Full Load Boiler

Modelling
,
1

Hi everyone,

we are currently looking for a framework for modelling cascaded boilers for a project idea. These boilers have the property that they can only work under full load in addition to the start-up and shut-down process.
Is it possible to model such a property in solph? Start up ramp → full load → shut down ramp

Thank you!
Best regards
Lukas

2

Hi @Luk,

Modelling only off or full load is really straightforward in solph. Additionally, we implemented a variable that signifies the time steps when startup or shutdown happens. When you create a second Converter for the ramps, you can constraint it in a way that it models the ramps.

Note that this kind of optimisation with predefined ramps will result in a combinatoric problem rather than a pure linear optimisation. Thus, the computational time will increase. (This is true regardless of the framework you use.) If you proceed with the idea, please share your experience, regardless of which framework you decide for.

Cheers,
Patrik

1 Like
3

I am quite new to oemof and I am having the same problem in a different context. Would you mind giving a simple example of making a CHP plant (modelled as a simple solph.components.Converter) into an “on” or “off” type of device?

4

It would be like this:

bus_gas = Bus("gas bus")
bus_electricity = Bus("electricity bus")
energy_system.add(bus1, bus2)

energy_system.add(
    Converter(
        label="ON/OFF CHP",
        inputs={bus_gas: Flow(nominal_value=),
        outputs={bus_electricity: Flow(
            nominal_value=2,
            min=1,
            nonconvex=NonConvex()
        )},
        conversion_factors={bus_electricity: 0.35},
    )
)

Again: Note that this will be a lot slower compared to an optimisation without NonConvex (i.e. that allows part loads with the same efficiency).

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