Refrigeration technology contributes to 10∼15% of global energy consumption, resulting in significant carbon emission. Solar-driven ejection-compression refrigeration system is promising for reducing electricity consumption and carbon emissions. However, existing solar ejection-compression refrigeration systems suffer from drawbacks of low heat utilization efficiency, oversized solar collectors, and thermal leakage due to large temperature differences of storage devices. Addressing these challenges, this study proposes and investigates a new solar-assisted ejector-compressor hybrid refrigeration system with subcooling storage coupled at intermediate temperatures. The system model is established, and the ejector model is experimentally validated. Through system modelling, an energetic and exergetic performance comparative analyses are conducted. The results indicate that the COP of the proposed system is 9.7% higher than that of traditional system combinations, producing the same cooling capacity with the same generating heat. Moreover, considering the stored cooling energy can be fully converted to cooling energy at evaporating temperatures, the COPh of the new system reaches 8.29, 24.5% higher than traditional systems. The cooling storage at 15°C with 0.325 ejector entrainment ratio suggests a reduction of approximately two-thirds in energy storage, lower temperature differences, and reduced thermal leakage, leading to decreased space and economic costs and improved energy performance. Additionally, as the COPh, COPgh, and ηex of MCS mode consistently outperform those of ZCS and HCS modes, the MCS mode is prioritized in system operation. This study underscores that the new system offers superior overall energy efficiency and requires smaller storage devices compared to traditional systems, revealing its promising practical applications.
{"title":"Performance evaluation and comparative study on a novel solar-heat-driven ejection-compression hybrid cooling system with subcooling storage","authors":"Yingjie Xu, Yongjun Ling, Zhiwei Wang, Yaobo Zheng, Zhe Sun, Xiaopo Wang","doi":"10.1177/09576509241272788","DOIUrl":"https://doi.org/10.1177/09576509241272788","url":null,"abstract":"Refrigeration technology contributes to 10∼15% of global energy consumption, resulting in significant carbon emission. Solar-driven ejection-compression refrigeration system is promising for reducing electricity consumption and carbon emissions. However, existing solar ejection-compression refrigeration systems suffer from drawbacks of low heat utilization efficiency, oversized solar collectors, and thermal leakage due to large temperature differences of storage devices. Addressing these challenges, this study proposes and investigates a new solar-assisted ejector-compressor hybrid refrigeration system with subcooling storage coupled at intermediate temperatures. The system model is established, and the ejector model is experimentally validated. Through system modelling, an energetic and exergetic performance comparative analyses are conducted. The results indicate that the COP of the proposed system is 9.7% higher than that of traditional system combinations, producing the same cooling capacity with the same generating heat. Moreover, considering the stored cooling energy can be fully converted to cooling energy at evaporating temperatures, the COP<jats:sub>h</jats:sub> of the new system reaches 8.29, 24.5% higher than traditional systems. The cooling storage at 15°C with 0.325 ejector entrainment ratio suggests a reduction of approximately two-thirds in energy storage, lower temperature differences, and reduced thermal leakage, leading to decreased space and economic costs and improved energy performance. Additionally, as the COP<jats:sub>h</jats:sub>, COP<jats:sub>gh</jats:sub>, and η<jats:sub>ex</jats:sub> of MCS mode consistently outperform those of ZCS and HCS modes, the MCS mode is prioritized in system operation. This study underscores that the new system offers superior overall energy efficiency and requires smaller storage devices compared to traditional systems, revealing its promising practical applications.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945126","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 : 2024-08-02DOI: 10.1177/09576509241270837
Ping Liu, Shiming Sang, Lianghong Hu, Guangfeng Liu, Weihua Wang
Nanofluid was frequent technique which solved microscale heat and mass transport problems to intensify pool boiling heat transfer. This paper had investigated the effect of nanofluid, ultrasonic field and ribs surfaces on cooperative heat transfer enhancement in pool boiling. A two-step method was applied to prepare Al2O3 nanofluids of different kinds of concentrations and diameters. Group experiments were examined the influences of nanofluid concentration and diameter, ultrasonic power and distance and rib surface type on heat transfer characteristics, respectively. The heat flux and convection heat transfer coefficient were used the performance parameters. The results showed that the concentration and diameter of the Al2O3 nanofluid effected the heat transfer performance on the pool boiling. The Al2O3 nanofluid with an average diameter of 80 nm had the most significant enhancement effect on the pool boiling heat transfer performance, but the Al2O3 with a diameter of 30 nm had the weakest enhancement effect, when the concentration of Al2O3 nanofluid was 0.01 wt%. Meanwhile, the generated acoustic streaming effect and cavitation effect by ultrasonic field can promote the energy accumulation, rupture and regeneration of the bubbles at low superheat stage on nanofluid pool boiling. The heat transfer coefficient (HTC) gradually enhances as the ultrasonic field changes. At an ultrasonic power of 528 W and a distance of 50 mm, the nanofluid pool boiling increased by 44.34% compared to no ultrasonic field HTC. Compared with No rib, the boiling point of the Al2O3 nanofluidic pool boiling of Rib II was reduced by 2°C under the ultrasonic field. The nanofluid pool boiling with ultrasonic field of p = 528 W and Rib II had the best heat transfer effect, and HTC improved more than 50%. This is due to the addition of more nucleation points for bubbles on the heated surface of the Rib II.
纳米流体是解决微尺度传热和传质问题以强化池沸腾传热的常用技术。本文研究了纳米流体、超声波场和肋片表面对池水沸腾传热协同强化的影响。采用两步法制备了不同浓度和直径的 Al2O3 纳米流体。分组实验分别考察了纳米流体浓度和直径、超声功率和距离以及肋片表面类型对传热特性的影响。热通量和对流传热系数是性能参数。结果表明，Al2O3 纳米流体的浓度和直径对池沸腾的传热性能有影响。当 Al2O3 纳米流体的浓度为 0.01 wt% 时，平均直径为 80 nm 的 Al2O3 纳米流体对水池沸腾传热性能的增强效果最显著，而直径为 30 nm 的 Al2O3 纳米流体的增强效果最弱。同时，超声波场产生的声流效应和空化效应可促进纳米流体池沸腾低过热阶段气泡的能量积累、破裂和再生。传热系数（HTC）随着超声场的变化而逐渐增大。在超声波功率为 528 W、距离为 50 mm 时，纳米流体池沸腾比无超声波场 HTC 提高了 44.34%。与无肋相比，肋 II 的 Al2O3 纳米流体池沸点在超声场下降低了 2°C。超声波场 p = 528 W 和肋骨 II 的纳米流体池沸腾的传热效果最好，HTC 提高了 50%以上。这是因为在 Rib II 的受热表面上增加了更多的气泡成核点。
{"title":"Effect of ultrasonic field on pool boiling heat transfer to Al2O3 nanofluid on ribbed surfaces","authors":"Ping Liu, Shiming Sang, Lianghong Hu, Guangfeng Liu, Weihua Wang","doi":"10.1177/09576509241270837","DOIUrl":"https://doi.org/10.1177/09576509241270837","url":null,"abstract":"Nanofluid was frequent technique which solved microscale heat and mass transport problems to intensify pool boiling heat transfer. This paper had investigated the effect of nanofluid, ultrasonic field and ribs surfaces on cooperative heat transfer enhancement in pool boiling. A two-step method was applied to prepare Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> nanofluids of different kinds of concentrations and diameters. Group experiments were examined the influences of nanofluid concentration and diameter, ultrasonic power and distance and rib surface type on heat transfer characteristics, respectively. The heat flux and convection heat transfer coefficient were used the performance parameters. The results showed that the concentration and diameter of the Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> nanofluid effected the heat transfer performance on the pool boiling. The Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> nanofluid with an average diameter of 80 nm had the most significant enhancement effect on the pool boiling heat transfer performance, but the Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> with a diameter of 30 nm had the weakest enhancement effect, when the concentration of Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> nanofluid was 0.01 wt%. Meanwhile, the generated acoustic streaming effect and cavitation effect by ultrasonic field can promote the energy accumulation, rupture and regeneration of the bubbles at low superheat stage on nanofluid pool boiling. The heat transfer coefficient (HTC) gradually enhances as the ultrasonic field changes. At an ultrasonic power of 528 W and a distance of 50 mm, the nanofluid pool boiling increased by 44.34% compared to no ultrasonic field HTC. Compared with No rib, the boiling point of the Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> nanofluidic pool boiling of Rib II was reduced by 2°C under the ultrasonic field. The nanofluid pool boiling with ultrasonic field of p = 528 W and Rib II had the best heat transfer effect, and HTC improved more than 50%. This is due to the addition of more nucleation points for bubbles on the heated surface of the Rib II.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141881646","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 blades of an axial fan are optimized using artificial neural networks and genetic algorithms in this paper. In first, a parametric axial fan blade model is established with constraints imposed on several parameters. The chord length, maximum camber, maximum camber position, blade thickness, and airfoil stagger angle are considered as an optimization parameter of axial fan. The static pressure efficiency and static pressure of axial fan are regarded as the optimization objectives. An optimization calculation of an axial fan blade is carried out based on the combination of artificial neural network and genetic algorithm. The objective aim of optimization is to improve the static pressure efficiency, the static pressure of axial fan and to reduce the flow loss of axial fan. Numerical results of axial fan demonstrate that the pressure distribution gradient and turbulent kinetic energy contour maps of the optimized axial fan are effectively suppressed within the impeller region compared with that of original axial fan. Furthermore, the internal flow stability of the optimized axial fan also is significantly improved by studying the pressure fluctuation and the Fast Fourier Transform (FFT) of pressure fluctuation. Experimental results of axial fan aerodynamic performance further demonstrate that the static pressure of the optimized axial fan rises as much as 90.93 Pa and the improved static pressure efficiency is effectively improved as much as 7.43% at the design flow rates compared with that of the original axial fan. The application of optimized axial flow fans is of great significance in energy-saving of energy equipment.
{"title":"Aerodynamic performance and flow optimization of axial fan based on the neural network and genetic algorithm","authors":"Tianyi Sun, Xiaoming Wu, Kejun Mao, Zhengdao Wang, Hui Yang, Yikun Wei","doi":"10.1177/09576509241267857","DOIUrl":"https://doi.org/10.1177/09576509241267857","url":null,"abstract":"The blades of an axial fan are optimized using artificial neural networks and genetic algorithms in this paper. In first, a parametric axial fan blade model is established with constraints imposed on several parameters. The chord length, maximum camber, maximum camber position, blade thickness, and airfoil stagger angle are considered as an optimization parameter of axial fan. The static pressure efficiency and static pressure of axial fan are regarded as the optimization objectives. An optimization calculation of an axial fan blade is carried out based on the combination of artificial neural network and genetic algorithm. The objective aim of optimization is to improve the static pressure efficiency, the static pressure of axial fan and to reduce the flow loss of axial fan. Numerical results of axial fan demonstrate that the pressure distribution gradient and turbulent kinetic energy contour maps of the optimized axial fan are effectively suppressed within the impeller region compared with that of original axial fan. Furthermore, the internal flow stability of the optimized axial fan also is significantly improved by studying the pressure fluctuation and the Fast Fourier Transform (FFT) of pressure fluctuation. Experimental results of axial fan aerodynamic performance further demonstrate that the static pressure of the optimized axial fan rises as much as 90.93 Pa and the improved static pressure efficiency is effectively improved as much as 7.43% at the design flow rates compared with that of the original axial fan. The application of optimized axial flow fans is of great significance in energy-saving of energy equipment.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141779382","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 : 2024-07-23DOI: 10.1177/09576509241266284
Faiz T Jodah, Wissam H Alawee, Hayder A Dhahad, ZM Omara
Solving global water shortages has become an urgent challenge, hindering sustainable development. Therefore, comparing different solar still designs from application and economic perspectives is necessary. Solar distillation is considered a major innovation in the alternative energy sector for purifying brackish or brine water into clean water. Despite the extensive literature on improved solar stills, determining the most efficient designs for residential and industrial applications remains difficult. This review compares the productivity of spherical, hemispherical, and tubular solar still designs. The aim is to study the factors that influence the efficiency of each type and to analyze recent research and results obtained under different conditions. The results show that innovations in solar distillation design can take many forms to improve efficiency and productivity. For example, adding parabolic mirrors can increase productivity in spherical, hemispherical, and tubular stills by 35 to 70%. Likewise, innovative designs such as rotating spheres and changing bowl shapes significantly increased the productivity of spherical and hemispherical stills. Likewise, retrofitting a still with vacuum generation technology can significantly increase yields by 50 to 70%. In addition, using nanomaterials, especially nanophase change materials (NPCM), has increased the efficiency of the spherical and tubular stills by 116.5%, producing 7.62 kg/m2 per day. Therefore, the NPCM-equipped model was still the most efficient option among the three designs.
{"title":"Evaluating the performance of spherical, hemispherical, and tubular solar stills with various configurations - A detailed review","authors":"Faiz T Jodah, Wissam H Alawee, Hayder A Dhahad, ZM Omara","doi":"10.1177/09576509241266284","DOIUrl":"https://doi.org/10.1177/09576509241266284","url":null,"abstract":"Solving global water shortages has become an urgent challenge, hindering sustainable development. Therefore, comparing different solar still designs from application and economic perspectives is necessary. Solar distillation is considered a major innovation in the alternative energy sector for purifying brackish or brine water into clean water. Despite the extensive literature on improved solar stills, determining the most efficient designs for residential and industrial applications remains difficult. This review compares the productivity of spherical, hemispherical, and tubular solar still designs. The aim is to study the factors that influence the efficiency of each type and to analyze recent research and results obtained under different conditions. The results show that innovations in solar distillation design can take many forms to improve efficiency and productivity. For example, adding parabolic mirrors can increase productivity in spherical, hemispherical, and tubular stills by 35 to 70%. Likewise, innovative designs such as rotating spheres and changing bowl shapes significantly increased the productivity of spherical and hemispherical stills. Likewise, retrofitting a still with vacuum generation technology can significantly increase yields by 50 to 70%. In addition, using nanomaterials, especially nanophase change materials (NPCM), has increased the efficiency of the spherical and tubular stills by 116.5%, producing 7.62 kg/m<jats:sup>2</jats:sup> per day. Therefore, the NPCM-equipped model was still the most efficient option among the three designs.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141779383","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 : 2024-07-23DOI: 10.1177/09576509241264441
M. Sonachalam, V. Manieniyan, R. Senthilkumar
Researchers demonstrated that implementing new combustion technology and optimising fuel quantity results in a significant reduction in traditional fossil fuel usage and emission levels. The Reactivity Controlled Compression Ignition (RCCI) combustion strategy is one of the low temperature combustion technologies, and it is used to reduce the overall combustion temperature while also providing better combustion control. This study looks into RCCI combustion technology, which uses conventional diesel fuel as the high reactivity fuel (HRF) injected through the injector and acetylene gas as the low reactivity fuel (LRF) injected into the cylinder via a modified inlet manifold alongside air. The modified engine setup was tested for performance, emissions, and combustion under various load conditions, as well as different mass flow rates of acetylene gas, a low reactivity fuel that is injected with air. The flow field of the low reactivity fuel at the inlet manifold is analysed using the Computational Fluid Dynamics principle, which is used to determine the best flow rate for improving combustion quality. According to the simulation results, the optimal acetylene flow rate is 3 Litres Per Minute (LPM), and experimentation shows that at 3 LPM acetylene injection, the brake thermal efficiency (BTE) improves by about 3.2%, and emissions such as carbon monoxide (CO), hydrocarbon (HC), smoke intensity, and oxides of nitrogen (NOx) are reduced by about 35%, 17%, 10%, and 21%, respectively.
{"title":"Optimization on manifold injection in DI diesel engine fuelled with acetylene","authors":"M. Sonachalam, V. Manieniyan, R. Senthilkumar","doi":"10.1177/09576509241264441","DOIUrl":"https://doi.org/10.1177/09576509241264441","url":null,"abstract":"Researchers demonstrated that implementing new combustion technology and optimising fuel quantity results in a significant reduction in traditional fossil fuel usage and emission levels. The Reactivity Controlled Compression Ignition (RCCI) combustion strategy is one of the low temperature combustion technologies, and it is used to reduce the overall combustion temperature while also providing better combustion control. This study looks into RCCI combustion technology, which uses conventional diesel fuel as the high reactivity fuel (HRF) injected through the injector and acetylene gas as the low reactivity fuel (LRF) injected into the cylinder via a modified inlet manifold alongside air. The modified engine setup was tested for performance, emissions, and combustion under various load conditions, as well as different mass flow rates of acetylene gas, a low reactivity fuel that is injected with air. The flow field of the low reactivity fuel at the inlet manifold is analysed using the Computational Fluid Dynamics principle, which is used to determine the best flow rate for improving combustion quality. According to the simulation results, the optimal acetylene flow rate is 3 Litres Per Minute (LPM), and experimentation shows that at 3 LPM acetylene injection, the brake thermal efficiency (BTE) improves by about 3.2%, and emissions such as carbon monoxide (CO), hydrocarbon (HC), smoke intensity, and oxides of nitrogen (NOx) are reduced by about 35%, 17%, 10%, and 21%, respectively.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141779384","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 : 2024-06-21DOI: 10.1177/09576509241260795
Yutian Chen, Qun Zheng, Yuting Jiang, Bin Jiang
The application of inverse design in engineering is constrained by uncertainty over when to cease calculations owing to solution fluctuations and suboptimal aerodynamic parameter distribution. The proposed method for inverse design optimization incorporates active subspace assistance to effectively address these significant limitations. The optimal load distribution is achieved by the integration of sparse polynomial approximation and genetic algorithm. Furthermore, active subspace method is employed to solve the control zone of optimal static pressure/load distribution. The inverse design calculation is terminated when current load distribution falls completely within the control zone. Within the control zone, all static pressure/load distributions following a certain variance are guaranteed to provide nearly identical aerodynamic performance. The results indicate that the static pressure/load distribution of the final solution entirely falls within the control zone, while its aerodynamic performance approximates the optimal target value. In comparison to the initial solution, the final solution exhibits a significant decrease of 3.6% in the total pressure loss coefficient.
{"title":"Inverse design optimization of the compressor cascade airfoil assisted by active subspace approach","authors":"Yutian Chen, Qun Zheng, Yuting Jiang, Bin Jiang","doi":"10.1177/09576509241260795","DOIUrl":"https://doi.org/10.1177/09576509241260795","url":null,"abstract":"The application of inverse design in engineering is constrained by uncertainty over when to cease calculations owing to solution fluctuations and suboptimal aerodynamic parameter distribution. The proposed method for inverse design optimization incorporates active subspace assistance to effectively address these significant limitations. The optimal load distribution is achieved by the integration of sparse polynomial approximation and genetic algorithm. Furthermore, active subspace method is employed to solve the control zone of optimal static pressure/load distribution. The inverse design calculation is terminated when current load distribution falls completely within the control zone. Within the control zone, all static pressure/load distributions following a certain variance are guaranteed to provide nearly identical aerodynamic performance. The results indicate that the static pressure/load distribution of the final solution entirely falls within the control zone, while its aerodynamic performance approximates the optimal target value. In comparison to the initial solution, the final solution exhibits a significant decrease of 3.6% in the total pressure loss coefficient.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141546990","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 : 2024-06-14DOI: 10.1177/09576509241262188
Yongbo Du, Yuanhang Zhang, Jingkun Zhang, Defu Che
The self-excited thermoacoustic instability (SETAI) frequently occurs in combustion equipment, leading to intense mechanical vibration, big noise and flame instability. SETAI poses a substantial challenge to the advancement of combustion technology, chiefly due to its complex mechanism. Our previous research has demonstrated that altering the premixed chamber length upstream of furnace can impact the interaction between heat release and sound pressure oscillations, which potentially enables SETAI control. However, supply duct is generally not straight, and changing the premixed section is impractical and unsafe. This paper aims to investigate the influence of introducing elbows and adjusting the supply duct length preceding the premixing stage on SETAI behavior. The goal is to offer guidance for the safe and convenient control of SETAI. Finds reveal that incorporating an elbow in the premixed chamber or changing its position does not affect sound wave propagation along the duct’s center axis within a low frequency regime when maintaining a constant total equivalent length. In systems with both separate and premixed sections, the oscillation pattern is determined by the total time required for acoustic propagation throughout the entire supply system. Consequently, modifications to either of these lengths can impact SETAI.
{"title":"The self-excited thermoacoustic instability behavior of a premixed hedge combustor with an elbow-connection or T-shape supply system","authors":"Yongbo Du, Yuanhang Zhang, Jingkun Zhang, Defu Che","doi":"10.1177/09576509241262188","DOIUrl":"https://doi.org/10.1177/09576509241262188","url":null,"abstract":"The self-excited thermoacoustic instability (SETAI) frequently occurs in combustion equipment, leading to intense mechanical vibration, big noise and flame instability. SETAI poses a substantial challenge to the advancement of combustion technology, chiefly due to its complex mechanism. Our previous research has demonstrated that altering the premixed chamber length upstream of furnace can impact the interaction between heat release and sound pressure oscillations, which potentially enables SETAI control. However, supply duct is generally not straight, and changing the premixed section is impractical and unsafe. This paper aims to investigate the influence of introducing elbows and adjusting the supply duct length preceding the premixing stage on SETAI behavior. The goal is to offer guidance for the safe and convenient control of SETAI. Finds reveal that incorporating an elbow in the premixed chamber or changing its position does not affect sound wave propagation along the duct’s center axis within a low frequency regime when maintaining a constant total equivalent length. In systems with both separate and premixed sections, the oscillation pattern is determined by the total time required for acoustic propagation throughout the entire supply system. Consequently, modifications to either of these lengths can impact SETAI.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141342739","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 : 2024-06-14DOI: 10.1177/09576509241260085
Zhongqiang Wu, Xiaoyu Hu
This paper proposes an SOC estimation method for lithium battery, which combines the online parameter identification and an improved particle filter algorithm. Targeted at the particle degradation issue in particle filtering, grey wolf optimization is introduced to optimize particle distribution. Its strong global optimization ability ensures particle diversity, effectively suppresses particle degradation, and improves the filtering accuracy. The recursive least square method with forgetting factor is also introduced to update the model parameters in a real-time manner, which further improves the estimation accuracy of SOC alternately with the improved particle filter algorithm. Experimental results validate the proposed method, with an average estimation error less than ±0.15%. Compared with conventional extended Kalman filter and unscented Kalman filter algorithms, the proposed algorithm has higher estimation accuracy and stability for battery SOC estimation.
{"title":"SOC estimation of lithium battery based on online parameter identification and an improved particle filter algorithm","authors":"Zhongqiang Wu, Xiaoyu Hu","doi":"10.1177/09576509241260085","DOIUrl":"https://doi.org/10.1177/09576509241260085","url":null,"abstract":"This paper proposes an SOC estimation method for lithium battery, which combines the online parameter identification and an improved particle filter algorithm. Targeted at the particle degradation issue in particle filtering, grey wolf optimization is introduced to optimize particle distribution. Its strong global optimization ability ensures particle diversity, effectively suppresses particle degradation, and improves the filtering accuracy. The recursive least square method with forgetting factor is also introduced to update the model parameters in a real-time manner, which further improves the estimation accuracy of SOC alternately with the improved particle filter algorithm. Experimental results validate the proposed method, with an average estimation error less than ±0.15%. Compared with conventional extended Kalman filter and unscented Kalman filter algorithms, the proposed algorithm has higher estimation accuracy and stability for battery SOC estimation.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141343001","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 : 2024-06-01DOI: 10.1177/09576509231225275
Junying Wei, Gang Li, Wenwen Chang, Chenrui Zhang, Liang Yuan, Xueyi Li, Jidai Wang
For research on the effect of different working loads on the deformation of variable base circle radius scroll expander scroll teeth, a multi-field-coupled calculation method is proposed to reveal the deformation law of scroll teeth under different working loads. In this paper, the equations of the variable base radius profile are derived using the normal isometric method to establish a three-dimensional model of the variable base radius scroll expander. The CFD dynamic mesh technique is used to simulate the working process of a variable base radius scroll expander to obtain the flow field variation in the inner part of the working chamber. The results of the simulation are applied to the scroll teeth by interpolation to analyze the deformation of the scroll under single-field loading and multi-field coupling, to obtain the deformation law of the scroll teeth. The results of the study show that the deformation of the scroll teeth does not decrease linearly with the involute spreading angle from the head to the tail of the teeth due to the uneven temperature distribution of the scroll expander. The thermal stress of the temperature load impacts the deformation trend and amount of the scroll tooth, whereas the gas force load just modifies the amount of scroll tooth deformation and has a lower effect on the scroll tooth's deformation trend. Under different loads, the same deformation and different deformation on the scroll teeth can interact with each other to reduce the scroll tooth deformation to a certain extent.
{"title":"Numerical analysis on the deformation of scroll teeth of variable base circle radius scroll expander","authors":"Junying Wei, Gang Li, Wenwen Chang, Chenrui Zhang, Liang Yuan, Xueyi Li, Jidai Wang","doi":"10.1177/09576509231225275","DOIUrl":"https://doi.org/10.1177/09576509231225275","url":null,"abstract":"For research on the effect of different working loads on the deformation of variable base circle radius scroll expander scroll teeth, a multi-field-coupled calculation method is proposed to reveal the deformation law of scroll teeth under different working loads. In this paper, the equations of the variable base radius profile are derived using the normal isometric method to establish a three-dimensional model of the variable base radius scroll expander. The CFD dynamic mesh technique is used to simulate the working process of a variable base radius scroll expander to obtain the flow field variation in the inner part of the working chamber. The results of the simulation are applied to the scroll teeth by interpolation to analyze the deformation of the scroll under single-field loading and multi-field coupling, to obtain the deformation law of the scroll teeth. The results of the study show that the deformation of the scroll teeth does not decrease linearly with the involute spreading angle from the head to the tail of the teeth due to the uneven temperature distribution of the scroll expander. The thermal stress of the temperature load impacts the deformation trend and amount of the scroll tooth, whereas the gas force load just modifies the amount of scroll tooth deformation and has a lower effect on the scroll tooth's deformation trend. Under different loads, the same deformation and different deformation on the scroll teeth can interact with each other to reduce the scroll tooth deformation 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":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141403749","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 : 2024-06-01DOI: 10.1177/09576509241231020
Peter R Hooper
Atmospheric landfill gas emissions present serious problems when trying to counter the effects of global warming. The main constituent of landfill gas is methane, a more damaging greenhouse gas than CO2. European Union directives require the control and collection of landfill gases and promote energy recovery via combustion of the gas. A key challenge for combustion of landfill gas is the highly corrosive nature of the gas constituents which causes heightened maintenance and failure of applied engine systems. Conventional engines suffer from the effects of corrosion; however, stepped piston engine technology has yet to be considered for operational use at landfill sites. The engine has inherent advantages for such an application when compared with current conventional engines. The engine allows improved lubricating oil health compared to conventional engines and hence reduced oil use. This study discusses the challenges along with modelling of stepped piston and equivalent four-stroke engine solutions.
{"title":"Energy recovery from landfill gas emissions using a stepped piston segregated scavenge engine","authors":"Peter R Hooper","doi":"10.1177/09576509241231020","DOIUrl":"https://doi.org/10.1177/09576509241231020","url":null,"abstract":"Atmospheric landfill gas emissions present serious problems when trying to counter the effects of global warming. The main constituent of landfill gas is methane, a more damaging greenhouse gas than CO2. European Union directives require the control and collection of landfill gases and promote energy recovery via combustion of the gas. A key challenge for combustion of landfill gas is the highly corrosive nature of the gas constituents which causes heightened maintenance and failure of applied engine systems. Conventional engines suffer from the effects of corrosion; however, stepped piston engine technology has yet to be considered for operational use at landfill sites. The engine has inherent advantages for such an application when compared with current conventional engines. The engine allows improved lubricating oil health compared to conventional engines and hence reduced oil use. This study discusses the challenges along with modelling of stepped piston and equivalent four-stroke engine solutions.","PeriodicalId":20705,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141404772","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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