Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

Dear Dr.Li

i read this :

A hot water heater is the storage tank of water that is responsible for the supply of hot water to the many fixtures in the house, such as showers and sinks. It does NOT supply heat for the home itself. There are two basic types of water heaters, one that runs on gas or some other fuel and one that runs on electric. A boiler on the other hand IS responsible for the heating of a home itself. Water or steam in a boiler reach much higher temperatures than the water in a hot water tank and therefore its used for heating and not drinking water or potable water. In a steam system for heating, pipes run throughout the house from the boiler carrying steam that eventually gives off its heat at the many radiators. In a hydronic system for heat, smaller pipes carry hot water to various baseboards around the house that release the heat using circulator pumps to push the water through and back to the boiler.

the building that i modeled : the boiler has thermometer and the heater that includ portable water doesn have thermometr it is heat exchanger that has two coil one for hot water from boiler and another for shower ,sink,...

could you please help me

thanks

From: Tooran T <t.t111ir@xxxxxxxxx>
To: "EnergyPlus_Support@xxxxxxxxxxxxxxx" <EnergyPlus_Support@xxxxxxxxxxxxxxx>
Sent: Friday, February 17, 2012 6:59 PM
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

Dr.Li now i found one thing i dont know is that correct or not

i found that what i mean from boiler is water heater

in my building boiler has burner or heater and has tank and thermometer that measured the water in the tank and if its temperature is greater than 80 then boiler will be on ,..

what i mean from water heater is coil exchanger that one side is connect to hot water and another is connect to cold water from main pipe , then this two tubes exchange Q from hot water and cold water ,...

but now i dont know from what class object i can simulate this heat exchanger ?

thanks

From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Friday, February 17, 2012 12:42 AM
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

T.T

I do not know how you add the schedules, etc.

If you use a text editor, all the manager and schedules can be kept together.

After you have written the manager and the controller, you will immediately follow by the set point schedule by copying the name from the controller to the schedule compact.

Then you will do a check, whether there is a schedule of the same name in the IDF.

If you follow these steps, you will be a good programmer as well.

Using the third party GUI will start your fast and the very difficult to expand your scope later on.
====================
This is my additional remarks for all the users of EPlus. Pay more attention to the IDF program entries and not just having pretity building pictures with many warnings and errors.

Dr. LI.

Dr. Li

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Thu, 16 Feb 2012 11:24:03 +0000
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

Dr.Li it is very strange i use setpoint manager for HW plant such as below :

HW supply Outlet Node, !- Loop Temperature Setpoint Node Name

HW Loop Temp Schedule, !- Schedule Name
HW supply Outlet Node; !- Setpoint Node or NodeList Name

Schedule:Compact,
    HW Loop Temp Schedule,   !- Name
    Temperature,             !- Schedule Type Limits Name
    Through: 12/31,          !- Field 1

For: Alldays, !- Field 2
Until: 24:00, 75; !- Field 4

the result are the same when i use

HW supply inlet Node, !- Loop Temperature Setpoint Node Name

i see in winter design day when inlet boiler temperature greater than 75 then it off the boiler in both case.

i dont undrestand why there is no differenc between them

thanks for your attention

From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Wednesday, February 15, 2012 3:16 AM
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

I do not understand your question or the purpose of the moving of the pump position.

In your PDF diagram, the pump is in the orage coloured pipe, lower temperature return pipe. This is the position in the SVG diagram, and is the recommended branch ordering.

It is possible to move the pump to the demand side inlet, but you should ask the support group, if the simulation fails.

The SVG diagram looks fine, although it is not the usual view, which begins with a pump without a by-pass path.

The Winter operation seems correct.

Dr. Li

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Tue, 14 Feb 2012 09:16:33 +0000
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

Dear Dr.Li ,

could you please see the file that i attached it ?

there is pump as first object in supply side in example files of energyplus , i want to know there is problem if i use pump after water heater ?

there is no problem in energyplus simulation that i use bypass with pump ?

thanks

From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Saturday, January 28, 2012 4:08 AM
Subject: 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 65Â°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
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Cocoa, FL  32922-5703
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Fax:     (321) 638-1439 or 1010
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