Advanced control logic for Generation III templates
All Generation III templates are supported by advanced automated control logic. These robust control strategies require only limited user input before simulations can be performed. The control logic may look complex at first, but the same patterns are used across many templates. Users are therefore encouraged to review the control logic description carefully when working with automated control templates for the first time.
End units
When the end units are not the core aspect of the templates, a generic end unit block is used. These are single-unit blocks that represent an unspecified equivalent pool of end users. During simulation, a representative heat demand is automatically imposed on the block without any required action from the user.
The imposed heat load is determined by three parameters:
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Design capacity: the design capacity entered in the end-unit block. This value should be adjusted when the template is inserted into the model. It is extracted from the block by the Design values extractor base circuit.
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Relative heat demand: a demand curve between 0 and 1 as a function of outside temperature. A value of 1 means that 100% of the design capacity is required. A value of 0 means that no heat load is required.
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Activation signal: a time-based signal that activates the heat demand. By default, the heat demand is always active.
When calibrating a demand profile, adjust the relative heat demand and the activation signal. The design capacity is a static parameter and should not be changed during calibration, because it represents the installed heating capacity.
Hybrid blocks
A detailed control philosophy for each type of hybrid block can be found here: Control philosophy for hybrid units with advanced control logic.
When a hybrid block, such as a series, parallel, or shunt configuration, is the main focus of a template, the control logic is usually built around a dedicated programmable controller with specific input parameters.
Hybrid blocks always contain a prioritised gate and a secondary gate. The hybrid control logic determines whether the secondary gate must be activated or deactivated to supply the required heat load. Each hybrid block type has its own programmable controller with dedicated inputs and outputs, but the controller structure is similar across the different configurations.
Production blocks
Automated production controllers determine which production units in a cascade must be activated and how much power each unit must produce to reach the temperature setpoint. Each production block type has a dedicated programmable controller with its own inputs and outputs, but the core structure is similar across the different production technologies.
Gas boilers & E-boilers
Boilers are thermal production units that operate in heating mode only. The advanced control logic determines when an activation signal and a modulation signal must be sent to each production unit. A detailed description of its control philosophy can be found here: Control philosophy for gas boilers & E-boilers.
Heat pumps for one mode only
Heat pumps that operate in one mode only use a control strategy that is similar to boiler control. An activation signal and a modulation signal must be sent to each production unit. A detailed description of its control philosophy can be found here: Control philosophy for heat pumps & chillers operating in one mode only.
Reversible heat pumps
Reversible air source heat pumps can operate in both heating and cooling mode. Their control strategy is similar to the strategy used for one-mode heat pumps, but includes additional logic to determine the active operating mode. When the heat pump operates in heating mode, the cooling side must be deactivated, and vice versa. If both heating and cooling demand are present at the same time, the controller uses the selected priority mode to determine which demand is served. A detailed description of its control philosophy can be found here: Control philosophy for reversible heat pumps.
Simultaneous heat pumps
Water source heat pumps operate simultaneously in heating and cooling mode. Their control strategy similar is similar to reversible heat pumps, but includes additional logic for heat dump availability. Because these heat pumps normally require both heating and cooling demand to operate, the controller determines the prioritised operating mode and whether unused heating or cooling can be rejected through cooling towers, dry coolers, or other dump units. A detailed description of its control philosophy can be found here: Control philosophy for simultaneous heat pumps.
Polyvalent heat pumps
Polyvalent heat pumps combine the features of a reversible heat pump and a simultaneous heat pump to operate simultaneously in heating and cooling mode, only in heating or cooling mode, or partially simulaneously with top-up in one mode. Their control strategy is therefore a combination of the simultaneous and reversible heat pump. Due to the flexibility of the polyvalent heat pump, no prioritisation mode has to be defined, and the controller can simply determine which activation signals and modulation signals must be sent to each production unit. A detailed description of its control philosophy can be found here: Control philosophy for polyvalent heat pumps.