The present paper describes the energy and exergy analysis of a reheat regenerative vapor power cycle. The plant consists of one boiler feed pump, one supercritical boiler, two steam turbines with a reheater in between, two feed water heaters (one open and one closed) and a condenser. The energy and exergy balance study has been carried-out for each component of the plant. Energy efficiency, ex...

The analysis of complex thermodynamic systems with exergetic and 2nd law methods is continually performed for various fields of engineering. This also applies to environmental control systems (ECS) of aircraft. This paper focuses on methods of exergy and energy analysis applied to ECS. It gives a survey of the published material and identifies the state of the art. Furthermore, this analysis in...

Cogeneration may be defined as a system which contains electricity production and regain of the thermo value of exhaust gases simultaneously. The examination is based on the data’s of an active cogeneration plant. This study, it is aimed to determine which component of the system should be revised first to raise the efficiency and decrease the loss of exergy. For this purpose, second law analys...

Several fundamental concepts with respect to the second-law analysis (SLA) of the turbulent flows in gas turbines are discussed in this study. Entropy and exergy equations for compressible/incompressible flows in a rotating/non-rotating frame have been derived. The exergy transformation efficiency of a gas turbine as well as the exergy transformation number for a single process step have been p...

Abstract: The evaluation of the thermodynamic performance of the mutual transformation of different kinds of exergy linked to the intensive thermodynamic parameters of the flow inside the ejector of a refrigeration system is undertaken. Two thermodynamic metrics, exergy produced and exergy consumed, are introduced to assess these transformations. Their calculation is based on the evaluation of ...

Every developed and adapted biological system extracts useful energy from outside, converts, stores it, and uses for muscular contraction, substrate transport, protein synthesis, and other energy utilizing processes. This energy management in a living cell is called the bioenergetics, and the useful energy is the exergy, which is destroyed in every irreversible process because of the entropy pr...

The paper addresses the problem of the existence and quantification of the exergy of non-equilibrium systems. Assuming that both energy and exergy are a priori concepts, the Gibbs “available energy” A is calculated for arbitrary temperature or concentration distributions across the body, with an accuracy that depends only on the information one has of the initial distribution. It is shown that ...

The benefits are demonstrated of using exergy to understand the efficiencies of electrical power technologies and to assist improvements. Although exergy applications in power systems and electrical technology are uncommon, exergy nevertheless identifies clearly potential reductions in thermodynamic losses and efficiency improvements. Various devices are considered, ranging from simple electric...

In this study, the first and the second laws of thermodynamics (exergetic analysis) are used to analyse the performance of a single stage ammonia-water absorption cooling system operating under different working conditions. In this analysis, the performance of the system is simulated under various operating temperatures: the condenser and absorber (30 and 40°C), evaporator (-10°C, 0°C and +10°C...

An energy flow model of an airport terminal’s HVAC system is established in this paper. Based on energy flow model, the exergy efficiency, exergy loss and exergy cost distribution ratio of each component are calculated and analyzed by the energy flow model. Optimization method and exergy balance equations are used to calculate the lowest exergy loss of HVAC system under different operation cond...