J. Fajardo, Hermes Ramírez-León, D. Barreto, Carlos Rico, Camilo Cardona
A Computer Room Air Conditioner (CRAC) system has been modeled and simulated to set up a Condition-based maintenance strategy oriented on the equipment’s energy efficiency performance (MCEE). The modeling was performed using ASPEN HYSYS based on actual performance conditions of a CRAC system in the Caribbean Colombia area. The condition-based was simulated based on a fouling model increase in the evaporator and condenser, decreasing the heat transfer process and increasing the heat loss. A 2-year fouling increase model was performed to obtain an economic-technical cost-function parameter and develop a cost-effective cleaning schedule for the evaporator and condenser. The results show a 5% COP decrease due to a fouling increase. The maintenance schedule for cleaning this system is cost-effective on the 310th day. Furthermore, a Critical Matrix of the CRAC performance is developed based on energy efficiency and a cost function.
{"title":"Energy Efficiency Condition-Based Maintenance Methodology for Computer Room Air Conditioners","authors":"J. Fajardo, Hermes Ramírez-León, D. Barreto, Carlos Rico, Camilo Cardona","doi":"10.1115/imece2022-91987","DOIUrl":"https://doi.org/10.1115/imece2022-91987","url":null,"abstract":"\u0000 A Computer Room Air Conditioner (CRAC) system has been modeled and simulated to set up a Condition-based maintenance strategy oriented on the equipment’s energy efficiency performance (MCEE). The modeling was performed using ASPEN HYSYS based on actual performance conditions of a CRAC system in the Caribbean Colombia area. The condition-based was simulated based on a fouling model increase in the evaporator and condenser, decreasing the heat transfer process and increasing the heat loss. A 2-year fouling increase model was performed to obtain an economic-technical cost-function parameter and develop a cost-effective cleaning schedule for the evaporator and condenser. The results show a 5% COP decrease due to a fouling increase. The maintenance schedule for cleaning this system is cost-effective on the 310th day. Furthermore, a Critical Matrix of the CRAC performance is developed based on energy efficiency and a cost function.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76011435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present study aims to evaluate the intrinsic differences in in-cylinder combustion in low load and low-speed conditions by applying experimental and numerical techniques. The experimental apparatus consisted of an AVL5406 SI-PFI single-cylinder with optical access operating under two different fuel delivery methods: Port Fuel Injection (PFI) and Direct fuel Injection (DI) with anhydrous ethanol (E100) and hydrous ethanol (E96W4). The outcomes of the engine-like conditions tests were evaluated based on the quantitative analysis of the flame propagation and on the thermodynamic data obtained using INDICOM. A Video Scope VS4-1845HS high-speed camera providing cycle resolved UV-visible digital image captured the natural emission of the flame for each test. Forthwith image acquisition, the flame propagation characteristics were post-processed through image segmentation techniques. Finally, relevant literature was revised to support the results and findings obtained at this time. The contribution of this study to the internal combustion engines research remains in gathering more information about in-cylinder flame front propagation and combustion stability for E96W4 and E100 ethanol under partial load and stoichiometric and lean conditions.
{"title":"Flame Propagation Analysis of Anhydrous and Hydrous Ethanol in an Optical Spark Ignition Engine","authors":"Fernanda Pinheiro-Martins, P. Teixeira Lacava","doi":"10.1115/imece2022-89116","DOIUrl":"https://doi.org/10.1115/imece2022-89116","url":null,"abstract":"\u0000 The present study aims to evaluate the intrinsic differences in in-cylinder combustion in low load and low-speed conditions by applying experimental and numerical techniques. The experimental apparatus consisted of an AVL5406 SI-PFI single-cylinder with optical access operating under two different fuel delivery methods: Port Fuel Injection (PFI) and Direct fuel Injection (DI) with anhydrous ethanol (E100) and hydrous ethanol (E96W4).\u0000 The outcomes of the engine-like conditions tests were evaluated based on the quantitative analysis of the flame propagation and on the thermodynamic data obtained using INDICOM. A Video Scope VS4-1845HS high-speed camera providing cycle resolved UV-visible digital image captured the natural emission of the flame for each test. Forthwith image acquisition, the flame propagation characteristics were post-processed through image segmentation techniques. Finally, relevant literature was revised to support the results and findings obtained at this time.\u0000 The contribution of this study to the internal combustion engines research remains in gathering more information about in-cylinder flame front propagation and combustion stability for E96W4 and E100 ethanol under partial load and stoichiometric and lean conditions.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74968321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Morgan Smith, Zachary Musgrove, Yuxin Song, Hao Hu, Shawn Duan
Great interest has been expressed in the harnessing of methane biogas from the decomposition of biowaste to combust in an electric generator to produce electricity. Biogas produced in this way is a mixture of methane gas, carbon dioxide, and hydrogen sulfide. To use this gas as a fuel for an electric generator, the gas mixture needs to be purified and dried to create a purer methane fuel in a process called upgrading. The application of such a technology has been posed as most effective in a situation where biowaste in the form of excrement, whether human or animal, is plentiful, and where conventional reliance on electric infrastructure is difficult. The Washington State Department of Transportation (WSDOT) has proposed one such application lies in the 47 safety rest areas possessed by the state. The goal of this project is to design and prototype a system which will take biowaste, in this case cow manure, and create a self-contained system which will collect and filter biogas to create methane fuel and supply this fuel to a generator modified to run on methane to produce electricity. This project successfully produced 8.5 pounds-per-square-inch of mixed biogas in an anaerobic digester and has created a filtration system to upgrade the gas for fuel in the electric generator. The mixed biogas is at a methane concentration of 100% of the lower-explosive-limit.
{"title":"Electrical Power Generation From Biogas Upgrading","authors":"Morgan Smith, Zachary Musgrove, Yuxin Song, Hao Hu, Shawn Duan","doi":"10.1115/imece2022-95280","DOIUrl":"https://doi.org/10.1115/imece2022-95280","url":null,"abstract":"\u0000 Great interest has been expressed in the harnessing of methane biogas from the decomposition of biowaste to combust in an electric generator to produce electricity. Biogas produced in this way is a mixture of methane gas, carbon dioxide, and hydrogen sulfide. To use this gas as a fuel for an electric generator, the gas mixture needs to be purified and dried to create a purer methane fuel in a process called upgrading. The application of such a technology has been posed as most effective in a situation where biowaste in the form of excrement, whether human or animal, is plentiful, and where conventional reliance on electric infrastructure is difficult. The Washington State Department of Transportation (WSDOT) has proposed one such application lies in the 47 safety rest areas possessed by the state. The goal of this project is to design and prototype a system which will take biowaste, in this case cow manure, and create a self-contained system which will collect and filter biogas to create methane fuel and supply this fuel to a generator modified to run on methane to produce electricity. This project successfully produced 8.5 pounds-per-square-inch of mixed biogas in an anaerobic digester and has created a filtration system to upgrade the gas for fuel in the electric generator. The mixed biogas is at a methane concentration of 100% of the lower-explosive-limit.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"7 18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75213845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The purpose of this research is to evaluate the feasibility and performance of a vertical ground source refrigeration system for cooling a typical 7300 m2 office building after replacing cooling towers used for condenser cooling with three different designs of ground heat exchangers. To that end, a three-dimensional, transient, and conjugated finite volume model is developed and simulated to compare the thermo-hydraulic performance of the traditional single U-tube with that of double U-shaped, and spiral-shaped ground heat exchangers at different flow rates. Based on the results, spiral shaped ground heat exchangers outperform other designs, as seen by better heat exchange rates between the fluid and the soil, which translates to a greater temperature reduction of the cooling water. This improvement not only allows for using smaller number of boreholes which saves the construction costs compared to other designs, but it also improves the coefficient of performance of the system by significantly lowering the cooling water temperature flowing back to the condenser when compared to the conventional cooling tower. This approach also eliminates cooling tower water consumption (saves about 14,500 L/day), tower noise, annual maintenance expenses, and costs for periodical cooling tower replacement. The presented findings make a significant contribution to society by offering innovative and sustainable solutions for cost reduction, environmental conservation, and energy efficiency.
{"title":"The Potential and Limitations of Using Geothermal-Sourced Chiller Plants to Eliminate Cooling Towers","authors":"A. Farag, Mahmoud A. Ahmed, S. Ookawara, M. Emam","doi":"10.1115/imece2022-96657","DOIUrl":"https://doi.org/10.1115/imece2022-96657","url":null,"abstract":"\u0000 The purpose of this research is to evaluate the feasibility and performance of a vertical ground source refrigeration system for cooling a typical 7300 m2 office building after replacing cooling towers used for condenser cooling with three different designs of ground heat exchangers. To that end, a three-dimensional, transient, and conjugated finite volume model is developed and simulated to compare the thermo-hydraulic performance of the traditional single U-tube with that of double U-shaped, and spiral-shaped ground heat exchangers at different flow rates. Based on the results, spiral shaped ground heat exchangers outperform other designs, as seen by better heat exchange rates between the fluid and the soil, which translates to a greater temperature reduction of the cooling water. This improvement not only allows for using smaller number of boreholes which saves the construction costs compared to other designs, but it also improves the coefficient of performance of the system by significantly lowering the cooling water temperature flowing back to the condenser when compared to the conventional cooling tower. This approach also eliminates cooling tower water consumption (saves about 14,500 L/day), tower noise, annual maintenance expenses, and costs for periodical cooling tower replacement. The presented findings make a significant contribution to society by offering innovative and sustainable solutions for cost reduction, environmental conservation, and energy efficiency.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77571473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Water supply is one of the imminent challenges in the coming age for mankind. The hydraulic ram pump is an eco-friendly and very cost-effective technology that can feasibly transport water from nearby water resources (such as lakes, streams, and rivers) to remote places for daily water needs. The goal of the present work was to investigate the effect of flapper valve size on pump performance. It was hypothesized that the decrease in the flapper valve size would impose more flow resistance at the waste-valve outlet diverting more water flow towards the ram pump inlet, which will increase the amount of water to the delivery tank. Based on the previous study, four flapper valve sizes (1-inch, 3/4-inch, 1/2-inch, and 1/4-inch) were selected for this study. Experiments with riser tubes were carried out using the selected flapper valve sizes. Results confirmed that the flapper valve size has a considerable influence on performance of the hydraulic ram pump. The 3/4-inch flapper valve displayed the maximum pump’s volumetric (21.7%) and energy (38.9%) efficiencies, followed by 1-inch, 1/4-inch, and 1/2-inch sized flapper valves. The flow capacity of the studied hydraulic ram pump system for 3/4-inch valve was found to be 1121 gal/day.
{"title":"Effect of Flapper Valve on the Performance of a Hydraulic Ram Pump","authors":"Ashokkumar M. Sharma, D. Banerjee, S. Pidugu","doi":"10.1115/imece2022-95901","DOIUrl":"https://doi.org/10.1115/imece2022-95901","url":null,"abstract":"\u0000 Water supply is one of the imminent challenges in the coming age for mankind. The hydraulic ram pump is an eco-friendly and very cost-effective technology that can feasibly transport water from nearby water resources (such as lakes, streams, and rivers) to remote places for daily water needs. The goal of the present work was to investigate the effect of flapper valve size on pump performance. It was hypothesized that the decrease in the flapper valve size would impose more flow resistance at the waste-valve outlet diverting more water flow towards the ram pump inlet, which will increase the amount of water to the delivery tank. Based on the previous study, four flapper valve sizes (1-inch, 3/4-inch, 1/2-inch, and 1/4-inch) were selected for this study. Experiments with riser tubes were carried out using the selected flapper valve sizes. Results confirmed that the flapper valve size has a considerable influence on performance of the hydraulic ram pump. The 3/4-inch flapper valve displayed the maximum pump’s volumetric (21.7%) and energy (38.9%) efficiencies, followed by 1-inch, 1/4-inch, and 1/2-inch sized flapper valves. The flow capacity of the studied hydraulic ram pump system for 3/4-inch valve was found to be 1121 gal/day.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81463686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
While the field of wave energy has been the subject of numerical simulation, scale model testing, and precommercial project testing for decades, wave energy technologies remain in the early stages of development and must continue to prove themselves as a promising modern renewable energy field. One of the difficulties that wave energy systems have been struggling to overcome is the design of highly efficient energy conversion systems that can convert the mechanical power derived from the oscillation of wave-activated bodies into another useful product. Often the power take-off (PTO) is defined as the single unit responsible for converting mechanical power into another usable form, such as electricity, pressurized fluid, compressed air, or others. The PTO — and the entire power conversion chain — is of great importance, as it not only affects how efficiently wave power is converted into electricity, but it also contributes to the mass, size, structural dynamics, and levelized cost of energy of the wave energy converter (WEC). Because there is no industrial standard device or devices for wave energy conversion in the marine energy industry, PTO system designs are highly variable. The majority of current WEC PTO systems incorporate a mechanical or hydraulic drive train, power generator, and an electrical control system. The challenge of WEC PTO designs is designing a mechanical-to-electrical component that can efficiently convert irregular, bidirectional, low-frequency, and low-alternating-velocity wave motions. While gross average power levels can be predicted in advance, the variable wave elevation input has to be converted into smooth electrical output and hence usually necessitates some type of energy storage system, such as battery storage, accumulators, super capacitors, etc., or other means of compensation such as an array of devices. One of the primary challenges for wave energy converter systems is the fluctuating nature of wave resources, which require WEC components to be designed to handle loads (i.e., torques, forces, and powers) that are many times greater than the average load. This approach requires a much greater PTO capacity than the average power output and often leads to a higher cost. In addition, supporting mechanical coupling and or gearing can be added to the power conversion chain to help alleviate difficulties with the transmission and control of fluctuating large loads with low frequencies (indicative of wave forcing) into smaller loads at higher frequencies (optimal for conventional electrical machine design). But these additions can quickly increase the complexity of the power conversion chain, which could result in a greater number of failure modes and increased maintenance costs; therefore, it is important to balance complexity and ruggedness. All of the previous points demonstrate how the PTO influences WEC dynamics, reliability, performance, and cost, which are critical design factors. This paper further explores t
{"title":"Review of Wave Energy Converter Power Take-Off Systems, Testing Practices, and Evaluation Metrics","authors":"Nathan Tom","doi":"10.1115/imece2022-94077","DOIUrl":"https://doi.org/10.1115/imece2022-94077","url":null,"abstract":"\u0000 While the field of wave energy has been the subject of numerical simulation, scale model testing, and precommercial project testing for decades, wave energy technologies remain in the early stages of development and must continue to prove themselves as a promising modern renewable energy field. One of the difficulties that wave energy systems have been struggling to overcome is the design of highly efficient energy conversion systems that can convert the mechanical power derived from the oscillation of wave-activated bodies into another useful product. Often the power take-off (PTO) is defined as the single unit responsible for converting mechanical power into another usable form, such as electricity, pressurized fluid, compressed air, or others. The PTO — and the entire power conversion chain — is of great importance, as it not only affects how efficiently wave power is converted into electricity, but it also contributes to the mass, size, structural dynamics, and levelized cost of energy of the wave energy converter (WEC). Because there is no industrial standard device or devices for wave energy conversion in the marine energy industry, PTO system designs are highly variable. The majority of current WEC PTO systems incorporate a mechanical or hydraulic drive train, power generator, and an electrical control system. The challenge of WEC PTO designs is designing a mechanical-to-electrical component that can efficiently convert irregular, bidirectional, low-frequency, and low-alternating-velocity wave motions. While gross average power levels can be predicted in advance, the variable wave elevation input has to be converted into smooth electrical output and hence usually necessitates some type of energy storage system, such as battery storage, accumulators, super capacitors, etc., or other means of compensation such as an array of devices. One of the primary challenges for wave energy converter systems is the fluctuating nature of wave resources, which require WEC components to be designed to handle loads (i.e., torques, forces, and powers) that are many times greater than the average load. This approach requires a much greater PTO capacity than the average power output and often leads to a higher cost. In addition, supporting mechanical coupling and or gearing can be added to the power conversion chain to help alleviate difficulties with the transmission and control of fluctuating large loads with low frequencies (indicative of wave forcing) into smaller loads at higher frequencies (optimal for conventional electrical machine design). But these additions can quickly increase the complexity of the power conversion chain, which could result in a greater number of failure modes and increased maintenance costs; therefore, it is important to balance complexity and ruggedness. All of the previous points demonstrate how the PTO influences WEC dynamics, reliability, performance, and cost, which are critical design factors. This paper further explores t","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89305662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohiodin Nazemi, R. Unnþórsson, Christiaan Richter
Seaweed is a promising organic fuel source due to its rapid growth rates, efficiency as a carbon sink, and pH resistance. It is a potential renewable fuel source since it can be transformed into high-value fuel by using either thermochemical processes such as gasification, or anaerobic digestion. However, drying the seaweed is necessary to combust, pyrolyze, or gasify seaweed. In this study, we focus on the drying process. To address this, a biomass drying cabinet was designed, constructed, tested, and experimentally evaluated. During drying runs, the temperature inside the cabinet and the moisture content of seaweed were measured. The goal of this design was to reduce the moisture content of seaweed to the optimal range for gasification-between 15% to 20%. We demonstrate the drying of fresh seaweed with an initial moisture content of around 80% to as low as 12% after 22 hours. Bladderwrack is the type of seaweed that is used in this study. Based on the results of the tests, around 19 hours of drying is needed to reduce the moisture content of seaweed to the target range (15%–20%). In conclusion, moisture reduction in Bladderwrack seaweed was analyzed and the design of the seaweed drying cabinet was evaluated. Based on our results modifications to achieve more homogeneous drying throughout the cabinet are proposed.
{"title":"Analyzing the Process of Seaweed Drying in a Drying Cabinet","authors":"Mohiodin Nazemi, R. Unnþórsson, Christiaan Richter","doi":"10.1115/imece2022-94524","DOIUrl":"https://doi.org/10.1115/imece2022-94524","url":null,"abstract":"\u0000 Seaweed is a promising organic fuel source due to its rapid growth rates, efficiency as a carbon sink, and pH resistance. It is a potential renewable fuel source since it can be transformed into high-value fuel by using either thermochemical processes such as gasification, or anaerobic digestion. However, drying the seaweed is necessary to combust, pyrolyze, or gasify seaweed. In this study, we focus on the drying process. To address this, a biomass drying cabinet was designed, constructed, tested, and experimentally evaluated. During drying runs, the temperature inside the cabinet and the moisture content of seaweed were measured. The goal of this design was to reduce the moisture content of seaweed to the optimal range for gasification-between 15% to 20%. We demonstrate the drying of fresh seaweed with an initial moisture content of around 80% to as low as 12% after 22 hours. Bladderwrack is the type of seaweed that is used in this study. Based on the results of the tests, around 19 hours of drying is needed to reduce the moisture content of seaweed to the target range (15%–20%). In conclusion, moisture reduction in Bladderwrack seaweed was analyzed and the design of the seaweed drying cabinet was evaluated. Based on our results modifications to achieve more homogeneous drying throughout the cabinet are proposed.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"100 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91180578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Developing a viable data-driven policy for the management of electrical-energy consumption in campus residences is contingent on the proper knowledge of the electricity usage pattern and its predictability. In this study, an adaptive neuro-fuzzy inference systems (ANFIS) was developed to model the electrical energy consumption of students’ residence using the University of Johannesburg, South Africa as a case study. The model was developed based on the environmental conditions vis-à-vis meteorological parameters namely temperature, wind speed, and humidity of the respective days as the input variables while electricity consumption (kWh) was used as the output variable. The fuzzy c-means (FCM) is a type of clustering technique that is preferred owing to its speed boost capacity. The best FCM-clustered ANFIS-model based on a range of 2–10 clusters was selected after evaluating their performance using relevant statistical metrics namely; mean absolute percentage error (MAPE), root mean square error (RMSE), and mean absolute deviation (MAD). FCM-ANFIS with 7 clusters outperformed all other models with the least error and highest accuracy. The RMSE, MAPE, MAD, and R2-values of the best models are 0.043, 0.65, 1.051, and 0.9890 respectively. The developed model will assist in optimizing energy consumption and assist in designing and sizing alternative energy systems for campus residences.
{"title":"Prediction of Electrical Energy Consumption in University Campus Residence Using FCM-Clustered Neuro-Fuzzy Model","authors":"O. Adeleke, T. Jen","doi":"10.1115/imece2022-96793","DOIUrl":"https://doi.org/10.1115/imece2022-96793","url":null,"abstract":"\u0000 Developing a viable data-driven policy for the management of electrical-energy consumption in campus residences is contingent on the proper knowledge of the electricity usage pattern and its predictability. In this study, an adaptive neuro-fuzzy inference systems (ANFIS) was developed to model the electrical energy consumption of students’ residence using the University of Johannesburg, South Africa as a case study. The model was developed based on the environmental conditions vis-à-vis meteorological parameters namely temperature, wind speed, and humidity of the respective days as the input variables while electricity consumption (kWh) was used as the output variable. The fuzzy c-means (FCM) is a type of clustering technique that is preferred owing to its speed boost capacity. The best FCM-clustered ANFIS-model based on a range of 2–10 clusters was selected after evaluating their performance using relevant statistical metrics namely; mean absolute percentage error (MAPE), root mean square error (RMSE), and mean absolute deviation (MAD). FCM-ANFIS with 7 clusters outperformed all other models with the least error and highest accuracy. The RMSE, MAPE, MAD, and R2-values of the best models are 0.043, 0.65, 1.051, and 0.9890 respectively. The developed model will assist in optimizing energy consumption and assist in designing and sizing alternative energy systems for campus residences.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91365203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Khan, Sambhaji T. Kadam, A. Kyriakides, Ibrahim Hassan, A. Papadopoulos, Mohammad Sohel Rahman, P. Seferlis
Most of the absorbent-refrigerant pairings are evaluated considering single-effect vapour absorption refrigeration (VAR) cycle. The coefficient of performance (COP) based modelling of VAR enables its quick performance evaluation. The development of efficient and environmentally benign fluid pairing is required to replace conventional refrigerants. Operating parameters-based COP models are scarce for single-effect VAR systems, and fewer correlations are available for the COP estimation. The paper compares five performance-based models reported in the literature for operating absorption cooling systems with various refrigerant and absorbent pairing. The comprehensive mean absolute percentage error (MAPE) analysis was performed for five reported correlations for more than 1601 data points of different fluid pairings. Results revealed that RMSD and MAPE values seem significantly higher for the reported correlations apart from the recently developed COP correlation accounted for fluid parameters in prediction. This indicates that the earlier reported correlations only accounted for the specific fluid pairing and could not incorporate different fluid pairing, which has been considered a recently reported correlation that resulted in the significantly improved prediction ability for COP. The finding from this study highlighted that the newly registered COP prediction correlation could be beneficial for developing new single-effect VAR cycles as it accounted for both the operating parameters and fluid parameters.
{"title":"Comparative Analysis of Coefficient of Performance (COP) Correlations of Single-Effect Vapor Absorption Refrigeration (VAR) Cycle","authors":"M. Khan, Sambhaji T. Kadam, A. Kyriakides, Ibrahim Hassan, A. Papadopoulos, Mohammad Sohel Rahman, P. Seferlis","doi":"10.1115/imece2022-93943","DOIUrl":"https://doi.org/10.1115/imece2022-93943","url":null,"abstract":"\u0000 Most of the absorbent-refrigerant pairings are evaluated considering single-effect vapour absorption refrigeration (VAR) cycle. The coefficient of performance (COP) based modelling of VAR enables its quick performance evaluation. The development of efficient and environmentally benign fluid pairing is required to replace conventional refrigerants. Operating parameters-based COP models are scarce for single-effect VAR systems, and fewer correlations are available for the COP estimation. The paper compares five performance-based models reported in the literature for operating absorption cooling systems with various refrigerant and absorbent pairing. The comprehensive mean absolute percentage error (MAPE) analysis was performed for five reported correlations for more than 1601 data points of different fluid pairings. Results revealed that RMSD and MAPE values seem significantly higher for the reported correlations apart from the recently developed COP correlation accounted for fluid parameters in prediction. This indicates that the earlier reported correlations only accounted for the specific fluid pairing and could not incorporate different fluid pairing, which has been considered a recently reported correlation that resulted in the significantly improved prediction ability for COP. The finding from this study highlighted that the newly registered COP prediction correlation could be beneficial for developing new single-effect VAR cycles as it accounted for both the operating parameters and fluid parameters.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88489393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Banerjee, I. Abu-Mahfouz, Jianyan Tian, A. E. Rahman
The need to accurately estimate wind power is essential to the design and deployment of individual wind turbines and wind farms. The estimation problem is framed as wind power curve modeling. Lately, machine learning techniques have been used to model power curves and provide power estimates. Such models rely on the fact that all outliers are removed from the raw wind data before they are used in modeling and estimation since outliers can adversely affect performance. However, generating outlier-free data is not always possible. Robust models and robust objective functions can be two effective ways to obtain accurate power curves in the presence of outliers. In this paper, a robust density-based clustering technique (DBSCAN) to first identify outliers in the dataset is proposed, followed by artificial neural network (ANN) models that are trained using the outlier-free data to obtain accurate power curve estimates. ANNs are trained using a range of optimization methods and are compared in this study. Preliminary results show the proposed method is superior to probabilistic models that use error-functions to generate accurate power curves and that the proposed hybrid model can generate more accurate power output estimations in the presence of outliers compared to deterministic models such as integrated curve fitting models that are known to be robust.
{"title":"A Robust Hybrid Machine Learning-Based Modeling Technique for Wind Power Production Estimates","authors":"A. Banerjee, I. Abu-Mahfouz, Jianyan Tian, A. E. Rahman","doi":"10.1115/imece2022-94173","DOIUrl":"https://doi.org/10.1115/imece2022-94173","url":null,"abstract":"\u0000 The need to accurately estimate wind power is essential to the design and deployment of individual wind turbines and wind farms. The estimation problem is framed as wind power curve modeling. Lately, machine learning techniques have been used to model power curves and provide power estimates. Such models rely on the fact that all outliers are removed from the raw wind data before they are used in modeling and estimation since outliers can adversely affect performance. However, generating outlier-free data is not always possible. Robust models and robust objective functions can be two effective ways to obtain accurate power curves in the presence of outliers. In this paper, a robust density-based clustering technique (DBSCAN) to first identify outliers in the dataset is proposed, followed by artificial neural network (ANN) models that are trained using the outlier-free data to obtain accurate power curve estimates. ANNs are trained using a range of optimization methods and are compared in this study. Preliminary results show the proposed method is superior to probabilistic models that use error-functions to generate accurate power curves and that the proposed hybrid model can generate more accurate power output estimations in the presence of outliers compared to deterministic models such as integrated curve fitting models that are known to be robust.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89387373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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