Industrial thermal systems like process heating, steam generation, drying, cooling, and heat recovery account for approximately 20% of global CO2 emissions, yet the operational layer at which thermal energy is actually lost remains invisible in most production environments. This perspective argues that decision-system design, the deliberate architecture through which thermal performance is monitored, interpreted, and corrected, represents a missing third dimension of sustainable thermal engineering alongside thermal product design and thermal process design. Closing this thermal intelligence gap requires manufacturing systems in which thermal flows are continuously visible and correctable. Stage-level monitoring reveals transition-state losses invisible to facility-level accounting; correcting these through lightweight data-driven approaches, without capital replacement, can yield site-level thermal energy reductions of 15%–25%. For small and medium-sized enterprises, accessible thermal intelligence tools offer a practical route to meaningful decarbonisation without enterprise-scale capital investment.
Sanjid S. Chirammel, Aritra Mukherjee, Luca Brandt, Jannike Solsvik
This study presents a novel sharp interface approach based on the level set method that achieves improved mass conservation and reduced computational time without introducing additional complexities in numerical implementation. The proposed approach is built upon recent formulations: the conservative phase field (CPF) method, the conservative diffuse interface (CDI) method, and the sharp interface level set method on co-located grid (SI − LSM col). While the CPF and CDI methods advect the interface while preserving the boundedness criterion associated with the hyperbolic tangent-based interface advection function, the SI − LSM col ensures pressure-interfacial force balance on a co-located grid. Implementation in a three-dimensional coordinate system further demonstrates the robustness of enforcing jump conditions as interfacial boundary conditions for high density ratio simulations on co-located grids. Validation against several benchmark test cases—including the Young–Laplace law, rising bubble, falling droplet, and droplet coalescence—along with comparisons to the previous SI − LSM col method, shows improved mass conservation and reduced computational time, achieved without any loss in computational accuracy.
This study investigates a desorption-driven sorption cooling approach as an alternative to conventional thermally regenerated adsorption cooling systems. The approach utilizes the endothermic heat of desorption directly for cooling by reducing the adsorbate partial pressure, potentially enabling operation near ambient temperature without an external regeneration heat source. As a representative implementation, a variable-volume adsorption cooling (VVAC) system is investigated, in which the required reduction in water vapor pressure is achieved through controlled expansion of the adsorber volume. The influence of the initial water vapor pressure and the ratio of final to initial adsorber volumes on system performance was analyzed using a simplified theoretical model for the zeolite-water working pair. Lower initial pressures and larger volume ratios (V 2 /V 1) were found to promote greater water desorption from both NaX and NaY zeolites. The initial amount of water desorbed from NaX reached approximately 0.25 g/g zeolite at an initial pressure of 0.5 kPa and V 2 /V 1 = 50, while NaY exhibited about 10%–35% higher desorption under comparable conditions. The calculations further revealed two characteristic operating regimes, in which the adsorbate partial pressure and water loading in the zeolite exhibited either decaying or approximately persistent oscillatory behavior arising from the coupling between vapor desorption and pressure variation. Under the idealized assumptions adopted in the present study, the minimum reversible work required to initiate the pressure reduction was found to be considerably smaller than the thermal energy released through the adsorption-desorption equilibrium, indicating favorable thermodynamic potential for the proposed concept. The results indicate the thermodynamic potential of pressure-induced desorption as a cooling mechanism in a water–zeolite adsorption system and provide a basis for further investigation of low-work implementations, including variable-volume operation.
Dongyang An, Shuangshuang Cheng, Zhao Liu, Shi Cheng, Jiaye Chen, Zengwu Tang, Jingmin Dai, Peng Xiao
Accurate infrared emissivity characterization of high-temperature materials under vacuum conditions remains challenging. To address this issue, a vacuum-compatible infrared measurement system based on direct electric heating was developed. The system supports rapid and stable heating from 500 °C to over 3,000 °C with a temperature control accuracy of ±5 °C. It integrates a Fourier Transform Infrared spectrometer and adopts a conversion blackbody method for real-time emissivity measurement under vacuum conditions. The design eliminates external heating sources, enhancing responsiveness and adaptability in extreme environments. The system achieves a radiative measurement uncertainty below 2%, providing a reliable approach for emissivity characterization and thermophysical property evaluation of refractory materials in aerospace, laser processing, and optical applications.
Farhan Ali, Imtiaz Hussain, S. S. Zafar, Muhammad Faizan Ahmed
This study examines heat and species-transport phenomena in a Darcy–Forchheimer porous framework that carries a stretching sheet onto which Walter’s-B nanofluid containing gyrotactic microbes is injected. The physical model combines radiative heat transfer, Brownian agitation, thermophoretic drift, chemical kinetics, and the Cattaneo–Christov double-diffusive formalism with thermal, solutal, and bioconvective stratification boundary conditions. After some similarity transformations, the primitive partial differential equations are transformed into a very nonlinear coupled ODE system, which we semi analytically using the homotopy analysis method, and convergence is verified by study of ℏ-curves and residual error tables. The results indicate that the velocity field decreases significantly with an increase of the Forchheimer inertia and the porosity parameter, which both increase the hydraulic resistance of the porous medium. On other hand, Walter’s-B viscoelastic parameter enhances the momentum diffusivity and thus speeds up flow. When thermal radiation, Brownian motion and thermophoresis increase, the temperature profiles widen noticeably; however, thermal stratification has the opposite effect, decreasing the thermal penetration depth by decreasing the wall-to-fluid temperature difference. The concentration distributions of the nanoparticles decrease significantly as the solutal stratification increases or the reaction rates increase—solutal stratification will reduce the driving concentration gradient, and the chemical reaction will consume the diffusing species. The microbial stratification factor and Péclet number are important for controlling bioconvection intensity, and their increase decreases the local population density for motile microorganisms. With the inclusion of wall shear, increments in the Darcy, Forchheimer, and viscoelastic parameters are shown to lead to an increase in the skin-friction coefficient, denoting improved interfacial momentum transfer. The effectiveness of heat transfer (Nusselt number) increases with the intensity of the radiative effects and decreases with the effects of thermophoresis, in which nanoparticles deviate away from the hot surface. Meanwhile, the density number for motile microorganisms increases with the bioconvection Lewis number, highlighting the important role of the diffusivity of microorganisms in the maintenance of the bioconvection flux. In conclusion, the present findings provide a clear understanding of the multi-physical control of heat, mass, and microbe transport in non-Newtonian nanofluidic systems.
