جستجوی مقالات مرتبط با کلیدواژه "تشعشع" در نشریات گروه "برق"

In the present paper, a two-phase simulation of atmospheric aerosol (air, pollution, fine particles of dust, and vehicles pollutants) is carried out to investigate the pollutants dispersion and heat transfer (conduction-convection-radiation) in urban street canyons under haze-fog conditions. Numerical calculations were considered for four time periods during the day, including: 10 am, 1 pm, 4 pm, and 8 pm on the first days of April, July, October, and January. For this purpose, Computational Fluid Dynamics (CFD) method and the simulation are used and dynamic characteristics of airflow and heat transfer have been obtained. The results show that the trend of the ground temperature variation in different months is the same and the maximum value of it has always occurred at 1 pm. In addition, in all the hours and months that examined in the present study, the natural convection for the fluid flow than the forced convection is insignificant, and the main of the fluid flow and pollutants is due to the wind velocity at the inlet boundary condition and the pollutants velocity. In cases with higher windward wall and small aspect ratio between buildings and street, the lowest pollutant concentration in passengerchr('39')s level is achieved.

The inverter is one of the main components of photovoltaic power plants. Since the power output of the power plant is directly related to the inverter's performance, the inverter losses have an important effect on the generation and efficiency of the photovoltaic plant. The most important of inverter losses are the inverter clipping and inverter efficiency losses. Some factors affecting clipping losses and inverter efficiency are the sea surface height, ambient temperature, input power DC, wind speed, air density, radiation, and so on. Due to the high radiation potential, the wide area, and the variety of climate in Kerman province, in this article, Kerman province has been selected for the installation of photovoltaic power plants and the effects of environmental factors on inverter clipping losses and inverter efficiency are studied in different areas of Kerman. In simulating the effects of several factors such as wind speed, radiation, altitude, ambient temperature, wiring losses, inverter power consumption during operation and at the night, shadow and dust losses are considered. In addition, the effect of the inverter DC to AC ratio on the inverter clipping losses, power generation capacity, and on the capacity factor of photovoltaic plant have been investigated.