Although the cost allocation method does not change the total benefits of CHP, the use of various cost allocation methods generally results in significant differences in costs allocated for CHP products. In order to overcome the inadequacy of existing cost allocating methods in theory and in practice, according to the different roles of anergy and exergy in heat supply process of CHP plant, the...

This study presents comparative energy and exergy analyses of a single cylinder, four stroke Ruston diesel engine. The test was conducted by varying the load between zero and maximum while keeping the engine speed constant. Then, using the steady-state data along with energy and exergy balance equations, various performance parameters of the engine were measured. From the study it was found tha...

The current method used for calculating societal aggregated exergy efficiencies is reviewed. Cooling is introduced as an end-use category; conversion efficiencies for heating processes are obtained for each energy carrier; and electricity shares per end-use are retrieved for each sector, improving the accuracy of the estimated values of aggregated exergy efficiencies. We show that: (1) cooling ...

Combined heat and power systems are becoming more and more important, regarding their enhanced efficiency, energy saving, and environmental aspects. In the peresent study, three configurations of combined heat and power systems are intended as an alternative to separate production plant by considering environmental aspects. First and second laws of thermodynamics are adapted to the operatin...

introduction nowadays, due to higher environmental pollution and decreasing fossil fuels many countries make decisions to use renewable fuels and restrict using of fossil fuels. renewable fuels generally produce from biological sources. biodiesel is an alternative diesel fuel derived from the transesterification of vegetable oils, animal fats, or waste frying oils. considering the differences be...

The performance and design criteria of air powered multistage turbines are studied thermodynamically in this paper. In-house code is developed in the C++ environment and the characteristics of four-stage turbines with inter-heating are analyzed in terms of maximum thermal efficiency, maximum exergy efficiency and maximum work output over the inlet temperature range of 293 K–793 K with inlet pre...

The phrase ‘emergy baseline’ refers to the total yearly environmental support to the geobiosphere in terms of the emergy concept, and should include all three fundamental sources of exergy (i.e. sunlight, tidal exergy and deep earth heat). Ever since its introduction, the emergy baseline has undergone a continuous revision process, which, however, has so far focussed on the underlying equations...

The use of exergy to correlate energy-utilization efficiencies and energy research investments is described. Specifically, energy and exergy losses are compared with energy research and development expenditures, demonstrating that the latter correlates with energy losses, even though it would be more sensible to allocate energy research and development funding in line with exergy losses, as the...

In this study, an analysis of energy and exergy utilization in the utility sector of Jordan by considering the sectoral energy and exergy flows for the years 2007-2011 has been conducted based on real data obtained from main generators in Jordan. The overall energy and exergy efficiencies, for the entire utility sector, are found to be in the range of 35.1 to 38.1%. It is expected that the resu...

In this article, the first and second law analysis of diesel engine based cogeneration system was performed. Fuel utilization efficiency, rate of power, and rate of process heat of the plant were determined and various efficiencies based on both energy and exergy methods and the performance assessment parameters are defined for both the system components and the entire cogeneration plant. The o...