Tianyu Liu¹, Chang Wen^1,2,3,*, Wenyu Wang¹, Kai Yan³, Yongjun Xia⁴, Rui Li³, Juan Liu⁴, Yang Zhang¹

Energy Engineering, Vol.118, No.3, pp. 473-485, 2021, DOI:10.32604/EE.2021.014870

Abstract Pretreatment before biomass combustion is significant for its efficient utilization and that combined water washing and carbonization can be efficient. An agricultural processing residues sesame stalk was selected and carried out two pretreatments separately, i.e., water washing-torrefaction (W-T) and torrefaction-water washing (T-W), to explore the effect on the fuel properties, combustion characteristics and particulate matter (PM) emission. The obtained biochar was also combusted under air and oxy50 (CO₂:O₂ = 50:50) conditions for the sake of investigating the effect of pretreatment and combustion atmosphere. The results indicate that, W-T and T-W both not only have great effect… More >

Vin Cent Tai^1,*, Yong Chai Tan¹, Nor Faiza Abd Rahman¹, Chee Ming Chia², Mirzhakyp Zhakiya², Lip Huat Saw³

Energy Engineering, Vol.118, No.3, pp. 507-516, 2021, DOI:10.32604/EE.2021.014868

Abstract Accurate prediction of wind turbine power curve is essential for wind farm planning as it influences the expected power production. Existing methods require detailed wind turbine geometry for performance evaluation, which most of the time unattainable and impractical in early stage of wind farm planning. While significant amount of work has been done on fitting of wind turbine power curve using parametric and non-parametric models, little to no attention has been paid for power curve modelling that relates the wind turbine design information. This paper presents a novel method that employs artificial neural network to More >

Vin Cent Tai^1,*, Yong Chai Tan¹, Nor Faiza Abd Rahman¹, Hui Xin Che², Chee Ming Chia², Lip Huat Saw³, Mohd Fozi Ali⁴

Energy Engineering, Vol.118, No.3, pp. 715-725, 2021, DOI:10.32604/EE.2021.014865

Abstract Electricity demand is also known as load in electric power system. This article presents a Long-Term Load Forecasting (LTLF) approach for Malaysia. An Artificial Neural Network (ANN) of 5-layer Multi-Layered Perceptron (MLP) structure has been designed and tested for this purpose. Uncertainties of input variables and ANN model were introduced to obtain the prediction for years 2022 to 2030. Pearson correlation was used to examine the input variables for model construction. The analysis indicates that Primary Energy Supply (PES), population, Gross Domestic Product (GDP) and temperature are strongly correlated. The forecast results by the proposed… More >

Jianguo Zhang¹, Biao Hu^2,*, Xiyuan Li¹, Hongxing Zhou², Zhixu Dai³, Yanlei Lu³, Deyang Wang²

Energy Engineering, Vol.118, No.3, pp. 605-614, 2021, DOI:10.32604/EE.2021.014655

Abstract To accurately predict the risk of coal and gas outburst and evaluate the reliability of desorption indexes of drilling cuttings (K₁ and ∆h₂) in No. 16 coal seam of Pingmei No. 12 coal mine, two sets of coal samples were selected from the target coal seams for proximate analyses, methane adsorption/desorption tests, and desorption indexes of drilling cuttings tests. The results indicated that the desorption volume in the initial stage of desorption is large, and increases slowly in the later stage. The methane desorption volume of PMD1 and PMD2 coal samples accounts for 15.14%–18.09% and 15.72%–18.17%… More >

Lu Li¹, Yuzhen Fan², Xinglang Su^1,*, Gefei Qiu¹

Energy Engineering, Vol.118, No.3, pp. 565-580, 2021, DOI:10.32604/EE.2021.014627

Abstract Because of the randomness and uncertainty, integration of large-scale wind farms in a power system will exert significant influences on the distribution of power flow. This paper uses polynomial normal transformation method to deal with non-normal random variable correlation, and solves probabilistic load flow based on Kriging method. This method is a kind of smallest unbiased variance estimation method which estimates unknown information via employing a point within the confidence scope of weighted linear combination. Compared with traditional approaches which need a greater number of calculation times, long simulation time, and large memory space, Kriging More >

Jaime Francisco de Sousa Resende^1,*, Andrea Lucia Teixeira Charbel², Teresa Cristina Bessa Nogueira Assunção³

Energy Engineering, Vol.118, No.3, pp. 615-629, 2021, DOI:10.32604/EE.2021.014588

Abstract Buildings represent a significant share of the world’s energy consumption, and the sector has drawn the attention of governments, which have adopted policies to reduce energy expenditure. The Certifications of Energy Efficiency in Buildings stand out as one possible solution to achieve this goal, employed in several countries worldwide. The European Union presents advanced energy assessment programs for buildings, being a reference and model for several other regulations in the world. The Energy Certification System for Buildings (SCE) of Portugal is considered a success case, reflected in the significant number of energy certificates issued. The… More >

Yukun Lv, Yuechi Wang^*, Jiawen Wang, Jing Wang, Jiaxi Yang

Energy Engineering, Vol.118, No.3, pp. 631-642, 2021, DOI:10.32604/EE.2021.014578

Abstract In recent years, more than 50% of the cities in the inland area of our country have suffered from moderate pollution. It can affect the distribution of electric field along the surface of insulator and the pollution characteristics of its surface area, even endanger the safe operation of transmission lines. This paper takes the XSP-160 porcelain three umbrella insulator under the action of 0–±30 kV DC voltage as the research object, and establishes the physical model of the insulator; uses COMSOL software to simulate the electric field of the insulator. The comparison with the results… More >

Jingying Li¹, Tiejun Zhu¹, Fengming Li¹, Dong Wang¹, Xianbiao Bu², Lingbao Wang^2,*

Energy Engineering, Vol.118, No.3, pp. 517-534, 2021, DOI:10.32604/EE.2021.014464

Abstract The single well geothermal heating (SWGH) technology has attracted extensive attention. To enhance heat extraction from SWGH, a mathematical model describing heat transfer is set up, and the key influence factor and heat transfer enhancement method are discussed by thermal resistance analysis. The numerical results show that the thermal resistance of rock is far greater than that of well wall and fluid. So, reducing rock thermal resistance is the most effective method for enhancing the heat extraction power. For geothermal well planning to drill: rock thermal resistance can be reduced by increasing well diameter and… More >

Zhongjia Li¹, Jianfeng Pan^1,*, Hongjun Liu¹, Baowei Fan¹, Wenming Yang², Abiodun Oluwaleke Ojo¹

Energy Engineering, Vol.118, No.3, pp. 581-603, 2021, DOI:10.32604/EE.2021.014378

Abstract In order to improve the performance of the rotary engine, this paper has designed a new type of dual-pit rotary engine combustion chamber structure, and compares the combustion and emission characteristics with the rotary engine with a traditional combustion chamber. The existence of the dual-pit combustion chamber strengthens the overall vortex intensity in the cylinder, effectively promotes the mixing process of fuel and air in the cylinder, the maximum combustion pressure in the cylinder increased by 8.6%, significantly increases the diffusion combustion speed, and significantly improves the dynamic performance of the rotary engine. On this… More >

Taihong Liu¹, Dingchen Wu^2,*, Fei Xu³, Panpan Song², Mingshan Wei², Jian Wu¹, Xiaochun Bai¹

Energy Engineering, Vol.118, No.3, pp. 535-548, 2021, DOI:10.32604/EE.2021.014326

Abstract In view of the Three North areas existing wind power absorption and environment pollution problems, the previous scholars have improved the wind abandon problem by adding electrothermal coupling equipment or optimizing power grid operation. In this paper, an electrothermal integrated energy system including heat pump and thermal storage units was proposed. The scheduling model was based on the load data and the output characteristics of power units, each power unit capacity was programmed without constraints, and the proposed scheduling model was compared with the traditional combined heat and power scheduling model. Results showed that the More >