Thermal energy storage system with high efficiency heater control

Patent metadata

Field	Value
Publication number	US-12595973-B2
Application number	US-202519218096-A
Country	US
Kind code	B2
Filing date	May 23, 2025
Priority date	May 24, 2024
Publication date	Apr 7, 2026
Grant date	Apr 7, 2026

Abstract

A thermal energy storage (TES) system converts variable renewable electricity (VRE) to continuous heat at over 900° C. Intermittent electrical energy heats a solid medium. Heat from the solid medium is delivered continuously on demand. Heat delivery via flowing gas establishes a thermocline which maintains high outlet temperature throughout discharge. The delivered heat which may be used for processes including power generation and cogeneration. The TES system is configured to include control system components that reduce thermal losses associated with component inefficiency.

First claim

What is claimed is:

1 . A method of operating a thermal energy storage (TES) system using a thyristor and multiple of electrical heater circuits, the method including:
(a) setting the thyristor to zero conduction; (b) closing a first switch to connect an output of the thyristor to a first set of heater circuits for the TES system; (c) ramping the thyristor from zero to full conduction; (d) closing a second switch to connect the first set of heater circuits to a an electrical input; (e) opening the first switch to disconnect the thyristor from the first set of heater circuits; and (f) ramping the thyristor back to zero conduction; wherein switching operations in steps (b), (d) and (e) are performed under substantially zero load conditions.

2 . The method of claim 1 , further including repeating steps (a) through (f) to sequentially engage additional sets of heater circuits in response to available power or desired thermal distribution.

3 . The method of claim 1 , wherein each heater circuit is a three-phase circuit configured to transfer electrical energy to a thermal storage medium of the TES system.

4 . The method of claim 1 , wherein the first and second switches are mechanical switches rated for no-load switching duty.

5 . The method of claim 1 , further including:
disconnecting a second set of heater circuits from the electrical input by reversing a thyristor transfer sequence; redistributing heating within the TES system without switching under load.

6 . A thermal energy storage (TES) system configured for no-load switching operation, including:
multiple of heater circuits, each configured to convert electrical energy into heat for storage in thermal storage media; a thyristor configured to be ramped from zero to full conduction and back to zero; a first switch configured to connect an output of the thyristor to a first set of the heater circuits; a second switch configured to connect the first set of heater circuits to an electrical input; and a controller configured to:
(i) set the thyristor to zero conduction;
(ii) close the first switch to route thyristor output to the first set of heater circuits;
(iii) ramp the thyristor to full conduction;
(iv) close the second switch while the thyristor is fully conducting to connect the first set of heater circuits to the electrical input;
(v) open the first switch; and
(vi) ramp the thyristor back to zero conduction,
wherein switching operations in steps (b), (d) and (e) are performed under substantially zero load conditions.

7 . A thermal energy storage (TES) system configured for no-load switching operation, including:
multiple of heater circuits, each configured to convert electrical energy into heat for storage in thermal storage media; a thyristor configured to be ramped from zero to full conduction and back to zero; a first switch configured to connect an output of the thyristor to a first set of the heater circuits; a second switch configured to connect the first set of heater circuits to an electrical input; and a controller configured to: (i) set the thyristor to zero conduction; (ii) close the first switch to route thyristor output to the first set of heater circuits; (iii) ramp the thyristor to full conduction; (iv) close the second switch while the thyristor is fully conducting to connect the first set of heater circuits to the electrical input; (v) open the first switch; and (vi) ramp the thyristor back to zero conduction, wherein switching operations in steps (b), (d) and (e) are performed under substantially zero load conditions; wherein the controller is further configured to repeat the switching and ramping operations to sequentially engage additional sets of heater circuits based on available power or desired thermal distribution.

8 . The system of claim 6 , wherein each heater circuit is a three-phase, 300-ampere circuit configured to heat an associated thermal storage block.

9 . The system of claim 6 , wherein the first and second switches are mechanical switches rated for no-load switching duty.

Assignees

• Rondo Energy Inc

Inventors

• Von Behrens Peter Emery
• Whitney John

Classifications

• H05B1/023

  Industrial applications · CPC title

• F28D2020/0069

  Distributing arrangements; Fluid deflecting means · CPC title

• H02J2105/50

  for selectively controlling the operation of the loads · CPC title

• H02J2101/20

  Dispersed power generation using renewable energy sources · CPC title

• F28D20/025

  the latent heat storage material being in direct contact with a heat-exchange medium or with another heat storage material (F28D20/003 takes precedence) · CPC title