At medium to high gas content rates, the gas-liquid separation phenomenon and the stagnation behaviors of the gas masses occurring in the impeller channels are essential factors affecting the hydraulic performance of multiphase pumps. This paper designs a split trailing edge flap suitable for the multiphase pump to improve the hydraulic performance in the impeller by varying the flap deflection angle and length. The model’s reliability was assessed by comparing the experimental outcome with the external characteristics of the experimental data. Based on the Eulerian-Eulerian multiphase model and the SST k‐ω turbulence model, the effects of different flap lengths on external characteristics, the turbulent kinetic energy and pressure distribution are analyzed. The study results show that when the length of the separated trailing edge flap is 0.25 l 0 and the deflection angle is 5°, the transporting efficiency of the multiphase pump is the highest at IGVF=50% with an efficiency increase of 3.40% compared to the original model. Its optimal flap length scheme effectively reduces the radial pressure gradient and the inverse pressure gradient in the impeller channel, which suppresses the gas blockage phenomenon to a certain extent.
在中高含气量条件下，叶轮流道内的气液分离现象和气团的滞留行为是影响多相泵水力性能的重要因素。本文设计了一种适用于多相泵的分体式尾缘襟翼，通过改变襟翼的偏转角度和长度来提高叶轮内的水力性能。通过比较实验结果与实验数据的外部特征来评估模型的可靠性。基于欧拉-欧拉多相模型和SST k ω湍流模型，分析了不同襟翼长度对外部特性、湍流动能和压力分布的影响。研究结果表明，当分离尾缘襟翼长度为0.25 l 0，偏转角为5°时，在IGVF=50%时多相泵的输送效率最高，效率比原模型提高了3.40%。其优化的襟翼长度方案有效地减小了叶轮通道内径向压力梯度和逆压力梯度，在一定程度上抑制了气阻现象。
{"title":"Influence of trailing edge flap length and deflection angle on the performance of the multiphase pump","authors":"Wei Han, Juping Zhou, Rennian Li, Xiaoning Ma, None HaojieWang","doi":"10.1177/09576509231211395","DOIUrl":"https://doi.org/10.1177/09576509231211395","url":null,"abstract":"At medium to high gas content rates, the gas-liquid separation phenomenon and the stagnation behaviors of the gas masses occurring in the impeller channels are essential factors affecting the hydraulic performance of multiphase pumps. This paper designs a split trailing edge flap suitable for the multiphase pump to improve the hydraulic performance in the impeller by varying the flap deflection angle and length. The model’s reliability was assessed by comparing the experimental outcome with the external characteristics of the experimental data. Based on the Eulerian-Eulerian multiphase model and the SST k‐ω turbulence model, the effects of different flap lengths on external characteristics, the turbulent kinetic energy and pressure distribution are analyzed. The study results show that when the length of the separated trailing edge flap is 0.25 l 0 and the deflection angle is 5°, the transporting efficiency of the multiphase pump is the highest at IGVF=50% with an efficiency increase of 3.40% compared to the original model. Its optimal flap length scheme effectively reduces the radial pressure gradient and the inverse pressure gradient in the impeller channel, which suppresses the gas blockage phenomenon to a certain extent.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135818387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-31DOI: 10.1177/09576509231212245
Gargee Pise, Milankumar Nandgaonkar
Loop heat pipe (LHP) encased in phase change material (PCM) incorporated annular to catalytic converter (CC) is proposed to augment the performance of the “thermal energy storage” (TES). LHP are designed to extract surplus heat from the exhaust discharge, thereby reducing the amount of exhaust heat emitted into the atmosphere. A four-cylinder IC engine’s CC is considered with Mg 70 Zn 24.9 Al 5.1 , paraffin oil as PCM and working fluid for the heat pipe are evaluated. A comparative experimental investigation was performed considering two models for CC with and without heat pipe integrated in the TES for (i) distribution of average PCM temperature (ii) energy, exergy efficiency and distribution (iii) effectiveness (iv) instantaneous waste heat recovered during heat storage. Transient cycles at 2000 r/min with varying load conditions were run considering city drive conditions. Heat storage for CC with heat pipe encased in TES was found to be 35% faster, whereas discharge time for CC without heat pipe developed in TES was found to be longer. For melt fraction 1, maximum exergy efficiencies of 71% and 69% were observed for the TES unit with and without heat pipe. Heat pipes are observed to help extract a considerable amount of surplus heat from exhaust and reduce the exhaust gas outlet temperature released into the atmosphere by nearly 130 – 40°C under various load circumstances.
为了提高“热能储存”(TES)的性能，提出了一种采用相变材料(PCM)包裹的环形热管(LHP)，并结合了环形催化转化器(CC)。LHP的设计目的是从废气排放中提取余热，从而减少排放到大气中的废热量。以mg70 Zn 24.9 Al 5.1，石蜡油为PCM，热管工质为工质，对某四缸内燃机的CC进行了评价。对比实验研究考虑了在TES中集成热管和不集成热管的两种CC模型(i) PCM平均温度分布(ii)能量、能源效率和分布(iii)有效性(iv)蓄热过程中回收的瞬时余热。考虑城市驱动条件，以2000 r/min的速度运行了不同负载条件下的瞬态循环。发现在TES中装有热管的CC的储热速度快35%，而在TES中没有开发热管的CC的放电时间更长。对于熔体分数1，有热管和没有热管的TES装置的最大火用效率分别为71%和69%。观察到热管有助于从排气中提取相当数量的余热，并在各种负载情况下将排放到大气中的排气出口温度降低近130 - 40°C。
{"title":"Energy and exergy analysis of latent heat storage with heat pipe encased in phase change material","authors":"Gargee Pise, Milankumar Nandgaonkar","doi":"10.1177/09576509231212245","DOIUrl":"https://doi.org/10.1177/09576509231212245","url":null,"abstract":"Loop heat pipe (LHP) encased in phase change material (PCM) incorporated annular to catalytic converter (CC) is proposed to augment the performance of the “thermal energy storage” (TES). LHP are designed to extract surplus heat from the exhaust discharge, thereby reducing the amount of exhaust heat emitted into the atmosphere. A four-cylinder IC engine’s CC is considered with Mg 70 Zn 24.9 Al 5.1 , paraffin oil as PCM and working fluid for the heat pipe are evaluated. A comparative experimental investigation was performed considering two models for CC with and without heat pipe integrated in the TES for (i) distribution of average PCM temperature (ii) energy, exergy efficiency and distribution (iii) effectiveness (iv) instantaneous waste heat recovered during heat storage. Transient cycles at 2000 r/min with varying load conditions were run considering city drive conditions. Heat storage for CC with heat pipe encased in TES was found to be 35% faster, whereas discharge time for CC without heat pipe developed in TES was found to be longer. For melt fraction 1, maximum exergy efficiencies of 71% and 69% were observed for the TES unit with and without heat pipe. Heat pipes are observed to help extract a considerable amount of surplus heat from exhaust and reduce the exhaust gas outlet temperature released into the atmosphere by nearly 130 – 40°C under various load circumstances.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135814142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.1177/09576509231211756
Xiangting Sun, Zhuoxiong Zeng, Ruibing Wu
To investigate the impact of different vortex structure on the combustion stability in a chamber, this paper evaluates the performance of a vortex combustion chamber coupled with a swirler and a guide ring. The simulated cases include different guide ring angles of 95°, 105°, 115°, 125° and 135°, in addition to a control case without coupling the guide ring. The distributions of velocity, vorticity, temperature, outlet temperature distribution factor ( OTDF), reaction rate, turbulent kinetic energy ( k), synergy angle ( β), and NO emission are numerically analyzed. Results show that the coupling of the swirler and guide ring changes the vortex structure and significantly influences the chamber performance. The increase of the guide ring angles ( α) enhances the interaction between the swirl flow and the direct jet, which intensifies heat and mass transfer, as well as turbulence. The application of the guide ring induces external entrainment of the jet, leading to the formation of a large central recirculation zone compared to that without a guide ring. With increasing the α from 95° to 135°, both average outlet velocity and tangential velocity ( V t ) at the coaxial line position decrease, while the flame length decreases by 286 mm. And the OTDF variation among all cases is less than 0.065. The β of the central section decreases from 76.18° to 70.17°. Furthermore, combustion chamber without the guide ring exhibits higher temperature and OTDF.
{"title":"Analysis of vortex combustion flow in a chamber o<u>f</u> guide ring coupling with swirl flow","authors":"Xiangting Sun, Zhuoxiong Zeng, Ruibing Wu","doi":"10.1177/09576509231211756","DOIUrl":"https://doi.org/10.1177/09576509231211756","url":null,"abstract":"To investigate the impact of different vortex structure on the combustion stability in a chamber, this paper evaluates the performance of a vortex combustion chamber coupled with a swirler and a guide ring. The simulated cases include different guide ring angles of 95°, 105°, 115°, 125° and 135°, in addition to a control case without coupling the guide ring. The distributions of velocity, vorticity, temperature, outlet temperature distribution factor ( OTDF), reaction rate, turbulent kinetic energy ( k), synergy angle ( β), and NO emission are numerically analyzed. Results show that the coupling of the swirler and guide ring changes the vortex structure and significantly influences the chamber performance. The increase of the guide ring angles ( α) enhances the interaction between the swirl flow and the direct jet, which intensifies heat and mass transfer, as well as turbulence. The application of the guide ring induces external entrainment of the jet, leading to the formation of a large central recirculation zone compared to that without a guide ring. With increasing the α from 95° to 135°, both average outlet velocity and tangential velocity ( V t ) at the coaxial line position decrease, while the flame length decreases by 286 mm. And the OTDF variation among all cases is less than 0.065. The β of the central section decreases from 76.18° to 70.17°. Furthermore, combustion chamber without the guide ring exhibits higher temperature and OTDF.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136104763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-28DOI: 10.1177/09576509231209003
James W Lazenby, Eugene Shwageraus, Alexander J White
The paper provides thermodynamic analysis of an energy storage concept in which thermal stores are coupled with the feedwater heating train of nuclear-powered steam plant. This allows the electrical output of the plant to be flexed whilst maintaining constant reactor power, thereby providing the equivalent of an electricity storage system and facilitating the adoption of a load-following role for nuclear plant. The concept falls under the umbrella of ‘generation-integrated energy storage’, which exploits existing hardware required for generation to reduce storage costs, and benefits also from fewer energy transformations when compared to ‘electricity-in-electricity-out’ forms of storage. This means that a high (effective) round-trip efficiency can be achieved at low cost. An important feature of the proposed system is that the turbine bleed flows (at their various pressures and temperatures) automatically provide good thermal matching with the feedwater temperature profile, so that heat can ultimately be transferred to and from sensible-heat thermal-storage media with high exergetic efficiency. Various options are discussed for the thermal stores, including pressurised water tanks, thermal oils and packed beds. The analysis also includes consideration of the off-design behaviour of cycle components.
{"title":"A feedheat-integrated energy storage system for nuclear-powered steam plant","authors":"James W Lazenby, Eugene Shwageraus, Alexander J White","doi":"10.1177/09576509231209003","DOIUrl":"https://doi.org/10.1177/09576509231209003","url":null,"abstract":"The paper provides thermodynamic analysis of an energy storage concept in which thermal stores are coupled with the feedwater heating train of nuclear-powered steam plant. This allows the electrical output of the plant to be flexed whilst maintaining constant reactor power, thereby providing the equivalent of an electricity storage system and facilitating the adoption of a load-following role for nuclear plant. The concept falls under the umbrella of ‘generation-integrated energy storage’, which exploits existing hardware required for generation to reduce storage costs, and benefits also from fewer energy transformations when compared to ‘electricity-in-electricity-out’ forms of storage. This means that a high (effective) round-trip efficiency can be achieved at low cost. An important feature of the proposed system is that the turbine bleed flows (at their various pressures and temperatures) automatically provide good thermal matching with the feedwater temperature profile, so that heat can ultimately be transferred to and from sensible-heat thermal-storage media with high exergetic efficiency. Various options are discussed for the thermal stores, including pressurised water tanks, thermal oils and packed beds. The analysis also includes consideration of the off-design behaviour of cycle components.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136159413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-18DOI: 10.1177/09576509231208815
Mehmet ali Kallioğlu, Ali Serkan Avcı, Ahmet Yılmaz, Hakan Karakaya
This study empirically examines the effectiveness of the solar chimney power plants (SCPP), which is an innovative method for the use of solar energy, in the middle latitude region (37.88° N) in the northern hemisphere. Experimental measurement parameters of temperature, velocity, and radiation obtained from four cardinal directions (north, south, east, and west) and from 26 different locations were recorded throughout the day (08:00 am-07:30 pm). These measurements were used to calculate and estimate the power values used to measure the energy efficiency of the solar chimney. In the study, the genetic programming method was used to estimate the power value. In the five different forecast models developed, 15 different parameters were used diagonally. The obtained power estimation equations were cross-checked using statistical methods. Determination coefficient value is higher than >0.90 in all equations and is close to the ideal. In the comparison of all statistical models, the Global Performance Indicator (GPI) was used, with the best result obtained from Model 2. The results of this model are MAPE:6.5233, MBE: −0.0124, RMSE:1.1036 ve t-stat:0.0374, which is quite close to zero. In addition, the power values obtained from both the calculated and developed models were dimensioned and compared over the power-time factor of eight different studies in the literature. The mean relative error value nof the values calculated as a result of this comparison varies between 2.3% and 21.3%. This study provides a model for the different geometries of solar chimney prototypes and provides an example for measuring the design and performance of solar chimney systems to be installed in the middle latitudes and in regions with “Csa” climate characteristics, and is recommended for academic and industrial users. The mathematical models developed can be considered as a step to increase the efficiency of the solar chimney power plants.
{"title":"A genetic programming approach for the prediction of solar chimney power plant power","authors":"Mehmet ali Kallioğlu, Ali Serkan Avcı, Ahmet Yılmaz, Hakan Karakaya","doi":"10.1177/09576509231208815","DOIUrl":"https://doi.org/10.1177/09576509231208815","url":null,"abstract":"This study empirically examines the effectiveness of the solar chimney power plants (SCPP), which is an innovative method for the use of solar energy, in the middle latitude region (37.88° N) in the northern hemisphere. Experimental measurement parameters of temperature, velocity, and radiation obtained from four cardinal directions (north, south, east, and west) and from 26 different locations were recorded throughout the day (08:00 am-07:30 pm). These measurements were used to calculate and estimate the power values used to measure the energy efficiency of the solar chimney. In the study, the genetic programming method was used to estimate the power value. In the five different forecast models developed, 15 different parameters were used diagonally. The obtained power estimation equations were cross-checked using statistical methods. Determination coefficient value is higher than >0.90 in all equations and is close to the ideal. In the comparison of all statistical models, the Global Performance Indicator (GPI) was used, with the best result obtained from Model 2. The results of this model are MAPE:6.5233, MBE: −0.0124, RMSE:1.1036 ve t-stat:0.0374, which is quite close to zero. In addition, the power values obtained from both the calculated and developed models were dimensioned and compared over the power-time factor of eight different studies in the literature. The mean relative error value nof the values calculated as a result of this comparison varies between 2.3% and 21.3%. This study provides a model for the different geometries of solar chimney prototypes and provides an example for measuring the design and performance of solar chimney systems to be installed in the middle latitudes and in regions with “Csa” climate characteristics, and is recommended for academic and industrial users. The mathematical models developed can be considered as a step to increase the efficiency of the solar chimney power plants.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135825479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-18DOI: 10.1177/09576509231207154
Suraj Choudhary, Vikash Kumar, Varun Singhal
Considering the higher outlet temperature, the present study assessed the performance of Zinc oxide (ZnO) and Magnesium oxide (MgO) nanofluid-based flat plate solar collector at a low volumetric flow rate, that is, 30 L/h. The lower solar irradiance results in a low percentage enhancement in collector efficiency; therefore, it constraints the use of the nanofluid-based collector at such conditions. The collector efficiency was nearly 67.98% and 65.22% for 1 vol% ZnO and 0.2 vol% MgO, respectively, almost 20.57% and 16.53% more than base fluid (ethylene glycol: distilled water). For 1 vol% ZnO and 0.2 vol% MgO, the heat absorption parameter intensified by 20.48% and 17.12%, respectively. The payback period at the optimum concentrations of ZnO and MgO nanofluid-based flat plate solar collector compared to electric heating was ∼2.97 and 3.69 years, respectively. In terms of present worth, the cost savings in a life span of 15 years was approximately 1918.18 and 1839.05 USD for 1 vol% ZnO and 0.2 vol% MgO, respectively. Such gains could be extended using large-sized areas of collectors. The 1 vol% ZnO at the flow rate of 30 L/h has the shortest payback period and highest cost-saving; hence, profoundly recommended in the flat plate solar collector instead of the base fluid.
{"title":"Thermal performance and economic sustainability of flat plate solar collectors using MgO and ZnO nanofluids: A comparative analysis","authors":"Suraj Choudhary, Vikash Kumar, Varun Singhal","doi":"10.1177/09576509231207154","DOIUrl":"https://doi.org/10.1177/09576509231207154","url":null,"abstract":"Considering the higher outlet temperature, the present study assessed the performance of Zinc oxide (ZnO) and Magnesium oxide (MgO) nanofluid-based flat plate solar collector at a low volumetric flow rate, that is, 30 L/h. The lower solar irradiance results in a low percentage enhancement in collector efficiency; therefore, it constraints the use of the nanofluid-based collector at such conditions. The collector efficiency was nearly 67.98% and 65.22% for 1 vol% ZnO and 0.2 vol% MgO, respectively, almost 20.57% and 16.53% more than base fluid (ethylene glycol: distilled water). For 1 vol% ZnO and 0.2 vol% MgO, the heat absorption parameter intensified by 20.48% and 17.12%, respectively. The payback period at the optimum concentrations of ZnO and MgO nanofluid-based flat plate solar collector compared to electric heating was ∼2.97 and 3.69 years, respectively. In terms of present worth, the cost savings in a life span of 15 years was approximately 1918.18 and 1839.05 USD for 1 vol% ZnO and 0.2 vol% MgO, respectively. Such gains could be extended using large-sized areas of collectors. The 1 vol% ZnO at the flow rate of 30 L/h has the shortest payback period and highest cost-saving; hence, profoundly recommended in the flat plate solar collector instead of the base fluid.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135825105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The efficiency of Darrieus wind turbines has increased significantly due to developments in blade design, albeit at the expense of the simplicity provided by simple straight blades. The purpose of this research is to gain insight into the influence of various curvatures embedded in the plan of the blade while maintaining its simple straight shape. A variation in chord length along the span defines the curvature. To assess their effect on performance and efficiency, concave, and convex Leading-Trailing Edged Blades (LTEB) are investigated and evaluated in comparison to straight blades. That is viable to gain valuable insight about these blade designs' potential advantages in various applications by studying their aerodynamic characteristics and flow characteristics. The Q-blade tool is used to simulate 3D unsteady Nonlinear Lifting Lines Free Vortex Wake (3D-NLLFVW). The virtual camber effect brought on by flow curvatures is implemented to improve the results' accuracy. According to the findings, H-Darrieus' aerodynamic efficiency climbed by 16% and 9.5% at high TSR. For the concave and convex LTEBs, the torque ripple is smoothed by 37% and 19%, respectively. Additionally, compared to the straight-bladed rotor, the chosen variations enable volume reductions of 53% and 28%.
{"title":"Numerical investigation on the spanwise chord distribution effects on the performance of an H-darrieus vertical axis wind turbines","authors":"Khaled Souaissa, Moncef Ghiss, Hatem Bentaher, Mouldi Chrigui, Aref Maalej","doi":"10.1177/09576509231205483","DOIUrl":"https://doi.org/10.1177/09576509231205483","url":null,"abstract":"The efficiency of Darrieus wind turbines has increased significantly due to developments in blade design, albeit at the expense of the simplicity provided by simple straight blades. The purpose of this research is to gain insight into the influence of various curvatures embedded in the plan of the blade while maintaining its simple straight shape. A variation in chord length along the span defines the curvature. To assess their effect on performance and efficiency, concave, and convex Leading-Trailing Edged Blades (LTEB) are investigated and evaluated in comparison to straight blades. That is viable to gain valuable insight about these blade designs' potential advantages in various applications by studying their aerodynamic characteristics and flow characteristics. The Q-blade tool is used to simulate 3D unsteady Nonlinear Lifting Lines Free Vortex Wake (3D-NLLFVW). The virtual camber effect brought on by flow curvatures is implemented to improve the results' accuracy. According to the findings, H-Darrieus' aerodynamic efficiency climbed by 16% and 9.5% at high TSR. For the concave and convex LTEBs, the torque ripple is smoothed by 37% and 19%, respectively. Additionally, compared to the straight-bladed rotor, the chosen variations enable volume reductions of 53% and 28%.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135854829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the energy crisis and environmental deterioration, the emerging hybrid energy ship power system gradually replaced the traditional ship power system to keep environmental friendliness by employing the clean energy. However, the increase of energy storage and photovoltaic generation system brings enormous challenge to the optimization scheduling of hybrid energy ship power system. For this reason, an improved genetic algorithm-based optimal scheduling strategy for the hybrid energy ship power system is developed in this paper. Firstly, a novel hybrid energy ship power system model including the diesel generator, energy storage system, propulsion system, dynamic load and photovoltaic power generation device is constructed under the constraint of energy efficiency and greenhouse gases emissions. Considering the various navigation situations that the ship may encounter, such as photovoltaic power generation limit in extreme weather and diesel generator power change in load shedding, the corresponding scheduling optimization problems for the hybrid energy ship power system are established. Under the cost and gas emission constraints, an improved genetic algorithm-based scheduling optimization algorithm is proposed. By introducing the nonlinear parameter change model in crossover and mutation operator, the performance of improved genetic algorithm can be enhanced, such as convergence speed and global optimization ability. Compared with current works, the proposed scheduling optimization strategy can achieve the lowest cost while reducing environmental impacts. Finally, simulation results under the given navigation cases demonstrate the superiority of the proposed improved genetic algorithm-based scheduling optimization strategy.
{"title":"An energy dispatch optimization for hybrid power ship system based on improved genetic algorithm","authors":"Xinyu Wang, Hongyu Zhu, Xiaoyuan Luo, Shaoping Chang, Xinping Guan","doi":"10.1177/09576509231205342","DOIUrl":"https://doi.org/10.1177/09576509231205342","url":null,"abstract":"Due to the energy crisis and environmental deterioration, the emerging hybrid energy ship power system gradually replaced the traditional ship power system to keep environmental friendliness by employing the clean energy. However, the increase of energy storage and photovoltaic generation system brings enormous challenge to the optimization scheduling of hybrid energy ship power system. For this reason, an improved genetic algorithm-based optimal scheduling strategy for the hybrid energy ship power system is developed in this paper. Firstly, a novel hybrid energy ship power system model including the diesel generator, energy storage system, propulsion system, dynamic load and photovoltaic power generation device is constructed under the constraint of energy efficiency and greenhouse gases emissions. Considering the various navigation situations that the ship may encounter, such as photovoltaic power generation limit in extreme weather and diesel generator power change in load shedding, the corresponding scheduling optimization problems for the hybrid energy ship power system are established. Under the cost and gas emission constraints, an improved genetic algorithm-based scheduling optimization algorithm is proposed. By introducing the nonlinear parameter change model in crossover and mutation operator, the performance of improved genetic algorithm can be enhanced, such as convergence speed and global optimization ability. Compared with current works, the proposed scheduling optimization strategy can achieve the lowest cost while reducing environmental impacts. Finally, simulation results under the given navigation cases demonstrate the superiority of the proposed improved genetic algorithm-based scheduling optimization strategy.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135303664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-03DOI: 10.1177/09576509231205346
Bai Li, Guangyuan Mu, Lei Luo, Wei Du, Xun Zhou
A numerical investigation is conducted to explore the potential of combined slot suction in controlling the shock wave and flow separation in a transonic compressor cascade. The three slots in the combined scheme are arranged in different directions on the suction surface and endwall. The locations are determined by the shock wave and separation point in the baseline cascade. Based on these locations, two combined schemes and three single schemes are provided to explore the control mechanism. For each suction scheme, five bleed mass ratios are examined at the same inlet Mach number. The results suggested that the cascade throughflow loss could be decreased by three single schemes. However, the cascade performance is improved slightly or even deteriorated when the losses generated by the suction are considered. The key reasons are the local effects of single scheme and the opposite trend between corner stall and the suction surface separation. Both corner stall and the suction surface separation are eliminated by the combined scheme with two slots, and the maximum reduction in throughflow losses is 75%. The new corner separation evolved from the horseshoe vortex limited the performance of combined scheme. When the bleed mass ratio excided 5%, the combined scheme with three slots is better than the two slots scheme in loss control. The reason is the improved endwall boundary layer and the eliminated new corner separation. By inducing the horseshoe vortex into the slot, the interaction of the two endwall slots eliminates the new corner separation.
{"title":"Effect of combined boundary layer suction on the separation control in a highly loaded transonic compressor cascade","authors":"Bai Li, Guangyuan Mu, Lei Luo, Wei Du, Xun Zhou","doi":"10.1177/09576509231205346","DOIUrl":"https://doi.org/10.1177/09576509231205346","url":null,"abstract":"A numerical investigation is conducted to explore the potential of combined slot suction in controlling the shock wave and flow separation in a transonic compressor cascade. The three slots in the combined scheme are arranged in different directions on the suction surface and endwall. The locations are determined by the shock wave and separation point in the baseline cascade. Based on these locations, two combined schemes and three single schemes are provided to explore the control mechanism. For each suction scheme, five bleed mass ratios are examined at the same inlet Mach number. The results suggested that the cascade throughflow loss could be decreased by three single schemes. However, the cascade performance is improved slightly or even deteriorated when the losses generated by the suction are considered. The key reasons are the local effects of single scheme and the opposite trend between corner stall and the suction surface separation. Both corner stall and the suction surface separation are eliminated by the combined scheme with two slots, and the maximum reduction in throughflow losses is 75%. The new corner separation evolved from the horseshoe vortex limited the performance of combined scheme. When the bleed mass ratio excided 5%, the combined scheme with three slots is better than the two slots scheme in loss control. The reason is the improved endwall boundary layer and the eliminated new corner separation. By inducing the horseshoe vortex into the slot, the interaction of the two endwall slots eliminates the new corner separation.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135697449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-30DOI: 10.1177/09576509231203068
Yiğit Gülmez
This study investigated the negative impact of exhaust back-pressure (EBP) on diesel engine performance and how it can be mitigated by advancing fuel injection timing (FIT). Experiments were conducted on a diesel engine with various EBP and FIT settings, and the impact of these factors on engine performance was evaluated under a constant load. The results showed that increasing EBP delayed the combustion process, resulted in longer ignition delay periods, and decreased engine efficiency. However, by advancing FIT, these negative effects could be mitigated to some extent. Specifically, advancing FIT led to shorter ignition delay periods, improved combustion rate, and earlier maximum pressure values. The study highlights the potential of controlling FIT as a promising approach to reduce the negative impact of EBP on diesel engine performance and environmental impact. The results of the study have practical implications for diesel engine operators seeking to offset the negative impact of EBP resulting from the integration of waste heat recovery or aftertreatment systems in the exhaust system, which is aimed at improving the efficiency and reducing the environmental footprint of diesel engines.
{"title":"The role of advancing fuel injection timing in mitigating the negative impact of exhaust back-pressure on diesel engines’ performance","authors":"Yiğit Gülmez","doi":"10.1177/09576509231203068","DOIUrl":"https://doi.org/10.1177/09576509231203068","url":null,"abstract":"This study investigated the negative impact of exhaust back-pressure (EBP) on diesel engine performance and how it can be mitigated by advancing fuel injection timing (FIT). Experiments were conducted on a diesel engine with various EBP and FIT settings, and the impact of these factors on engine performance was evaluated under a constant load. The results showed that increasing EBP delayed the combustion process, resulted in longer ignition delay periods, and decreased engine efficiency. However, by advancing FIT, these negative effects could be mitigated to some extent. Specifically, advancing FIT led to shorter ignition delay periods, improved combustion rate, and earlier maximum pressure values. The study highlights the potential of controlling FIT as a promising approach to reduce the negative impact of EBP on diesel engine performance and environmental impact. The results of the study have practical implications for diesel engine operators seeking to offset the negative impact of EBP resulting from the integration of waste heat recovery or aftertreatment systems in the exhaust system, which is aimed at improving the efficiency and reducing the environmental footprint of diesel engines.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136336467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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