Julian Osorio, Tugba Sensoy, Alejandro Rivera, Gustavo A Patino-jaramillo, Juan C Ordonez
Abstract The influence of correlations on the thermal performance modeling of parabolic trough collectors was analyzed in this work. A versatile model for a parabolic trough collector was developed that allows one- and two-dimensional analysis and enables the use of correlations to calculate thermophysical properties and convection heat transfer coefficients. The model also allows the use of constant values for properties and/or coefficients obtained from the evaluation correlations at a specific temperature. The effect of each correlation was evaluated independently, and the results were compared with a reference case that considered a two-dimensional approach and used all the correlations. For the analyzed cases, the correlation for the absorber emittance has the strongest impact on the collector efficiency, leading to a lower error when used. Based on the results, a one-dimensional model approach considering a correlation for the absorber emittance leads to efficiency errors below 3% for collector lengths of up to 243.6 m. Compared with the reference case, a one-dimensional approach using all correlations for a collector with a length of 500 m, and operating with an inlet temperature of 773 K, can result in errors around 9%. However, using constant values for properties and heat transfer coefficients could lead to errors of up to 50%. Multiple thermal models for parabolic trough collectors proposed in the literature rely on a one-dimensional approach, estimated values for the heat transfer coefficients, and constant thermophysical properties. The errors associated with those approaches are analyzed and quantified in this work as a function of the collector length and operation temperature.
{"title":"Influence of Correlations on the Thermal Performance Modeling of Parabolic Trough Collectors","authors":"Julian Osorio, Tugba Sensoy, Alejandro Rivera, Gustavo A Patino-jaramillo, Juan C Ordonez","doi":"10.1115/1.4062170","DOIUrl":"https://doi.org/10.1115/1.4062170","url":null,"abstract":"Abstract The influence of correlations on the thermal performance modeling of parabolic trough collectors was analyzed in this work. A versatile model for a parabolic trough collector was developed that allows one- and two-dimensional analysis and enables the use of correlations to calculate thermophysical properties and convection heat transfer coefficients. The model also allows the use of constant values for properties and/or coefficients obtained from the evaluation correlations at a specific temperature. The effect of each correlation was evaluated independently, and the results were compared with a reference case that considered a two-dimensional approach and used all the correlations. For the analyzed cases, the correlation for the absorber emittance has the strongest impact on the collector efficiency, leading to a lower error when used. Based on the results, a one-dimensional model approach considering a correlation for the absorber emittance leads to efficiency errors below 3% for collector lengths of up to 243.6 m. Compared with the reference case, a one-dimensional approach using all correlations for a collector with a length of 500 m, and operating with an inlet temperature of 773 K, can result in errors around 9%. However, using constant values for properties and heat transfer coefficients could lead to errors of up to 50%. Multiple thermal models for parabolic trough collectors proposed in the literature rely on a one-dimensional approach, estimated values for the heat transfer coefficients, and constant thermophysical properties. The errors associated with those approaches are analyzed and quantified in this work as a function of the collector length and operation temperature.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136265185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Despite the significant potential of solar thermochemical process technology for storing solar energy as solid-state solar fuel, several challenges have made its industrial application difficult. It is important to note that solar energy has a transient nature that causes instability and reduces process efficiency. Therefore, it is crucial to implement a robust control system to regulate the process temperature and tackle the shortage of incoming solar energy during cloudy weather. In our previous works, different model–based control strategies were developed namely a Proportional Integral Derivative controller (PID) with gain scheduling and adaptive Model Predictive Control (MPC). These methods were tested numerically to regulate the temperature inside a high temperature tubular solar reactor. In this work, the proposed control strategies were experimentally tested under various operation conditions. The controllers were challenged to track different setpoints (500oC, 1000oC, and 1450oC) with different amounts of gas/particles flowrates. Additionally, the flow controller was tested to regulate the reactor temperature under a cloudy weather scenario. The ultimate goal was to produced 5 kg of reduced solar fuel magnesium manganese oxide (MgMn2O4) successfully, and the controllers were able to track the required process temperature and reject disturbances despite the system's strong nonlinearity. The experimental results showed a maximum error in the temperature setpoint of less than 0.5% (6°C), and the MPC controller demonstrated superior performance in reducing the control effort and rejecting disturbances.
{"title":"EXPERIMENTAL PERFORMANCE OF A NONLINEAR CONTROL STRATEGY TO REGULATE TEMPERATURE OF A HIGH TEMPERATURE SOLAR REACTOR","authors":"Assaad Alsahlani, Nesrin Ozalp","doi":"10.1115/1.4062483","DOIUrl":"https://doi.org/10.1115/1.4062483","url":null,"abstract":"\u0000 Despite the significant potential of solar thermochemical process technology for storing solar energy as solid-state solar fuel, several challenges have made its industrial application difficult. It is important to note that solar energy has a transient nature that causes instability and reduces process efficiency. Therefore, it is crucial to implement a robust control system to regulate the process temperature and tackle the shortage of incoming solar energy during cloudy weather. In our previous works, different model–based control strategies were developed namely a Proportional Integral Derivative controller (PID) with gain scheduling and adaptive Model Predictive Control (MPC). These methods were tested numerically to regulate the temperature inside a high temperature tubular solar reactor. In this work, the proposed control strategies were experimentally tested under various operation conditions. The controllers were challenged to track different setpoints (500oC, 1000oC, and 1450oC) with different amounts of gas/particles flowrates. Additionally, the flow controller was tested to regulate the reactor temperature under a cloudy weather scenario. The ultimate goal was to produced 5 kg of reduced solar fuel magnesium manganese oxide (MgMn2O4) successfully, and the controllers were able to track the required process temperature and reject disturbances despite the system's strong nonlinearity. The experimental results showed a maximum error in the temperature setpoint of less than 0.5% (6°C), and the MPC controller demonstrated superior performance in reducing the control effort and rejecting disturbances.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42596787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a detailed analysis of the optical performance of circular trough concentrators with tubular receivers. First, a simple analytical formula for the achievable geometric concentration ratio as a function of the rim angle and acceptance angle is developed. Notably, the development reveals the existence of three distinct concentration ratio regimes: a first regime where the receiver is sized based on reflection of the edge rays from the rim alone; a second regime where the receiver is sized based on the rim and the edge ray caustics; and a third regime where two reflections from the mirror are permitted. Several exemplary designs are proposed and further analyzed using Monte Carlo ray tracing to obtain transmission angle curves and receiver flux distributions. For an acceptance angle of 1°, the circular trough concentrator with circular receiver is found to achieve a maximum geometric concentration ratio of 7.695× with a peak flux of 30 suns. For large acceptance angles (10°), the circular trough achieves a geometric concentration ratio as high as 82% of that of a parabolic trough. This noteworthy performance, together with the fact that a circular mirror is amenable to an inflated polymer construction, make this configuration promising for low-cost, low-concentration solar thermal applications.
{"title":"Nonimaging behavior of circular trough concentrators with tubular receivers","authors":"Matteo Timpano, T. Cooper","doi":"10.1115/1.4062482","DOIUrl":"https://doi.org/10.1115/1.4062482","url":null,"abstract":"\u0000 This paper presents a detailed analysis of the optical performance of circular trough concentrators with tubular receivers. First, a simple analytical formula for the achievable geometric concentration ratio as a function of the rim angle and acceptance angle is developed. Notably, the development reveals the existence of three distinct concentration ratio regimes: a first regime where the receiver is sized based on reflection of the edge rays from the rim alone; a second regime where the receiver is sized based on the rim and the edge ray caustics; and a third regime where two reflections from the mirror are permitted. Several exemplary designs are proposed and further analyzed using Monte Carlo ray tracing to obtain transmission angle curves and receiver flux distributions. For an acceptance angle of 1°, the circular trough concentrator with circular receiver is found to achieve a maximum geometric concentration ratio of 7.695× with a peak flux of 30 suns. For large acceptance angles (10°), the circular trough achieves a geometric concentration ratio as high as 82% of that of a parabolic trough. This noteworthy performance, together with the fact that a circular mirror is amenable to an inflated polymer construction, make this configuration promising for low-cost, low-concentration solar thermal applications.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42335638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Awad, S. Sherif, Heba Allah E.E. Khalil, A. Khalil, Tom I-P. Shih, Omar Abdelaziz, T. Abdel-Salam, Ryoichi S. Amano, Ashwani K. Gupta, Michael Brooks, B. Khandelwal, Nesrin Ozalp, David Carrington, S. Aggarwal, Dr. Sumanta Acharya, F. Mashayek, Xiuling Wang, W. E. Lear
This is a tribute to the late Professor Essam E. Khalil to honor his life and career achievements as Professor of Mechanical Power Engineering at Cairo University.
这是对已故的Essam E. Khalil教授的致敬，以表彰他作为开罗大学机械动力工程教授的生活和事业成就。
{"title":"In Memoriam: Professor Essam E. Khalil - A Tribute to an Outstanding Educator and Researcher","authors":"M. Awad, S. Sherif, Heba Allah E.E. Khalil, A. Khalil, Tom I-P. Shih, Omar Abdelaziz, T. Abdel-Salam, Ryoichi S. Amano, Ashwani K. Gupta, Michael Brooks, B. Khandelwal, Nesrin Ozalp, David Carrington, S. Aggarwal, Dr. Sumanta Acharya, F. Mashayek, Xiuling Wang, W. E. Lear","doi":"10.1115/1.4062476","DOIUrl":"https://doi.org/10.1115/1.4062476","url":null,"abstract":"\u0000 This is a tribute to the late Professor Essam E. Khalil to honor his life and career achievements as Professor of Mechanical Power Engineering at Cairo University.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44118792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, experimental works were carried out in three different drying methods named HE-ETADS, greenhouse solar dryer (GHSD), and open sun drying (OSD) to compare thin layer drying kinetics, concept of mass transfer, and quality assessment of banana slices. Initial moisture content (MC) of banana slices was obtained 78 ± 2.0% (wb), which decreased to 23.2 ± 2.0% (wb), 25.6 ± 2.0% (wb), and 28.8 ± 2.0 % (wb) in all three drying systems respectively in 9hours of drying time. Average drying rate was evaluated as 7.89, 7.65, and 7.25gwater/g solid.hr in HE-ETADS, GHSD, and OSD, respectively. Weibull model (WM) defines thin layer drying kinetics of banana slices in all three drying processes. Maximum hardness and shrinkage factor of dried banana slices were obtained as 373.6g and 75%, respectively, in HE-ETADS. Effective moisture diffusivity, activation energy, and mass transfer coefficient were computed as 1.11E-07 to 2.48E-07m2s−1, 30.25kJ/mole, 3.21E-04 to 1.0E-04m/s, in HE-ETADS. Similarly, in GHSD and OSD these factors were observed as 1.21E-07 to 2.34E-07m2s−1, 41.25kJ/mole, 3.15E-04 to1.0E-04 m/s and 1.3E-07 to 2.21E-07m2s−1, 56.89kJ/mole, 3.01E-04 to1.0E-04m/s. Maximum total color changes were noted in OSD. Hence, HE-ETADS can potentially dry high moisture content crops effectively within a minimum drying period.
{"title":"Heat and Mass Transfer, Quality, Performance Analysis, and Modeling of Thin Layer Drying Kinetics of Banana Slices","authors":"Anand Kushwah, Ashok Kumar, M. Gaur, A. Pal","doi":"10.1115/1.4062447","DOIUrl":"https://doi.org/10.1115/1.4062447","url":null,"abstract":"\u0000 In this study, experimental works were carried out in three different drying methods named HE-ETADS, greenhouse solar dryer (GHSD), and open sun drying (OSD) to compare thin layer drying kinetics, concept of mass transfer, and quality assessment of banana slices. Initial moisture content (MC) of banana slices was obtained 78 ± 2.0% (wb), which decreased to 23.2 ± 2.0% (wb), 25.6 ± 2.0% (wb), and 28.8 ± 2.0 % (wb) in all three drying systems respectively in 9hours of drying time. Average drying rate was evaluated as 7.89, 7.65, and 7.25gwater/g solid.hr in HE-ETADS, GHSD, and OSD, respectively. Weibull model (WM) defines thin layer drying kinetics of banana slices in all three drying processes. Maximum hardness and shrinkage factor of dried banana slices were obtained as 373.6g and 75%, respectively, in HE-ETADS. Effective moisture diffusivity, activation energy, and mass transfer coefficient were computed as 1.11E-07 to 2.48E-07m2s−1, 30.25kJ/mole, 3.21E-04 to 1.0E-04m/s, in HE-ETADS. Similarly, in GHSD and OSD these factors were observed as 1.21E-07 to 2.34E-07m2s−1, 41.25kJ/mole, 3.15E-04 to1.0E-04 m/s and 1.3E-07 to 2.21E-07m2s−1, 56.89kJ/mole, 3.01E-04 to1.0E-04m/s. Maximum total color changes were noted in OSD. Hence, HE-ETADS can potentially dry high moisture content crops effectively within a minimum drying period.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45679843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Solar energy desalination process is the most efficient and cost-effective method for producing fresh water from saline water by employing solar energy from the sun's free source of heat. In the current study, experimental and theoretical methods were used to investigate the performance of a novel design of conical solar still integrated with conical glass cover and conical basin area with continuous volume flow rate at different values of volume flow rate, 80, 60, and 40 mL/sec compared to traditional solar still. Experimental results showed that maximum productivity and efficiency can be achieved by utilizing the conical solar still at lower volume flow rate of saline water. Highest efficiency can be obtained by utilizing traditional single solar still (TSS), conical solar still with volume flow rate of 80 mL/sec (CSSF), conical solar still with volume flow rate of 60 mL/sec (CSSH), conical solar still with volume flow rate of 40 mL/sec (CSQ), and conical solar still with volume flow rate of 40 mL/sec with an array of the mirror (CSQM) on average is 28.2, 42.04, 53.78, 63.4, and 69.15 %, respectively. Freshwater productivity of CSQ was enhanced by employing the arrays of the mirror. Daily freshwater productivity of CSSF, CSSH, CSQ, and CSQM was enhanced on average by 221.5%, 160.4%, 157%, and 174.7%, respectively, over the freshwater productivity of TSS. Theoretical model is obtained utilizing Mathcad software and is validated by comparing it with experimental findings. The theoretical results obtained from the mathematical model are in good agreement with the experimental results.
{"title":"Performance of Modified Conical Solar Still Integrated with Continuous Volume Flow Rate","authors":"S. Abdallah, Safa M. Aldarabseh","doi":"10.1115/1.4062448","DOIUrl":"https://doi.org/10.1115/1.4062448","url":null,"abstract":"\u0000 Solar energy desalination process is the most efficient and cost-effective method for producing fresh water from saline water by employing solar energy from the sun's free source of heat. In the current study, experimental and theoretical methods were used to investigate the performance of a novel design of conical solar still integrated with conical glass cover and conical basin area with continuous volume flow rate at different values of volume flow rate, 80, 60, and 40 mL/sec compared to traditional solar still. Experimental results showed that maximum productivity and efficiency can be achieved by utilizing the conical solar still at lower volume flow rate of saline water. Highest efficiency can be obtained by utilizing traditional single solar still (TSS), conical solar still with volume flow rate of 80 mL/sec (CSSF), conical solar still with volume flow rate of 60 mL/sec (CSSH), conical solar still with volume flow rate of 40 mL/sec (CSQ), and conical solar still with volume flow rate of 40 mL/sec with an array of the mirror (CSQM) on average is 28.2, 42.04, 53.78, 63.4, and 69.15 %, respectively. Freshwater productivity of CSQ was enhanced by employing the arrays of the mirror. Daily freshwater productivity of CSSF, CSSH, CSQ, and CSQM was enhanced on average by 221.5%, 160.4%, 157%, and 174.7%, respectively, over the freshwater productivity of TSS. Theoretical model is obtained utilizing Mathcad software and is validated by comparing it with experimental findings. The theoretical results obtained from the mathematical model are in good agreement with the experimental results.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44944091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Heat collection performance simulations using the System Advisor Model (SAM) with Typical Meteorological Year weather data from four geographic locations are used to investigate (a) the optimum overall tilt of Piecewise-Focusing (PWF) collectors, and (b) PWF collector performance in comparison to the SAM default central receiver system. Results show that the overall tilt angle is not critical, but values up to 50 degrees are best at non-tropical latitudes, even when output in summer is more valuable than in winter. For tropical latitudes, 40 degrees of tilt is sufficient. Increasing PWF collector width relative to height is advantageous. Depending on location, PWF collector performance is 66% to 90% better than for the SAM default 100 MWe central receiver system, per m2 of reflector or heliostat. Using SAM's detailed control over system parameters, it is shown that the PWF collector's superior performance is derived mainly from better geometry (smaller cosine losses), but the near-absence of atmospheric attenuation and the smaller receiver heat losses are also significant.
{"title":"Optimization of Piecewise-Focusing CST collectors using the System Advisor Model, and comparison to a central receiver system","authors":"D. Bisset","doi":"10.1115/1.4062446","DOIUrl":"https://doi.org/10.1115/1.4062446","url":null,"abstract":"\u0000 Heat collection performance simulations using the System Advisor Model (SAM) with Typical Meteorological Year weather data from four geographic locations are used to investigate (a) the optimum overall tilt of Piecewise-Focusing (PWF) collectors, and (b) PWF collector performance in comparison to the SAM default central receiver system. Results show that the overall tilt angle is not critical, but values up to 50 degrees are best at non-tropical latitudes, even when output in summer is more valuable than in winter. For tropical latitudes, 40 degrees of tilt is sufficient. Increasing PWF collector width relative to height is advantageous. Depending on location, PWF collector performance is 66% to 90% better than for the SAM default 100 MWe central receiver system, per m2 of reflector or heliostat. Using SAM's detailed control over system parameters, it is shown that the PWF collector's superior performance is derived mainly from better geometry (smaller cosine losses), but the near-absence of atmospheric attenuation and the smaller receiver heat losses are also significant.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47142173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents an investigation of the performance indices employed in combined or multigeneration thermal systems. Specifically, the following thermal systems will be considered: (1) combined cooling and power (CCP) systems; (2) combined heating and power (CHP) systems; and (3) combined cooling, heating, and power (CCHP) systems. The investigation will highlight the main problems and limitations related to using these indices. We will propose a new procedure for evaluating the performance of CCP systems that can be generalized for use in other combined or multigeneration systems. Employing the subsystems forming any multigeneration system as a reference, the relative saving ratios of energy and exergy are calculated. These saving ratios are used as metrics for the goodness of multigeneration systems. We will also use them to calculate equivalent energetic and exergetic efficiencies of multigeneration systems. These equivalent efficiencies will be used as performance indicators of a multigeneration system as if it were producing only one of its products. The new procedure will be applied to three case studies in this paper. Results of this work indicate that the equivalent exergetic efficiency of power generation is the most meaningful and accurate performance index for assessing the performance of multigeneration systems.
{"title":"Guidance on Evaluating the Performance of Multigeneration Systems Based on Energetic and Exergetic Criteria","authors":"Abdulmajeed Alghamdi, S. Sherif","doi":"10.1115/1.4062376","DOIUrl":"https://doi.org/10.1115/1.4062376","url":null,"abstract":"\u0000 This paper presents an investigation of the performance indices employed in combined or multigeneration thermal systems. Specifically, the following thermal systems will be considered: (1) combined cooling and power (CCP) systems; (2) combined heating and power (CHP) systems; and (3) combined cooling, heating, and power (CCHP) systems. The investigation will highlight the main problems and limitations related to using these indices. We will propose a new procedure for evaluating the performance of CCP systems that can be generalized for use in other combined or multigeneration systems. Employing the subsystems forming any multigeneration system as a reference, the relative saving ratios of energy and exergy are calculated. These saving ratios are used as metrics for the goodness of multigeneration systems. We will also use them to calculate equivalent energetic and exergetic efficiencies of multigeneration systems. These equivalent efficiencies will be used as performance indicators of a multigeneration system as if it were producing only one of its products. The new procedure will be applied to three case studies in this paper. Results of this work indicate that the equivalent exergetic efficiency of power generation is the most meaningful and accurate performance index for assessing the performance of multigeneration systems.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43807025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The expected annual energy output of vertical bifacial solar panel arrays was modelled with an eye on how array design attributes affect the output. We considered module height, cell density (single- or double-high racking), inter-row spacing, and inverter connection (rows of modules wired together or separately), and the inclusion of bypass diodes. We observed that these design choices have a substantial impact on the annual energy yield on a per-module basis and per-acre basis. We modeled the instantaneous brightness and shading based on the position of the sun and adjacent rows of modules, which caused non-uniform irradiance due to inter-row shading effects. Based on the irradiance, we calculated current, voltage, and power values throughout a year for different design strategies. Double-high racking, which uses two landscape-oriented modules stacked vertically, offers noteworthy power gains per acre with only a modest increase of inter-row shading. When bypass diodes are included in the module design and improved inverter wiring is used, much of the loss due to inter-row shading is mitigated, and the total power output per acre is nearly doubled, with modules seeing an 80% power increase per acre for 20 ft row spacing, and over 90% power increase per acre for 40 ft spacing).
{"title":"Design Considerations for Vertical Bifacial Agrivoltaic Installations","authors":"","doi":"10.1115/1.4062323","DOIUrl":"https://doi.org/10.1115/1.4062323","url":null,"abstract":"\u0000 The expected annual energy output of vertical bifacial solar panel arrays was modelled with an eye on how array design attributes affect the output. We considered module height, cell density (single- or double-high racking), inter-row spacing, and inverter connection (rows of modules wired together or separately), and the inclusion of bypass diodes. We observed that these design choices have a substantial impact on the annual energy yield on a per-module basis and per-acre basis. We modeled the instantaneous brightness and shading based on the position of the sun and adjacent rows of modules, which caused non-uniform irradiance due to inter-row shading effects. Based on the irradiance, we calculated current, voltage, and power values throughout a year for different design strategies. Double-high racking, which uses two landscape-oriented modules stacked vertically, offers noteworthy power gains per acre with only a modest increase of inter-row shading. When bypass diodes are included in the module design and improved inverter wiring is used, much of the loss due to inter-row shading is mitigated, and the total power output per acre is nearly doubled, with modules seeing an 80% power increase per acre for 20 ft row spacing, and over 90% power increase per acre for 40 ft spacing).","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43496050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
By changing its design and materials, a solar dryer can help to lower consumption and drying time. The dryer was run with a reflector attached zigzag solar air heater thermally coated with 2% MWCNT, 2% CuO, and 96% black paint with a reflector. To check the microstructure and morphology analysis of the nano powders and coated surface XRD, SEM, EDAX and Elemental mapping has also been conducted. In this paper the feasibility of the cabinet dryer with rotating trays was investigated to dry ginger slices in case of attaching a energy storage device. The moisture content of the ginger slices were successfully reduced from 90 – 12% within the time frame of 7 hr 15 min. The different drying characteristics and quality parameters were evaluated and then compared in case of zigzag with coated surface and reflector, with coated surface and with reflector respectively. The results show that using a reflector it increases the air heater's outlet temperature by 10-12%, and using a coated surface increases the temperature by another 8–10%. The average thermal and exergy efficiency of an air heater was found to be 70.2 and 4.4 %, respectively. The average overall thermal efficiency of carbon nanotubes + copper oxide-paraffin wax energy storage unit was 31.19%, with 11.9 % as the average overall exergy efficiency. The energy storage increases the drying time near about 3 hr during off sunshine hours.
{"title":"Investigation on Solar Drying Characteristics of Ginger (Zingiber officinale) in a Reflector Attached Solar Air Heater and Thermal Energy Storage System using Nano Materials","authors":"C. Sethi, S. Acharya, P. Patnaik","doi":"10.1115/1.4062195","DOIUrl":"https://doi.org/10.1115/1.4062195","url":null,"abstract":"\u0000 By changing its design and materials, a solar dryer can help to lower consumption and drying time. The dryer was run with a reflector attached zigzag solar air heater thermally coated with 2% MWCNT, 2% CuO, and 96% black paint with a reflector. To check the microstructure and morphology analysis of the nano powders and coated surface XRD, SEM, EDAX and Elemental mapping has also been conducted. In this paper the feasibility of the cabinet dryer with rotating trays was investigated to dry ginger slices in case of attaching a energy storage device. The moisture content of the ginger slices were successfully reduced from 90 – 12% within the time frame of 7 hr 15 min. The different drying characteristics and quality parameters were evaluated and then compared in case of zigzag with coated surface and reflector, with coated surface and with reflector respectively. The results show that using a reflector it increases the air heater's outlet temperature by 10-12%, and using a coated surface increases the temperature by another 8–10%. The average thermal and exergy efficiency of an air heater was found to be 70.2 and 4.4 %, respectively. The average overall thermal efficiency of carbon nanotubes + copper oxide-paraffin wax energy storage unit was 31.19%, with 11.9 % as the average overall exergy efficiency. The energy storage increases the drying time near about 3 hr during off sunshine hours.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":"60 34","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41308819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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