Showing 3 results for Chitsaz Khoyi
Parisa Mojaver, Shahram Khalilarya, Ata Chitsaz Khoyi,
Volume 18, Issue 3 (5-2018)
Abstract
In the present study, a novel integrated system containing biomass gasifier, sodium high-temperature heat pipes, and solid oxide fuel cells is introduced. The integrated system is taken into consideration due to its high efficiency and power in order to simultaneous producing electrical power and heat. The modeling of system is performed using equilibrium constants, mass and energy conservation law and the analysis of codes is done in EES software. The effect of gasifier STBR, current density, fuel utilization factor, and outlet fuel cell’s temperature as variable parameters is investigated on the power and total energy efficiency of integrated system using response surface method; after validation of modeling in comparison to the experimental results. The analysis of variance results indicate that fuel utilization factor (with 53% contribution) and current density (with 33% contribution) are the most effective parameter on the power and total efficiency, respectively. The power of integrated system is increased by increasing of temperature while power has an increasing behavior follows by decreasing behavior by increasing fuel utilization factor. The total efficiency is increased by increasing temperature and STBR while it is decreased by increasing current density and fuel utilization factor. The results revealed that the power and total efficiency is obtained at optimum states as high as 300 kW and 90%, respectively.
Naghi Aghazadeh, Shahram Khalilarya, Samad Jafarmadar, Ata Chitsaz Khoyi,
Volume 18, Issue 7 (11-2018)
Abstract
In this article, a new power, cooling and heating cogeneration system consisting of a solid oxide fuel cell (SOFC) - gas turbine (GT), a heat recovery steam generator (HRSG), Generator-Absorber-heat eXchange (GAX) absorption refrigeration cycle and a heat exchanger for heat recovery (HR) has been studied from a thermodynamic and economic perspective. The modeling of this cycle was done by solving the electrochemical, thermodynamic and exergoeconomic equations for fuel cell and system components, simultaneously. The results showed that the exergy of our proposed combined cycle is 14.9% more and the irreversibility rate of this cycle is 10.6% less than that of the combined SOFC-GT-GAX systems in the same conditions. Also, the fuel cell and the afterburner have the highest rate of exergy destruction among other components due to irreversibility. Exergoeconomic analysis showed that the sum of uint cost of products (SUCP), the exergoeconomic factor, the capital cost rate and the exergy destruction cost rate for the overall system is equal to 331.1 $/GJ, 29.3%, 10.47 $/h and 25.32 $/h, respectively. Parametric studies showed that increasing the current density will increase the net electrical power, heating capacity of HRSG and HR heat exchanger, cooling capacity and total irreversibility. Also, with increasing of the current density, both the exergy efficiency and SUCP decrease.
M. Abdollahi Haghghi, S.m. Pesteei , A. Chitsaz Khoyi,
Volume 19, Issue 2 (February 2019)
Abstract
In this paper, a study from the perspective of exergy and cost in the framework of exergoeconomic analysis of a heating and power generation system with parabolic trough solar collectors was carried out as a case study to be used at the engineering faculty of Urmia University. The system consists of a solar subsystem with an Organic Rankine Cycle (ORC). This study is based on three different solar radiation modes during a day, including solar mode, solar and storage mode, and storage mode. In the first mode, the solar flux is at a low level and there is no energy storage. In the second mode, there is energy storage in addition to running the ORC by collectors. In the third mode, only storage tank is used. Paying attention to the actual energy demand of the location and the analysis according to the variable solar radiation are the important points of this study. Due to the weather conditions prevailing on the building, its heating load is 1253.2kW. Also, the electric power required is about 1500kW. Exergoeconomic analysis is based on three important design parameters, including the number of the day through the year, ORC pump input temperature, and ORC turbine inlet pressure examined. The results indicate that in a cold day, the cost per unit of exergy in the three mentioned modes are about 19$/GJ, 16$/GJ, and 20$/GJ, respectively. Also, the highest exergy destruction rate occurs in parabolic trough solar collectors and ORC evaporators.
