A systems thinking approach to collaborations for capacity building and sustainability in engineering education
- Nyemba, Wilson R., Carter, Keith F., Mbohwa, Charles, Chinguwa, Simon
- Authors: Nyemba, Wilson R. , Carter, Keith F. , Mbohwa, Charles , Chinguwa, Simon
- Date: 2019
- Subjects: Capacity building , Industry-academia partnerships , Engineering education
- Language: English
- Type: Articles
- Identifier: http://hdl.handle.net/10210/295135 , uj:32129 , Citation: Nyemba, W.R. et al. 2019. A systems thinking approach to collaborations for capacity building and sustainability in engineering education.
- Description: Abstract: Please refer to full text to view abstract.
- Full Text:
- Authors: Nyemba, Wilson R. , Carter, Keith F. , Mbohwa, Charles , Chinguwa, Simon
- Date: 2019
- Subjects: Capacity building , Industry-academia partnerships , Engineering education
- Language: English
- Type: Articles
- Identifier: http://hdl.handle.net/10210/295135 , uj:32129 , Citation: Nyemba, W.R. et al. 2019. A systems thinking approach to collaborations for capacity building and sustainability in engineering education.
- Description: Abstract: Please refer to full text to view abstract.
- Full Text:
Conceptualization of the optimal design of a hydroxyl booster dry cell for enhancing efficiency of internal combustion engines
- Chinguwa, Simon, Jen, Tien-Chien, Akinlabi, Esther T.
- Authors: Chinguwa, Simon , Jen, Tien-Chien , Akinlabi, Esther T.
- Date: 2020
- Subjects: Dry cell , Hydroxyl , Internal combusion
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/437148 , uj:37948 , Citation: Chinguwa, S., Jen, T.C. & Akinlabi, E.T. 2020. Conceptualization of the optimal design of a hydroxyl booster dry cell for enhancing efficiency of internal combustion engines.
- Description: Abstract: Current internal combustion engines (ICEs) are powered by fossil fuels which create the challenges of low combustion efficiency and the emission of greenhouse gases. This has negatively affected the environment, leading to global warming and climate change. Interim technologies can be implemented to reduce these effects whilst alternative technologies are being explored. This research aimed at selecting the most appropriate geometrical design of a hydroxyl booster dry cell, a device which operates on the principles of electrolysis to produce hydroxyl gas commonly referred to as Brown gas or HHO. When a voltage is applied to a body of water, it splits it into its base components, i.e. hydrogen and oxygen cold plasma, a mixture sometimes referred to as hydroxyl gas. The addition of hydroxyl gas into the combustion chamber of an ICE initiates a more complete combustion due to the explosive and diffusive nature of hydrogen accompanied by the cooling effect of water thus reducing potential for NOx formation. This leads to fuel savings, cost savings and reduced emissions. A rectangular hydroxyl booster dry cell was selected and designed, fabricated and tested for effectiveness. The HHO generator is later connected to the ICE system to check mainly on the positive contributions of this Brown’s gas as HHO is popularly known.
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- Authors: Chinguwa, Simon , Jen, Tien-Chien , Akinlabi, Esther T.
- Date: 2020
- Subjects: Dry cell , Hydroxyl , Internal combusion
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/437148 , uj:37948 , Citation: Chinguwa, S., Jen, T.C. & Akinlabi, E.T. 2020. Conceptualization of the optimal design of a hydroxyl booster dry cell for enhancing efficiency of internal combustion engines.
- Description: Abstract: Current internal combustion engines (ICEs) are powered by fossil fuels which create the challenges of low combustion efficiency and the emission of greenhouse gases. This has negatively affected the environment, leading to global warming and climate change. Interim technologies can be implemented to reduce these effects whilst alternative technologies are being explored. This research aimed at selecting the most appropriate geometrical design of a hydroxyl booster dry cell, a device which operates on the principles of electrolysis to produce hydroxyl gas commonly referred to as Brown gas or HHO. When a voltage is applied to a body of water, it splits it into its base components, i.e. hydrogen and oxygen cold plasma, a mixture sometimes referred to as hydroxyl gas. The addition of hydroxyl gas into the combustion chamber of an ICE initiates a more complete combustion due to the explosive and diffusive nature of hydrogen accompanied by the cooling effect of water thus reducing potential for NOx formation. This leads to fuel savings, cost savings and reduced emissions. A rectangular hydroxyl booster dry cell was selected and designed, fabricated and tested for effectiveness. The HHO generator is later connected to the ICE system to check mainly on the positive contributions of this Brown’s gas as HHO is popularly known.
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Development and fabrication of a wood gasifier to power an internal combustion engine
- Chinguwa, Simon, Nyemba, Wilson R., Jen, Tien-Chien, Boora, Kudzai
- Authors: Chinguwa, Simon , Nyemba, Wilson R. , Jen, Tien-Chien , Boora, Kudzai
- Date: 2018
- Subjects: Carbon , Combustion , Fossil Fuels
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/285610 , uj:30890 , Citation: Chinguwa, S. et al. 2018. Development and fabrication of a wood gasifier to power an internal combustion engine.
- Description: Abstract: Fossil fuels have been the main source of energy for many years hence the depletion of resource. There is therefore a need for alternative cleaner energy sources of fuel to be explored. The use of these conventional fuels led to land degradation global warming and air pollution. A wood gasifier machine which produces combustible gas from solid fuels like charcoal, wood and agriculture residue was designed. The combustible gas can be used for heating purposes or to produce mechanical or electrical energy. There was a great literature search for the technology currently being used for gasification processes which led to the design and manufacture of the gasifier prototype which was tested and came out successfully. An internal combustion engine was run on the combustible gas. Gasification bi-products that came out were tar and ash which could be used for water proofing and fertilizer respectively. Biofuels are renewable energy sources and are carbon neutral as they do not increase the total amount carbon dioxide in the atmosphere. The test also revealed some shortcomings in the design. The air which was used to allow for combustion to take place was inadequate, hence there is a need for further research.
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- Authors: Chinguwa, Simon , Nyemba, Wilson R. , Jen, Tien-Chien , Boora, Kudzai
- Date: 2018
- Subjects: Carbon , Combustion , Fossil Fuels
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/285610 , uj:30890 , Citation: Chinguwa, S. et al. 2018. Development and fabrication of a wood gasifier to power an internal combustion engine.
- Description: Abstract: Fossil fuels have been the main source of energy for many years hence the depletion of resource. There is therefore a need for alternative cleaner energy sources of fuel to be explored. The use of these conventional fuels led to land degradation global warming and air pollution. A wood gasifier machine which produces combustible gas from solid fuels like charcoal, wood and agriculture residue was designed. The combustible gas can be used for heating purposes or to produce mechanical or electrical energy. There was a great literature search for the technology currently being used for gasification processes which led to the design and manufacture of the gasifier prototype which was tested and came out successfully. An internal combustion engine was run on the combustible gas. Gasification bi-products that came out were tar and ash which could be used for water proofing and fertilizer respectively. Biofuels are renewable energy sources and are carbon neutral as they do not increase the total amount carbon dioxide in the atmosphere. The test also revealed some shortcomings in the design. The air which was used to allow for combustion to take place was inadequate, hence there is a need for further research.
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Development of an effective self-cleaning system to minimize fouling in heat exchangers
- Nyemba, Wilson R., Chinguwa, Simon, Zimba, Isheanesu, Mbohwa, Charles
- Authors: Nyemba, Wilson R. , Chinguwa, Simon , Zimba, Isheanesu , Mbohwa, Charles
- Date: 2018
- Subjects: Condenser , Fouling , Foulant
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/285603 , uj:30889 , Citation: Nyemba, W.R. et al. 2018. Development of an effective self-cleaning system to minimize fouling in heat exchangers.
- Description: Abstract: Power plant steam condensers use cooling water for condensation of exhaust steam from turbines. Depending on the concentration of cations in the cooling water, changes in temperature result in the precipitation of insoluble metal salts on the tube walls hence impeding heat transfer, leading to fouling, a threat on the heat transfer efficiency of the condenser. The research was carried out at a power station in Zimbabwe where offline mechanical methods used to clean the tubes were observed to be slow and inefficient, hence increasing downtimes. The use of spherical rubber balls was proposed where they were injected into the cooling water to scrub off dirt on the tube surfaces as well as creating turbulence to prevent the dirt from settling on the tube walls. Ball sizes of diameter less than the tube sizes were preferred in order to cater for possible thermal expansion of the rubber material on exposure to elevated temperatures. A magnetic water treatment unit was added to facilitate the formation of weak precipitates of the metal salts for ease of removal on cleaning. The design and implementation of the research results had the potential of saving the company on downtimes during condenser cleaning.
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- Authors: Nyemba, Wilson R. , Chinguwa, Simon , Zimba, Isheanesu , Mbohwa, Charles
- Date: 2018
- Subjects: Condenser , Fouling , Foulant
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/285603 , uj:30889 , Citation: Nyemba, W.R. et al. 2018. Development of an effective self-cleaning system to minimize fouling in heat exchangers.
- Description: Abstract: Power plant steam condensers use cooling water for condensation of exhaust steam from turbines. Depending on the concentration of cations in the cooling water, changes in temperature result in the precipitation of insoluble metal salts on the tube walls hence impeding heat transfer, leading to fouling, a threat on the heat transfer efficiency of the condenser. The research was carried out at a power station in Zimbabwe where offline mechanical methods used to clean the tubes were observed to be slow and inefficient, hence increasing downtimes. The use of spherical rubber balls was proposed where they were injected into the cooling water to scrub off dirt on the tube surfaces as well as creating turbulence to prevent the dirt from settling on the tube walls. Ball sizes of diameter less than the tube sizes were preferred in order to cater for possible thermal expansion of the rubber material on exposure to elevated temperatures. A magnetic water treatment unit was added to facilitate the formation of weak precipitates of the metal salts for ease of removal on cleaning. The design and implementation of the research results had the potential of saving the company on downtimes during condenser cleaning.
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Development of an electric drive train for cycles as a sustainable means of transportation for a green environment
- Chinguwa, Simon, Nyemba, Wilson R., Ngondo, Emmanuel, Mbohwa, Charles
- Authors: Chinguwa, Simon , Nyemba, Wilson R. , Ngondo, Emmanuel , Mbohwa, Charles
- Date: 2019
- Subjects: Electric drive train , Manufacture , Transmission
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/295143 , uj:32130 , Citation: Chinguwa, S. et al. 2019. Development of an electric drive train for cycles as a sustainable means of transportation for a green environment.
- Description: Abstract: A reliable and sustainable means of human transportation is vital for the world’s increasing pollution emissions and congestions on the motorways. The research aimed at and focused on developing an affordable electric drive train for cycles using the principle of Continuously Variable Transmission (CVT) to provide an interminable number of speed ratios by varying the pulley diameters. The planetary gears designed and installed within the CVT chamber provided a locking mechanism for the ring gear to provide forward transmission to the rear wheel where motion was stepped up through an open differential gear to propel the cycle forward. For stability and ease of manufacture and assembly, a tricycle concept was chosen and developed as a sustainable and alternative means of transportation. The developed electric drive train provides a ‘green’ and affordable means of human transportation in a world geared towards the elimination of pollution.
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- Authors: Chinguwa, Simon , Nyemba, Wilson R. , Ngondo, Emmanuel , Mbohwa, Charles
- Date: 2019
- Subjects: Electric drive train , Manufacture , Transmission
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/295143 , uj:32130 , Citation: Chinguwa, S. et al. 2019. Development of an electric drive train for cycles as a sustainable means of transportation for a green environment.
- Description: Abstract: A reliable and sustainable means of human transportation is vital for the world’s increasing pollution emissions and congestions on the motorways. The research aimed at and focused on developing an affordable electric drive train for cycles using the principle of Continuously Variable Transmission (CVT) to provide an interminable number of speed ratios by varying the pulley diameters. The planetary gears designed and installed within the CVT chamber provided a locking mechanism for the ring gear to provide forward transmission to the rear wheel where motion was stepped up through an open differential gear to propel the cycle forward. For stability and ease of manufacture and assembly, a tricycle concept was chosen and developed as a sustainable and alternative means of transportation. The developed electric drive train provides a ‘green’ and affordable means of human transportation in a world geared towards the elimination of pollution.
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Evaluation and feasibility assessment of the sustainability of refrigeration systems devoid of harmful refrigerants for storage of vaccines
- Nyemba, Wilson R., Chinguwa, Simon, Marango, Batsirayi L., Mbohwa, Charles
- Authors: Nyemba, Wilson R. , Chinguwa, Simon , Marango, Batsirayi L. , Mbohwa, Charles
- Date: 2019
- Subjects: CFCs , Refrigerant , Refrigeration
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/402341 , uj:33665 , Citation: Nyemba, W.R. et al. 2019. Evaluation and feasibility assessment of the sustainability of refrigeration systems devoid of harmful refrigerants for storage of vaccines. Procedia Manufacturing, 35:291–297. https://doi.org/10.1016/j.promfg.2019.05.042
- Description: Abstract: Conventional refrigerators impact on the environment contributing to ozone depletion and global warming. Common refrigeration methods make use of Chlorofluorocarbons (CFCs), Hydro chlorofluorocarbons (HCFCs) and Hydrofluorocarbons (HFCs) which all have negative effects on the environment. Legislation in some countries has been enforced to ban the use of some refrigerants due to their harmful effects. It was therefore prudent to develop alternative methods of refrigeration such as thermos-acoustic, magnetic or thermoelectric that do not utilise the harmful refrigerants. Alternative refrigeration methods can be applied in a variety of industries such as the food, agriculture and health establishments. This research established the disadvantages of conventional refrigeration and the potential for alternative refrigeration methods for the storage of vaccines. A portable thermoelectric prototype refrigerator was developed from locally available and sustainable materials at an estimated cost of $129. Although its performance was below that of conventional refrigerators, it managed to accomplish the desirable range of temperature for storing and transportation of vaccines, positively impacting on the environment by avoiding the harmful effects of refrigerants.
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- Authors: Nyemba, Wilson R. , Chinguwa, Simon , Marango, Batsirayi L. , Mbohwa, Charles
- Date: 2019
- Subjects: CFCs , Refrigerant , Refrigeration
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/402341 , uj:33665 , Citation: Nyemba, W.R. et al. 2019. Evaluation and feasibility assessment of the sustainability of refrigeration systems devoid of harmful refrigerants for storage of vaccines. Procedia Manufacturing, 35:291–297. https://doi.org/10.1016/j.promfg.2019.05.042
- Description: Abstract: Conventional refrigerators impact on the environment contributing to ozone depletion and global warming. Common refrigeration methods make use of Chlorofluorocarbons (CFCs), Hydro chlorofluorocarbons (HCFCs) and Hydrofluorocarbons (HFCs) which all have negative effects on the environment. Legislation in some countries has been enforced to ban the use of some refrigerants due to their harmful effects. It was therefore prudent to develop alternative methods of refrigeration such as thermos-acoustic, magnetic or thermoelectric that do not utilise the harmful refrigerants. Alternative refrigeration methods can be applied in a variety of industries such as the food, agriculture and health establishments. This research established the disadvantages of conventional refrigeration and the potential for alternative refrigeration methods for the storage of vaccines. A portable thermoelectric prototype refrigerator was developed from locally available and sustainable materials at an estimated cost of $129. Although its performance was below that of conventional refrigerators, it managed to accomplish the desirable range of temperature for storing and transportation of vaccines, positively impacting on the environment by avoiding the harmful effects of refrigerants.
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Feasibility study and development of a sustainable solar thermal power plant through utilization of mine wastelands
- Nyemba, Wilson R., Munanga, Prominent, Mbohwa, Charles, Chinguwa, Simon
- Authors: Nyemba, Wilson R. , Munanga, Prominent , Mbohwa, Charles , Chinguwa, Simon
- Date: 2018
- Subjects: System advisor model , Simulation , Solar thermal
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/260423 , uj:27422 , Citation: Nyemba, W.R. et al. 2018. Feasibility study and development of a sustainable solar thermal power plant through utilization of mine wastelands.
- Description: Abstract: Southern Africa has been grappling with power shortages over the last decade due to reduced generating capacities from the region’s few hydroelectric power plants and depleted coal reserves for thermal power generation. This forced many companies to operate below capacity, although potential and resources abound. Research was carried out at one of Zimbabwe’s platinum mining and mineral processing companies to utilize the vast surrounding wastelands with abundant exposure to sunshine throughout the year to augment supplies from the national grid. A spreadsheet model was developed to derive various parameters such as beam radiation, thermal to electric plant efficiency and optimum temperature to determine the heat output incident on collectors. The System Advisor Model (SAM) was then used to simulate the values to determine the arrangement of collectors on the proposed solar thermal tower power plant as well as cost the project. Simulation of the model showed that the designed solar thermal plant can generate 30 MW, a sustainable and feasible output to supplement supplies from the national grid.
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- Authors: Nyemba, Wilson R. , Munanga, Prominent , Mbohwa, Charles , Chinguwa, Simon
- Date: 2018
- Subjects: System advisor model , Simulation , Solar thermal
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/260423 , uj:27422 , Citation: Nyemba, W.R. et al. 2018. Feasibility study and development of a sustainable solar thermal power plant through utilization of mine wastelands.
- Description: Abstract: Southern Africa has been grappling with power shortages over the last decade due to reduced generating capacities from the region’s few hydroelectric power plants and depleted coal reserves for thermal power generation. This forced many companies to operate below capacity, although potential and resources abound. Research was carried out at one of Zimbabwe’s platinum mining and mineral processing companies to utilize the vast surrounding wastelands with abundant exposure to sunshine throughout the year to augment supplies from the national grid. A spreadsheet model was developed to derive various parameters such as beam radiation, thermal to electric plant efficiency and optimum temperature to determine the heat output incident on collectors. The System Advisor Model (SAM) was then used to simulate the values to determine the arrangement of collectors on the proposed solar thermal tower power plant as well as cost the project. Simulation of the model showed that the designed solar thermal plant can generate 30 MW, a sustainable and feasible output to supplement supplies from the national grid.
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Feasibility study of the materials handling and development of a sustainable conveying system in plastics recycling and manufacture
- Chinguwa, Simon, Nyemba, Wilson R., Boora, Kudzai, Mbohwa, Charles
- Authors: Chinguwa, Simon , Nyemba, Wilson R. , Boora, Kudzai , Mbohwa, Charles
- Date: 2019
- Subjects: Conveyor , Materials handling , Plastic manufacturing
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/295162 , uj:32133 , Citation: Chinguwa, S. et al. 2019. Feasibility study of the materials handling and development of a sustainable conveying system in plastics recycling and manufacture.
- Description: Abstract: The appropriate handling of materials in manufacturing is essential for the realization of reductions in direct and indirect costs. This research was carried out at a plastic manufacturing company in Zimbabwe where polymer pellets are used to produce plastic packaging. An in-depth work study was carried out at the plant followed by the feasibility, review and analysis of available and affordable conveying systems. A semi-automated pneumatic conveyor system comprising of a prime mover, feeder, and mixer was designed to replace the manual handling of materials. The analysis and eventual development of the optimal conveying system assisted the company in not only freeing up space for the uninterrupted movement of materials, but also improvements in safety and reduction in transportation and operational costs for the sustainable recycling and manufacture of plastic packaging. The research also contributed to the company’s product quality and variability.
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- Authors: Chinguwa, Simon , Nyemba, Wilson R. , Boora, Kudzai , Mbohwa, Charles
- Date: 2019
- Subjects: Conveyor , Materials handling , Plastic manufacturing
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/295162 , uj:32133 , Citation: Chinguwa, S. et al. 2019. Feasibility study of the materials handling and development of a sustainable conveying system in plastics recycling and manufacture.
- Description: Abstract: The appropriate handling of materials in manufacturing is essential for the realization of reductions in direct and indirect costs. This research was carried out at a plastic manufacturing company in Zimbabwe where polymer pellets are used to produce plastic packaging. An in-depth work study was carried out at the plant followed by the feasibility, review and analysis of available and affordable conveying systems. A semi-automated pneumatic conveyor system comprising of a prime mover, feeder, and mixer was designed to replace the manual handling of materials. The analysis and eventual development of the optimal conveying system assisted the company in not only freeing up space for the uninterrupted movement of materials, but also improvements in safety and reduction in transportation and operational costs for the sustainable recycling and manufacture of plastic packaging. The research also contributed to the company’s product quality and variability.
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Optimization of the design and manufacture of a solar-wind hybrid street light
- Nyemba, Wilson R., Chinguwa, Simon, Mushanguri, Innocent, Mbohwa, Charles
- Authors: Nyemba, Wilson R. , Chinguwa, Simon , Mushanguri, Innocent , Mbohwa, Charles
- Date: 2019
- Subjects: Diffuser , Photovoltaic module , Renewable energy
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/402349 , uj:33666 , Citation: Nyemba, W.R. et al. 2019. Optimization of the design and manufacture of a solar-wind hybrid street light. Procedia Manufacturing, 35:285–290. https://doi.org/10.1016/j.promfg.2019.05.041
- Description: Abstract: The demand for electricity has escalated and cannot be fulfilled by conventional energy sources alone. There has been a rising demand to seek new renewable energy sources. Although solar and wind energy are the most cost effective renewable energy sources, they are unreliable due to the sporadic nature of their occurrence, if implemented as standalones. In Zimbabwe, solar street lighting has been implemented since 2014 as a solution to the erratic power supplies and outages. Wind potential in Zimbabwe has been identified at elevated heights, with Gweru having the maximum power density of 115 W/m2 at 50 m hub height. This paper presents the optimization of the design of a hybrid renewable energy system (HRES) of solar and wind energy to power a 160W streetlight. The system consisted of a wind turbine, photovoltaic modules, charge controller, battery bank and lights. The system sizing was done in Excel using wind and solar data obtained from the database, HOMER Software Package and PVSyst. The 3D streetlight was modelled using Inventor Professional and a working prototype was manufactured. The results showed that the HRES reduced the energy storage requirements by 38.75% with an overall cost reduction of 14.4%, relative to a standalone solar streetlight. The diffuser effect to the turbine was experimentally assessed, showing 69.3% increase in turbine power output and a 50% decrease in energy storage requirements. Further research can be carried to improve the reliability for standalone systems.
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- Authors: Nyemba, Wilson R. , Chinguwa, Simon , Mushanguri, Innocent , Mbohwa, Charles
- Date: 2019
- Subjects: Diffuser , Photovoltaic module , Renewable energy
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/402349 , uj:33666 , Citation: Nyemba, W.R. et al. 2019. Optimization of the design and manufacture of a solar-wind hybrid street light. Procedia Manufacturing, 35:285–290. https://doi.org/10.1016/j.promfg.2019.05.041
- Description: Abstract: The demand for electricity has escalated and cannot be fulfilled by conventional energy sources alone. There has been a rising demand to seek new renewable energy sources. Although solar and wind energy are the most cost effective renewable energy sources, they are unreliable due to the sporadic nature of their occurrence, if implemented as standalones. In Zimbabwe, solar street lighting has been implemented since 2014 as a solution to the erratic power supplies and outages. Wind potential in Zimbabwe has been identified at elevated heights, with Gweru having the maximum power density of 115 W/m2 at 50 m hub height. This paper presents the optimization of the design of a hybrid renewable energy system (HRES) of solar and wind energy to power a 160W streetlight. The system consisted of a wind turbine, photovoltaic modules, charge controller, battery bank and lights. The system sizing was done in Excel using wind and solar data obtained from the database, HOMER Software Package and PVSyst. The 3D streetlight was modelled using Inventor Professional and a working prototype was manufactured. The results showed that the HRES reduced the energy storage requirements by 38.75% with an overall cost reduction of 14.4%, relative to a standalone solar streetlight. The diffuser effect to the turbine was experimentally assessed, showing 69.3% increase in turbine power output and a 50% decrease in energy storage requirements. Further research can be carried to improve the reliability for standalone systems.
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Process flow modelling and optimization of a foundry layout in Zimbabwe using simulation
- Nyemba, Wilson R., Mhlanga, Ruvimbo, Chinguwa, Simon, Mbohwa, Charles
- Authors: Nyemba, Wilson R. , Mhlanga, Ruvimbo , Chinguwa, Simon , Mbohwa, Charles
- Date: 2017
- Subjects: Foundry , Layout , Modelling
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/257770 , uj:27087 , Citation: Nyemba, W.R. et al. 2017. Process flow modelling and optimization of a foundry layout in Zimbabwe using simulation. Proceedings of the 2017 International Symposium on Industrial Engineering and Operations Management (IEOM) Bristol, UK, July 24-25, 2017.
- Description: Abstract: Foundry industry technologies have evolved over the years largely due to rapid changes in technology resulting in complexities that require careful planning and organization. Materials in the foundry industry pass through various stages and a number of factors, ranging from preparation of charges, materials handling and routing, furnace and production scheduling influence the process flows through these interconnected stages. Such a complex network of activities pose some challenges to companies that traditionally employ manual means of production planning. Research was carried out at one of Zimbabwe’s largest foundry companies, prompted by the company’s failure to produce affordable grinding media on time and in turn forcing their main customers to prefer cheaper imports. The work study revealed that the company’s key challenges were in materials handling and transportation distances through the various workstations. This research focused on modelling the process flows using simulation with the aim of optimizing and reorganizing the foundry layout to reduce production costs, improve productivity and enhance efficiency. The resulting model of the optimal layout and process flows has been adopted and the company is gradually regaining its competitiveness and market share.
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- Authors: Nyemba, Wilson R. , Mhlanga, Ruvimbo , Chinguwa, Simon , Mbohwa, Charles
- Date: 2017
- Subjects: Foundry , Layout , Modelling
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/257770 , uj:27087 , Citation: Nyemba, W.R. et al. 2017. Process flow modelling and optimization of a foundry layout in Zimbabwe using simulation. Proceedings of the 2017 International Symposium on Industrial Engineering and Operations Management (IEOM) Bristol, UK, July 24-25, 2017.
- Description: Abstract: Foundry industry technologies have evolved over the years largely due to rapid changes in technology resulting in complexities that require careful planning and organization. Materials in the foundry industry pass through various stages and a number of factors, ranging from preparation of charges, materials handling and routing, furnace and production scheduling influence the process flows through these interconnected stages. Such a complex network of activities pose some challenges to companies that traditionally employ manual means of production planning. Research was carried out at one of Zimbabwe’s largest foundry companies, prompted by the company’s failure to produce affordable grinding media on time and in turn forcing their main customers to prefer cheaper imports. The work study revealed that the company’s key challenges were in materials handling and transportation distances through the various workstations. This research focused on modelling the process flows using simulation with the aim of optimizing and reorganizing the foundry layout to reduce production costs, improve productivity and enhance efficiency. The resulting model of the optimal layout and process flows has been adopted and the company is gradually regaining its competitiveness and market share.
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Waste heat and energy recovery system from smelter off-gas for a platinum processing plant
- Nyemba, Wilson R., Mushanguri, Innocent, Chinguwa, Simon, Mbohwa, Charles
- Authors: Nyemba, Wilson R. , Mushanguri, Innocent , Chinguwa, Simon , Mbohwa, Charles
- Date: 2017
- Subjects: Energy , Heat , Recovery
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/257785 , uj:27088 , Citation: Nyemba, W.R. et al. 2017. Waste heat and energy recovery system from smelter off-gas for a platinum processing plant. Proceedings of the 2017 International Symposium on Industrial Engineering and Operations Management (IEOM) Bristol, UK, July 24-25, 2017.
- Description: Abstract: Most mineral processing companies are energy intensive especially if smelting is used in extraction. After processing, the energy is correspondingly dissipated as heat and toxic gases, requiring stringent controls for sustainability and safety. In recent years, Southern Africa has grappled with power shortages resulting in the scaling down of company operations. Increases in manufacturing activities demand for more energy but this has evidently outstripped supply due to the depletion of natural resources. Mineral processing industries are probably the worst affected due to fluctuations in world metal prices. These challenges require sustainable production strategies to remain in business. This research was carried out at a platinum processing company in Zimbabwe which uses smelting in extractive metallurgy, consuming millions of dollars in energy but also dissipating this as heat and furnace exhaust gases. The focus of the research was on finding ways to turn these challenges into opportunities by recovering the heat and using it for other purposes. A waste heat and energy recovery system was designed to work in conjunction with the smelters and electrostatic precipitator. The proposed system is expected to increase furnace efficiency by 8.5% with an anticipated output of 1.033 MW and an overall plant efficiency of 22.7%.
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- Authors: Nyemba, Wilson R. , Mushanguri, Innocent , Chinguwa, Simon , Mbohwa, Charles
- Date: 2017
- Subjects: Energy , Heat , Recovery
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/257785 , uj:27088 , Citation: Nyemba, W.R. et al. 2017. Waste heat and energy recovery system from smelter off-gas for a platinum processing plant. Proceedings of the 2017 International Symposium on Industrial Engineering and Operations Management (IEOM) Bristol, UK, July 24-25, 2017.
- Description: Abstract: Most mineral processing companies are energy intensive especially if smelting is used in extraction. After processing, the energy is correspondingly dissipated as heat and toxic gases, requiring stringent controls for sustainability and safety. In recent years, Southern Africa has grappled with power shortages resulting in the scaling down of company operations. Increases in manufacturing activities demand for more energy but this has evidently outstripped supply due to the depletion of natural resources. Mineral processing industries are probably the worst affected due to fluctuations in world metal prices. These challenges require sustainable production strategies to remain in business. This research was carried out at a platinum processing company in Zimbabwe which uses smelting in extractive metallurgy, consuming millions of dollars in energy but also dissipating this as heat and furnace exhaust gases. The focus of the research was on finding ways to turn these challenges into opportunities by recovering the heat and using it for other purposes. A waste heat and energy recovery system was designed to work in conjunction with the smelters and electrostatic precipitator. The proposed system is expected to increase furnace efficiency by 8.5% with an anticipated output of 1.033 MW and an overall plant efficiency of 22.7%.
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