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...

recent developments in hydrogen production by thermochemical water decomposition are reported,with an emphasis on hydrogen production from non-fossil energy sources such as nuclear and solar. numerousdevelopments have been made on sulphur-iodine, copper-chlorine and other thermochemicalcycles. efforts are described to lower the temperatures required in thermochemical cycles, so as to broadenthe...

This paper carries out a performance analysis based on the first and second laws of thermodynamics for heat recovery vapor generator (HRVG) of ammonia-water mixture when the heat source is low-temperature energy in the form of sensible heat. In the analysis, effects of the ammonia mass concentration and mass flow ratio of the binary mixture are investigated on the system performance including t...

In the past few years, resource use and resource efficiency have been implemented in the European Union (EU) environmental policy programs as well as international sustainable development programs. In their programs, the EU focuses on four resource types that should be addressed: materials, energy (or carbon dioxide [CO2] emissions), water, and land. In this article, we first discuss different ...

In this work, single-stage and two-stage tubular solid oxide fuel cell (SOFC)/gas turbine hybrid cycles are comparatively examined from the energy and exergy viewpoints. For this purpose, mass, energy and exergy balances are applied to all components of the cycles. The behavior of tubular solid oxide fuel cell modeled in this study is validated with the experimental test data of tubular SOFC de...

Abstract—In the current study, energy and exergy analysis of a 65 MW steam power plant was carried out. This study investigated the effect of variations of overall conductance of the super heater on the performance of an existing steam power plant located in Derna, Libya. The performance of the power plant was estimated by a mathematical modelling which considers the off-design operating condit...

The Relative Gain Array (RGA) provides a quantitative comparison of interactions between control loops. It shows steady state interactions between control loops. The thermodynamic concept of exergy can be used to analyse a process in terms of its efficiency. The Relative Exergy Array (REA) that measures both the relative exergetic efficiency and controllability of a process has been proposed (2...

We present analyses of three families of compressed air energy storage (CAES) systems: conventional CAES, in which the heat released during air compression is not stored and natural gas is combusted to provide heat during discharge; adiabatic CAES, in which the compression heat is stored; and CAES in which the compression heat is used to assist water electrolysis for hydrogen storage. The latte...

This paper analyzes the energetic and exergy performance of an active magnetic regenerative refrigerator using water-based Al2O3 nanofluids as heat transfer fluids. A 1D numerical model has been extensively used to quantify the exergy performance of a system composed of a parallel-plate regenerator, magnetic source, pump, heat exchangers and control valves. Al2O3-water based nanofluids are test...