Re: [EnergyPlus_Support] VRF water-cooled condensers.

Hi,

I understand the warning message meaning. I have increased Heating Maximum Outdoor Dry-Bulb Temperature, but the Outdoor Dry-Bulb Temperature also incease.

** Warning ** AirConditioner:VariableRefrigerantFlow "VRF EXTERIORUNIT01 PBYP1".

** ~~~ ** ...InitVRF: VRF Heat Pump Min/Max Outdoor Temperature in Heating Mode Limits have been exceeded and VRF system is disabled.

** ~~~ ** ... Outdoor Dry-Bulb Temperature = 60.097

** ~~~ ** ... Heating Minimum Outdoor Dry-Bulb Temperature = -20.000

** ~~~ ** ... Heating Maximum Outdoor Dry-Bulb Temperature = 60.000

** ~~~ ** ... Check VRF Heat Pump Min/Max Outdoor Temperature in Heating Mode limits.

** ~~~ ** During Warmup, Environment=BARCELONA INVIERNO, at Simulation time=01/01 08:30 - 08:45

I am trying to simulate a VRF water condenser. In proyect, the water temperature is defined between 35ÂºC and 20ÂºC, so, I should include a boiler and a cooling tower in the condenser loop.

So, my doubt is Which is the Heating Min/Max Outdoor Dry-Bulb Temperature infuence in the VFR water condenser?

I am thinking the problem may lie the curves, because i am using the VRF example curves. Any other idea?

Have anyone an example for water condenser exterior unit curves?

thanks

De: YuanLu Li <yli006@xxxxxxxxxxx>
Para: EnergyPlus_Support <energyplus_support@xxxxxxxxxxxxxxx>
Enviado: MiÃ©rcoles 24 de octubre de 2012 21:45
Asunto: RE: [EnergyPlus_Support] VRF water-cooled condensers.

I have no idea how your system is operating.

** Warning ** AirConditioner:VariableRefrigerantFlow "VRF EXTERIORUNIT01 PBYP1".

** ~~~ ** ...InitVRF: VRF Heat Pump Min/Max Outdoor Temperature in Heating Mode Limits have been exceeded and VRF system is disabled.

** ~~~ ** ... Outdoor Dry-Bulb Temperature = 35.077

** ~~~ ** ... Heating Minimum Outdoor Dry-Bulb Temperature = -20.000

** ~~~ ** ... Heating Maximum Outdoor Dry-Bulb Temperature = 35.000

** ~~~ ** ... Check VRF Heat Pump Min/Max Outdoor Temperature in Heating Mode limits.

** ~~~ ** During Warmup, Environment=BARCELONA INVIERNO, at Simulation time=01/01 19:00 - 19:15

The warning message is clera. 35.077 is larger than 35.00.

Outdoor dry bulb temperature is your environment temperature.

Dr. Li

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: omartabuyo@xxxxxxxxx
Date: Wed, 24 Oct 2012 18:56:07 +0100
Subject: Re: [EnergyPlus_Support] VRF water-cooled condensers.

i used you advice to build the model, but when running this warning is showed:

** Warning ** AirConditioner:VariableRefrigerantFlow "VRF EXTERIORUNIT01 PBYP1".

** ~~~ ** ...InitVRF: VRF Heat Pump Min/Max Outdoor Temperature in Heating Mode Limits have been exceeded and VRF system is disabled.

** ~~~ ** ... Outdoor Dry-Bulb Temperature = 35.077

** ~~~ ** ... Heating Minimum Outdoor Dry-Bulb Temperature = -20.000

** ~~~ ** ... Heating Maximum Outdoor Dry-Bulb Temperature = 35.000

** ~~~ ** ... Check VRF Heat Pump Min/Max Outdoor Temperature in Heating Mode limits.

** ~~~ ** During Warmup, Environment=BARCELONA INVIERNO, at Simulation time=01/01 19:00 - 19:15

Anyone kown how i can solve it? Which is the Heating Min/Max Outdoor Dry-Bulb Temperature infuence in the VFR water condenser?

thanks

De: Richard Raustad <RRaustad@xxxxxxxxxxxx>
Para: EnergyPlus_Support@xxxxxxxxxxxxxxx
Enviado: Lunes 22 de octubre de 2012 19:01
Asunto: Re: [EnergyPlus_Support] VRF water-cooled condensers.

Yes, use a single plant loop to serve the VRF condenser.
Here's a file I have been playing with.
The imf file is the building and VRF system.
The idf is the plant loop.
The in.idf file is these two files after EPMacro assembles them together.

On 10/22/2012 12:47 PM, Omar Tabuyo wrote:

Dear all,

I am trying to simulate a VRF water condenser. I know that you can do it with version 7.2. In proyect, the water temperature is defined between 35ÂºC and 20ÂºC, so, I should include a boiler in the condenser loop.

Is this configuration possible today in energyplus? Anyone know how i can simulate it?

Thanks in advance

-- 
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