the aim of this study is to find the optimal water pressure and percentage of supply vapour in the feed water heaters (fwhs) of steam power plants, such that they maximize the thermal efficiency of the rankine cycle within pre-specified values of minimum and maximum pressures of the thermodynamic cycle. thermal efficiency is defined as a function of unknown variables (fluid pressure and vapour ...

Since free Stokesian swimming does no work external to fluid and body, the classical thermodynamic efficiency of this activity is zero. This paper introduces a potential thermodynamic efficiency by partially tethering the body so that work is done externally and instantaneously. We compare the resulting efficiency with other definitions utilized in Stokes flow, extend the instantaneous definiti...

Pumped heat electricity storage (PHES) has been recently suggested as a potential solution to the large-scale energy storage problem. PHES requires neither underground caverns as compressed air energy storage (CAES) nor kilometer-sized water reservoirs like pumped hydrostorage and can therefore be constructed anywhere in the world. However, since no large PHES system exists yet, and theoretical...

In this work, a clear distinction is drawn between irreversibility associated with a finite mean driving force in a transport process and irreversibility associated with variance in the spatial and/or temporal distribution of this driving force. The portion of irreversibility associated with driving force variance is quantified via a newly defined dimensionless quantity, the equipartition facto...

Heat recuperation is often used to improve the overall cycle efficiency of gas turbines. However, generally in small- scale gas turbines, it has a negative effect on turbine inlet temperature, pressure ratio and pressure drops, and thus decreases the overall cycle efficiency. In this paper, a thermodynamic model is performed to evaluate recovered heat as a function of heat exchanger effecti...

Heat recuperation is often used to improve the overall cycle efficiency of gas turbines. However, generally in small- scale gas turbines, it has a negative effect on turbine inlet temperature, pressure ratio and pressure drops, and thus decreases the overall cycle efficiency. In this paper, a thermodynamic model is performed to evaluate recovered heat as a function of heat exchanger effectivene...

The, submaximal, thermodynamic efficiency of aerobic microbial growth depends on whether no consumption / production of 02, or no carbon product other than biomass, is admitted into the assimilation equation. When the growth substrate has a low degree of reduction, the former efficiency approaches 22 % whilst the latter approaches 54 %. Expectations for maximal growth rate at optimum efficiency...