International Journal of Low-carbon Technologies最新文献_第5页

Diurnal Characterization of the Atmospheric Urban Heat Island over Urban Hot Agglomerations 城市热点地区大气城市热岛的日特征

IF 2.3 4区工程技术

International Journal of Low-carbon Technologies Pub Date : 2023-03-20 DOI: 10.1093/ijlct/ctad025

B. Sayad, Y. Menni, Ayman Imam, Ahmad Fallatah, Kamil Faisal, A. M. Abed, H. Alhubashi, I. Hegazy

{"title":"Diurnal Characterization of the Atmospheric Urban Heat Island over Urban Hot Agglomerations","authors":"B. Sayad, Y. Menni, Ayman Imam, Ahmad Fallatah, Kamil Faisal, A. M. Abed, H. Alhubashi, I. Hegazy","doi":"10.1093/ijlct/ctad025","DOIUrl":"https://doi.org/10.1093/ijlct/ctad025","url":null,"abstract":"\u0000 The urban heat island (UHI) is a physical climatic phenomenon, its effects in the built-up areas can be observed in terms of air temperatures above the atmosphere, as well as in terms of thermal comfort under the urban canopy. This study aims to carry out a diurnal characterization of the atmospheric urban heat island over the agglomeration of Guelma, Algeria during summertime. The characterization is organized into three main steps. First, quantifying the UHI intensity. Second, highlighting the factors contributing to affect the thermal environment in downtown Guelma and fianly, defining an appropriate scale to measure it over Gualma’s agglomeration of Guelma. The UHI quantification was done by calculating the positive differences of urban temperatures in daytime based on in-situ approach and static approach. The results indicate that the maximum daily difference reached 4.8°C to 5.1°C with a positive difference of 6.1° at 10:00 a.m. and 6.4°C at noon, which means that Guelma’s agglomeration is affected by the atmospheric urban heat island phenomenon. Depending on the difference of urban temperatures, we have defined appropriate scale to quantify the intensity of UHI phenomenon over Guelma’s agglomeration: ${UHI}_{intensity}=0.3688vectimes Delta {T}_{boldsymbol{urb}}+3.3157.$","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43033852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of Solar Powered Sorption Cooling and Heating Systems to Supply Hospital’s Thermal Requirements in Pandemic Periods 太阳能吸收式冷热系统在流行病期间满足医院热需求的研究

IF 2.3 4区工程技术

International Journal of Low-carbon Technologies Pub Date : 2023-03-20 DOI: 10.1093/ijlct/ctad026

Bilsay Pastakkaya

{"title":"Investigation of Solar Powered Sorption Cooling and Heating Systems to Supply Hospital’s Thermal Requirements in Pandemic Periods","authors":"Bilsay Pastakkaya","doi":"10.1093/ijlct/ctad026","DOIUrl":"https://doi.org/10.1093/ijlct/ctad026","url":null,"abstract":"\u0000 In pandemic periods such as COVID-19, economic and sociological problems threaten human life and public order on a global scale. In these periods, the use of solar powered heating-cooling systems to meet the thermal needs of the hospitals and to provide the thermal comfort conditions offer important solutions for the elimination of technical, economic and environmental problems related to energy supply. In this study, covering the heating, cooling and hot water supply of a sample hospital building for the three largest cities of Turkey with a novel solar powered Li-Cl absorption heat pump system was investigated using the TRNSYS simulation program. The use of a unique NH3-H2O resorption system as a solar powered auxiliary system was also investigated. It was determined that the total annual hot water and cooling needs of the hospital buildings in all three provinces are supplied almost completely with the solar energy powered system without compromising the hygiene and thermal comfort of the occupants and the average annual solar fraction of total heating demands are calculated as 50%, 54% and 65% for İstanbul, Ankara and İzmir, respectively. In addition, depending on the use of solar energy, it has been observed that annually 126 tons of CO2 emissions were saved and an economic saving of 524 375 TL was achieved in total. Considering the problems about the energy supply during the epidemic periods, it was concluded that meeting the energy requirements of hospitals with clean, renewable and independent energy source will provide significant benefits to the countries.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46464722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A case study on the design and development of solar food cooking system with a PCM as a heat storage unit PCM作为储热单元的太阳能食品烹饪系统的设计与开发案例研究

IF 2.3 4区工程技术

International Journal of Low-carbon Technologies Pub Date : 2023-03-18 DOI: 10.1093/ijlct/ctad002

Usha Pawar, K. Bhole, Ankit D. Oza, H. Panchal, Mohammad Asif Shah, Mustafa Musa Jaber

{"title":"A case study on the design and development of solar food cooking system with a PCM as a heat storage unit","authors":"Usha Pawar, K. Bhole, Ankit D. Oza, H. Panchal, Mohammad Asif Shah, Mustafa Musa Jaber","doi":"10.1093/ijlct/ctad002","DOIUrl":"https://doi.org/10.1093/ijlct/ctad002","url":null,"abstract":"\u0000 This study presents the design and fabrication of an urban solar food cooking system with a phase change material (PCM) as a heat storage tank. The effort has been taken to test the system experimentally and explore its thermal performance under actual climatic conditions of Mumbai, India. The solar heat energy is stored in the tank using commercial grade Erythritol as PCM in current research work. A heat exchanger is well designed and fabricated to regulate the flow of solar heat energy from the storage tank to the cooking vessel, similar to the domestic Liquefied Petroleum Gas (LPG) cooking system. This solar cooker is designed to cook food twice a day for four family members (Equivalent to the energy of 5000 KJ). Cooking experiments were conducted on 19th April 2019 for the afternoon and evening slots with rice and potato as cooking loads, respectively. The time taken for cooking rice and potato are from 12:30 pm to 12:52 pm (22 minute) and from 05:30 pm to 05:59 pm (29 minutes), respectively. The heat transfer rate was also observed at different storage tanks and cooking unit points. The experiments show cooking is possible twice a day and considered as convenient as domestic LPG stoves. Furthermore, it was found that comparatively less time was required for cooking food than the other existing solar cookers.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49369713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

CFD Analysis of gravity-fed drag-type in-pipe water turbine to determine the optimal deflector-to-turbine position 对重力式拖曳式管道水轮机进行CFD分析，确定最优导流器到水轮机位置

IF 2.3 4区工程技术

International Journal of Low-carbon Technologies Pub Date : 2023-03-18 DOI: 10.1093/ijlct/ctac138

Shishir Gautam, Ashish Sedai, Rabin Dhakal, B. Sedai, S. Pol

{"title":"CFD Analysis of gravity-fed drag-type in-pipe water turbine to determine the optimal deflector-to-turbine position","authors":"Shishir Gautam, Ashish Sedai, Rabin Dhakal, B. Sedai, S. Pol","doi":"10.1093/ijlct/ctac138","DOIUrl":"https://doi.org/10.1093/ijlct/ctac138","url":null,"abstract":"\u0000 In-pipe hydroelectric power generation is a relatively new clean energy power generation technology. This new clean energy technology has been identified to be feasible after successful commercial installation in different parts of the world. Several researchers worldwide have studied the optimal turbine type, the optimal number of blades in turbine, introduction of suitable deflector, etc. for this technology. However, the effect of the turbine’s position relative to the upstream deflector on its performance has not been studied so far. This research encompasses a numerical study of the in-pipe hydroelectric power generation turbine to identify the optimal position of the turbine from the deflector. The study was performed for a 160 mm diameter pipeline and a 126 mm turbine height. The research aims to predict the behavior of larger diameter pipelines for commercial installation based on the result obtained from this study. The numerical study was performed for a hollow-type drag turbine at 6 different rotational speeds and 10 different turbine positions. The results suggest that the performance characteristics of drag-type turbine are erratic, thus leaving little space to draw a firm conclusion about the turbine’s performance. However, there was an increase in pressure difference, head, and available theoretical power with the increase in rotational speed for all the positions. It was also found that such turbines were generally more efficient at slightly higher rotational speeds, i.e. speed greater than 40 rad/s, and at about the distance of 0.65D (where D is the pipe diameter) between deflector’s eye and turbine.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47753241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on the optimization strategy of offshore wind power 海上风电优化策略研究

IF 2.3 4区工程技术

International Journal of Low-carbon Technologies Pub Date : 2023-03-13 DOI: 10.1093/ijlct/ctad024

Jing Wang, Xiongfei Wei, Ronaldo Juanatas

引用次数: 1

Lithium-ion battery equalization circuit and control strategy for photovoltaic energy storage applications 用于光伏储能应用的锂离子电池均衡电路和控制策略

IF 2.3 4区工程技术

International Journal of Low-carbon Technologies Pub Date : 2023-03-08 DOI: 10.1093/ijlct/ctad017

Haiyan Yao, Aung Thinzar

{"title":"Lithium-ion battery equalization circuit and control strategy for photovoltaic energy storage applications","authors":"Haiyan Yao, Aung Thinzar","doi":"10.1093/ijlct/ctad017","DOIUrl":"https://doi.org/10.1093/ijlct/ctad017","url":null,"abstract":"\u0000 Solar photovoltaic (PV) is considered a very promising technology, and PV-lithium-ion battery energy storage is widely used to obtain smoother power output. In this paper, we propose a battery equalization circuit and control strategy to improve the performance of lithium-ion batteries. In the equalization circuit, the passive equalization and active equalization circuits are combined, and the active equalization circuit used is simple and has high performance, while in the equalization strategy, since the system works 24h a day, the equalization speed is sacrificed to obtain a smaller temperature rise by adjusting the duty cycle of the passive equalization metal-oxide-semiconductor field-effect transistors (MOSFETs), and by calculating the state of charge (SOC) instead of the voltage to obtain better performance. The proposed circuit and strategy can not only achieve the goal of battery equalization, while turn on 4 batteries at the same time and the temperature rise of passive equalization is only 1°C for about 1.5h, compared with the traditional equalization control strategy with 8mV voltage error, the proposed strategy is only 3mV, which has better performance.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46817669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Location of the phase-change material (PCM) layer on thermal performance of light-weight walls 相变材料(PCM)层位置对轻量化墙体热工性能的影响

IF 2.3 4区工程技术

International Journal of Low-carbon Technologies Pub Date : 2023-02-16 DOI: 10.1093/ijlct/ctac096

Shuhan Liu, Jiahui Wang, Li Meng, Chenxi Hu, Xi Meng

{"title":"Location of the phase-change material (PCM) layer on thermal performance of light-weight walls","authors":"Shuhan Liu, Jiahui Wang, Li Meng, Chenxi Hu, Xi Meng","doi":"10.1093/ijlct/ctac096","DOIUrl":"https://doi.org/10.1093/ijlct/ctac096","url":null,"abstract":"\u0000 Light-weight materials are commonly used in high-rise buildings to reduce the building weight, but their thermal inertia will increase the fluctuation of air-conditioning and heating load and reduce indoor thermal comfort. Phase-Change Material (PCM) is employed to improve the thermal behavior by latent thermal storage, but its location has the obvious impact on the thermal behavior improvement of the light-weight wall. According to this condition, by taking the common multi-layer wall as a reference, three walls were built with different locations of the PCM layer, including locating the PCM layer in inner side, locating the PCM layer in outer side, and distributing PCM uniformly into foamed concrete. The dynamic heat transfer model with the phase change had built and verified by an experiment. Numerical results showed locating the PCM layer in inner side is the best in three locations and followed by distributing PCM uniformly into foamed concrete, while locating the PCM layer in outer side is the worst in the spite of the high liquid fraction variation. Locating the PCM layer in inner side can lower the attenuation factor by 101.25% and 33.87%, increase the delay time by 40.00% and 17.14%, reduced by the peak heat flow by 47.69% and 17.28%, compared to locating the PCM layer in outer side and distributing PCM into foamed concrete uniformly.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45771770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Facilitating Greenhouse Gas Emissions Reduction via Photovoltaic Site Characterisation and Deployment in Jeddah, Saudi Arabia 通过沙特阿拉伯吉达的光伏发电场特征化和部署促进温室气体减排

IF 2.3 4区工程技术

International Journal of Low-carbon Technologies Pub Date : 2023-02-16 DOI: 10.1093/ijlct/ctac099

Fahed A. Aloufi, Riyadh F. Halawani

引用次数: 0

Investigation and Thermo-economic analysis of solar condensation refrigeration 太阳能冷凝制冷的研究与热经济分析

IF 2.3 4区工程技术

International Journal of Low-carbon Technologies Pub Date : 2023-02-16 DOI: 10.1093/ijlct/ctac103

A. Abed, Salema K. Hadrawi, G. Smaisim, A. F. Muftah, F. Jahanbin

引用次数: 2

Evaluating parallelized support vector regression and nearest neighbor regression with different input variations for estimating daily global solar radiation of the humid subtropical region in China 不同输入变化下并行支持向量回归和最近邻回归估算中国湿润亚热带地区日全球太阳辐射

IF 2.3 4区工程技术

International Journal of Low-carbon Technologies Pub Date : 2023-02-08 DOI: 10.1093/ijlct/ctad005

Xiang Yu

{"title":"Evaluating parallelized support vector regression and nearest neighbor regression with different input variations for estimating daily global solar radiation of the humid subtropical region in China","authors":"Xiang Yu","doi":"10.1093/ijlct/ctad005","DOIUrl":"https://doi.org/10.1093/ijlct/ctad005","url":null,"abstract":"\u0000 Indirectly estimating global solar radiation is strongly nonlinear and needs to be addressed by machine learning. Sequentially developing a machine learning model can be very time consuming. Moreover, whether and how the exogenous meteorological, geographical, and temporal variables affect regression accuracy still hasn’t been well understood. This paper evaluates parallelized support vector regression (SVR) and nearest neighbor regression (NNR) models for estimating daily global solar radiation of the humid subtropical region in China using existing Python libraries on a multi-core central processing unit (CPU) and a graphical processing unit (GPU). Seven input variations are studied. Two variations are commonly adopted in literature, four variations contain meteorological, geographical, and/or temporal features with bounded Pearson correlation coefficients (PCCs), and the other variation simply include all the available features. Experimental results demonstrate that: SVR and NNR are equally powerful for nonlinear regression, and the variation comprising features with absolute PCCs no less than 0.3 (i.e. just all the meteorological features) is able to achieve most accurate estimation; the GPU-parallelized SVR model can accelerate parameter calibration and prediction; compared with the CPU-parallelized and GPU-parallelized SVR models, the GPU-parallelized NNR model is much more efficient and rather more scalable with the increment of the number of data samples; and the CPU-parallelized NNR model consumes quite less parameter calibration time than the GPU-parallelized NNR model, owing to different methods adopted for determining distances and significant time wasted by the GPU-parallelized NNR model on repeatedly calculating required information during crossvalidation.","PeriodicalId":14118,"journal":{"name":"International Journal of Low-carbon Technologies","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42281446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0