RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

[YuanLu Li <yli006@xxxxxxxxxxx>]

See my comments below.
 
 Dr. Li  

 

---

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Fri, 27 Jan 2012 22:04:28 +0000
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

 

Dear Dr.Li

Thanks a lot for your kind guides.

Please accept my apology for any inconvenience.

 

Plant in Iran:

In Iran there is no automatic thermostat which could be as radiator controllers. In fact there are two stages: Designing, Simulation

If you do not have a real building, all you are saying may be text book description.

Therefore, I gave you a real system in London, England in the mail to follow.

 

First of all we suppose that the ideal zone temperature is 20 degree Celsius in year.

Then base on the coolest day in a year we arrange capacity of boiler.

Indeed boiler controls radiator for turning on or off. In this case, because of we don?t have any control on air zone temperature most of the time the temperature becomes more than 20 degree Celsius and perhaps radiator is on. As well as thermostat is utilized on hot-water pump in multi-story buildings for controlling water temperature. In this type of building the boiler and pump are on and off consecutively.

This is the reason why you use EPlus simulation to determine the size of the heat requirement using the DesignDay sizing and compare with the TMY annual conditions.

 

I have some question:

 

Could you please tell me can I simulate the building without any controlling on room temperature by using Energyplus software?

Yes, this is known as the natural state of the building.

 

I suggest two ways:

 

1)      By decreasing convergence tolerance baseboard

2)      Arrange the thermostat at high temperature that the boiler with maximum capacity could not be able to produce this temperature. As well as maximum capacity of boiler is considered as input of software.

Run an example or the exercise in the Getting Started PDF of the EPlus.  Not the Getting Strted  from the third party software providers.  Then you may know what to add.  If you are not a programmer, the source code would not help you.

 

Should I change the source code of Energyplus If there is no solution?

I have not seen you IDF, therefore I cannot comment.

I do not think you can change the source code of EnergyPlus.  May be two or three years from now, after learning how to use Fortran, code, compile, link or made into an excutable file on your PC, or any OS platform.

 

Could you please tell me which module should I read?

I do not think you can understand EPlus simulation by reading the source file.  I can, as I have been doing it since 1960.

 

 

I would be appreciated if you would consider my problem.

Your problem is not complex, if you have a actual system to model.  Because your description of the system is not correct, the IDF cannot be easily generated.

 

Water heated baseboard zone system is the nearest example.  Unfortunately, this example file may be been removed, as it is too simple.  The exercise in the Getting Started is now too complex for a beginner, but if you can follow it, you will have less problem.

 

 

 

I am looking forward to hearing from you

With the best wishes

Tooran

From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Friday, January 27, 2012 10:21 PM
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

 

Run the IDF and see what happens.
 
Raditor is a zone equipment and is in the air loop or path.  The zone thermostat would turn it off.  
 
There is no need to control the fire or heater.  The tank temperature range will look after that. Sizing:Plant object default values are not the same as yours.

The temperature at the input of the pump is not defined.  If you must have that temperature at 65°C, use the EMS control.
 
Otherwise, the tank water at 65°C will turn on the heater automatically.   I do not think that your Iran system has a thermostat at the input of the pump to turn on the heater.
 
Why do you want to turn off the pump when the temperature is greater than 65°C?   Heater turns on, and pump goes off.  Does not make sense.
 
Run the IDF and plot the temperatures on your schematics and see what you have got.
 
Once you have entered  80 and 15 = 80 - 65 in the sizing:plant, that is all you need.  If you want to stop the radiator from rising above 65°C, that is different control.  Simply change 80 to 65 and use the default range.  As you now have the Fortran source, you can see how the program operates.
 
 Dr. Li  

 

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: t.t111ir@xxxxxxxxx
Date: Fri, 27 Jan 2012 18:34:20 +0000
Subject: Re: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

 

As Dr.Li Say i want to use the availabilityManager:HightemperaturTurnoff  to turn the heater off at 80°C tank temperature
but not  The radiator would be turned off at 20°C, and the water would go through the by-pass path. but there is no control to turn off the radiator , we dont have automatic direct control on radiator .

you know there is building in tehran : at first we designing the plant and we assume the ideal air temperature for zone is 20C then we designin the plant for coldest day at winter , and determine what capacity  boiler must be . plant is central heating there is natural gas boiler when thermostat boiler  will on boiler works with full capacity ., constant pump and alminum radiator and there is no automatic thermostat on radiator so we have no direct control on  zone air temperature .

 

 and also The second thermometer not at the inlet of the tank  there is at inlet the pump  to control the pump at 65°C   . 

so now i think  with richard and Dr.Li describing i think i can use setpoint temperature for boiler and availability manager for pump

to control inlet temperature of pump and outlet temperature of boiler .

is that right?

 

and at the end i appologise for my language

 

thanks

From: YuanLu Li <yli006@xxxxxxxxxxx>
To: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Sent: Friday, January 27, 2012 9:25 PM
Subject: RE: [EnergyPlus_Support] availabilityManager:High temperaturTurnoff

 

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

__._,_.___

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

__,_._,___