Fatiha Daoudi^1,*, Abdelkrim Naas¹, Omar Meglali^1,2, Radia Boudaira³, Ahmed Gueddim¹, A. M. Saeed⁴

Energy Engineering, Vol.120, No.8, pp. 1803-1815, 2023, DOI:10.32604/ee.2023.028423

Abstract The numerical simulations were performed using the AMPS-1D simulator to study the effects of the CZTS as an absorber layer and the contacts’ barrier height on the performance of four ZnO/CdS/CZTS solar cells. To obtain the best cell performances, the barrier heights of the back and front contacts were adjusted between 0.01, 0.77, 0.5, and 1.55 eV, respectively. For simulations, we used the lifetime mode, and the device performances were evaluated under AM1.5 illumination spectra. We found that the efficiency, fill factor, and open-circuit voltage were almost constant at a front contact barrier height of less than 0.31 eV. The… More > Graphic Abstract

Bing Wang^1,2,*, Lu Li¹, Xinru Jiang¹

Energy Engineering, Vol.120, No.8, pp. 1763-1773, 2023, DOI:10.32604/ee.2023.027846

Abstract Climate change and energy security issues are prominent challenges in current energy system management, which should be governed synergistically due to the feedback relationships between them. The “Energy Systems Management and Climate Change” Special Collection Issue in the journal of Energy Engineering provide insights into the field of energy systems management and climate change. From an extended perspective, this study discusses the key issues, research methods and models for energy system management and climate change research. Comprehensive and accurate prediction of energy supply and demand, the evaluation on the energy system resilience to climate change and the coupling methodology application… More > Graphic Abstract

Nisha Vasudevan^1,*, Vasudevan Venkatraman², A. Ramkumar¹, T. Muthukumar³, A. Sheela⁴, M. Vetrivel⁵, R. J. Vijaya Saraswathi⁶, F. T. Josh⁷

Energy Engineering, Vol.120, No.8, pp. 1747-1761, 2023, DOI:10.32604/ee.2023.027821

Abstract MigroGrid (MG) has emerged to resolve the growing demand for energy. But because of its inconsistent output, it can result in various power quality (PQ) issues. PQ is a problem that is becoming more and more important for the reliability of power systems that use renewable energy sources. Similarly, the employment of nonlinear loads will introduce harmonics into the system and, as a result, cause distortions in the current and voltage waveforms as well as low power quality issues in the supply system. Thus, this research focuses on power quality enhancement in the MG using hybrid shunt filters. However, the… More >

Huashan Li¹, Xiaoshuang Zhao^1,2, Sihao Huang^1,2, Lingbao Wang¹, Jiongcong Chen^1,*

Energy Engineering, Vol.120, No.8, pp. 1817-1835, 2023, DOI:10.32604/ee.2023.027668

Abstract Process heating constitutes a significant share of final energy consumption in the industrial sector around the world. In this paper, a high-temperature heat pump (HTHP) using flash tank vapor injection technology (FTVI) is proposed to develop low-temperature geothermal source for industrial process heating with temperature above 100°C. With heat sink output temperatures between 120°C and 150°C, the thermo-economic performance of the FTVI HTHP system using R1234ze(Z) as refrigerant is analyzed and also compared to the single-stage vapor compression (SSVC) system by employing the developed mathematical model. The coefficient of performance (COP), exergy efficiency (η_exe), net present value (NPV) and payback… More >

Xincan Song^1,3,4, Lin Wang^1,3,4,*, Cheng Yu^1,2, Jiaxin Chen^1,3,4, Linjie Ma^1,3,4

Energy Engineering, Vol.120, No.8, pp. 1837-1852, 2023, DOI:10.32604/ee.2023.027637

Abstract The coupled formation of wax crystals and hydrates is a critical issue for the safety of deep-sea oil and gas exploration and subsea transport pipeline flow. Therefore, this paper conducts an experimental study on the characteristics of methane hydrate formation in a water-in-oil (W/O) system with different wax crystal contents and explores the influence of different initial experimental pressures on the induction period and maximum rate of hydrate formation. The wavelet function was introduced to process the reaction rate and calculate the maximum speed of hydrate formation. Notably, the higher the pressure, the smaller the maximum rate of hydrate formation.… More >

Liqing Yan¹, Jiang Liu^1,2,*, Guangwei Ying³, Ning Zhang⁴

Energy Engineering, Vol.120, No.8, pp. 1919-1938, 2023, DOI:10.32604/ee.2023.027546

Abstract Recovery of waste heat from boiler flue gas is an effective way to improve energy utilization efficiency. Taking a heating station heating project as an example, the existing heating system of this heating station was analyzed for its underutilized flue gas waste heat and low energy utilization rate. Rankine cycle is an effective waste heat recovery method, and a steam boiler organic Rankine cycle (ORC) cogeneration waste heat utilization method is proposed. The system model simulation is constructed and verified. First, a thermodynamic model was constructed in MATLAB and five suitable work gases were selected to analyze the effects of… More > Graphic Abstract

Ming Li^1,*, Cairen Furifu¹, Chengyang Ge², Yunping Zheng¹, Shunfu Lin², Ronghui Liu²

Energy Engineering, Vol.120, No.8, pp. 1775-1801, 2023, DOI:10.32604/ee.2023.027215

Abstract As an effective carrier of integrated clean energy, the microgrid has attracted wide attention. The randomness of renewable energies such as wind and solar power output brings a significant cost and impact on the economics and reliability of microgrids. This paper proposes an optimization scheme based on the distributionally robust optimization (DRO) model for a microgrid considering solar-wind correlation. Firstly, scenarios of wind and solar power output scenarios are generated based on non-parametric kernel density estimation and the Frank-Copula function; then the generated scenario results are reduced by K-means clustering; finally, the probability confidence interval of scenario distribution is constrained… More >

Mingming Shi^1,*, Jun Zhang², Xuefeng Ge¹, Juntao Fei¹, Jiajun Tan³

Energy Engineering, Vol.120, No.8, pp. 1885-1897, 2023, DOI:10.32604/ee.2023.025788

Abstract With the wide application of renewable energy power generation technology, the distribution network presents the characteristics of multi-source and complex structure. There are potential risks in the stability of power system, and the problem of power quality is becoming more and more serious. This paper studies and proposes a power optimization cooperative control strategy for flexible fast interconnection device with energy storage, which combines the flexible interconnection technology with the energy storage device. The primary technology is to regulate the active and reactive power of the converter. By comparing the actual power value of the converter with the reference value,… More >

Wenhua Xu^1,3, Yuming Zhu², Yingrong Wei², Ya Su², Yan Xu^1,3, Hui Ji¹, Dehua Liu^1,3,*

Energy Engineering, Vol.120, No.7, pp. 1701-1715, 2023, DOI:10.32604/ee.2023.027703

Abstract Drilling costs of ultra-deep well is the significant part of development investment, and accurate prediction of drilling costs plays an important role in reasonable budgeting and overall control of development cost. In order to improve the prediction accuracy of ultra-deep well drilling costs, the item and the dominant factors of drilling costs in Tarim oilfield are analyzed. Then, those factors of drilling costs are separated into categorical variables and numerous variables. Finally, a BP neural network model with drilling costs as the output is established, and hyper-parameters (initial weights and bias) of the BP neural network is optimized by genetic… More >

Baran Hekimoğlu^*

Energy Engineering, Vol.120, No.7, pp. 1515-1540, 2023, DOI:10.32604/ee.2023.029024

Abstract Two novel improved variants of reptile search algorithm (RSA), RSA with opposition-based learning (ORSA) and hybrid ORSA with pattern search (ORSAPS), are proposed to determine the proportional, integral, and derivative (PID) controller parameters of an automatic voltage regulator (AVR) system using a novel objective function with augmented flexibility. In the proposed algorithms, the opposition-based learning technique improves the global search abilities of the original RSA algorithm, while the hybridization with the pattern search (PS) algorithm improves the local search abilities. Both algorithms are compared with the original RSA algorithm and have shown to be highly effective algorithms for tuning the… More > Graphic Abstract