[EnergyPlus_Support] Why the generators stop working when selected "Follow Thermal"

["pzhaocsm" <pzhaocsm@xxxxxxxxx>]

Hello, 
I have tried the HeatRecoveryPlantLoop.idf for CHP application.
I selected "follow thermal" of "Generator Operation Scheme Type" in "ElectricLoadCenter:Distribution" object. When the "follow thermal" option is selected, the three generators all stopped working and of course no thermal energy output. But I found the output of "HOT WATER LOOP:Plant Loop Unmet Demand" was zero, so the thermal demand must be met by the water heater on the heating loop.
Then I checked the "Big Water Heater" of "WaterHeater:Mixed", which is on the heat recovery loop (and also on the supply side of heating loop) and supposed to collect the hot water from generators for heating coils. I found the "Big Water Heater" is running on electricity with maximum "200000 W", I turned it to be "0", because I want the heating demand met by recovered hot water from generators. 
But the simulation result is: The generators are still not working (no electricity output, not thermal output), the output of "HOT WATER LOOP:Plant Loop Unmet Demand" to be very high, so all of the heating demand was not met, and room temperature goes down to be -1 or -2 in the winter. So the thermal output (now is zero) of generators are not following the demand.
How does this happen? How can I make the generators working on following the thermal load? How can I use the recovered hot water for heating instead of electric water heaters?

Thanks a lot!
Peng



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

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.
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/EnergyPlus_Support/

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/EnergyPlus_Support/join
    (Yahoo! ID required)

<*> To change settings via email:
    EnergyPlus_Support-digest@xxxxxxxxxxxxxxx 
    EnergyPlus_Support-fullfeatured@xxxxxxxxxxxxxxx

<*> To unsubscribe from this group, send an email to:
    EnergyPlus_Support-unsubscribe@xxxxxxxxxxxxxxx

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/