INSTALLATION FOR STORING THERMAL ENERGY

• US 20140224447A1
• Filed: 09/24/2012
• Published: 08/14/2014
• Est. Priority Date: 09/29/2011
• Status: Active Grant

• Current Assignee: Siemens Gamesa Renewable Energy A/S (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Reznik, Daniel, Stiesdal, Henrik
• Granted Patent: US 9,829,254 B2
• Time in Patent Office: Days
• US Class Current: 165/10
• CPC Class Codes: F01K 3/12 having two or more accumulators
• CPC Class Codes: F03D 9/18 storing heat
• CPC Class Codes: F03D 9/22 the apparatus producing heat
• CPC Class Codes: F28D 20/0056 using solid heat storage material F28D20/0052 takes precedence
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 60/14 Thermal energy storage
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

An installation for storing thermal energy is provided. The storage is carried out by the compression and relaxation of a working gas, wherein pump and compressor can be driven by, for example, electric motors which temporarily absorb excess power generated in the power grid. The generated thermal energy is temporarily stored in a cold accumulator and a heat accumulator. According to the invention, a vapor circuit is provided to connect to the heat accumulator and the cold accumulator for discharging the installation, by which a turbine for generating electrical energy can be driven by a generator. Said circuit is implemented by means of another conduit system distinct from the circuit for charging the installation. Advantageously, thermal energy generated from overcapacities in the power grid can thus be reconverted with high yield into electrical energy via a vapor circuit.

Claims

1. An installation for storing thermal energy, said installation comprising

a charging circuit for a working gas, wherein, in the charging circuit, the following units are connected to one another in the stated sequence by a first line for the working gas:

a first thermal fluid energy machine,

a heat accumulator and

a second thermal fluid energy machine,

wherein, as viewed in the throughflow direction of the working gas from the first thermal fluid energy machine to the second thermal fluid energy machine, the first thermal fluid energy machine is positioned as a work machine and the second fluid energy machine is positioned as a prime mover,

wherein the heat accumulator is connected, via a second line, into a discharging circuit for steam as working medium, wherein, in the discharging circuit, the following units are connected to one another in the stated sequence by the second line;

a pump,

the heat accumulator, and

a third thermal fluid energy machine positioned as a prime mover.

2. The installation as claimed in claim 1, wherein

the heat accumulator is traversed by flow in opposite directions in the charging circuit and in the discharging circuit.

3. The installation as claimed in claim 1, wherein

the heat accumulator has a first duct system connected to the first line and has an independent second duct system connected to the second line.

4. The installation as claimed in claim 3, wherein

the ratio of the volume of the first duct system to the volume of the second duct system is approximately inversely proportional to the ratio of the increase of the specific enthalpy in the first duct system during charging operation to the increase of the specific enthalpy in the second duct system during discharging operation.

5. The installation as claimed in claim 3, wherein

the first duct system and the second duct system are formed by pipes running parallel, wherein each pipe belonging to the first duct system runs adjacent to at least one pipe of the second duct system.

6. The installation as claimed in claim 1, wherein

the third thermal fluid energy machine is of at least two-stage construction with a high-pressure turbine and a low-pressure turbine.

7. The installation as claimed in claim 6, further comprising

a first closable bypass line connected in parallel with the high-pressure turbine in the second line.

8. The installation as claimed in claim 1, further comprising

a cold accumulator connected into the first line downstream of the second thermal fluid energy machine as viewed in the throughflow direction of the charging circuit.

9. The installation as claimed in claim 8, wherein

the cold accumulator is also connected into the second line downstream of the third thermal fluid energy machine as viewed in the throughflow direction of the discharging circuit.

10. The installation as claimed in claim 1, further comprising

an auxiliary heat accumulator connected between a fifth thermal fluid energy machine and a sixth thermal fluid energy machine by an auxiliary line, wherein, as viewed in the throughflow direction of the working gas from the fifth thermal fluid energy machine to the sixth thermal fluid energy machine, the fifth thermal fluid energy machine is positioned as a work machine and the sixth thermal fluid energy machine is positioned as a prime mover.

11. The installation as claimed in claim 10, wherein

the auxiliary heat accumulator is also connected into the first line upstream of the first thermal fluid energy machine as viewed in the throughflow direction of the charging circuit.

12. The installation as claimed in claim 10, wherein

the auxiliary heat accumulator is also connected into the second line upstream of the heat accumulator as viewed in the throughflow direction of the discharging circuit.

13. The installation as claimed in claim 6, further comprising

a second closable bypass line is connected into the second line in parallel with respect to the heat accumulator.

14. The installation as claimed in claim 1, wherein the third thermal fluid energy machine is a steam turbine.