Energy and exergy analyses of integrated hydrogen production system using high temperature steam electrolysis

6th International Conference on Progress in Hydrogen Production and Applications (ICH2P) -- MAY 03-06, 2015 -- Oshawa, CANADAWOS: 000376695800033In this study, thermodynamic performance assessment of solar-driven integrated HTSE for hydrogen production is discussed in detail. The system consists of a solar tower, Brayton cycle, Rankine cycle, organic Rankine cycle (ORC) and high temperature steam electrolysis (HTSE). The required heat energy for power generation cycles are supplied from solar energy while produced electricity is used for the necessary energy demand of HTSE. For the analyses, the inlet and outlet energy and exergy rates of all subsystems are calculated and illustrated accordingly. From the results of the analyses, the overall energy and exergy efficiencies of the considered system are found to be 24.79% and 22.36% for power generation section and 87% and 88% for hydrogen production section respectively. Also it is found that without any auxiliary equipment, the considered hydrogen production process consumes 1.98 kWh(e) at 230 degrees C, generates 0.057 kg/s H-2. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved

Thermoeconomic optimization of a LiBr absorption refrigeration system

Optimization of thermal systems is generally based on thermodynamic analysis. Thermoeconomic optimization technique combines thermodynamic analysis with economic constraints to obtain an optimum configuration of a thermal system. In this study, the thermoeconomic optimization technique is applied to a LiBr absorption refrigeration system. Various components of the system such as condenser, evaporator, generator, and absorber heat exchangers are optimized. Additionally, optimum heat exchanger areas with corresponding optimum operating temperatures are determined. A cost function is specified for the optimum conditions. Finally, an example for the optimum design of a 20 kW LiBr system is given

Thermodynamic Analysis and Optimization of Geothermal Power Plants

Thermodynamic Analysis and Optimization of Geothermal Power Plants guides researchers and engineers on the analysis and optimization of geothermal power plants through conventional and innovative methods. Coverage encompasses the fundamentals, thermodynamic analysis, and optimization of geothermal power plants. Advanced thermodynamic analysis tools such as exergy analysis, thermoeconomic analysis, and several thermodynamic optimization methods are covered in depth for different configurations of geothermal power plants through case studies. Interdisciplinary research with relevant economic and environmental dimensions are addressed in many of the studies. Multiobjective optimization studies aimed at better efficiency, lower cost, and a lower environmental impact are also discussed in this book.</p

Different methods for modeling absorption heat transformer powered by solar pond

Solar ponds are a type of solar collector used for storing solar energy at temperature below 90°C. Absorption heat transformers (AHTs) are devices used to increase the temperature of moderately warm fluid to a more useful temperature level. In this study, a theoretical modelling of an absorption heat transformer for the temperature range obtained from an experimental solar pond with dimensions 3.5 × 3.5 × 2 m is presented. The working fluid pair in the absorption heat transformer is aqueous ternary hydroxide fluid consisting of sodium, potassium and caesium hydroxides in the proportions 40:36:24 (NaOH:KOH:CsOH). Different methods such as linear regression (LR), pace regression (PR), sequential minimal optimization (SMO), M5 model tree, M5′ rules, decision table and back propagation neural network (BPNN) are used for modelling the absorption heat transformer. The best results were obtained by the back propagation neural network model. A new formulation based on the BPNN is presented to determine the flow ratio (FR) and the coefficient of performance (COP) of the absorption heat transformer. The BPNN procedure is more accurate and requires significantly less computation time than the other methods