Structure and Method for Indicating Undesirable Constituents In a Fuel Cell System

• US 20150194685A1
• Filed: 01/05/2015
• Published: 07/09/2015
• Est. Priority Date: 01/06/2014
• Status: Active Grant

• Current Assignee: Bloom Energy Corporation
• Original Assignee: Bloom Energy Corporation
• Inventors: Ballantine, Arne, Trevisan, David, Mahler, Jessica, Ramani, Venkat, Campbell, Emma, Wright, Michael, Schrieber, Jeffrey W.
• Granted Patent: US 9,859,580 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01N 33/52 Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper and including single- and multilayer analytical elements immunological elements G01N33/54386; involving labelled immunochemicals G01N33/58; for haemoglobin or occult blood G01N33/72
• CPC Class Codes: H01M 2008/1293 Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04201 Reactant storage and supply, e.g. means for feeding, pipes
• CPC Class Codes: H01M 8/04388 of anode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/0444 Concentration; Density H01M8/04492 takes precedence
• CPC Class Codes: H01M 8/04447 of anode reactants at the inlet or inside the fuel cell
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04686 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/04776 at auxiliary devices, e.g. reformer, compressor, burner
• CPC Class Codes: H01M 8/0662 Treatment of gaseous reactants or gaseous residues, e.g. cleaning
• CPC Class Codes: H01M 8/0675 Removal of sulfur
• CPC Class Codes: H01M 8/0687 Reactant purification by the use of membranes or filters
• CPC Class Codes: H01M 8/12 operating at high temperature, e.g. with stabilised ZrO2 electrolyte
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10T 436/18 Sulfur containing

Abstract

An optical detection system for detecting undesirable constituents in a fuel cell system includes a sensing material configured to change color in the presence of the undesirable constituents and at least one sensor configured to register the change in color of the sensing material. The sensor is coupled to a corresponding light source. The sensing material, the sensor and the light source are enclosed in a housing.

Claims

1-34. -34. (canceled)

36. (canceled)

37. (canceled)

39-43. -43. (canceled)

46-52. -52. (canceled)

54. (canceled)

58-60. -60. (canceled)

62-67. -67. (canceled)

68. A method of detecting undesirable constituents in a fuel cell system, comprising:

providing an optical detection system, wherein the optical detection system includes a sensing material configured to change color in the presence of the undesirable constituents, at least one constituent sensor configured to register the change in color of the sensing material, a reference material configured to not change color in the presence of the undesirable constituents, and a reference sensor configured to register the change in color of the reference material

detecting an undesirable constituent in a fuel stream of the fuel cell system based on a difference between a change of color of the sensing material and the reference material; and

generating an alarm signal when an alarm criterion is met.

35. The method of claim 68, wherein the optical detection system includes a processor and a plurality of sensors.

38. The method of claim 68, wherein the sensing material and the reference material each comprise paint or dye on a substrate, the sensor comprises a photodetector facing the substrate, and wherein illuminating the sensing material comprises illuminating the substrate.

44. The method of claim 35, wherein the plurality of sensors includes at least one red color sensor, at least one green color sensor, and at least one blue color sensor.

45. The method of claim 35, wherein detecting the the undesirable constituent in the fuel stream of the fuel cell system comprises detecting sulfur in an inlet fuel stream of the fuel cell system, and wherein the sensors and sensing material are positioned in a fuel inlet line or in a slipstream line of the fuel cell system.

53. The method of claim 35, wherein the alarm criterion is met when coefficients of a least squares regression of sensor values with respect to time fall outside a preset range.

55. The method of claim 35, wherein the alarm criterion is met when a first derivative, a second derivative, or a sum of absolute values of sensor values with respect to time falls outside a preset range.

56. The method of claim 35, wherein the alarm criterion is met when a sum of the absolute values of sensor values falls outside a preset range.

57. The method of claim 35, wherein detecting an undesirable constituent in a fuel stream of the fuel cell system based on a difference between a change of color of the sensing material and the reference material includes differentiating, by the processor, between a positive and negative slope of signal variation for at least one of the plurality of sensors.

61. The method of claim 35, further comprising applying, by the processor, a different alarm detection algorithm to each of the plurality of sensors, and wherein each of the plurality of sensors are positioned at different locations along a fuel inlet line of the fuel cell system.

69. The method of claim 68, wherein the at least one constituent sensor and the reference sensor are each coupled to a light source, and wherein the sensing material, the constituent sensor, the reference material, the reference sensor and the light sources are enclosed in a housing.

73. The method of claim 68, further comprising subtracting a value of a signal from the reference sensor from a value of a signal from the at least one constituent sensor to increase a signal-to-noise ratio for a signal corresponding to the change in color of the sensing material.

70-72. -72. (canceled)

74-91. -91. (canceled)

92. A fuel cell system, comprising:

a fuel cell stack;

a fuel control valve fluidly connected to the fuel cell stack;

a fuel processing module fluidly connected to the fuel cell stack and the fuel control valve; and

a detector, comprising at least one of a color change detector, an electrical resistance detector, and an artificial nose detector, wherein either the fuel control valve changes configuration or the fuel cell stack shuts off in response to the detector detecting an undesirable constituent above a threshold level in a fuel stream.

93. The fuel cell system of claim 92, further comprising an undesirable constituent database, which is used to determine at least one of an amount of undesirable constituent present in the fuel cell system or a type of undesirable constituent present in the fuel cell system.

94. The fuel cell system of claim 92, further comprising an intermediate exhaustion detector, wherein the intermediate exhaustion detector is located in the fuel processing module and detects partial exhaustion of a sorbent bed within the fuel processing module.

97. The fuel cell system of claim 92, wherein upon detecting the undesirable constituent, the fuel control valve is configured to perform at least one of selecting a different fuel source, shutting off the fuel flow to the fuel cell stack, reducing the fuel flow to the fuel cell stack, or altering the fuel flow between the sorbent beds in the fuel processing module.

95. (canceled)

96. (canceled)

98. A method of controlling fuel flow to a reserve sorbent bed in a fuel cell system, comprising:

detecting a breakthrough event in a primary sorbent bed where all or a majority of the fuel flows through the primary sorbent bed to a fuel cell stack; and

directing no fuel or a minority of fuel through the primary sorbent bed in response to detecting a breakthrough event in the primary sorbent bed.

103. The method of claim 98, further comprising:

directing at least a portion of the fuel flow through the reserve sorbent bed; and

periodically bypassing the reserve sorbent bed, the reserve sorbent bed being external to a fuel processing module and larger than the primary sorbent bed.

104. The method of claim 98, wherein:

detecting the breakthrough event comprises detecting the breakthrough event with at least one of a fuel cell stack performance monitoring system, a color change detector, a resistance change detector, and an artificial nose.

105. The method of claim 104, wherein detecting the breakthrough event comprises detecting with the fuel cell stack performance monitoring system and at least 5% decrease in fuel cell stack voltage.

113. The method of claim 98, wherein detecting the breakthrough event comprises:

calculating a flow ratio based on a ratio of a total amount of fuel flowing through the primary sorbent bed to total amount of fuel flowing through at least one sensor of the fuel cell stack, wherein the at least one sensor is capable of detecting undesirable constituents exiting the primary sorbent bed;

determining an acceptable sensor value range based on the calculated flow ratio; and

triggering an alarm if the sensor value falls outside of the acceptable range for the calculated flow ratio.

99-102. -102. (canceled)

106-112. -112. (canceled)