Cogeneration power plants simultaneously generate power and usable heat in a single, integrated system, which achieves a degree of overall efficiency that is much greater compared to electricity production alone. This makes better use of energy conversion and reduces greenhouse gas emissions. Combined heat and power production is already relatively common in Europe while it is less common, for ...

This paper is devoted to study the effects of pressure drop in heat exchangers on the dynamics of a free piston Stirling engine. First, the dynamic equations governing the pistons as well as the gas pressure equations for hot and cold spaces of the engine are extracted. Then, by substituting the obtained pressure equations into the dynamic relationships the final nonlinear dynamic equations gov...

in this paper the numerical analysis of flow and time dependent heat transfer of micro-tube conveying nanofluid in laminar flow is investigated. in this study, convection heat transfer of nanofluid and base fluid and transient analysis for time-varying heat flux for time step of 0.0001 second are elucidated. it is observed that the pumping power of nanofluid flowing and the maximum temperature ...

Power semiconductors can be modeled as a thermal network of resistors and capacitors. The thermal boundary condition of such a model is typically defined as the heat sink surface temperature which is assumed to be constant. In reality, the heat sink surface temperature underneath the power module is not exactly known. In this paper we show how to set up a thermal model of the heat sink in form ...

In this study, heat release performances of the three extruded-type heat sinks can be used in inverter for solar power generation were evaluated. Numbers of fins in the heat sinks (namely E-38, E-47 and E-76) were 38, 47 and 76, respectively. Heat transfer areas of them were 1.8, 1.9 and 2.8m. The heat release performances of E-38, E-47 and E-76 heat sinks were measured as 79.6, 81.6 and 83.2%,...

Low transmission of heat is one of the major problems for heat exchanger fluids in many industrial and scientific applications. This includes cooling of the engines, high power transformers to heat exchangers in solar hot water panels or in refrigeration systems. In order to tackle these problems in thermal industries, nanofluids could play a significant role as excellent heat exchanger materia...

The present study investigated the effect of distilled-water/ silver nanofluid on heat transfer in a closed cooling system of one of the electrical energy generation units at Isfahan power plant. The difference between this study and previous researches refers to silver properties which have a high thermal conductivity and is non-toxic, hydrophilic and eco-friendly. Distilled water/ silver ...

In the provinces of north China, combined heat and electric power generations (CHP) are widely utilized to provide both heating source and electricity. While, due to the constraint of thermal-electric coupling within CHP, a mass of wind turbines have to offline operate during heating season to maintain the power grid stability. This paper proposes a thermal-electric decoupling (TED) approach to...