Hybrid GSHP

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Dear All,

At present I am working on a project using Hybrid GSHP. A cooling tower is attached to the ground heat exchanger loop to balance the uneven heating and cooling load. Does anyone meet this problem before? Any suggestions? Thanks a lot!

Aaron

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Aaron,

Recently I?ve introduced myself to a great free program that I plan to use alongside my next eQuest project involving a GLHX. The program, referenced in the eQuest help files, is GS2000 and is produced and distributed by some arm of the Canadian government.

This program lets you, after learning about the parameters of borefield design, model the thermal (not energy) behavior of an actual GLHX. There is a good degree of better control over all of the variables than the eQuest wizards offer.

When all is said and done, you get results that evaluate your design over a 10-year period, observing the effects of adding a heat rejection equipment if you choose to, and it also spits out the monthly average loop temperatures. The heat rejection equipment has some limited flexibility in defining its schedule (seems like you just get to say which months of the year it runs, presumeably continuously). As a side benefit, you get a real feel of how large such a fluid cooler needs to really be, and what the economic implications are vs. just doing a larger well field.

I?d suggest as an option to try this, then making a well loop in eQuest assigning a custom temperature schedule using the monthly averages output of GS2000. If you give some attention to ensuring your heatpump curves and your cooling tower operating schedule is well defined in relation to those temperatures, I think you?ll be set to model the actual system performance pretty accurately.

I?ll point out that while I?ve dealt with the ins and outs of modeling GLHX systems in eQuest (you?ll find at least a few posts searching for my name), I can?t say with certainty that there is no method of modeling cooling tower effects on a GLHX loop entirely within eQuest as I haven?t tried it yet?

Are you getting an error when trying to attach the tower to the loop? Is the attachment ?working? but you?re not seeing any effects on the loop temperatures? Let us as a community know what you?ve tried and what?s not working more specifically, and you?ll be sure to get more timely/specific advice ;).

NICK CATON, E.I.T.

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