Re: [EnergyPlus_Support] The control problem

[Philip Haves <phaves@xxxxxxx>]

Dear Ying Yan,

Check that you actually have water through the coil and through the boiler, using report variables for the actual flow. Then check that the boiler is enabled - it may be scheduled off.

Hope this helps,

Phil

On 12/18/2013 12:06 PM, Yan, Ying wrote:

 

Dear all,

I encountered a strange thing.  I used a boiler to provide the hot water to the heating coil in the winter to ensure that the output air temperature should be 14 C.  The setpoint of the boiler is that the output water should be 80 C.  However, when I do the simulation, I got an error report as:

-------------------------------------------------------------------------------------------------------------

** Severe  ** FindRootSimpleController: Controller error for controller = "FAU_1FLOOR AHU HEATING COIL CONTROLLER"

   **   ~~~   **  Environment=ENNSMARTBUILDING, at Simulation time=12/15 00:00 - 00:30

   **   ~~~   **   Controller function is inconsistent with user specified controller action = "" action

   **   ~~~   **   Actuator will be set to maximum action

   **   ~~~   ** Controller control type=Temperature

   **   ~~~   ** Controller temperature setpoint = 14.00 [C]

   **   ~~~   ** Controller sensed temperature = 13.38 [C]

   **   ~~~   ** Controller actuator mass flow rate set to 1.39 [kg/s]

   **   ~~~   ** Controller actuator temperature = 11.71 [C]

   **   ~~~   **   Note: Chilled water coils should be reverse action and the entering chilled

   **   ~~~   **         water temperature (controller actuator temperature) should be below the setpoint temperature

   **   ~~~   **   Note: Hot water coils should be normal action and the entering hot

   **   ~~~   **         water temperature (controller actuator temperature) should be above the setpoint temperature 

-------------------------------------------------------------------------------------------------------------

You can see that the setpoint is 14 C, and the hot water temperature is just 11.71 C. Therefore, the air temperature cannot increase because the water temperature is lower than the air temperature.  But it is strange because the water temperature should be 80 C since it comes from the boiler, rather than 11.71 C.  I do not know why this thing happened.  Can you give me some suggestions?  Thank you.

----------------------------------------

Best Regards

Ying Yan

Graduate Student

Electrical & Computer Engineering

School of Engineering

University of Connecticut

-- 
Philip Haves
Leader, Simulation Research Group 
Lawrence Berkeley National Laboratory
One Cyclotron Road, MS 90R3145
Berkeley, CA 94720-8134
(510) 486 6512 (office)
(510) 486 4089 (fax)

__._,_.___

Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx

The primary EnergyPlus web site is found at:
http://www.energyplus.gov

The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/

Attachments are currently allowed but be mindful that not everyone has a high speed connection.  Limit attachments to small files.

EnergyPlus Documentation is searchable.  Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.

Your email settings: Individual Email|Traditional
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe

__,_._,___