Two-phase thermal management system with active control for high density electric machine

Patent metadata

Field	Value
Publication number	US-11804754-B2
Application number	US-202017126605-A
Country	US
Kind code	B2
Filing date	Dec 18, 2020
Priority date	Dec 18, 2020
Publication date	Oct 31, 2023
Grant date	Oct 31, 2023

Abstract

An electric motor system includes an electric motor, and a thermal management system. The thermal management system includes a two-phase refrigerant circuit circulating a flow of refrigerant through the electric motor, and a refrigerant-air heat exchanger fluidly connected to the electric motor via the two-phase refrigerant circuit, such that the flow of refrigerant is boiled via heat generated by the electric motor, and returned to a subcooled liquid state to cool the electric motor. A method of dissipating thermal energy from an electric motor includes urging a flow of refrigerant through an electric motor, thereby boiling the flow of refrigerant, directing the flow of refrigerant from the electric motor to a refrigerant-air heat exchanger via a two-phase refrigerant circuit, and cooling the refrigerant to a sub-cooled liquid state at the refrigerant-air heat exchanger via thermal energy exchange with a flow of air through the refrigerant-air heat exchanger.

First claim

What is claimed is:

1. An electric motor system, comprising:
an electric motor;
and
a thermal management system, comprising:
a two-phase refrigerant circuit circulating a flow of refrigerant through the electric motor; and
a refrigerant-air heat exchanger fluidly connected to the electric motor via the two-phase refrigerant circuit, such that the flow of refrigerant is boiled via heat generated by the electric motor, and returned to a subcooled liquid state to cool the electric motor;

a motor drive operably connected to the electric motor and fluidly connected to the refrigerant-air heat exchanger via the two-phase refrigerant circuit such that the flow of refrigerant cools the motor drive;
one or more sensors disposed along the two-phase refrigerant circuit to detect one or more flow conditions of the flow of refrigerant;
one or more valves configured to regulate the flow of refrigerant through the electric motor and the motor drive; and
a controller operably connected to the one or more sensors and the one or more valves, the controller configured to operate the one or more valves in response to the detected one or more flow conditions.

2. The electric motor system of claim 1 , wherein the electric motor and the motor drive are fluidly connected to the two-phase refrigerant in a parallel relationship.

3. The electric motor system of claim 1 , wherein the electric motor and the motor drive are fluidly connected to the two-phase refrigerant in a serial relationship.

4. The electric motor of claim 1 , wherein the one or more flow conditions include one or more of temperature or pressure of the flow of refrigerant.

5. The electric motor system of claim 1 , further comprising:
a gear box operably connected to the electric motor; and
a lubricant circuit circulating a flow of lubricant through the gear box; and
wherein the lubricant circuit circulates the flow of lubricant through the refrigerant-air heat exchanger, such that the flow of lubricant is cooled at the refrigerant-air heat exchanger prior to being returned to the gear box.

6. The electric motor system of claim 1 , further comprising a refrigerant reservoir disposed along the refrigerant circuit downstream of the refrigerant-air heat exchanger.

7. The electric motor system of claim 6 , further comprising a bypass passage allowing for selective bypass of the refrigerant reservoir by the flow of refrigerant.

8. The electric motor system of claim 1 , wherein the flow of refrigerant is a dielectric refrigerant.

9. A method of dissipating thermal energy from an electric motor, comprising:
urging a flow of refrigerant through an electric motor, thereby boiling the flow of refrigerant;
directing the flow of refrigerant from the electric motor to a refrigerant-air heat exchanger via a two-phase refrigerant circuit;
cooling the refrigerant to a sub-cooled liquid state at the refrigerant-air heat exchanger via thermal energy exchange with a flow of air through the refrigerant-air heat exchanger;
directing at least a portion of the flow of refrigerant through a motor drive operably connected to the electric motor and fluidly connected to the refrigerant-air heat exchanger via the two-phase refrigerant circuit such that the flow of refrigerant cools the motor drive;
detecting one or more flow conditions of the flow of refrigerant via one or more sensors disposed along the two-phase refrigerant circuit; and
operating one or more valves configured to regulate the flow of refrigerant through the electric motor and the motor drive based on the one or more flow conditions.

10. The method of claim 9 wherein the electric motor and the motor drive are fluidly connected to the two-phase refrigerant circuit in a parallel relationship.

11. The method of claim 9 , wherein the one or more flow conditions are one or more of pressure or temperature of the flow of refrigerant.

12. The method of claim 9 , further comprising:
flowing a flow of lubricant through a gear box operably connected to the electric motor;
directing the flow of lubricant from the gear box to the refrigerant-air heat exchanger via a lubricant circuit; and
cooling the lubricant at the refrigerant-air heat exchanger via thermal energy exchange with a flow of air through the refrigerant-air heat exchanger.

13. A thermal management system for an electric motor system, comprising:
a refrigerant-air heat exchanger;
a two-phase refrigerant circuit fluidly connected to the refrigerant-air heat exchanger and to an electric motor, a flow of refrigerant circulating through the refrigerant circuit to cool the electric motor;
a lubricant circuit fluidly connected to the refrigerant-air heat exchanger and to a gear box operably connected to the electric motor, a flow of lubricant circulating through the lubricant circuit cooled at the refrigerant-air heat exchanger;
one or more sensors disposed along the two-phase refrigerant circuit to detect one or more flow conditions of the flow of refrigerant;
one or more valves configured to regulate the flow of refrigerant through the electric motor and the motor drive; and
a controller operably connected to the one or more sensors and the one or more valves, the controller configured to operate the one or more valves in response to the detected one or more flow conditions.

14. The thermal management system of claim 13 , wherein the two-phase refrigerant circuit is fluidly connected to a motor drive operably connected to the electric motor, at least a portion of the flow of refrigerant directed through the motor drive to cool the motor drive.

15. The thermal management system of claim 13 , wherein the one or more flow conditions include one or more of temperature or pressure of the flow of refrigerant.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Saviers Kimberly Rae
• Alahyari Abbas A
• Sur Aritra
• Tangudu Jagadeesh Kumar

Classifications

• H02K9/20 Primary

  wherein the cooling medium vaporises within the machine casing · CPC title

• F25B43/02

  for separating lubricants from the refrigerant · CPC title

• H02K7/116

  with gears · CPC title

• H02K11/33

  Drive circuits, e.g. power electronics (H02K11/38 takes precedence) · CPC title

• H02K11/25

  Devices for sensing temperature, or actuated thereby · CPC title