Introduction to the simulation of power plants for EBSILON®Professional Version 15

1 Introduction

EBSILON®Professional is a powerful engineering system developed for the simulation of thermodynamic cycle processes.

It is distributed by STEAG Energy Services GmbH (http://www.steag-systemtechnologies.com). This manual has been created for version 15. When used with other versions (older or newer), there may be differences in the operation or in the standard parameters of the components used.

EBSILON®Professional is suitable as a tool for plant planning, design and optimization of power plants. Combined heat and power plants, combined cycle power plants, combined cycle power plants, combined heat and power plants, etc. can be calculated with the help of the basic program.

In the last years (software versions) the renewable energies have been integrated step by step, so that now also wind energy plants and solar plants can be calculated.

With EBSILON®Professional two main tasks can be handled:

Balancing of the overall process

Design of individual components.

The task of process balancing is to design a functioning overall process and to balance it with regard to the most important process parameters. Essential is the interaction of a large number of components. These have to be designed in detail in such a way that the dimension of a component does not necessarily have to be known from the outset (e.g. blade shape, size of the heat exchanger surface, etc.) Furthermore, the components should be presented as simplified models. It is also necessary to be able to represent full-load and part-load operation.

When designing the individual component, it is important to define the dimensions in more detail. Details, which are important for the design of a component, should be made clear. These are thermodynamic properties and the dimensions of a component. Therefore it is necessary to apply the highest possible level of detail in the modeling (use of FEM or CFD methods).

Power generation plants often deviate from nominal operating conditions and operate within 50% to 100% of nominal load, and their performance parameters change. The EBSILON software has two calculation modes:

Design mode (Design) according to the nominal load and

Partial load mode (Off design) in operation below the nominal load.

The cycle diagrams used in the two calculation modes are identical. The design calculation determines the nominal parameters of the component.

For each component a characteristic power curve can be generated according to the real operating data. This is used to predict the change in power parameters of each component when operating conditions change. These power characteristics are used to calculate the partial load.

2 Functionality of EBSILON®Professional

2.1 General

The modelling software EBSILON®Professional (short: EBSILON) can be used to calculate the most diverse energy-technical systems.

The main task, which is realized by EBSILON, is the process simulation. This is based on two different types of components:

lines

components.

The EBSILON component library contains components for all typical power plant processes. By means of parameters and characteristic curves, the components can be adapted to the real performance behaviour. In addition, there are logical components (e.g. controllers) with which the parameters of the components can be influenced.

In the program environment the whole process is designed and balanced with regard to the most important process parameters. The design of the process is done step by step, first of all a few components are needed to start i.e. with the turbo set. Afterwards, other components can be added, but it must always be checked whether the simulation is running correctly, that means successfully.

Table 1: Selected components

All components have to be connected by lines. The fluid in the lines is determined by mass flow, (temperature,) pressure and enthalpy. The required material data are provided by an integrated extensive material data library.

Calculation algorithms are used in the components to correlate the fluid properties of the outgoing lines with the incoming lines.

Table 2: Selected lines

In addition to the main program, the calculation of a thermal cycle diagram, EBSILON consists of the following modules, some of which are optionally available [STE21]

EbsBoiler – components for detailed mapping of the boiler geometry

EbsSolar – Components for the imaging of a solar field

OEM-GTLib – Gas turbine database based on manufacturer data

EbsOptimize – Integrated optimizer based on genetic algorithm

EbsValidate – Data validation according to VDI 2048

EbsHTML – Plant Model in the web browser

EbsScript – PASCAL-based script language for EBSILON

2.2 Mathematical principles

The mathematical modelling of the thermal cycle diagram is carried out with the aid of a non-linear system of equations, which is solved iteratively. It is built in the background based on the user input. The decisive variables of the equation system are mass flow, pressure and specific enthalpy.

The actual circular process calculation is carried out internally in two partial steps:

Creation of the nonlinear system of equations from the input data of the thermal cycle diagram (geometry of the cycle and thermodynamic key data)

Iterative solving of the system of equations to calculate the remaining unknown parameters and performance variables.

2.3 Explanations of the program interface

The program interface of EBSILON (Figure 1) is structured analogous to other Microsoft Windows programs. Certain commands directly access standard windows, so that the handling of the program is easy to learn.

The usual operating philosophy for Windows applies:

To edit an object on the screen, it must first be clicked on (e.g. assigning values, deleting, moving, etc.).

Several objects can be selected at the same time by simultaneously pressing the Shift key and clicking on them one after the other.

Selected objects can be moved, enlarged, reduced, rotated and mirrored at