Calculation algorithm of the temperatures for pipe arrangement of multiple ground heat exchangers

Optimization of energy extraction for closed shallow geothermal systems using linear programming

“…Accordingly, in the well established BHE designing tools EED (Hellström and Sanner, 1997), and GLHEPRO (Spitler, 2000) the volumetric flow rate per borehole is uniformly distributed by the number of BHEs. A constant volumetric flow rate of the heat carrier can also be found in analytical and numerical simulation studies or performance investigations of multiple BHEs (Urchueguía et al, 2008;Katsura et al, 2009).…”

“…If a single BHE is not sufficient to supply the energy required for a specific case, BHE fields are constructed, and the total BHE length is oriented at the total energy demand. Depending on the specific case and available space, simple geometric arrangements such as square or longitudinal lattices are commonly selected (Fujii et al, 2005;Katsura et al, 2008Katsura et al, , 2009). Usually, a distance of a few meters is considered sufficient to minimize mutual interference of adjacent BHEs, for example, from 3 m in China and up to 10 m in Germany (Kavanaugh and Rafferty, 1997;Signorelli et al, 2004;Haehnlein et al, 2010).…”

A composite cylindrical model and its application in analysis of thermal response and performance for energy pile

“…Park et al [9] made numerical and analytical case study of thermal response test with energy pile and indicated that analytical models, including modified solutions in the study, overestimated temperature rises outside the pile. The discrepancies might be induced by [10] carried out field tests of heating and heat extraction of a GSHP system using 25 steel foundation piles of 8 m long as ground heat exchangers. Performance of GSHP systems with steel foundation piles in long term was predicted with the developed tool.…”

G-Functions for multiple interacting pile heat exchangers

“…Calculation of the exact inlet and outlet temperature to each individual pile is therefore very time consuming. Fortunately Katsura et al [22] have shown that simplifications, including assuming each series circuit acts as one heat exchanger, provide sufficiently accurate results. Providing the piles are all the same geometry, this is effectively the same as assuming all individual heat exchangers operate in parallel.…”

“…It also claims to be more applicable to piles of larger diameter, but further details are not given [20]. Similar superposition approaches can be taken with cylindrical source models, eg [21], [22] or equally any other single heat exchanger G-functions.…”