Flow sensor and system incorporating the same for monitoring steam turbine drain valves
First Claim
1. A monitoring system for monitoring at least one drain valve disposed in a fluid conduit having a temperature affected by the presence of fluid flow, and producing a diagnosis of the condition of each drain valve as functional, clogged or stuck shut, stuck open, or cold fluid flow through the drain valve, comprising:
- at least one flow sensor, each flow sensor including a heater attached to an exterior surface of the fluid conduit downstream of the drain valve, the heater, when energized, producing a thermal gradient along the fluid conduit which varies as a function of fluid flow, a first temperature sensing element attached to the exterior surface of the fluid conduit at a position spaced downstream of the heater and producing an output indicative of the temperature of the fluid conduit at the position of the first temperature sensing element, a second temperature sensing element attached to the exterior surface of the fluid conduit at a position spaced downstream of the first temperature sensing element, and producing an output indicative of the temperature of the fluid conduit at the position of the second temperature sensing element, and means responsive to the outputs of the first and second temperature sensing elements for producing a differential temperature output signal based on a difference between the temperature sensed at the first temperature sensing element and the temperature sensed at the second temperature sensing element, the differential temperature output signal having relatively greater and lesser values responsive to and thereby indicative of the presence and absence of fluid flow,drain valve position indicator means for producing and outputting a signal indicative of a selected position for each corresponding drain valve,operating condition indicator means for producing and outputting a signal indicative of an operating condition of the steam turbine, andcontrol means responsive to the output signals of the operating condition indicator means, the differential temperature producing means, and the drain valve position indicator means, for outputting a signal indicative of a diagnosis of the drain valve, anddisplay means, responsive to the output signal of the control means, for displaying the diagnosis of the drain valve.
1 Assignment
0 Petitions
Accused Products
Abstract
A flow sensor includes a strap-on heater attached to a fluid conduit downstream of a drain valve and two differential temperature measuring thermocouples attached to the fluid conduit downstream of the heater. A monitoring system employing at least one of the flow sensors further includes a controller which receives the differential temperature signal produced by the two thermocouples, a signal indicative of a selected valve position, and a signal indicative of steam turbine operating condition, i.e., hot or cold. The controller includes a logic circuit for correlating the differential temperature value signal, the valve position signal and the steam turbine condition signal to a diagnosis of the drain valve condition.
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Citations
17 Claims
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1. A monitoring system for monitoring at least one drain valve disposed in a fluid conduit having a temperature affected by the presence of fluid flow, and producing a diagnosis of the condition of each drain valve as functional, clogged or stuck shut, stuck open, or cold fluid flow through the drain valve, comprising:
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at least one flow sensor, each flow sensor including a heater attached to an exterior surface of the fluid conduit downstream of the drain valve, the heater, when energized, producing a thermal gradient along the fluid conduit which varies as a function of fluid flow, a first temperature sensing element attached to the exterior surface of the fluid conduit at a position spaced downstream of the heater and producing an output indicative of the temperature of the fluid conduit at the position of the first temperature sensing element, a second temperature sensing element attached to the exterior surface of the fluid conduit at a position spaced downstream of the first temperature sensing element, and producing an output indicative of the temperature of the fluid conduit at the position of the second temperature sensing element, and means responsive to the outputs of the first and second temperature sensing elements for producing a differential temperature output signal based on a difference between the temperature sensed at the first temperature sensing element and the temperature sensed at the second temperature sensing element, the differential temperature output signal having relatively greater and lesser values responsive to and thereby indicative of the presence and absence of fluid flow, drain valve position indicator means for producing and outputting a signal indicative of a selected position for each corresponding drain valve, operating condition indicator means for producing and outputting a signal indicative of an operating condition of the steam turbine, and control means responsive to the output signals of the operating condition indicator means, the differential temperature producing means, and the drain valve position indicator means, for outputting a signal indicative of a diagnosis of the drain valve, and display means, responsive to the output signal of the control means, for displaying the diagnosis of the drain valve. - View Dependent Claims (2, 3, 4)
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5. A monitoring system for monitoring at least one drain valve disposed in a fluid conduit having a temperature affected by the presence of fluid flow, and producing a diagnosis of the condition of each drain valve as functional, clogged or stuck shut stuck open or cold fluid flow through the drain valve, comprising:
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at least one flow sensor, each flow sensor including a first heater attached to an exterior surface of the fluid conduit downstream of the drain valve, the heater, when energized, producing a thermal gradient along the conduit which varies as a function of fluid flow, a first temperature sensing element attached to the exterior surface of the fluid at a position spaced downstream of the heater and producing an output indicative of the temperature of the fluid conduit at the position of the first temperature sensing element, a second temperature sensing element attached to the exterior surface of the fluid conduit at a position spaced downstream of the first temperature sensing element, and producing an output indicative of the temperature of the fluid conduit at the position of the second temperature sensing element, means responsive to the outputs of the first and second temperature sensing elements, for producing a differential temperature output signal based on a difference between the temperature sensed at the first temperature sensing element and the temperature sensed at the second temperature sensing element, the differential temperature output signal having relatively greater and lesser values responsive to and thereby indicative of the presence and absence of fluid flow, and a second heater attached to the exterior surface of the fluid conduit downstream of the second temperature sensing element, the second heater, when energized, producing a thermal gradient along the conduit which varies as a function of fluid flow, drain valve position indicator means for producing and outputting a signal indicative of a selected position for each corresponding drain valve, operating condition indicator means for producing and outputting a signal indicative of an operating condition of the steam turbine, and control means responsive to the output signals of the operating condition indicator means, the differential temperature producing means, and the drain valve position indicator means for outputting a signal indicative of a diagnosis of each drain valve, and display means, for displaying the diagnosis of each drain valve. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A monitoring system for monitoring at least one drain valve disposed in a fluid conduit having a temperature affected by the presence of fluid flow, and producing a diagnosis of the condition of each drain valve as functional, clogged or stuck shut, stuck open, or cold fluid flow through the drain valves, comprising:
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at least one pair of flow sensors, one of the pair including a heater attached to an exterior surface of the fluid conduit downstream of the drain valve, the heater, when energized, producing a thermal gradient along the conduit which varies as a function of fluid flow, a first temperature sensing element attached to the exterior surface of the fluid conduit at a position spaced downstream of the heater and producing an output indicative of the temperature of the fluid conduit at the position of the first temperature sensing element, a second temperature sensing element attached to the exterior surface of the fluid conduit at a position spaced downstream of the first temperature sensing element, and producing an output indicative of the temperature of the fluid conduit at the position of the second temperature sensing element, and means responsive to the outputs of the first and second temperature sensing elements for producing a differential temperature output signal based on a difference between the temperature sensed at the first temperature sensing element and the temperature sensed at the second temperature sensing element, the differential temperature output signal having relatively greater and lesser values responsive to and thereby indicative of the presence and absence of fluid flow, the other of the pair of flow sensors including a second heater attached to an exterior surface of the fluid conduit at a position spaced upstream of the drain valve, the heater, when energized, producing a thermal gradient along the conduit which varies as a function of fluid flow, a third temperature sensing element attached to the exterior surface of the fluid conduit at a position spaced upstream of the second heater, and a fourth temperature sensing element attached to the exterior surface of the fluid conduit at a position spaced upstream of the third temperature sensing element, and second means responsive to the outputs of the third and fourth temperature sensing elements for producing a second differential temperature output signal based on a difference between temperature sensed at the third and fourth temperature sensing elements, the second differential temperature output signal having relatively greater and lesser values responsive to and thereby indicative of the presence and absence of fluid flow, drain valve position indicator means for producing and outputting a signal indicative of a selected position for each corresponding drain valve, control means responsive to the first and second differential temperature signals and drain valve position signal for outputting a signal indicative of a diagnosis of the drain valve, and display means responsive to the output signal of the control means, for displaying the diagnosis of the drain valve. - View Dependent Claims (16, 17)
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Specification