The main problem with your schematic diagram is to have the boiler feeding the tank directly and the tank has multiple connection on the tank itself. This is not the usual tank model in EPlus.
An EPlus heater or storage tank has a source side and a use side, each represented as a coil (Heat Exchanger) to connect to the pipes. The volume of the tank is used for heat storage calculation. Just like the zone air, the air itself does not actually move. Each tank is model as two or three heat exchangers. The tank can ecahne heat with the environmen/zone. When the volume is zero, the source heat is coupled to the use side instantaneously. (See Figure 118 of the I/O manual.) Search the object names in this section to see the other parts of the system.
I think, your schematic is basically a DHW system, with the solar collector added. Water level control, pressure control, and other safety elements in your diagram are not simulated in EPlus.
You may use the same boiler to heat another small tank for the SHW loop, if the demand is too large.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: direzionecontraria@xxxxxxxx
Date: Wed, 18 Jul 2012 09:14:59 +0000
Subject: [EnergyPlus_Support] Re: connections of the hot water storage tank
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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.
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An EPlus heater or storage tank has a source side and a use side, each represented as a coil (Heat Exchanger) to connect to the pipes. The volume of the tank is used for heat storage calculation. Just like the zone air, the air itself does not actually move. Each tank is model as two or three heat exchangers. The tank can ecahne heat with the environmen/zone. When the volume is zero, the source heat is coupled to the use side instantaneously. (See Figure 118 of the I/O manual.) Search the object names in this section to see the other parts of the system.
I think, your schematic is basically a DHW system, with the solar collector added. Water level control, pressure control, and other safety elements in your diagram are not simulated in EPlus.
You may use the same boiler to heat another small tank for the SHW loop, if the demand is too large.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: direzionecontraria@xxxxxxxx
Date: Wed, 18 Jul 2012 09:14:59 +0000
Subject: [EnergyPlus_Support] Re: connections of the hot water storage tank
Thank you. Do you suggest some particular chapters of the EnergyPlus documentation in order to learn and to understand what is and is not allowed in my case?
Best Regards
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Jean marais" <jeannieboef@...> wrote:
>
> No easy answere. In eplus there are some rules on what configurations are allowed in the plant loops and demand side loops. Don't dive in and try to replicate your schematic 1 to 1. Learn and understand what is and is not allowed otherwise you will only get hours of frustration. You will find that some of the nodepoints will shift around. Pumps may fall away for numerical stabillity and their effects lumped into other pumps. All your branches will end up in parallel arangements from the mixers and splitters (watch out for correct branch ordering). If you have to do this 1 to 1, then use TrnSys. You will sacrifice a bit from the building model goodness of eplus, but seeing that Trnsys was developed from the solar equipment modelling industry side, it may be the perfect tool for this job.
>
> Else, if your aim is building orientated as apposed to machine, then you will find that the restrictions of loops, are not that sensitive to the outcomes of annual building energy usage.
>
>
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "FrancescoP" <direzionecontraria@> wrote:
> >
> > As you can see in the image http://img607.imageshack.us/img607/5029/hwdhwsolar.jpg
> > I'm modelling a HVAC plant in which a hot water storage tank is connected with a boiler (hot water is produced by the combustion of natural gas), a solar thermal loop, the hot water loop, and the domestic water loop. Therefore the network of inlet and outlet nodes is quite complicated.
> > The "Water Heater Configuration" of EnergyPlus (Figure 65 of input/output Reference) seems much more schematic.
> > Do you have any suggestion for my modelling work, please? Should I work with nodes, splitters, and mixer (e.g. the connection of the hot water storage tank with the HW loop and with the DHW loop could be common and then a splitter could divide the HW loop from the DHW loop)?
> > Best Regards
> >
>
Best Regards
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Jean marais" <jeannieboef@...> wrote:
>
> No easy answere. In eplus there are some rules on what configurations are allowed in the plant loops and demand side loops. Don't dive in and try to replicate your schematic 1 to 1. Learn and understand what is and is not allowed otherwise you will only get hours of frustration. You will find that some of the nodepoints will shift around. Pumps may fall away for numerical stabillity and their effects lumped into other pumps. All your branches will end up in parallel arangements from the mixers and splitters (watch out for correct branch ordering). If you have to do this 1 to 1, then use TrnSys. You will sacrifice a bit from the building model goodness of eplus, but seeing that Trnsys was developed from the solar equipment modelling industry side, it may be the perfect tool for this job.
>
> Else, if your aim is building orientated as apposed to machine, then you will find that the restrictions of loops, are not that sensitive to the outcomes of annual building energy usage.
>
>
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "FrancescoP" <direzionecontraria@> wrote:
> >
> > As you can see in the image http://img607.imageshack.us/img607/5029/hwdhwsolar.jpg
> > I'm modelling a HVAC plant in which a hot water storage tank is connected with a boiler (hot water is produced by the combustion of natural gas), a solar thermal loop, the hot water loop, and the domestic water loop. Therefore the network of inlet and outlet nodes is quite complicated.
> > The "Water Heater Configuration" of EnergyPlus (Figure 65 of input/output Reference) seems much more schematic.
> > Do you have any suggestion for my modelling work, please? Should I work with nodes, splitters, and mixer (e.g. the connection of the hot water storage tank with the HW loop and with the DHW loop could be common and then a splitter could divide the HW loop from the DHW loop)?
> > Best Regards
> >
>
__._,_.___
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.
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