TJ1037 : Optimization and analysis of thermodynamic and economic performance of a hybrid system including Heliostat, Organic Rankine cycle and absorption chiller system
Thesis > Central Library of Shahrood University > Mechanical Engineering > MSc > 2025
Authors:
[Author], [Supervisor], [Supervisor]
Abstarct: Given the escalating global energy demand, the need for multi-purpose, sustainable, and efficient power generation systems utilizing renewable sources has become increasingly imperative. In this research, a novel system for electricity generation and cooling, baxsed on concentrated solar power (CSP tower technology) with hybrid thermal storage (phase change material (PCM) and molten salt), was proposed. The topping cycle was selected as the supercritical CO₂ recompression Brayton cycle (sCO₂ recompression Brayton cycle), and its excess heat was distributed in parallel between the bottoming parallel two-stage organic Rankine cycle (Parallel Two-stage Organic Rankine Cycle - PTORC) with R245CA as the working fluid and the ammonia-water absorption refrigeration cycle (Ammonia-water Absorption Refrigeration Cycle - ARC). This configuration was designed to achieve maximum waste heat recovery, enhance overall efficiency, and enable simultaneous production of additional power and cooling. Multi-objective optimization was performed using the non-dominated sorting genetic algorithm II (NSGA-II) in the MATLAB environment. The optimization objectives were to maximize the overall energy efficiency of the system and minimize the total cost rate. Decision variables included the sCO₂ cycle pressure ratio, PTORC evaporator temperatures, pinch temperature differences, and superheat degrees. Pareto front points were selected using TOPSIS and LINMAP methods, revealing a significant superiority of the PTORC configuration over the simple ORC. Thermodynamic and exergy analyses indicated a reduction in irreversibilities facilitated by the two-stage PTORC. Technoeconomic analysis demonstrated that the levelized cost of electricity (Levelized Cost of Electricity - LCoE) is 0.1 $/kWh, placing it at the lower end of the global CSP trend range (baxsed on the IRENA 2024 report). The discounted payback period (Discounted Payback Period - DPP) for PTORC is approximately 7.11 years, representing a reduction of about 6 months compared to the simple ORC, while the net present value (NPV) at the end of the 20-year lifespan is positive and profitable.
Keywords:
#Concentrated Solar Power (CSP) #Supercritical CO₂ Cycle(SCO2) #parallel double cascade-evaporator organic Rankine cycle (PTORC) #Multi-Objective Optimization #Techno-Economic Analysis Keeping place: Central Library of Shahrood University
Visitor: