Re: [TRNSYS-users] Borehole

[Ben Heymer <bheymer@gmail.com>]

Atli Thor Olason,

That's a great question.

I have performed several single-borehole dynamic thermal response
tests in the Chicago area and used the data to calibrate type 557a.
Since my goal was to understand how larger, multiple bore,
installations would perform I set the storage volume based on 6 m
center-to-center spacing, which is typical for final installations in
this area. After calibrating conductivity and heat capacity I was able
to achieve very accurate tracking between the model and real
single-bore data. I did not try varying the storage volume but I
suspect that the mathematical model is able to produce accurate
results over a range of storage volume values, given the many
non-orthogonal input parameters.

I would recommend that you test the sensitivity of the storage volume
value (and other important parameters) as it relates to your
application. You may identify a worst-case result, a best-case result,
and several intermediate results.

In real applications I often recommend designing for the intermediate
or best case and providing supplemental systems to handle the worst
case. One GSHP system that I monitored for several years exceeded any
best-case estimate (probably due to high groundwater movement).

Best regards,
Ben Heymer, PE

On Wed, Nov 26, 2014 at 6:28 AM, Atli Thor Olason (164693)
<164693@via.dk> wrote:
> Hi all,
>
>
> Anyone had experience with type 557a? What is an appropriate amount of
> storage volume when you only have one borehole.
>
> the given formula in "more" assumes multiple boreholes.
>
>
> Thank you
>
> Atli Thor Olason
>
>
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