Dynamic Modeling of ORC Power Plants

Abstract

This chapter presents dynamic modeling approaches suitable for organic Rankine cycle (ORC) power plants. Dynamic models are necessary for the better understanding of the plants' behavior during transient operation, such as start-up, shutdown, and during rapid load changes. The estimation of plant operating parameters during transient operation is crucial for monitoring and control of the plant so that the system state variables do not exceed the pre-defined operating range. One example is the proportion of liquid and vapor phase in the condenser and evaporator that must be kept within acceptable ranges to avoid stalling or temperature shocks during transient conditions. Using dynamic models enables plant operators to predict changes in power output as a function of the plant's boundary conditions such as temperature of the heat source and ambient conditions, so that they can respond to the expected heat and power demand accordingly. The aim of the chapter is to investigate and review the methodologies applicable for dynamic simulation of ORC power plants.

Dynamic Modelling of ORC System for Vessel Waste Heat Recovery

“…In general, the dynamic behavior of a system including mechanical, electrical, fluid, thermal etc., can be described by a set of transient differential equations (ODE or PDE). The basic concepts that have to be known in dynamic modelling include system inertia, initial conditions, input stimulus variable and time constant [5].…”