BiogasPlant

Use

The biogas plant is modeled as a power plant in combination with a biogas storage facility. Please note that the model is only used to generate electricity. The waste heat generated by the power plant is recooled via a cooling tower or similar system.

Parameters and Connectors

The model requires the connections ▶EnvironmentConditions to read out a text file, the specification of the reference electricity production (▶PRef) and the connection to a power grid (default ▶MVGrid) to feed in the electricity produced.

Inside, the model consists of a combined heat and power unit, a recooler, a power controller, a pump and a grid. The integrated power plant has been modeled using a co-generation system in which the output waste heat is not used for heating purposes but rather dissipated via a dry cooler model.

The ConstantOutput, RelModMon and nUnits settings can be set in the same way as for the CHP. This also applies to the entire CHP properties tab. The proportion of thermal energy is therefore the amount of energy that must be dissipated via the recooler. The GridType and VGrid parameters are taken from the grid model.

The parameters on the Recooling tab can be set in the same way as for the dry cooling tower. The only difference is that the maximum recooling power (MaximumWasteHeat) must also be defined. This is used for dimensioning the dry cooler.

The biogas tank is virtually fed by a biogas production curve, which is defined via a text file. This file is specified by the FileName and TableName parameters. It is expected that the production is specified in Watt. This production is then filled into a virtual storage, which size can be defined via CBiogasStorage. An initial SOC (SOCInit) can also be specified. If a minimum fill level (SOC <=SOCShutdown) is reached in the biogas storage, the power plant is switched off. This may be the case if the fuel consumption of the power plant is higher than the biogas production (defined by the production curve). If the CHP can modulate (ConstantOutput = 'false'), this happens when the SOC of the storage tank is within the limits SOCMinModulation and SOCMaxModulation.

The model has an internal power controller that is automatically parameterized to the needs of the power plant. The SwitchOnPower parameter serves as the switch-on limit. If the requested electrical power ▶PRef exceeds or falls below this limit (taking the hysteresis PDiffCtrl into consideration), the controller turns the plant on or off, respectively.

Model Background

The internal structure of the model is shown in the following illustration.