## 1 Introduction
They recovered the waste heat of the system through Rankine cycles and produced more power by its expanders. The obtained energy and exergy efficiencies of the suggested integrated system were \(58.78\%\) and \(50.66\%\), respectively. [PERSON] et al. [20] proposed a system of combined ammonia recovery and SOFCs for wastewater treatment plants and modeled it using Aspen Plus V.8.8. The results showed an increase of \(45\%\) in renewable electricity production, thereby achieving a \(6\%\) reduction in consumption and an annual reduction in GHG emissions of \(3.4\) kg CO\({}_{2}\) per person. [PERSON] et al. [21] designed a combined heat, hydrogen, and power system using ammonia as fuel for SOFCs to generate hydrogen at \(100\) kg/day via two different concepts. An analysis of the trigeneration efficiencies demonstrated that the two designed concepts achieved \(81\%\) and \(71\%\). [PERSON] et al. [22] investigated a SOFC-Brayton cycle-Rankine cycle combined system to improve the efficiency and power generation of the system. The six working fluids used for the ORC were R123, R245 fa, benzene, cyclohexane, toluene, and cyclopentane. The achieved energy and exergy efficiencies were \(64\%\) and \(62\%\), respectively, and the efficiency improved by approximately \(34\%\) compared to the base gas turbine cycle. [PERSON] and [PERSON] [17] analyzed the energy and exergy efficiencies of an SOFC system using ammonia as fuel. The total exergy efficiency of the system, as a function of the current density, was \(60\)-\(90\%\), while the energy efficiency varied from \(60\%\) to \(40\%\). A survey of the existing literature and research shows that there is a lack of comprehensive studies and analyses on the integration of the SOFC and gas turbine (GT) bottoming cycle employing ammonia as fuel for marine applications. To fill this knowledge gap in the literature, the precise objectives of this study are as follows:  
* To develop the novel integrated SOFC-GT-Rankine cycles-KC system using ammonia as a fuel. To analyze the energy and exergy efficiencies of the proposed system from a thermodynamic point of view. To conduct parametric studies to determine the reaction of this system to a variety of different circumstances. The novel aspects of this study are as follows:  
Usage of ammonia as ship fuel. Application of an integrated SOFC-based system for shipping vessels. The influence of the current density on the efficiency of SOFC and the integrated system. Usage of waste heat from an SOFC-GT hybrid system increases the thermal efficiency of the system. The estimation of energy and exergies efficiencies, the exergy destruction of main components of proposed system. Parallel integration of GT with cascaded Rankine cycles and KC to generate additional power for accommodation, lighting, auxiliary machinery and other purposes. The selection method for most suitable working fluid for optimize operation of the organic Rankine cycle. The next structure of the current study is organized as follows. Section 2 explains the background of ammonia-fueled SOFCs and energy systems for power generation, and introduces the proposed combined heat and power (CHP) system. Section 3 evaluates each system section from a thermodynamic viewpoint and builds up the energy and exergy calculation model for each subsystem. Section 4 outlines the assumptions, methodology, and procedures used in this study. The model is verified in Section 5. The numerical modeling approach, results of this study in terms of energy and mass balances, and overall CHP performance, are presented in Section 6. The conclusions are presented in Section 7.