How temperature setpoint and sensed temperature is calculated in "Controller:WaterCoil"

asked 2017-10-15 21:14:32 -0500

2085 ●1 ●4 ●14

I am modelling for LEED baseline system 8.
When I tried to implement Chilled-Water Design Supply Temperature Reset in HVACTemplate:Plant:ChilledWaterPlant, I got following error.

 ** Severe  ** FindRootSimpleController: Controller error for controller = "A_LZ_SYS COOLING COIL CONTROLLER"
   **   ~~~   **  Environment=ANNUAL, at Simulation time=01/04 05:40 - 05:50
   **   ~~~   **   Controller function is inconsistent with user specified controller action = Reverse action
   **   ~~~   **   Actuator will be set to maximum action
   **   ~~~   ** Controller control type=Temperature and humidity ratio
   **   ~~~   ** Controller temperature setpoint = 9.64 [C]
   **   ~~~   ** Controller sensed temperature = 12.02 [C]
   **   ~~~   ** Controller humidity ratio setpoint = 1.09E-002 [kg-H2O/kg-air]
   **   ~~~   ** Controller sensed humidity ratio = 6.46E-003 [kg-H2O/kg-air]
   **   ~~~   ** Controller actuator mass flow rate set to 165.08 [kg/s]

Referring to other post , I tried to debug it. However, I don't know how Controller temperature setpoint and Controller sensed temperature are calculated which makes debug difficult.
Can anyone tell me any document or pages which is explaining how these two are different and calculated?

answered 2017-10-16 14:26:54 -0500

rraustad

13599 ●72 ●12 http://www.fsec.ucf.edu/

updated 2017-10-16 14:28:14 -0500

In the water coil controller there is a field named Sensor Node Name. This is the location where the temperature is sensed. In EnergyPlus, this variable name is Node().Temp. Also at this same node is the set point temperature found in the variable Node().TempSetPoint.

Controller:WaterCoil,
  Main Cooling Coil Controller,  !- Name
  Temperature,             !- Control Variable
  Reverse,                 !- Action
  FLOW,                    !- Actuator Variable
  Air Loop Outlet Node,    !- Sensor Node Name
  Cooling Coil Water Inlet Node,  !- Actuator Node Name

The names of each node is stored in the array NodeID. The data for each node, for example the node temperature, mass flow rate, humrat, etc., are stored in each node array.

If this figure, the names of each node are shown in the top figure for the NodeID array. The lower figure shows node 2 where each parameter for Node(2) is shown including Temp and TempSetPoint.

image description

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Comments

@rraustad would you please let me know how to pull out that NodeID (where that file is stored)? Thanks!

Mohammad ( 2021-11-11 11:28:21 -0500 )edit

Sorry, I didn't see this comment. Output:Variable,NameOfTheNode,System Node Temperature, hourly;

rraustad ( 2022-02-02 18:41:49 -0500 )edit

Oh, did you mean how do you see the NodeID in an interface developers tool? You would add NodeID to the watch window, and would also need the class name, so DataLoopNode::NodeID. If you are using the latest version of E+ it would be state.dataLoopNodes->NodeID

rraustad ( 2022-02-02 18:47:03 -0500 )edit

Thank you so much @rraustad

Mohammad ( 2022-02-07 00:03:01 -0500 )edit

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