RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

Algorithm is used to design a software for simulation.

In the earlier version of EPlus, I seem to remember, there was a pump by-pass. The newer version does not seem to have that in the examples of the example file.

The work around is to leave the pump in and reduce the pressure to a smaller value to reflect the temperature difference of the up and down pipes which created a pressure difference.

Simulate it without the by-pass and see how much is the pump power. If it is not significant, simply ignore the pump power. You cannot really stop the pump, as the equation used for simulation requires a pressure difference to circulate the water.

Therefore, instead of using a pump, you will have substitute the equation with one that produces the pressure difference due to temperature difference. This is what I meant by changing the algorithm in simulation.

The tank can be controlled to the 80 - 65 range without the pump control.

The zone thermotat if is a common one would turn on and off the pump for all the radiators.
In this case you will not have a thermostat control in each room. If the room have different thermal characteristics, the EPlus simulation will show the differences in room temperature.

Dr. Li

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Fri, 27 Jan 2012 22:09:44 +0000
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

yes exactly we use pump by bypass mode . what do you mean by different algorithm?

From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Friday, January 27, 2012 10:24 PM
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

If you turn on and off the pump at 65°C, to implement the pump by pass mode. Again, it is a different algorithm.

Dr. Li

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Fri, 27 Jan 2012 18:43:08 +0000
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

i want to :

if inlet water pump > 65C then pump will be off

and if inlet water pump < 65 then pump will be on

for this type of controling can we use two availabilityManager:

one availabilityManager:High temperaturTurnoff :for inlet water pump > 65C then pump will be off .

and another availabilityManager: low temperaturTurnon : for inlet water pump < 65 then pump will be on.

is that right?

thanks

From: Richard Raustad <RRaustad@xxxxxxxxxxxx>
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Sent: Friday, January 27, 2012 8:12 PM
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
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Fax:     (321) 638-1439 or 1010
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