فهرست مطالب morteza saadat-targhi

Nowadays, the use of thermoelectric as one of the methods of recovering waste heat energy has received much attention. In this research, while presenting a new thermal energy recovery system in the molten slag of steel Industry, thermodynamic analysis of the proposed system from the perspective of energy and exergy is also presented. Then the effect of various parameters including Seebeck coefficient on the performance of the proposed system is investigated. The results of modeling in both power cycle and thermoelectric cycles have been validated by previous research. The results of thermodynamic analysis show that the largest contribution to the exergy destruction of the proposed system is related to the heat recovery system. According to the results, the production capacity of the heat recovery system from the total production capacity is about 49% and the efficiency of the first law of thermodynamics for the proposed system is 24.7% and the efficiency of the second law of thermodynamics is 32.88%. Economic analysis indicates that with thermoelectric generator cost of 1 $/W the payback rate of investment is less than 2 years.

The fast filling process is the main process that occurs in the CNG refueling station. The main objective of the present study is to apply a thermodynamic analysis for a complete modeling of a CNG refueling station with several consecutive refueling . The results of the thermodynamic analysis have been validated against the experimental data and previous studies. The AGA8 Equation of State has been used to calculate the thermodynamic properties of CNG. There are many researches concentrated on the thermodynamic modeling of CNG refueling station, but didn't address the optimal algorithm of priority panel. Filling time minimizing, filling mass maximizing and average specific energy consumption minimizing have been employed as the objective function for the optimization problem. Finally, the optimal algorithm of priority panel has been determined as the main goal of the present study. The conclusive results of the optimization problem are presented. Achieving more accurate modeling and modeling the process of several consecutive refueling is one of the most important results of the present study. The optimal algorithm of priority panel are obtained for PPM225 algorithm . An economic analysis is performed to see the results more clearly. The results of the economic analysis show that 65,700,000,000 Rials (43,800,000 kWh) can be saved in one year.

In this paper, the optimal combined organic Rankine-vapor compression cycle is proposed to produce cold water for hospital air conditioning using solar energy. The hospital is located in Esfarayen city and the intensity of solar radiation in all months is calculated. The results show that in the five months of May, June, July, August and September, there is the highest solar radiation in Esfarayen city. The possibility of using daily solar radiation to produce cold water during these five months is examined. Simulation is performed using the Engineering Equation Solver (EES) software. Six refrigerants R22, R134a, R600, R143a, R500, and R11 are considered as working fluids for the cycle and based on energy and exergy analysis, suitable fluid is recommended for this system. The effects of solar radiation, refrigerant, and mass flow rate of the refrigerant on the cooling water temperature outlet from the evaporator, cycle performance, organic Rankin cycle efficiency, performance coefficient of the VCC cycle, and exergy efficiency of the ORC-VCC system are investigated. The results show that using the refrigerant R22 is more suitable than other refrigerants because the cycle with this refrigerant reduced the water temperature up to 8 o C in the evaporator, as well as the cycle performance are obtained 0.72 and organic Rankin cycle efficiency is 13.9%, which will be the highest. The results show that increasing boiler thermal energy (solar radiation) reduces water temperature in the evaporator and exergy efficiency of the system, and increases organic Rankin cycle efficiency and cycle performance.