An experimental investigation of an inclined passive wall solar chimney for natural ventilation

Solar Energy ◽  
2014 ◽  
Vol 107 ◽  
pp. 461-474 ◽  
Author(s):  
Rakesh Khanal ◽  
Chengwang Lei
Keyword(s):  
Experimental Investigation ◽  
Natural Ventilation ◽  
Solar Chimney

scholarly journals Experimental Investigation of Thermal Performance of a Solar Chimney Provided with a Porous Absorber Plate

2020 ◽  
Vol 26 (4) ◽  
pp. 1-20
Author(s):  
Bashaar Abdulkareem Hamood ◽  
Mohammed ABDUL RAOUF NIMA
Keyword(s):  
Experimental Investigation ◽  
Thermal Performance ◽  
Natural Ventilation ◽  
Metal Foam ◽  
Weather Condition ◽  
Ventilation Rate ◽  
Incline Angle ◽  
Solar Chimney ◽  
Absorber Plate ◽  
Air Temperatures

  Experimental investigation of the influence of inserting the metal foam to the solar chimney to induce natural ventilation are described and analyzed in this work. To carry out the experimental test, two identical solar chimneys (without insertion of metal foam and with insertion of metal foam) are designed and placed facing south with dimensions of length× width× air gap (2 m× 1 m× 0.2 m). Four incline angles are tested (20o,30o,45o,60o) for each chimney in Baghdad climate condition (33.3o latitude, 44.4o longitude) on October, November, December 2018. The solar chimney performance is investigated by experimentally recording absorber plate and air temperatures and velocity of air. Results indicated that the using metal foam absorber plate lead to reducing the mean temperature of absorber plate by 6.7 °C as a result, the values of chimney outlet air temperature increased. The daily solar chimney efficiency enhanced by 58.7% and the useful energy received also increased. The existence of metal foam caused higher air velocity at the exit and increasing in the ventilation rate that the maximum ventilate rate obtained from the solar chimney is 5.96 1/hr for 27 m3 volume of room at solar irradiance of 730 W/m2   for chimney incline angle of 60o. The results of the experimental work show that the addition of metal foam to the solar chimney as an absorber plate is an efficient method to enhance the characteristics of heat transfer and the thermal performance of the solar chimney in the weather condition of Iraq.

Experimental Investigation of Using Solar Chimney to Induce Natural Ventilation

2014 ◽  
Vol 672-674 ◽  
pp. 109-112 ◽  
Author(s):  
Cai Xia Hao ◽  
Hai Ping Zhang ◽  
Min Xia Hao
Keyword(s):  
Heat Flux ◽  
Experimental Investigation ◽  
Velocity Field ◽  
Boundary Layers ◽  
Natural Ventilation ◽  
Heated Surface ◽  
Experimental Results ◽  
Solar Chimney ◽  
Air Velocity ◽  
Radiant Intensity

The vertical panels of solar chimney have internal dimensions of 2000mm height、1000mm length. Under the condition of heat flux and chimney gap variety, we research chimney interior velocity field. Experimental Results show that airflow increased with chimney gap augmentation, the airflow and air velocity augment with the increase of solar radiant intensity, and air velocity decreases with the increase of solar chimney gap. Air velocity is higher near the heated surfaces than it in the middle chimney. Meanwhile velocity boundary layers form near the heated surface.

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.

Natural-Ventilation Flow in a 3-D Room Fitted With Solar Chimney

2012 ◽  
Author(s):  
B. P. Huynh
Keyword(s):  
Heat Flux ◽  
Flow Pattern ◽  
Natural Ventilation ◽  
Air Flow ◽  
Ventilation Rate ◽  
High Heat Flux ◽  
Solar Chimney ◽  
Solar Heat ◽  
Solar Heat Flux ◽  
Inlet Opening

Natural-ventilation flow induced in a real-sized rectangular-box room fitted with a solar chimney on its roof is investigated numerically, using a commercial CFD (Computational Fluid Dynamics) software package. The chimney in turn is in the form of a parallel channel with one plate being subjected to uniform solar heat flux. Ventilation rate and air-flow pattern through the room are considered in terms of the heat flux for two different locations of the room’s inlet opening. Chien’s turbulence model of low-Reynolds-number K-ε is used in a Reynolds-Averaged Navier-Stokes (RANS) formulation. It is found that ventilation flow rate increases quickly with solar heat flux when this flux is low, but more gradually at higher flux. At low heat flux, ventilation rate is not significantly affected by location of the inlet opening to the room. On the other hand, at high heat flux, ventilation rate varies substantially with the opening’s location. Location of the inlet opening to the room also affects strongly the air-flow pattern. In any case, ample ventilation rate is readily induced by the chimney.

Small and Full-Scale Modeling for the Application of Wall Solar Chimneys

2016 ◽  
Author(s):  
David Park ◽  
Francine Battaglia
Keyword(s):  
Natural Ventilation ◽  
Velocity Ratio ◽  
Thermal Conditions ◽  
Ambient Air ◽  
Full Scale ◽  
Scale Model ◽  
Small Scale ◽  
Solar Chimney ◽  
Window Position ◽  
Pi Theorem

A solar chimney is a natural ventilation technique that has a potential to save energy consumption as well as to maintain the air quality in the building. However, studies of buildings are often challenging due to their large sizes. The objective of the current study was to determine relationships between small- and full-scale solar chimney system models. In the current work, computational fluid dynamics (CFD) was utilized to model different building sizes with a solar chimney system, where the computational model was validated with the experimental study of Mathur et al. The window, which controls entrainment of ambient air, was also studied to determine the effects of window position. Correlations for average velocity ratio and non-dimensional temperature were consistent regardless of window position. Buckingham pi theorem was employed to further non-dimensionalize the important variables. Regression analysis was conducted to develop a mathematical model to predict a relationship among all of the variables, where the model agreed well with simulation results with an error of 2.33%. The study demonstrated that the flow and thermal conditions in larger buildings can be predicted from the small-scale model.

Development of a Predictive Equation for Ventilation in a Wall-Solar Chimney System

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
David Park ◽  
Francine Battaglia
Keyword(s):  
Mathematical Model ◽  
Relative Error ◽  
Natural Ventilation ◽  
Thermal Conditions ◽  
Ambient Air ◽  
Maximum Error ◽  
Scale Model ◽  
Small Scale ◽  
Maximum Relative Error ◽  
Solar Chimney

A solar chimney is a natural ventilation technique that has potential to save energy consumption as well as to maintain the air quality in a building. However, studies of buildings are often challenging due to their large sizes. The objective of this study was to determine the relationships between small- and full-scale solar chimney system models. Computational fluid dynamics (CFD) was employed to model different building sizes with a wall-solar chimney utilizing a validated model. The window, which controls entrainment of ambient air for ventilation, was also studied to determine the effects of window position. A set of nondimensional parameters were identified to describe the important features of the chimney configuration, window configuration, temperature changes, and solar radiation. Regression analysis was employed to develop a mathematical model to predict velocity and air changes per hour, where the model agreed well with CFD results yielding a maximum relative error of 1.2% and with experiments for a maximum error of 3.1%. Additional wall-solar chimney data were tested using the mathematical model based on random conditions (e.g., geometry, solar intensity), and the overall relative error was less than 6%. The study demonstrated that the flow and thermal conditions in larger buildings can be predicted from the small-scale model, and that the newly developed mathematical equation can be used to predict ventilation conditions for a wall-solar chimney.

Enhancement of Gravity Ventilation in Buildings

2017 ◽  
Author(s):  
Magdalena Nakielska ◽  
Krzysztof Pawłowski
Keyword(s):  
Natural Ventilation ◽  
Air Flow ◽  
Electrical Energy ◽  
Climatic Conditions ◽  
Demand Systems ◽  
Solar Chimney ◽  
Correct Operation ◽  
Research Results ◽  
Heat Demand ◽  
Flow Through

Nowadays, people are looking for solutions related to ventilation, cooling or heat demand systems, which would be energy efficient and, at the same time, would not cause the degradation of the surrounding environment. As far as ventilation is concerned, an good solution is a natural ventilation, which improves thermal comfort rooms without increasing the consumption of electrical energy in the building. In order to improve the mode of action of the natural ventilation in the building, one can mount various elements supporting the air flow. One of them is a solar chimney. In order to check the correct operation of a gravity ventilation installation in Poland’s climatic conditions, the measurements was carried out on a test stand on the 3.1 building of UTP University of Science and Technology in Bydgoszcz. The received results show the intensification of the air flow through the room the value between 50% and 150%, depending on a measuring hour (Chen et al. 2003). These research results were compared with the research results received before the installation of the solar chimney on the ducts of the gravity ventilation.

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