Solar ejector refrigeration can reduce building cooling electricity demand by utilizing low- and medium-temperature solar heat, but its performance is sensitive to solar radiation and ambient temperature. To improve off-design performance, this study developed a TRNSYS-EES dynamic model of a solar ejector-compression hybrid refrigeration system for a residential building in Zhengzhou and proposed a weather-responsive, rule-based control strategy. The strategy integrates time- and temperature-difference-based control of the solar collection and storage subsystem with variable generation-temperature regulation according to ambient temperature and solar radiation. Model predictions agreed with experimental ejector cooling capacities within 2.9-5.2%. Under typical-day conditions, the proposed strategy increased the ejector cooling capacity from approximately 3.0 to 3.5 kW (16.7%), while maintaining a COP of 0.23-0.26. In hybrid mode, cooling output became more stable and reached 11.53 kW, generally meeting the building cooling demand. The results demonstrate that weather-responsive generation-temperature regulation improves cooling stability and adaptability under short-term weather fluctuations.
Timely warning is important for reducing the fire and propagation risks associated with lithium-ion battery thermal runaway. However, a warning method that performs well with ideal temperature data may become too slow when real sensor and communication limitations are considered. This study analyzed 58 Main mechanically induced thermal-runaway tests, including 50 reference-positive events and a 24-event high-severity subgroup, together with a 16-event strong-event cohort originating from Sandia National Laboratories (SNL). Recorded temperature histories were modified to represent sensor response delay, measurement error, finite resolution, communication delay, packet loss, and short data interruptions. Warning performance was evaluated using a causal temperature-and-rise-rate alarm. Sensor response was the main sensing limitation: in the complete Main cohort, an additional response-time constant of 0.7 s was the largest tested value retaining at least 95% timely-warning reliability. Dispersed packet loss had little effect, but a 1 s continuous data gap near alarm confirmation reduced reliability to 70.83% and 75.0% in the two strong-event cohorts. Combined analysis identified a candidate region of response-time constant ≤0.9 s and communication/processing delay ≤0.5 s, with 95.69% nominal conservative reliability. These results show that fast sensing and uninterrupted data delivery should be designed together for reliable thermal-runaway early warning.
Based on a 120-t single plug ladle in a steel plant, a full-scale three-dimensional unsteady steel-slag-gas three phase coupled flow model was established to calculate the multiphase flow field and temperature field inside the ladle during the soft blowing (inclusion removal stage) under different bottom-blowing pressures and initial temperatures. On this basis, the discrete phase model combined with a user defined function was employed to simulate the motion, collision, flotation and removal of inclusions in molten steel. Considering the smoothing effect of the k-ε model and the fact that the driving force acting on inclusions mainly originates from the molten steel, large-eddy simulation was adopted to describe the turbulent flow more accurately and obtain more realistic inclusion motion. The results show that LES captures more detailed flow structures than RANS, leading to a more accurate prediction of inclusion removal efficiency. The inclusion removal rate increases with bottom-blowing argon pressure; at 8 min, the removal rates under 0.2, 0.35 and 0.5 MPa are 70.1%, 74.2% and 76.4%, respectively. Taking 0.35 MPa as an example, the removal rate exceeds 98% within 24 min, and then increases by only to 0.718% between 24 and 30 min. Meanwhile, the initial temperature has a limited effect on inclusion removal efficiency.
The growing demand for environmentally sustainable construction materials has led to increased research into alternative solutions for noise control. This paper presents a survey of sustainable acoustic materials, with a particular focus on recycled textile hemp-based insulation systems. While natural and recycled materials offer significant ecological advantages, their acoustic performance often lags behind conventional synthetic solutions. The study highlights recent advancements in plasma surface treatment of polymeric materials as an innovative and environmentally friendly method for enhancing the acoustic properties of recycled textiles. By modifying fibre surface morphology and improving airflow resistivity, plasma treatment significantly enhances sound absorption and insulation capabilities. The integration of recycled hemp based materials with plasma technology represents a promising pathway toward high-performance, low-impact acoustic solutions aligned with circular economy principles.
Water temperature prediction for overhead aqueducts is the basis for analyzing ice conditions and developing winter thermal insulation schemes for aqueducts. In this research, we propose an enhanced water temperature model that accounts for the coupled heat transfer processes in overhead aqueducts, incorporating water, aqueduct, and insulation material characteristics. The proposed model systematically incorporates key environmental factors, including solar radiation, evaporative cooling, convective heat transfer, and wind speed effects, while establishing a coupled heat exchange framework that quantifies the thermal interactions among flowing water, aqueduct structures, and insulation materials. With regard to the characteristics of heat dissipation in the water of the overhead aqueducts, this study focuses on the effect of wind speed on the convective heat transfer process of the concrete primary liner and insulation materials. Meanwhile, the relationship between convective heat transfer coefficients of three materials, namely, rubber-plastic foam, fiberglass, and polyurethane, and wind speed was obtained through indoor experimental measurements. The actual observation data from Caohe aqueduct are used to verify the proposed water temperature model without covering insulation materials. Based on the historical meteorological data of Caohe aqueduct, the change of water temperature along the Caohe aqueduct of the South-to-North Water Diversion Central Route is predicted with different thicknesses of insulation materials. The results show that the water temperature at the exit section of the aqueduct is expected to be higher than zero degrees without ice conditions if the aqueduct is covered with a 5 cm thick polyurethane or 7 cm thick rubber-plastic layer.
