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Copyright of Low-Carbon Chemistry & Chemical Engineering is the property of Low-Carbon Chemistry & Chemical Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Energy Policy Journal / Polityka Energetyczna is the property of Mineral & Energy Economy Research Institute of the Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Working fluid selection for closed-cycle turbo-refrigerators (CCTRs) for deep freezing, as a more fundamental topic, has not yet received careful consideration, leading to limitations in attempts to optimizing CCTR design in the early stages of cycle design. This paper proposed the working fluid selection criteria that to select the one leading to the lowest system weight and volume without compromising the system energy efficiency. Design criteria, such as specific speed and Reynolds number, and their dependence on fluid properties are introduced to ensure uncompromising-efficiency design of turbomachinery. Normalized heat transfer area of recuperator correlated with fluid properties is derived as the evaluation criterion for system weight and volume. Applying the proposed criteria, the comparison between potential pure gases shows the normalized heat transfer areas required for nitrogen, neon, and argon are 1, 1.54 and 2.18, respectively. Therefore, nitrogen among all pure gases has the greatest potential to reduce system weight and volume. The comparison among potential binary mixtures highlights the methane-nitrogen mixture with the molar mass of 24.1 g/mol which reduces the required heat transfer area by approximately 20 % compared to pure-nitrogen-based system and may reduce it by nearly up to 30 % for systems with larger cooling capacity levels.

Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With ever increasing fossil fuel price and growing demands in cutting emissions, waste heat recovery (WHR) appears as a promising pathway to improve propulsion system performance, which can be potentially achieved by incorporating a recuperator. This paper explores the advantages and potentiality of further recovering exhaust heat from recuperated turboshaft engine through the concept of organic Rankine cycle (ORC) to improve fuel economy and thermal efficiency. For the intended application, working fluid selection is conducted after systematic consideration of thermophysical properties, environmental impact, health and safety issues. Furthermore, parametric analysis is carried out from the viewpoint of thermodynamics, and the genetic algorithm is also employed to obtain the maximum net power output. Targeting the implicit coupling between recuperator effectiveness and ORC performance, the potential advantages of the combined engine-ORC system are comprehensively evaluated at different operational regimes. The influence of flight condition is also discussed through sensitivity simulations for different altitudes. Results reveal that the combination of the recuperated engine with ORC cycle operated using acetone generally offers the greatest benefits, significantly reducing specific fuel consumption by 46%–59 % relative to the baseline simple-cycle engine, depending on the availability of heat source. This analytical work contributes to provide valuable insights into WHR technologies in the aviation industry. • ORC is proposed to recover exhaust heat from turboshaft engine with a recuperator. • Working fluid selection procedure suitable for aeroengine is conceived and applied. • Parametric investigation is conducted and GA is employed for optimization. • System performance is comprehensively evaluated at different operational regimes. [ABSTRACT FROM AUTHOR]

The present research presents an innovative thermal integration model for a biomass-based power plant to generate power, coolant, and liquefied hydrogen. This integrated arrangement comprises biomass gasification, gas turbine cycle, organic flash-bi-evaporator refrigeration cycle, multi-effect desalination, solid oxide electrolyzer, and Claude cycle. The selection of an eco-friendly fluid for the electricity-cooling production cycle is conduced relying on a comparative analysis. The subsequent examination evaluates the economic-sustainability performance criteria through sensitivity and contour analyses. The comparative assessment identifies R1234ze(Z) as the most suitable working fluid. Four objective functions are scrutinized, and two optimization scenarios are devised based on a machine learning approach using artificial neural networks and a multi-objective gray wolf optimization technique. In Scenario A, the focused objectives are the total destructed exergy and the cost of producing liquefied hydrogen. Meanwhile, Scenario B integrates the sustainability index and the overall system cost rate as primary criteria. Scenario A exhibits more favorable operational conditions and outcomes than scenario B, showing the objectives mentioned as 9955 kW and 3.25 $/kg, respectively. In this scenario, the sustainability index, the overall investment cost rate, and the net present value are obtained to be 1.74, 236 $/h, and 205 M$, correspondingly. • Innovative biomass-driven system, producing power, coolant, and liquefied hydrogen. • Working fluid selection procedure for better eco-friendly integrated process. • Sustainability and economic evaluation/optimization using ANN-MOGWO-TOPSIS. • Scenario A is the suitable route, showing E ˙ D , tot at 9955 kW and c LH at 3.25 $/kg. • SI tot , Z ˙ tot , and NPV are found at 1.74, 236 $/h, and 205 M$, respectively. [ABSTRACT FROM AUTHOR]

This work addresses the multi-objective design of an organic Rankine cycle system for low-enthalpy applications. The design is generated from end-user demand variations. The model uses the reference equations of state of four working fluids commonly used in the literature: R1234yf, R1234ze (E), R134a and R245fa. This approach allows computing the optimal sizing of each unit of the equipment that composes the cycle, obtaining a suitable configuration for each working fluid. That is, the comparison between configurations is linked to the thermodynamic properties of the fluid. In addition, it addresses the phase changes present in each operation and the operational adjustments associated with changes in demand. Therefore, the optimal design captures partial load operation through a multi-period model. Given the off-grid operating conditions, the effects of coupling with energy storage systems are analyzed. The considered objective functions are the total annual cost and energy efficiency of the system. Results indicate that the sizing of the heat exchangers is significantly affected by phase change effects and that the R1234yf and R1234ze (E) fluids are promising since their thermodynamic properties allow for trade-offs between the economic and energy performance of the system. System efficiencies, considering part-load operation and demand variability, can be increased by up to 2 % with the inclusion of energy storage, significantly improving economic performance and reducing costs by up to 10 %. • A multi-objective NLP comprehensive model is used for sequential optimal design of ORC systems. • It is computed an optimal configuration according to the thermophysical properties of each fluid. • Size and pressure operation of turbine are identified as the core of efficiency performance. • Trade-offs for economic and energy efficiency performance are computed. • Working fluid selection should consider the configuration of the ORC. [ABSTRACT FROM AUTHOR]

To advance sustainable development and emission reduction efforts within the maritime industry, a novel combined cooling, heating, power, and storage (CCHPS) system is proposed. This system comprises a cogeneration system (ORC + ARC) and a thermal energy storage (TES) system. Initially, optimal working fluids are selected for the ORC and TES discharge systems. Subsequently, an analysis is conducted regarding the correlation between sensitivity parameters and system performance. Then, the cogeneration system's optimum design parameters are determined utilizing the multi-objective grey wolf optimization (MOGWO) algorithm. Finally, the TES system is analyzed and matched with the diesel generators to meet the ship's electricity demand. The CCHPS system achieves optimal thermal efficiency, payback period, annual CO 2 emission reduction, and annual fuel savings of 30.07%, 6.22 years, 8910.49 tons, and 2791.74 kL, respectively. In contrast to the TES-absent system, the CCHPS system exhibits a 12.88% increase in thermal efficiency, along with a 25.48% improvement in annual fuel savings and annual CO 2 emission reduction. [Display omitted] [ABSTRACT FROM AUTHOR]