Conceptual design and performance analysis of a novelCHPsystem integrated with solid oxide fuel cell and supercriticalCO₂partial preheating cycle

Abstract

Summary The paper proposes a novel combined heating and power (CHP) system integrated with solid oxide fuel cell (SOFC) and supercritical CO2 (SCO2) partial preheating cycle to improve the energy utilization rate by employing the SCO2 cycle to recover the waste heat from the SOFC. The SCO2 partial preheating cycle can not only improve the net output power but also preheat the air supplied to the SOFC for enhancing the system efficiency. Sensitivity analysis is implemented to study the influences of six key parameters (ie, fuel flow rate, excess air ratio, fuel utilization factor, CO2 turbine inlet temperature, CO2 compressor pressure ratio, and CO2 split ratio) on the proposed system in terms of thermodynamic behaviors. And then the optimal operating conditions for the different objectives are determined by parametric optimization. The results indicate that the optimal overall electrical efficiency and CHP efficiency of the proposed system are 72.84% and 83.83% respectively, while the exergy efficiency can achieve 70.84%. Furthermore, the best trade‐off result is obtained with the energy output of 434.71 kW and the exergy efficiency of 64.28%. Finally, the investigation demonstrates the fuel flow rate is the most sensitive parameter which should be determined with the comprehensive consideration of the efficiency and energy output, and the lower excess air ratio and higher CO2 turbine inlet temperature are preferred for power generation.

Development of a novel dual heated cascade supercritical carbon dioxide cycle and performance comparison with existing two configurations for waste heat recovery

“…Due to the fact that CO 2 has a low critical temperature, a lower compression work can be obtained near the critical point, thus obtaining a higher efficiency. 8,9 So far, S-CO 2 cycle has been extended to solar energy, 10,11 fossil fuel, 12 fuel cell, 13 and geothermal energy. 14 In recent years, relevant researches have been intensively conducted, and various efficient cycle configurations including recuperated cycle, recompression cycle, and pre-compression cycle, have been constructed according to the characteristics of heat sources.…”

Thermoeconomic analysis and multi‐objective optimization of a solid‐oxide fuel cell plant coupled with methane tri‐reforming: Effects of thermochemical recuperation

“…Huerta et al 13 evaluated the performance of a diesel pre‐reforming SOFC‐system with AOGR form an exergy perspective and concluded that optimum recirculation and low oxygen/carbon ratios led to relatively high system exergy efficiencies. Zhong et al 14 evaluated the performance of a novel SOFC‐based combined heat and power (CHP) system integrated with CO 2 partial preheating cycle. Applying an ejector to overcome the pressure drop, some part of the anode off‐gas was recycled and redirected to an external pre‐reformer.…”