Thermo

This study integrates a Radial Basis Function Neural Network (RBFNN) with Adaptive Dynamic Programming (ADP) to develop an Action-Dependent Heuristic Dynamic Programming (ADHDP) framework for the cost-effective control of an Ice Storage Air-Conditioning (IAC) system. The proposed approach aims to establish a self-learning control strategy for reducing the overall operating cost of the system. In this study, the operational states of the air-conditioning system and the ice-storage/release states of the ice-storage tank are selected as the control variables. To approximate the nonlinear cost-to-go function of the IAC scheduling problem, an RBFNN is employed as the critic-network function approximator. Its local nonlinear approximation capability enables the controller to evaluate the long-term operating costs associated with different ice-storage, ice-melting, and air-conditioning actions. As a result, the proposed ADHDP method can evaluate feasible operating actions and select the action associated with the minimum estimated cost-to-go. Furthermore, an actual IAC system is adopted as the research subject. Field operational data are collected and utilized for system modeling and analysis. Simulations are conducted to compare the Conventional Control Strategy (CCS), ADP, and the ADHDP approach, with operating cost serving as the primary evaluation index. For the investigated representative operating scenario, ADHDP achieved operating costs approximately 7.24% and 1.66% lower than CCS and ADP, respectively. These values represent case-study results under the specific operating conditions considered in this study. Moreover, the ADHDP framework exhibits stronger adaptability to varying cooling loads and electricity pricing conditions, thereby improving the operational efficiency and energy management capability of the IAC system.

Buildings account for roughly 37% of energy-related CO2 emissions, and space cooling already consumes nearly 10% of global electricity. Cooling demand is rising fastest in tropical cities, where air-conditioning could reach 45% of peak load, especially in India by 2050. This review critically examines thermal energy storage (TES) as a flexibility resource across three distinct scales: individual buildings, district heating and cooling networks, and city-level multi-energy systems. Using a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-based search of Scopus, Web of Science, and IEEE Xplore with primary and supplementary strings, 4447 records were identified, of which 174 were included. Each quantitative study was classified by validation level (simulation, laboratory, pilot, or operational) and by the centrality of thermal storage. Sensible, latent, and thermochemical storage technologies are compared using energy density (10–500 kWh/m3), efficiency (40–95%), cycle stability, and technology readiness. The review then evaluates the role of artificial intelligence (AI), machine learning, and Internet of Things platforms in forecasting, predictive control, and operational optimization of TES networks. Thirteen method families, grouped into AI and machine learning methods, optimization methods, control methods, and digital enabling technologies, are assessed against six explicitly defined criteria with evidence-coded scores. Among 47 quantitative studies, 37 (78.7%) are simulation-only, and only four (8.5%) report operational data. Direct TES-AI studies report simulated energy savings of 8–64% and peak load reductions of about 35%, whereas field-validated intelligent control reports 17% energy savings in a single real building experiment. The review also identifies inherent drawbacks of artificial intelligence-based operations, including limited interpretability, high data and computational demands, concept drift, and cyber vulnerabilities that increased peak electric load by 17.4% in a simulated attack. A structural imbalance in the literature is evident: most validated deployments remain at the building-scale, whereas urban-scale evidence is confined to district cooling, aquifer and pit storage, and multi-energy hub studies; no study reports the coordinated operation of distributed TES assets across multiple districts. A conceptual framework and a staged roadmap linking building, district, and urban scales are proposed. Priority research needs include urban-scale pilots in tropical climates, techno-economic assessment, interpretable and drift-robust AI, and interoperability standards that support United Nations’ Sustainable Development Goals 7, 11, and 13.

In this work, the effect of mechanical activation (MA) on the double complex salt (DCS) [Co(NH3)6][Fe(C2O4)3]·3H2O and its thermolysis is investigated. Mechanical activation is a promising “green chemistry” method that allows improving the physicochemical properties of the DCS [Co(NH3)6][Fe(C2O4)3]·3H2O and the products of its thermal decomposition in an argon atmosphere. The conditions of the MA process and the effect of MA and passivation on the process and kinetics of DCS thermal degradation were investigated. It was shown that due to the removal of outer-sphere coordinated water and carbonation of the DCS during MA, the number of thermal degradation stages changes. It was established that passivation at 450 °C for MA times of 0 and 10 min prevents spontaneous “combustion” of the thermal degradation products of the DCS. Optimal conditions for DCS processing were determined to be 5 min of MA and heat treatment at 450 °C without passivation. Under these conditions, the yield of the CoFe intermetallic compound reaches 82.6 wt%. This optimal combination of sample production conditions allows for a reduction in MA time and the elimination of the passivation process, making the process more cost-effective and creating conditions for optimizing the production of functional materials.

Pyrolysis is a leading route for valorizing lignocellulosic residues, yet detailed multi-step kinetic schemes have so far been deployed only in costly commercial simulators, limiting reproducibility. This work couples thermogravimetric (TGA) characterization with process simulation in the free, open-source simulator DWSIM to predict the pyrolysis product distribution of corn cob from Córdoba, Colombia. The lignocellulosic composition (hemicellulose 24.3 ± 2.9, cellulose 36.4 ± 3.0, lignin 39.3 ± 0.9 wt%) was obtained by deconvolving the derivative thermogravimetric (DTG) curve with a five-parameter asymmetric double sigmoidal (Asym2sig) function (R2 > 0.9996). Pseudocomponent activation energies from the Coats–Redfern method (154.2, 124.6, and 29.9 kJ/mol) calibrated the primary reactions of a 17-reaction Ranzi scheme, extended with 18 secondary gas-phase steam reforming reactions. Validated against eight lignocellulosic biomasses, the calibrated model yielded a consolidated R2 = 0.853 and average absolute deviation (AAD) = 9.8%, with char predictions most accurate (AAD = 8.9%). For corn cob, a bio-oil-optimized yield of 55.0 wt% was predicted at 500 °C, transitioning to a syngas-rich regime (51.0 wt% gas) at 750 °C. This constitutes the calibrated Ranzi-scheme implementation in DWSIM, offering an accessible, reproducible pathway for biomass pyrolysis modeling.

This study presents a transient two-dimensional model devised to predict frost build-up, pressure drop, and sensible and latent heat transfer rates in tube-fin evaporators, commonly used in ‘frost-free’ refrigerators. Based on the first principles of mass, momentum, and energy conservation for the airflow and the frost layer, the model accurately simulates evaporator blockage over time. Furthermore, it incorporates the interaction between the heat exchanger air-side impedance and the fan performance characteristic curve, using an iterative fluid-dynamic sub-model that predicts airflow reduction and redistribution in an evaporator with three fin densities. Frost accretion experiments were conducted using a purpose-built test setup consisting of a bottom-mount refrigerator cabinet maintained at controlled temperature and humidity in both the fresh and frozen-food compartments. Model validation demonstrated that the predicted results closely matched experimental observations. The results show that localized frost accumulation at fin density transitions causes severe airflow blockage, resulting in a 75% reduction in effective heat transfer area due to uneven air distribution. Finally, an analysis of two dimensionless competing indices demonstrates that fin density selection involves a critical trade-off between the initial cooling capacity and long-term frost resilience.

Additive Manufacturing (AM) for jewelry applications is increasingly adopting Binder Jetting (BJ) to overcome the fusion-related limitations associated with precious metals, including unstable melt pools, excessive reflectivity, and high thermal conductivity. In this context, the present review establishes a thermophysical and manufacturability-oriented framework that redefines thermal management beyond localized melt-pool stabilization toward the furnace-scale control of densification kinetics, shrinkage evolution, atmosphere-assisted sintering, and viscoplastic deformation. Particular emphasis is placed on gold-, silver-, and platinum-based jewelry alloys, with a specific focus on the thermal, mechanical, and chemical phenomena governing Binder Jetting sintering. During consolidation, low-density green bodies (~40–65% relative density) must transform into highly dense components through extensive volumetric shrinkage and gravity-driven deformation, creating major challenges in dimensional fidelity and surface quality. The review further examines predictive viscoplastic constitutive models (SOVS/ROH), reversed-deformation compensation strategies, and atmosphere-engineering approaches for oxide reduction, pore-pressure regulation, and residual-porosity control. By linking thermophysical consolidation, dimensional fidelity, polishability, and jewelry-grade manufacturability within a hierarchical framework, this review provides a structured basis for the development of high-precision and low-waste precious-metal additive manufacturing.

This experimental study investigates the performance and sustainability of a modified double-slope solar still (MDSSS) integrated with a combined water channel to enhance evaporation rates. The integration of the water channel ensures uniform water flow and enhanced heat distribution across the basin surface, thereby improving thermal performance. Experiments were conducted using three types of feed water, groundwater, saline water, and domestic wastewater, to assess the system’s versatility and effectiveness in various water desalination applications. Under identical meteorological conditions, thermal parameters, distillate yield, energy efficiency, and sustainability were analyzed. The results revealed that incorporating the water channel significantly increased evaporation and condensation rates compared to the conventional double-slope solar still (DSSS) configuration. Also, the performance of an MDSSS was evaluated under various water qualities, including physical, chemical, and biological parameters. The experiment begins at half the optimal water depth for water quality, with the remaining half passing through an open-channel attachment into the solar still basin. The modified system effectively reduced pollutants, achieving a 98.18% reduction in chemical oxygen demand in groundwater, complete salt removal from saline water, and a 96.67% reduction in sewage water.

Ventilated façades are increasingly used in building renovations, often containing non-renewable and CO2-emissions-intensive cement-based materials. Renewable biomass-based materials offer a more sustainable alternative with a high amount of sequestered CO2. However, water uptake is a critical factor in exterior applications. This study investigates the water resistance of high-density particleboards made of wheat straw (WS), grey alder (GA), and softwood (SW) for façade-related exterior applications. Two general board types were produced from each biomass using (1) steam explosion (SE) treatment and (2) the addition of birch-bark-derived suberinic acids (SAs) as the bio-based binder. In addition, the influence of conventional and mold hot pressing was investigated. The particleboards were coated with four types of innovative finishes, comprising (1) purified SA, (2) SA + chitosan (SH), (3) SA + earth pigment (SP), and (4) SHP. The water resistance of the particleboards was evaluated using an internal bonding (IB) test after 2 h of boiling and by measuring the water drop contact angle. FTIR analysis was performed to identify differences between the board varieties and to explain the obtained results. Only two board varieties (GASA and SWSA) fulfilled the Type P5 EN 312 water resistance requirement (0.15 N/mm2), achieving IB values of 0.81 ± 0.23 N/mm2 and 0.22 ± 0.07 N/mm2, respectively. In turn, the coatings used did not significantly increase the static contact angle compared to the reference board. Although the results of this study confirm the inherent moisture sensitivity of engineered particleboards, two board varieties demonstrate promising potential for façade-related exterior applications.

This study addresses the energy demand profiles of commercial buildings by developing an optimal dispatch strategy for a regional high-efficiency distributed energy system integrating electricity, cooling, and storage through source–load coordination. The spatiotemporal distribution characteristics of cooling, heating, and electrical loads are analyzed and an integrated energy system model is established, comprising gas internal combustion engine, a lithium bromide absorption chiller/heater, gas-fired boiler, centrifugal chillers, and an ice storage system. Taking into account seasonal electricity pricing policies and meteorological variations in Shanghai, a load grading system and a time-of-use (TOU) pricing response mechanism are constructed, leading to the development of operational strategy portfolios for different typical scenarios. A multi-objective optimization dispatch model is formulated with the dual aims of minimizing operating costs and maximizing energy efficiency. The results indicate that, compared to a fixed operational mode, the optimized strategy achieves average CO2 emission reduction rates of 16.4% in summer, 25.2% in non-summer periods, and 20.9% annually. Additionally, annual grid electricity purchases are reduced by 10.2%, with a static investment payback period of 11.37 years. This research provides an intelligent, practically applicable operational solution for distributed energy systems in commercial buildings, effectively overcoming the limitations of traditional approaches in terms of flexibility and economic performance.

Conventional continuum thermodynamics is characterized by a classical form of the energy law and the second law of thermodynamics in the form of the Clausius–Duhem inequality. This thermodynamic framework fails to capture certain features in material response as, e.g., length scale effects, temperature waves in rigid heat conductors and diffusion phenomena. Typically, such material characteristics are associated with pronounced non-localities in time and space. To tackle these issues, non-conventional thermodynamic approaches might be appropriate. The employment of non-conventional thermodynamics is very attractive, as it enables the extension of the applicability of conventional thermodynamics in a simple way. A specific non-conventional thermodynamic framework has previously been proposed as a generalization of irreversible thermodynamics. Energy supply effects were neglected in this work. However, energy supply terms may become important when discussing thermodynamical consistency of many physical models. The present paper extends the applicability of the proposed non-conventional thermodynamic framework by accounting for energy supply densities and demonstrates its capabilities by addressing Cattaneo’s heat conduction law—known for predicting temperature waves—and thermo-diffusion coupling theories. It is shown that, within the adopted thermodynamics, the considered physical models are thermodynamically consistent and that the resulting field theories admit formulations within a variational framework for rate problems; in this sense, the models are properly formulated.

Thermal energy storage plays a crucial role in meeting human energy demands and is particularly essential for many solar energy applications. Among the various storage methods, phase change materials (PCMs) have attracted significant attention because their thermal performance can be greatly influenced by the material properties, physical characteristics, and the geometry of the encapsulating container. In this paper, the melting process of phase change materials (PCMs) within an elliptical enclosure using the finite volume method is analyzed. Gallium is selected as a PCM with a low Prandtl number. A physical model employing the enthalpy porosity formulation is elaborated to describe the coupling between natural convection and the melting process of PCMs. Numerical simulations are performed to examine the influence of the aspect ratio (n = b/a), ranging from 1 to 4, and inclination angles from 0° to 90° of the elliptical enclosure on the melting process. It has been found that the use of the elliptical capsule can reduce the melting process time. For a Rayleigh number of 106, the melting time decreases as the aspect ratio increases from 1 (circle) to 4. The horizontal orientation (θ = 0°) is found to be the most efficient, with a melting rate higher than that observed for inclined positions (30°, 45°, 60°, and 90°). For a low Rayleigh number of 104, the inclination angle has an imperceptible effect on the phase change. Empirical correlations are proposed to relate the Nusselt number to the Rayleigh number, with coefficients adapted to different Fourier numbers and geometric parameters.

An experimental setup has been developed that enables the conversion of a complex stream of polydisperse droplets generated by an ultrasonic dispenser into a stream of nearly identical droplets falling through a vertical channel. The fall of droplets of an aqueous NaCl solution in this channel, filled with heated dry air, is studied. Water from the droplets evaporates quickly, and crystals of a solid salt crust form on their surface. At a later stage of the process, the remaining solution is removed from the droplet using a jet of water vapor that passes through the pores of the polycrystalline crust. It was first observed that some of the drying droplets suddenly shifted to one side under the influence of the reactive force generated by the vapor jet. Images obtained using a scanning electron microscope show that the salt particles formed have a diameter of around 25 µm, are slightly porous, and consist of numerous crystals. It has been proven that these particles do not have a central cavity. The use of seawater and the role of salt particles in protecting against thermal radiation from fires are briefly discussed. Calculations based on Mie theory have shown that the contribution of light scattering by thin-walled hollow sea salt particles formed above the ocean surface during relatively slow evaporation of seawater droplets can be significant to the ocean’s heat balance.

The present paper is motivated by challenges in the design of the surface insulation in borehole thermal energy storage (BTES). A case study of a BTES with nine borehole heat exchangers (BHEs) in a cold climate is considered. Transient numerical modeling of the storage charging phase is performed by solving the three-dimensional heat equation using the finite difference method. Heat conduction through the insulation cover is simulated in accordance with Fourier’s law. A parametric study is conducted with respect to the prescribed heating setpoint temperatures in the BHEs and to the geometry of the insulation cover. The thermal analysis shows that the efficiency of the storage volume is strongly dependent on the heat transfer through the upper boundary. The insulation layer affects the minimum temperature reached within the BTES, with the influence of insulation thickness being most pronounced at thicknesses up to 10 cm. Furthermore, it is demonstrated that the lateral extension of the insulation cover has a greater impact on storage capacity gains than increasing its thickness, and that these energy gains expand progressively over time. Under cold ambient conditions, effective seasonal storage requires managing sharp ambient thermal gradients via a wider peripheral coverage of the insulation layer to offset vertical conductive losses.

The increasing demand for higher efficiency and lower emissions in aircraft gas turbines motivates investigation of alternative thermodynamic cycle architectures. This study assesses the performance and nitrogen oxides (NOx) emission behavior of a triple-spool, separate-exhaust turbofan engine equipped with an interstage turbine burner (ITB). A baseline engine representative of the RB211 Trent 892 is first modeled at maximum takeoff, sea-level static conditions and verified against publicly available takeoff reference data. The cycle is then modified by introducing an isobaric secondary combustion process between the high-pressure and intermediate-pressure turbines. The effects of fan pressure ratio, bypass ratio, overall pressure ratio, high-pressure turbine inlet temperature, and ITB exit temperature are examined using two-parameter response surface sweeps. Main combustor NOx is estimated using an RQL-type cycle correlation, while the ITB contribution is represented using an engineering source–sink model accounting for new NOx formation and partial reburning of upstream NOx. The baseline model predicts specific thrust, thrust-specific fuel consumption (TSFC), and NOx emission index (EINOx) within ±8% of reference values. At a selected ITB operating point, specific thrust increases by 1.98%, TSFC increases by 9.84%, thermal efficiency decreases by 2.56%, and the adopted engineering source–sink model predicts a 20.03% reduction in fuel flow-weighted EINOx. The corresponding takeoff-mode NOx-per-thrust indicator decreases by approximately 12.1%. These results indicate that ITB integration introduces a coupled performance–emissions trade-off and should not be evaluated solely as a thrust augmentation method.

This study investigates the coupling between flow dynamics, acoustic response, and convective heat transfer in a rectangular impinging jet striking on a heated slotted plate at two closely spaced Reynolds numbers (Re = 3550 and Re = 3750). Velocity fields were obtained using Particle Image Velocimetry (PIV), and coherent structures were analyzed using Proper Orthogonal Decomposition (POD) while acoustic measurements were used to characterize the tonal behavior. Infrared thermography was employed to determine local and mean Stanton numbers. The mean Stanton number increased by 6.6% when the Reynolds number increased from Re = 3550 to Re = 3750, while the sound pressure level decreased from 78 dB to 71 dB. At Re = 3550, the acoustic spectrum exhibited multi-tone behavior associated with distributed modal energy. In contrast, at Re = 3750, a single dominant frequency governed the flow dynamics. The energy of the first POD mode nearly doubled when passing from Re = 3550 to Re = 3750. The cross-correlation coefficients between the first POD mode and the acoustic field increase from 0.76 to 0.93 when changing from Re = 3550 to Re = 3750. These findings show that the dominant vortex mode which contains nearly 20% of the fluctuating energy (for Re = 3750), significant influences the energy transfer from the dynamic field to the acoustic field resulting in a strong noise reduction. Simultaneously, convective heat transfer increases, highlighting the key role of coherent flow organization on both acoustic and thermal behavior of the system.

This study presents an experimental performance evaluation of an oil-based indirect solar fryer system designed for injera baking. The system consists of a receiver vessel, a closed-loop delivery and return pipe network, and a 60 cm diameter aluminum baking plate with spiral grooves on its bottom surface. Heat transfer oil circulates within the closed loop to transfer thermal energy from the receiver to the baking plate. The system was experimentally investigated under controlled electrical heating conditions using input power levels of 1.0, 1.3, 1.6, 1.75, 2.0, and 2.4 kW, representing equivalent solar thermal input scenarios with varying intensity. The results confirmed the technical feasibility of the system for injera baking across all tested conditions, with performance strongly dependent on input power. At higher input levels (≥2.0 kW), faster heating and shorter baking cycles of approximately 2.5–3 min were achieved; however, increased oil temperatures and thermal instability were observed due to limited heat redistribution within the fixed low-flow circulation system. At lower input levels (≤1.3 kW), the system remained thermally stable but exhibited long initial heating times (up to approximately 85 min) and reduced operational efficiency, limiting its practical applicability. The most balanced performance was observed at intermediate input power levels of 1.6–1.75 kW, where the system achieved approximately 45–60 min initial heating time, stable temperature behavior during operation, and consistent baking cycles of about 3 min with 1 min reheating time. This range provided an optimal compromise between thermal efficiency, operational stability, and energy utilization under the present configuration. Overall, the study demonstrates that the indirect solar fryer system is a promising alternative for energy-efficient injera baking; however, performance is strongly influenced by thermal input and circulation conditions, highlighting the need for further optimization and validation under real solar operating environments.

This study investigates steady-state conductive heat transfer and water-vapor diffusion through the external wall of a refrigerated warehouse with a specified load-bearing wall assembly. The formal analogy between heat conduction and mass diffusion is stated and used to establish a practical calculation framework for estimating heat and moisture ingress through multilayer cold-store walls. Calculation routines are presented to determine the temperature field and the corresponding water-vapor saturation and partial-pressure distributions across (and within) the insulation layer, enabling the identification of regions prone to interstitial condensation. The analysis highlights the roles of (i) the vapor diffusion resistance of the vapor barrier layer, (ii) the thermal resistance of the insulation, and (iii) key outdoor boundary conditions in governing condensation risk. Increasing insulation thermal resistance reduces external heat gains; however, it may also increase the likelihood of condensation in layers close to the cold side by lowering local temperatures and saturation pressures. Among external parameters, outdoor relative humidity exerts the strongest influence on interstitial condensation risk. For the investigated wall assembly, increasing outdoor relative humidity by 50% shifts the condensation onset location within the insulation toward mid-thickness. The effects of vapor barrier diffusion resistance, insulation thermal resistance, and changes in outdoor conditions (relative humidity, temperature, and wind speed) are reported in tabulated form and illustrated through pressure–position and temperature–position profiles.

Electrohydrodynamic effects can significantly alter transport processes in reacting flows, even when the plasma is weakly ionized. However, predictive modeling of such plasma–flame interactions remains challenging due to the multiscale coupling among charge transport, fluid motion, and chemical kinetics. This study presents a charge-transport closure model to investigate electrohydrodynamic influences on laminar non-premixed flames. A two-dimensional computational framework in cylindrical coordinates is used to simulate plasma-assisted methane–air diffusion flames under weak electric-field conditions representative of practical combustion environments. To represent plasma–flow coupling in a computationally feasible yet physically consistent manner, a charge-transport formulation based on the drift–diffusion approximation is employed. The model solves transport equations for representative positive and negative charge carriers coupled with Poisson’s equation for the electric potential to obtain a self-consistent electric field. This formulation assumes a weakly ionized regime for low-temperature plasma-assisted combustion, in which neutral species dominate the mass and momentum transport, while ionization chemistry is simplified and charge transport primarily influences the flow through electrohydrodynamic body forces and Joule heating. Assuming a weak electric field, the steady flamelet model is applied, in which plasma effects primarily influence scalar transport and local thermal balance rather than inducing significant bulk ionization dynamics. The governing equations are discretized using a high-order compact finite-difference scheme that provides improved resolution of steep gradients in temperature, species concentration, and space-charge density near thin reaction zones. The canonical laminar flame model configuration was validated using the established laminar methane–air diffusion flame benchmark, and steady-state spatial profiles of key transport properties were evaluated. Two-dimensional analysis identified the discharge coupling location as an important factor. The application of discharge in the fuel-air mixing region leads to a clear restructuring of the flame. When the discharge is activated, electrohydrodynamic forcing and ion-driven momentum transfer produce a highly localized, columnar flame with sharp gradients and a confined reaction zone. Compared with the baseline case, the plasma-assisted flame localizes the OH-rich reaction zone, confines the high-temperature region into a narrow column, and enhances downstream H2O formation.

This paper investigates the energy recovery potential of LNG cold energy using cryogenic binary cycles. The thermoeconomic performance of single-, two- and three-stage Organic Rankine Cycle (ORC) configurations across different working fluids and LNG regasification capacities has been evaluated. The analysis shows that ORC-based LNG cold energy power units achieve specific net power outputs of 45–55 kW/(kgLNG/s) for single-stage, 74–83 kW/(kgLNG/s) for two-stage, and 79–88 kW/(kgLNG/s) for three-stage configurations. The corresponding net energy efficiencies are 6.6–7.5%, 10.1–11.2% and 10.8–12.0%, respectively, while the exergy efficiencies are 15.9–17.6%, 22.9–25.3%, and 24.3–26.8%, respectively. Two-stage systems achieve the lowest costs: a levelized cost of electricity (LCOE) of 80–105 €/MWh and a specific investment cost (SIC) of 6000–8300 €/kW. For most of the evaluated working fluids, the power gain from a third stage does not justify the increase in equipment costs. Among the evaluated working fluids, R32, R41 and R161 achieve the best economic performance, while carbonyl sulfide (COS), R32 and R161 achieve the best thermodynamic performance. The highest net power, 12.5 MW, is achieved with COS, whereas the lowest LCOE (80 €/MWh) and SIC (6000 €/kW) are obtained with R32, all for an LNG regasification capacity of 700,000 Sm3/h.

Bridging the gap between theoretical heat exchanger analysis and physical intuition remains a persistent challenge in engineering education, particularly when students are confronted with real-system effects such as pressure losses, measurement uncertainty, and deviations from simplified models. This work addresses this challenge through the coupled development of a pedagogical framework and an experimental platform. A modular heat exchanger test bench was conceived, designed, and constructed by graduate students within a structured project-based learning environment, in which competitive and cooperative phases were combined to emulate real engineering practice. This approach positions the test bench not only as a laboratory tool, but as the outcome of an active learning process that integrates system design, instrumentation, and modeling. The resulting platform enables the comparative study of multiple heat exchanger technologies—including three water-to-water heat exchangers (plate, shell-and-tube, and double-pipe) and one air-to-water fin-and-tube heat exchanger—under parallel, counterflow, and crossflow arrangements across a wide range of operating conditions. Comprehensive instrumentation (temperature, flow rate, and pressure measurements) supports rigorous energy balance analysis, effectiveness evaluation, and hydraulic performance assessment. Beyond undergraduate experimentation, the test bench provides a framework for advanced learning objectives, including uncertainty propagation, ε-NTU analysis, model development, and experimental validation. The confrontation between model predictions and experimental data, including observed discrepancies, is shown to play a central role in developing critical engineering judgment. The proposed approach demonstrates how the integration of project-based learning with a reconfigurable experimental platform can create a sustainable and scalable environment for heat transfer education.