Thermodynamic analysis and examining the effects of parameters in BSR-HDH system using response surface methodology

Abstract

1) Background: In this study, biogas steam reforming (BSR) coupled with a humidification dehumidification unit (HDH) was proposed and the novel thermodynamic analysis interaction effects on energy efficiency and exergy efficiency via the design of experiments was used. 2) Methods: Comprehensive thermodynamic modelling has been performed using EES software. Thus, by utilizing the thermodynamic analysis of the combined system by EES software and transferring the experiments based on the central composite design for the input parameters (the inlet temperature of the dehumidifier, humidifier and dehumidifier circulated mass flow rate and the desalination heater inlet temperature) extracted by the design expert software, the results obtained from the EES provides responses that shows the impact of the interaction of the input parameters. In RSM model, the central composite design (CCD) is employed in the experimental design. 3) Significant Findings: From the thermodynamic outlet results, the energy efficiency, exergy efficiency, hydrogen mass flow rate and freshwater mass flow rate of the system are obtained 82.39% and 72.65%, 0.1071 kg/s and 0.211 kg/s, respectively. R2 values in energy and exergy efficiency responses were calculated 99.99% and 99.97%, respectively that shows the model has a good accuracy. The optimum points for parameters of the inlet temperature of dehumidifier (T14), humidifier and dehumidifier circulated mass flow rate (m19) and the desalination heater inlet temperature (T10) and also responses of energy efficiency and exergy efficiency are obtained 310 K, 8 kg/s, 450 K, 0.9051% and 0.7313%, respectively. Also, the variables of the inlet temperature of dehumidifier and humidifier and dehumidifier circulated mass flow rate (m19) have more interaction with each other based on their slope changes in the upper and lower ranges.