Method for operating an arrangement for storing thermal energy

• US 9,657,998 B2
• Filed: 11/01/2013
• Issued: 05/23/2017
• Est. Priority Date: 11/01/2012
• Status: Expired due to Fees

• Current Assignee: Skanska Sverige AB (Skanska AB)
• Original Assignee: Skanska Sverige AB (Skanska AB)
• Inventors: Strand, Tobias, Pilebro, Hans
• Primary Examiner(s): CIRIC, LJILJANA V
• Application Number:
  US14/439,760
• Publication Number:
  US 20150292809A1
• Time in Patent Office: 1,299 Days
• Field of Search: 165 45
• CPC Class Codes: F24D 19/1066 for the combination of central heating and domestic hot water
• CPC Class Codes: F24D 2200/11 Geothermal energy
• CPC Class Codes: F24D 2200/123 Compression type heat pumps
• CPC Class Codes: F24D 3/08 in combination with systems for domestic hot-water supply
• CPC Class Codes: F28D 20/0034 using liquid heat storage material
• CPC Class Codes: F28D 20/0039 with stratification of the heat storage material
• CPC Class Codes: F28D 20/0052 using the ground body or aquifers as heat storage medium
• CPC Class Codes: F28D 2020/0069 Distributing arrangements; Fluid deflecting means
• CPC Class Codes: Y02B 10/40 Geothermal heat-pumps
• CPC Class Codes: Y02E 60/14 Thermal energy storage
• CPC Class Codes: Y02P 80/15 On-site combined power, heat or cool generation or distribution, e.g. combined heat and power [CHP] supply

Abstract

A method for operating an arrangement (1) for storing thermal energy where the arrangement (1) includes an energy storage (2) having a temperature gradient. The method involves retrieving energy at a first temperature (T₁) from the energy storage (2) for use in a first heat-absorbing system (3), such that free space is created in the energy storage (2) for energy at a second temperature (T₂). The second temperature (T₂) is higher than the first temperature (T₁).

Claims

1. A method for operating an arrangement (1) for storing fluid, said arrangement (1) comprising an underground energy storage (2) having a vertical temperature gradient, which method comprises

retrieving fluid at a first temperature (T₁) from the energy storage (2) for use in a first heat-absorbing system (3) located above ground, such that free space is created in said energy storage (2) for fluid at a second temperature (T₂), wherein said second temperature (T₂) is higher than said first temperature (T₁),

retrieving fluid at said second temperature (T₂) from the energy storage (2) for use in a second heat-absorbing system (4) located above ground,

providing fluid at said second temperature (T₂) to a level of said energy storage (2) being at said second temperature (T₂),

wherein the method further comprises

retrieving fluid at a third temperature (T₃) from said energy storage (2) for use in a heat emitting cooling system (8) located above ground, and

providing fluid at a said third temperature (T₃), which is lower than said first and second temperatures (T₁, T₂), to a level of said energy storage (2) being at said third temperature (T₃),

wherein said first heat-absorbing system (3) is configured to operate at a lower temperature than said second heat-absorbing system (4).

2. The method according to claim 1, further comprising receiving fluid at said third temperature (T₃) from said first heat-absorbing system (3) and providing said fluid at a level of said energy storage (2) being at said third temperature (T₃).

3. The method according to claim 1, further comprising receiving fluid at said second temperature (T₂) from a heat-emitting system (6, 7), and providing said fluid at a level of said energy storage (2) being at said second temperature (T₂).

4. The method according to claim 1, further comprising receiving fluid at said first temperature (T₁) from a heat-emitting system (6, 7), and providing said fluid at a level of said energy storage (2) being at said first temperature (T₁).

5. The method according to claim 1, further comprising receiving fluid at said first temperature (T₁) from said second heat-absorbing system (4) and providing said energy at a level of said energy storage (2) being at said first temperature (T₁).

6. The method according to claim 1, further comprising receiving fluid at said first temperature (T₁) from said heat emitting cooling system (8) and providing said fluid at a level of said energy storage (2) being at said first temperature (T₁).

7. The method according to claim 1, further comprising receiving fluid from an exterior (13, 14) of said arrangement (1), and providing said energy at a level of said energy storage (2) being at said third temperature (T₃).

8. The method according to claim 1, wherein said first temperature (T₁) is in the range of 15°

C. to 65°

C.

9. The method according to claim 1, wherein said second temperature (T₂) is in the range of 50°

C. to 100°

C.

10. The method according to claim 1, wherein said third temperature (T₃) is in the range of 4°

C. to 25°

C.

11. The method according to claim 1, wherein vertical temperature stratification is used in the energy storage (2) in order to generate a gradient flow due to differences in density between vertical levels, wherein warm water flows upwards through the energy storage to a heat exchanger where it is cooled down, and colder water flows downward through the energy storage.