this study represents effect of four variables in performance of a heat-pump in two cities of tehran and rasht. a computer program has been developed, simulating a certain heat pump acting in different environments with different refrigerants in heating season. the analysis is based on a homogeneous model. effect of different refrigerants, depth of the buried heat exchangers and moisture conten...

In this case study, exergy analysis is applied to a mini two-shaft gas turbine which is located in Islamic Azad University Khomeini Shahr Branch`s Thermodynamics laboratory and a proposal presented to make exergy destruction less using a Heat Recovery Water Heater (HRWH). Calculations were done for N2=20000 (rpm) constant and various N1 and after that for N1=600...

Gas turbine power can be augmented by overspray process which consists of inlet fogging and wet compression. In this study exergy analysis of the overspray process in gas turbine system is carried out with a non-equilibrium analytical modeling based on droplet evaporation and the second law of thermodynamics. This work focuses on the effects of system parameters such as pressure ratio, water in...

exergy analysis of a system is a method for recognizing the value and type of system availability against surrounding environment. it also helps to find how macroscopic properties of the system change during a process. this analysis is based on first and second laws of thermodynamics. by exergy analysis proportion of each process in the internal availability transmission and the places of usefu...

Exergy concepts and exergy based methods offer an insight to the understanding of sustainable energy engineering. The utilization of energy and other resources by applying physical concept as exergy and exergy based methods and the value of these tools in the design are presented, in particular Life Cycle Exergy Analysis (LCEA). LCEA is applied to a typical wind power plant. This brings a new a...

A shower cooling tower (SCT) operates without fill because of salt decomposition on the fill that leads to deterioration of conventional cooling tower performance. This study presents a two-dimensional mathematical model for energy and exergy analysis of multi-diameter droplets and air interaction along with the height of the forced draft SCT, to predict the exit condition of water droplet for ...

The location of heat transfer pinch point in evaporator is the base of determining operating parameters of organic Rankine cycle (ORC). The physical mathematical model seeking the location of pinch point is established, by which, the temperature variations both of heat source and working fluid with UA can be obtained. Taking heat source with inlet temperature of 160 C as example, the matching p...

In this study, a four stroke four cylinder direct injection CI engine was run using three different injection pressures. In all measurements, the fuel quantity per cycle, the pre injection and main injection timing, the boost pressure and the engine speed were kept constant. The motor tests were performed under 130, 140 and 150 MPa rail pressure. During the theoretical part of the study, combus...