nowadays, energy plays an important role in the economic and community development of country. consequently, performance analysis of energy systems is one of the effective methods being used to prevent waste of energy resources. among the different power generation technologies, steam power plants make a significant contribution to power generation in iran, with a share of 47 % of electricity g...

heat and mass transfer, in this paper, is considered in one-row heat exchanger, that fins are hotter than air flow and water is added to fins. related governing equations are derived by analyzing a two-dimension model in a unique cell of a heat exchange. these equations are numerically solved by finite difference method. heat transfer and efficiency under partially wet surface are calculated by...

Photovoltaic (PV) modules and solar thermal collectors are convectional solar systems that convert solar radiation into electricity and heat energy respectively. PV modules generate clean electricity and ideal for use in developing countries where human settlement is scattered in remote rural areas and no grid electricity is available. However, electrical conversion efficiency of commercial PV ...

Temperature rising is a negative factor in almost all systems. It could cause by self heating or ambient temperature. In solar photovoltaic cells this temperature rising affects on the behavior of cells. The ability of a PV module to withstand the effects of periodic hot-spot heating that occurs when cells are operated under reverse biased conditions is closely related to the properties of the ...

introduction electrical performance of solar cells decreases with increasing cell temperature, basically because of growth of the internal charge carrier recombination rates, caused by increased carrier concentrations. hybrid photovoltaic/thermal (pvt) systems produce electrical and thermal energy simultaneously. pvt solar collectors convert the heat generated in the solar cells to low temperat...

To successfully implement a packaging concept, it is imperative to resolve many challenging issues related to materials and processing, which will result in improved thermal management of the power electronics modules. Almost every parameter of a power device is a function of temperature. The heat generated by these active devices, which reduces circuit efficiency, may also degrade circuit perf...

Isolated carbon nanotubes (CNTs), CNT films and CNT-polymer nanocomposites are a new generation of materials with outstanding mechanical, thermal, electrical and electromagnetic properties. The main objective of this article is to provide a comprehensive review on the investigations performed in the field of characterizing electrical and electromagnetic properties of isolated CNTs and CNT-reinf...

Thermoelectric materials have generated interest as a means of increasing the efficiency of power generation through the scavenging of waste heat. Materials containing nanometer-sized structural and compositional features can exhibit enhanced thermoelectric performance due to the decoupling of certain electrical and thermal properties, but the extent to which these features can be controlled is...

In this paper, the basic constitutive equations and equations of motion are derived to describe the behavior of thermoelastic porous piezoelectric medium by using Biot’s theory and the theory of generalized thermoelasticity with on relaxation time (Lord-Shulman). The electrical enthalpy density function is derived in the general coordinates. Also, clear definitions for the poroelastic modulus, ...

In this research work, numerical simulations are performed to correlate the photovoltaic parameters with various internal and external factors influencing the performance of solar cells. Single-diode modeling approach is utilized for this purpose and theoretical investigations are compared with the reported experimental evidences for organic and inorganic solar cells at various electrical and t...