Saif S. Hasan¹, Ali Sh. Baqir¹, Hameed B. Mahood^2,*

Energy Engineering, Vol.118, No.6, pp. 1595-1609, 2021, DOI:10.32604/EE.2021.017433

Abstract In the present study, the effect of injecting air bubble size on the thermal performance of a vertical counter-current shell and coiled tube heat exchanger is experimentally investigated. The experiments were accomplished in a cylindrical shape heat exchanger with a 50 cm height and 15 cm outer diameter. Copper coil with 3.939 m equivalent length and 0.6 cm outer diameter was used to carry the hot fluid (water). Four different cold fluid (shell side) flow rates under laminar flow conditions (316 ≤ Re ≤ 1223), constant hot (coil side) flow rate fluid rates , four different injected air flow rates , invariant… More >

Tayyebeh Yazarlou^*, Mohammad Djavad Saghafi

Energy Engineering, Vol.118, No.6, pp. 1783-1797, 2021, DOI:10.32604/EE.2021.017282

Abstract The room's plan shape, the area of the window, and the impact of the materials are significant parameters in determining the thermal needs of buildings. In traditional houses of the hot and dry climate of Iran, the plan shape of the room, the ratio of the window area to the floor area, and the comparison between traditional and prevalent materials have been less studied. This study investigated the thermal performance of seven different models of the plan shape, five different ratios of window area to plan area, and three material structures in a selected room of Yazd City using EnergyPlus… More >

Bachir Melzi¹, Nesrine Kefif², Mamdouh El Haj Assad^3,*, Haleh Delnava⁴, Abdulkadir Hamid⁵

Energy Engineering, Vol.118, No.6, pp. 1767-1781, 2021, DOI:10.32604/EE.2021.017270

Abstract This work presents a hybrid power system consisting of photovoltaic and solid oxide fuel cell (PV-SOFC) for electricity production and hydrogen production. The simulation of this hybrid system is adjusted for Bou-Zedjar city in north Algeria. Homer software was used for this simulation to calculate the power output and the total net present cost. The method used depends on the annual average monthly values of clearness index and radiation for which the energy contributions are determined for each component of PV/SOFC hybrid system. The economic study is more important criterion in the proposed hybrid system, and the results show that… More >

Ramkiran Bhallamudi^1,2, Sudhakar Kumarasamy^3,4,5, Chinnayan Karuppaiyah Sundarabalan^1,*

Energy Engineering, Vol.118, No.6, pp. 1827-1838, 2021, DOI:10.32604/EE.2021.016798

Abstract This study presents an experimental performance of a solar photovoltaic module under clean, dust, and shadow conditions. It is found that there is a significant decrease in electrical power produced (40% in the case of dust panels and 80% in the case of shadow panels) and a decrease in efficiency of around 6% in the case with dust and 9% in the case with the shadow, as compared to the clean panel. From the results, it is clear that there is a substantial effect of a partial shadow than dust on the performance of the solar panel. This is due… More >

Xin Xu^*, Lian Zhang^*

Energy Engineering, Vol.118, No.6, pp. 1905-1920, 2021, DOI:10.32604/EE.2021.016738

Abstract This paper briefly summarizes the current status of typical solar thermal power plant system, including system composition, thermal energy storage medium and performance. The thermo-physical properties of the storage medium are some of the most important factors that affect overall efficiency of the system, because some renewable energy sources such as solar and wind are unpredictable. A thermal storage system is therefore necessary to store energy for continuous usage. Based on the form of storage or the mode of system connection, heat exchangers of a thermal storage system can produce different temperature ranges of heat transfer fluid to realize energy… More >

Zhen Liu^1,3, Jianwen Wang^1,2,*, Fuzhong Bai³, Caifeng Wen^1,2, Yunchao Du¹

Energy Engineering, Vol.118, No.6, pp. 1627-1640, 2021, DOI:10.32604/EE.2021.016357

Abstract The yaw of the horizontal axis wind turbine results in the deflection of the wake flow field of the tower. The reasonable layout of wind farm can reduce the power loss of the downstream wind turbine generators due to the blocking effect of the upstream wake flow and increase the output power of the whole wind farm. However, there is still much space for further research. In this paper, experimental research is conducted on the near-wake deflection characteristics of wind turbine tower under yaw state, expecting the effect of throwing away a brick in order to get a gem. In… More >

Ahmed Abubakar Elwan^*, Mohammed Hafiz Habibuddin

Energy Engineering, Vol.118, No.6, pp. 1681-1701, 2021, DOI:10.32604/EE.2021.016291

Abstract With population growth around the world, municipal waste disposal and continued energy demand becomes some of the major challenges to deal with. In order to address these, an approach is required for an optimal waste management system that offers the population benefit with a lower environmental impact. This study evaluates the technical-economic and environmental impact analysis of a grid-connected waste to energy (WtE) plant to power a Univerisiti Teknologi Malaysia (UTM) community. The energy recovery potential of the waste stream was assessed using the life cycle assessment (LCA) method with GaBi^TM software (version 4). A technical, economic and environmental analysis… More >

Lei Wang¹, Zekun Wang^2,3,4,*, Yingjian Yang², Shuni Zhou⁵, Yehong Dong⁵, Fanghong Zhang⁵

Energy Engineering, Vol.118, No.6, pp. 1611-1626, 2021, DOI:10.32604/EE.2021.016010

Abstract China has abundant wind energy resources and huge development potential among developing countries. Japan is a developed country that planned to increase the use of renewable energy, especially wind energy. This research is aimed at reviewing the development of wind power and relevant policies between China and Japan. Firstly, we introduced the current status of global wind power development, such as the global installed capacity of wind power. The annual development of wind power generation in China and Japan is compared, and the distribution characteristics of wind resources are compared. Furthermore, the market share in China and Japan is introduced.… More >

Jianfeng Yang^*, Yu Ding

Energy Engineering, Vol.118, No.6, pp. 1839-1853, 2021, DOI:10.32604/EE.2021.015930

Abstract With the widespread application of power electronic equipment in the power grid, the harmonic problem of the power grid becomes more pronounced, reducing the efficiency of power production, transmission, and utilization, and interfering with the normal operation of the power grid. Based on the requirements of harmonic suppression and power system protection, a shunt active power filter (SAPF) is proposed as an effective harmonic suppression method. However, there are problems with impulse current and impulse voltage in the starting process of SAPF. Impulse current and impulse voltage cause the power grid and switchgear to bear greater current stress and voltage… More >

Xiyuan Li¹, Peng Chu^2,3,*, Zhuang Lu^2,3, Yuanyuan Liu^2,3, Zibin Zhu^2,3, Jin Gao^2,3, Xiaoxue Liao^2,3, Tao Yang^2,3

Energy Engineering, Vol.118, No.6, pp. 1811-1825, 2021, DOI:10.32604/EE.2021.015751

Abstract The permeability is a key factor to determine the efficiency of coalbed methane (CBM) production. The borehole enlargement technology using hydraulic and mechanical measures to cut coal is an effective method to increase the coal seam permeability and improve the efficiency of gas drainage. Reasonable design of the layout of boreholes is the prerequisite for efficient and economical gas drainage. In this paper, based on the strain-softening model, the stress and permeability model of the coal seam around the enlarged borehole was built, and based on the dual-medium model, the gas migration model in the coal seam was established. Then… More >