Melissa Messenger, Casey J. Troxler, Isabel Melendez, Thomas B Freeman, Nicholas Reed, Rafael Rodríguez, S. Boetcher
Phase-change materials (PCMs) can be used to develop thermal energy storage systems as they absorb large amount of latent heat at nearly a constant temperature when changing phase from solid to a liquid. To prevent leakage when in a liquid state, PCM is shape stabilized in a polymer matrix of high-density polyethylene (HDPE). The present research explores the injection-molded mechanical and thermal properties of different PCM/HDPE composite ratios to serve as a comparable foundation for PCM/HDPE composites that are 3D printed using fused filament fabrication (FFF). The tensile strength and modulus of elasticity at room temperature and with the PCM fully melted within the composite are measured. Additionally, the hardness, latent heat of fusion, phase-change temperature, and thermal conductivity are investigated. An analysis of microstructures of the composite is used to support the findings. The PCM within the PCM/HDPE composite gives it the benefit of thermal storage but causes a decrease in mechanical properties.
{"title":"Mechanical and thermal characterization of phase change material and high-density polyethylene functional composites for thermal energy storage","authors":"Melissa Messenger, Casey J. Troxler, Isabel Melendez, Thomas B Freeman, Nicholas Reed, Rafael Rodríguez, S. Boetcher","doi":"10.1115/1.4062197","DOIUrl":"https://doi.org/10.1115/1.4062197","url":null,"abstract":"\u0000 Phase-change materials (PCMs) can be used to develop thermal energy storage systems as they absorb large amount of latent heat at nearly a constant temperature when changing phase from solid to a liquid. To prevent leakage when in a liquid state, PCM is shape stabilized in a polymer matrix of high-density polyethylene (HDPE). The present research explores the injection-molded mechanical and thermal properties of different PCM/HDPE composite ratios to serve as a comparable foundation for PCM/HDPE composites that are 3D printed using fused filament fabrication (FFF). The tensile strength and modulus of elasticity at room temperature and with the PCM fully melted within the composite are measured. Additionally, the hardness, latent heat of fusion, phase-change temperature, and thermal conductivity are investigated. An analysis of microstructures of the composite is used to support the findings. The PCM within the PCM/HDPE composite gives it the benefit of thermal storage but causes a decrease in mechanical properties.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48761890","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}
Y. Aider, I. Kaur, Ashreet Mishra, Like Li, Heejin Cho, Janna Martinek, Zhiwen Ma, Prashant Singh
Particle-to-supercritical carbon dioxide (sCO2) heat exchanger is a critical component in next-generation concentrating solar power (CSP) plants. The inherently low heat transfer between falling particles and sCO2 imposes a challenge towards economic justification of levelized cost of electricity produced through solar energy. Introduction of integrated porous media with the walls bounding particle flow has the potential to enhance the overall particle-to-sCO2 heat exchanger performance. This paper presents an experimental study on heat transfer characterization of additively manufactured lattice frame material based on Octet-shaped unit cell with particles and air as working fluids. The lattice structures were additively manufactured in Stainless Steel (SS) 316L and SS420 (with 40% bronze infiltration) via Binder jetting process, where the lattice porosities were varied between 0.75 and 0.9. The mean particle diameters were varied from 266-966 μm. The effective thermal conductivity and averaged heat transfer coefficient were determined through steady-state experiments. It was found that the presence of lattice enhances the effective thermal conductivity by 2-4 times when compared to packed bed of particles alone. Furthermore, for gravity-assisted particle flow through lattice panel, significantly high convective heat transfer coefficients ranging from 200-400 W/m2K were obtained for the range of particle diameters tested. The superior thermal transport properties of Octet-shape-based lattice frame for particle flow makes it a very promising candidate for particle-to-sCO2 heat exchanger for CSP application.
{"title":"Heat Transfer Characteristics of Particle and Air Flow Through Additively Manufactured Lattice Frame Material Based on Octet-Shape Topology","authors":"Y. Aider, I. Kaur, Ashreet Mishra, Like Li, Heejin Cho, Janna Martinek, Zhiwen Ma, Prashant Singh","doi":"10.1115/1.4062196","DOIUrl":"https://doi.org/10.1115/1.4062196","url":null,"abstract":"\u0000 Particle-to-supercritical carbon dioxide (sCO2) heat exchanger is a critical component in next-generation concentrating solar power (CSP) plants. The inherently low heat transfer between falling particles and sCO2 imposes a challenge towards economic justification of levelized cost of electricity produced through solar energy. Introduction of integrated porous media with the walls bounding particle flow has the potential to enhance the overall particle-to-sCO2 heat exchanger performance. This paper presents an experimental study on heat transfer characterization of additively manufactured lattice frame material based on Octet-shaped unit cell with particles and air as working fluids. The lattice structures were additively manufactured in Stainless Steel (SS) 316L and SS420 (with 40% bronze infiltration) via Binder jetting process, where the lattice porosities were varied between 0.75 and 0.9. The mean particle diameters were varied from 266-966 μm. The effective thermal conductivity and averaged heat transfer coefficient were determined through steady-state experiments. It was found that the presence of lattice enhances the effective thermal conductivity by 2-4 times when compared to packed bed of particles alone. Furthermore, for gravity-assisted particle flow through lattice panel, significantly high convective heat transfer coefficients ranging from 200-400 W/m2K were obtained for the range of particle diameters tested. The superior thermal transport properties of Octet-shape-based lattice frame for particle flow makes it a very promising candidate for particle-to-sCO2 heat exchanger for CSP application.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44803757","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 opaque photovoltaic thermal (PVT) produces both thermal and electrical energy. In order to increase thermal energy, we have considered flexible (Al based) PV module for the present study. Further, we have considered thermo-electric cooler (TEC) integrated with flexible PV module to enhanced electrical power. Hence, an overall power can be increases in flexible PVT-TEC collector. A concept of series and parallel combination of flexible PVT-TEC collectors is proposed to optimize of series (n) and parallel (m) combinations for a given number of N (= n × m) collectors for maximum overall exergy depending on thermal and electrical energy which has not been considered yet so far. Further, a new expression has also been developed for the heat removal factor and instantaneous thermal efficiency of nth flexible PVT-TEC collector to investigate its effect on the nth flexible PVT-TEC collector performance. Numerical computations have been carried out for a given coldest climatic condition of Srinagar, India and design parameters of Al-based PVT-TEC collectors using MATLAB R2021b. Based on numerical computations, following conclusions have been drawn: For case (a) (all flexible PVT-TEC collectors are connected in parallel), the daily overall exergy is 2.7 kW which is 21.3% more than case (d) (All flexible PVT-TEC collectors are connected in series).There is a drop of 20% in mass flow rate factor due to correction factor.
{"title":"Study of performance of the flexible (Al-based) N-PVT-TEC collectors in different configurations","authors":"G. Tiwari, Rohit Singh, A. Sinha, A. Singh","doi":"10.1115/1.4062171","DOIUrl":"https://doi.org/10.1115/1.4062171","url":null,"abstract":"The opaque photovoltaic thermal (PVT) produces both thermal and electrical energy. In order to increase thermal energy, we have considered flexible (Al based) PV module for the present study. Further, we have considered thermo-electric cooler (TEC) integrated with flexible PV module to enhanced electrical power. Hence, an overall power can be increases in flexible PVT-TEC collector. A concept of series and parallel combination of flexible PVT-TEC collectors is proposed to optimize of series (n) and parallel (m) combinations for a given number of N (= n × m) collectors for maximum overall exergy depending on thermal and electrical energy which has not been considered yet so far. Further, a new expression has also been developed for the heat removal factor and instantaneous thermal efficiency of nth flexible PVT-TEC collector to investigate its effect on the nth flexible PVT-TEC collector performance. Numerical computations have been carried out for a given coldest climatic condition of Srinagar, India and design parameters of Al-based PVT-TEC collectors using MATLAB R2021b. Based on numerical computations, following conclusions have been drawn: For case (a) (all flexible PVT-TEC collectors are connected in parallel), the daily overall exergy is 2.7 kW which is 21.3% more than case (d) (All flexible PVT-TEC collectors are connected in series).There is a drop of 20% in mass flow rate factor due to correction factor.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45384775","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}
Ridha Benadli, D. Frey, Y. Lembeye, Marwen Bjaoui, B. Khiari, A. Sellami
In this paper, we introduce a novel direct maximum power point tracking (MPPT) approach that combines the backstepping controller (BC) and the super-twisting algorithm (STA). The direct backstepping super-twisting algorithm control (BSSTAC) MPPT was developed to extract the maximum power point (MPP) produced by a photovoltaic (PV) generator connected to the battery through a boost dc-dc converter. To reduce the number of sensors required for the BSSTAC implementation, a high gain observer (HGO) was proposed to estimate the value of the state of the PV storage system from measurements of the PV generator voltage and current. The suggested technique is based on the quadratic Lyapunov function and does not employ a standard MPPT algorithm. Results show that the suggested control scheme has good tracking performance with reduced overshoot, chattering, and settling time as compared to the prevalent MPPT tracking algorithms such as perturb and observe (P&O), conventional sliding mode control (CSMC), backstepping controller (BSC), and integral backstepping controller (IBSC). Finally, real-time findings using the dSPACE DS 1104 software indicate that the generator PV can accurately forecast the MPP, as well as the efficacy of the suggested MPPT technique. The provided approach's effectiveness has been validated by a comprehensive comparison with different methods, resulting in the greatest efficiency of 99.88% for BSSTAC.
{"title":"A direct backstepping super-twisting algorithm controller MPPT for a standalone PV storage system: design and real-time implementation","authors":"Ridha Benadli, D. Frey, Y. Lembeye, Marwen Bjaoui, B. Khiari, A. Sellami","doi":"10.1115/1.4062096","DOIUrl":"https://doi.org/10.1115/1.4062096","url":null,"abstract":"\u0000 In this paper, we introduce a novel direct maximum power point tracking (MPPT) approach that combines the backstepping controller (BC) and the super-twisting algorithm (STA). The direct backstepping super-twisting algorithm control (BSSTAC) MPPT was developed to extract the maximum power point (MPP) produced by a photovoltaic (PV) generator connected to the battery through a boost dc-dc converter. To reduce the number of sensors required for the BSSTAC implementation, a high gain observer (HGO) was proposed to estimate the value of the state of the PV storage system from measurements of the PV generator voltage and current. The suggested technique is based on the quadratic Lyapunov function and does not employ a standard MPPT algorithm. Results show that the suggested control scheme has good tracking performance with reduced overshoot, chattering, and settling time as compared to the prevalent MPPT tracking algorithms such as perturb and observe (P&O), conventional sliding mode control (CSMC), backstepping controller (BSC), and integral backstepping controller (IBSC). Finally, real-time findings using the dSPACE DS 1104 software indicate that the generator PV can accurately forecast the MPP, as well as the efficacy of the suggested MPPT technique. The provided approach's effectiveness has been validated by a comprehensive comparison with different methods, resulting in the greatest efficiency of 99.88% for BSSTAC.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44684028","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}
N. Jilani, S. Yadav, S. K. Panda, P. Mohapatra, G. Tiwari
The present study proposes a Quonset-type greenhouse integrated with a thin-film photovoltaic thermal (GiPVT) system for crop cultivation in harsh hot climate conditions. A periodic thermal model in terms of input climatic and design parameters has been developed to evaluate the GiPVT system's thermal performance. This model is based on the energy balance equations of the GiPVT system, and it calculates PV roof temperature, greenhouse air temperature, and plant temperature for a given climatic data, i.e., solar irradiation and ambient air temperature. Furthermore, the thermal load leveling for the GiPVT system is determined to assess the thermal comfort status within the enclosed space of the system. The results indicate that EAHE successfully reduces greenhouse air temperature and increases the thermal comfort level inside the GiPVT system. Corresponding to the optimum flow rate of 0.5 kg/s, the maximum temperature of the plants and greenhouse is reduced by 20 °C and 21 °C, respectively. Moreover, the present GiPVT system produces 29.22 kWh of electrical energy per day, making the system self-sustainable.
{"title":"Performance of Quonset type Greenhouse integrated with thin film Photovoltaic Thermal system combined with Earth Air Heat Exchanger for hot and dry climatic conditions.","authors":"N. Jilani, S. Yadav, S. K. Panda, P. Mohapatra, G. Tiwari","doi":"10.1115/1.4062097","DOIUrl":"https://doi.org/10.1115/1.4062097","url":null,"abstract":"\u0000 The present study proposes a Quonset-type greenhouse integrated with a thin-film photovoltaic thermal (GiPVT) system for crop cultivation in harsh hot climate conditions. A periodic thermal model in terms of input climatic and design parameters has been developed to evaluate the GiPVT system's thermal performance. This model is based on the energy balance equations of the GiPVT system, and it calculates PV roof temperature, greenhouse air temperature, and plant temperature for a given climatic data, i.e., solar irradiation and ambient air temperature. Furthermore, the thermal load leveling for the GiPVT system is determined to assess the thermal comfort status within the enclosed space of the system. The results indicate that EAHE successfully reduces greenhouse air temperature and increases the thermal comfort level inside the GiPVT system. Corresponding to the optimum flow rate of 0.5 kg/s, the maximum temperature of the plants and greenhouse is reduced by 20 °C and 21 °C, respectively. Moreover, the present GiPVT system produces 29.22 kWh of electrical energy per day, making the system self-sustainable.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46585361","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 integration of Solar-powered pumping systems (SPPS) into agriculture and wastewater sectors becomes mandatory to provide water in remote regions. The broad use of SPPS with classical maximum power point tracking controllers (MPPTCs) showed moderated voltage and power response deterioration. This paper presents a new simple, cost-effective real-time hardware-in-the-loop (RT-HIL) framework to enhance the dynamic performance of SPPS. To accomplish this study, a real pumping station was modeled and equipped with MPPTCs through MATLAB/SIMULINK. Besides, a practical SPPS was implemented to evaluate the effectiveness of the proposed RT-HIL on system performance. The tuned PI/FOPI-based MPPTCs are adopted in this work to gain the maximum power from the PV generator under measured real environmental conditions. The proposed real-time MPPTCs techniques are Perturb and Observe and Incremental Conductance with I, PI, and fractional-order PI (FOPI) controllers. The simulation and the experimental results prove the superiority of the developed real-time FOPI-based MPPTCs on enhancing the system performance in terms of the gained power, module output current, pump flow rate, and pump efficiency. Paper's novelty lies behind the relatively low-cost real-time execution of PI/FOPI based MPPT techniques on SPPS. This work was simulated using MATLAB/SIMULINK in conjunction with Arduino-based RT-HIL and the experimental validation was implemented at the National Water Research Center (NWRC) in Egypt.
{"title":"Real-time dynamic performance enhancement for solar-powered pumping systems using PI-based MPPT techniques","authors":"M. Ebrahim, Adham Osama, K. Fetyan","doi":"10.1115/1.4057038","DOIUrl":"https://doi.org/10.1115/1.4057038","url":null,"abstract":"\u0000 The integration of Solar-powered pumping systems (SPPS) into agriculture and wastewater sectors becomes mandatory to provide water in remote regions. The broad use of SPPS with classical maximum power point tracking controllers (MPPTCs) showed moderated voltage and power response deterioration. This paper presents a new simple, cost-effective real-time hardware-in-the-loop (RT-HIL) framework to enhance the dynamic performance of SPPS. To accomplish this study, a real pumping station was modeled and equipped with MPPTCs through MATLAB/SIMULINK. Besides, a practical SPPS was implemented to evaluate the effectiveness of the proposed RT-HIL on system performance. The tuned PI/FOPI-based MPPTCs are adopted in this work to gain the maximum power from the PV generator under measured real environmental conditions. The proposed real-time MPPTCs techniques are Perturb and Observe and Incremental Conductance with I, PI, and fractional-order PI (FOPI) controllers. The simulation and the experimental results prove the superiority of the developed real-time FOPI-based MPPTCs on enhancing the system performance in terms of the gained power, module output current, pump flow rate, and pump efficiency. Paper's novelty lies behind the relatively low-cost real-time execution of PI/FOPI based MPPT techniques on SPPS. This work was simulated using MATLAB/SIMULINK in conjunction with Arduino-based RT-HIL and the experimental validation was implemented at the National Water Research Center (NWRC) in Egypt.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43475746","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}
Juri Sonowal, Mrinal Bhowmik, M. Palanisamy, R. Anandalakshmi
This study investigates the thermal performance of an evacuated U-tube solar collector (ETSC) using different tube geometrical configurations. The effect of tube geometry on overall collector efficiency is numerically analysed and compared with experimental results. Three different ETSC configurations made of copper viz., model 1 (M1) having one inlet and two outlets, model 2 (M2) having one inlet and three outlets, and model 3 (M3) having one inlet and four outlets are considered. An overall rise in temperature of heat transfer fluid at outlets for each model is predicted and compared with conventional U-tube (CT) for different mass flow rates and solar insolation to evaluate the collector performance. In comparison with the CT, the outlet temperature of the M3 and M1 is higher by 46.2 % and 40.3% respectively. M2 gives a nearly similar fluid outlet temperature as M1. A maximum of 35.4% enhancement in heat gain compared to the CT is observed for M3 (which is best among modified configurations) under similar operating conditions. However, at 788 W/m2 solar insolation and a constant mass flowrate of 0.0167 kg/s, the estimated thermal efficiency of M1 is higher among the three models which is 33.5% higher than the CT. The experimental results closely approximate the numerical predictions with a deviation of ±1.1°C . From the economic evaluation of the modified collectors, a minimum payback period of 2.5 years was observed for model 1 which is the shortest among the investigated ETSC systems.
{"title":"Comparative Study of Different Tube Geometries of Evacuated Tube Solar Collector","authors":"Juri Sonowal, Mrinal Bhowmik, M. Palanisamy, R. Anandalakshmi","doi":"10.1115/1.4056904","DOIUrl":"https://doi.org/10.1115/1.4056904","url":null,"abstract":"\u0000 This study investigates the thermal performance of an evacuated U-tube solar collector (ETSC) using different tube geometrical configurations. The effect of tube geometry on overall collector efficiency is numerically analysed and compared with experimental results. Three different ETSC configurations made of copper viz., model 1 (M1) having one inlet and two outlets, model 2 (M2) having one inlet and three outlets, and model 3 (M3) having one inlet and four outlets are considered. An overall rise in temperature of heat transfer fluid at outlets for each model is predicted and compared with conventional U-tube (CT) for different mass flow rates and solar insolation to evaluate the collector performance. In comparison with the CT, the outlet temperature of the M3 and M1 is higher by 46.2 % and 40.3% respectively. M2 gives a nearly similar fluid outlet temperature as M1. A maximum of 35.4% enhancement in heat gain compared to the CT is observed for M3 (which is best among modified configurations) under similar operating conditions. However, at 788 W/m2 solar insolation and a constant mass flowrate of 0.0167 kg/s, the estimated thermal efficiency of M1 is higher among the three models which is 33.5% higher than the CT. The experimental results closely approximate the numerical predictions with a deviation of ±1.1°C . From the economic evaluation of the modified collectors, a minimum payback period of 2.5 years was observed for model 1 which is the shortest among the investigated ETSC systems.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41526636","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 Compound Parabolic Concentrator (CPC), when coupled with the photovoltaic system, namely the Concentrated photovoltaic thermal system (CPVT), makes utilizing solar energy efficiently. The major challenge that hinders the electrical and thermal performance of the CPC-CPVT system is the non-uniform heat flux distribution on the absorber surface. In the present paper, detailed ray tracing simulations have been carried out to understand the heat flux distribution characteristics of CPC with different geometrical conditions are concentration ratio, truncation ratio, incident angle and average heat flux on the absorber surface. To have a thorough understanding, the analysis has been carried out in multiple steps. Firstly, by analysing the effect of concentration ratio and incident angle on heat flux distribution characteristics at a fixed truncation ratio. Secondly, investigations have been carried out to understand the heat flux distribution characteristics at different truncation ratios and different incident angles by keeping the concentration ratio constant. Local Concentration Ratio (LCR) and non-uniformity index have been employed to quantify the non-uniformity of heat flux distribution on the absorber surface. It has been observed that the 0° incidence angle is the most effective angle to achieve uniform heat flux distribution on the absorber surface. This paper sheds insight on the heat flux distribution characteristics on the absorber surface of a CPC-CPVT system which can be used by the research community for designing an effective CPVT system from the perspective of uniform heat flux distribution on the absorber surface.
{"title":"Evaluation of Heat Flux Distribution on Flat Plate Compound Parabolic Concentrator with Different Geometric Indices","authors":"Mathiyazhagan Shanmugam, Lakshmi Sirisha Maganti","doi":"10.1115/1.4056847","DOIUrl":"https://doi.org/10.1115/1.4056847","url":null,"abstract":"\u0000 The Compound Parabolic Concentrator (CPC), when coupled with the photovoltaic system, namely the Concentrated photovoltaic thermal system (CPVT), makes utilizing solar energy efficiently. The major challenge that hinders the electrical and thermal performance of the CPC-CPVT system is the non-uniform heat flux distribution on the absorber surface. In the present paper, detailed ray tracing simulations have been carried out to understand the heat flux distribution characteristics of CPC with different geometrical conditions are concentration ratio, truncation ratio, incident angle and average heat flux on the absorber surface. To have a thorough understanding, the analysis has been carried out in multiple steps. Firstly, by analysing the effect of concentration ratio and incident angle on heat flux distribution characteristics at a fixed truncation ratio. Secondly, investigations have been carried out to understand the heat flux distribution characteristics at different truncation ratios and different incident angles by keeping the concentration ratio constant. Local Concentration Ratio (LCR) and non-uniformity index have been employed to quantify the non-uniformity of heat flux distribution on the absorber surface. It has been observed that the 0° incidence angle is the most effective angle to achieve uniform heat flux distribution on the absorber surface. This paper sheds insight on the heat flux distribution characteristics on the absorber surface of a CPC-CPVT system which can be used by the research community for designing an effective CPVT system from the perspective of uniform heat flux distribution on the absorber surface.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42882908","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}
{"title":"Reviewer's Recognition","authors":"S. Sherif","doi":"10.1115/1.4056795","DOIUrl":"https://doi.org/10.1115/1.4056795","url":null,"abstract":"","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46708953","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}
Recently, many studies have reported that a curved solar air heater (CSAH) performs better than a conventional flat SAH without using any extra material. It only requires geometrical modification. The present investigation is a two-dimensional numerical study of flow, heat transfer and entropy generation characteristics of a CSAH having a sinusoidal profile absorber plate. Reynolds number (Re) and relative roughness pitch (λ/a) have been varied from 3800 to 18000 and 7.143 to 17.857, respectively, while keeping the value of relative roughness height (a/Dh) at 0.042. The finite volume method (FVM) and SST k-λ model have been used to solve the governing equations. The average Nusselt number and average friction factor have been calculated to find the thermo-hydraulic performance parameter (THPP), which further helped determine the optimal arrangement of the number of sinusoidal waves in the absorber plate of the SAH. The maximum value of THPP developed with the proposed setup was found to be 5.9778. Turbulent flow features have been represented in the form of contours. Correlations have also been developed for Nuavgr and favgr as a function of Re and λ/a. Entropy generation per unit length due to heat transfer and fluid friction has been graphically represented.
{"title":"Heat transfer and entropy generation analysis of a curved solar air heater with a sinusoidal absorber plate","authors":"Harsh Katoch, S. Rathore, Chinmaya Mund","doi":"10.1115/1.4056789","DOIUrl":"https://doi.org/10.1115/1.4056789","url":null,"abstract":"Recently, many studies have reported that a curved solar air heater (CSAH) performs better than a conventional flat SAH without using any extra material. It only requires geometrical modification. The present investigation is a two-dimensional numerical study of flow, heat transfer and entropy generation characteristics of a CSAH having a sinusoidal profile absorber plate. Reynolds number (Re) and relative roughness pitch (λ/a) have been varied from 3800 to 18000 and 7.143 to 17.857, respectively, while keeping the value of relative roughness height (a/Dh) at 0.042. The finite volume method (FVM) and SST k-λ model have been used to solve the governing equations. The average Nusselt number and average friction factor have been calculated to find the thermo-hydraulic performance parameter (THPP), which further helped determine the optimal arrangement of the number of sinusoidal waves in the absorber plate of the SAH. The maximum value of THPP developed with the proposed setup was found to be 5.9778. Turbulent flow features have been represented in the form of contours. Correlations have also been developed for Nuavgr and favgr as a function of Re and λ/a. Entropy generation per unit length due to heat transfer and fluid friction has been graphically represented.","PeriodicalId":17124,"journal":{"name":"Journal of Solar Energy Engineering-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46813260","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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