×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Large (5 MBtuh+ ) heat pump application

Large (5 MBtuh+ ) heat pump application

Large (5 MBtuh+ ) heat pump application

(OP)
Is anyone aware of large scale (5 million btus/hr +) heat pumps in the US?  The application in question is heating of hot water with a fairly consistent year round demand.
Gas prices in my area have doubled in the last few years and we are forecasting 20% higher ($10 / DTH) in the next year whereas electricity has been cheap and plentiful ($.037/kwhr).

On paper it appears valid (COP of 3, NH3).

RE: Large (5 MBtuh+ ) heat pump application

I think you're asking about a water source heat pump?  or reverse cycle chiller?  Trane has them, as does Milti-Stack.  Those are two options that I am aware of.

Jabba

RE: Large (5 MBtuh+ ) heat pump application

(OP)
Either.

Water source is possible given incoming water temperatures but most water is heated which would offset or completely negate the benefit.
 

RE: Large (5 MBtuh+ ) heat pump application

How hot does the water need to be?  

The Multi-Stack chiller guys in my area are beating the bushes like crazy touting the benefits of the energy recovery chillers, and pitch them as first stage heat in a situation where you can ground couple them.  I think that the LWT on them is limited to about 125F though I am not SURE of that number.

Jabba

RE: Large (5 MBtuh+ ) heat pump application

I have seen a project where an air cooled McQuay chiller was used as a heat pump to provide domestic hot water.

RE: Large (5 MBtuh+ ) heat pump application

Are you interested in hot water generation only, or reducing natural gas loading?

I think Ft Gordon, GA (or it might be Stewart) has a large closed loop system-the DOE FEMP site has a story on it.

I'm looking into the same thing for the same conditions. Looking into feasibility of domestic hot water generation during summer to reduce summer boiler load for DHW by zoning geoexchange heap pumps on a secondary loop. Generating DHW would make a good heat sink.

Mostly have air side economizers, so the chiller plant doesn't run when its cold out. Still, with a year round watr source of 55-60 F and a high COP, I'm expecting the life cycle cost to pay off.
 

RE: Large (5 MBtuh+ ) heat pump application

(OP)
Both.  We have the need for the hot water generation and the savings is realized in reduced natural gas expenditures.

I've spoken with a compressor MFR and this looks very feasible.  Much better COP than I was expecting.

RE: Large (5 MBtuh+ ) heat pump application

I have seen McQuay water cooled heat pump, using the plant condenser water as a heat source.  Double benefit.
 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources