Article
Thermodynamics
Zhongbao Liu, Ziyan Wei, Ruonan Teng, Han Sun, Zhipeng Qie
Summary: With the development of the economy, improving energy efficiency and saving energy have become important issues. Combining phase change heat storage material with floor radiation heating is an effective way to improve energy utilization efficiency. This paper introduces a composite phase change heat storage material used in radiant floor heating and conducts experiments on a floor radiation heating system based on heat storage in different environments. The results showed significant improvements in thermal conductivity and heat release time, making this system a promising solution for achieving heating comfort and economy.
APPLIED THERMAL ENGINEERING
(2023)
Article
Construction & Building Technology
Lidi Lu, Jinhua Chen, Tao Su, Xingyu Liu, Yaqi Hu, Qing Luo, Lulin Luo
Summary: This paper proposes a comprehensive thermal resistance and heat capacity (RC) network model in the frequency domain for lightweight radiant floor heating (RFH) coupled with envelopes under intermittent operation. The model is validated by experimental data and provides a theoretical basis for RFH design and energy consumption management.
BUILDING AND ENVIRONMENT
(2022)
Article
Thermodynamics
Barbara Larwa, Silvia Cesari, Michele Bottarelli
Summary: The study aimed to investigate a hydronic radiant floor heating system integrated with macroencapsulated PCM through experimental and numerical analysis of system performance under various conditions. Results showed that high thermal conduction in mortar enhances overall system performance, while coupling technology with PCM containers significantly enhances the effect of wet sand.
Article
Construction & Building Technology
Ali Saberi-Derakhtenjani, Andreas K. Athienitis, Ursula Eicker, Edwin Rodriguez-Ubinas
Summary: Radiant floor systems offer potential for studying and developing energy flexibility strategies for buildings and smart grids. This study compares different control strategies for activating energy flexibility in zones with radiant floor heating systems. The control strategy based on zone air temperature provides higher flexibility for both downward and upward scenarios compared with floor surface and operative temperature controls.
Article
Construction & Building Technology
Lidi Lu, Lulin Luo, Jinhua Chen
Summary: The radiant heat flow rate of the radiant surface is crucial for the design of radiant floor heating and terminal selection. However, the present empirical formula for predicting the radiant heat flow rate has limitations in different room sizes and surface emissivity circumstances. Wall insulation conditions also significantly affect the efficiency of floor radiant heating. By using machine learning algorithms and backward selection method, a two-layer Neural Network model is proven to be accurate and identifies relevant features for a new empirical formula. This updated formula, with independent variables including room depth, weighted radiant surface area, insulation conditions, indoor air temperature, and radiant surface temperature, shows great accuracy with an R-squared value of 0.97 and RMSE of 2.74. The use of non-radiant surfaces with low emissivity as a passive energy-saving technique is proposed, and the updated empirical formula expands its application scenarios, promoting the application of radiant floor heating and new passive techniques.
ENERGY AND BUILDINGS
(2023)
Article
Chemistry, Multidisciplinary
Enrique Angel Rodriguez Jara, Alvaro Ruiz-Pardo, Marta Conde Garcia, Jose Antonio Tenorio Rios
Summary: The study found that woods with the lowest thermal conductivity can be efficiently utilized in radiant floor heating systems worldwide with start-up lag times similar to those of other floorings. There is no universal limit for thermal resistance in flooring, and the current standard limit of 0.15 m(2) K/W lacks objective justification. Climate and construction characteristics are essential factors in the selection of suitable flooring properties.
APPLIED SCIENCES-BASEL
(2022)
Article
Construction & Building Technology
Shengqiang Shi, Abdelatif Merabtine, Rachid Bennacer, Julien Kauffmann
Summary: This study quantitatively and qualitatively analyzes the evaluation of the impact of real moving sun patch on radiant floor heating for thermal comfort consideration. The results show that long exposure to sun patch can lead to indoor overheating and have an impact on thermal sensation and comfort.
BUILDING AND ENVIRONMENT
(2023)
Article
Construction & Building Technology
Dong Liu, Na Liu, Donglin Ren, Xiaozhou Wu, Jun Wang, Yabin Tian, Anjie Hu, Li Wan, Jialan Wen
Summary: This study compared the thermal sensation and physiological responses to a radiant floor heating system between young adults and preschool children. The results showed that preschool children adapt better to the thermal environment and have a higher sensitivity to temperature changes compared to adults.
Article
Construction & Building Technology
Yakup Karakoyun, Ozgen Acikgoz, Bedri Onur Kucukyildirim, Zehra Yumurtaci, Ahmet Selim Dalkilic
Summary: Hydronic radiant heating systems are commonly used in conjunction with low temperature heat sources to provide high energy saving potential and improved thermal comfort. By employing augmentation methods and using nanofluids, heat transfer performance can be enhanced, with experiments showing that adding nanofluids can improve heat transfer efficiency.
ENERGY AND BUILDINGS
(2021)
Article
Construction & Building Technology
Xin Jin, Jingchao Yang, Min Li, Gongsheng Huang, Alvin CK. Lai
Summary: Thermal energy storage has great potential in improving the energy performance of building heating systems. In this study, a novel thermal-stable storage medium, sodium acetate trihydrate-acetamide/modified expanded graphite, was prepared for space heating applications. The leakage protection tests and thermal conductivity measurements showed the superior compatibility and higher thermal conductivity of the novel composite compared to the pristine mixture. The thermal performance evaluations demonstrated that the heat storage and release of the storage medium could effectively reduce temperature fluctuation and improve indoor comfort. Furthermore, the system with the storage medium had a significantly lower operation cost compared to the system without it. Overall, the results suggest that the novel composite is a competitive candidate for heating applications.
BUILDING AND ENVIRONMENT
(2022)
Article
Construction & Building Technology
Xiangfei Kong, Yufan Chang, Man Fan, Han Li
Summary: A novel heating system named low-temperature radiant floor coupled with intermittent stratum ventilation (LTR-ISV) is proposed in this study, and its thermal performance, indoor air quality, energy and exergy performance are compared with conventional radiant floor heating (CRFH) and conventional radiant floor heating with mixing ventilation (CRFH + MV). The results indicate that LTR-ISV has better temperature distribution, thermal sensation, air mixing, and reduced CO2 concentration and airborne transmission risk compared to CRFH and CRFH + MV. The performance coefficient and exergy efficiency of LTR-ISV were also evaluated.
ENERGY AND BUILDINGS
(2023)
Article
Construction & Building Technology
Zhiwei Li, Jili Zhang
Summary: Radiant floor heating (RFH) is an advanced technology that can improve thermal comfort for occupants. This study focuses on developing a control-oriented thermodynamic model and a distributed MPC scheme for large-scale RFH systems with hydraulic coupling. The experiment and simulation results demonstrate that the proposed scheme can achieve hydraulic decoupling between occupants and improve thermal comfort.
BUILDING AND ENVIRONMENT
(2022)
Article
Construction & Building Technology
Oumayma Babaharra, Khadija Choukairy, Said Hamdaoui, Kaoutar Khallaki, Sanaa Hayani Mounir
Summary: The rapid growth of urbanization and the increase of internal comfort requirements negatively impact the environment and energy consumption in the building sector. Providing internal thermal comfort with environmentally friendly techniques is crucial. This study numerically investigates and evaluates the thermal performance of a heated floor incorporating a microencapsulated phase change material. The integration of a PCM in the floor aims to reduce energy consumption and stabilize internal temperature. Parameters such as microcapsules integration, mass fraction, tubes inter-distance, and PCM type are evaluated and discussed.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Thermodynamics
Hongpu Liang
Summary: This study introduces the basic structure and control strategy of ground-source heat pump-floor radiant air conditioning system, and analyzes an experimental room in Xining, Qinghai province. The optimized control strategy proposed in this study can improve thermal comfort and reduce energy consumption.
INTERNATIONAL JOURNAL OF LOW-CARBON TECHNOLOGIES
(2021)
Article
Construction & Building Technology
Ying Zhang, Chenbo Zhao, Thomas Olofsson, Gireesh Nair, Bin Yang, Angui Li
Summary: This paper analyzes the energy use and operating modes of radiant floor heating systems in a cold climate using a church as a case study. The results show that the constant set-point air temperature radiant floor heating aided by a warm air system is the most reliable and provides the best thermal comfort, regardless of outdoor temperature fluctuations.
ENERGY AND BUILDINGS
(2022)
Article
Green & Sustainable Science & Technology
Cameron Bracken, Nathalie Voisin, Casey D. Burleyson, Allison M. Campbell, Z. Jason Hou, Daniel Broman
Summary: This study presents a methodology and dataset for examining compound wind and solar energy droughts, as well as the first standardized benchmark of energy droughts across the Continental United States (CONUS) for a 2020 infrastructure. The results show that compound wind and solar droughts have distinct spatial and temporal patterns across the CONUS, and the characteristics of energy droughts are regional. The study also finds that compound high load events occur more often during compound wind and solar droughts than expected.
Article
Green & Sustainable Science & Technology
Ning Zhang, Yanghao Yu, Jiawei Wu, Ershun Du, Shuming Zhang, Jinyu Xiao
Summary: This paper provides insights into the optimal configuration of CSP plants with different penetrations of wind power by proposing an unconstrained optimization model. The results suggest that large solar multiples and TES are preferred in order to maximize profit, especially when combined with high penetrations of wind and photovoltaic plants. Additionally, the study demonstrates the economy and feasibility of installing electric heaters (EH) in CSP plants, which show a linear correlation with the penetration of variable energy resources.
Article
Green & Sustainable Science & Technology
M. Szubel, K. Papis-Fraczek, S. Podlasek
Article
Green & Sustainable Science & Technology
J. Silva, J. C. Goncalves, C. Rocha, J. Vilaca, L. M. Madeira
Summary: This study investigated the methanation of CO2 in biogas and compared two different methanation reactors. The results showed that the cooled reactor without CO2 separation achieved a CO2 conversion rate of 91.8%, while the adiabatic reactors achieved conversion rates of 59.6% and 67.2%, resulting in an overall conversion rate of 93.0%. Economic analysis revealed negative net present worth values, indicating the need for government monetary incentives.
Article
Green & Sustainable Science & Technology
Yang Liu, Yonglan Xi, Xiaomei Ye, Yingpeng Zhang, Chengcheng Wang, Zhaoyan Jia, Chunhui Cao, Ting Han, Jing Du, Xiangping Kong, Zhongbing Chen
Summary: This study investigated the effect of using nanofiber membrane composites containing Prussian blue-like compound nanoparticles (PNPs) to relieve ammonia nitrogen inhibition of rural organic household waste during high-solid anaerobic digestion and increase methane production. The results showed that adding NMCs with 15% PNPs can lower the concentrations of volatile fatty acids and ammonia nitrogen, and increase methane yield.
Article
Green & Sustainable Science & Technology
Zhong Ge, Xiaodong Wang, Jian Li, Jian Xu, Jianbin Xie, Zhiyong Xie, Ruiqu Ma
Summary: This study evaluates the thermodynamic, exergy, and economic performance of a double-stage organic flash cycle (DOFC) using ten eco-friendly hydrofluoroolefins. The influences of key parameters on performance are analyzed, and the advantages of DOFC over single-stage type are quantified.
Article
Green & Sustainable Science & Technology
Nicolas Kirchner-Bossi, Fernando Porte-Agel
Summary: This study investigates the optimization of power density in wind farms and its sensitivity to the available area size. A novel genetic algorithm (PDGA) is introduced to optimize power density and turbine layout. The results show that the PDGA-driven solutions significantly reduce the levelized cost of energy (LCOE) compared to the default layout, and exhibit a convex relationship between area and LCOE or power density.
Article
Green & Sustainable Science & Technology
Chunxiao Zhang, Dongdong Li, Lin Wang, Qingpo Yang, Yutao Guo, Wei Zhang, Chao Shen, Jihong Pu
Summary: In this study, a novel reversible liquid-filled energy-saving window that effectively regulates indoor solar radiation heat gain is proposed. Experimental results show that this window can effectively reduce indoor temperature during both summer and winter seasons, while having minimal impact on indoor illuminance.
Article
Green & Sustainable Science & Technology
Alessandro L. Aguiar, Martinho Marta-Almeida, Mauro Cirano, Janini Pereira, Leticia Cotrim da Cunha
Summary: This study analyzed the Brazilian Equatorial Shelf using a high-resolution ocean model and found significant tidal variations in the area. Several hypothetical barrages were proposed with higher annual power generation than existing barrages. The study also evaluated the installation effort of these barrages.
Article
Green & Sustainable Science & Technology
Francesco Superchi, Nathan Giovannini, Antonis Moustakis, George Pechlivanoglou, Alessandro Bianchini
Summary: This study focuses on the optimization of a hybrid power station on the Tilos island in Greece, aiming to increase energy export and revenue by optimizing energy fluxes. Different scenarios are proposed to examine the impact of different agreements with the grid operator on the optimal solution.
Article
Green & Sustainable Science & Technology
Peimaneh Shirazi, Amirmohammad Behzadi, Pouria Ahmadi, Sasan Sadrizadeh
Summary: This research presents two novel energy production/storage/usage systems to reduce energy consumption and environmental effects in buildings. A biomass-fired model and a solar-driven system integrated with photovoltaic thermal (PVT) panels and a heat pump were designed and assessed. The results indicate that the solar-based system has an acceptable energy cost and the PVT-based system with a heat pump is environmentally superior. The biomass-fired system shows excellent efficiency.
Article
Green & Sustainable Science & Technology
Zihao Qi, Yingling Cai, Yunxiang Cui
Summary: This study aims to investigate the operational characteristics of the solar-ground source heat pump system (SGSHPS) in Shanghai under different operation modes. It concludes that tandem operation mode 1 is the optimal mode for winter operation in terms of energy efficiency.
Article
Green & Sustainable Science & Technology
L. Bartolucci, S. Cordiner, A. Di Carlo, A. Gallifuoco, P. Mele, V. Mulone
Summary: Spent coffee grounds are a valuable biogenic waste that can be used as a source of biofuels and valuable chemicals through pyrolysis and solvent extraction processes. The study found that heavy organic bio-oil derived from coffee grounds can be used as a carbon-rich biofuel, while solvent extraction can extract xantines and p-benzoquinone, which are important chemicals for various industries. The results highlight the promising potential of solvent extraction in improving the economic viability of coffee grounds pyrolysis-based biorefineries.
Article
Green & Sustainable Science & Technology
Luiza de Queiroz Correa, Diego Bagnis, Pedro Rabelo Melo Franco, Esly Ferreira da Costa Junior, Andrea Oliveira Souza da Costa
Summary: Building-integrated photovoltaics, especially organic solar technology, are important for reducing greenhouse gas emissions in the building sector. This study analyzed the performance of organic panels laminated in glass in a vertical installation in Latin America. Results showed that glass lamination and vertical orientation preserved the panels' performance and led to higher energy generation in winter.
Article
Green & Sustainable Science & Technology
Zhipei Hu, Shuo Jiang, Zhigao Sun, Jun Li
Summary: This study proposes innovative fin arrangements to enhance the thermal performance of latent heat storage units. Through optimization of fin distribution and prediction of transient melting behaviors, it is found that fin structures significantly influence heat transfer characteristics and melting behaviors.