduce exhaust gas temperatures, methods to eliminate hot-tube ignition and detonation in single fuel gas engines. The ways of reducing exhaust gas temperatures, reducing the thermal factor of diesel injectors (pressure, duration of injection) and detonation issues in two-fuel gas-diesel engines are considered. The results of computational and experimental studies are presented. It is shown that due to the optimization of intake systems, fuel supply and control algorithms it is possible to significantly reduce the thermal stress of gas and gas-diesel engines, while ensuring the achievement of high values of the average effective cycle pressure up to 28 bar and the achievement of high volume power up to 43 kW/l.

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This paper presents a methodology for predictive and prescriptive analytics of a gas turbine. The methodology is based on a combination of physics-based and data-driven modeling using machine learning techniques. Combining these approaches results in a set of reliable, fast, and continuously updating models for prescriptive analytics. The methodology is demonstrated with a case study of a jet-engine power plant preventive maintenance and diagnosis of its flame tube. The developed approach allows not just to analyze and predict some problems in the combustion chamber, but also to identify a particular flame tube to be repaired or replaced and plan maintenance actions in advance. [ABSTRACT FROM AUTHOR]

Decreasing energy consumption, greenhouse gases, and fuel cost motivate researchers toward using Combined Heat and Power (CHP) systems. Of course, finding suitable scenarios for consumption, sales, and investment is very important in using the CHP system. In some countries like Iran due to the non-consideration of the environmental taxes and low fuel prices implementing the CHP projects is still a challenge. Although the economic and technical benefits of CHP projects are truly registered, the methods of financing are still a dilemma. In the present study, the feasibility of using the gas engine to generate electricity and recovering the exhaust waste heat to supply the required heat of a car-manufacturing plant in northeastern Iran was investigated. The different numbers of gas engines to supply heat and electricity were analyzed. Based on the results, the use of three gas engines supplied more than 75% of the annual required heat of the car factory. Also, two different investment scenarios for attracting investors were proposed. These scenarios improved the conditions to attract the investors via displaying the financing landscapes of the project and providing its detailed information. Considering the results, when the car factory is the investor, the strategy of electricity sales to the grid and exhaust heat consumption in the car factory is the most cost-effective selection. [ABSTRACT FROM AUTHOR]

This study presents a new technique for optimal sizing of the gas turbine as the primary mover of a combined cooling heating and power (CCHP) system in a selected commercial building. Because of the vital effect of four substantial parameters including energetic, energetic, economic, and environmental (4E analysis), they used for optimum sizing of the gas engine for the CCHP system. The optimization process has been performed by a newly developed meta‐heuristic, called Opposition‐Based Learning and Lévy flight owl search algorithm (OLOSA) for an industrial building in Iran. During the optimization, eight constraints from the 4E analysis have been considered. Final results of the proposed OLOSA have been compared with genetic algorithm (GA) and the results declare that the optimal size for the gas engine based on OLOSA and GA for the cost value are 0.1923 and 0.5622, respectively and the optimal value of the gas engine is achieved 90.16 kW and is achieved after 9 generations and 39 generations, respectively which shows the excellence of the presented OLOSA toward GA in both terms of accuracy and convergence. [ABSTRACT FROM AUTHOR]

Prechamber ignition technology receives increasing attention due to its considerable improvement on engine combustion efficiency and stability. However, fundamental knowledge concerning flame propagation inside the pre-chamber and jet formation in the main chamber is still quite scarce. In this study, a small (\0.5% VTDC) un-scavenged pre-chamber was tested in a medium size gas engine with pressure transducers installed in both pre- and main chamber. Three-dimensional computational reactive fluid dynamics Reynolds-averaged Navier--Stokes simulations were carried out using a level-set combustion model --G-equation -- towards improved understanding of the combustion processes occurring inside the pre and main chamber. The characteristics of the turbulence and the flame at locations just ahead of the propagating turbulent flame front were recorded and analysed by means of the well-known Borghi--Peters diagram. The results revealed that the characteristics of the flame inside the pre-chamber differed greatly from those inside the main chamber due to considerably reduced turbulent length scales. In addition, a wide range of turbulence intensity and length scales are covered throughout the combustion event, presenting a significant challenge to modelling of flame--turbulence interaction. Various turbulent flame speed (ST) closures widely used in internal combustion engine simulation were therefore assessed and the ranges of their respective model constants explored. A correlation for ST is subsequently proposed by blending two formulations of Gülder developed for small and large scale turbulence, respectively, and compared to the well-known Peters correlation. With appropriate model constants, both successfully reproduce the pre and main chamber combustion for the reference case in terms of evolutions of cylinder pressure, heat release rate and pressure difference between pre and main chamber. Following successful calibration of the reference operating condition, variations in engine speed, load, spark timing and lambda were calculated using both correlations, demonstrating encouraging predictive capabilities of the proposed modelling strategy. [ABSTRACT FROM AUTHOR]

The biogas produced in municipal wastewater-treatment plants (WWTP) should be cleaned before it can be used as a fuel in internal combustion engines. Efficient running of such engines is possible only subject to using high quality biogas and lubricating oil. Otherwise, biogas impurities in course of complex chemical reactions may form deposits on various engine parts as well as seriously contaminate the lubricating oil. In this paper, mineral deposits containing high concentration of bismuth, silicon, sulphur, calcium and zinc are studied. Silicon deposits demonstrating strong friction properties are formed during combustion of volatile silica compounds. As these deposits build up, abrasion problems, ignition failure and even engine failure result. The bismuth containing deposits comes from bearings degradation, zinc and calcium were derived from the additives present in commercially available lubricating oil, while lead, aluminium, copper, nickel, iron and chromium were introduced by engine wear phenomena. The highest bismuth content was located at the engine cylinder heads and the lowest at the exhaust elements, whereas highest calcium content was registered on the pistons. Silicon containing deposits are highest in the exhaust and lowest at the engine head. Zinc deposits are highest at the piston. [ABSTRACT FROM AUTHOR]

Connection of small generating units in the medium voltage distribution system is increasing substantially. Such units, called distributed generation, can have a significant impact on, load flow, shortcircuit, voltage, frequency, power quality, stability, islanding and synchronized running, protection and reliability. In this study, the stability impact of a private sector power plant in Thrace region having synchronous generators driven by gas engine and gas turbine has been investigated in terms of fault ride through capability. Critical clearing time has been determined, once the criteria of fault ride through capability were explored. Grid operators do limit penetration levels of such plants and can also disconnect available units when grid fails. Stability is affected by voltage dip much worsely than penetration levels. It has been seen that the disconnection of power plants is not necessary, when the voltage dip restricted to 0,5 pu. Also that the stability is positively affected when the power factor is decreased to 0,8 from 1,0. The results also show that even 100% penetrated synchronous generator based power plants in distribution system do not affect stability badly in steady state operation. [ABSTRACT FROM AUTHOR]

A novel system for simultaneous generation of electricity, heating and cooling was proposed and optimized. The core of the system was a heat pump with a flash chamber. To provide the consumed electricity of heat pump and other needs of the building, a gas engine and a Photovoltaic system were used. In addition, a steam cycle was utilized to generate electricity from the exhaust gases of the engine. Considering the thermodynamic analysis, the heat pump had the best efficiency for the heating and cooling modes, when the pressures of flash chamber were 369 and 746 kPa, respectively. Moreover, the steam cycle had the best efficiency at the boiler pressure of 1985 kPa. According to a thermo-economic analysis, the optimum size of the engine was about 90 kW. Finally, a thermo-economic and environmental objective function was defined and the capacity of 80 kW was chosen as the optimum capacity for the gas engine. • Designing a novel cogeneration system. • Integrating a gas engine, a heat recovery Rankine cycle, a heat pump with economizer and a PV system together. • Optimizing different components based on Thermodynamic, Environmental and Economic concerns. • Introducing a novel 4E Objective Function to find the best capacity of gas engine. [ABSTRACT FROM AUTHOR]

Rescarch of the performance of the wheeled tractor diesel engine converted into a gas engine with spark ignition, which is supposed to improve the fuel economy and ecological indexes by the choice of expedient values of parameters of the conducting transmission and engine, is carried out. The rational values of parameters of the conducting transmission and gas engine are chosen and grounded at the acceleration of the wheeled tractor and rates of a withstand movement in operating terms after the criteria of minimum specific charges of fuel and harmful emissions.

In this paper, the results of modeling of the burning process in the piston engines whose working process is realized on the basis of various conceptual approaches are presented: in diesel with direct injection of the fuel; in a gas engine with spark ignition; and in a two-fuel engine (in the gas-diesel), where the mixture of natural gas and air ignites with the help of the fuse dose of the diesel fuel. The models of burning based on the different in-principle approaches are analyzed and used. Verification of the models is performed by a comparison of the results of modeling with the experimental diagrams. The specific values of the empirical coefficients, used in modeling of the burning process in the engines under study, are determined. The practical recommendations on the choice of the burning model depending on the working process conception are given. [ABSTRACT FROM AUTHOR]

Strict NO x emission regulations set for marine vessels by Tier III standard make ship owners/operators finding new efficient methods fulfilling these requirements. Utilization of LNG as main fuel at the moment is one of the most promising solutions with lean burn spark ignited (LBSI) engines and low pressure dual fuel (LPDF) ones being of primary choice. Technology provides not only low NO x levels, but also allows to reduce operational costs due to LNG currently being a cheaper fuel. The main drawback of low-pressure gas engines is rather high levels of methane slip, especially at low loads, as a result of poor fuel utilization due to low operational fuel–air ratios. Nevertheless, there are no standards that directly regulate methane slip for marine gas engines, but the topic starts to receive more and more attention due to the concerns associated with environmental effect of methane as well as due to ship operators analyzing ship data more thoroughly revealing substantial increase in gas fuel consumption at low loads. Presented study summarizes all gas engine technologies that are available for the maritime sector considering their current status and maturity and present a comprehensive measurement data summary for the main groups, namely LBSI and LPDF engines. The measurement data pool consists of both on-board and test-bed emission data revealing an interesting moments such as possible "overtuning" of engines for low NO x resulting in excessive levels of methane slip, importance of on-board measurements due to their more realistic nature, utilization of non-perfections, such as fixed emission weight factors for loads, and in Tier III regulations. The article also quantitatively indicates the progress in gas technology development and provides updated specific emission factors for the considered gas engine types. [ABSTRACT FROM AUTHOR]

Municipal solid waste (MSW) and charcoal can be used as a substitute fuel in a gas engine. In this work, performance of a downdraft gasifier and gas engine system operated on MSW briquette fuel was investigated. Experimental test was carried out on a 62 kW, four-cylinder, naturally aspirated engine coupled to a 20 kW dynamometer. The downdraft gasifier was used to generate producer gas from MSW briquettes and charcoal. The engine load was varied between 1.5-9.0 kW. Biomass consumption, producer gas production, cold gas efficiency, thermal efficiency of the gas engine, carbon monoxide (CO), hydrocarbon (HC) emissions and exhaust temperature were evaluated. The MSW briquette fuelled operation was compared against that with charcoal. It was found that, the use of MSW briquette led to lowering performance of the downdraft gasifier and gas engine system, in comparison with the use of charcoal. Maximum cold gas and thermal efficiencies obtained were 64.6% and 16% at 4.5 kW and 9 kW loading, respectively. The CO and HC emissions of the gas engine operated on MSW briquettes were higher than that on charcoal, while the exhaust temperatures were similar. [ABSTRACT FROM AUTHOR]

In order to investigate the grid integration of wind turbines (WT) of various scales and designs, a wind turbine emulator (WTE) is being built in Flensburg within the state-funded project GrinSH. The special feature of this WTE is the use of a large gas engine instead of an electric motor to emulate the behavior of a WT. In order to develop the controls of this innovative WTE and to design the upcoming test runs under safe conditions, a software in the loop model (SILM) was applied. This SILM contained a mathematical model of the wind turbine, mathematical models of the gas engine with an integrated controller, and a model of the generator and frequency converter unit, as well as a preventive modulator of the reference signal (PMRS). The PMRS module converts the reference signal of the emulated WT in such a way that the dynamics of the engine components can be calculated and balanced in advance to enable the required behavior of the entire SILM despite the dynamics of the gas engine. It was found that the PMRS module, developed and tested in this work, increased the ability of the WTE, based on a gas engine, to reproduce the dynamics of a WT.

This paper presents a methodology for predictive and prescriptive analytics of a gas turbine. The methodology is based on a combination of physics-based and data-driven modeling using machine learning techniques. Combining these approaches results in a set of reliable, fast, and continuously updating models for prescriptive analytics. The methodology is demonstrated with a case study of a jet-engine power plant preventive maintenance and diagnosis of its flame tube. The developed approach allows not just to analyze and predict some problems in the combustion chamber, but also to identify a particular flame tube to be repaired or replaced and plan maintenance actions in advance.

The object of research is an electronic microprocessor control system for gas internal combustion engines with spark ignition for operation on liquefied petroleum gas. The system consists of two main subsystems, the accumulative power supply common rail LPG injection subsystem and the contactless electronic ignition subsystem with a movable voltage distributor. In addition, the control system also includes a subsystem for controlling the filling of the cylinders with the charge of the working mixture, consisting of a throttle valve and an idle speed regulator with a conical damper. The control system, depending on the software version, is capable of providing group or sequential injection of liquefied petroleum gas into the inlet pipe of each cylinder in the area close to the inlet valve. Such a control system can be used when converting (re-equipping) both new diesel engines into spark-ignition gas engines, and those that are in operation. The feasibility of such a conversion is to reduce operating costs with powerful vehicles for diesel fuel, by replacing it with cheaper and environmentally friendly liquefied petroleum gas. To test the efficiency of the control system, a D-240-LPG-«B» model gas engine was developed and manufactured to operate on liquefied petroleum gas. The gas engine was converted on the basis of the D-240 transport diesel engine (atmospheric, four-stroke, liquid-cooled, 4-cylinder engine with a piston diameter of 110 mm and a stroke of 125 mm). Reducing the compression ratio of the diesel engine was achieved by modifying a semi-closed diesel combustion chamber of the TsNIDI type into an open combustion chamber in the form of an axisymmetric «truncated cone». For efficient control of three subsystems of the D-240-LPG-«B» model gas engine, an electronic microprocessor control unit of the Avenir Gaz 37 «B» model was developed and manufactured. The tests carried out on the D-240-LPG-«B» gas engine with the Avenir Gaz 37 «B» control unit showed the efficiency of using the electronic microprocessor control system. [ABSTRACT FROM AUTHOR]

A gas‐engine heat pump (GHP) is driven by an internal combustion engine fueled by natural gas. The objective of this research is to model the combustion and emission characteristics of a GHP engine and experimentally validate the model. In addition, the exhaust gas recirculation (EGR) and intake boost systems were numerically investigated to find an NO and NO2 (NOx) reduction strategy. The ignition and combustion processes were modeled using the level set method and the DPIK model, and experimental data was used for validation. The models predicted engine performance and emissions for various equivalence ratios and spark timing. The study results show that late spark timing leads to reductions of the indicated specific fuel consumption (ISFC) and NOx emission, and the ISFC and NOx emissions increase with the equivalence ratio until the equivalence ratio reaches 0.9. The indicated mean effective pressure (IMEP) increases with boost pressure and decreases with increase of EGR rate. Reductions of NOx emission and high IMEP can be achieved by employing a boost system and operating at the optimal operating point, from the performance and emission map.

A proper design of the engine intake system can provide the best engine performance. The modeling of inlet system is very important for the evaluation of the engine performance. It is known that the wave dynamics of intake system influences the engine performance. In the present work, the acoustic supercharging phenomenon is applied to optimize the volumetric efficiency of an engine converted into LPG-hydrogen blend. The effect of the intake plenum length on the engine performance is investigated. In fact, an analytical resolution of acoustic waves is used to perform the optimal length for several engine speeds. This resolution is based on the impedance method. In a second step, a simulation of the pressure wave evolution in the intake pipe is carried out using the method of characteristic in order to validate the lengths analytically found. After that, a validation is achieved through experimental data. The results showed that an optimum length calculated by the analytical method gives a maximum in-cylinder velocity (0.649 m at 750 rpm and 0.696 m at 1000 rpm). [ABSTRACT FROM AUTHOR]

This study develops a new type of heat exchanger with tungsten wires to produce a corona wind. Experimental data are presented for the velocity and temperature of the corona flow from wires to parallel electrodes with respect to the applied voltage and power. Additionally, a gas engine power generation system is manufactured, and its power generation efficiency is tested according to the fuel gas volume fraction between methane and carbon dioxide. Furthermore, an exhaust gas heat recovery system is fabricated using the proposed heat exchanger. A prototype of the corona wind heat exchanger is manufactured, and its enhanced heat recovery efficiency is tested with the gas engine. The corona wind heat exchanger operates well under the available exhaust gas conditions; it increases the temperature of 1 L/min water flow by 45 °C by recovering 2 kW of heat energy from the exhaust gas. The total power production efficiency was increased from 29% to 47%. The results confirm that the proposed corona wind heat exchanger can be applied to the gas engines to greatly enhance their heat recovery efficiency. [ABSTRACT FROM AUTHOR]

In this paper, a combined cooling, heating and power (CCHP) system has been designed under an electric charge supply strategy for a residential complex in Iran. The aim of this research is energy, exergy and economic analyses of the CCHP system with using different prime mover arrangements and presenting appropriate condition of its operation according to these viewpoints. For this purpose, three types of gas engine, diesel engine, and gas turbine as prime movers have been presented and analyzed separately and simultaneously at six different scenarios and the appropriate scenario has been proposed for the CCHP system. In addition, the performance of system has been estimated at various part load conditions. The system is modeled and simulated using thermodynamic and economic relationships by using a computer code in the MATLAB software. The results show that the CCHP system under the electricity supply strategy with the simultaneous combination of two prime movers has significant advantages over one of them. The CCHP efficiency with two prime movers increases up to 10% compared to that of a single prime mover as well as the exergy efficiency. Additionally, scenario 4 by combining the gas engine and diesel engine is selected as the best scenario. It has 87% energy efficiency, 62.8% exergy efficiency, and operating cost reduction of about 80%. Also, the payback period is 6.3 years by taking interest rate into account and 1.36 years regardless of it. [ABSTRACT FROM AUTHOR]

Liquefied natural gas (LNG) qualifies as sustainable and secure marine fuel that is reliable in supply. The international standards (IGF Code) and classification regulations have been aligned. First experiences in ship operations and design are now available. Initial reports from the practical ship operations show that the lack of knowledge and misjudgements of original equipment manufacturers (OEM's), suppliers, consulting services and flag state authorities have led to operational restrictions or expensive retrofitting. The aim of this paper is to illustrate first experiences and operating instructions using this new and different marine fuel; derive recommendations for instructions for education and training programmes at maritime colleges, universities and business partners; present action recommendations for future operational concepts. [ABSTRACT FROM AUTHOR]

In this work, the sliding wear behaviour of the hardfacing alloys Stellite®12 and Tribaloy®T400 during interaction with a CrMo-steel is investigated at elevated temperatures. These materials are typically used for gas exchange valves and seat rings in large bore gas engines where they are subjected to severe operating conditions. The clean combustion and a decreased oil flow towards the tribosystem valve spindle/seat ring in the natural gas-fuelled engines cause excessive wear when operating at high combustion pressures and elevated temperatures. Commonly employed Co-based alloys for the valve seating faces show a vast variation in their wear behaviour when the high tribological loads act directly on the contact surfaces which are not protected by any type of tribofilm. In order to understand the mechanisms under unlubricated and metal-to-metal contact situation, reciprocating pin-on-disc sliding wear tests were carried out at high temperatures for the two common material combinations, mentioned above. The effects of temperature, initial hardfacing roughness, microstructure, and hardness on the friction and wear response are investigated. The quantitative wear results in combination with microstructural and wear mechanism analysis provide the foundation for a phenomenological description of the wear behaviour. The tendency to form oxides has been found to be a decisive factor in terms of the severity of wear of the investigated hardfacings. Stellite®12 shows low surface oxidation at elevated temperatures whereas the intermetallic phases in Tribaloy®T400 oxidize significantly. [ABSTRACT FROM AUTHOR]

Ultra-small biomass gasification and power generation systems are a promising technology for disaster areas in developed countries and non-electrified rural areas of developing countries. The gasification characteristics of carbonized wood pellets and carbonized wood briquettes without or with 1 wt% sea salt were tested in a pilot-scale updraft fixed-bed gasifier. The results showed that the carbon balance during gasification was easily achieved, and most of the chlorine in the carbonized briquettes with sea salt remained in the residual char and fly ash after gasification. Inorganic chlorine in the solid fuel was transformed into organic chlorine combined with carbon matrix after heat treatment in the gasifier. Syngas with a low heating value higher than 4 MJ·m −3 could be continuously obtained when the system reached a stable condition, which enabled power generation using a gas engine. A combination of several secondary tar removal processes was adopted for the syngas purification. The tar content in the syngas after the gas cleaning for 425 °C-carbonized pellet, 425 °C-carbonized briquette, 475 °C-carbonized briquette, and 475 °C-carbonized briquette with sea salt was 0.98, 0.26, 1.4, and 0.2 g·Nm −3 , respectively. During the stable stage, 425 °C-carbonized pellet showed the highest cold gas efficiency (CGE) of 45.6% and carbon conversion efficiency (CCE) of 57.8%, respectively, with an equivalence ratio (ER) of 0.24. A lower carbonization temperature showed a higher CGE and CCE. The residual char and fly ash after gasification could be considered for reuse as feedstock to further improve the overall process efficiency. The maximum output power was 23 kW at an air flow rate of 40 Nm 3 /h during the gasification of carbonized pellets, and the corresponding overall power generation efficiency of the engine using the syngas was about 27.8%. For 475 °C carbonized briquette, the maximum output power was 18 kW at an air flow rate of 40 Nm 3 /h, and the corresponding overall power generation efficiency of the engine using the syngas was about 25.5%. [ABSTRACT FROM AUTHOR]

Using an enriched pre-chamber is an effective way to extend the lean limit, to reduce the nitrogen oxide emissions and to avoid abnormal combustion in spark ignition natural-gas engines. Enrichment injection in the pre-chamber of a spark ignition natural-gas engine determines the flow field and the fuel–air mixture formation quality in the pre-chamber and has a profound influence on the combustion performance of the engine. In order to study the characteristics of enrichment injection in the pre-chamber of a natural-gas engine, two-dimensional particle image velocimetry measurements and three-dimensional computational fluid dynamics calculations were carried out. The influence of the enrichment injection angle on the engine performance was investigated with the aid of a computational fluid dynamics simulation tool. The results indicate that a change in the enrichment injection angle directly affects the gas motion, the fuel–air mixture formation, the flame propagation and the formation of nitrogen oxides in the pre-chamber and further influences the penetration of the flame jets, the combustion temperature distribution and the formation of nitrogen oxides in the main chamber. There is an optimal injection angle for this research engine. Of the four injection angles that were investigated, an injection angle of 14° results in the lowest nitrogen oxide emissions. [ABSTRACT FROM AUTHOR]

To contribute to the economic viability of waste heat recovery systems application based on the organic Rankine cycle (ORC) under real operation condition of natural gas engines, this article presents a thermoeconomic optimization results using the particle swarm optimization (PSO) algorithm of a simple ORC (SORC), regenerative ORC (RORC), and double-stage ORC (DORC) integrated to a GE Jenbacher engine type 6, which have not been reported in the literature. Thermoeconomic modeling was proposed for the studied configurations to integrate the exergetic analysis with economic considerations, allowing to reduce the thermoeconomic indicators that most influence the cash flow of the project. The greatest opportunities for improvement were obtained for the DORC, where the results for maximizing net power allowed the maximum value of 99.52 kW, with 85% and 80% efficiencies in the pump and turbine, respectively, while the pinch point temperatures of the evaporator and condenser must be 35 and 16 °C. This study serves as a guide for future research focused on the thermoeconomic performance optimization of an ORC integrated into a natural gas engine.