Thermal Science and Engineering Progress最新文献_第3页

Comparative data analysis of radiative MHD Bingham and Newtonian fluid past a Non-Linear stretching sheet with thermoelectric and Joule effects 辐射 MHD 宾汉姆流体和牛顿流体流过非线性拉伸片时的热电效应和焦耳效应数据对比分析

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress

Pub Date : 2024-11-17 DOI: 10.1016/j.tsep.2024.103056

Md. Yousuf Ali

This work presents a comparison of radiative magnetohydrodynamics (MHD) Bingham and Newtonian fluids across a nonlinear stretching sheet (SS), considering thermoelectric effects, chemical processes, and Joule heating. The governing equations are converted into Ordinary Differential Equation (ODE) form using suitable non-dimensional variables and parameters as well as employed a numerical strategy that combines the Nachtsheim-Swigert (N-S) shot method with the 6th order Runge-Kutta (R-K) algorithm. Comparing the behaviors of Bingham and Newtonian fluids is the main objective, which reveals intricate linkages between different physical phenomena, chemical processes, and radiative MHD on nonlinear stretching sheets. The dynamics of concentration, primary and secondary velocities, skin friction, heat and mass transfer rates, temperature, and other dimensionless parameters are graphically presented in the research. Important results indicate that compared to Newtonian fluid flow, Bingham fluid flow decreases primary velocity by 7.01% greater. Furthermore, on a nonlinear stretching sheet, temperature increases by 38.09% higher than on a linear one. In Newtonian fluid, thermal radiation acts as an increasing factor but in Bingham fluid, it acts as a decreasing factor. At a 95% confidence level, the regression analysis shows a substantial interaction between factors influencing the Nusselt number, with correlation values (R²) of 98.11% for Bingham fluids and 98.79% for Newtonian fluids. The Nusselt number and Joule heating for Newtonian fluid have a correlation study of 90.90%, whereas for Bingham fluid it is 83.69%. The improved thermal performance linked with Bingham fluid flow is highlighted by these studies, which have potential in tissue engineering, medication delivery systems, and renewable energy.

本研究比较了非线性拉伸片（SS）上的辐射磁流体（MHD）宾汉流体和牛顿流体，并考虑了热电效应、化学过程和焦耳加热。利用合适的非维度变量和参数将控制方程转换为常微分方程（ODE）形式，并采用了结合纳赫茨海姆-斯维格特（N-S）射出法和六阶 Runge-Kutta 算法的数值策略。主要目的是比较宾汉流体和牛顿流体的行为，揭示非线性拉伸片上不同物理现象、化学过程和辐射 MHD 之间错综复杂的联系。研究以图表形式展示了浓度、一次和二次速度、表皮摩擦、传热和传质速率、温度和其他无量纲参数的动态变化。重要结果表明，与牛顿流体流动相比，宾厄姆流体流动的一次速度降低了 7.01%。此外，在非线性拉伸片上，温度的升高比线性拉伸片高 38.09%。在牛顿流体中，热辐射是一个增加因素，但在宾汉流体中，热辐射是一个减少因素。在 95% 的置信水平下，回归分析表明影响努塞尔特数的因素之间存在实质性的相互作用，宾汉流体的相关值 (R2) 为 98.11%，牛顿流体的相关值 (R2) 为 98.79%。牛顿流体的努塞尔特数与焦耳热的相关性为 90.90%，而宾汉流体的相关性为 83.69%。这些研究强调了与宾汉流体流动相关的热性能改善，这在组织工程、药物输送系统和可再生能源方面具有潜力。

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引用次数: 0

On the effect of a tangential intake on the performance of natural dry draft cooling towers in crosswind conditions 切向进气口对横风条件下自然干式通风冷却塔性能的影响

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress

Pub Date : 2024-11-16 DOI: 10.1016/j.tsep.2024.103036

Behzad Zakeri , Morteza Khashehchi , Pooyan Rahmanivahid , Milad Heidari

Crosswind has a negative effect on the performance of natural draft dry cooling towers, NDDCTs, serving thermal power plants. This, in turn, lowers the efficiency of the thermal power plant as less heat can be rejected to the ambient air through the tower. This occurs due to interaction of cross wind and cooling tower structure. This phenomenon leads to generation of primary and secondary vortices inside the tower which located in leeward side (downwind side) and windward side (upwind side) of the tower, respectively. In an innovative interpretation of the challenge, this paper aims at directing the crosswind flow through the tower shell above the heat exchangers to assist the buoyancy-induced plume. In particular, the intake of the crosswind through the tower is utilized as a tangentially-induced swirl source to help the upward draft, and its penetration in the ambient air, enhancing the tower performance which otherwise would have been significantly deteriorated. Two independent approaches are presented to assess the proposed design quantitatively. CFD simulation of a small scale tower model has revealed significant performance improvement (in terms of natural draft blockage and outlet flow velocity) when the crosswind is allowed to penetrate the tower shell, through an opening on the tower side-wall, above the heat exchangers. Results of the simulations have been validated against the experimental data collected using the tests ran on an identical model, with and without the side opening, in a wind tunnel.

横风会对为火力发电厂服务的自然吸风干式冷却塔（NDDCT）的性能产生负面影响。这反过来又降低了火力发电厂的效率，因为通过冷却塔排到环境空气中的热量减少了。这是由于横风和冷却塔结构之间的相互作用造成的。这种现象导致塔内产生一级和二级涡流，分别位于塔的背风侧（下风侧）和迎风侧（上风侧）。本文对这一挑战进行了创新性的解释，旨在引导横风流通过热交换器上方的塔壳，以辅助浮力引起的羽流。特别是，利用横风通过塔的吸入口作为切向诱导漩涡源，帮助向上的气流及其在环境空气中的渗透，从而提高塔的性能，否则，塔的性能将大大降低。本文提出了两种独立的方法来定量评估拟议的设计。对小规模塔模型进行的 CFD 模拟显示，当横向风通过塔侧壁热交换器上方的开口进入塔壳时，塔的性能（在自然气流阻塞和出口流速方面）将得到显著改善。模拟结果与在风洞中对相同模型（有无侧开口）进行测试所收集的实验数据进行了验证。

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引用次数: 0

6E evaluation of an innovative humidification dehumidification solar distiller unit: An experimental investigation 6E 评估创新的加湿除湿太阳能蒸馏器装置：实验研究

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress

Pub Date : 2024-11-14 DOI: 10.1016/j.tsep.2024.103052

A.S. Abdullah , Mamoun M. Elsayad , Sulaiman Almoatham , Swellam W. Sharshir

This work aims to enhance the productivity, efficiency, energy utilization, feasibility, and environmental outcomes of solar desalination systems via representing an innovative humidification dehumidification solar distillation unit coupled with a built-in air solar heater and photovoltaic thermal unit. The air solar heater was further improved by the incorporation of copper chips as thermal energy-storing materials for extending the desalination process during the sun’s hours. Three distinct humidifier beds, including plastic waste (case A), wick materials (case B), and cellulose paper (case C) were tested and compared regarding system temperatures and hourly and daily drinkable water yield. Additionally, a 6E analysis was assessed and evaluated in terms of energy, exergy, economic, exergoeconomic, exergoenvironmental, and exergoenviroeconomic analysis for all the cases. According to the outcomes, the humidification dehumidification solar distiller with cellulose paper yielded the highest productivity and 6E outcomes where the daily drinkable water, thermal efficiency, and exergy efficiency were estimated as 7.78 L/m², 73.45 %, and 5.3 %, outperforming the CSD by nearly 142.59 %, 144.02 %, and 229.19 %, respectively. Moreover, the price of drinkable water and the payback time decreased to 0.0099 $/L and 0.12 years, which represents a reduction of 68.27 % and 69.23 %, respectively, at an exergoeconomic factor of 4.19 kWh/$. Furthermore, the amount of CO₂ reduced was increased to 3.92 tons, which is associated with earned credits of carbon of 56.78$. Finally, for this case, the HDH humidifier efficiency, dehumidifier effectiveness, and gain output ratio maximum and mean values were 96.66 and 84.5 %, 85.61 and 78.96 %, and 1.86 and 1.08, respectively.

这项研究旨在通过创新的加湿除湿太阳能蒸馏装置，结合内置的空气太阳能加热器和光伏热能装置，提高太阳能海水淡化系统的生产力、效率、能源利用率、可行性和环保效果。通过将铜片作为热能储存材料，进一步改进了空气太阳能加热器，以延长日照时间内的海水淡化过程。对三种不同的加湿器床进行了测试，包括塑料废料（情况 A）、灯芯材料（情况 B）和纤维素纸（情况 C），并就系统温度以及每小时和每天的饮用水产量进行了比较。此外，还从能源、放能、经济、排气经济、排气环境和排气环境经济分析等方面对所有情况进行了 6E 分析评估。结果表明，使用纤维素纸的加湿除湿太阳能蒸馏器的生产率和 6E 结果最高，每天的可饮用水、热效率和放能效估计分别为 7.78 L/m2、73.45 % 和 5.3 %，分别比 CSD 高出近 142.59 %、144.02 % 和 229.19 %。此外，饮用水价格和投资回收期分别降至 0.0099 美元/升和 0.12 年，按 4.19 千瓦时/美元的外部经济系数计算，分别降低了 68.27 % 和 69.23 %。此外，减少的二氧化碳量增加到 3.92 吨，获得的碳信用额为 56.78 美元。最后，在这种情况下，HDH 加湿器的效率、除湿器的效果和增益输出比的最大值和平均值分别为 96.66%和 84.5%、85.61%和 78.96%，以及 1.86%和 1.08%。

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引用次数: 0

Performances of a gas turbine power plant with a direct evaporative saturator 带直接蒸发饱和器的燃气轮机发电厂的性能

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress

Pub Date : 2024-11-14 DOI: 10.1016/j.tsep.2024.103047

Samira Pourhedayat, Eric Hu, Lei Chen

One way to improve the performance of gas turbine power plants is to saturate the compressed air (from the compressor) before it enters the combustion chamber, using a saturator. Indeed, utilization of an air saturator has the potential to augment the enthalpy within the combustion chamber, which may ultimately lead to an enhancement in the overall performance of the gas turbine. A direct evaporative cooler (DEC) is proposed as the saturator, i.e. DES for the GT plant in this study. The impact of the DES on the performance of the GT power plant has been studied in general through a sensitivity analysis and specifically through a case study, using an analytical model developed in this study and programmed in Engineering Equation Solver (EES) software. It has been demonstrated that increasing the inlet air and water temperatures in a DES system can lead to a notable enhancement in the performance of a gas turbine. The findings of the study indicated that the utilization of a DES could result in an increase of up to 7 % in power output and thermal efficiency of the GT in comparison to a gas turbine that does not possess a saturator. This improvement is achievable if waste heat is partially recovered through a heat recovery system (HRS) and employed for the purpose of preheating both the compressed air and water that are entering the DES. This improvement is approximately 6 % and 4 % respectively, if only the saturator inlet water or air temperatures were increased separately.

提高燃气轮机发电厂性能的一种方法是在压缩空气（来自压缩机）进入燃烧室之前使用饱和器使其饱和。事实上，使用空气饱和器有可能增加燃烧室内的热焓，从而最终提高燃气轮机的整体性能。本研究建议采用直接蒸发冷却器 (DEC) 作为饱和器，即 GT 设备的 DES。本研究使用工程方程求解器 (EES) 软件编程开发了一个分析模型，通过敏感性分析和案例研究，研究了 DES 对 GT 发电厂性能的总体影响。研究表明，提高 DES 系统的进气温度和水温可显著提高燃气轮机的性能。研究结果表明，与没有饱和器的燃气轮机相比，使用 DES 可使燃气轮机的功率输出和热效率提高 7%。如果通过热回收系统 (HRS) 回收部分废热，并将其用于预热进入 DES 的压缩空气和水，则可实现这一改进。如果只分别提高饱和器入口水或空气的温度，则可分别提高约 6% 和 4%。

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引用次数: 0

Analysis of OLED glass substrate heated by heating tube array based on multiple optimization algorithms 基于多重优化算法的加热管阵列加热 OLED 玻璃基板分析

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress

Pub Date : 2024-11-14 DOI: 10.1016/j.tsep.2024.103053

Yiyi Wang , Chang Xu , Huikun Cai

The temperature uniformity of OLED glass substrate during heat treatment is a key factor affecting the quality of its imaging display. This paper constructs the heating process model of OLED glass substrate based on heating tube array according to the actual scene, studies the thermal characteristics of OLED glass substrate, and then optimizes the temperature uniformity of glass substrate under isometric heating mode based on genetic algorithm, particle swarm optimization algorithm and simulated annealing algorithm. Compared with the initial solution of the algorithm, the optimization rates of the three algorithms respectively reach 75.5%, 86.4% and 98.3%, and the temperature differences are reduced to 3.82℃, 1.44℃ and 0.30℃. Finally, an experimental platform is built to verify the optimization results of different algorithms. The absolute errors are 0.58℃, 1.46℃, 1.30℃ respectively, all lower than 1.5℃, which is within the allowable range of process requirements. It is proved that the proposed optimization algorithm control mode can reduce the heating temperature difference of glass substrate to the ideal level based on the heating device with low cost and simple structure. This scheme provides some reference for the formulation of temperature distribution solution in heat pipe heating technology.

OLED 玻璃基板在热处理过程中的温度均匀性是影响其成像显示质量的关键因素。本文根据实际场景，构建了基于加热管阵列的 OLED 玻璃基板加热工艺模型，研究了 OLED 玻璃基板的热特性，并基于遗传算法、粒子群优化算法和模拟退火算法对等距加热模式下玻璃基板的温度均匀性进行了优化。与算法初始解相比，三种算法的优化率分别达到 75.5%、86.4% 和 98.3%，温差分别降低到 3.82℃、1.44℃ 和 0.30℃。最后，建立了一个实验平台来验证不同算法的优化结果。绝对误差分别为 0.58℃、1.46℃、1.30℃，均小于 1.5℃，在工艺要求的允许范围内。实践证明，基于成本低廉、结构简单的加热装置，所提出的优化算法控制模式可将玻璃基板的加热温差降至理想水平。该方案为热管加热技术中温度分布方案的制定提供了一定的参考。

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引用次数: 0

Velocity-driven optimization of film cooling in methane/oxygen rocket engines using coupled wall function 利用耦合壁面函数对甲烷/氧气火箭发动机中的薄膜冷却进行速度驱动优化

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress

Pub Date : 2024-11-13 DOI: 10.1016/j.tsep.2024.103051

Jianing Liu , Silong Zhang , Jianfei Wei , Oskar J. Haidn

This study investigates the application of coupled wall functions to the research of film cooling in methane/oxygen rocket engine combustion chambers. By manipulating film mass flow rate and inlet size, the influence of different film-mainstream velocity ratios on flow dynamics, combustion, wall heat transfer, and cooling efficiency within the combustion chamber is explored. Results indicate that as the ratio of film velocity to mainstream velocity (R_V) increases, the combustion chamber pressure initially decreases before increasing, with a corresponding trend observed in vortex intensity at the inlet section. Comparative analysis reveals that, while maintaining a constant mass flow rate, reducing the film inlet height results in lower pressures and weaker swirl strength. Furthermore, wall heat transfer decreases gradually with increasing R_V, with lower heat transfer observed in cases involving additional low-temperature methane injection. Notably, the introduction of coupled wall functions minimally impacts mainstream flow and combustion. Analysis of Net Heat Flux Reduction (NHFR) indicates a rapid decrease in cooling efficiency in the front half of the combustion chamber, emphasizing the suitability of employing a film cooling inlet every one-fifth section in a methane/oxygen engine. Moreover, increasing the mass flow rate enhances cooling efficiency as R_V increases, while altering the inlet size yields nearly constant cooling efficiency. Therefore, maximizing film mass flow rate is deemed preferable for film cooling arrangements in a specific rocket engine; however, comparative studies reveal a gradual reduction in engine specific impulse with increasing mass flow rate, underscoring the necessity for engine-specific determinations.

本研究探讨了耦合壁面函数在甲烷/氧气火箭发动机燃烧室薄膜冷却研究中的应用。通过操纵薄膜质量流量和入口尺寸，探讨了不同薄膜主流速度比对燃烧室内流动动力学、燃烧、壁面传热和冷却效率的影响。结果表明，随着薄膜速度与主流速度之比（RV）的增加，燃烧室压力在增加之前会先降后升，入口部分的涡流强度也会出现相应的趋势。对比分析表明，在保持质量流量不变的情况下，降低薄膜入口高度会导致压力降低和漩涡强度减弱。此外，壁面传热随着 RV 的增加而逐渐减小，在额外注入低温甲烷的情况下，壁面传热更低。值得注意的是，耦合壁面功能的引入对主流流和燃烧的影响很小。净热流减少量（NHFR）分析表明，燃烧室前半部分的冷却效率急剧下降，这说明在甲烷/氧气发动机中每隔五分之一的部分采用薄膜冷却入口是合适的。此外，当 RV 增加时，增加质量流量可提高冷却效率，而改变入口尺寸则可获得几乎不变的冷却效率。因此，在特定的火箭发动机中，最大限度地提高薄膜质量流量被认为是薄膜冷却安排的首选；然而，比较研究显示，随着质量流量的增加，发动机的比冲逐渐减小，这突出表明有必要根据发动机的具体情况进行确定。

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引用次数: 0

Seasonal performance comparison of R-410A and R-454B in a variable-speed air-cooled scroll chiller 变速风冷涡旋式制冷机中 R-410A 和 R-454B 的季节性性能比较

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress

Pub Date : 2024-11-12 DOI: 10.1016/j.tsep.2024.103050

Avinash Kumar , Nitin Karwa , Ankit Sethi , Nilesh Purohit

In recent years, there has been increasing concern about the impact of air conditioning and refrigeration on global warming. This is particularly related to the emissions of refrigerants with high global warming potentials (GWP), such as R-410A, which is used in air conditioning and chiller systems. There has been a concerted effort within the HVAC industry to find lower GWP refrigerants to replace R-410A in HVAC systems. In this paper, a 10.5 kW (3 TR) air-cooled variable-speed scroll chiller has been utilized to conduct an experimental comparison of R-410A (GWP of 2088) and its low GWP A2L alternative R-454B (GWP of 466) according to AHRI 551/591 testing condition at rating and part load condition with optimized charge. The compressor speed and suction superheat were matched for both refrigerants at all the test conditions. R-454B shows 98 % capacity and 102 % efficiency compared to R-410A at rating conditions of 35 °C outdoors and water return temperature of 12 °C. The IPLV of the R-454B chiller was just 1 % higher than R-410A. The discharge temperature of R-454B and compressor isentropic efficiency is 8 % higher and almost like R-410A, respectively. The optimized charge of R-454B was 5 % lower refrigerant charge compared to R-410A. The LCCP analysis for major Indian cities over a 15-year operational span demonstrates a notable reduction, ranging from 6.6 % to 7.3 %, in overall R-454B emissions compared to R-410A. The study demonstrates that R-454B is a drop-in replacement to R-410A designs and reduces the direct GHG emission from the chiller by 76 %.

近年来，人们越来越关注空调和制冷对全球变暖的影响。这尤其与全球升温潜能值（GWP）较高的制冷剂排放有关，例如空调和冷风机系统中使用的 R-410A。暖通空调行业一直在共同努力寻找全球升温潜能值较低的制冷剂来替代暖通空调系统中的 R-410A。本文利用一台 10.5 千瓦（3 TR）风冷变速涡旋式冷水机组，根据 AHRI 551/591 测试条件，在额定负荷和部分负荷条件下进行了 R-410A（全球升温潜能值为 2088）和其低全球升温潜能值 A2L 替代品 R-454B（全球升温潜能值为 466）的实验比较，并进行了优化充注。在所有测试条件下，两种制冷剂的压缩机转速和吸气过热度都相匹配。在室外温度为 35 °C 和回水温度为 12 °C 的额定条件下，与 R-410A 相比，R-454B 的容量为 98%，效率为 102%。R-454B 冷风机的 IPLV 仅比 R-410A 高 1%。R-454B 的排气温度和压缩机等熵效率分别比 R-410A 高 8 % 和几乎相同。R-454B 的优化充注量比 R-410A 低 5%。对印度主要城市 15 年运行期的 LCCP 分析表明，与 R-410A 相比，R-454B 的总体排放量显著减少了 6.6% 到 7.3%。研究表明，R-454B 可以直接替代 R-410A 设计，并将冷风机的直接温室气体排放量减少 76%。

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引用次数: 0

Enhancing Li-ion battery efficiency: An experimental study on hybrid cooling approach with paraffin and forced air convection 提高锂离子电池效率：石蜡和强制空气对流混合冷却方法的实验研究

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress

Pub Date : 2024-11-12 DOI: 10.1016/j.tsep.2024.103048

Enis Selcuk Altuntop , Dogan Erdemir , Yüksel Kaplan , Veysel Özceyhan

This article experimentally investigates the application of commercial paraffin for the thermal management of Li-ion battery packs under various operational and design parameters. The performance of paraffin is compared to natural and forced air convection effects without paraffin. In the experiments, battery packs of 12 V, 24 V, and 48 V are utilized. The discharge rates are 1, 2, 3, 4, and 5C. The distance variations between the battery cells for the PCM cooling method are examined at 0.25D, 0.5D, and 1D (D is the diameter of the battery cell). The results indicate that the battery packs with natural air convection exceed the thermal limitations recommended by the battery cell manufacturer. Besides that, forced air convection created undesirable conditions for the long-term use of batteries. The energy efficiency values for hybrid cooling that combines paraffin and forced air are higher than those for forced air convection. The battery packs have demonstrated the best performance in 48 V, 0.5D and 0 m/s case with 97 % efficiency for 4C discharge rate. The lowest efficiency has been seen in 12 V, 0.5D and 0 m/s with 50 % for 5C discharge rate. The lowest temperature difference is observed in 12 V, 0.25D and 0 m/s for 1C discharge rate which is 1.9 °C. The highest temperature difference is spotted in 12 V, 0D, and 0 m/s case for 5C discharge rate which is 32 °C. The highest temperature is 102 °C in 48 V, 0D, and 0 m/s case for 5C discharge rate. The lowest temperature is 24 °C in 24 V, 0.5, and 7.5 m/s case for 1C discharge rate.

本文通过实验研究了商用石蜡在不同运行和设计参数下对锂离子电池组热管理的应用。将石蜡的性能与不使用石蜡的自然对流和强制空气对流效果进行了比较。实验中使用了 12 V、24 V 和 48 V 的电池组。放电速率分别为 1、2、3、4 和 5C。在 PCM 冷却方法中，电池单元之间的距离变化分别为 0.25D、0.5D 和 1D（D 为电池单元的直径）。结果表明，采用自然空气对流的电池组超过了电池芯制造商建议的热限制。此外，强制空气对流为电池的长期使用创造了不良条件。石蜡和强制空气混合冷却的能效值高于强制空气对流的能效值。电池组在 48 V、0.5D 和 0 m/s 的情况下表现最佳，在 4C 放电率下效率为 97%。在电压为 12 V、电流为 0.5D 和流速为 0 m/s 的情况下，效率最低，在 5C 放电速率下为 50%。在 12 V、0.25 D 和 0 m/s 条件下，放电速率为 1 C 时的温差最小，为 1.9 °C。在 12 V、0D 和 0 m/s 条件下，5C 放电速率的温差最大，为 32 °C。在 48 V、0D 和 0 m/s 条件下，5C 放电速率的最高温度为 102 °C。在 24 V、0.5 和 7.5 m/s 条件下，放电速率为 1 C 时的最低温度为 24 °C。

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引用次数: 0

A thermo-economic comparison on new and conventional alternatives of pressurization of CO2 in CCS systems 二氧化碳捕获和封存系统中二氧化碳加压的新型和传统替代方法的热经济比较

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress

Pub Date : 2024-11-10 DOI: 10.1016/j.tsep.2024.103046

S. Khalili, L.Garousi Frashi

The final stage of carbon capture and storage processes involves the pressurization of CO₂ by a suitable method which is conventionally carried out through a series of compressors with intercoolers in between them. In the present study, the idea of liquefying the captured CO₂ is considered. Four different systems for the liquefaction process are evaluated and compared Thermo-economically with the benchmark system of direct carbon dioxide compression. The results indicate that the EPLS system outperforms the others, with a product cost 5.89% lower than the benchmark system. Evaluations show that most of the costs are imposed by the initial compression stage in each system. A detailed investigation of the sensitivity analysis shows that the benchmark and claude systems have the largest dependency on pressure ratio and intercooling temperature, respectively. Additionally, evaluation of the economic parameters indicates that the changes in unit cost of power have the most effect on the benchmark system while the interest rate affects the results of claude and DEBARS more than other options. Detailed evaluations reveal that the EPLS layout has the advantage of less dependency on the changes of operating parameters and on the other hand, the cost of input heat, the maintenance factor, and the generator and evaporator temperatures make a high difference in the final product cost of the DEBARS. Finally, the effect of pressure drops in heat exchangers is investigated and results reveal that the consideration of pressure drops leads to power penalties ranging from 0.97 to 8.52 $/hr in different systems.

碳捕集与封存工艺的最后阶段是采用适当的方法对二氧化碳进行加压，传统的加压方法是通过一系列压缩机和中间冷却器来实现的。本研究考虑了将捕获的二氧化碳液化的想法。对液化过程的四种不同系统进行了评估，并与直接压缩二氧化碳的基准系统进行了热经济学比较。结果表明，EPLS 系统优于其他系统，其产品成本比基准系统低 5.89%。评估表明，每个系统的大部分成本都是由初始压缩阶段造成的。对敏感性分析的详细研究表明，基准系统和克劳德系统分别对压力比和中间冷却温度具有最大的依赖性。此外，对经济参数的评估表明，单位电力成本的变化对基准系统的影响最大，而利率对 claude 和 DEBARS 系统结果的影响大于其他方案。详细评估表明，EPLS 布局的优点是对运行参数变化的依赖性较小，而另一方面，输入热量成本、维护系数以及发电机和蒸发器温度对 DEBARS 最终产品成本的影响很大。最后，研究了热交换器压降的影响，结果表明，在不同的系统中，考虑压降会导致 0.97 至 8.52 美元/小时的功率损失。

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引用次数: 0

Predictive modeling for dynamic heat load in frigid railway roadbeds: An energy-efficient approach 寒冷铁路路基动态热负荷预测模型：节能方法

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress

Pub Date : 2024-11-10 DOI: 10.1016/j.tsep.2024.103049

Tianfei Hu , Liqi Zhao , Tengfei Wang , Zurun Yue , Yifei Yuan

This research presents an innovative approach to dynamic heat load prediction in railway roadbeds situated in cold climates by incorporating the concept of heat load, traditionally used in the building sector. The method facilitates a comprehensive evaluation and energy-efficient control of heating systems in these specialized transportation infrastructures. Utilizing an integrated building simulation toolkit (DeST), a computational model for roadbed micro-elements is established, integrating weather, radiation, and shading models to simulate pertinent environmental factors. Employing the state space method, a thermal module calculates the base temperature of these micro-elements. Subsequent calculations determine the roadbed’s target temperature and temporal heat load. Empirical data from the Harbin-Qiqihar high-speed railway validates the method, revealing strong alignment between computed and measured roadbed temperatures. Heat load peaks at 945 W/m and averages 335 W/m in freezing conditions. The method accounts for thermal hysteresis and variations related to roadbed orientation and depth. Regional statistics show a heat load range of 531 to 1,338 W/m and establish a direct correlation between heat load and latitude. The findings significantly enhance the ability to assess frost damage and design energy-efficient heating plans for railway roadbeds in frigid environments.

这项研究提出了一种创新方法，通过结合传统上用于建筑领域的热负荷概念，对位于寒冷气候条件下的铁路路基进行动态热负荷预测。该方法有助于对这些专用交通基础设施的供热系统进行综合评估和节能控制。利用综合建筑模拟工具包（DeST），建立了路基微元件计算模型，集成了天气、辐射和遮阳模型，以模拟相关的环境因素。热模块采用状态空间法计算这些微元件的基础温度。随后的计算确定了路基的目标温度和时间热负荷。来自哈尔滨-齐齐哈尔高速铁路的经验数据验证了这一方法，显示计算和测量的路基温度高度一致。在冰冻条件下，热负荷峰值为 945 瓦/米，平均为 335 瓦/米。该方法考虑了热滞后以及与路基走向和深度有关的变化。区域统计数据显示热负荷范围为 531 至 1,338 W/m，并确定了热负荷与纬度之间的直接相关性。这些发现大大提高了在寒冷环境中评估冻害和设计铁路路基节能加热计划的能力。

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引用次数: 0