In an attempt to improve the performance of hybrid absorption and mechanical vapor compression refrigeration systems and to determine the fundamental reasons for such improvements, two configurations of the hybrid refrigeration cycle with a booster compressor at different positions of the cycle (between the evaporation and the absorber, or between the generator and the condenser) are simulated ...

and Tribus, 1962), which is also named exergoeconomics (Bejan et al, 1996) and exergonomics (Yantovskii, 1994). The concept of utility is a central concept in macroeconomics. Utility is also closely related to exergy, and an exergy tax is an example of how exergy could be introduced into macroeconomics. This paper introduces and clarifies important concepts in the development of a sustainable e...

Cogeneration can improve energy utilization efficiency significantly. In this paper, a new ammonia-water system is proposed for the cogeneration of refrigeration and power. The plant operates in a parallel combined cycle mode with an ammonia-water Rankine cycle and an ammonia refrigeration cycle, interconnected by absorption, separation, and heat transfer processes. The performance was evaluate...

Exergy is applied to the Swedish energy supply system for the period 1970–2013. Exergy flow diagrams for the systems of electricity and district heating as well as for the total supply system of energy and material resources for 2012 are presented. The share of renewable use has increased in both electricity and district heat production. The resource use is discussed in four sectors: residentia...

Through online optimization and control, vapor compression systems (VCSs) can effectively respond to disturbances, such as weather or varying loads that cannot be accounted for at the design stage, while simultaneously maximizing system efficiency. However, to do so requires a mathematical characterization of efficiency for the VCS. In particular, we would like to maximize the exergetic efficie...

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...

since the energy analysis considers the quantity of energy, it cannot show the performance of the cooling tower. therefore, in order to optimize the performance of the tower and also the process which the cooling tower is a part of it, it is necessary to analyze the energy and exergy of the tower simultaneously. in this paper, the energy and exergy of one of the cooling towers of khuzestan stee...

Thermoeconomic models, which combine the concept of cost in the field of economics and the concept of exergy in the field of thermodynamics, provide a possibility of optimizing complex energy-generating systems to achieve a best balance between thermodynamic efficiency and economic cost (including investment cost and operation cost). For the first time, operation optimization on a 300 MW coal-f...

Refrigeration cogeneration systems which generate power alongside with cooling improve energy utilization significantly, because such systems offer a more reasonable arrangement of energy and exergy ‘‘flows’’ within the system, which results in lower fuel consumption as compared to the separate generation of power and cooling or heating. This paper proposes several novel systems of that type, b...