[TRNSYS-users] questions about ground source heat pump system using type668

[David Bradley]

Dear Jiang Shuang

>(1)I use type515 and type14 combined with an equation to control the 
>water-to-water heat pump. When the heating signal is 1, it works under 
>heating mode, and when the cooling signal is 1, it works under cooling 
>mode. However, I find that when both heating signal and cooling signal 
>change to 0, the heat pump stop working, but it still has a power output! 
>I have used the control part to a water-source heat pump, and all 
>components work well.

unless I am mistaken, this was a bug in the initial release of the TESS 
Libraries 2.0.00. It was fixed in the release of 2.0.01. You should contact 
your distributor to get the latest version of the appropriate DLL.

>(2)I find the example about type668 given in trnsys is about hot water 
>producing and more examples in the internet are also about heating. But in 
>my country, it is common that ground source heat pump is used to produce 
>chilled water and hot water to air conditioners in a building, in which 
>they exchange heat with the outdoor air. Then the airs are distributed to 
>rooms. My question is that if type668 can be used for the above purpose. 
>If not, which type should I choose?

yes, certainly. Type668 simply models a  water to water heat pump. The 
control signals can be set up to take energy from the ground and use it to 
heat load side water (heating mode) or to reject energy to the ground and 
cool load side water (cooling mode).

>(3) The vertical u-tubes (type557) has a parameter: number of boreholes in 
>series, what does it mean? If there are many series parallel loops (It is 
>common in practice), what should I do?

Type557 parameter 4 asks you to specify the total number of boreholes in 
the entire storage volume of earth. Parameter 6 asks you to specify the 
number of boreholes in series per parallel loop. Based on these two values, 
Type557 internally calculated how many parallel loops there are in your field.

Kind regards,
   David


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Thermal Energy System Specialists (TESS), LLC
David BRADLEY                           2916 Marketplace Drive - Suite 104
Partner                                        Madison, WI 53719
Phone: (608) 274-2577 USA
Fax: (608) 278-1475
E-mail: bradley at tess-inc.com
Web Pages:  http://www.tess-inc.com     and      http://www.trnsys.com

"Providing software solutions for today's energy engineering projects"
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