1 / 23

OPTIMIZATION OF GROUND COUPLED HEAT PUMP SYSTEMS

Akademiska Hus Carrier CTC / Enertech Donghua University Fastighetsägarna Geotec Grundfos IVT LTH NCC Nibe SWECO TAC Thermia Värme Wilo ÅF- Infrastruktur. OPTIMIZATION OF GROUND COUPLED HEAT PUMP SYSTEMS. Saqib Javed (PhD Researcher) Per F ahlén (Research Leader)

gaerwn
Télécharger la présentation

OPTIMIZATION OF GROUND COUPLED HEAT PUMP SYSTEMS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Akademiska Hus Carrier CTC / Enertech Donghua University Fastighetsägarna Geotec Grundfos IVT LTH NCC Nibe SWECO TAC ThermiaVärme Wilo ÅF-Infrastruktur OPTIMIZATION OF GROUND COUPLED HEAT PUMP SYSTEMS Saqib Javed (PhD Researcher) Per Fahlén (Research Leader) Johan Claesson (Supervisor) EFFSYS 2 meeting 2009-12-14

  2. objective • Identifying key optimization factors for Ground Coupled Heat Pump (GCHP) systems using modelling, simulations field studies and experiments. • Developing simple and user-friendly models and calculation tools to facilitate designers and researchers interested in the complete system optimization. EFFSYS 2 meeting 2009-12-14

  3. Literature review • Single boreholes: Long term response can be modelled using simple existing analytical models with reasonable accuracy. • Multiple boreholes: Shortage of analytical models for both long and short term response. • Need of an analytical model which: • is capable of simulating both short-term and long-term response of GHE. • considers all significant heat transfer processes in GHE. • retains the actual geometry of the borehole. EFFSYS 2 meeting 2009-12-14

  4. Case study • Astronomy-House, Lund University • Floor area: 5300 m2 • Heating demand: 475 MWh • Cooling demand: 155 MWh • Ground system • 20 boreholes • Rectangular configuration • Each 200 m deep EFFSYS 2 meeting 2009-12-14

  5. Simulating MULTIPLE BOREHOLES Tb = brine temperature Tw = borehole wall temperature Tp = temperature penalty from neighbouring boreholes EFFSYS 2 meeting 2009-12-14

  6. MEAN BRINE TEMPERATURES EFFSYS 2 meeting 2009-12-14

  7. publications • Javed, S., Fahlén, P. and Holmberg, H., 2009. Modelling for optimization of brine temperature in ground source heat pump systems. Proceedings of 8th international conference on sustainable energy technologies; SET2009, Aachen, Germany. August 31- September 3. • Javed, S., Fahlén, P. and Claesson, J., 2009. Vertical ground heat exchangers: A review of heat flow models. Proceedings of 11th international conference on thermal energy storage; Effstock 2009, Stockholm, Sweden. June 14-17. • Fahlén, P, 2008. Efficiency aspects of heat pump systems - Load matching and parasitic losses. IEA Heat pump centre Newsletter, vol. 26, nr. 3, 2008-08, (IEA.). EFFSYS 2 meeting 2009-12-14

  8. Literature review • Single boreholes: Long term response can be modelled using simple existing analytical models with reasonable accuracy. • Multiple boreholes: Shortage of analytical models for both long and short term response. • Need of an analytical model which: • is capable of simulating both short-term and long-term response of GHE. • considers all significant heat transfer processes in GHE. • retains the actual geometry of the borehole. EFFSYS 2 meeting 2009-12-14

  9. modelling • Existing Analytical models: • Equivalent pipe / cylinder instead of a U-tube. • Thermal capacities of the water and the pipe are often ignored. • Response is a function only of the distance (r) from the centre of the equivalent pipe. EFFSYS 2 meeting 2009-12-14

  10. modelling • New Analytical models: • Two pipes in the ground. • Accounts for the thermal short circuiting between the two legs of the U-tube. • Response is a function of both x and y. • Can predict the short time response accurately. EFFSYS 2 meeting 2009-12-14

  11. modelling • New Analytical models: • Two pipes in the grout surrounded by the ground. • Accounts for the thermal properties of both the grout and the ground. EFFSYS 2 meeting 2009-12-14

  12. modelling • New Numerical model: • Solved the heat transfer problem in 2D using conformal coordinate system. • Used for the validation of the analytical model. EFFSYS 2 meeting 2009-12-14

  13. Literature review • Single boreholes: Long term response can be modelled using simple existing analytical models with reasonable accuracy. • Multiple boreholes: Shortage of analytical models for both long and short term response. • Need of an analytical model which: • is capable of simulating both short-term and long-term response of GHE. • considers all significant heat transfer processes in GHE. • retains the actual geometry of the borehole. EFFSYS 2 meeting 2009-12-14

  14. experiments • Development of a test facility. • Experiments to determine: • Thermal response for heat extraction and injection conditions. • Flow effects. • System effects. • Validation of the developed models. EFFSYS 2 meeting 2009-12-14

  15. Laboratory development EFFSYS 2 meeting 2009-12-14

  16. Laboratory development EFFSYS 2 meeting 2009-12-14

  17. Brine & chilled water system EFFSYS 2 meeting 2009-12-14

  18. Hot water system EFFSYS 2 meeting 2009-12-14

  19. Ground heat exchanger system EFFSYS 2 meeting 2009-12-14

  20. Thermal response testing EFFSYS 2 meeting 2009-12-14

  21. Initial results • Ground thermal conductivity: 3 W/m-K • Undisturbed ground temperature: 9 °C EFFSYS 2 meeting 2009-12-14

  22. conclusions • Conducted a state-of-the-art literature review. • Presented different approaches to model multiple borehole systems. • Developing new analytical and numerical methods. • Carrying out experiments. EFFSYS 2 meeting 2009-12-14

  23. Questions / commentsThank you! EFFSYS 2 meeting 2009-12-14

More Related