Experimental and Theoretical Investigation of Performance of a Solar Chimney Model, Part I: Experimental Investigation

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Essaied M Shuia ◽  
Bashir H Arebi ◽  
Ibrahim A abuashe
Keyword(s):  
Experimental Data ◽  
Wind Speed ◽  
Solar Radiation ◽  
Air Temperature ◽  
Solar Collector ◽  
Experimental Results ◽  
Internal Diameter ◽  
Solar Chimney ◽  
Air Velocity ◽  
Collector Temperature

This paper presents the experimental data that was collected from small pilot solar chimney. The experimental data together with ambient conditions are used to evaluate the performance and study the behavior of the solar chimney; this data will be used for comparison with theoretical models in another paper [part II). The solar chimney prototype was designed and constructed at the Subrata Faculty of Engineering-Libya. The data were collected over several days of June 2011. The solar chimney system contains two main components; the solar collector and the solar chimney. The solar collector root‘ has a circular area of126 m3, the solar chimney is a PVC tube with internal diameter of 0.2 m and the total height of chimney is 9.3 m. The measurements include the intensity of solar radiation inside/outside the collector, temperature and velocity of air at the entrance of the chimney, temperature and speed of wind outside the collector, temperature of the ground inside collector al1d temperature measurements of air at speci?c points at different levels throughout the collector. Solar irradiance was found to affect the chimney temperature and subsequently affects chimney air velocity. The experimental results showed that temperature differences of (30 - 45°C) were recorded between the ambient temperature and that of air inside the chimney in the middle of the day, where the highest air temperature of 73.4°C was recorded at the entrance of the solar chimney. The maximum air velocity of 3.6 m/s was recorded inside the solar chimney at noon on 9 June. Wind speed outside the collector had a small effect on the speed of the air inside the chimney and tends to change slightly, hence, can neglect influence of wind speed on the performance of the system. Also the experimental results indicate that such type of system can trap a suf?cient amount of solar radiation, which elevates the air temperature to a suf?cient value able to generate enough air ?ow to operate a wind turbine to produce electricity; this means the solar chimney system for electricity production can work in the north-western part of Libya in the summer time at least.

scholarly journals The Effect of Solar Chimney Dimensions on its Performance in Nasiriya City Weather Conditions

2018 ◽  
Vol 7 (4.19) ◽  
pp. 824
Author(s):  
Rafid M. Hannun ◽  
Hussein Togun ◽  
Mohammed H. Khalaf ◽  
Tariq M. Abed
Keyword(s):  
Solar Radiation ◽  
Solar Collector ◽  
Numerical Study ◽  
Weather Conditions ◽  
Ambient Air ◽  
Previous Literature ◽  
Solar Chimney ◽  
Air Velocity ◽  
Analytical Results ◽  
Air Intake

In this study, a numerical study was carried out on the effect of the solar chimney dimensions on its performance. Five different models of solar chimney were studied in terms of the diameter of the solar collector, the height of the air intake entrance of the collector and the height of the solar chimney. The five models were compared with others according to the conditions surrounding the solar chimney. The study showed that the increase in the dimensions of the solar chimney increases the utilized energy and the external air velocity is inversely proportional to the performance of the solar chimney due to increasing the thermal losses from the collector. The results showed also that increasing the temperature of the ambient air and the solar radiation increases the performance and productivity of the solar chimney. The analytical results of this paper were compared with previous literature studies and showed a great convergence between them.  

scholarly journals PENGARUH BUKAAN SAMPING (CLERESTORY) TERHADAP KUALITAS KENYAMANAN TERMAL PADA FOOD CARNIVAL, MALL AEON BSD

Vitruvian ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 47
Author(s):  
Tathia Edra Swasti
Keyword(s):  
Wind Speed ◽  
Thermal Comfort ◽  
Air Temperature ◽  
Effective Temperature ◽  
Air Humidity ◽  
Air Velocity ◽  
Predicted Mean Vote ◽  
Air Speed ◽  
The Right

ABSTRAK Mall saat ini marak menggunakan clerestory sebagai salah satu upaya untuk penerangan alami pada siang hari. Namun, cahaya matahari pada sore hari (barat) akan menghasilkan cahaya matahari yang lebih panas dan silau dibandingkan cahaya matahari pada pagi hari (timur). Oleh karena itu, dengan pemakaian clerestory yang cukup besar pada bangunan, masalah panas tentu tak dapat dihindari. Begitu pula dengan glare yang berasal dari pantulan sinar matahari. Salah satu Mall yang menggunakan clerestory adalah Mall AEON BSD. Pengukuran suhu udara, temperatur efektif, kelembaban udara, kecepatan angin, PMV (Predicted Mean Vote) dan PPD (Predicted Percentage of Dissatisfied) dilaksanakan pada 4 waktu dengan 5 lokasi titik ukur yang memiliki kondisi berbeda untuk membuktikan bahwa clerestory dapat mempengaruhi kenyamanan termal. Disimpulkan bahwa titik 2 yaitu titik yang berdekatan dengan clerestory sisi kanan (ukurannya lebih kecil daripada clerestory sisi kiri) memiliki temperatur efektif dan kelembaban udara yang lebih rendah dari titik lain, dan kecepatan udara (dipengaruhi oleh hembusan AC) lebih tinggi dari titik lain. Responden merasa nyaman saat berada di titik tersebut.Titik paling nyaman menurut responden adalah titik 2 dengan TE rata-rata berkisar 27,4˚C, kelembaban udara rata-rata berkisar 52,2%, kecepatan udara rata-rata berkisar 0,15 m/s, PMV berkisar 0,5 dan PPD berkisar 12,7%. Dengan begitu semakin kecil ukuran skylight terbukti mempengaruhi kenyamanan termal dan membuat kenyamanan termal dapat tercapai. Kata Kunci: Mall, Clerestory, PMV, PPD, Kenyamanan Termal ABSTRACT Nowadays mall is decorated with clerestory as an effort to lighten naturally during the day. However, sunlight in the afternoon (west) will produce more sunlight and glare than sunlight in the morning (east). Therefore, with the use of a fairly large clerestory in buildings, the problem of heat certainly can not be avoided. Similarly, glare that comes from the reflection of sunlight. One of the malls that use clerestory is BSD AEON Mall. Measurement of air temperature, effective temperature, air humidity, wind speed, PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied) carried out at 4 times within 5 measuring spots that have different conditions, proving that clerestory can affect thermal comfort. It was concluded that point 2, which is the point adjacent to the right side clerestory (smaller in size than the left side clerestory) has an effective temperature and lower air humidity than other points, and air velocity (affected by blowing AC) is higher than other points. Respondents felt comfortable when they were at that point. The most comfortable point according to respondents was point 2 with TE averaging around 27.4˚C, air humidity averaged 52.2%, the average air speed ranged from 0.15 m / s, PMV ranges from 0.5 and PPD ranges from 12.7%. Thus, the smaller size of the clerestory is affecting thermal comfort and thermal comfort can be achieved. Keywords: Mall, Clerestory, PMV, PPD, Thermal Comfort

scholarly journals Modeling the surface stored thermal energy in asphalt concrete pavements

2016 ◽  
Vol 20 (suppl. 2) ◽  
pp. 603-610
Author(s):  
Bojan Matic ◽  
Hasan Salem ◽  
Vlastimir Radonjanin ◽  
Nebojsa Radovic ◽  
Sinisa Sremac
Keyword(s):  
Neural Networks ◽  
Regression Analysis ◽  
Wind Speed ◽  
Solar Radiation ◽  
Air Temperature ◽  
Asphalt Concrete ◽  
Concrete Pavements ◽  
New Models ◽  
Pavement Temperature ◽  
The Republic

Regression analysis is used to develop models for minimal daily pavement surface temperature, using minimal daily air temperature, day of the year, wind speed and solar radiation as predictors, based on data from Awbari, Lybia,. Results were compared with existing SHRP and LTPP models. This paper also presents the models to predict surface pavement temperature depending on the days of the year using neural networks. Four annual periods are defined and new models are formulated for each period. Models using neural networks are formed on the basis of data gathered on the territory of the Republic of Serbia and are valid for that territory.

scholarly journals Investigation on the Temperature Distribution of Asphalt Overlay on the Existing Cement Concrete Pavement in Hot-Humid Climate in Southern China

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zuzhong Li ◽  
Yayun Zhang ◽  
Chunguang Fa ◽  
Xiaoming Zou ◽  
Haiwei Xie ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Prediction Model ◽  
Air Temperature ◽  
Concrete Pavement ◽  
Humid Climate ◽  
Temperature Prediction ◽  
Asphalt Overlay ◽  
Hot Humid Climate

Temperature is known to be one of the most important factors affecting the design and performance of asphalt concrete pavement. The distresses of asphalt overlay are closely related to its temperature, particularly in Guangxi, a hot-humid-climate region in China. This research is to analyze the impact of meteorological factors on temperature at 2 cm depth in asphalt overlay by ReliefF algorithm and also obtain the temperature prediction model using MATLAB. Two test sites were installed to monitor the temperatures at different pavement depths from 2014 to 2016; meanwhile, the meteorological data (including air temperature, solar radiation, wind speed, and relative humidity) were collected from the two meteorological stations. It has been found that the temperature at 2 cm depth experiences greater temperature variation, and the maximum and minimum temperatures of asphalt overlay, respectively, occur at 2 cm depth and on the surface. Besides, the results of ReliefF algorithm have also shown that the temperature at 2 cm depth is affected significantly by solar radiation, air temperature, wind speed, and the relative humidity. Based on these analyses, the prediction model of maximum temperature at 2 cm depth is developed using statistical regression. Moreover, the data collected in 2017 are used to validate the accuracy of the model. Compared with the existing models, the developed model was confirmed to be more effective for temperature prediction in hot-humid region. In addition, the analysis of rutting depth and overlay deformation for the two test sections with different materials is done, and the results have shown that reasonable structure and materials of asphalt overlay are vital to promote the high-temperature antideforming capability of pavement.

Performance of a Solar Chimney With a Modified Collector Geometry: A Case Study From Erbil to the North of Iraq

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Dara Khalid Khidhir ◽  
Soorkeu A. Atrooshi
Keyword(s):  
Solar Radiation ◽  
Ambient Temperature ◽  
Temperature Difference ◽  
Mechanical Energy ◽  
Maximum Temperature ◽  
Geometrical Shape ◽  
Solar Chimney ◽  
Air Velocity ◽  
Temperature Loss ◽  
Solar Intensity

Abstract The principle of solar chimney power plant (SCPP) is based on harvesting the thermal spectrum of solar radiation and converting it to mechanical energy by the means of a collector, a wind turbine, and a chimney. In this work, a number of experiments were performed on a modified model made up of one-third of the circular collector area. Field data from selected clear, sunny days were recorded and studied. The analysis focused on time-temperature relations for ambient, near chimney entry point and the collector periphery, in addition to hourly solar radiation intensity and air velocity inside the chimney. The results show that for this geometry arrangement, the maximum temperature of the air entering the chimney is achieved before the ambient temperature reaches its peak value. Air velocity inside the chimney depends on the intensity of solar radiation and the temperature difference between the air temperature entering the chimney and the ambient temperature. Solar intensity directly affects the temperature of air beneath the collector, and a part of this energy is stored in the ground. Later, when the solar radiation is impaired, the stored energy can be utilized. Air velocity of 2.1 m/s is obtained after the solar noon, when the solar intensity is 737 W/m2 and the maximum temperature difference is 11.2 °C. Due to the unique geometrical shape of the rig, a minor temperature loss of up to 1.3 °C occurs for the air near the center of the chimney.

Solar Chimney Cycle Analysis With System Loss and Solar Collector Performance

2000 ◽  
Vol 122 (3) ◽  
pp. 133-137 ◽  
Author(s):  
Anthony J. Gannon ◽  
Theodor W. von Backstro¨m
Keyword(s):  
Experimental Data ◽  
Simple Model ◽  
Power Plant ◽  
Kinetic Energy ◽  
Solar Collector ◽  
Large Scale ◽  
Small Scale ◽  
Energy Losses ◽  
Solar Chimney ◽  
Solar Chimney Power Plant

An ideal air standard cycle analysis of the solar chimney power plant gives the limiting performance, ideal efficiencies and relationships between main variables. The present paper includes chimney friction, system, turbine and exit kinetic energy losses in the analysis. A simple model of the solar collector is used to include the coupling of the mass flow and temperature rise in the solar collector. The method is used to predict the performance and operating range of a large-scale plant. The solar chimney model is verified by comparing the simulation of a small-scale plant with experimental data. [S0199-6231(00)00503-7]

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.

An Unsteady Model for Natural Ventilation with Solar Chimney

2011 ◽  
Vol 354-355 ◽  
pp. 286-289 ◽  
Author(s):  
Zhong Bao Liu ◽  
Ya Xin Su
Keyword(s):  
Solar Radiation ◽  
Mass Flow Rate ◽  
Air Temperature ◽  
Mass Flow ◽  
Flow Rate ◽  
Natural Ventilation ◽  
Thermal Inertia ◽  
Solar Chimney ◽  
Air Mass ◽  
Peak Value

A one dimensional unsteady mathematical model for predicting the air mass flow rate in a solar chimney has been proposed. The thermal resistance and thermal inertia of both the glass cover and heat absorbing wall were considered in the present model. Crank-Nicolson finite difference numerical method was used to solve the differential equations. The variation of the air temperature in the solar chimney was solved by integrating the controlling equation for the air along the chimney height. Results show the absorber wall reaches its peak temperature 2 hours later with respect to the maximum ambient temperature. The air temperature in the channel varies with the solar radiation in a day and researches its peak value at about 2:00pm. The air mass flow rate increases remarkably with the increase of the channel depth when the solar radiation is higher from 11:00 am to 3:00 pm. The maximum of air mass flow rate occurs at around 2:00pm

scholarly journals Ocena bioklimatycznych warunków rekreacji i turystyki w strefie polskiego Wybrzeża Bałtyku na podstawie wskaźnika UTCI = Assessment of bioclimatic conditions for recreation and tourism in the Polish Baltic coastal zone using the UTCI index

2019 ◽  
Vol 91 (2) ◽  
pp. 113-126 ◽  
Author(s):  
Czesław Koźmiński ◽  
Bożena Michalska
Keyword(s):  
Heat Stress ◽  
Wind Speed ◽  
Solar Radiation ◽  
Cold Stress ◽  
Air Temperature ◽  
Human Organism ◽  
Heat Loading ◽  
Extreme Cold ◽  
Bioclimatic Conditions ◽  
Recreation And Tourism

The quality of a given bioclimate is much affected by the atmospheric environment (taken to include solar radiation, air temperature and humidity, atmospheric pressure, wind speed and levels of atmospheric pollution), as well as by geographical factors relating to topography and cover, the drainage system and land use (Owczarek 2009, Czarnecka, Nidzgorska-Lencewicz 2010, Koźmiński, Michalska 2011, Owczarek 2012). Tourists staying in a coastal area must contend with considerable variability of weather from one day to another, or even hour by hour, in the cold half-year in particular. Changes of weather have a profound effect on the human organism, inter alia giving rise to migraines, sleep disturbances and hypersensitivity. The work described here sought to assess temporal (inter alia seasonal) and spatial variability to heat loading of the human organism characterising the Polish Baltic coastal zone, as well as the temperature of water by beaches. It was to achieve this kind of assessments of bioclimate and its impact on the human organism that the index known as the UTCI (Universal Thermal Climate Index) was devised, taking in air temperature, wind speed, air humidity and absorbed solar radiation (expressed as mean radiant temperature) (Błażejczyk & Kunert, 2011). This index represents objective changes in physiological parameters of the human organism occurring thanks to differing environmental conditions as determined in relation to a 10-point scale for heat loading of the human organism (°C) that translate into descriptive terms ranging from extreme heat stress to extreme cold stress. UTCI values referred to here were calculated using BioKlima 2.6 software - http://www.igipz.pan.pl/Bioklima-zgik.html. Six zones for the heat loading of the human organism found to be present along the Polish coast during the four seasons of the year were designated by summing the frequency of occurrence of days with a particularly stimulating effect, be this severe or very severe heat stress or severe, very severe or extreme cold stress. The UTCI-based analysis sustained conclusions as follows: - The Polish Baltic coast is found to be characterised by marked day-to-day variability in the heat loading of the human organism, particularly in the November-late May period, with the result being a significant “nuisance” represented for tourists. - Along the western part of the coast and in the area of the Bay of Puck, conditions thermoneutral for the human organism were found to dominate (accounting for more than 60% of the days in a month) over the whole period from May through to mid-October. In the case of the northern part of the coast from Darłowo to Łeba the same was found to be true of the period extending from June through to the middle ten-day period of September, creating conditions favourable for outdoor recreation. - The duration of the bathing season with mean monthly water temperatures ≥18°C is of approximately 45 days along the coast from Darłowo to Łeba, 46-50 days in the central part of the coast, 46-60 days in the area of the Bay of Gdańsk and 61-70 in the area of the Bay of Pomerania. In most years under analysis, there was no identification of a bathing season with mean monthly water temperature ≥18°C in the Kołobrzeg and Władysławowo areas. - The bioclimatic conditions most favourable for recreation and tourism were identified for the area of the Bay of Pomerania, followed by the Bay of Gdańsk. Less-favourable conditions characterise the central part of the coast, while the least favourable circumstances extend through the northern area from Darłowo to Łeba, in which the bioclimate’s stimulatory effect is strongest.- The high spatial variability characterising heat loading of the human organism that it proved possible to identify for the Polish coast offers the possibility of particular regions and seasons being selected for recreation, in relation to tourists’ health status and specific requirements.

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