Ground Heat Exchanger Modeling Developed for Energy Flows of an Incompressible Fluid
Ground-source heat pumps achieve higher efficiencies
than conventional air-source heat pumps because they exchange heat
with the ground that is cooler in summer and hotter in winter than the
air environment. Earth heat exchangers are essential parts of the
ground-source heat pumps and the accurate prediction of their
performance is of fundamental importance. This paper presents the
development and validation of a numerical model through an
incompressible fluid flow, for the simulation of energy and
temperature changes in and around a U-tube borehole heat
exchanger. The FlexPDE software is used to solve the resulting
simultaneous equations that model the heat exchanger. The validated
model (through a comparison with experimental data) is then used to
extract conclusions on how various parameters like the U-tube
diameter, the variation of the ground thermal conductivity and
specific heat and the borehole filling material affect the temperature
of the fluid.
[1] H. S. Carslaw and J. C. Jaeger, Conduction of heat in solids, Claremore
Press, Oxford, 1946.
[2] V. C. Mei and C. J. Emerson, "New approach for analysis of groundcoil
design for applied heat pump systems," ASHRAE Transactions
91(2B), 1985, pp. 1216-1224.
[3] J. D. Deerman and S. P. Kavanaugh, "Simulation of vertical U-tube
ground coupled heat pump systems using the cylindrical heat source
solution," ASHRAE Transactions 97(1), 1991, pp. 287-295.
[4] C. Yavuzturk, J. D. Spitler and S.J. Rees, "A Transient two-dimensional
finite volume model for the simulation of vertical U-tube ground heat
exchangers," ASHRAE Transactions 105(2), 1999, pp. 465-474.
[5] Y. Nam, R. Ookaa and S. Hwanga, "Development of a numerical model
to predict heat exchange rates for a ground-source heat pump system,"
Energy and Buildings 40(12), 2008, pp. 2133-2140.
[6] P. Cui, H. Yang and Z. Fang, "Numerical analysis and experimental
validation of heat transfer in ground heat exchangers in alternative
operation modes," Energy and Buildings 40(6), 2008, pp. 1060-1066.
[7] L. Schiavi, "3D Simulation of the Thermal Response Test in a U-tube
Borehole Heat Exchanger," in Proc. COMSOL Conference, Milan,
2009. On line: http://cds.comsol.com/access/dl/papers/6825/Schiavi.pdf
[8] J. C. Heinrich and D. W. Pepper, Intermediate finite element method:
Fluid flow and heat transfer applications, Taylor & Francis,
Philadelphia, PA, 1999.
[9] G. Florides and S. Kalogirou, "First in situ determination of the thermal
performance of a U-pipe borehole heat exchanger in Cyprus," Applied
Thermal Engineering 28(2-3), 2008, pp. 157-163.
[1] H. S. Carslaw and J. C. Jaeger, Conduction of heat in solids, Claremore
Press, Oxford, 1946.
[2] V. C. Mei and C. J. Emerson, "New approach for analysis of groundcoil
design for applied heat pump systems," ASHRAE Transactions
91(2B), 1985, pp. 1216-1224.
[3] J. D. Deerman and S. P. Kavanaugh, "Simulation of vertical U-tube
ground coupled heat pump systems using the cylindrical heat source
solution," ASHRAE Transactions 97(1), 1991, pp. 287-295.
[4] C. Yavuzturk, J. D. Spitler and S.J. Rees, "A Transient two-dimensional
finite volume model for the simulation of vertical U-tube ground heat
exchangers," ASHRAE Transactions 105(2), 1999, pp. 465-474.
[5] Y. Nam, R. Ookaa and S. Hwanga, "Development of a numerical model
to predict heat exchange rates for a ground-source heat pump system,"
Energy and Buildings 40(12), 2008, pp. 2133-2140.
[6] P. Cui, H. Yang and Z. Fang, "Numerical analysis and experimental
validation of heat transfer in ground heat exchangers in alternative
operation modes," Energy and Buildings 40(6), 2008, pp. 1060-1066.
[7] L. Schiavi, "3D Simulation of the Thermal Response Test in a U-tube
Borehole Heat Exchanger," in Proc. COMSOL Conference, Milan,
2009. On line: http://cds.comsol.com/access/dl/papers/6825/Schiavi.pdf
[8] J. C. Heinrich and D. W. Pepper, Intermediate finite element method:
Fluid flow and heat transfer applications, Taylor & Francis,
Philadelphia, PA, 1999.
[9] G. Florides and S. Kalogirou, "First in situ determination of the thermal
performance of a U-pipe borehole heat exchanger in Cyprus," Applied
Thermal Engineering 28(2-3), 2008, pp. 157-163.
@article{"International Journal of Mechanical, Industrial and Aerospace Sciences:62404", author = "Paul Christodoulides and Georgios Florides and Panayiotis Pouloupatis and Vassilios Messaritis and Lazaros Lazari", title = "Ground Heat Exchanger Modeling Developed for Energy Flows of an Incompressible Fluid", abstract = "Ground-source heat pumps achieve higher efficiencies
than conventional air-source heat pumps because they exchange heat
with the ground that is cooler in summer and hotter in winter than the
air environment. Earth heat exchangers are essential parts of the
ground-source heat pumps and the accurate prediction of their
performance is of fundamental importance. This paper presents the
development and validation of a numerical model through an
incompressible fluid flow, for the simulation of energy and
temperature changes in and around a U-tube borehole heat
exchanger. The FlexPDE software is used to solve the resulting
simultaneous equations that model the heat exchanger. The validated
model (through a comparison with experimental data) is then used to
extract conclusions on how various parameters like the U-tube
diameter, the variation of the ground thermal conductivity and
specific heat and the borehole filling material affect the temperature
of the fluid.", keywords = "U-tube borehole, energy flow, incompressible fluid,
numerical model", volume = "6", number = "3", pages = "724-5", }