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US-12620881-B2 - High temperature alternator for geothermal applications

US12620881B2US 12620881 B2US12620881 B2US 12620881B2US-12620881-B2

Abstract

Among other things, the present disclosure relates to an alternator for high temperature applications, (i.e., an alternator capable of operating at temperatures greater than approximately 250° C.). The alternator for high temperature applications may include permanent magnets arranged in a topology which may enable the alternator and connected application system to start operating without an external or auxiliary power source. When used in geothermal applications, the alternator may be capable of using drilling fluid as a coolant.

Inventors

  • Ben David MCGILTON
  • Lee Jay Fingersh

Assignees

  • ALLIANCE FOR SUSTAINABLE ENERGY, LLC

Dates

Publication Date
20260505
Application Date
20230519

Claims (11)

  1. 1 . An alternator for high temperature applications, the alternator comprising: a stator having an interior; and a rotor comprises a permanent magnet pole embedded within the rotor; wherein: the rotor is concentrically positioned within the interior of the stator, and the permanent magnet pole comprises samarium cobalt (SmCo); the alternator is configured to have a power rating of about 35 kW when the rotor has a speed of about 900 rpm and the alternator is at a temperature of about 350° C.
  2. 2 . The alternator of claim 1 , further comprising: a rotor shaft which is substantially concentric to the stator and the rotor; wherein: the shaft comprises a hole, and a fluid is configured to flow through the hole.
  3. 3 . The alternator of claim 2 , wherein: the fluid comprises a drilling fluid.
  4. 4 . The alternator of claim 3 , wherein: the drilling fluid is configured to cool the alternator.
  5. 5 . The alternator of claim 1 , wherein: the alternator is capable of operating at temperatures greater than approximately 200° C.
  6. 6 . The alternator of claim 1 , wherein: the permanent magnet pole comprises a V-type double layer formation, the V-type double layer formation comprises a first permanent magnet pole and a second permanent magnet pole meeting at an angle, and the angle comprises greater than approximately 90°.
  7. 7 . The alternator of claim 1 , wherein: the stator comprises greater than 25 slots.
  8. 8 . The alternator of claim 7 , wherein: the stator comprises 27 slots.
  9. 9 . The alternator of claim 7 , wherein: the stator has a double layer winding, and the stator has a 4 slot span.
  10. 10 . The alternator of claim 9 , wherein: the double layer winding comprises greater than 4 turns.
  11. 11 . The alternator of claim 9 , wherein: the double layer winding comprises 5 turns, and the double layer winding comprises 10 turns per slot.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to U.S. Provisional Patent Application No. 63/344,216 filed on May 20, 2022, the contents of which are incorporated herein by reference in their entirety. CONTRACTUAL ORIGIN This invention was made under a CRADA (CRD-24-30778) between GA Drilling LLC. and the National Renewable Energy Laboratory (NREL) operated for the United States Department of Energy (DOE). NREL is managed and operated under Contract No. DE-AC36-08GO28308 awarded by the DOE. The United States government has certain rights in this invention. BACKGROUND The potential for geothermal energy generation is significantly limited by the speed and cost of drilling geothermal wells through hard rock formations. Drilling rates for geothermal energy in the United States average approximately 125 feet per day, more than almost 40 times slower than drilling rates through softer rocks in the oil and gas industry. As the rock formations drilled through are different for the two industries, traditional drilling methods and devices used in the oil and gas industry cannot easily be utilized in geothermal energy. To access hotter geothermal energy sources, drilling system components need to withstand temperatures greater than approximately 250° C. Thus, there exists a need for a drilling system which can operate at these high temperatures and effectively drill geothermal energy wells through hard rock formations. SUMMARY Among other things, the present disclosure relates to an alternator for high temperature applications, that is, an alternator capable of operating at temperatures greater than approximately 250° C. The alternator for high temperature applications may include permanent magnet poles arranged in a topology which may enable the alternator for high temperature applications and connected application system to start without an external or auxiliary power source. When used in geothermal drilling applications, the alternator for high temperature applications may be capable of using drilling fluid as a coolant. This is because in geothermal drilling applications, the drilling fluid may be slightly cooler (i.e., approximately 50° C. less than) the alternator for high temperature applications. An aspect of the present disclosure is an alternator for high temperature applications, the alternator including a stator having an interior, and a rotor includes a permanent magnet pole embedded within the rotor in which the rotor is concentrically positioned within the interior of the stator, the permanent magnet is made of samarium cobalt (SmCo). In some embodiments, the alternator also includes rotor shaft which is substantially concentric to the stator and the rotor, the shaft comprises a hole, and a fluid is configured to flow through the hole. In some embodiments, the fluid is a drilling fluid which may be used to cool the alternator. In some embodiments, the alternator may be capable of operating at temperatures greater than approximately 200° C. In some embodiments, the permanent magnet pole comprises a V-type double layer formation which includes a first permanent magnet pole and a second permanent magnet pole meeting at an angle, and the angle is greater than approximately 90°. In some embodiments, the stator includes more than 25 slots. In some embodiments, the stator has 27 slots. In some embodiments, the stator has a double layer winding, and has a 4-slot span. In some embodiments, the double layer winding has greater than 4 turns. In some embodiments, the double layer winding makes 5 turns, and the double layer winding has 10 turns per slot. In some embodiments, the alternator can generate at least 35 kW of power. In some embodiments, the rotor can be operated at a speed in the range of about 500 rpm to about 2000 rpm. In some embodiments, the rotor can be operated at a speed of approximately 900 rpm. In some embodiments, the rotor can be operated at a speed of approximately 1200 rpm. BRIEF DESCRIPTION OF THE DRAWINGS Exemplary embodiments are illustrated in the referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are considered to be illustrative rather than limiting. FIG. 1 illustrates a top view of an exemplary alternator for high temperature applications, according to some aspects of the present disclosure. FIG. 2 illustrates a coil winding layout for an exemplary alternator for high temperature applications, according to some aspects of the present disclosure. FIG. 3 illustrates the mechanical power and electrical power at operating conditions of approximately 900 rpm and approximately 350° C. for an exemplary alternator for high temperature applications, according to some aspects of the present disclosure. FIG. 4 illustrates the mechanical torque for approximately 35 kW power output at operating conditions of approximately 900 rpm and approximately 350° C. for an exemplary alternator for high temperature applications, accord