Xiaojuan Lu, Qingbo Zhang^*

Energy Engineering, Vol.118, No.6, pp. 1729-1740, 2021, DOI:10.32604/EE.2021.014938

Abstract In the process of grid-connected photovoltaic power generation, there are high requirements for the quality of the power that the inverter breaks into the grid. In this work, to improve the power quality of the grid-connected inverter into the grid, and the output of the system can meet the grid-connected requirements more quickly and accurately, we exhibit an approach toward establishing a mixed logical dynamical (MLD) model where logic variables were introduced to switch dynamics of the single-phase photovoltaic inverters. Besides, based on the model, our recent efforts in studying the finite control set model predictive control (FCS-MPC) and devising… More >

Ahmed J. Hamad^*, Fawziea M. Hussien, Johain J. Faraj

Energy Engineering, Vol.118, No.5, pp. 1483-1497, 2021, DOI:10.32604/EE.2021.016867

Abstract The fluctuation in drying temperature influences the food products’ quality and drying time significantly during the drying process using an indirect solar dryer. One of the effective methods to reduce these variations in the temperature is based on thermal storage materials to control the drying temperature. An experimental investigation is presented in this study to evaluate the performance of an indirect solar dryer with air double pass using multiple phase change materials (PCM) as thermal storage materials. Two PCMs with different melting points are used to store the available heat energy during peak sunshine periods and reduce the drying temperature… More >

Vibhushit Gupta¹, Shubham K. Verma², Sanjeev Anand², Navin Gupta³, Yatheshth Anand^1,*

Energy Engineering, Vol.118, No.5, pp. 1317-1331, 2021, DOI:10.32604/EE.2021.016732

Abstract The utilization of energy in building sectors comprises 30–40% of the entire global energy consumption. Most of the energy is being utilized for cooling & heating the buildings. These cooling and heating depend on the nature of climate for different places. In this, the detailed analysis of the building envelope across five areas (viz. Srinagar, Jaisalmer, New Delhi, Thiruvananthapuram and Bangalore) representing different climatic zones had been carried out. Simulations are performed for these locations using eQUEST and ANSYS software. Three of the result output from the eQUEST simulation are used to assess the different cases. These outputs are: total… More >

Nugroho Agung Pambudi^1,*, Santiko Wibowo¹, Ranto¹, Lip Huat Saw²

Energy Engineering, Vol.118, No.5, pp. 1565-1576, 2021, DOI:10.32604/EE.2021.016642

Abstract Organic Rankine Cycle (ORC) is one of the solutions to utilize a low temperature geothermal fluid for power generation. The ORC system can be placed at the exit of the separator to extract energy from brine. Furthermore, one of the main components of the system and very important is the pump. Therefore, in this research, the pump rotation is examined to investigate the effect on power output and energy efficiency for low temperature geothermal fluid. The rotation is determined by using an inverter with the following frequencies: 7.5, 10, 12.5, 15 and 17.5 Hz, respectively. R-134 working fluid is employed… More >

Himanshu¹, Kunwar Pal², Sanjeev Jain³, S. K. Tyagi^1,*

Energy Engineering, Vol.118, No.5, pp. 1237-1251, 2021, DOI:10.32604/EE.2021.016489

Abstract A disruptive approach to a fundamental process has been applied in a biomass combustion device with two variable speed fans to supply air for gasification and another for combustion processes, separately. Besides, the preheating of secondary air, required for combustion process was also ensured through annulus chamber before being fed into the combustion chamber. The turbulent flow and homogenous mixing were also ensured by controlling the flow rate resulting in the reduced emissions of carbon monoxide (CO) and fine particulate matter (PM 2.5, particulate matter having aerodynamic diameter <2.5 micron). The design approach applied here has also ensured the homogeneous… More >

Manar B. AL-Hajji^1,*, Nabeel Abu Shaban², Shahnaz Al Khalil², Ayat Al-Jarrah³

Energy Engineering, Vol.118, No.5, pp. 1425-1438, 2021, DOI:10.32604/EE.2021.016413

Abstract Solar energy is regarded as one of the promising renewable energy sources in the world.The main aim of this study is to use the Taguchi-Grey relational grade analysis to optimize the performance of two Solar Air Heaters (SAHs). A typical Grey–Taguchi method was applied. The Orthogonal Array, Signal-to-Noise ratio, Grey Relational Grade, and Analysis of Variance were employed to investigate the performance characteristics of SAH. Experimental observations were made in agreement with Jordanian climate 32°00′ N latitude and 36°00′ E longitude with a solar intensity of 500 W\m². The operating factors selected for optimization are the tilt angle (T) with… More >

Mahmoud Abdo Tantawy¹, Ahmed A. M. Elgibaly¹, Ahmed Mohamed Farag^2,*

Energy Engineering, Vol.118, No.5, pp. 1411-1423, 2021, DOI:10.32604/EE.2021.016192

Abstract In recent years, many trials have been made to use the Rate Transient Analysis (RTA) techniques as a method to describe the gas condensate reservoirs. The problem with using these techniques is the multi-phase behavior of the gas condensate reservoirs. Therefore, the Pressure Transient Analysis (PTA) is commonly used in this case to analyze the reservoir parameters. In this paper, we are going to compare the results of both PTA and RTA of three wells in gas condensate reservoirs. The comparison showed a great match between the results of the two mentioned techniques for the first time using a reference… More >

J. Kananathan^1,2, M. Samykano^2,*, K. Kadirgama³, D. Ramasamy², M. M. Rahman²

Energy Engineering, Vol.118, No.5, pp. 1305-1315, 2021, DOI:10.32604/EE.2021.016131

Abstract Fused deposition modeling (FDM)-3D printing has been the favored technology to build functional components in various industries. The present study investigates infill percentage and infill pattern effects on the printed parts’ impact properties through the 3D printing technique using coconut wood-filled PLA composites. Mathematical models are also proposed in the present study with the aim for future property prediction. According to the ASTM standard, fifteen specimens with different parameter combinations were printed using a low-cost FDM 3D printer to evaluate their impact properties. Statistical analysis was performed using MINITAB to validate the experimental data and model development. The experimental outcomes… More >

Zihao Wang, Dunxi Yu^*, Jingkun Han, Jianqun Wu

Energy Engineering, Vol.118, No.5, pp. 1267-1276, 2021, DOI:10.32604/EE.2021.016107

Abstract Typical biomass torrefaction is a mild pyrolysis process under conditions of ordinary pressure, low temperature (200–300°C) and inert atmosphere. Torrefaction is considered to be a competitive technology for biomass pretreatment, but its impacts on the emissions of particulate matter from biomass combustion are worthy of further study. In this paper, three kinds of biomass, i.e., bagasse, wheat straw and sawdust were selected for torrefaction pretreatment and the impacts of torrefaction on the emission characteristics of PM₁₀ from biomass combustion were investigated. The combustion experiments were carried out on a drop tube furnace. The combustion-generated particulate and bulk ash samples were… More >

I. Samylingam¹, Navid Aslfattahi², K. Kadirgama^1,*, Mahendran Samykano³, L. Samylingam⁴, R. Saidur^4,5

Energy Engineering, Vol.118, No.5, pp. 1253-1265, 2021, DOI:10.32604/EE.2021.016087

Abstract In this study, nanocomposite of ternary nitrate molten salt induced with MXene is developed. LiNO₃-NaNO₃-KNO₃ with wt% of 35:12:53 and 35:10:55 are produced and doped with MXene in the wt% of 0.2, 0.5, 1.0, and 1.5. FTIR result indicates the composites had no chemical reaction occurred during the preparation. UV-VIS analysis shows the absorption enhancement with respect to the concentration of MXene. Thermogravimetric analysis (TGA) was used to measure the thermal stability of the LiNO₃-NaNO₃-KNO₃ induced with MXene. The ternary molten salts were stable at temperature range of 600–700°C. Thermal stability increases with the addition of MXene. 1.5 wt% of… More >