Two models based on Li et al. (2011) are developed for general application in estimating the monthly average daily diffuse solar radiation in China. The validation of these models is performed by comparing with four existing empirical models against the measured data. It is found that the...

The objective of this study is to demonstrate the feasibility of acquiring geothermal energy from existing abandoned oil and gas wells. The equations describing the heat exchange between fluid and rocks are developed, and parametric studies are conducted in order to specify the optimum values of...

There are many solar constant values given and adopted by researchers, leading to confusion in estimating solar radiation. In this study, some solar constant values collected from literature for estimating solar radiation with the Ångström–Prescott correlation are tested in China using the...

Eight models using only the sunshine duration for estimating the global solar radiation on a horizontal surface are evaluated at Changdu, Geer, Lasa and Naqu stations in Tibet, China against the measured meteorological data during 1994–2008. Based on statistical error tests, results show that...

With a constant-pressure mixing ejector, the performance characteristics of an ejector-expansion refrigeration cycle (EERC) using R1234yf as refrigerant have been investigated. Also, the performance of R1234yf and R134a in the EERC has been compared. The study shows that, at condensing...

Solar radiation measurements are not easily available, especially for the diffuse solar radiation. In this study, two models for estimating the diffuse solar radiation are proposed based on multiple predictors including the clearness index, relative sunshine duration, ambient temperature and...

In this study, a new empirical model is proposed for estimating daily global solar radiation on a horizontal surface by the day of the year. The performance of the proposed model is validated by comparing with three trigonometric correlations at nine representative stations of China using...

In the present study, the photon absorption in a suspended photocatalytic reactor was simulated by adopting Monte Carlo method and the six-flux radiation absorption-scattering model. Different photocatalyst concentrations, i.e. uniform concentrations, linearly increasing concentration gradients...

One of the greatest problems in using renewable energy sources is the great variability of energy level, both in the short and long term. Geothermal energy, by nature, has high availability because the source is not dependent on weather conditions, so it is among the most stable renewable energy...