I agree, but some users want to evaluate "what if" scenarios and may want to try unconventional control.
For all users:
When specific control is required that is not available with current E+ objects, the EMS should be used to create custom controls. Most of the requests I see for customizing controls can be accomplished with only a few lines of EMS programming.
On 1/27/2012 12:55 PM, YuanLu Li wrote:
Hi, Rochard,
Thank you for the clarification of the controls on the air loop.
T.t is making the control of the plant loop very complicated.
He now wanted to use the availabilityManager:HightemperaturTurnoff to turn the heater off at 80°C tank temperature. and has posted part of an IDF. I did not reply to that one as it is still the same scheme of using two sensors and two controls. .
=================
Using his schematic diagram he provided to the group, all he need to do was to move the second thermometer to the Zone. The radiator would be turned off at 20°C, and the water would go through the by-pass path. The tank heater would turn on and off as the temperature and load changes. The second thermometer at the inlet of the tank to control the heater at 65°C could not be entered in the IDF, was his problem.
If he is really learning on how to use HVAC, he should not ignore the charisteristics of real components.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: RRaustad@xxxxxxxxxxxx
Date: Fri, 27 Jan 2012 11:42:10 -0500
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff
The availability manager actually turns off the pump (or fan for air systems). So any equipment on that loop will be off.
On 1/27/2012 11:25 AM, Tooran T wrote:
From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Friday, January 27, 2012 7:31 PM
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff
thanks Dr.Li ,i m not good at english so mybye i dont undrestand your word exactly .you say : " If the avilability manager is associated with the heater, it turns off the heater." and
" The size and type of the heater is another matter" what you mean by heater ?is that baseboard heater or water heater?thank you very much Dr.Li!- =============
Sizing:Plant,
Boiler Loop, !- Plant or Condenser Loop Name
HEATING, !- Loop Type
80., !- Design Loop Exit Temperature {C}
15; !- Loop Design Temperature Difference {deltaC}
!- ======================is all you need to enter in the IDF. The size and type of the heater is another matter.
=============================
In control engineering most controller has a built in hysteresis. However, you may not be able to specify it exactly, if it is not designed to be adjustable.
What you are trying to do is to design your own controller.
Dr. Li
To: energyplus_support@xxxxxxxxxxxxxxx
From: yli006@xxxxxxxxxxx
Date: Fri, 27 Jan 2012 08:21:27 -0500
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff
If the avilability manager is associated with the heater, it turns off the heater.
If the avilability manager is asspcoated with the tank used side, it turns off the loop supply (pump).
Sensor node need not be in the same loop, but must respond of the change when the control is activated. If the temperature falls below the limit, the control is removed. Back to your thermostat problem. Set-back is not the same as limits.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Fri, 27 Jan 2012 09:36:16 +0000
Subject: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff
Dear memebers ,
ref : Document :EngineeringRefrence.pdf -983
"High temperature turn off :
The input object availabilityManager:High temperaturTurnoff is used to turn off a central air system or a plant loop if a sensed node temperature exceeds a temperature limit."
i want to know availabilityManager:High temperaturTurnoff , turn off the plant loop or just the turn off the component ?
for example : i set field :Sensor Node name : at the outlet of boiler .. in this plant loop there is pump and boiler as a component.
then availabilityManager:High temperaturTurnoff turn off boiler or plant loop ?if it turn off the plant loop it means it turned off pump too?
thanks
-- Richard A. Raustad Senior Research Engineer Florida Solar Energy Center University of Central Florida 1679 Clearlake Road Cocoa, FL 32922-5703 Phone: (321) 638-1454 Fax: (321) 638-1439 or 1010 Visit our web site at: http://www.fsec.ucf.edu UCF - From Promise to Prominence: Celebrating 40 Years
-- Richard A. Raustad Senior Research Engineer Florida Solar Energy Center University of Central Florida 1679 Clearlake Road Cocoa, FL 32922-5703 Phone: (321) 638-1454 Fax: (321) 638-1439 or 1010 Visit our web site at: http://www.fsec.ucf.edu UCF - From Promise to Prominence: Celebrating 40 Years
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