Name: LETÍCIA COSTA RIBEIRO
Publication date: 31/03/2017
Advisor:
Name |
Role |
|---|---|
| JOSÉ JOAQUIM CONCEIÇÃO SOARES SANTOS | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| HELDER ROBERTO DE OLIVEIRA ROCHA | External Examiner * |
| JOSÉ JOAQUIM CONCEIÇÃO SOARES SANTOS | Advisor * |
| MARCIO FERREIRA MARTINS | Internal Examiner * |
| WELLINGTON BETENCURTE DA SILVA | Internal Examiner * |
Summary: The Waste Heat Recovery (WHR) uses the heat that is normally discarded by a thermal system, and turns it into a useful form of energy. Among its benefits are: additional CO2-free energy, increased process efficiency and fuel economy. One of the alternatives to recover thermal waste is the application of Organic Rankine Cycles, in order to generate more power without increasing fuel consumption, which will lead to an increase in energy and environmental efficiency. In this work, the modeling and optimization is performed using the Engineering Equation Solver (EES) software to recovery the heat from two thermal rejects, cooling water and exhaust gas, from the internal combustion engines (ICE) of a thermoelectric plant using Organic Rankine Cycles, with two configuration options, with and without regeneration. The optimization performed is thermoeconomic and parametric with the objective of minimizing the cost of the power generated, and selecting which working fluid produces power at a lower cost. For this, thermodynamic and economical modeling are performed, for five decision variables, among them the isentropic efficiency of the pump and turbine. The main contribution of this work is to obtain and adjust cost equations capable of responding to these variables. The results showed that regenerative cycles for both heat sources, despite increasing cycle efficiency, produce a more expensive power than the cycle without regeneration. In the optimum condition, it is possible to obtain an increase of around 7% in the power generated by the thermoelectric plant.
Keywords
Organic Rankine Cycle; Thermoeconomic Optimization; Diesel Engines; Waste Heat Recovery
