Pub Date : 2021-05-24DOI: 10.11648/J.AJEE.20210902.12
Hao-Hsiang Liu, Guowei Zheng, Man Changzhong, Ke Jiang, Xiaogang Lv
Numerical simulations and experiments are carried out in this paper to research about characteristics of heat transfer, frictional resistance and comprehensive performance of turbulent water flow (3000 < Re < 10,000) in a circular tube with twisted tape inserts. A new type of twisted tape is proposed and it shows excellent performance on heat transfer enhancement. Effects of three parameters including twist ratio (p/w=3, 4, 5), geometrical structure of alternation of clockwise and counterclockwise, existence of semicircular cuts are researched in simulations. The results show that lower twist ratio and the geometrical structure of alternation of clockwise and counterclockwise can enhance heat transfer while the existence of semicircular cuts can significantly reduce flow resistance. Experiments are conducted to validate the actual effect of the twisted tapes and the experimental results are basically consistent with the simulation results. Nusselt number and friction factor with the new type of twisted tape inserts are respectively 1.66-2.42 times and 4.36-4.97 times to that of plain tube while the maximum value of PEC (performance evaluation criteria) reaches 1.42 in experiments. The results of simulations and experiments indicate that the new type of twisted tape has a distinct advantage on heat transfer enhancement. Verification between simulations and experiments are carried out. The result shows that all deviations of corresponding values between simulations and experiments are within 15%, which reflects that the numerical predications are basically in agreement with the experiment results. Finally, a comparative analysis was carried out with the new type of twisted tape in this paper and the different twisted tapes in the previous research. The new type of twisted tape proposed in this paper has higher Nusselt number and friction coefficient.
本文通过数值模拟和实验研究了3000 < Re < 10000的湍流水流在带扭带插入的圆管内的传热特性、摩擦阻力及综合性能。提出了一种新型的扭曲带，它具有优良的强化传热性能。仿真研究了扭力比(p/w= 3,4,5)、顺、逆时针交替的几何结构、存在半圆切口等3个参数的影响。结果表明，较低的扭比和顺、逆时针交替的几何结构可以增强换热，而半圆切口的存在可以显著降低流动阻力。通过实验验证了扭曲带的实际效果，实验结果与仿真结果基本一致。新型扭带插入件的努塞尔数和摩擦系数分别是普通管的1.66 ~ 2.42倍和4.36 ~ 4.97倍，实验中PEC(性能评价标准)最大值达到1.42。仿真和实验结果表明，新型扭带在强化传热方面具有明显的优势。仿真与实验结果进行了对比验证。结果表明，模拟值与实验值的偏差均在15%以内，说明数值预测与实验结果基本一致。最后，将本文设计的新型扭带与前人研究的不同扭带进行了对比分析。本文提出的新型扭带具有较高的努塞尔数和摩擦系数。
{"title":"Numerical and Experimental Studies on Heat Transfer Enhancement in a Circular Tube Inserted with Twisted Tape Inserts","authors":"Hao-Hsiang Liu, Guowei Zheng, Man Changzhong, Ke Jiang, Xiaogang Lv","doi":"10.11648/J.AJEE.20210902.12","DOIUrl":"https://doi.org/10.11648/J.AJEE.20210902.12","url":null,"abstract":"Numerical simulations and experiments are carried out in this paper to research about characteristics of heat transfer, frictional resistance and comprehensive performance of turbulent water flow (3000 < Re < 10,000) in a circular tube with twisted tape inserts. A new type of twisted tape is proposed and it shows excellent performance on heat transfer enhancement. Effects of three parameters including twist ratio (p/w=3, 4, 5), geometrical structure of alternation of clockwise and counterclockwise, existence of semicircular cuts are researched in simulations. The results show that lower twist ratio and the geometrical structure of alternation of clockwise and counterclockwise can enhance heat transfer while the existence of semicircular cuts can significantly reduce flow resistance. Experiments are conducted to validate the actual effect of the twisted tapes and the experimental results are basically consistent with the simulation results. Nusselt number and friction factor with the new type of twisted tape inserts are respectively 1.66-2.42 times and 4.36-4.97 times to that of plain tube while the maximum value of PEC (performance evaluation criteria) reaches 1.42 in experiments. The results of simulations and experiments indicate that the new type of twisted tape has a distinct advantage on heat transfer enhancement. Verification between simulations and experiments are carried out. The result shows that all deviations of corresponding values between simulations and experiments are within 15%, which reflects that the numerical predications are basically in agreement with the experiment results. Finally, a comparative analysis was carried out with the new type of twisted tape in this paper and the different twisted tapes in the previous research. The new type of twisted tape proposed in this paper has higher Nusselt number and friction coefficient.","PeriodicalId":326389,"journal":{"name":"American Journal of Energy Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129869437","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}
Pub Date : 2021-05-24DOI: 10.11648/J.AJEE.20210902.13
Si-Hong Xie, Yongquan Hu, Wang Xiaojin, Wu Shaowei, L. Cheng, Yuan Hui
Highly-deviated well are applied for effectively developing WCH9 gas field with deep buried and low permeability, and the payzone are candidates for hydraulic fracturing by evaluation of gas reservoir. Therefore, fracture initiation pressure is a key parameter for design of hydraulic fracturing treatment. Firstly, a series of experiments were completed by core sample from target formation, Young's modulus is about 13GPa and Poisson's ratio is 0.286 at a confining pressure of 40MPa, horizontal principal stress is 78 MPa and 63 MPa, and in-situ stress profiles were interpreted by logging data. Then, the formation rock is regarded as isotropic linear elastic material, thus total stresses distribution on the deviated wellbore wall was determined by stress superposition principle, in which in-situ stress redistribution around the deviated wellbore, fluid pressure acted on the borehole wall and filtration stress are taken into account when fracturing fluid was injected into wellbore. Further, prediction model of fracture initiation pressure was established by applying criterion of maximum tensile stress and effective stress transformation. Lastly, according to the borehole trajectory, in-situ stress and other parameters from payzone of WCH9 block, fracturing initiation pressure varied with Deviation angle and azimuth angle were computed by numerical simulation method, these results provide a basis for optimization design of hydraulic fracturing technology parameters.
{"title":"Research on Fracture Initiation Pressure in Deviated Well of WCH9 Block","authors":"Si-Hong Xie, Yongquan Hu, Wang Xiaojin, Wu Shaowei, L. Cheng, Yuan Hui","doi":"10.11648/J.AJEE.20210902.13","DOIUrl":"https://doi.org/10.11648/J.AJEE.20210902.13","url":null,"abstract":"Highly-deviated well are applied for effectively developing WCH9 gas field with deep buried and low permeability, and the payzone are candidates for hydraulic fracturing by evaluation of gas reservoir. Therefore, fracture initiation pressure is a key parameter for design of hydraulic fracturing treatment. Firstly, a series of experiments were completed by core sample from target formation, Young's modulus is about 13GPa and Poisson's ratio is 0.286 at a confining pressure of 40MPa, horizontal principal stress is 78 MPa and 63 MPa, and in-situ stress profiles were interpreted by logging data. Then, the formation rock is regarded as isotropic linear elastic material, thus total stresses distribution on the deviated wellbore wall was determined by stress superposition principle, in which in-situ stress redistribution around the deviated wellbore, fluid pressure acted on the borehole wall and filtration stress are taken into account when fracturing fluid was injected into wellbore. Further, prediction model of fracture initiation pressure was established by applying criterion of maximum tensile stress and effective stress transformation. Lastly, according to the borehole trajectory, in-situ stress and other parameters from payzone of WCH9 block, fracturing initiation pressure varied with Deviation angle and azimuth angle were computed by numerical simulation method, these results provide a basis for optimization design of hydraulic fracturing technology parameters.","PeriodicalId":326389,"journal":{"name":"American Journal of Energy Engineering","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115212586","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}
Pub Date : 2021-04-29DOI: 10.11648/J.AJEE.20210902.11
Susan Andrew Mbacho, T. Thoruwa, N. Lang’at, E. Ako
The use of solar energy in drying of perishable crops such as tomatoes is a good alternative to the problem of post-harvest processing in tropical eastern African countries. A review of the literature revealed that most of the solar crop drying systems developed during the last five decades have small loading capacity and cannot operate during the night. Therefore, an integrated solar greenhouse dryer system [SGDS] with Clay-CaCl2 desiccant energy storage system was designed and tested. Such SGDS have the advantage over other solar systems of high loading capacity and structural simplicity. In addition, they have relatively good thermal crop drying performance compared to most solar dryers. However, their main limitation, like most solar dryers, is their inability to dry at night. Therefore, to enhance night-time drying capacity, a prototype SGDS integrated with a low-cost Clay-CaCl2 desiccant energy storage system was designed, fabricated, and tested. The drying performance of this prototype was evaluated using loads of fresh tomatoes during October – December 2019 at Nairobi, Kenya. The dryer was able to dry fresh tomatoes from 93.9% (mcwb) to 8.3% (mcwb) within 27hours with solar greenhouse drying efficiency of 23% during daytime and desiccant drying efficiency of 19.9% during nighttime. The drying rate for the two-day light drying was 0.985kg/h and 0.875kg/h respectively and that in night drying using desiccants was 0.34kg/h. Based on these results, it was concluded that prototype solar greenhouse dryer with Clay-CaCl₂ energy storage has great potential for drying perishable produce such as tomatoes in tropical countries.
{"title":"Performance of an Integrated Solar-Greenhouse Photovoltaic Ventilated Dryer with Clay-CaCl2 Energy Storage Desiccants for Tomato Drying","authors":"Susan Andrew Mbacho, T. Thoruwa, N. Lang’at, E. Ako","doi":"10.11648/J.AJEE.20210902.11","DOIUrl":"https://doi.org/10.11648/J.AJEE.20210902.11","url":null,"abstract":"The use of solar energy in drying of perishable crops such as tomatoes is a good alternative to the problem of post-harvest processing in tropical eastern African countries. A review of the literature revealed that most of the solar crop drying systems developed during the last five decades have small loading capacity and cannot operate during the night. Therefore, an integrated solar greenhouse dryer system [SGDS] with Clay-CaCl2 desiccant energy storage system was designed and tested. Such SGDS have the advantage over other solar systems of high loading capacity and structural simplicity. In addition, they have relatively good thermal crop drying performance compared to most solar dryers. However, their main limitation, like most solar dryers, is their inability to dry at night. Therefore, to enhance night-time drying capacity, a prototype SGDS integrated with a low-cost Clay-CaCl2 desiccant energy storage system was designed, fabricated, and tested. The drying performance of this prototype was evaluated using loads of fresh tomatoes during October – December 2019 at Nairobi, Kenya. The dryer was able to dry fresh tomatoes from 93.9% (mcwb) to 8.3% (mcwb) within 27hours with solar greenhouse drying efficiency of 23% during daytime and desiccant drying efficiency of 19.9% during nighttime. The drying rate for the two-day light drying was 0.985kg/h and 0.875kg/h respectively and that in night drying using desiccants was 0.34kg/h. Based on these results, it was concluded that prototype solar greenhouse dryer with Clay-CaCl₂ energy storage has great potential for drying perishable produce such as tomatoes in tropical countries.","PeriodicalId":326389,"journal":{"name":"American Journal of Energy Engineering","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117213311","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}
Pub Date : 2021-03-26DOI: 10.11648/J.AJEE.20210901.12
E. Khartukov
Current and past statuses and dynamics of oil production and methods of oil measurements in different countries – under different temperatures and preassures – are considered and analyzed. The author uses methods of comparative and systematic analyses, which are implemented for assessing oil production in the USA, Saudi Arabia and Russia – the world’s leading oil producers – and globally (in the world’s context) in the past, currently and in the foreseeable future (throughout 2050). Crude oil and field (crude + lease NGLs) are considered. Oil developments in the USA, Saudi Arabia and Russia are analyzed separately with their main oil fields being covered. In the past a status of the world’s largest oil producer was taken in rotation by Russia and Saudi Arabia. Before 1992 the world supremacy in oil belonged to Russia but afterwards and until 2014 – mainly to Saudi Arabia. The article mainly concludes that now (since 2014) the USA produce more oil (crude oil + field condensate) than any other country of the world, even without accounting for indigenous biofuel liquids and mostly thanks to the massive tight-oil production.
{"title":"Which Country Is the Largest Oil Producer in the World – the USA, Russia or Saudi Arabia: The Question of Measurement – What and How","authors":"E. Khartukov","doi":"10.11648/J.AJEE.20210901.12","DOIUrl":"https://doi.org/10.11648/J.AJEE.20210901.12","url":null,"abstract":"Current and past statuses and dynamics of oil production and methods of oil measurements in different countries – under different temperatures and preassures – are considered and analyzed. The author uses methods of comparative and systematic analyses, which are implemented for assessing oil production in the USA, Saudi Arabia and Russia – the world’s leading oil producers – and globally (in the world’s context) in the past, currently and in the foreseeable future (throughout 2050). Crude oil and field (crude + lease NGLs) are considered. Oil developments in the USA, Saudi Arabia and Russia are analyzed separately with their main oil fields being covered. In the past a status of the world’s largest oil producer was taken in rotation by Russia and Saudi Arabia. Before 1992 the world supremacy in oil belonged to Russia but afterwards and until 2014 – mainly to Saudi Arabia. The article mainly concludes that now (since 2014) the USA produce more oil (crude oil + field condensate) than any other country of the world, even without accounting for indigenous biofuel liquids and mostly thanks to the massive tight-oil production.","PeriodicalId":326389,"journal":{"name":"American Journal of Energy Engineering","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130957310","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}
Pub Date : 2019-12-05DOI: 10.11648/J.AJEE.20190704.11
Djimako Bongo, A. M. Nanimina, Edith Kadjangaba, J. Champagne
The purpose of this study is to determine the phase indicator functions (vacuum rate, velocity and bubble size) of the gas-liquid flow. The gas-liquid flows in these columns (aquarium) are intrinsically unstable and the dynamics of such flows influence the mixing and mass transfer performance. It is therefore important to characterize the dynamics of gas-liquid flow. Also, the complete knowledge of the global dynamics of the fluids of the bubble column is based on that of the bubble. The experimental analysis is carried out using a two-phase instrumentation consisting of an optical fiber bi-probe. The use of the experimental techniques has enabled a better understanding of the hydrodynamics of two-phase flow. In terms of results, intrusive techniques provide local measurements while non-intrusive techniques provide a distribution over a cross-section with different spatial and temporal resolutions. The optical fiber bi-probe placed between two column flanges permit to have a complete mapping of the dispersed phase flow. The use of a mass flow meter and an ultrasonic flow meter, in different flow configurations, made it possible to obtain data on the operation of the column. However, the analysis of granulometry of the bubbles in the columns is performed by intrusive, flow-disrupting and non-intrusive techniques. Knowledge of bubble size and vacuum rate is crucial for determining interfacial air.
{"title":"Experimental Study of Hydrodynamics in the Aquarium Using PIV Method","authors":"Djimako Bongo, A. M. Nanimina, Edith Kadjangaba, J. Champagne","doi":"10.11648/J.AJEE.20190704.11","DOIUrl":"https://doi.org/10.11648/J.AJEE.20190704.11","url":null,"abstract":"The purpose of this study is to determine the phase indicator functions (vacuum rate, velocity and bubble size) of the gas-liquid flow. The gas-liquid flows in these columns (aquarium) are intrinsically unstable and the dynamics of such flows influence the mixing and mass transfer performance. It is therefore important to characterize the dynamics of gas-liquid flow. Also, the complete knowledge of the global dynamics of the fluids of the bubble column is based on that of the bubble. The experimental analysis is carried out using a two-phase instrumentation consisting of an optical fiber bi-probe. The use of the experimental techniques has enabled a better understanding of the hydrodynamics of two-phase flow. In terms of results, intrusive techniques provide local measurements while non-intrusive techniques provide a distribution over a cross-section with different spatial and temporal resolutions. The optical fiber bi-probe placed between two column flanges permit to have a complete mapping of the dispersed phase flow. The use of a mass flow meter and an ultrasonic flow meter, in different flow configurations, made it possible to obtain data on the operation of the column. However, the analysis of granulometry of the bubbles in the columns is performed by intrusive, flow-disrupting and non-intrusive techniques. Knowledge of bubble size and vacuum rate is crucial for determining interfacial air.","PeriodicalId":326389,"journal":{"name":"American Journal of Energy Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129520402","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}
Pub Date : 2019-11-11DOI: 10.11648/j.ajee.20190703.12
T. Wanjekeche, Theophilus Ananias
Stand-alone microgrid hold a primary solution for electricity and water supply in remote areas access to National grid is not possible. This paper presents a detailed optimal sizing and economic evaluations of a stand-alone microgrid for a remote village (Amarika) in Namibia. Several renewable energy sources such as wind turbines and photovoltaic arrays were considered with a battery backup storage system and a reverse osmosis desalination plant for water supply. Modelling of the microgrid was done based on the meteorological data, the daily water and energy demand of the village. Particle swarm optimization was employed for the system techno- economic optimization: to determine a suitable microgrid configuration that can be established at minimum cost. Sensitivity analysis of the system was performed to examine the effect of variation of LPSP on LCOE. The results demonstrate that the optimized microgrid configuration and the optimization algorithm are effective and can be adopted in supplying power and water to the village. The levelized cost of electricity proves the economic feasibility of the microgrid. The levelized cost of electricity falls within a 90% standard deviation (σ=0.065) of the mean. This proved to be economically feasible with a 96.5% reliability of power supply.
{"title":"Optimal and Economic Evaluation of a Stand-alone Microgrid for Electricity and Water Supply for Namibia’s Rural Village","authors":"T. Wanjekeche, Theophilus Ananias","doi":"10.11648/j.ajee.20190703.12","DOIUrl":"https://doi.org/10.11648/j.ajee.20190703.12","url":null,"abstract":"Stand-alone microgrid hold a primary solution for electricity and water supply in remote areas access to National grid is not possible. This paper presents a detailed optimal sizing and economic evaluations of a stand-alone microgrid for a remote village (Amarika) in Namibia. Several renewable energy sources such as wind turbines and photovoltaic arrays were considered with a battery backup storage system and a reverse osmosis desalination plant for water supply. Modelling of the microgrid was done based on the meteorological data, the daily water and energy demand of the village. Particle swarm optimization was employed for the system techno- economic optimization: to determine a suitable microgrid configuration that can be established at minimum cost. Sensitivity analysis of the system was performed to examine the effect of variation of LPSP on LCOE. The results demonstrate that the optimized microgrid configuration and the optimization algorithm are effective and can be adopted in supplying power and water to the village. The levelized cost of electricity proves the economic feasibility of the microgrid. The levelized cost of electricity falls within a 90% standard deviation (σ=0.065) of the mean. This proved to be economically feasible with a 96.5% reliability of power supply.","PeriodicalId":326389,"journal":{"name":"American Journal of Energy Engineering","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122217595","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}
Pub Date : 2019-10-21DOI: 10.11648/j.ajee.20190703.11
L. O. Ebale, L. Gomat, Nzonzolo, Marc Romaric Mavoungou, Feldha Kibongani
The use of the Peltier effect for the cooling of a cooler powered by photovoltaic energy is a solution for the conservation of foodstuffs or pharmaceuticals when conditions as well geographical and climatic become difficult. Only a problem often arises with the choice of the supply current. Indeed, a choice of the supply current too low will produce less cold while a choice of too much supply current (very close to the maximum value indicated by the manufacturer of the module) will produce more cold, but the module will work in saturation, which will reduce its life. This article proposes to present the possibility of optimizing a thermoelectric refrigeration installation. In particular: by improving the performances of the installation, by maximizing the coefficient of performance and the cooling capacity as a function of the power supply current of the Peltier effect module (of the TEC1-12706 type). Thus, to solve this problem, we propose an optimization of the thermoelectric installation while passing by the method of the derivatives which will make it possible to find this optimal current. This optimal current will be average current corresponding to the performance coefficient and the current for which the refrigeration power becomes maximum.
{"title":"Optimization of a Thermoelectric Cooling System with Peltier Effect","authors":"L. O. Ebale, L. Gomat, Nzonzolo, Marc Romaric Mavoungou, Feldha Kibongani","doi":"10.11648/j.ajee.20190703.11","DOIUrl":"https://doi.org/10.11648/j.ajee.20190703.11","url":null,"abstract":"The use of the Peltier effect for the cooling of a cooler powered by photovoltaic energy is a solution for the conservation of foodstuffs or pharmaceuticals when conditions as well geographical and climatic become difficult. Only a problem often arises with the choice of the supply current. Indeed, a choice of the supply current too low will produce less cold while a choice of too much supply current (very close to the maximum value indicated by the manufacturer of the module) will produce more cold, but the module will work in saturation, which will reduce its life. This article proposes to present the possibility of optimizing a thermoelectric refrigeration installation. In particular: by improving the performances of the installation, by maximizing the coefficient of performance and the cooling capacity as a function of the power supply current of the Peltier effect module (of the TEC1-12706 type). Thus, to solve this problem, we propose an optimization of the thermoelectric installation while passing by the method of the derivatives which will make it possible to find this optimal current. This optimal current will be average current corresponding to the performance coefficient and the current for which the refrigeration power becomes maximum.","PeriodicalId":326389,"journal":{"name":"American Journal of Energy Engineering","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133151589","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}
Pub Date : 2019-07-10DOI: 10.11648/J.AJEE.20190702.12
Chunhua Qiu, S. Ge, Ting Yang, J. Wei, Guoxing Xiang
Nowadays, the energy structure is gradually changing to clean power generation. Clean energy mainly includes renewable energy and part of non-renewable energy. Non-renewable energy is depleting day by day, showing a shrinking trend. Renewable energy is not affected by energy shortage, and is the focus of future development. How to ensure the sustainable and healthy development of clean energy, it is necessary to adjust the existing power generation energy structure scientifically and rationally. In this paper, the theory of hypergraph is introduced to cluster the optimal combination information of clean energy, and a hypergraph model of power generation energy structure adjustment is established. The problem of replacing fossil energy in power generation energy consumption with clean energy is solved as the original objective. By mapping the generation energy structure adjustment with hypergraph, the problem of generation energy structure adjustment is transformed into the problem of solving hypergraph path. By using the two-point hyperpath algorithm, an optimal path for the development of clean power generation, reducing the proportion of fossil energy power generation, and gradually converting to clean energy is obtained. The application of hypergraph algorithm in the structural adjustment of power generation is of great significance to promote the diversification of power generation energy, especially in the clean development, low-carbon development and green development of the power industry.
{"title":"Research on Power Generation Energy Sources Structure Adjustment Algorithm Based on HyperGraph","authors":"Chunhua Qiu, S. Ge, Ting Yang, J. Wei, Guoxing Xiang","doi":"10.11648/J.AJEE.20190702.12","DOIUrl":"https://doi.org/10.11648/J.AJEE.20190702.12","url":null,"abstract":"Nowadays, the energy structure is gradually changing to clean power generation. Clean energy mainly includes renewable energy and part of non-renewable energy. Non-renewable energy is depleting day by day, showing a shrinking trend. Renewable energy is not affected by energy shortage, and is the focus of future development. How to ensure the sustainable and healthy development of clean energy, it is necessary to adjust the existing power generation energy structure scientifically and rationally. In this paper, the theory of hypergraph is introduced to cluster the optimal combination information of clean energy, and a hypergraph model of power generation energy structure adjustment is established. The problem of replacing fossil energy in power generation energy consumption with clean energy is solved as the original objective. By mapping the generation energy structure adjustment with hypergraph, the problem of generation energy structure adjustment is transformed into the problem of solving hypergraph path. By using the two-point hyperpath algorithm, an optimal path for the development of clean power generation, reducing the proportion of fossil energy power generation, and gradually converting to clean energy is obtained. The application of hypergraph algorithm in the structural adjustment of power generation is of great significance to promote the diversification of power generation energy, especially in the clean development, low-carbon development and green development of the power industry.","PeriodicalId":326389,"journal":{"name":"American Journal of Energy Engineering","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134330554","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}
Pub Date : 2019-07-02DOI: 10.11648/J.AJEE.20190702.11
Gashaw Getenet, Yirgalem Damtew
Use of micro hydropower plants is an ideal method of providing power for off-grid rural communities especially in developing countries like Ethiopia. In Ethiopia only 8% of the rural community has access to electricity, and the power supply in the country is very low as compared to its population growth. The present study assesses the technical and socio economic aspect of water mill sites in North Shoa zone of Amhara regional state, Ethiopia for the development of micro hydro power plant. Through technical assessment of the flow rate measurement, head measurement and estimation of power generation potential of the mill sites has been done. The socio economic assessment was done by interviewing households, officials and mill owners. The results of the assessment shows that, out of the 14 mill sites investigated, 12 of them has the potential to generate power ranging from 5.52kw to 38.59kw with 80% efficiency during the dry season. It has been observed, the existing as well as former mill sites in North Shoa zone, are mostly located in the mountainous regions which offers an interesting opportunity for micro hydropower generation that would meet the energy demand of the villages at least 5km far from the main grid.
{"title":"Technical and Socio Economic Assessment of Water Mill Sites for Micro Hydro Power Generation in North Shoa Zone of Amhara Region","authors":"Gashaw Getenet, Yirgalem Damtew","doi":"10.11648/J.AJEE.20190702.11","DOIUrl":"https://doi.org/10.11648/J.AJEE.20190702.11","url":null,"abstract":"Use of micro hydropower plants is an ideal method of providing power for off-grid rural communities especially in developing countries like Ethiopia. In Ethiopia only 8% of the rural community has access to electricity, and the power supply in the country is very low as compared to its population growth. The present study assesses the technical and socio economic aspect of water mill sites in North Shoa zone of Amhara regional state, Ethiopia for the development of micro hydro power plant. Through technical assessment of the flow rate measurement, head measurement and estimation of power generation potential of the mill sites has been done. The socio economic assessment was done by interviewing households, officials and mill owners. The results of the assessment shows that, out of the 14 mill sites investigated, 12 of them has the potential to generate power ranging from 5.52kw to 38.59kw with 80% efficiency during the dry season. It has been observed, the existing as well as former mill sites in North Shoa zone, are mostly located in the mountainous regions which offers an interesting opportunity for micro hydropower generation that would meet the energy demand of the villages at least 5km far from the main grid.","PeriodicalId":326389,"journal":{"name":"American Journal of Energy Engineering","volume":"55 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132893409","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}
Pub Date : 2019-06-15DOI: 10.11648/J.AJEE.20190701.15
Zheng Huang, Yingjun Xie, F. Yin, Wudi Zhang, J. Liu
Cassava and corn are the two main ingredients in the process of producing fuel ethanol. This paper is mainly based on experiments. In this experiment, the traditional ethanol fermentation with cassava and corn as raw materials was compared with the the industrial ethanol fermentation with the same raw material, and the technological parameters of ethanol fermentation in traditional ethanol fermentation and industrial ethanol fermentation were compared and studied. The traditional double enzyme method was used for ethanol fermentation. Liquefaction temperature (70 plus or minus 1)°C, Saccharification temperature (60 plus or minus 1)°C, Fermentation temperature (30 plus or minus 1)°C. Experimental results show that: The average alcoholic production rate of corn was 36.64% and the average alcoholic production rate of cassava was 42.46% in the traditional ethanol fermentation, the average alcoholic production rate of corn was 38.22% and the average alcoholic production rate of cassava was 44.76% in the industrial ethanol fermentation. The industrial ethanol fermentation experiment is better than the traditional ethanol fermentation by comparison, because the former has better sealed anaerobic environment and greater capacity. It is suitable for large-scale production parameter study, in order to obtain higher utilization rate of raw materials, it shows a higher rate of alcohol production.
{"title":"Study on Technological Parameters of Pilot Production of Ethanol","authors":"Zheng Huang, Yingjun Xie, F. Yin, Wudi Zhang, J. Liu","doi":"10.11648/J.AJEE.20190701.15","DOIUrl":"https://doi.org/10.11648/J.AJEE.20190701.15","url":null,"abstract":"Cassava and corn are the two main ingredients in the process of producing fuel ethanol. This paper is mainly based on experiments. In this experiment, the traditional ethanol fermentation with cassava and corn as raw materials was compared with the the industrial ethanol fermentation with the same raw material, and the technological parameters of ethanol fermentation in traditional ethanol fermentation and industrial ethanol fermentation were compared and studied. The traditional double enzyme method was used for ethanol fermentation. Liquefaction temperature (70 plus or minus 1)°C, Saccharification temperature (60 plus or minus 1)°C, Fermentation temperature (30 plus or minus 1)°C. Experimental results show that: The average alcoholic production rate of corn was 36.64% and the average alcoholic production rate of cassava was 42.46% in the traditional ethanol fermentation, the average alcoholic production rate of corn was 38.22% and the average alcoholic production rate of cassava was 44.76% in the industrial ethanol fermentation. The industrial ethanol fermentation experiment is better than the traditional ethanol fermentation by comparison, because the former has better sealed anaerobic environment and greater capacity. It is suitable for large-scale production parameter study, in order to obtain higher utilization rate of raw materials, it shows a higher rate of alcohol production.","PeriodicalId":326389,"journal":{"name":"American Journal of Energy Engineering","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123868457","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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