Electrical energy storage and discharge system

Patent metadata

Field	Value
Publication number	US-9951979-B2
Application number	US-201615012155-A
Country	US
Kind code	B2
Filing date	Feb 1, 2016
Priority date	Feb 4, 2015
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

Electrical energy storage and discharge system for storing electrical energy as thermal energy includes a heat pump cycle with first working fluid, a water steam cycle with second working fluid, a first thermal storage system with first thermal fluid, a second thermal storage system with second thermal fluid, an electrical heater member and a power regulating member, fluidly connected to each other. The system includes fluidly connected first cold and hot storage tanks, and the system includes fluidly connected second cold and hot storage tanks. The electrical heater is operably connected to the system between the tanks. The power regulating member is electrically connected to one or more electrical sources to regulate excess electrical energy, partially, to the electrical heater, and partially, to the heat pump cycle.

First claim

What is claimed is:

1. An electrical energy storage and discharge system for storing electrical energy as thermal energy, comprising:
a heat pump cycle having a first working fluid;
a water steam cycle having a second working fluid;
a first thermal storage system having a first thermal fluid, and fluidly connected to the heat pump cycle and the water steam cycle, the first thermal storage system, with the first thermal fluid, comprising,
a first cold storage tank, and
a first hot storage tank fluidly connected to the first cold storage tank;

a second thermal storage system having a second thermal fluid, and fluidly connected to the heat pump cycle and the water steam cycle, the second thermal fluid, comprising,
a second cold storage tank, and
a second hot storage tank fluidly connected to the second cold storage tank;

an electrical heater member operably connected to the first thermal storage system between the first and second storage tanks; and
a power regulating member electrically connected to one or more electrical sources to regulate excess electrical energy of the electrical sources to supply the excess electrical energy, partially, to the electrical heater member , and partially, to the heat pump cycle to enable storage of the excess electrical energy as thermal energy in the first thermal fluid.

2. The electrical energy storage and discharge system of claim 1 , wherein the heat pump cycle comprises:
a compressor for compressing the first working fluid;
a heat exchanger downstream of the compressor; and
an evaporator/heater fluidly connected to the heat exchanger,
wherein the heat pump cycle is fluidly connected to the first thermal storage system via a first fluid line passing through the heat exchanger to supply heat of the first working fluid to the first thermal fluid coming from the first cold storage tank to reach a moderate temperature value and supply to the electrical heating source located downstream of the heat exchanger, and
wherein the heat pump cycle is fluidly connected to the second thermal storage system via a third fluid line passing through the evaporator/heater, to receive heat from the second thermal fluid coming from the second hot storage tank.

3. The electrical energy storage and discharge system of claim 1 , wherein the water steam cycle comprises:
a steam turbine for expanding steam;
a condenser downstream of the steam turbine;
a first water heater downstream of the condenser; and
a boiler downstream of the first water heater for converting water of the cycle into steam,
wherein the water steam cycle is fluidly connected to the first thermal storage system via a second fluid line passing through the boiler to supply heat of the first thermal fluid to the water steam cycle, and,
wherein the water steam cycle is fluidly connected to the second thermal storage at least via a fourth fluid line passing through to the first water heater or via a fifth fluid line passing through the condenser, to heat the second thermal fluid coming from the second cold storage tank.

4. The electrical energy storage and discharge system of claim 3 , wherein the steam turbine is a multi-stage steam turbine with an extraction line configured and arranged to extract steam from the steam turbine from an intermediate stage wherein the extraction line is connected to a second water heater located in the water steam cycle downstream of the first water heater so as enable further heating of water in the water steam cycle with extraction steam.

5. The electrical energy storage and discharge system of claim 1 , wherein the power regulating member is an algorithm based power regulating member automated to utilise excess of the electrical energy for the electrical sources including at least one of solar power generating systems, wind power generating systems, grids, and the like.

6. The electrical energy storage and discharge system of claim 1 , wherein the thermal storage system, comprises a third storage tank disposed between the first and second hot storage tank, at upstream of the electrical heater member and downstream of the heat exchanger to store moderately heated the first thermal fluid in the third storage tank.

7. The electrical energy storage and discharge system of claim 1 , wherein the heat pump cycle is a transcritical heat pump cycle.

8. The electrical energy storage and discharge system of claim 1 , wherein the heat pump cycle is a supercritical heat pump cycle wherein the working fluid is in a supercritical state throughout the cycle.

9. The electrical energy storage and discharge system of claim 1 , wherein the first thermal fluid is molten salt.

10. The electrical energy storage and discharge system of claim 1 , wherein the second thermal fluid is one of water, pressured water, oil, synthetic oil and mineral oil.

Assignees

• Alstom Technology Ltd
• General Electric Technology Gmbh

Inventors

• Aga Vipluv
• Conte Enrico

Classifications

• F25B17/10 Primary

  using the endothermic solution of salt · CPC title

• F24H7/002

  using electrical energy supply · CPC title

• F22B1/16

  the heat carrier being hot liquid or hot vapour, e.g. waste liquid, waste vapour · CPC title

• F01K23/04

  condensation heat from one cycle heating the fluid in another cycle · CPC title

• F01K17/04

  for specific purposes other than heating (F01K17/06 takes precedence) · CPC title