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Similar to the other controllers, there are 2 sections: The Energy centre and the controller itself, with an oversimplified secondary side (which, if you have modeled your own, can be deleted).
HP - Cascade of 2
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HPs - Parallel storage tank - HP modulation
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Settings to change to use this controller
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TempBufferHighSetpoint
Standard value: 40 (in °C)
The setpoint used to (de)activate the heat pumps. This value is best changed combined with the earlier setpoint. (if If this value is set lower, the heat pump will deactivate before the vessel has been filled.).
TempBufferHighHysteresis
Standard value: 3 (in °C)
The Hysteresis hysteresis value sets a hysteresis temperature of the storage tank
TempBufferHighMin = TempBufferHighSetpoint - TempBufferHighHysteresis;
Standard value: calculated based on previous 2 parameters (in °C)
Minimal temperature of the storage tank
TempOutsideMin;
Standard value: -10 (in °C)
If the minimal outside temperature, if the measured outside temperature goes below this minimal temperature, the controller will be deactivated in order to protect the heat pump.
MinModulationHP;
Standard value: 50 (in %)
The minimum modulation that the heat pumps are activated to
MinModulationHPhysteresis;
Standard value: 5 (in %)
Hysteresis value of the minimal modulation value
TimedelayHPs
Standard value: 4 (in minutes)
Start up delay of the heat pump
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HP1 in enabled on 3 conditions:
The top of the thermal store is below TempBufferHighSetpoint.
Temperature outside is higher is than TempOutsideMin.
Timer HP1 is higher than or equal to the time delay of 4 minutes.
HP1 get disabled when:
Temperature outside is lower than TempOutsideMin.
The top of the thermal store is higher than TempBufferHighSetpoint.
HP2 is enabled when:
Heat pump 1 is working.
The top of the thermal store is below 37°C.
Timer HP2 is higher than or equal to the time delay of 4 minutes
HP2 is disabled when:
Heat pump 1 isn’t working.
The top of the thermal store is higher than 40°C.
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The system can be further optimised by doing sensitivity studies. For instance, a sensitivity study can be done for the size of the storage vessel.
The user can change the design temperatures, thermal power, end units, etc. Keep in mind that the controls have to be changed as well. This can be done by changing the “settings” in the programmable controller which are listed in the top of the code. After changing the settings, the correct operation has to be checked again. The user should only change the “settings” and nothing else in the code to make sure the correct control strategy is still valid.
If the user changes the power of the end - units the thermal capacity of the condenser doesn’t change automatically. The user should implement a correct capacity corresponded corresponding with the thermal power of the heat pump.
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Change the external temperature by a sine wave to the evaporation temperature of the heat pump
HP - Cascade of 2
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HPs - Parallel storage tank - HP shift for equal running hours
Similar to the previous template, except for a shifting option between HP’s HPs when the first HP starts. If heat pump 1 has more running hours, heat pump 2 will start the sequence first.
HP - Cascade of 2
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HPs - Parallel storage tank - HP with 2 stages
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This template is a combination of template “HP - Cascade of 2 HP’s - Parallel storage tank - HP modulation” and template with HP’s in stages found in Heat Pump stages.
HP - Cascade of 2
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HPs - Serial storage tank - HP modulation
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Similar to the template “HP - Cascade of 2 HP’s - Parallel storage tank - HP modulation” except with a thermal store on the return instead of the parallel thermal store. An important difference is that the flow temperature is now used to regulate the heat pumps instead of the parallel storage vessel temperature.
HP - Cascade of 2
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HPs - Serial storage tank and low loss header - HP modulation
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Similar to the previous template, except with a low loss header to ensure a constant flow through the heat pumps.
HP - Cascade of 3
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HPs - Parallel storage tank - HP modulation
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Similar to the template “HP - Cascade of 2 HP’s - Parallel storage tank - HP modulation” except with 3 heat pumps instead of 2.