Lin Wenxian

Ratios of global radiation on a tilted to horizontal surface for Yunnan Province, China

Based on the dry-wet season model of solar radiation for Yunnan (DWS model) developed by us and relevant data on geographic and meteorological parameters, we have estimated values of global radiation on tilted surfaces (south-facing) for each month at 133 meteorological stations in Yunnan Province, China, and have studied the ratios of global radiation on tilted surfaces to those on horizontal surfaces based on estimated data at these stations. It is believed that the ratio patterns are similar to those in other regions of the world.

Distribution patterns of diffuse solar radiation in Yunnan Province, China

Abstract Yunnan Province, China, is situated in a very favorable region for solar energy utilization. Its unique “cubic climates” and geographic features make its distribution patterns of solar radiation vary considerably. It will be very beneficial to study, in detail, the characteristics of solar radiation climates in the province. Based on the correlations and the dry—wet season model of solar radiation for Yunnan developed by us, we present, in this paper, studies on the distribution patterns of diffuse solar radiation in the province.

Performance analysis of solar cell arrays in concentrating light intensity

Performance of concentrating photovoltaic/thermal system is researched by experiment and simulation calculation. The results show that the I–V curve of the GaAs cell array is better than that of crystal silicon solar cell arrays and the exergy produced by 9.51% electrical efficiency of the GaAs solar cell array can reach 68.93% of the photovoltaic/thermal system. So improving the efficiency of solar cell arrays can introduce more exergy and the system value can be upgraded. At the same time, affecting factors of solar cell arrays such as series resistance, temperature and solar irradiance also have been analyzed. The output performance of a solar cell array with lower series resistance is better and the working temperature has a negative impact on the voltage in concentrating light intensity. The output power has a −20 W/V coefficient and so cooling fluid must be used. Both heat energy and electrical power are then obtained with a solar trough concentrating photovoltaic/thermal system.

Correlations to estimate the monthly average daily diffuse radiation on horizontal surfaces in Yunnan Province, China

Abstract Yunnan Province, China, has its unique “cubic climates” which means that the climates in the region vary greatly. There are seven meteorological stations in the province which have measured data of global solar radiation on horizontal surfaces, and only four of them (Kunming, Tengchong, Hekou and Jinhong) have measured data of diffuse radiation on horizontal surfaces. With these data and the relevant data of the geographic and meteorological parameters of these four stations, we develop, in this study, two kinds of correlations to estimate the monthly average daily diffuse radiation on horizontal surfaces in Yunnan Province. It is believed that these correlations are applicable at any site in Yunnan Province.

Estimation and distribution patterns of direct solar radiation in Yunnan Province, China

Abstract Yunnan Province, China, is situated in a very favorable region for solar energy utilization. Its unique “cubic climates” and geographic features make its distribution patterns of solar radiation vary considerably. It will be very beneficial to study, in detail, the characteristics of solar radiation climates in the province. Based on the correlations and the dry—wet season model of solar radiation for Yunnan developed by us, we present, in this paper, studies on the estimation and distribution patterns of direct solar radiation in the province.

A numerical study on the unsteady evolution of weak axisymmetric fountain flows in a homogeneous ambient

Weak axisymmetrical fountains resulting from the injection of a dense fluid upwards into a large container of homogeneous fluid of lower density has been studied numerically in this paper using a time-accurate finite volume scheme. The behaviour of fountains for both the uniform and parabolic profiles of the discharge velocity at the fountain source has been investigated. The evolution of transient fountain flow has been analysed and two distinct stages of evolution have been identified. The time trace of the position of the fountain front has been presented and the initial, temporary and final fountain height and fountain width have been determined.