Thermal Science and Engineering Progress最新文献

With the global emphasis on sustainable development, green manufacturing has become a key strategy to enhance economic efficiency and environmental friendliness. In the manufacturing process, the effective use and management of heat energy directly affect the consumption of resources and the protection of the environment. Blockchain technology, with its transparency and immutability, has gradually been introduced into the production process, helping to achieve traceability and optimization of thermal energy utilization. This study aims to explore how to combine computer technology with blockchain to establish a heat energy monitoring and management system based on computer technology, and collect real-time heat energy data through sensors. It then uses blockchain technology to create a transparent production traceability platform, store and manage thermal data, and ensure the security and reliability of the data. The research shows that the system combining computer technology and blockchain significantly improves the utilization efficiency of heat energy, greatly reduces the heat loss in the production process, and significantly improves the reuse rate of resources. The traceability function of the system effectively improves the transparency of the production process and enables enterprises to adjust their production strategies in time. Therefore, the combination of computer-based thermal efficiency utilization with blockchain production traceability offers a new solution for green manufacturing.

Based on topology optimization method, a dual-objective function topology optimization model containing minimum average temperature and minimum flow power dissipation was established in this study. Coupled with the uneven heat generation model of proton exchange membrane fuel cells, the optimal layout scheme under the target operating conditions was adaptively obtained. The effects of volume fraction, objective function weight, and parabolic inlet velocity on the flow channel structure and cooling performance of topological cooling plates were studied. The results indicate that with the increase of volume fraction, the area of fluid region increases, the average temperature and the pressure drop of cooling plate gradually decrease. At the volume fraction of 0.5, the cooling plate has the best cooling performance. The temperature difference and maximum temperature reach the minimum values of 5.45 K and 347.58 K, respectively. When the volume fraction increases from 0.4 to 0.6, the pressure difference decreases by 67.64 %. With the increase of temperature weight coefficient, the area of high-temperature area gradually decreases, and the temperature uniformity is significantly improved. When the inlet velocity of coolant is 0.025 m/s and the temperature weight coefficient is 0.9, the average and maximum temperatures of cooling plate reach the lowest values, which are 343.53 K and 344.51 K, respectively. The maximum temperature of cooling plate under parabolic inlet velocity is of 347.87 K, which is 0.29 K higher than that under uniform inlet velocity. Non-uniform coolant inlet velocity will lead to a decrease in heat transfer capacity of cooling plate and an increase in coolant power consumption.

In this article, we aim to study the effects of applied heat flux, magnetoconvection and nanoparticle concentration on the magnetite-water (${\mathrm{Fe}}_3{O}_4-H_{2}O$) ferrofluid flow and melting heat transfer through a partially-porous annulus. This annular region is bounded by a heated inner cylinder and melting outer cylindrical ice wall. The flow is influenced by an alternating magnetic field generated by a current carrying wire within the inner cylinder, and the Brinkman–Forchheimer model is used to describe the ferrofluid flow through the porous region. Using the finite element method (FEM) on the coupled non-linear system of governing equations, we generate graphical results via MATLAB. The numerical algorithm developed for solving this problem is validated against published work in the literature with a maximum relative error of 5%. Results show that reductions in magnetoconvection, initial thickness of ice, nanoparticle volume fraction, or an increase in heat generated by inner cylinder increases the rate of melting of ice, with computed percentage increases of 12.7%, 72.1%, 4.7%, and 22.1% respectively. The axial velocity of the ferrofluid is decreased with an increase in magnetoconvection or increased rate of melting; however, this increases the amplitude of the radial velocity component. The cooling performance of the ferrofluid increases with increased magnetoconvection (5.2%), nanoparticle volume fraction (5.9%), and initial thickness of ice (52.1%). Based on these results the ferrofluid is more efficient at cooling the heated cylindrical wall than melting the ice.

Studying the dynamic processes of quartic autocatalysis chemical reactions in Williamson nanofluid flow over a parabolic surface is significant for optimizing and enhancing the efficiency of industrial and engineering systems involving complex fluid dynamics and chemical reactions. The investigation of the type of flow channel is very important. In the present problem, the motion is investigated on an upper horizontal surface of a paraboloid of revolution. The analysis is performed about the Williamson nanofluid flow with Cattaneo–Christov (C–C) heat flux, quartic autocatalysis chemical reaction and gyrotactic microorganisms motion past an upper horizontal surface of a paraboloid of revolution (uhspr). Similarity transformations are applied to get the non-dimensional equations in differential form. Homotopy Analysis Method (HAM) is operated for computing the solution. The solution is processed to obtain the results which have been shown through the graphs which note the effects of existing parameters on profiles. The computed results have a nice agreement with the published results. The investigations are about the upper horizontal surface of a paraboloid of revolution which has leading role in science, aerodynamics like surface of a rocket, bonnet of a car and pointed surface of a vehicle and airplane.

Atom search optimization (ASO) algorithm derived from physics molecular dynamics. Lennard-Jones(L-J) and bond length potential of molecules are used to derive the model for optimization. In this paper, ASO is used for developing a nonlinear Fractional Order Proportional Integral Derivative controller (NL-FOPID) for Continuously Stirred Tank Reactor (CSTR). The convergence characteristics of ASO was improved by proposing a novel hybridization approach. The proposed hybridization approach called Hybrid ASO(HASO) guides the Atom search algorithm to optimally replace the atoms that goes out of the boundary of the search space. The designed algorithm is implemented to optimize various unimodal and multi model standard benchmark functions. From results obtained from this extensive simulation, it is indicated that proposed approach increased the convergence rate and also improved the optimization effort of conventional ASO. The proposed algorithm also tested with controller design for nonlinear CSTR. The NLPID and NL FOPID designed by HASO was better than conventional controllers found in the literature.

The phenomenon of heat dissipation and exergy transfer during the respiratory process in the human body holds significant importance concerning thermal comfort and wellness. In this study, the effect of the environmental condition of the Kastamonu and Karabük Provinces in the Türkiye’s West Blacksea region on human body thermoregulation behavior has been investigated for the last eight years (2015–2022). It has been found that the cumulative heat loss and entropy generation associated with human respiration are markedly influenced by seasonal and environmental fluctuations. Besides, it has been detailly examined that the effects of average air temperature, average relative humidity, and average atmospheric pressure used as meteorological data on energy loss, entropy generation, and exergy flow have been investigated. The results reveal that most heat loss originates from metabolism energy at the rate of 5.935 W/m². In addition, it was observed that heat exchange realized by passive systems such as convection and evaporation exhibited the maximum energy loss. Moreover, the results revealed that an increment in environmental temperature and relative humidity causes a decrement in convective heat loss. An evaluation of lowest heat loss and the highest exergy values was obtained specifically for İnebolu distriction (PZ-3). Accordingly, the minimum finding in heat loss, quantified as 1.9099 W/m², was observed in the month of August, while the zenith in exergy, reaching 0.2846 W/m², was likewise noted during the same temporal interval. Besides, the level of thermal comfort at each location is computed. According to the predicted mean vote (PMV) and Predicted Percentage Dissatisfied (PPD) indexes, it was concluded that the dissatisfaction of the atmospheric conditions in the provinces in four seasons is high on the human body.

Historic buildings have significant cultural, scientific, and aesthetic value, and show the accomplishments of past eras. Unfortunately, many historic buildings are being destroyed by fires across the world. Currently, wooden historic building fires occur frequently in China without effective fire control measures. To clarify the current characteristics of these buildings in China, the present work comprehensively investigates fire disaster data from the past ten years and then discusses the main causes of fires and their fire characteristics. In addition, the research progress on the corresponding fire protection, damage evaluation, restoration, and prospect are also discussed. The analysis has concluded that the primary causes of fires are related to electrical factors, careless use of fire, and arson. Fire protection measures and management suggestions are then provided for Chinese wooden historic buildings.

This study investigates the impact of introducing horizontal barriers within the internal cavity of flat plate solar collectors on their thermal efficiency. The primary objective is to enhance thermal performance by reducing convective heat loss. An experimental test bench was constructed to evaluate five solar collectors under controlled conditions. One collector was unmodified as a reference, while the other four had 1 to 4 horizontal barriers inserted between the absorber plate and glass cover. Each collector’s efficiency was assessed by measuring inlet and outlet water temperatures, incident solar radiation, ambient temperature, and water flow rate. Efficiency versus heat loss parameter curves were generated, and correction factors were applied to account for material and sensor differences. The collector with four barriers demonstrated the highest overall thermal efficiency, achieving an efficiency improvement of up to 12 % compared to the reference collector. Specifically, the efficiency of the reference collector was around 70 %, while the collector with four barriers reached an efficiency of approximately 82 %. Introducing two barriers resulted in a 9 % increase in efficiency, bringing it to about 79 %. Conversely, the collector with three barriers showed a slight decrease in efficiency to 68 %. The barriers effectively reduced internal convective heat loss, enhancing the collector’s ability to harness incident solar radiation. Inserting horizontal barriers within the internal cavity of flat plate solar collectors significantly improves thermal efficiency by reducing convective heat loss. The optimal configuration, based on this study, involves using four barriers. This method presents a straightforward yet effective approach to enhancing solar collector performance. Future research should focus on refining barrier design and placement for different collector sizes and geometries, potentially supporting broader adoption of solar thermal energy systems and contributing to sustainable energy solutions.

Solar greenhouses play a crucial role in winter crop cultivation in the cold regions of China. However, adverse weather conditions such as low temperatures can negatively affect their production. Therefore, improving the greenhouse thermal environment and energy utilisation is crucial for optimising greenhouse productivity. One effective method of storing energy is phase change technology. In this study, melt blending was used to prepare composite phase change materials (CPCMs), with methyl palmitate and hexadecanol as raw materials. In addition, ceramsite was encapsulated with a styrene-acrylic emulsion to form a shape composite phase change material (SCPCM). The results showed that the latent heat of phase change of the CPCMs was 221 J/g, with an initial phase change temperature of 23.48 ℃. The encapsulation of the SCPCM with a styrene-acrylic emulsion significantly reduced leakage. Phase-change ceramsite concrete slabs were developed by integrating the SCPCM into concrete. These slabs were used to construct phase-change and non-phase-change greenhouses. A temperature-testing system was installed in the greenhouses to examine the temperature variations and distributions under typical sunny and cloudy conditions. Results revealed that compared with the control greenhouse, the phase-change greenhouse exhibited a decrease of 3.0 ℃ in the maximum indoor temperature during sunny days and an increase of 3.2 ℃ in the minimum indoor temperature at night. This study highlights the effective temperature control capabilities of phase-change ceramsite concrete slabs for improving energy utilisation and provides valuable theoretical and technical insights for the future utilisation and widespread adoption of phase-change greenhouses.

This work aimed to determine drying behavior and energy consumption of limequat peels dried using ultrasound-assisted vacuum drying (UAVD), vacuum-assisted drying (VAD), oven drying (OD) and vacuum drying (VD), and investigate thermogravimetric decomposition, morphological, elemental and spectral analyses of dried peels with energy efficiency analysis including specific moisture extraction rate (SMER), moisture extraction rate (MER) and specific energy consumption (SEC). The UAVD considerably shortened drying time by 49 %, 34 % and 15 % as compared to the OD, VAD and VD. The highest drying rate was achieved at the UAVD. The effective moisture diffusivity (D_eff) values in descending order were UAVD>VD>VAD>OD. Proximate analysis showed that limequat peels dried using the UAVD had the highest fixed carbon (25.35 %) and ash (3.03 %) contents, but the lowest volatile matter (61.68 %). Dried limequat peels exhibited similar thermal decomposition behavior. The UAVD caused porous and rough surface formation, and microchanneling effect. Carbon (>62.56 %) and oxygen (>15.98 %) were the major elements in dried limequat peels. The lowest O/C (0.25) and H/C (0.85) ratios were obtained for the limequat peels dried using the UAVD. Fourier-transform infrared spectroscopy (FTIR) spectra showed primarily O–H, C–H, CO, CC and C–O–C stretching vibrations. The highest SMER (0.0053 kg/kWh) and MER (0.0012 kg/h) values, and the lowest SEC (188.27 kWh/kg) value were determined for the UAVD. In conclusion, the UAVD was found to be the most appropriate drying method for the drying of limequat peels.