OIL LEVEL DETECTING APPARATUS AND CONTROL METHOD THEREOF, OIL FLOW DETECTING APPARATUS AND CONTROL METHOD THEREOF, METHOD FOR CONTROL OIL RETURN USING OIL LEVEL AND OIL FLOW

• US 20160187173A1
• Filed: 08/19/2015
• Published: 06/30/2016
• Est. Priority Date: 12/30/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: JANG, Yong Hee, Koo, Hyung Mo, Cho, II Yong, Choi, Byung Ik, Lee, Hyo Sang, Lee, Suk Ho, Lim, Byoung Guk, Han, Jeong Su
• Granted Patent: US 10,025,323 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F01M 11/12 concerning lubricant level
• CPC Class Codes: F04B 2201/0404 Lubricating oil condition
• CPC Class Codes: F04B 39/023 Hermetic compressors
• CPC Class Codes: F04B 51/00 Testing machines, pumps, or pumping installations
• CPC Class Codes: F04C 18/0215 where only one member is moving
• CPC Class Codes: F04C 2240/809 Lubricant sump
• CPC Class Codes: F04C 2240/81 Sensor, e.g. electronic sensor for control or monitoring
• CPC Class Codes: F04C 23/008 Hermetic pumps
• CPC Class Codes: F04C 29/02 Lubrication of machines or engines in general F01M; Lubricant separation separation in general B01D
• CPC Class Codes: G01F 1/6847 where sensing or heating elements are not disturbing the fluid flow, e.g. elements mounted outside the flow duct
• CPC Class Codes: G01F 23/0007 for discrete indicating and measuring G01F23/02 - G01F23/28 take precedence
• CPC Class Codes: G01F 23/265 for discrete levels
• CPC Class Codes: G01F 23/266 measuring circuits therefor
• CPC Class Codes: G01F 23/268 mounting arrangements of probes
• CPC Class Codes: G05D 7/0635 by action on throttling means G05D7/0688, G05D7/0694 take precedence
• CPC Class Codes: G05D 9/12 characterised by the use of electric means
• CPC Class Codes: Y10T 137/7306 Electrical characteristic sensing

Abstract

An apparatus for detecting an oil level and a method for controlling the same, an apparatus for detecting oil flow and a method for controlling the same, and a method for controlling oil return using the detected oil level and the detected oil flow are disclosed. The level of oil stored in a compressor is measured at two or more positions. The frequency comparison scheme using two electrodes can correctly detect the level of oil stored in the compressor, a refrigerant state, and the level of mixed oils, and can determine an internal state of the compressor and a normal or abnormal state of the oil return system, such that the oil return control can be actively controlled. The flow of oil in the oil return pipe is detected so as to determine whether the oil is normally supplied in real time, such that a malfunction of the compressor is prevented and a valve state can be checked. The level of oil stored in the compressor is adjusted not only using the oil level detection result but also the oil flow detection result, and the oil return operation can be controlled.

Claims

1. An oil level detection apparatus comprising:

an oil level sensor installed in a compressor to measure a capacitance value that changes according to a level of oil contained in the compressor at a plurality of positions;

a signal processor configured to convert a plurality of capacitance values measured by the oil level sensor into frequency signals; and

a controller configured to determine the level of oil on the basis of the frequency signals received from the signal processor.

2. The oil level detection apparatus according to claim 1, wherein the oil level sensor is installed at an oil storage portion provided below the compressor, and comprises first and second detection portions vertically spaced apart from each other by a predetermined distance within the oil storage portion.

3. The oil level detection apparatus according to claim 2, wherein the first detection portion comprises a first reference electrode and a first detection electrode arranged at both sides of the first reference electrode, and wherein the first detection portion determines whether the level of oil is equal to or higher than a first reference level.

4. The oil level detection apparatus according to claim 3, wherein the first detection electrode comprises:

a first base portion spaced apart from one side of the first reference electrode by a first predetermined distance; and

a first augmentation portion spaced apart from another side of the first reference electrode by a second predetermined distance.

5. The oil level detection apparatus according to claim 4, wherein the first detection portion outputs a value corresponding to a capacitance between the first reference electrode and the first base portion and a value corresponding to a capacitance between the first reference electrode and the first augmentation portion.

6. The oil level detection apparatus according to claim 2, wherein the second detection portion includes a second reference electrode spaced apart from the first reference electrode by a predetermined distance and a second detection electrode disposed respectively at each side of the second reference electrode, and wherein the second detection portion determines whether the level of oil is between the first reference level and the second reference level or is less than the second reference level.

7. The oil level detection apparatus according to claim 6, wherein the second detection electrode comprises:

a second base portion spaced apart from one side of the second reference electrode by a third predetermined distance; and

a second augmentation portion spaced apart from the other side of the second reference electrode by a fourth predetermined distance.

8. The oil level detection apparatus according to claim 7, wherein the second detection portion outputs a value corresponding to a capacitance between the second reference electrode and the second base portion and a value corresponding to a capacitance between the second reference electrode and the second augmentation portion.

9. The oil level detection apparatus according to claim 2, wherein the signal processor converts voltage signals corresponding to a plurality of capacitance values measured by the oil level sensor into trigger frequency signals, and outputs the trigger frequency signals.

10. The oil level detection apparatus according to claim 9, wherein the controller compares a difference among a plurality of sensor output values generated by the oil level sensor with a reference value, and determines the level of oil according to the result of comparison.

11. The oil level detection apparatus according to claim 10, wherein the reference value is established to determine whether the level of oil contacting the oil level sensor is in any one of a normal range, an excessive range, or an insufficient range.

12. The oil level detection apparatus according to claim 11, wherein the reference value includes:

a first reference value for determining whether the level of oil is between the first detection portion and the second detection portion; and

a second reference value for determining whether the level of oil is higher than the first detection portion.

13. The oil level detection apparatus according to claim 12, wherein the controller determines the level of oil using the first reference value and the second reference value.

14. The oil level detection apparatus according to claim 13, wherein the controller determines that the level of oil is in the normal range when a difference among the sensor output values generated from the oil level sensor is higher than the first reference value.

15. The oil level detection apparatus according to claim 13, wherein the controller determines that the level of oil is in the excessive range when a difference among the sensor output values generated from the oil level sensor is less than the second reference value.

16. The oil level detection apparatus according to claim 13, wherein the controller determines that the level of oil is in the insufficient range when a difference among the sensor output values generated from the oil level sensor is between the first reference value and the second reference value.

17. The oil level detection apparatus according to claim 9, wherein the controller compares the difference among the plurality of sensor output values generated from the oil level sensor with the reference value, and determines a state of the oil according to the result of comparison.

18. The oil level detection apparatus according to claim 17, wherein the reference value is established to determine whether a state of the oil contacting the oil level sensor is a liquid refrigerant, a bubble refrigerant, or a gaseous refrigerant.

19. An oil level detection control method comprising:

measuring a capacitance value that changes according to a level of oil contained in a compressor at a plurality of positions;

converting the plurality of measured capacitance values into frequency signals; and

determining the level of oil using output values of the converted frequency signals and using a reference value.

20. The oil level detection control method according to claim 19, wherein the reference value is established to determine whether the level of oil stored in the compressor is in any one of a normal range, an excessive range, or an insufficient range.

21. The oil level detection control method according to claim 20, wherein the reference value includes:

a first reference value for determining whether the level of oil is in a normal range; and

a second reference value for determining whether the level of oil is in the excessive range.

22. An oil flow detection apparatus comprising:

a heating unit installed in a pipe through which oil of an accumulator returns to a compressor, configured to heat the pipe;

a temperature measurement unit configured to measure a pipe temperature changed according to the flow of oil existing in the pipe; and

a controller configured to monitor a variation of the pipe temperature measured by the temperature measurement unit and to monitor a flow of oil through the pipe on the basis of the monitored variation of the pipe temperature.

23. The oil flow detection apparatus according to claim 22, further comprising:

a valve controlled to allow the oil to return to the compressor,

wherein the temperature measurement unit measures a pipe surface temperature changed according to the flow of oil existing in the pipe.

24. The oil flow detection apparatus according to claim 23, wherein the controller compares a pipe temperature variation measured when the valve is switched on or off during heating with a reference temperature, and determines a presence or absence of the flow of oil through the pipe according to the result of the comparison.

25. The oil flow detection apparatus according to claim 24, wherein the controller determines the presence of the flow of oil when the pipe temperature variation is less than the reference temperature.

26. The oil flow detection apparatus according to claim 23, wherein the controller, when the flow of oil is absent, switches the valve on or off so as to determine a presence or absence of a malfunction of the valve.

27. The oil flow detection apparatus according to claim 26, wherein the controller compares a pipe temperature variation measured when the valve is switched on or off with a reference temperature, and determines the presence or absence of the malfunction of the valve according to the result of comparison.

28. The oil flow detection apparatus according to claim 27, wherein the controller, if the pipe temperature variation measured when the valve is switched off is higher than the reference temperature during heating, determines that the valve is in a normal state.

29. The oil flow detection apparatus according to claim 27, wherein the controller, if the pipe temperature variation measured when the valve is switched off during heating, determines that the valve is in a malfunction state.

30. An oil flow detection control method comprising:

heating a pipe through which oil of an accumulator returns to a compressor;

measuring a pipe temperature change according to a flow of oil in the pipe; and

comparing the measured pipe temperature with a reference temperature, and determining a presence or absence of the flow of oil according to a result of comparison.

31. The oil flow detection control method according to claim 30, further comprising:

switching a valve on to return the oil to the compressor,

wherein the measuring of the pipe temperature includes measuring a pipe surface temperature changed according to the flow of oil existing in the pipe when the valve is switched on.

32. The oil flow detection control method according to claim 31, wherein the determining of the presence or absence of the flow of oil includes:

if the pipe temperature variation measured when the valve is switched on during heating is less than the reference temperature, determining that the oil flows into the pipe.

33. The oil flow detection control method according to claim 30, further comprising:

switching the valve off so as to determine the presence or absence of a malfunction of the valve,

wherein the measuring of the pipe temperature includes;

measuring a pipe surface temperature changed when the valve is switched off.

34. The oil flow detection control method according to claim 33, wherein the determining of the presence or absence of the malfunction of the valve includes:

if the pipe temperature variation measured when the valve is switched off is less than the reference temperature, determining the presence of the malfunction of the valve.

35. An oil return operation control method comprising:

detecting a level of oil stored in a compressor;

controlling a valve, installed in a pipe through which the oil of an accumulator returns, to return the oil if the detected level of oil stored in the compressor is at an insufficient level;

detecting whether the oil flows into the pipe through the controlling of the valve;

if the flow of oil into the pipe is not detected, repeating the controlling of the valve to return the oil a predetermined number of times; and

if the quantity of the repeated operations of controlling of the valve to return the oil is higher than the predetermined number of times, entering an operation to return the oil when the level of oil is the insufficient level.

36. The oil return operation control method according to claim 35, further comprising:

if the level of oil is the insufficient level, checking a state of the valve, and controlling the valve in such a manner that the returning of the oil is achieved according to the state of the valve.

37. The oil return operation control method according to claim 35, further comprising:

if the flow of oil is not detected when the valve is switched off, switching the valve on in such a manner that returning of the oil is performed.

38. The oil return operation control method according to claim 35, further comprising:

after completion of the operation to return the oil, detecting the level of oil stored in the compressor; and

if the level of oil is the insufficient level, outputting a signal for checking a system.

39. An oil level sensor comprising:

a first detection electrode comprising a first reference portion, a first base portion, and a first augmentation portion, wherein the first base portion and the first augmentation portion are respectively disposed at each side of the first reference portion; and

a second detection electrode comprising a second reference portion, a second base portion, and a second augmentation portion, wherein the second base portion and the second augmentation portion are respectively disposed at each side of the second reference portion,

wherein the second detection electrode is spaced apart from the first detection electrode by a predetermined vertical distance.

40. The oil level sensor of claim 39 wherein the first base portion and the first augmentation portion are interconnected by a first connection member.

41. The oil level sensor of claim 39 wherein the first base portion and the first augmentation portion are each configured in the form of a plate, a size of the first base portion is identical to a size of the first augmentation portion, and neither of the first base portion or the first augmentation portion is parallel to the reference portion or to each other.

42. The oil level sensor of claim 39 wherein the first detection electrode comprises a flow portion formed at a bottom surface of the first reference portion in a right triangle plate shape.

43. The oil level sensor of claim 39 wherein the first detection electrode comprises a flow portion formed at a bottom surface of the first reference portion in an isosceles triangle plate shape.

44. The oil level sensor of claim 39 wherein the first detection electrode comprises a flow portion formed at a bottom surface of the first reference portion in a serrated plate shape in which a plurality of triangular plates are linearly arranged.

45. The oil level sensor of claim 39 wherein the first detection electrode comprises a flow portion formed in a triangular plate shape at a bottom surface of any of the first reference portion, the first base portion, and the first augmentation portion.

46. An oil level sensing apparatus configured to be disposed in an oil storage portion of a compressor of an air conditioning unit, the apparatus comprising:

a first detection portion comprising a first electrode disposed in the oil storage portion;

a second detection portion comprising a second electrode disposed in the oil storage portion, the second detection portion being spaced apart from the first detection portion by a predetermined vertical distance; and

a connection portion to electrically interconnect the first detection portion and the second detection portion.