scholarly journals SIMULATION STUDY ON SOLAR ASSISTED VENTILATION SYSTEMS : Unsteady-state simulation of a detached building with solar chimney using weather data

2004 ◽  
Vol 69 (577) ◽  
pp. 19-26 ◽  
Author(s):  
Zoltan ADAM ◽  
Toshio YAMANAKA ◽  
Hisashi KOTANI
Keyword(s):  
Simulation Study ◽  
Assisted Ventilation ◽  
Weather Data ◽  
Unsteady State ◽  
Solar Chimney ◽  
Ventilation Systems

scholarly journals Solar Chimney Applications in Buildings

Encyclopedia ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 409-422
Author(s):  
Haihua Zhang ◽  
Yao Tao ◽  
Long Shi
Keyword(s):  
Natural Ventilation ◽  
Energy System ◽  
Assisted Ventilation ◽  
Building Envelope ◽  
Building Structures ◽  
Solar Chimney ◽  
Climate Conditions ◽  
And Performance ◽  
Modern Building ◽  
Ventilation Systems

A solar chimney is a renewable energy system used to enhance the natural ventilation in a building based on solar and wind energy. It is one of the most representative solar-assisted passive ventilation systems attached to the building envelope. It performs exceptionally in enhancing natural ventilation and improving thermal comfort under certain climate conditions. The ventilation enhancement of solar chimneys has been widely studied numerically and experimentally. The assessment of solar chimney systems based on buoyancy ventilation relies heavily on the natural environment, experimental environment, and performance prediction methods, bringing great difficulties to quantitative analysis and parameterization research. With the increase in volume and complexity of modern building structures, current studies of solar chimneys have not yet obtained a unified design strategy and corresponding guidance. Meanwhile, combining a solar chimney with other passive ventilation systems has attracted much attention. The solar chimney-based integrated passive-assisted ventilation systems prolong the service life of an independent system and strengthen the ventilation ability for indoor cooling and heating. However, the progress is still slow regarding expanded applications and related research of solar chimneys in large volume and multi-layer buildings, and contradictory conclusions appear due to the inherent complexity of the system.

scholarly journals Simulation Study of a Membrane Reactor for Ultrapure Hydrogen Recovery from Methanol Steam Reforming Reaction under Periodic Steady-State

2018 ◽  
Vol 13 (2) ◽  
pp. 275
Author(s):  
Lemnouer Chibane
Keyword(s):  
Steady State ◽  
Simulation Study ◽  
Steam Reforming ◽  
Membrane Reactor ◽  
Operating Conditions ◽  
Methanol Steam Reforming ◽  
Pure Hydrogen ◽  
Unsteady State ◽  
Hydrogen Recovery ◽  
Periodic Steady State

Steam reforming of methanol over Cu/ZnO/Al2O3 catalyst was theoretically studied under created unsteady state. A mathematical approach was proposed to evaluate the effect of periodic inputs on reactor performance. The efficacy of the periodic separating reactor in term of pure hydrogen and of methanol conversion was measured during the reaction of methanol steam reforming. The obtained results showed that under certain operating conditions the periodic operation can be used advantageously to increase the reactor ability up to a level higher than the maximal steady-state. Moreover, our findings showed that the pumping of hydrogen through the membrane was stimulated by the effect of periodic operations. The predicted results suggested that the created unsteady state mode by using a square wave function could give the better performances compared to the sinusoidal mode. Copyright © 2018 BCREC Group. All rights reservedReceived: 15th July 2017; Revised: 26th November 2017; Accepted: 8th December 2017; Available online: 11st June 2018; Published regularly: 1st August 2018How to Cite: Chibane, L. (2018). Simulation Study of a Membrane Reactor for Ultrapure Hydrogen Recovery from Methanol Steam Reforming Reaction under Periodic Steady-State. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (2): 275-285 (doi:10.9767/bcrec.13.2.1340.275-285) 

Solar Chimney and Turbine-Assisted Ventilation System

2021 ◽  
pp. 139-169
Author(s):  
Ling Leh Sung ◽  
Mohd. Suffian bin Misran ◽  
Md. Tarek Ur Rahman Erin ◽  
Md. Mizanur Rahman
Keyword(s):  
Ventilation System ◽  
Assisted Ventilation ◽  
Solar Chimney

scholarly journals INVESTIGATION OF THE ENERGY RECOVERY POTENTIALS IN VENTILATION SYSTEMS IN DIFFERENT CLIMATES

2018 ◽  
Vol 16 (2) ◽  
pp. 203 ◽  
Author(s):  
Miklos Kassai ◽  
Laszlo Poleczky ◽  
Laith Al-Hyari ◽  
Laszlo Kajtar ◽  
Jozsef Nyers
Keyword(s):  
Energy Recovery ◽  
Heat Recovery ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Weather Data ◽  
High Definition ◽  
Engineering Practices ◽  
Available Information ◽  
Different Climates ◽  
Ventilation Systems

The aim of this research study was to investigate the energy recovery potentials in ventilation systems under different climatic conditions. The well-known heating degree day from the literature was updated using the weather data of cities with different climates from the past 40 years. As the novelty of this research with the developed procedure drawn up in this study, the energetic possibilities of heat recovery under various climate and operating conditions may be examined in more detail and more realistically than with the methods and available information of current engineering practices. To achieve this long-term and high definition the weather data of several cities are processed in order to evaluate the possibilities of heat recovery on a daily and annual basis.

scholarly journals Análisis teórico de una chimenea solar con tres canales de flujo de aire

2019 ◽  
pp. 13-19
Author(s):  
Angel Tlatelpa-Becerro ◽  
Ramiro Rico-Martínez ◽  
Gustavo Urquiza-Beltrán ◽  
Elva Lilia Reynoso-Jardón
Keyword(s):  
Natural Ventilation ◽  
Single Channel ◽  
Residential Buildings ◽  
Air Flow ◽  
Tropical Region ◽  
Solar Chimney ◽  
Climatic Zones ◽  
The Cost ◽  
Energy Balances ◽  
Ventilation Systems

A solar chimney configuration consisting of three air flow channels divided by two metallic plate, placed in the center of the chimney between two acrylic covers, leading to symmetric air flow, is proposed as an alternative for the design of natural ventilation systems for buildings in tropical and subtropical climatic zones The solar chimney dimensions are 2.0 m height, 1.0 m width, and gap between channels of 0.30 m. These dimensions are appropriate for the design of ventilation systems for residential buildings in central México. A Numerical simulation using the global mass and energy balances in steady state was utilized to evaluate the efficacy of the proposed configuration. The temperature profiles, calculated for a typical hot day in a tropical region, reveal that the configuration is more efficient than the single channel chimney, achieving thermal efficiency values near 75%. This solar chimney configuration can be used with better results than the traditional design as an alternative for natural ventilation systems in residential buildings without a significant increase in the cost of the residence investment.

Unsteady state of a solar chimney power plant accoupled with a turbine: case study

2018 ◽  
Vol 16 (2) ◽  
pp. 244-255
Author(s):  
Ahmed Ayadi ◽  
Haythem Nasraoui ◽  
Zied Driss ◽  
Abdallah Bouabidi ◽  
Mohamed Salah Abid
Keyword(s):  
Power Plant ◽  
Unsteady State ◽  
Solar Chimney ◽  
Solar Chimney Power Plant

scholarly journals Computational Analysis of a Lecture Room Ventilation System

2020 ◽  
Author(s):  
Abayomi Layeni ◽  
Collins Nwaokocha ◽  
Olalekan Olamide ◽  
Solomon Giwa ◽  
Samuel Tongo ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Minimum Cost ◽  
Solar Chimney ◽  
Lecture Room ◽  
Room Ventilation System ◽  
Ventilation Systems

The level of Indoor Air Quality (IAQ) has become a big topic of research, and improving it using passive ventilation methods is imperative due to the cost saving potentials. Designing lecture buildings to use less energy or Zero Energy (ZE) has become more important, and analysing buildings before construction can save money in design changes. This research analyses the performance (thermal comfort [TC]) of a lecture room, investigate the use of passive ventilation methods and determine the energy-saving potential of the proposed passive ventilation method using Computational Fluid Dynamics (CFD). Results obtained showed that air change per hour at a wind velocity of 0.05 m/s was 3.10, which was below standards. Therefore, the lecture hall needs external passive ventilation systems (Solar Chimney [SC]) for improved indoor air quality at minimum cost. Also, it was observed that the proposed passive ventilation (SC) system with the size between 1 and 100 m3, made an improvement upon the natural ventilation in the room. There was a 66.69% increase after 10 years in the saving of energy and cost using Solar Chimney as compared to Fans, which depicts that truly energy and cost were saved using passive ventilation systems rather than mechanical ventilation systems.

scholarly journals Effectiveness of a Real-Time Ventilation Feedback Device for Guiding Adequate Minute Ventilation: A Manikin Simulation Study

Medicina ◽  
2020 ◽  
Vol 56 (6) ◽  
pp. 278
Author(s):  
Sejin Heo ◽  
Sun Young Yoon ◽  
Jongchul Kim ◽  
Hye Seung Kim ◽  
Kyunga Kim ◽  
...  
Keyword(s):  
Real Time ◽  
Simulation Study ◽  
Washout Period ◽  
Primary Outcome ◽  
Positive Pressure Ventilation ◽  
Minute Ventilation ◽  
Assisted Ventilation ◽  
Secondary Outcome ◽  
Positive Pressure ◽  
Medical Providers

Background and objectives: It is often challenging even for skilled rescuers to provide adequate positive pressure ventilation consistently. This study aimed to investigate the effectiveness of a newly developed real-time ventilation feedback device (RTVFD) that estimates tidal volume (TV) and ventilation interval (VI) in real time. Materials and methods: We conducted a randomised, crossover, manikin simulation study. A total of 26 medical providers were randomly assigned to the RTVFD-assisted ventilation (RAV) first group (n = 13) and the non-assisted ventilation (NV) first group (n = 13). Participants provided ventilation using adult and paediatric bag valves (BVs) for 2 min each. After a washout period, the simulation was repeated by exchanging the participants’ groups. Results: The primary outcome was optimal TV in the RAV and NV groups using adult and paediatric BVs. A secondary outcome was optimal VI in the RAV and NV groups using adult and paediatric BVs. The proportions of optimal TV values were higher for the RAVs when using both adult and paediatric BVs (adult BV: 47.29% vs. 18.46%, p < 0.001; paediatric BV: 89.51% vs. 72.66%, p < 0.001) than for the NVs. The proportions of optimal VI were significantly higher in RAVs when using both adult and paediatric BVs than that in NVs (adult BV: 95.64% vs. 50.20%, p < 0.001; paediatric BV: 95.83% vs. 57.14%, p < 0.001). Additionally, we found that with paediatric BVs, the simulation had a higher OR for both optimal TV (13.26; 95% CI, 9.96–17.65; p < 0.001) and VI (1.32; 1.08–1.62, p = 0.007), regardless of RTVFD use. Conclusion: Real-time feedback using RTVFD significantly improves the TV and VI in both adult and paediatric BVs in a manikin simulation study.

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