Add More Cookers for Parallel Operation

Add More Cookers for Parallel Operation#

This sections explains how to model the parallel operation of two process steps using the previous cooker example which is shown in Fig. 3. In this example two cookers are implemented.

../_images/parallel_cooker_operation.png — Fig. 3 Depiction of the cooker model with two parallel cookers.#

Therefore two process chains must be created. Each of the chains must hold an own instance of the cooker.

Create Two Process Chains#

The first change that must be applied is to the original example is to add an additional process chain.

process_chain_1 = network_level.create_process_chain(
    process_chain_name="Cooker Chain 1"
)
process_chain_2 = network_level.create_process_chain(
    process_chain_name="Cooker Chain 2"
)

Connect Chains with Sink and Source#

Both chains must then be connected to the sink and source

process_chain_1.add_sink(sink=sink)
process_chain_1.add_source(source=source)
process_chain_2.add_sink(sink=sink)
process_chain_2.add_source(source=source)

Create two process steps#

Then two process steps are created.

process_step_1 = process_chain_1.create_process_step(name="Cooker 1")
process_step_2 = process_chain_2.create_process_step(name="Cooker 2")

Create Streams#

Afterwards an own input and output stream must be created for each of the process steps.

raw_materials_to_cooking_stream_1 = process_chain_1.stream_handler.create_batch_stream(
    batch_stream_static_data=BatchStreamStaticData(
        start_process_step_name=source.name,
        end_process_step_name=process_step_1.name,
        delay=datetime.timedelta(minutes=1),
        commodity=input_commodity,
        maximum_batch_mass_value=0.0005,
    )
)
cooking_to_sink_stream_1 = process_chain_1.stream_handler.create_batch_stream(
    batch_stream_static_data=BatchStreamStaticData(
        start_process_step_name=process_step_1.name,
        end_process_step_name=sink.name,
        delay=datetime.timedelta(minutes=1),
        commodity=output_commodity,
        maximum_batch_mass_value=0.0005,
    )
)

raw_materials_to_cooking_stream_2 = process_chain_2.stream_handler.create_batch_stream(
    batch_stream_static_data=BatchStreamStaticData(
        start_process_step_name=source.name,
        end_process_step_name=process_step_2.name,
        delay=datetime.timedelta(minutes=1),
        commodity=input_commodity,
        maximum_batch_mass_value=0.0005,
    )
)
cooking_to_sink_stream_2 = process_chain_2.stream_handler.create_batch_stream(
    batch_stream_static_data=BatchStreamStaticData(
        start_process_step_name=process_step_2.name,
        end_process_step_name=sink.name,
        delay=datetime.timedelta(minutes=1),
        commodity=output_commodity,
        maximum_batch_mass_value=0.0005,
    )
)

Connect Streams#

Then both of the streams must be connected to respective sink and source. It is not necessary to add them to the respective process step.

source.add_output_stream(
    output_stream=raw_materials_to_cooking_stream_1,
    process_chain_identifier=process_chain_1.process_chain_identifier,
)
sink.add_input_stream(
    input_stream=cooking_to_sink_stream_1,
    process_chain_identifier=process_chain_1.process_chain_identifier,
)
source.add_output_stream(
    output_stream=raw_materials_to_cooking_stream_2,
    process_chain_identifier=process_chain_2.process_chain_identifier,
)
sink.add_input_stream(
    input_stream=cooking_to_sink_stream_2,
    process_chain_identifier=process_chain_2.process_chain_identifier,
)

Create Petri Nets#

Afterwards the petri net must be created for each of the process steps. For the sake of brevity the simpler petri net from the initial example is used:

Cooker 1:#

idle_state_1 = process_step_1.process_state_handler.create_idle_process_state(
    process_state_name="Idle"
)
fill_raw_materials_state_1 = (
    process_step_1.process_state_handler.create_batch_input_stream_requesting_state(
        process_state_name="Fill raw materials"
    )
)

cooking_state_1 = process_step_1.process_state_handler.create_intermediate_process_state_energy_based_on_stream_mass(
    process_state_name="Cooking"
)

discharge_goods_state_1 = (
    process_step_1.process_state_handler.create_batch_output_stream_providing_state(
        process_state_name="Discharge"
    )
)

activate_not_cooking_1 = process_step_1.process_state_handler.process_state_switch_selector_handler.process_state_switch_handler.create_process_state_switch_at_next_discrete_event(
    start_process_state=discharge_goods_state_1,
    end_process_state=idle_state_1,
)
process_step_1.process_state_handler.process_state_switch_selector_handler.create_single_choice_selector(
    process_state_switch=activate_not_cooking_1
)

activate_filling_1 = process_step_1.process_state_handler.process_state_switch_selector_handler.process_state_switch_handler.create_process_state_switch_at_input_stream(
    start_process_state=idle_state_1,
    end_process_state=fill_raw_materials_state_1,
)

process_step_1.process_state_handler.process_state_switch_selector_handler.create_single_choice_selector(
    process_state_switch=activate_filling_1
)

activate_cooking_1 = process_step_1.process_state_handler.process_state_switch_selector_handler.process_state_switch_handler.create_process_state_switch_delay(
    start_process_state=fill_raw_materials_state_1,
    end_process_state=cooking_state_1,
    delay=datetime.timedelta(minutes=30),
)

process_step_1.process_state_handler.process_state_switch_selector_handler.create_single_choice_selector(
    process_state_switch=activate_cooking_1
)


activate_discharging_1 = process_step_1.process_state_handler.process_state_switch_selector_handler.process_state_switch_handler.create_process_state_switch_at_output_stream(
    start_process_state=cooking_state_1,
    end_process_state=discharge_goods_state_1,
)
process_step_1.process_state_handler.process_state_switch_selector_handler.create_single_choice_selector(
    process_state_switch=activate_discharging_1
)

Cooker 2#

# Process Step 2

idle_state_2 = process_step_2.process_state_handler.create_idle_process_state(
    process_state_name="Idle"
)
fill_raw_materials_state_2 = (
    process_step_2.process_state_handler.create_batch_input_stream_requesting_state(
        process_state_name="Fill raw materials"
    )
)

cooking_state_2 = process_step_2.process_state_handler.create_intermediate_process_state_energy_based_on_stream_mass(
    process_state_name="Cooking"
)

discharge_goods_state_2 = (
    process_step_2.process_state_handler.create_batch_output_stream_providing_state(
        process_state_name="Discharge"
    )
)

activate_not_cooking_2 = process_step_2.process_state_handler.process_state_switch_selector_handler.process_state_switch_handler.create_process_state_switch_at_next_discrete_event(
    start_process_state=discharge_goods_state_2,
    end_process_state=idle_state_2,
)
process_step_2.process_state_handler.process_state_switch_selector_handler.create_single_choice_selector(
    process_state_switch=activate_not_cooking_2
)

activate_filling_2 = process_step_2.process_state_handler.process_state_switch_selector_handler.process_state_switch_handler.create_process_state_switch_at_input_stream(
    start_process_state=idle_state_2,
    end_process_state=fill_raw_materials_state_2,
)

process_step_2.process_state_handler.process_state_switch_selector_handler.create_single_choice_selector(
    process_state_switch=activate_filling_2
)

activate_cooking_2 = process_step_2.process_state_handler.process_state_switch_selector_handler.process_state_switch_handler.create_process_state_switch_delay(
    start_process_state=fill_raw_materials_state_2,
    end_process_state=cooking_state_2,
    delay=datetime.timedelta(minutes=30),
)

process_step_2.process_state_handler.process_state_switch_selector_handler.create_single_choice_selector(
    process_state_switch=activate_cooking_2
)


activate_discharging_2 = process_step_2.process_state_handler.process_state_switch_selector_handler.process_state_switch_handler.create_process_state_switch_at_output_stream(
    start_process_state=cooking_state_2,
    end_process_state=discharge_goods_state_2,
)
process_step_2.process_state_handler.process_state_switch_selector_handler.create_single_choice_selector(
    process_state_switch=activate_discharging_2
)

Add Energy Data#

Now the energy data must be added two the states of each machine.

electricity_load = LoadType(name="Electricity")
cooking_state_1.create_process_state_energy_data_based_on_stream_mass(
    specific_energy_demand=1.8,
    load_type=electricity_load,
    stream=raw_materials_to_cooking_stream_1,
)
cooking_state_2.create_process_state_energy_data_based_on_stream_mass(
    specific_energy_demand=1.8,
    load_type=electricity_load,
    stream=raw_materials_to_cooking_stream_2,
)

Create Mass Balances and Storages#

The last step is to add an own mass balance and storage to each of the process steps.

process_step_1.create_main_mass_balance(
    commodity=output_commodity,
    input_to_output_conversion_factor=1,
    main_input_stream=raw_materials_to_cooking_stream_1,
    main_output_stream=cooking_to_sink_stream_1,
)

process_step_1.process_state_handler.process_step_data.main_mass_balance.create_storage(
    current_storage_level=0
)


process_step_2.create_main_mass_balance(
    commodity=output_commodity,
    input_to_output_conversion_factor=1,
    main_input_stream=raw_materials_to_cooking_stream_2,
    main_output_stream=cooking_to_sink_stream_2,
)


process_step_2.process_state_handler.process_step_data.main_mass_balance.create_storage(
    current_storage_level=0
)

The process to start the simulation is the same as in the previous example. It does not depend on the configuration of process steps, process chains and network level. The next example shows how to connect two process steps exclusively using a process chain.