Home / Journals / ENERGY / Vol.117, No.1, 2020
  • Open Access

    ARTICLE

    Unsteady Natural Convection within an Attic-Shaped Space Subject to Sinusoidal Heat Flux on Inclined Walls

    Suvash C. Saha1,*, Ali M. Sefidan2, Atta Sojoudi3
    Energy Engineering, Vol.117, No.1, pp. 1-17, 2020, DOI:10.32604/EE.2020.010418
    Abstract Free convection inside an attic enclosure in which sinusoidal heat flux applied on the inclined walls and a constant temperature applied on the base wall has been investigated numerically to demonstrate the primary flow characteristics and heat transfer within the attic enclosure over daily routine cycles. To solve the governing equations, the finite volume technique has been utilized. After performing the grid independency and time step size tests, the roles of Rayleigh number (Ra) and the attic aspect ratio (AR) on the unsteady flow structure and heat transfer phenomenon are explained for a constant Prandtl number (0.72) for the air.… More >

  • Open Access

    ARTICLE

    A Novel Trenchless Detection Technology Based on Transient Electromagnetic Method for Power Poles

    Lingda Xu1, Dandi Zhang2, Jun Zhou3,*, Zhou He2, Xiao Fang2, Yonglin Zhi1
    Energy Engineering, Vol.117, No.1, pp. 19-26, 2020, DOI:10.32604/EE.2020.010409
    Abstract For the application of inspecting the construction status of distribution network poles, this paper proposed a novel detection technology for base plates, pulling plates, chucks (abbreviated as BPC) which are buried together with the power poles based on exerting external current excitation. The detection system consists of lead wires for BPC, an excitation generating circuit, a signal receiving coil, a signal conditioning circuit and an embedded processor. Compared with the traditional transient electromagnetic method, this technology is more suitable for detecting BPC which are buried shallowly, with higher sensitivity for depth changes and higher signal-to-noise ratio. Moreover, it can judge… More >

  • Open Access

    ARTICLE

    Research on the Measurement and Countermeasure of Coal Overcapacity in China: Based on Panel Data of 25 Provinces in China

    Rijia Ding1, Xingyao Zhou1,*, Rui Zhang1, Wanqiu Lu2
    Energy Engineering, Vol.117, No.1, pp. 27-39, 2020, DOI:10.32604/EE.2020.010372
    Abstract Coal is the main energy source in China. At present, the coal overcapacity is still serious in China. Accurately measuring the degree of China’s coal overcapacity can scientifically resolve the overcapacity, and is the premise of guiding the healthy development of coal industry and energy system. Using the translog cost function and the panel data of coal industry in all provinces of China from 2002 to 2011 and from 2012 to 2016, the research measures and compares the coal production capacity of “golden decade” and “cold winter” in China. The results show that: (1) The change of coal production capacity… More >

  • Open Access

    ARTICLE

    Performance and Cost Analysis of Energy Production from Offshore Wind Turbines

    Haytham Ayoub, Ehab Hussein Bani-Hani*
    Energy Engineering, Vol.117, No.1, pp. 41-47, 2020, DOI:10.32604/EE.2020.010412
    Abstract Offshore wind turbine is analyzed theoretically and experimentally for improving wind energy harvesting. The energy produced is calculated at different wind speeds. The wind speed curve is generated by measuring the wind speed on daily base for one year. Curves that show the power extraction for experimental study and from the theoretical calculations are generated. The energy production investigation is expanded over a period of 15 years after comparing the annual energy production in theory and practice. The study shows the cost of electricity over the same time period assuming different interest rates. Three time intervals are shown that are… More >

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