during the last years the total cost of lng technology has decreased significantly due to improvements of the liquefaction process. however, many liquefaction plants that are still in operation use a three-cascade refrigeration system. in this paper, an advanced exergetic analysis is applied to better understand the operation of a three-cascade refrigeration system for liquefaction of natural g...

With multiple primary and secondary energy converters (diesel engines, steam turbines, waste heat recovery (WHR) and oil-fired boilers, etc.) and extensive energy networks (steam, cooling water, exhaust gases, etc.), ships may be considered as complex energy systems. Understanding and optimizing such systems requires advanced holistic energy modeling. This modeling can be done in two ways: The ...

Due to the necessity of using highly efficient power generation systems to reduce fuel consumption and air pollution, the integration of different energy systems is promising modification to achieve higher efficiency. In this paper, the integration of an Internal Reforming Solid Oxide Fuel Cell (IRSOFC)-Gas Turbine (GT)-Organic Rankine Cycle (ORC) system has been proposed. In this regard, therm...

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...

TThe present paper evaluates the plan of combustion air pre-heater installation on the fired heater from thermodynamics and thermos-economics point of view. As a real case study, one of the fired heaters (H_101) of Distillation unit in Tehran Oil Refinery, Iran, is intended. With applying an air pre-heater in this study, flue gases temperature falls down from 430 ºC to 200ºCand combustion a...

The objectives of this study are to (a) evaluate the exergy and energy demand for constructing a hydrofractured shale gas well and determine its typical exergy and energy returns on investment (ExROI and EROI), and (b) compute the gas flow and intrinsic exergy analysis in the shale gas matrix and created fractures. An exergy system analysis of construction of a typical U.S. shale gas well, whic...

In order to evaluate and improve the performance of a ground-coupled heat pump (GCHP) heating system with radiant floors as terminals, an exergy analysis based on test results is performed in this study. The system is divided into four subsystems, and the exergy loss and exergy efficiency of each subsystem are calculated using the expressions derived based on exergy balance equations. The avera...

To understand ecological systems and environmental impact, techniques can be used which combine thermodynamics with environment and ecology. Most assessments consider thermodynamics via energy, but it many feel that ecological and environmental factors are better understood through exergy. One rationale is that exergy, not energy, is often a measure of the potential for ecological and environme...