Estimate of the Wind Resource of Two Cities in the Sahara and Sahel in Chad
Abakar Mahamat Tahir,
Mahamat Adoum Abdraman,
Ruben Mouangue,
Alexis Kuitche
Issue:
Volume 9, Issue 6, November 2020
Pages:
86-94
Received:
30 October 2020
Accepted:
13 November 2020
Published:
16 December 2020
Abstract: The objective of this work is to map the wind resource of two cities of Ndjamena and Faya located respectively in Chadian Sahara and Sahel. As well as the evaluation of the annual energy produced at an altitude of 80m or 100m by the simulation of wind data from wind speed data collected from metrological stations in the Sahara and Sahel areas respectively in the cities of Ndjamena and Faya Airport, and available for five years. In this perspective, we start with the description of the site, the determination of the various wind parameters, such as the mathematical modeling of the wind frequency distribution: Weibull distribution and the numerical simulation of the real wind data collected over five years to provide predictions on sites in two cities of Ndjamena and Faya. Then, we estimate its wind potential, its prediction of the electrical energy produced and we carry out an analysis of the wind turbulence by taking into account the obstacles surrounding near the measurement mast of Ndjamena and Faya, the topography, the roughness of the site, the density and a judicious choice of wind turbines.
Abstract: The objective of this work is to map the wind resource of two cities of Ndjamena and Faya located respectively in Chadian Sahara and Sahel. As well as the evaluation of the annual energy produced at an altitude of 80m or 100m by the simulation of wind data from wind speed data collected from metrological stations in the Sahara and Sahel areas respe...
Show More
Experimental Study on Energy and Exergy Analysis of a Counter Hollow Fiber Membrane-based Humidifier
Zhipeng He,
Caihang Liang
Issue:
Volume 9, Issue 6, November 2020
Pages:
95-107
Received:
19 November 2020
Accepted:
1 December 2020
Published:
16 December 2020
Abstract: The counter hollow fiber membrane-based humidifier is used for air humidification, which avoids the problem of liquid droplets carryover in traditional liquid humidification technology. In this study, an experimental rig was established for the hollow fiber membrane humidification system. The effects of air mass flow rate, air temperature, air relative humidity, water mass flow rate, water temperature on air humidity ratio increase, air temperature difference, power consumption per unit of humidification, humidification efficiency, energy efficiency, exergy destruction and exergy efficiency were experimentally investigated using the energy and exergy method. The results reveal the enhancement of the exergy efficiency with the increase in inlet air relative humidity, inlet air dry bulb temperature, air mass flow rate, and water mass flow rate. The results show that the humidification performance of the system is strongly influenced by the water temperature, while the humidification effect is more significant for the low temperature and low air humidity. It was found that as the relative humidity and dry bulb temperature of the air increased, the exergy destruction decreased significantly and the exergy efficiency increased. Increasing the air mass flow rate and water flow temperature resulted in an increase in both exergy destruction and exergy efficiency, while increasing the water flow rate had little effect on exergy destruction and fire efficiency. The exergy efficiency of the system ranged from 0.37 to 0.71. The maximum exergy destruction was 3.74 W, which occurred at air RHa,1=30%, air temperature Ta,1=30°C, water temperature Tw,1=28°C, and air and water flow rates of 32 kg/h and 7 kg/h, respectively. The humidification efficiency of the system ranged from 0.712 to 0.925, and the power consumption per unit of humidification ranged from 0.94 g/(h•W) to 12.50 g/(h•W).
Abstract: The counter hollow fiber membrane-based humidifier is used for air humidification, which avoids the problem of liquid droplets carryover in traditional liquid humidification technology. In this study, an experimental rig was established for the hollow fiber membrane humidification system. The effects of air mass flow rate, air temperature, air rela...
Show More
Research and Application on Bed Material Preparation System of CFB Boiler
Huang Shuzhen,
Li Xinsheng
Issue:
Volume 9, Issue 6, November 2020
Pages:
108-114
Received:
7 December 2020
Accepted:
22 December 2020
Published:
31 December 2020
Abstract: This paper introduces a technology of preparing bed material with bottom slag of circulating fluidized bed boiler, and designs the system of filling the bed material into the furnace, which has been applied in engineering. This technology uses bottom slag to prepare bed material. Through screening treatment of developed ultra-fine roller screen, the bed material with particle size meeting combustion requirements is prepared and fed into fluidized bed furnace. It not only ensures the combustion effect of the boiler, but also saves a lot of bed material procurement and operation costs, at the same time, it reduces the discharge of boiler bottom slag, which is conducive to reducing pollutant emission. Moreover, some limestone which is not involved in the desulfurization reaction in the furnace is screened out and returned to the furnace again as bed material, so as to improve the utilization rate of limestone powder. The success of this system in engineering application provides a low-cost and reliable new bed material preparation and filling method for the industry, and provides a reliable guarantee for the combustion of CFB boilers. The system meets the requirements of energy conservation and environmental protection, enriches the auxiliary system of CFB boiler, improves the supporting level of auxiliary system of CFB boiler, and further promotes the application of clean combustion fluidized bed unit.
Abstract: This paper introduces a technology of preparing bed material with bottom slag of circulating fluidized bed boiler, and designs the system of filling the bed material into the furnace, which has been applied in engineering. This technology uses bottom slag to prepare bed material. Through screening treatment of developed ultra-fine roller screen, th...
Show More
