Circulation pump, heating system and method of determining the flow rate of a liquid through a pipe

• US 20090121034A1
• Filed: 10/30/2008
• Published: 05/14/2009
• Est. Priority Date: 11/05/2007
• Status: Active Grant

• Current Assignee: ITT Manufacturing Enterprises, Inc. (ITT, Inc.)
• Original Assignee: Birger Laing, Karsten Laing, Oliver Laing
• Inventors: Laing, Karsten, Laing, Oliver
• Granted Patent: US 8,714,934 B2
• Time in Patent Office: Days
• US Class Current: 237/2.A
• CPC Class Codes: F04D 13/06 the pump being electrically driven
• CPC Class Codes: F04D 13/0633 Details of the bearings
• CPC Class Codes: F04D 15/0088 Testing machines
• CPC Class Codes: F04D 29/0467 Spherical bearings
• CPC Class Codes: G01F 1/206 Measuring pressure, force or momentum of a fluid flow which is forced to change its direction
• CPC Class Codes: G01F 11/22 for liquid or semiliquid
• CPC Class Codes: G01F 25/10 of flowmeters

Abstract

In order to provide a circulation pump for a conveyed liquid, comprising an electric motor, which is electronically commutated and has a rotor, a stator and a motor circuit, and an impeller that is connected in a rotationally fixed manner to the rotor, with advantageous properties, it is provided that the electric motor has an evaluation device, by means of which a flow rate of conveyed liquid through the circulation pump can be determined from a rotational speed of the rotor and/or a power consumption of the electric motor, and at least one signal output is provided, at which a flow rate signal and/or flow rate-dependent switching signal can be supplied by the circulation pump.

Claims

1. Circulation pump for a conveyed liquid, comprising:

an electric motor, which is electronically commutated and has a rotor, a stator and a motor circuit; and

an impeller that is connected in a rotationally fixed manner to the rotor;

wherein the electric motor has an evaluation device, by means of which a flow rate of conveyed liquid through the circulation pump is determinable from at least one of a rotational speed of the rotor and a power consumption of the electric motor, and at least one signal output is provided, at which at least one of a flow rate signal and flow rate-dependent switching signal is suppliable by the circulation pump.

2. Circulation pump according to claim 1, wherein the evaluation device is at least partially integrated into the motor circuit.

3. Circulation pump according to claim 1, wherein the evaluation device comprises at least one processor, which is a processor of the motor circuit.

4. Circulation pump according to claim 1, wherein the evaluation device comprises a storage device.

5. Circulation pump according to claim 4, wherein in the storage device a characteristic or a family of characteristics and/or an algorithm relating to the dependence of the flow rate upon the rotational speed of the rotor given a constant motor power and/or the dependence of the flow rate upon the motor power given a constant rotational speed of the rotor are stored.

6. Circulation pump according to claim 1, wherein the electric motor has an operating mode with control to a constant motor power.

7. Circulation pump according to claim 6, wherein the constant motor power is adjustable.

8. Circulation pump according to claim 1, wherein the electric motor has an operating mode with control to a constant rotational speed.

9. Circulation pump according to claim 8, wherein the constant rotational speed is adjustable.

10. Circulation pump according to claim 1, wherein an operating mode is provided in which the evaluation device supplies a flow rate-dependent switching signal with an adjusted or adjustable hysteresis.

11. Circulation pump according to claim 1, wherein the motor circuit is disposed in a second chamber of a housing, which second chamber is separate from a first chamber of the housing, in which first chamber the stator and the rotor are disposed.

12. Circulation pump according to claim 11, wherein the evaluation device is disposed in the second chamber.

13. Electric motor according to claim 1, wherein the rotor is of a spherical design facing the stator.

14. Electric motor according to claim 1, wherein the rotor is spherically mounted.

15. Electric motor according to claim 1, wherein there is associated with the stator an interface that faces the rotor and is of spherical design.

16. Electric motor according to claim 1, wherein the rotor by means of one or more permanent magnets is a magnetic-field-generating rotor.

17. Electric motor according to claim 1, wherein coils of the stator are disposed below the rotor.

18. Electric motor according to claim 1, characterized by at least one temperature sensor that is associated with the stator for measuring the temperature at at least one coil of the stator.

19. Electric motor according to claim 18, wherein the at least one temperature sensor is connected in a signal-effective manner to the evaluation device.

20. Electric motor according to claim 19, wherein the evaluating device comprises a program unit that takes the resistance of stator coils into account when determining the flow rate.

21. Electric motor according to claim 1, wherein the evaluation device comprises a program unit that takes a bearing friction during the rotation of the rotor into account when determining the flow rate.

22. Heating system for heating a liquid in a basin, comprising:

a flow-through region for liquid that is positioned outside a liquid receiving space of the basin;

a heater that is disposed at the flow-through region;

a control device for the heater; and

a circulation pump for conveying the liquid through the flow-through region, wherein at least one signal output of the circulation pump is connected in a signal-effective manner to the control device;

said circulation pump comprising;

an electric motor, which is electronically commutated and has a rotor, a stator and a motor circuit; and

an impeller that is connected in a rotationally fixed manner to the rotor;

wherein the electric motor has an evaluation device, by means of which a flow rate of conveyed liquid through the circulation pump is determinable from at least one of a rotational speed of the rotor and a power consumption of the electric motor, and at least one signal output is provided, at which at least one of a flow rate signal and flow rate-dependent switching signal is suppliable by the circulation pump.

23. Method of determining the flow rate of a liquid through a pipe, comprising:

conveying the liquid by means of a circulation pump, which has an electronically commutated electric motor;

determining the flow rate by means of an evaluation device, which is integrated into the circulation pump, from at least one of the rotational speed of a rotor of the electric motor and from the motor power; and

supplying at least one of a flow rate signal and flow rate-dependent switching signal by the circulation pump.

24. Method according to claim 23, wherein the evaluation device determines the flow rate from at least one of a stored characteristic, a stored family of characteristics, and an algorithm.

25. Method according to claim 23, wherein the circulation pump during operation is controlled to a constant motor power or to a constant rotational speed.

26. Method according to claim 23, wherein at least one of the flow rate signal and switching signal is supplied to a control device of a heater, which is disposed on the pipe.

27. Method according to claim 23, wherein the circulation pump supplies a flow rate-dependent switching signal with a predetermined hysteresis.