Steady-state and dynamic modelling of a 1 MWel commercial waste heat recovery ORC power plant

ORC power systems have been proven to be a mature technology for low quality waste heat recovery applications. ORC units stand out for their simple structure, reliability and costeffectiveness. The non-constant nature of the energy source requires the ORC power unit to be flexible. Dynamic modelling can be adopted to evaluate and optimize the response time of a system in case of transient conditions, to develop and test control strategies, to support the tuning of the controller and to support maintenance. In this work the dynamic model of a 1 MWel commercial ORC unit is presented. The dynamic model is developed based on the ThermoCycle Modelica library. The different component model are validated in steady-state against 21 measurements points. The dynamic model of the whole power unit is then developed connecting the validated component models. Different modelling approaches of various complexity are implemented to model the heat exchangers of the power system. The performance of the developed heat exchanger (HX) models are tested by running different transient simulations. The results allow identifying benefits and limitations of the tested HX modelling approaches.

[1]  L. Nilsson,et al.  Waste Heat Recovery by Organic Rankine Cycle (ORC) for Moist Exhaust Gases From Paper Industry , 2017 .

[2]  Bertrand Dechesne,et al.  Comparison of moving boundary and finite-volume heat exchangers models in the Modelica language , 2016 .

[3]  Vincent Lemort,et al.  Experimental comparison of organic fluids for low temperature ORC (organic Rankine cycle) systems for waste heat recovery applications , 2016 .

[4]  Danièle Revel,et al.  World Energy Outlook Special Report 2015: Energy and Climate Change , 2015 .

[5]  Sylvain Quoilin,et al.  Dynamic modeling of thermal systems using a semi-empirical approach and the ThermoCycle Modelica Library , 2015 .

[6]  Vincent Lemort,et al.  ThermoCycle: A Modelica library for the simulation of thermodynamic systems , 2014 .

[7]  Vincent Lemort,et al.  Pure and Pseudo-pure Fluid Thermophysical Property Evaluation and the Open-Source Thermophysical Property Library CoolProp , 2014, Industrial & engineering chemistry research.

[8]  Francesco Casella,et al.  Dynamic Modeling of Organic Rankine Cycle Power Systems , 2013 .

[9]  Tobias S. Schmidt,et al.  Shedding light on solar technologies—A techno-economic assessment and its policy implications , 2011 .

[10]  James E. Braun,et al.  A comparison of moving-boundary and finite-volume formulations for transients in centrifugal chillers , 2008 .

[11]  Christoph Richter,et al.  Proposal of New Object-Oriented Equation-Based Model Libraries for Thermodynamic Systems , 2008 .

[12]  A. Abdel-azim.  Fundamentals of Heat and Mass Transfer , 2011 .

[13]  Francesco Casella,et al.  ExternalMedia: a Library for Easy Re-Use of External Fluid Property Code in Modelica , 2008 .

[14]  H. Elmqvist,et al.  MODELICA — THE NEXT GENERATION MODELING LANGUAGE AN INTERNATIONAL DESIGN EFFORT Hilding Elmqvist , 1997 .

[15]  A. Prasad,et al.  Power Generation From Waste Heat Using Organic Rankine Cycle Systems , 1980 .