Energy storage power plant and method for operating such a power plant

Patent metadata

Field	Value
Publication number	US-9534508-B2
Application number	US-201314382315-A
Country	US
Kind code	B2
Filing date	Mar 12, 2013
Priority date	Mar 15, 2012
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

An energy storage power plant for harvesting electric energy, and suitable for converting electric energy into thermal energy is provided. The thermal energy can be temporarily stored in at least two thermal stores until demanded and retrieved to increase the energy content of water in a water circuit upon demand. The power plant has the at least two thermal stores, each has at least one converting device that allows electric energy to be directly or indirectly converted into thermal energy, the thermal stores being thermally chargeable by temporarily storing thermal energy, wherein one thermal store is for storing sensible heat and one thermal store is for storing latent heat; and at least one energy generating unit operated using the water in the water circuit, the energy content of the water having been increased by the temporary storage of thermal energy, in order to generate electric energy when operated.

First claim

The invention claimed is:

1. An energy storage power plant for generating electrical power which is suitable for converting electrical energy into thermal energy, wherein the thermal energy can be stored temporarily in at least two thermal storage tanks until it is needed and be retrieved when needed in order to increase an energy content of water in a water circuit, comprising:
at least two thermal storage tanks, each with at least one converting device which enables the electrical energy to be converted into the thermal energy,
wherein the at least two thermal storage tanks can be thermally charged by temporarily storing the thermal energy, and
wherein a thermal storage tank of the at least two thermal storage tanks is for storing sensible heat and a thermal storage tank of the at least two thermal storage tanks is for storing latent heat, and
wherein at least one of the at least two thermal storage tanks has a modular structure comprising modules to charge the at least one of the at least two thermal storage tanks, wherein the at least one of the at least two thermal storage tanks is thermally connected to a heat exchanger, and wherein via the heat exchanger heat can be transmitted from the modules of the at least one of the at least two thermal storage tanks to the water in the water circuit,
wherein each of the modules is provided with a respective converting device for converting the electrical energy into the thermal energy, thereby enabling each module to be charged independent of whether other modules are charging, and
at least one power generation unit configured to be operated with the water in the water circuit in order to generate electrical power during operation.

2. The energy storage power plant as claimed in claim 1 , wherein
wherein each of the modules can be discharged independent of whether other modules are discharging.

3. The energy storage power plant as claimed in claim 1 , wherein each converting device is an electric resistance heating device.

4. The energy storage power plant as claimed in claim 1 , wherein one of the at least two thermal storage tanks is configured to operate at a temperature level of less than 400° C and one of the at least two thermal storage tanks is configured to operate at a temperature level of more than 400° C.

5. The energy storage power plant as claimed in claim 1 , wherein the power generation unit comprises a high pressure steam turbine, a medium pressure steam turbine, and a low pressure steam turbine, each steam turbine being supplied by the water circuit, wherein the high pressure steam turbine is arranged to receive water comprising the heat.

6. The energy storage power plant as claimed in claim 1 , wherein at least one of the at least two thermal storage tanks is designed to evaporate water in the water circuit.

7. The energy storage power plant as claimed in claim 1 , wherein at least one of the at least two thermal storage tanks is designed to superheat water that is at least partially in the form of steam in the water circuit.

8. The energy storage power plant as claimed in claim 1 , wherein the thermal storage tank that is provided to store sensible heat is designed to be charged, discharged, or discharged and discharged at an essentially constant temperature level.

9. A method for operating an energy storage power plant as claimed in claim 1 , comprising:
operating the at least one converting device in order to convert the electrical energy into the thermal energy, the at least one of the at least two thermal storage tanks being thermally charged by temporarily storing the thermal energy, wherein the at least one of the at least two thermal storage tanks comprises the modular structure comprising the modules to charge the at least one of the thermal storage tanks, wherein the at least one of the at least two storage tanks is thermally connected to the heat exchanger, and wherein each of the modules of the at least one of the at least two thermal storage tanks is provided with the respective converting device for converting the electrical energy into the thermal energy, thereby enabling each module to be charged independent of whether other modules are charging;
transmitting the heat via the heat exchanger from the modules to the water in the water circuit;
operating the at least one power generation unit using the water in the water circuit, the energy content of which was increased by the heat in order to generate the electrical power during operation;
wherein each of the at least two thermal storage tanks is charged, discharged, or charged and discharged in a temperature-controlled fashion.

10. The method as claimed in claim 9 , further comprising receiving the electrical energy used to charge the at least one thermal storage tank from a public electricity grid.

11. A method for operating an energy storage power plant as claimed in claim 2 ,
further comprising charging or discharging one module at a different time than another module.

12. The energy storage power plant as claimed in claim 1 , wherein
each of the at least two thermal storage tanks comprises a modular structure comprising respective modules that are charged to charge a respective thermal storage tank, wherein the respective modules are chargeable independent of whether other modules are charging and dischargeable independent of whether other modules are discharging.

13. The energy storage power plant as claimed in claim 1 , wherein the power generation unit comprises at least two steam turbines each being supplied by the water circuit.

14. The energy storage power plant as claimed in claim 1 , wherein the storage tank provided to store latent heat is designed to evaporate water in the water circuit.

15. The energy storage power plant as claimed in claim 1 , wherein the storage tank provided to store sensible heat is designed to superheat water that is at least partially in the form of steam in the water circuit.

16. The energy storage power plant as claimed in claim 1 , wherein the modules are independently chargeable with differently sized quantities of thermal energy.

17. The energy storage power plant as claimed in claim 1 , wherein the modules are independently dischargeable with differently sized quantities of thermal energy.

Assignees

• Siemens Ag

Inventors

• Brunhuber Christian
• Graeber Carsten
• Zimmermann Gerhard

Classifications

• Y02E60/14

  Thermal energy storage · CPC title

• F01K23/10

  with exhaust fluid of one cycle heating the fluid in another cycle (F01K17/025 takes precedence) · CPC title

• F28D17/04

  Distributing arrangements for the heat-exchange media · CPC title

• F22B1/028

  Steam generation using heat accumulators (F22B27/14 takes precedence) · CPC title

• F28D20/02

  using latent heat · CPC title