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, thermodynamic modeling and simulation of the proposed system have been done to evaluate the performance of the integrated system. Also, exergetic, exergoeconomic and advanced exergetic analysis has been performed for the proposed system. The analysis of the integrated system has been carried out by using MATLAB code. Verification of thermodynamic simulation has been performed with high accuracy. Results of thermodynamic simulation show that the net power and overall cycle efficiency of the proposed cycle are increased by 1.1 MW and 7.7 % respectively rather initial SOFC-GT combination. The exergy analysis indicated that exergy efficiency is 40.95%, for the proposed system and 37.3% for the initial base case. As a result, the exergy destruction, exergoeconomic factor, cost rate per exergy unit of product and fuel, and cost rate associated with the exergy destruction for each component are calculated and evaluated. Also, endogenous/exogenous and avoidable/unavoidable parts of exergy destruction, exergy destruction costs, and capital costs have been determined and compared.
In this study, an integrated structure of the air separation unit, natural gas liquids recovery equipped with nitrogen removal unit is developed. In this regard, advanced exergy and exergoeconomic analyses are used to examine the irreversibility, possible improvements and the cost of the inefficiencies of the process. The exergy analysis presents information on the origin of the irreversibility as well as the amount of irreversibility of each component. The results of advanced exergy analysis show that HX2, HX3, C1, C2, C3, AC1, AC3 equipment have the highest amount of the irreversibility due to endogenous exergy destruction, whereas the highest amount of the irreversibility in the rest of the equipment is because of exogenous exergy destruction. Furthermore, avoidable exergy destruction of equipment is more than the unavoidable exergy destruction in the C1, C2, and C3. This issue shows that with the improvement of the efficiency of the equipment, it is feasible to reduce the irreversibility of these systems. In addition, the results of advanced exergoeconomic analysis show that the priority to improve the performance of the system should be devoted to the HX2, HX3, C1, C3, AC1, AC3 equipment, respectively. The AC1 air cooler and the C3 compressor have the highest amounts of investment cost of avoidable endogenous exergy destruction, respectively. The heat exchanger HX3 and air cooler AC2 and AC3 have the lowest investment cost of avoidable endogenous exergy destruction.
Simulation and Computational Fluid Dynamic (CFD) analyses of condensing shell and tube heat exchanger is subjected in this article. The condensing model using a User Defined Function (UDF) through Ansys Fluent 18.2 is developed. Also, the heat transfer between the shell and tube bundles is considered too. The subjected heat exchanger included seven tubes with a length of 600 mm and a shell with a diameter of 90 mm. The effect of different types of baffles and the distance between them is investigated in this article. All the calculations were done in three different mass flow rates. Finally, the distribution of heat flow is depicted for each stage of the considered heat exchanger. Results show that for the specific geometry and constant distance between baffles, increment in the mass flow rate leads to increasing the heat transfer coefficient. In addition, it shows that the formation of dew droplets and condensed water is higher in the first geometry due to the maximum heat transfer by hot flue gas.