scholarly journals Performance Evaluation of Solar Air Collector by Chimney Effect for Drying Applications

2021 ◽  
Vol 24 (4) ◽  
pp. 159-165
Author(s):  
Gedion Habtay Gebremicheal ◽  
Janos Buzas ◽  
István Farkas
Keyword(s):  
Thermal Efficiency ◽  
Collector System ◽  
Solar Radiation Intensity ◽  
Solar Air Collector ◽  
Collector Efficiency ◽  
Extended Surfaces ◽  
Main Components ◽  
The Cost ◽  
Cost Of Construction ◽  
Chimney Effect

Abstract Solar air collector is one of the main components of a solar dryer unit, which supplies the conditioned air for processing the perishable edible items. Various techniques have been employed to improve the thermal efficiency of the collector system, such as extended surfaces, packed beds, artificial roughness, etc., however, the cost of construction is higher. Therefore, this study was focussed on the collector efficiency enhancement using a chimney without applying the aforementioned. A single-pass solar air collector coupled with drying chamber and chimney was utilized for the experiments. The experiments were conducted in September. The average values of the solar radiation intensity, ambient temperature, temperatures inside the dryer, collector efficiency were graphically presented. The experimental data reported the maximum values of the outlet temperatures for the solar air collector with and without a chimney to be 52.8 °C and 57 °C, respectively. The collector thermal efficiency with and without the chimney was found to vary from 29.6% to 64.8% and from 26.9% to 44.8%, respectively. Furthermore, it was noticed that, with the chimney, the temperature inside the dryer showed uniform tendency.

A Numerical Study on Integral Solar Air Collector

2013 ◽  
Vol 860-863 ◽  
pp. 146-150
Author(s):  
Fu Sheng Dong ◽  
Ming Fu Hu ◽  
Xiao Chun Huang
Keyword(s):  
Mathematical Model ◽  
Solar Radiation ◽  
Thermal Efficiency ◽  
Radiation Intensity ◽  
Numerical Study ◽  
One Dimension ◽  
Inlet Temperature ◽  
Solar Radiation Intensity ◽  
Solar Air Collector ◽  
Matlab Programming

A mathematical modeling method was devoted to study the thermal performance of integral solar air collector. A mathematical model of heat transfer was set up based on one-dimension assumptions at first, and then numerical solution was brought out by using finite-difference method under one-dimension steady heat exchange. Through the MATLAB programming, the approximate solutions for the local air temperature and thermal efficiency were obtained at the quasi-steady state. After calculation, the influence of air inlet velocity, inlet temperature, solar radiation intensity and height of flow channel on the performance of collector was analyzed. It is discovered that the mathematical model is reasonable, the thermal efficiency decreases with temperature of inlet air increasing and increases with air velocity increasing, on which the solar radiation intensity have little influence. Depth of the channel and optimum flow both have a best value.

scholarly journals Energy-based performance analysis of a double pass solar air collector integrated to triangular shaped fins

2021 ◽  
Author(s):  
Maytham H. Machi ◽  
Maytham A. Al-Neama ◽  
J. Buzás ◽  
I. Farkas
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Outlet Temperature ◽  
Double Pass ◽  
Solar Air Collector ◽  
Collector Efficiency ◽  
Useful Heat ◽  
Air Channels

AbstractIn this paper, the performance of a double pass solar air collector with triangular integrated fins was investigated experimentally at Hungarian University of Agriculture and Life Sciences in Gödöllő, Hungary. The focus of this research is on energy-based performance evaluation. The thermal efficiency of the collector has been compared by testing two collectors that had the same design, with and without fins. The effect of the collector's air mass flow rate on thermal performance was investigated under various environmental situations. The results revealed that the temperature difference is always higher through the finned collector and the higher variation temperature between the inlet and outlet temperature leads to higher useful heat. The daily thermal efficiency of the finned collector was 56.57%, 59.41%, and 61.42%, while for the un-finned collector was 51.04%, 53.28%, and 57.08% for the mass flow rate 0.0081, 0.0101, and 0.0121 kg/s. The finned double pass solar air collector improved the thermal efficiency by 4.3–6.1% over the un-finned one. The efficiency of the finned collector is always higher than the un-finned one regardless of the mass flow rate. The presence of the fins to the top air channels significantly increases collector efficiency, owing to the increased absorbing surface area, which is responsible for increasing the internal thermal convective exchanges. Moreover, it creates a turbulence airflow, meaning that the air will be in good contact with the absorber plate and penetrate all regions, reducing the dead zones contributing to increased heat transfer.

Exergoeconomic analysis of renewable multi-generation system

2020 ◽  
pp. 99-111
Author(s):  
Vontas Alfenny Nahan ◽  
Audrius Bagdanavicius ◽  
Andrew McMullan
Keyword(s):  
Capital Investment ◽  
Combined Cycle ◽  
Asian Countries ◽  
Generation System ◽  
Integrated Gasification Combined Cycle ◽  
Heating And Cooling ◽  
Integrated Gasification ◽  
Exergoeconomic Analysis ◽  
Main Components ◽  
The Cost

In this study a new multi-generation system which generates power (electricity), thermal energy (heating and cooling) and ash for agricultural needs has been developed and analysed. The system consists of a Biomass Integrated Gasification Combined Cycle (BIGCC) and an absorption chiller system. The system generates about 3.4 MW electricity, 4.9 MW of heat, 88 kW of cooling and 90 kg/h of ash. The multi-generation system has been modelled using Cycle Tempo and EES. Energy, exergy and exergoeconomic analysis of this system had been conducted and exergy costs have been calculated. The exergoeconomic study shows that gasifier, combustor, and Heat Recovery Steam Generator are the main components where the total cost rates are the highest. Exergoeconomic variables such as relative cost difference (r) and exergoeconomic factor (f) have also been calculated. Exergoeconomic factor of evaporator, combustor and condenser are 1.3%, 0.7% and 0.9%, respectively, which is considered very low, indicates that the capital cost rates are much lower than the exergy destruction cost rates. It implies that the improvement of these components could be achieved by increasing the capital investment. The exergy cost of electricity produced in the gas turbine and steam turbine is 0.1050 £/kWh and 0.1627 £/kWh, respectively. The cost of ash is 0.0031 £/kg. In some Asian countries, such as Indonesia, ash could be used as fertilizer for agriculture. Heat exergy cost is 0.0619 £/kWh for gasifier and 0.3972 £/kWh for condenser in the BIGCC system. In the AC system, the exergy cost of the heat in the condenser and absorber is about 0.2956 £/kWh and 0.5636 £/kWh, respectively. The exergy cost of cooling in the AC system is 0.4706 £/kWh. This study shows that exergoeconomic analysis is powerful tool for assessing the costs of products.

ABOUT NECESSITY OF MATHEMATICAL MODELING OF THE BUSINESS PROCESS OF COST ESTIMATE CALCULATIONS IN THE CONSTRUCTION OF OIL AND GAS FACILITIES

2017 ◽  
pp. 139-145
Author(s):  
R. I. Hamidullin ◽  
L. B. Senkevich
Keyword(s):  
Mathematical Modeling ◽  
Quality Assessment ◽  
Business Process ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Gas Industry ◽  
Construction Organizations ◽  
The Cost ◽  
Cost Of Construction

A study of the quality of the development of estimate documentation on the cost of construction at all stages of the implementation of large projects in the oil and gas industry is conducted. The main problems that arise in construction organizations are indicated. The analysis of the choice of the perfect methodology of mathematical modeling of the investigated business process for improving the activity of budget calculations, conducting quality assessment of estimates and criteria for automation of design estimates is performed.

This Is an Abridged Account of Delhi Which Is an Old City and One of the Chosen Ones amongst the Cities

2018 ◽  
Author(s):  
Mirza Sangin Beg
Keyword(s):  
Popular Culture ◽  
East India Company ◽  
Ordinary People ◽  
Work Spaces ◽  
History Of ◽  
English East India Company ◽  
Local Traditions ◽  
The Cost ◽  
The City ◽  
Cost Of Construction

The second part of the translation has three segments. The first is dedicated to the history of Delhi from the time of the Mahabharat to the periods of Anangpal Tomar to the Mughal Emperor Humayun as also Sher Shah, the Afghan ruler. In the second and third segments Mirza Sangin Beg adroitly navigates between twin centres of power in the city. He writes about Qila Mubarak, or the Red Fort, and gives an account of the several buildings inside it and the cost of construction of the same. He ambles into the precincts and mentions the buildings constructed by Shahjahan and other rulers, associating them with some specific inmates of the fort and the functions performed within them. When the author takes a walk in the city of Shahjahanabad, he writes of numerous residents, habitations of rich, poor, and ordinary people, their mansions and localities, general and specialized bazars, the in different skills practised areas, places of worship and revelry, processions exemplifying popular culture and local traditions, and institutions that had a resonance in other cultures. The Berlin manuscript gives generous details of the officials of the English East India Company, both native and foreign, their professions, and work spaces. Mirza Sangin Beg addresses the issue of qaum most unselfconsciously and amorphously.

Utilization of Dacite as Alternative Aggregate in Asphalt Mixture

2012 ◽  
Vol 509 ◽  
pp. 209-214
Author(s):  
Shao Peng Wu ◽  
Pan Pan ◽  
Ming Yu Chen
Keyword(s):  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Major Objective ◽  
Widespread Application ◽  
Bending Tests ◽  
Three Point Bending ◽  
Large Numbers ◽  
Asphalt Content ◽  
The Cost ◽  
Cost Of Construction

With the widespread application of asphalt mixture, current demand from transportation managers for construction and maintenance of their pavement network consumes large numbers of aggregates. If agencies excessively favor to some certain kinds of excellent aggregates, the cost of construction could be considerably expensive. The major objective of this study is to determine the feasibility of utilizing dacite in asphalt mixtures. By means of Marshall, freeze-thaw, rutting and three-point bending tests, the performances of dacite and basalt asphalt mixture are compared. The results of the testing illustrate that dacite asphalt mixture is more susceptible to gradation and asphalt content than basalt asphalt mixture. Meanwhile it is showed that the performances of dacite asphalt mixture can be improved greatly with the involvement of additives including active mineral powder and cement. Furthermore, it is validated that dacite can be used as alternative aggregate in asphalt mixture.

Models for New Corrugated and Porous Solar Air Collectors under Transient Operation

2017 ◽  
Vol 42 (1) ◽  
Author(s):  
Qahtan Adnan Abed ◽  
Viorel Badescu ◽  
Adrian Ciocanea ◽  
Iuliana Soriga ◽  
Dorin Bureţea
Keyword(s):  
Climatic Conditions ◽  
Meteorological Conditions ◽  
Bias Error ◽  
First Order ◽  
Solar Air Collector ◽  
Section Surface ◽  
South Eastern Europe ◽  
Main Components ◽  
Theoretical Results ◽  
Good Agreement

AbstractMathematical models have been developed to evaluate the dynamic behavior of two solar air collectors: the first one is equipped with a V-porous absorber and the second one with a U-corrugated absorber. The collectors have the same geometry, cross-section surface area and are built from the same materials, the only difference between them being the absorbers. V-corrugated absorbers have been treated in literature but the V-porous absorbers modeled here have not been very often considered. The models are based on first-order differential equations which describe the heat exchange between the main components of the two types of solar air heaters. Both collectors were exposed to the sun in the same meteorological conditions, at identical tilt angle and they operated at the same air mass flow rate. The tests were carried out in the climatic conditions of Bucharest (Romania, South Eastern Europe). There is good agreement between the theoretical results and experiments. The average bias error was about 7.75 % and 10.55 % for the solar air collector with “V”-porous absorber and with “U”-corrugated absorber, respectively. The collector based on V-porous absorber has higher efficiency than the collector with U-corrugated absorber around the noon of clear days. Around sunrise and sunset, the collector with U-corrugated absorber is more effective.

scholarly journals Problem Faced by Precast Industry to Implement in Residential Construction

2020 ◽  
Vol 9 (5) ◽  
pp. 2394-2396
Keyword(s):  
Residential Construction ◽  
Joint Stability ◽  
Standard Size ◽  
Research Survey ◽  
Technical Issues ◽  
Storage Area ◽  
Standard Rate ◽  
The Cost ◽  
Cost Of Construction

The Precast industry is booming industry now a day, but then also the implementation ratio of precast member in residential construction work is not up to the mark. As we all know that precast having numerous advantages over the cast in situ construction method, for example it saves the total time of construction which indirectly reduces the cost of construction but still we are lagging behind in implementation of precast in it. In this research we have listed out some problem which can be cause of less implementation of precast in residential construction buildings. As discussed in paper, there are so many factors are affected on Implementation of Precast in Residential Construction Sector For example: Technical Issues and General Issues. In Technical Issues Joint stability problem during Erection, Standard size of precast element, Leakage Issues, Design change related problem, Requirement of Standard Rate per Panel, End user Profit, Additional Taxes, General Issues are: Transportation of Precast Element, Loading and Unloading problems, Transportation to sight, Storage Area, Skilled Labour Research has done and data is collected through Questionery survey, Field survey, and research survey.

scholarly journals Effect of a dual tire pressure on the design parameters of thick asphalt pavements using finite element freeware

DYNA ◽  
2016 ◽  
Vol 83 (196) ◽  
pp. 194-203
Author(s):  
Myriam Rocío Pallares Muñoz ◽  
Julián Andrés Pulecio-Díaz
Keyword(s):  
Finite Element ◽  
Analytical Methods ◽  
Asphalt Pavement ◽  
Field Tests ◽  
Asphalt Pavements ◽  
Design Parameters ◽  
Future Research ◽  
Tire Pressure ◽  
The Cost ◽  
Cost Of Construction

<p>The effect of a dual tire pressure on the design parameters of thick asphalt pavements using finite element freeware EverStressFE©1.0 is evaluated. This is trying to represent more adjusted the footprint shape and intensity of stress generated by the tires of vehicles. To validate the elastic multilayer EverStress©5.0 software was used. The results of the deformations can be concluded that the asphalt pavement designs made with analytical methods may be slightly oversized and consequently increase the cost of construction of pavements. This study marks a route to analyze the sensitivity of various factors that may affect the design of asphalt pavements. Future research is expected to integrate dynamic conditions by introducing results of field tests to full scale.</p>

Heat Utilization of Solar Energy in Burley Tobacco Modulation

2013 ◽  
Vol 773 ◽  
pp. 101-107
Author(s):  
Chun Lei Yang ◽  
Xiao Yan Yuan ◽  
Jun Yu ◽  
Jin Peng Yang ◽  
Shu Yang ◽  
...  
Keyword(s):  
Curing Process ◽  
Solar Collectors ◽  
Average Income ◽  
Average Temperature ◽  
Burley Tobacco ◽  
Curing Period ◽  
Utility System ◽  
Collector Efficiency ◽  
The Cost

In Hubei Province in China, About 15%-40% yield of Burley tobacco losses caused by mildew during air-curing period for High humidity and low temperature. In this paper, active solar utility system was first applied to condition temperature and humidity in the air-curing process. Forced convection solar collectors, natural convection solar collectors and air circulates system were applied in the solar Burley barns. The results showed that: The cost of the system was about 1226 ¥ per drying barn, but it could quickly increase the temperature and reduce the relative humidity of the barn, and the quality and yield were raised. The collector efficiency was about 18.8-24.9%. The average temperature of barn could be improved to 3-4 °Ceven in rainy days. The quality of upper and middle tobacco was enhanced by 11% to 13%; Yields increased by 18% to 23%; The income per acre added 371-392¥; the average income of tobacco increased from 10.49 to 10.87 ¥ per kilograms .

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