Exergy analysis and igcc plant technology to improve the efficiency and to re...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Selection of prime mover type was investigated for use in combined cooling, heat and power systems. Selection was determined from comparison of performance criteria for economic, energy and emissions savings. Simulations were run for three different types of prime movers in one climate zone and compared to a reference case with a typical separate heating and power system in the same climate zone. A hybrid load following method was implemented, with a suggested improvement. Performance parameters were compared and results indicated emissions and energy savings for all three prime movers. The prime mover types were reciprocating internal combustion engine (ICE), micro-turbine and phosphoric acid fuel cell. The climate zone was chosen to be a cold, humid climate represented by Chicago, IL. Economic savings were seen for both the ICE and micro-turbines. Emissions savings for carbon, nitrogen oxides and methane, for all three types, were greater than 9%, 12%, and 13%, respectively. Primary energy consumption savings for all three were greater than 8%.
Thermal Characteristics of Different Shaped Fin Protracted Heat Exchanger in ...YogeshIJTSRD
The current presents looks at exhaust gases potential to recover low grade waste heat energy from internal combustion engines ICEs . A Prolonged Fin Counter Flow Heat Exchange PFCHE double tube was planned, analyzed, and supplied with water as working fluids to achieve this objective. The structure of a double pipe, Protracted Fin Heat Exchanger PFCHE , which performs a simulation study, is derived with exact measurements from one by Rajesh Ravi et al. 2020 research scholar, and then different shapes of the fin profiles were introduced in the designs suggested. The Fluent 17.0 is used for numerical analysis. The CFD results showing that the PFCHE with triangular fin outperforms the PFCHE with circular fin, and previous studies by Rajesh Ravi et al. 2020 showing that the PFCHE with triangular fin outperforms the PFCHE with circular fin. When compared to the PFCHE with circular fin, the PFCHE net heat transfer rate is 1.76 percent higher and 2.82 percent higher than Rajesh Ravi et al. 2020 report. Prof. Ranjeet Arya | Rahul Ade "Thermal Characteristics of Different Shaped Fin Protracted Heat Exchanger in Diesel Engine Exhaust using CFD" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-3 , April 2021, URL: https://www.ijtsrd.com/papers/ijtsrd39939.pdf Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/39939/thermal-characteristics-of-different-shaped-fin-protracted-heat-exchanger-in-diesel-engine-exhaust-using-cfd/prof-ranjeet-arya
Combined heat and power - optimal power flow based on thermodynamic model wit...IJECEIAES
Oil fields produce associated petroleum and wet gas, which can be mixed with commercial natural gas as fuel. Associated petroleum and wet gas are a low cost, low quality fuel, whereas commercial natural gas is the opposite. Two parameters are affected by this mixture: the fuel cost and the power – steam output of gas turbine – heat recovery steam generators. This research develops a Unit Commitment and Optimal Power Flow model based on Mixed Integer Nonlinear Programming to optimize combined heat and power cost by considering the optimal mixture between associated petroleum - wet gas and commercial natural gas. A thermodynamic model is used to represent the performance of gas turbine – heat recovery steam generators when subjected to different fuel mixtures. The results show that the proposed model can optimize cost by determining the most efficient power – steam dispatch and optimal fuel mixture. Furthermore, the optimization model can analyse the trade-off between power system losses, steam demand and associated - wet gas utilization.
Exergy analysis and igcc plant technology to improve the efficiency and to re...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Selection of prime mover type was investigated for use in combined cooling, heat and power systems. Selection was determined from comparison of performance criteria for economic, energy and emissions savings. Simulations were run for three different types of prime movers in one climate zone and compared to a reference case with a typical separate heating and power system in the same climate zone. A hybrid load following method was implemented, with a suggested improvement. Performance parameters were compared and results indicated emissions and energy savings for all three prime movers. The prime mover types were reciprocating internal combustion engine (ICE), micro-turbine and phosphoric acid fuel cell. The climate zone was chosen to be a cold, humid climate represented by Chicago, IL. Economic savings were seen for both the ICE and micro-turbines. Emissions savings for carbon, nitrogen oxides and methane, for all three types, were greater than 9%, 12%, and 13%, respectively. Primary energy consumption savings for all three were greater than 8%.
Thermal Characteristics of Different Shaped Fin Protracted Heat Exchanger in ...YogeshIJTSRD
The current presents looks at exhaust gases potential to recover low grade waste heat energy from internal combustion engines ICEs . A Prolonged Fin Counter Flow Heat Exchange PFCHE double tube was planned, analyzed, and supplied with water as working fluids to achieve this objective. The structure of a double pipe, Protracted Fin Heat Exchanger PFCHE , which performs a simulation study, is derived with exact measurements from one by Rajesh Ravi et al. 2020 research scholar, and then different shapes of the fin profiles were introduced in the designs suggested. The Fluent 17.0 is used for numerical analysis. The CFD results showing that the PFCHE with triangular fin outperforms the PFCHE with circular fin, and previous studies by Rajesh Ravi et al. 2020 showing that the PFCHE with triangular fin outperforms the PFCHE with circular fin. When compared to the PFCHE with circular fin, the PFCHE net heat transfer rate is 1.76 percent higher and 2.82 percent higher than Rajesh Ravi et al. 2020 report. Prof. Ranjeet Arya | Rahul Ade "Thermal Characteristics of Different Shaped Fin Protracted Heat Exchanger in Diesel Engine Exhaust using CFD" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-3 , April 2021, URL: https://www.ijtsrd.com/papers/ijtsrd39939.pdf Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/39939/thermal-characteristics-of-different-shaped-fin-protracted-heat-exchanger-in-diesel-engine-exhaust-using-cfd/prof-ranjeet-arya
Combined heat and power - optimal power flow based on thermodynamic model wit...IJECEIAES
Oil fields produce associated petroleum and wet gas, which can be mixed with commercial natural gas as fuel. Associated petroleum and wet gas are a low cost, low quality fuel, whereas commercial natural gas is the opposite. Two parameters are affected by this mixture: the fuel cost and the power – steam output of gas turbine – heat recovery steam generators. This research develops a Unit Commitment and Optimal Power Flow model based on Mixed Integer Nonlinear Programming to optimize combined heat and power cost by considering the optimal mixture between associated petroleum - wet gas and commercial natural gas. A thermodynamic model is used to represent the performance of gas turbine – heat recovery steam generators when subjected to different fuel mixtures. The results show that the proposed model can optimize cost by determining the most efficient power – steam dispatch and optimal fuel mixture. Furthermore, the optimization model can analyse the trade-off between power system losses, steam demand and associated - wet gas utilization.
IRJET-Detailed Energy Audit in a Captive Cogeneration PlantIRJET Journal
D.Rajani Kant , B.Sudheer Prem Kumar, N.Ravi Kumar, R.Virendra,J.Suresh Babu " Detailed Energy Audit in a Captive Cogeneration Plant ", International Research Journal of Engineering and Technology (IRJET), Volume2,issue-01 April 2015.e-ISSN:2395-0056, p-ISSN:2395-0072. www.irjet.net
Abstract
The rate of exploitation of the energy resources has been expanding over time and resulted in reduction of fossil fuel reserves. Efficiency of all resources is crucial both in environmental and economic sense. Using energy inefficiently creates waste in all the world’s economies. It has environmental impacts with regional, local and global implications.The key object is to adopt energy management in every field in order to reduce the wastage of energy sources and cost effectiveness without affecting productivity and growth.
ESTIMATION AND ANALYSIS OF CYCLE EFFICIENCY FOR SHELL AND TUBE HEAT EXCHANGER...IAEME Publication
Shell and tube Heat exchanger (STHE) is one of the most common and widely used energy transporter suited for domestic usages as well as industrial applications. In this paper, we consider shell and tube heat exchanger as a device with known input and output parameters. This work utilizes imperative design constraints like tube configuration, fluids, surface and temperature (constant magnitude) as input parameters and energetic cycle efficiency considered as desired output parameter depicting performance of the device. The model was trained and tested by proposed Genetic algorithm (GA) technique. This entire computational procedure is implemented in MATLAB platform.
Iris Publishers- Journal of Engineering Sciences | Performance and Design Opt...IrisPublishers
The aim of this work is to optimize the design and performance of solar powered γ Stirling engine based on genetic algorithm (GA). A second-order mathematical model which includes thermal losses coupled with genetic algorithm GA has been developed and used to find the best values for different design variables. The physical geometry of the γ Stirling engine has been used as an objective variable in the genetic algorithm GA to determine the optimal parameters. The design geometry of the heat exchanger was considered to be the objective variable. The heater slots height, heater effective length, cooler slots height, cooler effective length, re-generator foil unrolled length and re-generator effective length are assumed to be the objective variables. Also, three different types of working fluids have been used in the model simulation to investigate the effect of the different working fluid on the engine performance. The comparison between the results obtained from the simulation by using the original parameters and the results from the optimized parameters when the engine was powered by solar energy; the higher temperature was 923 K applied to the working fluid when the air, helium, and hydrogen were used as working fluid. The engine power increases from 140.58 watts to 228.54 watts, and it is enhanced by approximately 50%, when the heating temperature is 923 K and the air is used as working fluid. The result showed that the working temperature is one of the most important parameters; because the output power increases by increasing of the hot side temperature.
A computer Model of Fuel Consumption Estimation for Different Agricultural Fa...Agriculture Journal IJOEAR
Abstract— A computer programme was developed to estimate fuel consumption rate in liter per hour for medium agric-tractor with load and without load under different soil conditions. The programme enables the user to insert the input data through the input interface and obtain the output rapidly. The model was verified, validated and tested by using data from literature and a private agricultural services company in Sudan, for two types of heavy disc harrow (AH280, BH360), (H56,CH65C) driven by challenger track tractors, on the other hand, seeder and ridger separately operated with wheeled 4WD tractors. It was also tested by data from Sennar Agricultural Services Center, using heavy disc harrow with 4WD tractor. The sensitivity analysis showed that the change in any of input parameters, e.g. speed, unit draft, engine power affected directly the estimated fuel consumption rate. Accordingly, the computer programme performed very well in estimating fuel consumption and can be used as a good guide to the farmer or any interested person in machinery management and for quick decision-making.
Webinar: Post-combusion carbon capture - Thermodynamic modellingGlobal CCS Institute
Vladimir Vaysman from WorleyParsons gave a Global CCS Institute webinar on 12 March 2013 to present a generic methodology developed to provide independent verification of the impact on a coal–fired power station of installing and operating a post-combustion capture plant.
Vladimir illustrated the methodology using Loy Yang A power station in Australia in five different scenarios that cover carbon capture, air cooling, coal drying and plant optimisation.
The methodology offers a sound approach to provide performance data and protect technology vendor IP while also providing confidence to the wider CCS community to evaluate a project.
Vladimir is a Project Manager with more than 31 years of engineering experience, including 14 years with WorleyParsons. He has undertaken an array of design and analysis studies and developed significant expertise across a range of technologies, from pulverised coal and circulating fluidised bed, to integrated gasification combined cycle and carbon capture. Vladimir has participated in projects in Australia, Bulgaria, Canada, China, Kazakhstan, Korea, Malaysia, Moldova, New Zealand, Poland, Romania, Russia and Ukraine.
The development of utility-scale wind farms that can produce energy at a cost comparable to that of conventional energy resources presents significant challenges to today’s wind energy industry. The consideration of the combined impact of key design and environmental factors on the performance of a wind farm is a crucial part of the solution to this challenge. The state of the art in optimal wind project planning includes wind farm layout design and more recently turbine selection. The scope of farm layout optimization and the predicted wind project performance however depends on several other critical site-scale factors, which are often not explicitly accounted for in the wind farm planning literature. These factors include: (i) the land area per MW installed (LAMI), and (ii) the nameplate capacity (in MW) of the farm. In this paper, we develop a framework to quantify and analyze the roles of these crucial design factors in optimal wind farm planning. A set of sample values of LAMI and installed farm capacities is first defined. For each sample farm definition, simultaneous optimization of the farm layout and turbine selection is performed to maximize the farm capacity factor (CF). To this end, we apply the recently de- veloped Unrestricted Wind Farm Layout Optimization (UWFLO) method. The CF of the optimized farm is then represented as a function of the nameplate capacity and the LAMI, using response surface methodologies. The variation of the optimized CF with these site-scale factors is investigated for a representative wind site in North Dakota. It was found that, a desirable CF value corresponds to a cutoff “LAMI vs nameplate capacity” curve – the identification of this cutoff curve is critical to the development of an economically viable wind energy project.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Photovoltaic (PV) cell from solar energy is one of the most widely adopted renewable energy source and commercially available system that can be used in various applications. More appealing application of PV arrays used in thermoelectric (TE) device was it can convert solar thermal energy from temperature difference into electric energy to act as power generators. In this study, a theoretical model is developed by using conducting steady state energy analysis of a PVT-TE air collector. The matrix inversion method is used to obtain energy balance equation. The effect of various parameters also investigated. The mass flow rate of range 0.01 kg/s to 0.05 kg/s and solar intensity of 400 W/m2, 600 W/m2 and 800 W/m2 was used to obtain outlet temperature, To in the range about 28.9oC to 43.7oC and PV temperature, Tp about 35.3oC to 60oC.
IRJET-Detailed Energy Audit in a Captive Cogeneration PlantIRJET Journal
D.Rajani Kant , B.Sudheer Prem Kumar, N.Ravi Kumar, R.Virendra,J.Suresh Babu " Detailed Energy Audit in a Captive Cogeneration Plant ", International Research Journal of Engineering and Technology (IRJET), Volume2,issue-01 April 2015.e-ISSN:2395-0056, p-ISSN:2395-0072. www.irjet.net
Abstract
The rate of exploitation of the energy resources has been expanding over time and resulted in reduction of fossil fuel reserves. Efficiency of all resources is crucial both in environmental and economic sense. Using energy inefficiently creates waste in all the world’s economies. It has environmental impacts with regional, local and global implications.The key object is to adopt energy management in every field in order to reduce the wastage of energy sources and cost effectiveness without affecting productivity and growth.
ESTIMATION AND ANALYSIS OF CYCLE EFFICIENCY FOR SHELL AND TUBE HEAT EXCHANGER...IAEME Publication
Shell and tube Heat exchanger (STHE) is one of the most common and widely used energy transporter suited for domestic usages as well as industrial applications. In this paper, we consider shell and tube heat exchanger as a device with known input and output parameters. This work utilizes imperative design constraints like tube configuration, fluids, surface and temperature (constant magnitude) as input parameters and energetic cycle efficiency considered as desired output parameter depicting performance of the device. The model was trained and tested by proposed Genetic algorithm (GA) technique. This entire computational procedure is implemented in MATLAB platform.
Iris Publishers- Journal of Engineering Sciences | Performance and Design Opt...IrisPublishers
The aim of this work is to optimize the design and performance of solar powered γ Stirling engine based on genetic algorithm (GA). A second-order mathematical model which includes thermal losses coupled with genetic algorithm GA has been developed and used to find the best values for different design variables. The physical geometry of the γ Stirling engine has been used as an objective variable in the genetic algorithm GA to determine the optimal parameters. The design geometry of the heat exchanger was considered to be the objective variable. The heater slots height, heater effective length, cooler slots height, cooler effective length, re-generator foil unrolled length and re-generator effective length are assumed to be the objective variables. Also, three different types of working fluids have been used in the model simulation to investigate the effect of the different working fluid on the engine performance. The comparison between the results obtained from the simulation by using the original parameters and the results from the optimized parameters when the engine was powered by solar energy; the higher temperature was 923 K applied to the working fluid when the air, helium, and hydrogen were used as working fluid. The engine power increases from 140.58 watts to 228.54 watts, and it is enhanced by approximately 50%, when the heating temperature is 923 K and the air is used as working fluid. The result showed that the working temperature is one of the most important parameters; because the output power increases by increasing of the hot side temperature.
A computer Model of Fuel Consumption Estimation for Different Agricultural Fa...Agriculture Journal IJOEAR
Abstract— A computer programme was developed to estimate fuel consumption rate in liter per hour for medium agric-tractor with load and without load under different soil conditions. The programme enables the user to insert the input data through the input interface and obtain the output rapidly. The model was verified, validated and tested by using data from literature and a private agricultural services company in Sudan, for two types of heavy disc harrow (AH280, BH360), (H56,CH65C) driven by challenger track tractors, on the other hand, seeder and ridger separately operated with wheeled 4WD tractors. It was also tested by data from Sennar Agricultural Services Center, using heavy disc harrow with 4WD tractor. The sensitivity analysis showed that the change in any of input parameters, e.g. speed, unit draft, engine power affected directly the estimated fuel consumption rate. Accordingly, the computer programme performed very well in estimating fuel consumption and can be used as a good guide to the farmer or any interested person in machinery management and for quick decision-making.
Webinar: Post-combusion carbon capture - Thermodynamic modellingGlobal CCS Institute
Vladimir Vaysman from WorleyParsons gave a Global CCS Institute webinar on 12 March 2013 to present a generic methodology developed to provide independent verification of the impact on a coal–fired power station of installing and operating a post-combustion capture plant.
Vladimir illustrated the methodology using Loy Yang A power station in Australia in five different scenarios that cover carbon capture, air cooling, coal drying and plant optimisation.
The methodology offers a sound approach to provide performance data and protect technology vendor IP while also providing confidence to the wider CCS community to evaluate a project.
Vladimir is a Project Manager with more than 31 years of engineering experience, including 14 years with WorleyParsons. He has undertaken an array of design and analysis studies and developed significant expertise across a range of technologies, from pulverised coal and circulating fluidised bed, to integrated gasification combined cycle and carbon capture. Vladimir has participated in projects in Australia, Bulgaria, Canada, China, Kazakhstan, Korea, Malaysia, Moldova, New Zealand, Poland, Romania, Russia and Ukraine.
The development of utility-scale wind farms that can produce energy at a cost comparable to that of conventional energy resources presents significant challenges to today’s wind energy industry. The consideration of the combined impact of key design and environmental factors on the performance of a wind farm is a crucial part of the solution to this challenge. The state of the art in optimal wind project planning includes wind farm layout design and more recently turbine selection. The scope of farm layout optimization and the predicted wind project performance however depends on several other critical site-scale factors, which are often not explicitly accounted for in the wind farm planning literature. These factors include: (i) the land area per MW installed (LAMI), and (ii) the nameplate capacity (in MW) of the farm. In this paper, we develop a framework to quantify and analyze the roles of these crucial design factors in optimal wind farm planning. A set of sample values of LAMI and installed farm capacities is first defined. For each sample farm definition, simultaneous optimization of the farm layout and turbine selection is performed to maximize the farm capacity factor (CF). To this end, we apply the recently de- veloped Unrestricted Wind Farm Layout Optimization (UWFLO) method. The CF of the optimized farm is then represented as a function of the nameplate capacity and the LAMI, using response surface methodologies. The variation of the optimized CF with these site-scale factors is investigated for a representative wind site in North Dakota. It was found that, a desirable CF value corresponds to a cutoff “LAMI vs nameplate capacity” curve – the identification of this cutoff curve is critical to the development of an economically viable wind energy project.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Photovoltaic (PV) cell from solar energy is one of the most widely adopted renewable energy source and commercially available system that can be used in various applications. More appealing application of PV arrays used in thermoelectric (TE) device was it can convert solar thermal energy from temperature difference into electric energy to act as power generators. In this study, a theoretical model is developed by using conducting steady state energy analysis of a PVT-TE air collector. The matrix inversion method is used to obtain energy balance equation. The effect of various parameters also investigated. The mass flow rate of range 0.01 kg/s to 0.05 kg/s and solar intensity of 400 W/m2, 600 W/m2 and 800 W/m2 was used to obtain outlet temperature, To in the range about 28.9oC to 43.7oC and PV temperature, Tp about 35.3oC to 60oC.
Avanços na Medicina: Medicina Regenerativa, Ortomolecular, Ozonioterapia e A...Clínica Higashi
Dr. Tsutomu Higashi, médico pioneiro na medicina ortomolecular no Brasil, fundador da Clínica Higashi explica sobre avanços da medicina com a Medicina Regenerativa, Ortomolecular, Ozonioterapia e Antienvelhecimento. Dr. Higashi explica que somente mudando o paradigma atual da medicina é que se pode oferecer melhores resultados na saúde do paciente. Mais informações www.clinicahigashi.com.br
To be transmitted, data must be transformed to electromagnetic signals
Data can be analog or digital. Analog data are continuous and take continuous values. Digital data have discrete states and take on discrete values.
Signals can be analog or digital. Analog signals can have an infinite number of values in a range; digital signals can have only a limited number of values.
Intoxicação por metais pesados e técnica do BDORTClínica Higashi
Dr Tsutomu Higashi, médico pesquisador da medicina ortomolecular explica sobre a intoxicação de metais pesados no meio ambiente e no organismo. www.ortomoleculardrhigashi.med.br
Aula sobre Ecocolordoppler Transcraniano: método e indicação ministrada pelo médico neurologista Dr. Rafael Higashi, no Hospital Pan Americano no Rio de Janeiro.
www.estimulacaoneurologica.com.br
Aula sobre Dor Lombar: Como iniciar o raciocínio médico ? apresentado por Dr. Rafael Higashi, médico neurologista com especialização em dor pela Universidade de Nova York, EUA ministrada para o grupo de estudo da clínica de dor Centro Médico Athenas. www.estimulacao neurologica.com.br
Aula sobre as ataxias ou distúrbios cerebelares ministrado por Dr. Rafael Higashi (neurologista) para os residêntes de neurologia do INDC- UFRJ em 2005.
www.estimulacaoneurologica.com.br
The International Journal of Mechanical Engineering Research and Technology is an international online journal published Quarterly offers fast publication schedule whilst maintaining rigorous peer review. The use of recommended electronic formats for article delivery expedites the process of All submitted research articles are subjected to immediate rapid screening by the editors consultation with the Editorial Board or others working in the field of appropriate to ensure that they are likely to be the level of interest and importance of appropriate for the journal.
international research journal of engineering and technology 3 nov.pdfnareshkotra
The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published Quarterly offers a fast publication schedule whilst maintaining a proper peer review and the use of recommended electronic formats for an article delivery expedites the process of All submitted research articles are subjected to an immediate rapid screening by the editors consultation with the Editorial Board or others working in the field as assure that they are likely to be the level of interest and importance of appropriate for the journal.
The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published Quarterly offers a fast publication schedule with whilst maintaining a rigorous peer review and the use of recommended electronic formats for article delivery expedites the process of All submitted research articles are subjected to immediate rapid screening by the editors consultation with the Editorial Board or others working in the field as appropriate to ensure they are likely to be the level of interest and importance appropriate for the journal.
The International Journal of Mechanical Engineering Research and Technology is an international online journal in English published Quarterly offers a fast publication schedule whilst maintaining rigorous peer review the use of recommended electronic formats for article delivery expedites the process All submitted research articles are subjected to immediate rapid screening by the editors consultation with the Editorial Board or others working in the field as appropriate to ensure they are likely to be the level of interest and importance appropriate for the journal.
Exergy analysis as a tool for energy efficiency improvements in the Tanzanian...Patrick VanSchijndel
The story behind energy efficiency in industrial processes is productivity, industrial competitiveness, jobs, and a clean environment. A method for energy efficiency evaluation is to carry out an energy analysis, a so called First-Law analysis. With such an energy-audit, however, it is impossible to compare different kinds of energies like electrical energy, mechanical work, high and low temperature streams, etc. A better tool for comparing different kinds or qualities of energy is exergy analysis in which the quality or exergy of all energy streams is calculated. In this way the energies are calculated and compared in a more scientifically correct and accurate manner. Advantages of the exergy analysis is to get a better understanding of the energy losses in, parts of, an industrial process, which means it is easier to find out in what part of a process energy use can be decreased.
In this paper two analyses of energy intensive processes in Tanzania and Zambia are described. First, the energy and exergy analyses of the Tanzania Portland Cement Co., Ltd., at Wazo Hill in Dar es Salaam are presented. It was possible to perform an exergy analysis using available energy and mass balance data and some basic thermodynamic data like enthalpies and Gibbs Free energies. The analysis predicted that the energy use in the cement production could be decreased by 15% and higher by improving the kiln process and by installing new equipment (pre- calciners). Secondly, energy evaluations concerning sugar production were performed. For heat-exchangers, exergy analysis identified temperature difference between the hot and the cold streams as a critical parameter in equipment efficiency calculations. A big problem affecting this temperature difference in heat exchangers is fouling, the formation of solid deposits on heat exchanger surfaces. Elimination or minimising fouling can lead to low exergy losses in heat exchangers and hence high equipment effectiveness. A research project formulated to investigate the problem of fouling in the sugar industry in Zambia is described.
Generally it can be concluded that an exergy analysis is more accurate than a thermal analysis because not only quantity but also quality of the energy used is calculated.
Scope of Improving Energy Utilization in Coal Based Co-Generation on Thermal ...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
Hydrogen storage for micro-grid application: a framework for ranking fuel ce...IJECEIAES
To securely address energy shortage and various environmental issues attributed to fossil fuel, the adoption of renewable energy is growing across the globe. However, wind and solar which form the bulk of the emerging renewable energy for micro-grid applications are intermittent and need energy storage device for backup. Due to its environmentally friendly nature, the use of hydrogen as storage mechanism is now being explored for micro-grid applications. However, due to the various technical criteria attributed to various fuel cell (FC) technologies used for hydrogen production, selecting the most suitable alternative remains a challenge. This study uses evaluation based on distance from average solution, a multicriteria decision making tool to rank FC technologies that can be used to produce of hydrogen energy storage in micro-grid applications. The analysis was based on 4 FC technologies and 6 technical criteria. The results of the study show that the most preferred FC technology for micro-grid application is the polymeric electrolyte membrane while the least preferred is molten carbonate FC. It is expected that future analysis would explore the inclusion of socio-economic criteria in the evaluation of the most preferred FC technology for micro-grid application.
A review of thermoelectric generators for waste heat recovery in marine appli...ManabSaha6
Power and energy demands are increasing for current and future marine vessels (including commercial and naval ships), while the maritime industry is facing challenges associated with rising fuel costs and tightening emission legislation. To mitigate the challenges, the installed power generation unit (i.e., engine) will likely need to be complemented by a mix of energy-efficient plant, waste-energy recovery technologies, smart-power system configuration, and energy-storage technologies.
In our recently published review article in Sustainable Energy Technologies and Assessments (SETA) journal, we have provided insights (including concepts, applications and technological advancements) into Thermoelectric Generators (TEG) as waste heat recovery (WHR) technology applicable to maritime platforms and to address the challenges faced by current and future marine vehicles.
This paper has covered more recent advances in TEG application to marine platforms and has demonstrated the potential of TEG-based technology on maritime platforms’ capability enhancement and guides future research.
I presented at Argus Methanol Forum yesterday. Talked about methanol as a renewable liquid fuel option that can offer efficient vehicle for large scale utilization and monetization of renewable energy resources.
Analysis of Boiler Performance with HBS, Variation of Boiler Loads and Excess...ijtsrd
The fundamental intention of this review is to recognize greatest energy misfortune regions in any nuclear energy plants and produce an arrangement to decrease them utilizing exergy investigation. For this examination, direct energy estimation of the general plant and decide the efficiencies and energy misfortunes of the relative multitude of important portions of the nuclear energy plant. Then, at that point, discover those regions where energy misfortunes are happening most extreme and afterward altered it for productive and compelling improvement in nuclear energy plant. The review was done at Thermal power station of Vardhman Yarns at Mandideep and evaporator segment of nuclear energy station is considered with the end area of exergy investigation. The kettle of a power plant is the best segment in taking out exergy. The outcomes shows that heater misfortunes and kettle productivity relies upon evaporator burden and level of overabundance air. The current examination show consequences of 30 mw power plant. Tests were led utilizing 0 , 20 , 30 and 40 of overabundance air and 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 evaporator loads. In the current examination kettle house gives the best outcomes at 0 abundance air with greatest heater load similar to the evaporator effectiveness 86.7 are concerned. With 0 abundance air the evaporator productivity is viewed as greatest 86.7 , which gives least hotness misfortune. Manu Sengar | Dr. Shyam Birla "Analysis of Boiler Performance with HBS, Variation of Boiler Loads and Excess Air" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-2 , February 2022, URL: https://www.ijtsrd.com/papers/ijtsrd49193.pdf Paper URL: https://www.ijtsrd.com/engineering/other/49193/analysis-of-boiler-performance-with-hbs-variation-of-boiler-loads-and-excess-air/manu-sengar
Fabrication of new ceramics nanocomposites for solar energy storage and releasejournalBEEI
The carbides nanostructures have huge applications in renewable energy fields such as the saving of solar energy and release which attributed to the good their properties (thermal, electrical, mechanical, optical and chemical). So, in this paper, the solar energy storage and release of carbides nanoparticles/water for building heating and cooling applications have been investigated with different concentrations of metals carbides nanoparticles (tantalum carbide-silicon carbide). The results showed that the melting and solidification times for thermal energy storage and release decrease with an increase (TaC-SiC) nanoparticles concentrations. From the obtained results, the TaC/SiC nanostructures/ water nano-system are considered as promising materials for solar energy storage and release with high efficiency and high gain (more than 50% compare with the water). Also, the TaC/SiC may be used for heating and cooling fields with good performance and high gain.
Modelling of fouling in heat exchangers using the Artificial Neural Network A...AI Publications
In this paper, modelling by neural networks was used for obtaining a model for the calculation of fouling factors in heat exchangers. The heat exchangers used in this study are a series of four exchangers where a model was obtained for each exchanger after due estimation of its heat load. The basic theme of this paper is the investigation of fouling factors and the determination of relevant indicators followed by combining design and operation factors along with fouling factors in a mathematical model that may be used for the calculation of the fouling factor. The devised model was tested for reliability and its accuracy in predicting new values for the fouling factor was greater than 98% in view of the design of the model Furthermore, the number of elements related to the design and operation was reduced to four developed formulae (developed factors) to which were added later the four factors selected as indicators of the occurrence of fouling. Both were then used as network input, whereas the output was the value of the fouling factor. The importance of this modelling lies in the fact that it enables the operator to continually predict the value of the fouling factor in heat exchangers and it assists him in taking appropriate measures to alleviate fouling effects ensuring thereby continuous operation of the unit and prevention of emergency shut downs.
A vision for permanents magnets PM standardisation activities continuous powder production.
The START project: Creating a
sustainable supply chain for green energy harvesting products by Powder Metallurgy
1. The CMIC / CanmetMINES Comminution Energy Recovery Potential Initiative
– The Agnico Eagle Goldex Division Case
*Jocelyn Bouchard1
, Gilles LeBlanc2
, Yan Germain3
, Michelle Levesque4
,
Nicolas Tremblay3
, Benjamin Légaré1
, Bernard Dallaire5
and Peter Radziszewski6
1
Université Laval, Département de génie des mines, de la métallurgie et des matériaux,
LOOP (Laboratoire d'observation et d'optimisation des procédés), Centre E4m,
Pavillon Adrien-Pouliot, 1065 avenue de la médecine, Québec, Québec, Canada, G1V 0A6
(*corresponding author: jocelyn.bouchard@gmn.ulaval.ca)
CanmetMINES / CanmetMINING
Ressources naturelles Canada / Natural Resources Canada
2
1 Promenade Haanel, Bâtiment 10, Ottawa, Ontario, Canada, K1A 1M1
3
1 Peter Ferderber Road, P.O. Box 1300, Val d'Or, Quebec, J9P 4P8
4
1079 Kelly Lake Road, Sudbury, Ontario, P3E 5P5
5
Agnico Eagle Mines – Division Goldex
1953 3e Avenue Ouest Val-d’Or, Québec, Canada, J9P 4N9
6
Metso Minerals Canada
795 Avenue George V, Lachine, Québec, Canada, H8S 2R9
ABSTRACT
The comminution process is estimated to be only 1% efficient, resulting in waste energy
dissipated as heat, noise, and vibration. Energy recovery from grinding circuits has not been implemented
mainly because recovering heat from the surface of the grinding mill or from mill slurry can impede
operation, increase maintenance requirements, and prolong plant shutdown time (and production).
However, currently very little information is available in the public domain regarding the amount of waste
energy and that potentially recoverable in the grinding circuit of a mineral processing plant. Availability of
such information could drive innovation and improve decision-making regarding opportunities for waste
energy recovery. The Canadian Mining Innovation Council (CMIC) has initiated a study with
CanmetMINING and mining industry partners to develop a model to map the energy flows in grinding
circuits and to quantify the potential for energy recovery. The paper outlines the underlying fundamentals
and data requirements for use in the model and then focuses on quantifying the energy recovery potential
of the semi-autogenous grinding and ball mill circuits at the Agnico Eagle Goldex Division. Results show
that most of the electrical energy (over 75%) is used to heat the slurry, leaving only a relatively small
amount of it to achieve mechanical work (~9%).
KEYWORDS
Comminution processes, Grinding mills, Energy recovery potential, Energy flow model
2. INTRODUCTION
CanmetMINING commissioned a study in 2013 to better understand the barriers for adoption of
new technologies in the mining industry (MNP, 2013). The conclusions highlighted the importance of
enhancing industry/regulator engagement and communication to raise awareness and improve the
industry’s comfort level with new technologies.
In November 2014, the Green Mining Innovation Advisory Committee (GMIAC) held a
workshop to explore the possibility of accelerating the uptake of green mining technologies by bringing
together key stakeholders among the mining value chain to address industry priorities. Participants
included representatives from mining companies and associations, academia, provincial governments and
federal departments and organizations. Two key priority areas emerged at the workshop: i) energy saving,
and ii) water management.
CanmetMINING committed to provide resources to conduct R&D in these areas, and to
collaborate with mining sector stakeholders to develop and deploy pilot projects. The Canada Mining
Innovation Council (CMIC) / CanmetMINING comminution energy recovery potential initiative emerged
from this commitment. The objectives are twofold, and consist of:
1) testing an innovative approach of conducting research that should result in accelerating the
development and deployment of green technologies by bringing together key stakeholders such as
mining companies, academia and manufacturers of grinding mills, and
2) accelerating the uptake of a modeling tool that identifies recoverable waste energy.
More specifically, the pilot project aims at developing a model to map the energy flows within
grinding circuits and to identify recoverable waste energy.
Grinding is largely recognised as a very inefficient process; energy efficiency estimates range
from <1 to 2 % (Fuerstenau and Abouzeid, 2002; Tromans and Meech, 2002, 2004) when comparing the
input energy to that required to generating new mineral surfaces. Criticising an “ill definition of the
reference for the output energy”, Fuerstenau and Abouzeid (2002) proposed to use the “energy for
producing new surface area by the compression loading or impact loading of single specimens” in order to
provide a “more meaningful baseline”. They concluded based on this reference that “the ball mill is
reasonably efficient energetically”, e.g. exhibiting an efficiency of ~15 % for quartz.
Schellinger and Lalkela (1951) and Schellinger (1951) defined thermodynamic efficiency as the
ratio of the effective work to the energy input. The effective work in the comminution process
corresponded to the difference between the energy input and that lost as heat and it was determined that the
thermodynamic efficiency of comminution ranged from 10 to 20%. Tromans (2008) introduced the
“relative efficiency ratio” involving the concept of “maximum ideal limiting efficiency” against which the
conventional energy efficiency is compared. Even using this definition, efficiency figures remain very low,
ranging from 3 to 26%.
There is therefore potential for improvement, and the following different approaches are currently
being examined by various researchers to tackle this issue, all of them aiming at reducing inefficiencies:
• exploiting comminution mechanisms exhibiting lower specific energy footprint, either with
the so-called “mine-to-mill” approach (i.e. consistent and fine blasting product)
(Kanchibotla, Valery, and Morrell, 1999), or taking advantage of compression-based
processing equipment (high pressure grinding rolls and crushers) (Morrell, 2009; Van Der
Meer and Gruendken, 2010);
• reducing the amount of material processed or reprocessed in grinding equipment using ore
sorting (Lessard, De Bakker, and McHugh, 2014), coarse particle processing (Awatey,
Skinner, and Zanin, 2015), flash separators (Tbaybi, 2015), or improved particle
classification (Silva, Vieira, Lobato, and Barrozo, 2012);
3. • optimising existing operations (e.g. maximising throughput) (Levesque and Millar, 2015) or
using process control capabilities to reduce specific energy consumption (Nunez,
MacPherson, Graffi, and Tuzun, 2009).
The concept put forward in this paper was introduced by Radziszewski (2013). It differs from the
aforementioned approaches in the sense that it considers recovering waste energy rather than reducing it.
Radziszewski (2013) estimated using a thermodynamic analysis that 43% of the energy input in a typical
mill is transferred to the slurry, raising the temperature of the discharge product. Some possibilities were
proposed to increase the recoverable heat captured by the slurry (e.g. insulation, sealing, raising slurry %
solids), and convert it to electricity, thus increasing the comminution efficiency to ~4% to ~11%,
depending on the scenario. In the most optimistic case (2-stage milling, 2,065 tph, insulated and sealed
equipment), energy savings translated to 7,3 GWh or 5 million CAD annually (at 0.20 $/kWh).
Radziszewski and Hewitt (2015) applied the same “thermodynamic comminution model” to
explore the amount of waste energy recoverable at Glencore’s Raglan Mine, a fly-in-fly-out operation in
Northern Quebec (Canada) using electricity mainly supplied by diesel power generators. The investigation
required a temperature measurement survey at the site. Results revealed that the potential recoverable
energy could increase from ~6% to ~17% in the ball mill circuit, and from ~3% to ~16% in the SAG
(semi-autogenous grinding) mill circuit with the implementation of measures to:
• reduce radiation and conduction/convection losses,
• reduce evaporation,
• increase the process water temperature, and
• reduce the temperature of the thermal fluid thermoelectric generator (to maximise heat
capture).
The annual value of the potential recoverable energy was estimated at ~0.7 million CAD for the
current baseline, and 2.5 million CAD if all the modifications were implemented.
This paper presents an MS Excel application to allow the identification of energy flows using the
thermodynamic comminution model suggested by Radziszewski (2013). A case study using data from
Agnico Eagle’s Goldex Division served to develop the model. Energy flows were mapped in the 2-stage
grinding circuit to characterise the individual heat losses, quantify the heat accumulated in the slurry and
determine how much could potentially be recovered. The first section reviews the fundamentals of
quantifying energy use and the potential for recovery in comminution circuits, and the second one provides
a brief overview of the proposed energy flow model. The remaining sections of the paper are dedicated to
present the results from a case study and to discuss their practical implications.
QUANTIFYING COMMINUTION ENERGY USE AND RECOVERY POTENTIAL
Characterising energy flows in a comminution circuit requires i) defining a control volume around
the relevant pieces of equipment, and ii) determining the input and output energy streams within this
control volume, as illustrated in Figure 1 where:
• 𝑚 represents a mass flowrate,
• ℎ represents the specific enthalpy,
• subscripts sl, air, in and out are used for slurry, air, inlet, and outlet streams respectively,
• 𝑊!"!# is the electrical power input,
• 𝑄!"#$ are the power losses dissipated as heat (evaporation, convection / radiation, dissipated
in mechanical and electrical components), and
• 𝑊!"#$ corresponds to the work output (creation of new surface, liners and grinding media
wear, plastic deformation, and mechanical losses).
The energy balance can be written around the control volume as
4. Figure 1 – Control volume around a grinding circuit
𝑊!"!# − 𝑊!"#$ − 𝑄!"#$ = 𝑚!" !"# ℎ!" !"# − 𝑚!" !" ℎ!" !" + 𝑚!"# !"# ℎ!"# !"# − 𝑚!"# !" ℎ!"# !" (1)
In equation (1), the term corresponding to 𝑊!"!# and those on the right hand side can all be
characterised from operation data, temperature measurements, and slurry composition.
Quantifying the Heat Losses
The power losses corresponding to 𝑄!"#$ can be broken down into 3 subcomponents:
1) heat dissipated in the electrical and mechanical components,
2) heat dissipated at the mill shell through convection/radiation,
3) latent energy absorbed by water during evaporation.
The main mechanical and electrical components typically installed in a grinding mill are the
transformer, variable speed drive (for mill speed modulation), electric motor, gearbox, mill trunnions and
oil cooling system. Power losses from a given component (𝑄!"#$ !"#$"%&%') are dissipated as heat and are
proportional to the power transferred to the equipment (𝑊!"#$"%&%') and its efficiency (𝜂!!"#!$%$&), i.e.
𝑄!"#$ !"#$"%&%' = 𝑊!"#$"%&%' 1 − 𝜂!"#$"%&%' (2)
The mechanical and electrical components used to power a grinding mill are commonly used in
industrial applications, thus technical data for these are available from manufacturers.
Figure 2 illustrates the energy losses from the equipment used to power a grinding mill. The
efficiency values stated on the figure correspond to those of the equipment installed at the Goldex Mill. All
values, except that for the trunnions, were obtained from manufacturers’ technical specifications. The
efficiency of the trunnions was calculated from historical data obtained from Goldex.
The remaining heat losses corresponding to convection, radiation and evaporation can be
estimated from equipment dimensions and operation data, providing a few simplifying assumptions as
demonstrated by Radziszewski and Hewitt (2015).
Quantifying the Work Output
Estimating the power output 𝑊!"#$ resulting from mechanical work performed inside the control
volume is more challenging. There are essentially four main sources of mechanical work:
˙W frag
˙W elec
˙Q lost
˙m air in h air in
˙m sl in h sl in
˙m air out h air out
˙m sl out h sl out
5. Figure 2 – Energy losses in electrical and mechanical components
1) ore comminution,
2) wear (grinding media and liners),
3) plastic deformation (grinding media and liners), and
4) vibration and noise.
The interpretation of the concept of mechanical work in a grinding system used in this paper
follows the one postulated by Schellinger (1952), i.e. it is “the disappearance of energy […] caused by the
creation of surface energy within the tumbling chamber”. In other words, it is the “energy absorption from
the tumbling system” calculated as a difference using equation (1): after quantifying 𝑊!"!#, 𝑄!"#$, and the
members on the right hand side, the only remaining unknown is 𝑊!"#$.
Elastic deformation work is entirely returned to the system as heat. This is not the case for plastic
deformations, which can store between 6 to 40 % of the mechanical work as internal constraints (Fekete
and Szekeres, 2015). The fraction of stored energy varies inversely with the rate of deformation. Assuming
that plastic deformations in a grinding mill would occur rapidly (impact mechanism), the fraction of stored
energy would be close to the lower bound, i.e. ~ 6 % of the mechanical deformation work. Moreover,
grinding media and steel liners typically don't undergo important plastic deformation. This suggests that
very little of the mill power draw is involved in mechanical deformation work. Nevertheless, the resulting
distribution, as a percentage of electrical input power is included in 𝑊!"#$.
Unlike other sources of mechanical work, energy dissipated as vibration and noise were quantified
in the case study using tri-axial accelerometers and sound intensity sensors. Vibration energy can be
estimated using three different calculation methods: i) the Hooke theory of elasticity, ii) instantaneous
power of a vibrating rigid body, and iii) statistical energy analysis flowing through a structure. Each of
these is based on a different model and requires analysing the frequency content of the collected data.
Sound intensity can be used to determine the sound power according to ISO-9614-2: 1996 and ISO-9614-
3: 2002 standards.
Input power used to perform mechanical work cannot be recovered. Thus the potential for energy
recovery corresponds to that within 𝑄!"#$ as well as that in the mass flows of the air and slurry streams.
6. ENERGY FLOW MODEL
The energy flow model was developed using MS Excel due to the widespread availability and
ease of use of this software. The model allows quantifying heat losses (mechanical, electrical, convection,
radiation, evaporation, and slurry) as well as work (comminution, wear, deformation, vibration and noise)
power losses, and the amount potentially recoverable.
The input parameters of the model consist of run-of-mine (ROM) ore mineral composition,
flowrates (ROM ore, water addition and lubricating oil), and temperatures (ROM ore, water, lubricating
oil, bearing, and discharged slurry). Solids fractions (mill fresh feed, mill discharge, hydrocyclone streams)
and mill parameters (dimensions, power draw, and speed) are also required for mapping the energy flows
in a grinding circuit. The measured values and those obtained from the PLC (programmable logic
controller) are used to quantify the various heat losses. The balance of the energy input is then allocated to
the work output since this share cannot be easily measured. The following section presents a case study
that was used during the development of the energy flow model.
CASE STUDY: AGNICO EAGLE GOLDEX DIVISION
Agnico Eagle Goldex Division is located in the city of Val-d'Or (North-western Quebec, Canada).
It is an underground mine extracting 5,100 t/d grading 1.5 g/t to produce 100,000 ounces of gold per year.
ROM ore feeds a 2-stage crushing circuit before entering the processing plant. An open-circuit SAG mill
(7.32 X 3.73 m effective grinding length, 3,357 kW) processes the product from the crushing stage. The
discharged slurry is further ground into a pre-classification closed-circuit ball mill (5.03 X 8.23 m effective
grinding length, 3,357 kW) to reduce the dimension of 80 % of the ore particles (P80) to ~100 µm.
The Goldex flowsheet stands out with the entire ball mill discharge feeding the gravity separation
circuit to recover about two thirds of the gold units. The gravity separation tails are reprocessed in the ball
mill circuit. The hydrocylone overflow (P80 of ~100 µm) is routed to the flotation circuit in which the
remaining gold is recovered in a gold-bearing pyrite concentrate. This concentrate is trucked to the
LaRonde processing plant (60 km west) where it is treated in a dedicated cyanide leaching circuit. Figure 3
depicts the grinding circuit of the Goldex Division flowsheet.
The control volume for each mill used in this case study is depicted in Figure 4, and shows the
following eight output heat flows:
Figure 3 – Agnico Eagle Goldex Division – grinding circuit
7. Figure 4 – Energy flow model
• power loss dissipated as heat in the transformer (𝑄!), variable frequency drive (𝑄!), electric
motor (𝑄!), gearbox (𝑄!), trunnion cooling system (𝑄!), convection and radiation around the
mill shell (𝑄!);
• enthalpy flows with air (𝑄!) and slurry (𝑄!) streams at the mill discharge.
To map the energy flows in the grinding circuit, measurements were taken to record mill feed
stream temperatures (ore and water), output slurry temperature and relative humidity at the inlet and outlet
of the SAG and ball mills. Several readings were recorded during a period of 5 days to gather data at
variable operating conditions. These were used in conjunction with the corresponding hourly values of
mass flowrates, power consumption, solids fraction, and trunnion oil flowrate and temperature obtained
from the PLC. The manufacturer’s equipment efficiency values were also used to quantify the heat losses
within the defined control volume.
The distribution of the power output as a percentage of the electrical power input is presented in
Figure 5 and Figure 6 for the SAG and ball mill respectively. It should be noted that the ball mill is not
equipped with a variable speed drive at this mineral processing operation, thus 𝑄! is omitted from Figure 6.
DISCUSSION
The information from the case study, presented in Figure 5 and Figure 6, revealed that most of the
power used is transferred to the enthalpy flows carried by the slurry streams, i.e. 68.9% and 81.9% for the
SAG and ball mill respectively, or 75.4% for the overall circuit. This was observed by an average
temperature increase between the feed and product streams of roughly 24°C in the SAG mill and 16°C in
the ball mill.
The most difficult value to measure corresponded to the SAG ore feed temperature. Sensors were
installed to record air temperature measurements in two locations: i) near the conveyor feeding the SAG
mill, and ii) in the dome where the ore is stored. It was estimated that these measurements could be used as
surrogate values for the ore temperature. However, readings using a laser temperature gun revealed that the
ore temperature values using this approach would be overestimated. Thus, the analysis was conducted by
using the outdoor temperature indexed by 6°C to account for the ore being warmer when extracted from
underground, even following the storage period.
In the SAG mill analysis, it can also be seen that the third largest share of power corresponds to
the heat used for water evaporation (8.3%). However, the evaporative heat loss in the ball mill was much
less at 1.2%. The difference between these was due to the smaller openings on the ball mill, which limit the
air draft. Evaporative losses were difficult to quantify and were estimated in both mills by assuming an
airflow velocity of 1.5 m/s and an estimate of the dimensions of the openings where air could escape.
Transformer
Variable
Frequency
Drive
Electric
Motor
Gearbox
˙Q 1
˙Q 2
˙Q 3
˙Q 4
˙Q 5
˙Q 6
˙Q 7
˙Q 8
˙W frag˙W elec
˙m sl in h sl in
˙m air in h air in
8. Figure 5 – Distribution of the power output in the SAG mill circuit
Figure 6 - Distribution of the power output in the ball mill circuit
Heat dissipated by
transformer, 2.0%
Heat dissipated by
variable frequency
drive, 2.0%
Heat dissipated by
electric motor, 2.9%
Heat dissipated by
gearbox, 2.3%
Heat dissipated by
trunnion cooling
system, 1.7%
Heat dissipated by
convection and
radiation, 0.6%
Heat transferred to air
by water evaporation,
8.3%
Heat transferred to the
slurry, 68.9%
Work output,
11.3%
Heat dissipated by
transformer, 2.0%
Heat dissipated by
electric motor, 2.9% Heat dissipated by
gearbox, 2.4% Heat dissipated by
trunnion cooling
system, 1.2%
Heat dissipated by
convection and
radiation, 1.0%
Heat transferred to air
by water evaporation,
1.2%
Heat transferred to the
slurry, 81.9%
Work
output,
7.4%
9. The heat losses from the equipment in both the SAG and ball mills, represented by 𝑄! to 𝑄!, were
comparable because their efficiencies and power ratings are similar. Heat losses by convection and
radiation (𝑄!) were also similar in both cases, but those for the ball mill were slightly higher because of its
larger surface area resulting in a higher convective heat transfer coefficient.
Once all the heat losses were quantified, the analysis showed that the power output attributed to
mechanical work, calculated as a difference, corresponds to 11.3% and 7.4% for the SAG and ball mills
respectively, or 9.3% for the overall circuit. These values are consistent with figures of 10 to 20% reported
by Schellinger and Lalkela (1951) and Schellinger (1951), which were determined using a similar
approach. This share included losses attributed to sound and vibration from the mills and screens, which
were determined negligible and corresponded to a total power of ~1.1 kW from measurements taken at the
Goldex mill.
Recovering and using some of the identified losses could improve the efficiency of the
comminution process. Assuming 95% mill availability, the total energy available as heat adds up to 23.8
GWh for the SAG mill, and 24.9 GWh for the ball mill annually. It must be emphasised though that
thermal losses through convection and radiation, as well as those from the electric motor, gearbox,
evaporation and trunnion cooling system are de facto recovered during the cold weather period of the year
as they contribute to heating the building. This is also true for a portion of the enthalpy conveyed by the
slurry in pump boxes and in downstream processing tanks. Moreover, even the heat contained in the slurry
exiting the plant is currently being used to some extent as it contributes at preventing tailings pipe to freeze
up during the winter. This is particularly important at Goldex as tailings are either pumped to the paste
backfill plant located 700 m west of the concentrator, or at the Manitou reclaiming site through a 24 km
long pipeline. Estimating the heat recovery potential must thus factor in that most of the energy is currently
being wasted only about 6 months per year, i.e. from May to November.
The question of finding a usage for the recoverable energy still requires to be addressed for the
remainder of year. In a cyanidation plant, a heat source is required all year round to preheat elution
solution. This is not an issue at Goldex since the gold/silver bearing concentrate is not processed onsite. If
other heat consumers cannot be identified, the only option is to convert heat into electricity.
CONCLUSION
This paper introduced the energy flow mapping application developed by CanmetMINING to
assess the energy recovery potential in grinding circuits. It is based on Radziszewski's thermodynamic
comminution model (Radziszewski, 2013), and was presented using data from Agnico Eagle’s Goldex
Division. Energy flows were mapped in the two-stage grinding circuit to show that
• 68.9% and 81.9% of the electrical power input is accumulated in the discharged slurry for the SAG
and ball mill respectively, and
• 11.3% and 7.4% of the supplied power performing actual mechanical work for the SAG and ball mills
respectively.
The total energy stored as heat represents 48.7 GWh annually, a portion of which is already used
for passive heating during the winter. A substantial amount of energy is potentially available for recovery
but it can only be useful if a demand for this energy is identified. Transforming the virtual recoverable
energy into an actual “supply” is beyond the scope of this study. Future work could examine various
strategies and technologies for low grade heat recovery, such as heat pumps, heat exchangers, and CO2
power generating turbines among others. Energy recovery solutions would require retrofits in existing
plants with the purchase and installation of heat transfer/conversion equipment, which may impact
operation, metal recovery and maintenance. Thus a techno-economic assessment would be required to
determine whether the options are financially viable for heat recovery in grinding circuits. Future efforts
should also aim to determine how design practices could be adapted for future mine sites to enable smart
energy management that could benefit from this energy resource.
10. ACKNOWLEDGEMENTS
The authors would like to thank Agnico Eagle Mines and CanmetMINING for granting
permission to publish this work. Further acknowledgements have to be given to Sam Marcuson (CMIC),
Carl Weatherell (CMIC), Nabil Bouzoubaâ (CanmetMINING) for championing this R&D initiative. A
special mention has to be given to Anthony Gérard and Pierre-Claude Ostiguy (SoftdB) for providing the
analysis estimating power losses through noise and vibration.
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