Icing Sensor System and Method

• US 20120099616A1
• Filed: 12/16/2009
• Published: 04/26/2012
• Est. Priority Date: 12/18/2008
• Status: Active Grant

• Current Assignee: Penny & Giles Aerospace Limited
• Original Assignee: Penny & Giles Aerospace Limited
• Inventors: Penny, William, Kidd, Nicholas
• Granted Patent: US 9,156,557 B2
• Time in Patent Office: Days
• US Class Current: 374/16
• CPC Class Codes: B64D 15/20 Means for detecting icing or initiating de-icing
• CPC Class Codes: G01N 25/68 by varying the temperature of a condensing surface

Abstract

In a first aspect the invention relates to a sensor system (10) for determining a proximity to icing conditions of an environment. The system includes a sensor having a sensor surface (12) for exposure to the environment, an electrically powered heat pump means (16) for cooling and/or heating the surface (12), and a temperature detector (14) for providing a signal representative of the temperature of the surface (12). An environment temperature is determined, and a processor determines, from the temperature detected by the temperature detector (14) and the environment temperature, a proximity to icing conditions of the environment to which the surface (12) is exposed. In a second aspect of the invention the sensor system includes a power monitor for determining an amount of power required to heat or cool the surface through a temperature indicative of ice formation. The processor determines the proximity to icing conditions from the detected temperatures and the amount of cooling or heating power.

Claims

1-36. -36. (canceled)

37. An icing detection system comprising:

a sensor having a sensor surface for exposure to the environment, an electrically powered heat pump for causing heat to flow through the surface, and a first temperature detector for providing a signal representative of the temperature of the surface;

a second temperature detector for determining an environment temperature representative of the temperature of the environment to which the sensor surface is exposed; and

a processor configured to control operation of the heat pump, to monitor the temperature detected by the temperature detector and the environment temperature, to determine a temperature indicative of ice formation on the surface, and to determine the value of a difference between the environment temperature and the temperature indicative of ice formation, said value representing a proximity to icing conditions of the environment to which the surface is exposed.

38. The system of claim 37, wherein the heat pump is a bi-directional heat pump operable for cooling and heating the surface and the processor is configured to control the heat pump to cool and heat the surface, and wherein the temperature indicative of ice formation is based on one of a temperature indicative of ice on the surface melting during heating of the surface and a temperature indicative of ice forming on the surface during cooling of the surface.

39. The system of claim 37, configured for use on an aircraft so that the sensor surface lies flush with an exterior surface of the aircraft.

40. The system of claim 37 configured for use on an aircraft, wherein the sensor surface forms part of a structure mounted on an exterior surface of the aircraft.

41. The system of claim 37 configured for use on an aircraft, wherein the sensor surface has an orientation that is one of:

substantially parallel to the direction of airflow over the aircraft;

substantially perpendicular to the direction of airflow over the aircraft; and

orientated at an angle to the direction of airflow over the aircraft.

42. The system of claim 37 comprising a plurality of sensors each having a surface for exposure to the environment, wherein the processor is configured to determine the proximity to icing conditions from the detected temperatures of each of the plurality of sensors.

43. The system of claim 37 wherein the processor is configured to determine an icing severity from the monitored temperatures.

44. The system of claim 43 configured to determine the icing severity by measuring the magnitude of a change in temperature when the surface passes through the temperature indicative of ice formation .

45. The system of claim 43 configured to determine the icing severity by measuring the duration of a plateau in temperature when the surface passes through the temperature indicative of ice formation.

46. The system of claim 37 wherein the second temperature detector determines a prevailing air temperature as the environment temperature.

47. The system of claim 46 configured to determine the environment temperature from a temperature of the surface when not operating the heat pump.

48. The system of claim 37 further configured to determine an indication of a time to icing conditions arising.

49. The system of claim 37 further configured to determine an icing potential by measuring the rate and direction of change of the proximity to icing conditions.

50. The system of claim 37, wherein the temperature indicative of ice formation is determined by measuring the variation of temperature with time and detecting a change in direction in the variation of temperature with time resulting from the latent heat of ice formation.

51. The system of claim 37, wherein the processor is configured to control the heat pump to provide a substantially constant rate of change of temperature per unit time.

52. The system of claim 37, configured to alternately cool and heat the surface.

53. The system of claim 52 configured to repeat the alternating heating and cooling continuously.

54. An icing detection system comprising:

a sensor having a sensor surface for exposure to the environment, an electrically powered heat pump for causing heat to flow through the surface, and a temperature detector for providing a signal representative of the temperature of the surface;

a power monitor configured to determine an amount of power required to cause the surface to pass through a temperature indicative of ice formation; and

a processor configured to monitor the detected temperatures, to determine from the monitored temperatures and the amount of cooling power a value of a quantity of heat that causes the surface to pass through the temperature indicative of ice formation, said value representing a proximity to icing conditions of the environment to which the surface is exposed.

55. The system of claim 54, wherein the heat pump is a bi-directional heat pump operable for cooling and heating the surface, the processor is further configured to control the heat pump to cool and heat the surface, and to determine the value of the quantity of heat that causes the surface to pass through the temperature indicative of ice formation from the amount of power required to heat the surface to cause ice on the surface to melt during heating of the surface and from the amount of power required to cool the surface to cause ice to form on the surface during cooling of the surface.

56. The system of claim 54, configured for use on an aircraft so that the sensor surface lies flush with an exterior surface of the aircraft.

57. The system of claim 54 configured for use on an aircraft, wherein the sensor surface forms part of a structure mounted on an exterior surface of the aircraft.

58. The system of claim 54 configured for use on an aircraft, wherein the sensor surface has an orientation that is one of:

substantially parallel to the direction of airflow over the aircraft;

substantially perpendicular to the direction of airflow over the aircraft; and

at an angle to the direction of airflow over the aircraft.

59. The system of claim 54 comprising a plurality of sensors each having a surface for exposure to the environment, wherein the processor is configured to determine the proximity to icing conditions from the detected temperatures and the amount of power to each of the plurality of sensors.

60. The system of claim 54 wherein the processor is configured to determine an icing severity from the monitored temperatures.

61. The system of claim 54 further configured to determine an indication of a time to icing conditions arising.

62. The system of claim 54 further configured to determine an icing potential by measuring the rate and direction of change of the proximity to icing conditions.

63. The system of claim 54 configured to operate the heat pump with a substantially constant power.

64. The system of claim 54, configured to determine the temperature indicative of ice formation by measuring the variation of temperature with time and detecting a change in direction in the variation of temperature with time resulting from the latent heat of ice formation.

65. The system of claim 54, configured to operate the heat pump to provide a substantially constant rate of change of temperature per unit time.

66. The system of claim 65, configured to determine the temperature indicative of ice formation by monitoring the power with time to detect the temperature at which a change in the power occurs resulting from the latent heat of ice formation.

67. The system of claim 54, configured to alternately cool and heat the surface.

68. The system of claim 67 configured to repeat the alternating heating and cooling continuously.

69. The system of claim 54 further configured to determine a severity of icing by measuring the magnitude of a change in temperature when the surface passes through the temperature indicative of ice formation.

70. The system of claim 54 further configured to determine a severity of icing by measuring the duration of a plateau in temperature when the surface passes through the temperature indicative of ice formation.

71. An icing detection system comprising:

a rotating surface;

a sensor mounted to the rotating surface, wherein the sensor comprises temperature detector for determining a temperature of the rotating surface and a temperature of an environment through which the surface rotates; and

a processor configured to determine a proximity to icing conditions based on the detected temperatures.

72. The system of claim 71 where the sensor comprises a surface that is angled to the incident airflow.

73. The system of claim 71, wherein the rotating surface comprises a surface selected from a group of surfaces that comprises a rotor, a rotor assembly, a propeller, and a turbine vane.