Simulation and performance parameter options for the measurement and verification of South African solar water heaters
- Authors: Chan Wing, Shaun
- Date: 2016
- Subjects: Solar thermal energy , Solar water heaters , Solar heating
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/242314 , uj:24989
- Description: M.Ing. (Electrical Engineering) , Abstract: In recent years the DSM residential program has extended itself to include subsidies for solar water heaters. This undertaking is primarily based on the fact that water heating contributes to about 30-50% of a households electricity demand. The National Solar Water Heater Program, encourages residential homeowners to install an approved SABS solar water heater by means of a rebate incentive. The Namibian national power utility NamPower is set to roll out a similar DSM initiative. Often for DSM initiatives, impacts need to be determined with a certain degree of accuracy to ensure the security of the various stakeholders involved. Measurement and Verification (M&V) is a practice where an independent body impartially determines and presents its findings of the impacts of a DSM initiative. The objective of this project looks to correlate the European (EN 12975-2) and American (ASHRAE 93) SWH standards to the South African (SANS 6211) SWH standard. The correlation will focus on finding a relationship between the performance coefficients of equations 9, 10 and 11 that are mentioned in chapter five. This interrelationship should allow PolySun to accurately simulate South African SWH systems that are not found in PolySun’s database. Providing an M&V entity, Utility or SWH consumer the option of simulating SWH systems found in South Africa in PolySun.
- Full Text:
- Authors: Chan Wing, Shaun
- Date: 2016
- Subjects: Solar thermal energy , Solar water heaters , Solar heating
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/242314 , uj:24989
- Description: M.Ing. (Electrical Engineering) , Abstract: In recent years the DSM residential program has extended itself to include subsidies for solar water heaters. This undertaking is primarily based on the fact that water heating contributes to about 30-50% of a households electricity demand. The National Solar Water Heater Program, encourages residential homeowners to install an approved SABS solar water heater by means of a rebate incentive. The Namibian national power utility NamPower is set to roll out a similar DSM initiative. Often for DSM initiatives, impacts need to be determined with a certain degree of accuracy to ensure the security of the various stakeholders involved. Measurement and Verification (M&V) is a practice where an independent body impartially determines and presents its findings of the impacts of a DSM initiative. The objective of this project looks to correlate the European (EN 12975-2) and American (ASHRAE 93) SWH standards to the South African (SANS 6211) SWH standard. The correlation will focus on finding a relationship between the performance coefficients of equations 9, 10 and 11 that are mentioned in chapter five. This interrelationship should allow PolySun to accurately simulate South African SWH systems that are not found in PolySun’s database. Providing an M&V entity, Utility or SWH consumer the option of simulating SWH systems found in South Africa in PolySun.
- Full Text:
Solar irradiance calculations for solar power generating devices operating in South African conditions
- Authors: Webber, Graham
- Date: 2016
- Subjects: Solar radiation - South Africa , Solar thermal energy , Energy development , Photovoltaic power generation
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/235947 , uj:24139
- Description: M.Sc. (Physics) , Abstract: Please refer to full text to view abstract
- Full Text:
- Authors: Webber, Graham
- Date: 2016
- Subjects: Solar radiation - South Africa , Solar thermal energy , Energy development , Photovoltaic power generation
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/235947 , uj:24139
- Description: M.Sc. (Physics) , Abstract: Please refer to full text to view abstract
- Full Text:
Modelling and design of a latent heat thermal storage system with reference to solar absorption refrigeration
- Authors: Kantole, Joseph Basakayi
- Date: 2012-10-24
- Subjects: Solar thermal energy , Heat storage , Heat exchangers
- Type: Thesis
- Identifier: uj:10417 , http://hdl.handle.net/10210/7883
- Description: M.Ing. , The research in this thesis focuses on the theoretical thermal modelling and design of a Latent Heat Storage system (LHS) for an absorption refrigeration machine. A shell-and-tube latent heat storage exchanger retaining any excess solar thermal energy is selected. Here, solar thermal energy supplied by a collector is transferred to and stored by the LHS. During low insolation, stored thermal energy is transferred by a Heat Transfer Fluid (HTF) into the generator, a component of an Ammonia Absorption Refrigerator (AAAR), to ensure efficiency of the cooling cycle. The shell-and-tube LHS contains Phase Change Material (PCM) which fills space outside the tube heat exchangers. The HTF flowing through the tubes exchanges thermal energy with the PCM. The selection of a suitable PCM for a LHS is based on several factors. A primary criterion for an efficient, reliable storage unit is the correct melting point of the PCM at a desired operating temperature of the heating application. An analytical model describing both the freezing process in the PCM and increased HTF temperature in the tube heat exchangers is investigated. The model is developed using energy balance equations. It is solved in terms of dimensionless parameters. The thermal resistance of the tube heat exchangers is considered for this model. From the result of the analytical model, the design approach to size the LHS is provided and the different steps are given in order to determine the volume, mass, number of tube heat exchangers, inner and outer radius of the tube heat exchangers and other parameters of the LHS. The dimensions of LHS are given as a function of a storage period, PCM properties, HTF properties, inner and outer radius of the tube heat exchangers, material of construction of the tube heat exchangers and the nature of load on the heating process. Simulations from the analytical model developed are provided for the output thermal parameters of the storage system. These thermal parameters of the shell-and-tube latent exchanger are given in terms of the HTF outlet temperature, the front solidification of the PCM and the heat transfer rate during the solidification process of the PCM. A case study to demonstrate the application of the design approach with respect to the size shell-and-tube latent heat exchanger is provided.The integration of the tube heat exchangers thermal conductivity in the modelling of the LHS resulted in an increase of 2% in mass of the storage material compared to an analytical model neglecting the thermal conductivity of the tube heat exchangers. The results of the model developed compared well with the results obtained from other analytical models at similar operating conditions.
- Full Text:
- Authors: Kantole, Joseph Basakayi
- Date: 2012-10-24
- Subjects: Solar thermal energy , Heat storage , Heat exchangers
- Type: Thesis
- Identifier: uj:10417 , http://hdl.handle.net/10210/7883
- Description: M.Ing. , The research in this thesis focuses on the theoretical thermal modelling and design of a Latent Heat Storage system (LHS) for an absorption refrigeration machine. A shell-and-tube latent heat storage exchanger retaining any excess solar thermal energy is selected. Here, solar thermal energy supplied by a collector is transferred to and stored by the LHS. During low insolation, stored thermal energy is transferred by a Heat Transfer Fluid (HTF) into the generator, a component of an Ammonia Absorption Refrigerator (AAAR), to ensure efficiency of the cooling cycle. The shell-and-tube LHS contains Phase Change Material (PCM) which fills space outside the tube heat exchangers. The HTF flowing through the tubes exchanges thermal energy with the PCM. The selection of a suitable PCM for a LHS is based on several factors. A primary criterion for an efficient, reliable storage unit is the correct melting point of the PCM at a desired operating temperature of the heating application. An analytical model describing both the freezing process in the PCM and increased HTF temperature in the tube heat exchangers is investigated. The model is developed using energy balance equations. It is solved in terms of dimensionless parameters. The thermal resistance of the tube heat exchangers is considered for this model. From the result of the analytical model, the design approach to size the LHS is provided and the different steps are given in order to determine the volume, mass, number of tube heat exchangers, inner and outer radius of the tube heat exchangers and other parameters of the LHS. The dimensions of LHS are given as a function of a storage period, PCM properties, HTF properties, inner and outer radius of the tube heat exchangers, material of construction of the tube heat exchangers and the nature of load on the heating process. Simulations from the analytical model developed are provided for the output thermal parameters of the storage system. These thermal parameters of the shell-and-tube latent exchanger are given in terms of the HTF outlet temperature, the front solidification of the PCM and the heat transfer rate during the solidification process of the PCM. A case study to demonstrate the application of the design approach with respect to the size shell-and-tube latent heat exchanger is provided.The integration of the tube heat exchangers thermal conductivity in the modelling of the LHS resulted in an increase of 2% in mass of the storage material compared to an analytical model neglecting the thermal conductivity of the tube heat exchangers. The results of the model developed compared well with the results obtained from other analytical models at similar operating conditions.
- Full Text:
Life cycle assessment of solar chimneys
- Van Blommestein, Brandon, Mbowa, Charles
- Authors: Van Blommestein, Brandon , Mbowa, Charles
- Date: 2013
- Subjects: Solar thermal energy , Solar thermal energy - Environmental aspects , Solar chimneys
- Type: Article
- Identifier: uj:6159 , ISBN 978-981-4451-47-5 , http://hdl.handle.net/10210/13763
- Description: Climate change is increasingly becoming a significant issue globally and the use of solar thermal technology is one approach in managing the world’s environment. There is now greater use of renewable energy sources in order to minimize the depletion of energy resources while providing an environmentally-friendly energy source that has minimal impact on the environment. It is thus important to be able to assess the environmental impact of different types of solar thermal technologies in order to have an understanding of the actual impact of solar thermal on the environment. Most solar thermal technologies need to use water in the production process to produce electricity. The most viable place to produce solar energy is in extremely hot climates like deserts where there is not much water to choose from. Most of the time water comes from sources that are far away and becomes expensive to transport the water to the solar plant sites. There is one solar thermal technology that does not require water to produce electricity. It is called Solar Chimney or Solar updraft tower. This paper will assess the environmental impact of Solar Chimneys across its life cycle using the Life Cycle Assessment approach (LCA). The contribution of this paper is providing further understanding of the environmental impact of solar chimneys across its life cycle particularly as new technologies in solar technology continue to be developed.
- Full Text:
- Authors: Van Blommestein, Brandon , Mbowa, Charles
- Date: 2013
- Subjects: Solar thermal energy , Solar thermal energy - Environmental aspects , Solar chimneys
- Type: Article
- Identifier: uj:6159 , ISBN 978-981-4451-47-5 , http://hdl.handle.net/10210/13763
- Description: Climate change is increasingly becoming a significant issue globally and the use of solar thermal technology is one approach in managing the world’s environment. There is now greater use of renewable energy sources in order to minimize the depletion of energy resources while providing an environmentally-friendly energy source that has minimal impact on the environment. It is thus important to be able to assess the environmental impact of different types of solar thermal technologies in order to have an understanding of the actual impact of solar thermal on the environment. Most solar thermal technologies need to use water in the production process to produce electricity. The most viable place to produce solar energy is in extremely hot climates like deserts where there is not much water to choose from. Most of the time water comes from sources that are far away and becomes expensive to transport the water to the solar plant sites. There is one solar thermal technology that does not require water to produce electricity. It is called Solar Chimney or Solar updraft tower. This paper will assess the environmental impact of Solar Chimneys across its life cycle using the Life Cycle Assessment approach (LCA). The contribution of this paper is providing further understanding of the environmental impact of solar chimneys across its life cycle particularly as new technologies in solar technology continue to be developed.
- Full Text:
The modelling of solar radiation quantities and intensities in a two dimensional compound parabolic collector
- Authors: Moodaly, Asogan
- Date: 2010-03-15T06:30:19Z
- Subjects: Solar radiation , Solar energy , Solar thermal energy , Solar collectors design and construction
- Type: Thesis
- Identifier: uj:6671 , http://hdl.handle.net/10210/3076
- Description: M.Ing. , A dissertation presented on the basic solar design principles such as sun-earth geometry, energy wavelengths, optics, incidence angles, parabolic collector configurations and design, materials for solar applications, efficiencies, etc to be considered in Solar Concentrating Collector design. These principles were applied in the design and fabrication of a prototype solar collector. The solar collector was tested to verify and correct mathematical models that were generated from existing literature; as well as for optimization work.
- Full Text:
- Authors: Moodaly, Asogan
- Date: 2010-03-15T06:30:19Z
- Subjects: Solar radiation , Solar energy , Solar thermal energy , Solar collectors design and construction
- Type: Thesis
- Identifier: uj:6671 , http://hdl.handle.net/10210/3076
- Description: M.Ing. , A dissertation presented on the basic solar design principles such as sun-earth geometry, energy wavelengths, optics, incidence angles, parabolic collector configurations and design, materials for solar applications, efficiencies, etc to be considered in Solar Concentrating Collector design. These principles were applied in the design and fabrication of a prototype solar collector. The solar collector was tested to verify and correct mathematical models that were generated from existing literature; as well as for optimization work.
- Full Text:
Calculating the optimum solar panel orientation for Gauteng Province
- Nethwadzi, Lutendo Christopher
- Authors: Nethwadzi, Lutendo Christopher
- Date: 2019
- Subjects: Solar power plants , Solar thermal energy , Photovoltaic power generation , Solar system
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/403573 , uj:33825
- Description: Abstract : This thesis presents the calculation of optimum solar panel orientation for Gauteng Province by adapting known sky transparency models to actual irradiance data. Solar irradiance losses in the atmosphere are traditionally quantified by the Linke turbidity factor. This study analyses the global irradiance measured in Gauteng and attempts to reproduce the data in terms of irradiance models, such as Aras et al (2006) model, Tsubo et al (2003) model, Scharmer and Greif (2000) model and the Slob Algorithm (2006) model. Some of these models were adapted for local atmospheric conditions, except for the Aras et al (2006) model and the Scharmer and Greif (2000) model. The irradiance energy yields of a solar panel were mod- elled taking into account orientation, season, time of day, and atmospheric losses. The analysis models the irradiance using the Linke turbidity factor. This considers the estimation of the direct component and the diffuse component, which are then summed with an effort to match the measured irradiance and modelled irradiance yield. The Linke turbidities determined in this manner are then compared with corresponding values given in an online solar irradiance calculation tool called PVGIS... , M.Sc. (Physics)
- Full Text:
- Authors: Nethwadzi, Lutendo Christopher
- Date: 2019
- Subjects: Solar power plants , Solar thermal energy , Photovoltaic power generation , Solar system
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/403573 , uj:33825
- Description: Abstract : This thesis presents the calculation of optimum solar panel orientation for Gauteng Province by adapting known sky transparency models to actual irradiance data. Solar irradiance losses in the atmosphere are traditionally quantified by the Linke turbidity factor. This study analyses the global irradiance measured in Gauteng and attempts to reproduce the data in terms of irradiance models, such as Aras et al (2006) model, Tsubo et al (2003) model, Scharmer and Greif (2000) model and the Slob Algorithm (2006) model. Some of these models were adapted for local atmospheric conditions, except for the Aras et al (2006) model and the Scharmer and Greif (2000) model. The irradiance energy yields of a solar panel were mod- elled taking into account orientation, season, time of day, and atmospheric losses. The analysis models the irradiance using the Linke turbidity factor. This considers the estimation of the direct component and the diffuse component, which are then summed with an effort to match the measured irradiance and modelled irradiance yield. The Linke turbidities determined in this manner are then compared with corresponding values given in an online solar irradiance calculation tool called PVGIS... , M.Sc. (Physics)
- Full Text:
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