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![Characteristics of the exhaust gases of the two engines as a function of the engine load [36].](publication/339974251/figure/tbl3/AS:870702915809282@1584603160310/Characteristics-of-the-exhaust-gases-of-the-two-engines-as-a-function-of-the-engine-load.png)
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When considering waste heat recovery systems for marine applications, which are estimated to be suitable to reduce the carbon dioxide emissions up to 20%, the use of organic Rankine cycle power systems has been proven to lead to higher savings compared to the traditional steam Rankine cycle. However, current methods to estimate the techno-economic...
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... water temperatures of 10 • C, 15 • C, and 20 • C were considered for the case studies. Table 3 reports the exhaust mass flow rate and temperature for the two engines as a function of the load. The data was retrieved from the MAN CEAS engine calculation tool [36]. ...Similar publications
This study presents a techno-economic assessment of Carnot batteries for load-shifting of solar PV production of an office building considering variable electricity production, demand and pricing. The building has an annual electricity demand of 2600 MWh and a maximum power demand of 0.564 MW. The Carnot battery studied is based on a subcritical Ra...
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... In the next sections, another technology for waste heat recovery from gas turbines, i.e. the organic Rankine cycle as investigated by Carcasci et al. [35], is considered for technology comparisons. Without proposing specific detailed calculations, the ORC technology cost for next comparisons is readily calculated according to SC ORC ¼ 19358,P À0:2703 el (13) as proposed by Baldasso et al. [36] who recently retrieved the cost estimations reported by Lemmens [37]. The specific cost of the ORC technology in Eq. (13) is calculated as $$kW À1 and P el is the net electric power production in kW. ...
Supercritical CO2 (sCO2) cycles represent an innovative technology especially if applied for waste heat recovery from gas turbines. This work investigates the performance of the partial heating sCO2 cycle as the bottoming cycle of a 5 MW-class gas turbine. Particular attention is paid to the selection of both minimum CO2 pressure and temperature and use of the non-dimensional criterion named Acceleration Margin to Condensation is made to prevent the formation of liquid CO2 droplets at the inlet of the compressor. Moreover, in order to avoid heavily loaded turbomachinery, considerations about the machine Mach numbers result in possible limits for the maximum cycle pressure. Single-stage radial turbomachines are selected and their efficiency calculated according to Aungier's correlations by taking actual size and running conditions into account. Focusing on the net electric power produced by the bottoming cycle and on the corresponding specific cost, a number of investigations has been carried out. After setting a limit for the compressor Mach number, around 1600 kW can be recovered by the sCO2 bottoming cycle, though a techno-economic optimization would guide towards an optimum point with slightly more than 1500 kW of power output and a specific cost for the technology of around 2000 $/kW.
... In particular, the specific cost for the ORC technology is calculated as. (11) according to Baldasso et al. [56] who retrieved the cost estimations reported by Lemmens [57]. The specific cost in Eq. (11) is calculated as $⋅kW − 1 and P el is the net electric power production in kW. ...
... Around 1500 kW of net electric power can be recovered by the investigated bottoming cycle, with a specific cost of the technology of around 2000 $/kW. In detail, the last figure is lower compared to the specific cost of the organic Rankine cycle [56,57], as a possible competing solution for waste heat recovery applications, and highlights the potential of the sCO 2 power cycle technology. ...
Among the technological solutions that can be applied to waste heat recovery, the supercritical CO2 (sCO2) cycle represents an innovative option. This work studies the performance of the single heated cascade sCO2 cycle as the bottomer power system of a 5 MW-class gas turbine and follows a former study of the authors about the partial heating cycle. A number of parametric analyses has been carried out with attention paid to the selection of (i) minimum and maximum CO2 pressures, based on a compressor Mach number selected to avoid highly loaded turbomachinery, (ii) maximum CO2 temperature, and (iii) specific design parameters such as temperature difference at the cold side of the primary heater, recuperator effectiveness and single-stage radial-type turbine efficiency, the latter calculated according to Aungier’s correlations by taking actual size and running conditions into account. The results of this study suggest that around 1500 kW of net electric power can be recovered by the single heated cascade sCO2 cycle. This figure is not so different from the power output previously calculated for the preheating cycle as well as the specific cost of the technology, which is around 2000 $/kW, lower than a possible competing technology for waste heat recovery applications as the organic Rankine cycle. Nevertheless, the architecture investigated in this study needs two turbines which can rotate on the same shaft, but driving the compressor at the same rotational speed of the two turbines is not possible, as emerges from preliminary considerations about the size of the turbomachinery impellers.
... Cost correlations for sCO2 power cycles originally proposed by Wright et al.[5].Based on the component costs, a specific figure in $ꞏkW el -1 results for each sCO 2 bottoming cycle calculation. A comparison with a competing technology, namely the organic Rankine cycle (ORC), formerly investigated by Carcasci et al.[20] as a suitable solution for waste heat recovery from gas turbines, is made according to the specific cost suggested by Baldasso et al.[21]:� 19358 • �0.2703 ...
This work investigates the performance of a supercritical CO 2 cycle as the bottoming cycle of a commercial gas turbine with 4.7 MW of electric power output. In detail, the partial heating cycle is the layout chosen for the interesting trade-off between heat recovery and cycle efficiency with a limited number of components. Single-stage radial turbomachines are selected according to the theory of similitude. In particular, the compressor is a troublesome turbomachine as it works near the critical point where significant variations of the CO 2 properties occur. Efficiency values for turbomachinery are not fixed at first glance but result from actual size and running conditions, based on flow rates, enthalpy variations as well as rotational speeds. In addition, a limit is set for the machine Mach numbers in order to avoid heavily loaded turbomachinery. The thermodynamic study of the bottoming cycle is carried out by means of the mass and energy balance equations. A parametric analysis is carried out with particular attention to a number of specific parameters. Considering the power output calculated for the supercritical CO 2 cycle, economic calculations are also carried out and the related costs compared to those specific of organic Rankine cycles with similar power output.
... This book contains the successful invited submissions [1][2][3][4][5][6][7][8][9] to a Special Issue of Energies entitled "Organic Rankine Cycle for Energy Recovery System", focusing on a modern technology committed to energy saving and thus capable of producing positive environmental outcomes. Indeed, the organic Rankine cycle (ORC) is a thermodynamic concept already demonstrated as an engineering viable solution for waste heat recovery systems. ...
... • Branchini et al. [4] analyse, in their paper, the ORC design and off-design performance in a WHR combined heat and power annual production scenario; the study offers a thermodynamic and economic parametric comparison of different most common fluids and layout options; the study also shows that the ORC application to existing CHP energy systems can be implemented, obtaining improved energy savings. • Baldasso et al. [5] consider the potential of ORC on board of ships; a simplified method based on a set of precalculated regression curves of ORC performance is introduced to assess the techno-economic feasibility of the waste heat recovery applied to the engine of the ship. • A representative example of an ORC plant integrated with a biomass boiler is provided by Stoppato et al. [6], where the main focus is on the LCA technique application and the calculation of carbon footprint. ...
This book contains the successful invited submissions [...]
... Analysis and assessment studies can act as monitoring tools to determine the current performance quantitatively for comparison between alternatives and identify possible improvements in design. Life cycle assessment (LCA) based on environmental impacts or environmental footprints [47] and techno-economic assessment [74] are among the common approaches. Khoshnevisan et al. [75] performed a consequential life cycle assessment to compare the conversion of the organic fraction of municipal solid waste to bioenergy and high-value bioproducts (e.g., microbial protein, lactic, and succinic acid). ...
Energy is a fundamental element supporting societal development, particularly with the increasing dependency on the Internet of Things. It is also the main contributor to environmental impacts and subsequently, a potential sector for mitigation. Sustainable energy system design considers energy savings and energy efficiency, waste and consumption reduction, process efficiency enhancement, waste heat recovery, and integration of renewable energy. Emerging tools range from advanced Process Integration, modelling, simulation, and optimisation, to system analysis and assessment. This review covers selected emerging studies promoting sustainable system design, including the recent developments reported in the Special Issue (SI) of the 22nd Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction (PRES’19). The primary emphasis was to enhance the economic and environmental performance. However, social factors were also highlighted as essential for future sustainable development. The discussion and analysis in this review focus on the most recent developments of (a) heat integration and heat transfer; (b) integrated and newly developed heat exchangers, (c) integration of renewables, and (d) roles in economic and environmental sustainability. The key results are highlighted, and future research ideas are suggested according to their links to a broader context.
... Previous studies addressing the optimal design of ORC units for marine applications focused on the identification of the most suitable working fluid [7], on the optimization of the unit's design given the ship sailing profile [8], on ensuring stable operation of the unit through the use of optimized control strategies [9], and on the definition of methods to carry out preliminary evaluations of the techno-economic feasibility of the installation [10]. ...
The installation of an organic Rankine cycle unit on the exhaust line of a marine engine imposes an increase in the backpressure on the engine, resulting in a decrease of the engine performance and a variation of the available waste heat. In this paper, a method is presented for the optimal design of organic Rankine cycle power systems for waste heat recovery in marine applications. The method is based on the use of performance maps for the engine and numerical models for the organic Rankine cycle unit and the waste heat recovery boiler, thereby enabling consideration of the effect of the increased backpressure on the performance of both the main engine and the organic Rankine cycle unit. The method is evaluated on a hypothetical containership fuelled by liquefied natural gas. The results of the study indicate that the overall system fuel consumption can be reduced by 0.52 g/kWh to 1.45 g/kWh by allowing higher backpressure levels on the engine. In addition, the results of the study indicate that for a fixed power output of the organic Rankine cycle unit, a reduction of the space requirement for the waste heat recovery boiler by up to 35 % can be attained when increasing the maximum allowed engine backpressure from 3 kPa to 6 kPa.
In the global effort to reduce Green House Gases and carbon emissions, there is great importance for the shipping industry to decarbonise and move forward into a greener future. However, there is a lack of academic commentary on how attempts at various decarbonisation methods reported in research articles have developed over the 21st century, particularly in line with the relevant policy and regulatory developments. This paper analyses how the shipping industry has decarbonised by utilising 294 papers from 2000 to 2020. By analysing 20 years’ worth of research, this paper delivers a comprehensive review of shipping decarbonisation research and analyses the evolution of its themes as a function of time. It therefore aids to develop a greater understanding and comparison of governmental, economic and academic perspectives (and their potential alignment) for the industry to decarbonise. For 2017–20 the key shipping decarbonisation technologies were summarised and their advantages, disadvantages and current academic literature applications are revealed. Furthermore, the analysis of the evolution of shipping decarbonisation research themes reveals clear research gaps in the current literature and guides the development of a future research agenda with the prediction of future opportunities and potential for shipping decarbonisation research developments for the shipping industry.
The problem that the exact nonlinear connection between fluids flow and heat transfer in direct contact heat evaporator was studied. The direct contact heat evaporator structure can be optimized and direct contact heat transfer process can be improved with the help of the optimum matching relationship between the complex flow and heat transfer. The methods used are the signal processing technology (i.e., empirical mode decomposition) and the machine learning algorithm (i.e., least squares support vector machine) for calculating experimental heat transfer coefficient here. The important specific and quantitative results are that the volumetric heat transfer coefficient prediction accuracy can be improved by the proposed the hybrid model. When empirical mode decomposition is combined with least squares support vector machine, the accuracy of the hybrid model can be improved by 20% without and 62% with the influencing factors. The conclusions that can be drawn from the results are two-fold. The optimal matching relationship between internal flow characteristics and heat transfer performance can be understood in direct contact heat transfer system for waste heat utilization. The hybrid model can improve the prediction accuracy and efficiency, reduce the number of experiments and costs, save raw materials and shorten the design cycle. Hence, the novelty of the work is that a new hybrid model is proposed for predicting VHTC. The gap it filled in the literature is that the prediction of volumetric heat transfer performance during direct contact heat transfer process is considered. In addition, it is carried out in a highly accurate and highly efficient way using this proposed model.
