Search Results (3)

This research aims to assess the integration of different fuel cell (FC) options with battery and waste heat recovery systems through a mathematical modelling process to determine the most feasible retrofit solutions for a marine electricity generation plant. This paper distinguishes itself from existing literature by incorporating future cost projection scenarios involving variables such as carbon tax, fuel, and equipment prices. It assesses the environmental impact by including upstream emissions integrated with the Energy Efficiency Existing Ship Index (EEXI) and the Carbon Intensity Indicator (CII) calculations. Real-time data have been collected from a Kamsarmax vessel to build a hybrid marine power distribution plant model for simulating six system designs. A Multi-Criteria Decision Making (MCDM) methodology ranks the scenarios depending on environmental benefits, economic performance, and system space requirements. The findings demonstrate that the hybrid configurations, including solid oxide (SOFC) and proton exchange (PEMFC) FCs, achieve a deduction in equivalent CO₂ of the plant up to 91.79% and decrease the EEXI and the average CII by 10.24% and 6.53%, respectively. Although SOFC-included configurations show slightly better economic performance and require less fuel capacity, the overall performance of PEMFC designs are ranked higher in MCDM analysis due to the higher power density. Full article

This study proposes an innovative hybrid system that integrates a phosphoric acid fuel cell (PAFC) with an absorption refrigeration system (ARS) to enhance overall exergy efficiency. Waste heat from the PAFC is used in ARS generation. An evaluation is made of the energy efficiency, economic aspects, and the influence of the operating pressures of the two working fluid pairs, LiBr/H₂O and R134a/DMF. In the combined PAFC-ARS, the absorption refrigeration unit incurs the highest exergy loss: 157 kW (R134a/DMF) and 146 kW (LiBr/H₂O). The second-largest loss is experienced by the pure electrical generation PAFC unit at 117 kW. From an economic perspective, PAFC-ARS (LiBr/H₂O) systems incur costs of USD 2.4/t for both hot water and cooling water, and USD 0.13 kW/h for electricity, with an 8 year payback period. In comparison, the R134a/DMF system entails costs of USD 2.1/t for hot water and cooling water and USD 0.16 kW/h for electricity. The PAFC exhibits a net output power of 434 kW, considering both energy and exergy perspectives. The corresponding maximum net electric energy efficiency (η_I) of the PAFC is 52%, while the overall exergy efficiency of the cooling model (η_II,dc) of the PAFC-ARS peaks at 56%, and the overall exergy efficiency of the heating model (η_II,dh) reaches its maximum at 61%. In conclusion, the PAFC-ARS (LiBr/H₂O) demonstrates superior economic viability. Full article

Unlike a general commercial building, heating for a building with an indoor swimming pool is highly energy-intensive due to the high energy demand for swimming water heating. In Korea, the conventional heating method for this kind of building is to use boilers and heat storage tanks that have high fuel costs and greenhouse gas emissions. In this study, a combined heat and power (CHP) system for such a building using the electricity and waste heat from a Phosphoric Acid Fuel Cell (PAFC) system was designed and analyzed in terms of its primary energy saving, CO₂ reduction, fuel cell and CHP efficiency, and economic feasibility. The mathematical model of the thermal load evaluation was used with the 3D multi-zone building model in TRNSYS 18 software (Thermal Energy System Specialists, LLC, Madison, MI, USA) to determine the space heating demand and swimming pool heat losses. The energy efficiency of the fuel cell unit was evaluated as a function of the part-load ratio from the operating data. The fundamental components, such as the auxiliary boiler, thermal storage tank, and heat exchanger are also integrated for the simulation of the system’s operation. The result shows that the system has a high potential to improve the utilization efficiency of fuel cell energy production. Referring to the local condition of the energy market in Korea, an economic analysis was also carried out by using a specific FC-CHP capacity at 440 kW. The economic benefit is significant in comparison with a conventional heating system, especially for the full-time operating (FTO) mode. The net profit made by comparison with the conventional energy supply system is about 178,352 to 273,879 USD per year, and the payback period is expected to be 6.9 to 10.7 years under different market conditions. Full article