scholarly journals Performance Characteristics of a Cooking Stove Improved with Sawdust as an Insulation Material

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jasper Okino ◽  
Allan John Komakech ◽  
Joshua Wanyama ◽  
Herbert Ssegane ◽  
Elly Olomo ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Thermal Efficiency ◽  
Energy Demand ◽  
Eucalyptus Grandis ◽  
Thick Layer ◽  
Outer Wall ◽  
Insulation Material ◽  
Pinus Caribaea ◽  
Water Boiling Test ◽  
Exponential Population Growth

In developing countries, energy demand from biomass has increased due to exponential population growth. This has translated into voluminous quantities of wood being used. The situation is exacerbated by the popular use of inefficient stoves with low thermal insulation, hence contributing to deforestation. In this study, the performance of a cooking stove improved with sawdust as an insulation material was assessed. An insulated fire stove prototype of 26 cm saucepan diameter was designed, constructed, and cast with sawdust and clay in a ratio of 1 : 1 (as the first layer) and sawdust alone as the second layer. The developed stove was tested using a water boiling test to establish its operating performance. The thermal efficiency of the stove was assessed using indigenous wood fuels used in rural Uganda (Senna spectabilis, Pinus caribaea, and Eucalyptus grandis). Computational fluid dynamics was used to simulate the temperature and velocity fields within the combustion chamber and for generating temperature contours of the stove. Obtained results indicated that S. spectabilis had the highest thermal efficiency of 35.5 ± 2.5%, followed by E. grandis (25.7 ± 1.7%) and lastly P. caribaea (19.0 ± 1.2%) in the cold start phase when compared with traditional stoves. The stove remained cold as hot air was restricted to the combustion chamber with decreasing temperature contours toward the outer wall up to the ambient temperature. The velocity flow remained constant as the chamber was colored green throughout due to the shielding of the stove with sawdust as insulation. The heat flux generated indicated that a thick layer of 6 cm or more could ensure good insulation, and this could be further reduced by introducing more sawdust. The designed stove has the potential to reduce biomass consumption and emissions when compared to traditional cookstoves. The inclusion of a chimney draught in the fire stove prototype could reduce smoke and increase thermal efficiency. Further studies should focus on minimizing the thickness of the clay-sawdust (first) layer and increasing the thickness of the sawdust layer to reduce the weight of the fire stove.

scholarly journals Urban Geometry Optimization to Mitigate Climate Change: Towards Energy-Efficient Buildings

2020 ◽  
Vol 13 (1) ◽  
pp. 27
Author(s):  
Hatem Mahmoud ◽  
Ayman Ragab
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Thermal Efficiency ◽  
Energy Demand ◽  
Building Blocks ◽  
Climate Projections ◽  
Climate Change Scenarios ◽  
Urban Geometry ◽  
Outdoor Spaces ◽  
The Impact

The density of building blocks and insufficient greenery in cities tend to contribute dramatically not only to increased heat stress in the built environment but also to higher energy demand for cooling. Urban planners should, therefore, be conscious of their responsibility to reduce energy usage of buildings along with improving outdoor thermal efficiency. This study examines the impact of numerous proposed urban geometry cases on the thermal efficiency of outer spaces as well as the energy consumption of adjacent buildings under various climate change scenarios as representative concentration pathways (RCP) 4.5 and 8.5 climate projections for New Aswan city in 2035. The investigation was performed at one of the most underutilized outdoor spaces on the new campus of Aswan University in New Aswan city. The potential reduction of heat stress was investigated so as to improve the thermal comfort of the investigated outdoor spaces, as well as energy savings based on the proposed strategies. Accordingly, the most appropriate scenario to be adopted to cope with the inevitable climate change was identified. The proposed scenarios were divided into four categories of parameters. In the first category, shelters partially (25–50% and 75%) covering the streets were used. The second category proposed dividing the space parallel or perpendicular to the existing buildings. The third category was a hybrid scenario of the first and second categories. In the fourth category, a green cover of grass was added. A coupling evaluation was applied utilizing ENVI-met v4.2 and Design-Builder v4.5 to measure and improve the thermal efficiency of the outdoor space and reduce the cooling energy. The results demonstrated that it is better to cover outdoor spaces with 50% of the overall area than transform outdoor spaces into canyons.

A Comparison Between ORC and Supercritical CO2 Bottoming Cycles For Energy Recovery From Industrial Gas Turbines Exhaust Gas

2021 ◽  
Author(s):  
M. A. Ancona ◽  
M. Bianchi ◽  
L. Branchini ◽  
A. De Pascale ◽  
F. Melino ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Supercritical Co2 ◽  
Energy Demand ◽  
Oil And Gas ◽  
Gas Production ◽  
Medium Size ◽  
Oil And Gas Production ◽  
Industrial Gas Turbines

Abstract Gas turbines are often employed in the industrial field, especially for remote generation, typically required by oil and gas production and transport facilities. The huge amount of discharged heat could be profitably recovered in bottoming cycles, producing electric power to help satisfying the onerous on-site energy demand. The present work aims at systematically evaluating thermodynamic performance of ORC and supercritical CO2 energy systems as bottomer cycles of different small/medium size industrial gas turbine models, with different power rating. The Thermoflex software, providing the GT PRO gas turbine library, has been used to model the machines performance. ORC and CO2 systems specifics have been chosen in line with industrial products, experience and technological limits. In the case of pure electric production, the results highlight that the ORC configuration shows the highest plant net electric efficiency. The average increment in the overall net electric efficiency is promising for both the configurations (7 and 11 percentage points, respectively if considering supercritical CO2 or ORC as bottoming solution). Concerning the cogenerative performance, the CO2 system exhibits at the same time higher electric efficiency and thermal efficiency, if compared to ORC system, being equal the installed topper gas turbine model. The ORC scarce performance is due to the high condensing pressure, imposed by the temperature required by the thermal user. CO2 configuration presents instead very good cogenerative performance with thermal efficiency comprehended between 35 % and 46 % and the PES value range between 10 % and 22 %. Finally, analyzing the relationship between capital cost and components size, it is estimated that the ORC configuration could introduce an economical saving with respect to the CO2 configuration.

scholarly journals Fertilização de mudas de espécies arbóreas nativas e exóticas

2003 ◽  
Vol 27 (2) ◽  
pp. 129-137 ◽  
Author(s):  
Sebastião Pires de Moraes Neto ◽  
José Leonardo de Moraes Gonçalves ◽  
José Carlos Arthur Jr. ◽  
Fabiane Ducatti ◽  
José Hamilton Aguirre Jr.
Keyword(s):  
Eucalyptus Grandis ◽  
Pinus Caribaea ◽  
Guazuma Ulmifolia

Doses crescentes de fertilizante de liberação controlada (FLC) foram comparadas com fertilização convencional e tratamento sem fertilização. Estes tratamentos foram testados em mudas das pioneiras Guazuma ulmifolia (mutambo), Eucalyptus grandis e Pinus caribaea var. caribaea, da secundária inicial Peltophorum dubium (canafístula) e da clímax Calycophyllum spruceanum (mulateiro), as quais cresceram em casa de vegetação. As mudas foram cultivadas em tubetes de 50 cm³ de capacidade, tendo como substrato uma mistura contendo 50% de húmus de minhoca, 30% de casca de eucalipto decomposta e 20% de casca de arroz carbonizada, em base volumétrica. Aos 125 dias após a semeadura, as mudas de G. ulmifolia, E. grandis e P. dubium submetidas à fertilização convencional apresentaram maior crescimento em altura e biomassa seca da parte aérea comparados aos dos tratamentos que receberam FLC. Contudo, para estas espécies, a biomassa seca da raiz das mudas submetidas ao tratamento convencional foram semelhantes à das mudas produzidas com as duas maiores doses de FLC (4,28 e 6, 42 kg/m³ de substrato), e a razão entre raiz e parte aérea foi maior para a dose de 6,42 kg/m³ (FLC), comparada à do tratamento convencional para as duas primeiras espécies. O Calycophyllum spruceanum e o Pinus caribaea var. caribaea tiveram pequeno desenvolvimento em todos os tratamentos, aos 125 dias.

scholarly journals Performance Test of a Household Rocket Stoves Fired with Coconut Frond, Coconut Shell and Bamboo

2021 ◽  
Vol 8 (1) ◽  
pp. 59-64
Author(s):  
Almuzakkir . ◽  
Muhammad . ◽  
Adi Setiawan
Keyword(s):  
Thermal Efficiency ◽  
Fossil Fuels ◽  
Performance Test ◽  
Performance Testing ◽  
Biomass Energy ◽  
Test Method ◽  
Fuel Oil ◽  
Coconut Shell ◽  
Water Boiling Test ◽  
A Value

Fuel is something that is very important in everyday life. Almost every human being needs fuel to meet their needs and support their activities, for example cooking in household needs. Currently, fossil fuels or fuel oil (BBM) are still widely used to meet demand, however, it should be noted that fossil fuels or fuel oil (BBM) are non-renewable natural resources. The biomass rocket stove is one of the modern stove innovations that uses biomass energy as the main energy source. Rocket stoves are designed to increase fuel efficiency with thermal efficiency, a combination of the increased combustion efficiency and heat transfer associated with burning briquette fuel. The purpose of this research is to design and manufacture rocket stove fired with coconut and bamboo biomass for household needs as well as developing methods and equipment for performance testing of rocket stoves. In this study, several steps were carried out, including designing a rocket furnace, selecting biomass fuel and testing the performance of a rocket furnace. From the design of the biomass stove, it is noteworthy that the design with two holes makes the combustion air easily enters and makes combustion in the furnace more perfect and efficient. Water boiling test using three types of solid fuels with the cold start condition suggested that the highest thermal efficiency was coconut fronds with a value of 38% and the lowest thermal efficiency was found from coconut shell combustion, i.e. 22%. During hot start test, the highest thermal efficiency was obtained from coconut fronds firing with a value of 41%. Moreover, with simmer water boiling test method, firing the rocket stove with coconut fronds showed the highest thermal efficiency with a value of 37%. Keywords: Rocket Stoves, Coconut Fronds and Shells, Bamboo, Thermal Efficiency, .Water Boiling Tests.

scholarly journals EXPERIMENTAL ANALYSIS OF THE COMBUSTION CHAMBER COATED WITH Mo AND Al2O3-TiO2 IN A DIESEL ENGINE

2021 ◽  
Vol 55 (4) ◽  
Author(s):  
Murugan Kuppusamy ◽  
Thirumalai Ramanathan ◽  
Udhayakumar Krishnavel ◽  
Seenivasan Murugesan
Keyword(s):  
Combustion Chamber ◽  
Fuel Consumption ◽  
Thermal Efficiency ◽  
Performance Test ◽  
Ceramic Powder ◽  
Specific Fuel Consumption ◽  
Emission Characteristic ◽  
Powder Materials ◽  
Brake Specific Fuel Consumption ◽  
Brake Thermal Efficiency

The effect of thermal-barrier coatings (TBCs) reduces fuel consumption, effectively improving the engine efficiency. This research focused on a TBC with a thickness of 300 µm insulating the combustion chamber of a direct ignition (DI) engine. The piston crown, inlet and exhaust-valve head were coated using air-plasma-spray coating. Ceramic powder materials such as molybdenum (Mo) and aluminum oxide titanium dioxide (Al2O3-TiO2) were used. A performance test of the engine with the coated combustion chamber was carried out to investigate the brake power, brake thermal efficiency, volumetric efficiency, brake specific fuel consumption and air-fuel ratio. Also, an emission-characteristic test was carried out to investigate the emissions of unburned hydrocarbon (HC), carbon monoxide (CO), nitrogen oxides (NO, NO2, NO3) and smoke opacity (SO). The results reveal that the brake thermal efficiency and brake specific fuel consumption show significant increases because of these coating materials. The effect of the Al2O3-TiO2 coating significantly reduces the HC and CO engine emissions.

Influence of Heat Insulation Material on Thermal Stress of Long Nozzle

2012 ◽  
Vol 535-537 ◽  
pp. 1609-1614 ◽  
Author(s):  
Hui Min Liu
Keyword(s):  
Thermal Stress ◽  
Layer Thickness ◽  
Outer Layer ◽  
Heat Insulation ◽  
Outer Wall ◽  
Symmetric Model ◽  
Insulation Material ◽  
Axially Symmetric ◽  
Coefficient Of Thermal Conductivity ◽  
Heat Insulation Material

To prevent a long nozzle (LN) of non-preheating from rupture caused by thermal shock, heat insulation material (HIM) with a lower coefficient of thermal conductivity (CTC) was compounded in the inner hole (inner layer) or around the outer wall (outer layer), and the thermal stress was investigated. The two-dimension axially symmetric model of LN was proposed by simplifying the structure and boundary conditions. The influences of the HIM to the thermal stress of LN were analyzed by finite element method. The results show that the thermal stress suffered by LN can be drastically reduced by the inner layer, making the slow variation, but when its thickness increases from 2 mm to 3 mm, it almost has no influence on the thermal stress. The maximum thermal stress at the neck of LN reduces with the depression of the CTC at the inner layer thickness of 2 mm. The maximum thermal stress of LN can’t be reduced by outer layer, but the lasting time of higher stress can be shortened, and the thermal stress at the later period of steel-irrigating can be lowed. When the outer layer thickness is more than 2 mm, the increase of it has little influence on the thermal stress of LN, and the change of its CTC has little influence on the thermal stress either. The LN with tri-layer has lower thermal stress during all the period of steel-irrigating.

Mukhaizna Steam Injectors Thermal Efficiency & Insulated tubing Pilot Evaluation

2015 ◽  
Author(s):  
Rashid Al Shaibi
Keyword(s):  
Thermal Efficiency ◽  
Outer Wall ◽  
Heat Losses ◽  
Oil Field ◽  
Evaluation Methodology ◽  
Base Line ◽  
Field Observations ◽  
Reference Base ◽  
Steam Flood ◽  
Deep Reservoir

Abstract Occidental operates a steam flood project in Mukhaizna which is a giant deep heavy oil field in south Oman. Wellbore heat losses from steam injectors is one of the challenges that degrades the steam flood thermal efficiency for a deep reservoir. In addition, wellbore heat losses increase the thermal stress on the casing and lead to wellbore damage. In aim to reduce wellbore heat losses, insulated tubing was introduced and a Pilot was carried out to select the optimum insulated tubing product in the market. Ten Injectors were instrumented and completed with insulated tubing from four different vendors in addition to two bare strings used as a reference base line. Data were collected and evaluated in eight months period. Field thermal conductivity was obtained for the tested products using DTS temperature data from the outermost casing, the Thermocouples data from the tubing outer wall and temperature logs during injection in aid of a calibrated wellbore model. The conducted analysis and the field observations were sufficient to resolve the thermal performance between the tested products. This paper describes the Pilot configuration and the evaluation methodology. Analysis output and field observations are summarized and presented in addition to the raw data collected from the instruments and temperature logs.

scholarly journals Innovative Technologies for District Heating and Cooling: InDeal Project

Proceedings ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 1 ◽  
Author(s):  
Serafeim Moustakidis ◽  
Ioannis Meintanis ◽  
Nicos Karkanias ◽  
George Halikias ◽  
Elise Saoutieff ◽  
...  
Keyword(s):  
Energy Demand ◽  
Social Impact ◽  
New Technologies ◽  
District Heating ◽  
Interdisciplinary Approach ◽  
Production Costs ◽  
Plant Production ◽  
Insulation Material ◽  
Innovative Technologies ◽  
Heating And Cooling

The paper discusses the outcomes of the conference organized by the InDeal project. The conference took place on 12 December 2018 in Montpellier as part of the EnerGaia energy forum 2018. A holistic interdisciplinary approach for district heating and cooling (DHC) networks is presented that integrates heterogeneous innovative technologies from various scientific sectors. The solution is based on a multi-layer control and modelling framework that has been designed to minimize the total plant production costs and optimize heating/cooling distribution. Artificial intelligence tools are employed to model uncertainties associated with weather and energy demand forecasts, as well as quantify the energy storage capacity. Smart metering devices are utilized to collect information about all the crucial heat substations’ parameters, whereas a web-based platform offers a unique user environment for network operators. Three new technologies have been further developed to improve the efficiency of pipe design of DHC systems: (i) A new sustainable insulation material for reducing heat losses, (ii) a new quick-fit joint for an easy installation, and (iii) a new coating for reducing pressure head losses. The results of a study on the development and optimization of two energy harvesting systems are also provided. The assessment of the environmental, economic and social impact of the proposed holistic approach is performed through a life cycle analysis. The validation methodology of the integrated solution is also described, whereas conclusions and future work are finally given.

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