The paper illustrates some aspects of energy conversion processes during underground electric train operation. Energy conversion processes are explained using exergy, in order to support transport system sustainability. Loss of exergy reflects a loss of potential of energy to do work. Following the notion that life in Nature demonstrates sustainable energy conversion, we approach the sustainabi...

Exergy and thermoeconomic analyses are herein employed to evaluate the proposed refrigeration cycle of Tabriz olefin plant. The exergetic and exergoeconomic variables of all equipment and streams are calculated. Thermoeconomic model is developed according to the total revenue requirement (TRR) method. The results indicate that the rational efficiencies of the Heat Exchanger E-104 and compressor...

The objective of this paper is to describe several figures of merit for estimation of loss in work potential based on the second law of thermodynamics and to evaluate their relative merits for propulsion system analysis and design. The loss figures of merit examined are exergy, gas horsepower, stream thrust, and thrust work potential. Definitions and simplified expressions for evaluating each a...

utilization of fossil fuel for supplying of requires energy of desalination systems is common. on the other hand, solar energy is one of the high-grade energies in the world that can be found specifically in hot weather places. therefore, utilization of solar energy for operation of desalination systems will reduce greenhouse gases and is a good alternative way. common exergy analysis method (s...

Heating, cooling and lighting appliances in buildings account for more than one third of the world’s primary energy demand. Therefore, main components of the building heating systems play an essential role in terms of energy consumption. In this context, efficient energy and exergy utilization in HVAC-R systems has been very essential, especially in developing energy policies towards increasing...

LNG (Liquefied Natural Gas) shares in the global energy market is steadily increasing. One possible application of LNG is as a fuel for transportation. Stricter air pollution regulations and emission controls have made the natural gas a promising alternative to liquid petroleum fuels, especially in the case of heavy transport. However, in most LNG-fueled vehicles, the physical exergy of LNG is ...

The evaluation of ecosystem health is a fundamental process for conducting effective ecosystem management. Ecological exergy is used primarily to summarize the complex dynamics of lotic ecosystems. In this study, we characterized the functional aspects of lotic ecosystems based on the exergy and specific exergy from headwaters to downstream regions in the river’s dimensions (i.e., river width a...

Second-law analysis (SLA) is an important concept in thermodynamics, which basically assesses energy by its value in terms of its convertibility from one form to another. Highly-valued forms of energy in this context are called exergy, defined as those energies from which the maximum theoretical work is obtainable when the energy is interacting with the environment to equilibrium (see Moran et ...

The aim of the present paper is to examine the effect of ambient temperature on the performance of a combined cycle power plant. For this work, the combined cycle plant chosen is NTPC (National Thermal Power Corporation) Dadri, India where a gas unit of 817 MW is installed. The effect of ambient temperature on combined cycle efficiency, gas turbine cycle efficiency, exergy destruction in differ...

The impulse turbo expander (ITE) is employed to replace the throttling valve in the vapor compression refrigeration cycle to improve the system performance. An improved ITE and the corresponding cycle are presented. In the new cycle, the ITE not only acts as an expansion device with work extraction, but also serves as an economizer with vapor injection. An increase of 20% in the isentropic effi...