Instrumentation and monitoring systems employing differential temperature sensors
First Claim
1. An instrumentation system for monitoring fluid conditions within the interior of a pressure vessel, comprising:
- at least one duplex differential temperature sensor comprising at least one pair of two substantially identical probes in communication with the fluid condition within the interior of the pressure vessel and two complementary sets of heater and temperature sensing elements, each such set being associated with a given pair of probes, the heater element being in one of the probes of the associated pair of probes and both probes of the pair having respective temperature sensing elements of the complementary set therein, and selectively operable, when energized, to heat the one probe, the one probe thus being a heated probe and the other probe being a reference probe, and to sense the temperatures of the heated and reference probes of the given pair and produce corresponding, sensed temperature outputs having a temperature differential therebetween, the temperature differential being of respectively higher and lower values in response to exposure of the pair of heated and reference probes of the sensor to steam and water conditions within the pressure vessel interior;
means for selectively energizing the heater element of a given one of the complementary sets of heater and temperature sensing element of a given sensor;
means for determining the temperature differential between the sensed temperature outputs of a given one of the complementary sets and producing a corresponding, sensed temperature differential output; and
control means, operative during a normal monitoring mode, for selecting one of the two complementary sets of the at least one sensor as an operative set and for maintaining the other of the two complementary sets thereof in a standby condition, the control means controlling the selective energizing means to energize the selected set and controlling the temperature differential determining means to determine the differential between the sensed temperature outputs of the selected set and produce a corresponding, sensed temperature differential output.
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Accused Products
Abstract
Instrumentation and monitoring systems utilize, as differential temperature sensors, heated, split-well thermowells of duplex design, mounted to the sidewall of a pressure vessel and communicating through a penetration in the sidewall with the fluid state within the vessel. Each probe has at least one parallel axial bore therein, a related, selected pair of probes receiving respective heater and temperature sensing elements in the associated bores and together functioning as a differential temperature sensor producing distinguishable, differential temperature outputs representative of the presence of steam versus water. The systems monitor the differential temperature outputs of plural such sensors to produce alarm indications and perform verification and error checking of the sensor output indications. Duplex sensor embodiments permit toggling between different, selected such pairs of probes for on-line testing and verification of monitored conditions represented by the sensor output indications and of the operability of the elements and supporting circuits, under automatic and manual controls, and with on-line substitution of complementary elements in the event of element failure.
80 Citations
30 Claims
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1. An instrumentation system for monitoring fluid conditions within the interior of a pressure vessel, comprising:
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at least one duplex differential temperature sensor comprising at least one pair of two substantially identical probes in communication with the fluid condition within the interior of the pressure vessel and two complementary sets of heater and temperature sensing elements, each such set being associated with a given pair of probes, the heater element being in one of the probes of the associated pair of probes and both probes of the pair having respective temperature sensing elements of the complementary set therein, and selectively operable, when energized, to heat the one probe, the one probe thus being a heated probe and the other probe being a reference probe, and to sense the temperatures of the heated and reference probes of the given pair and produce corresponding, sensed temperature outputs having a temperature differential therebetween, the temperature differential being of respectively higher and lower values in response to exposure of the pair of heated and reference probes of the sensor to steam and water conditions within the pressure vessel interior; means for selectively energizing the heater element of a given one of the complementary sets of heater and temperature sensing element of a given sensor; means for determining the temperature differential between the sensed temperature outputs of a given one of the complementary sets and producing a corresponding, sensed temperature differential output; and control means, operative during a normal monitoring mode, for selecting one of the two complementary sets of the at least one sensor as an operative set and for maintaining the other of the two complementary sets thereof in a standby condition, the control means controlling the selective energizing means to energize the selected set and controlling the temperature differential determining means to determine the differential between the sensed temperature outputs of the selected set and produce a corresponding, sensed temperature differential output. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. An instrumentation system for monitoring fluid conditions within the interior of a pressure vessel, comprising:
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at least one duplex differential temperature sensor having a pair of first and second substantially identical probes integrally interconnected at first ends thereof and extending in parallel axial relationship and spaced by a bilateral plane and adapted to be mounted to the sidewall of a pressure vessel with the probes in communication through a penetration in the sidewall with the fluid state within the interior of the pressure vessel, each said probe incorporating a heater element and a pair of associated temperature sensing elements, the heater element and a selected temperature sensing element of said first probe and a selected temperature sensing element of said second probe comprising a first differential temperature sensor component and the heater element of the said second probe and a selected temperature sensing element thereof and a selected temperature sensing element of said first probe comprising a second differential temperature sensor component; heater controller means for selectively supplying electrical power to said respective heater elements of said first and second probes of said sensor, the selected heater element heating the corresponding probe and raising the temperature thereof, in the absence of a fluid in the line contacting and dissipating heat from the probe, and thereby producing a difference between the temperatures sensed by the selected temperature sensing elements associated with the respective, heated and unheated probes of the sensor, said heater controller means further comprising means for determining operability of each of the heater elements of the sensor and producing an inoperative heater element output upon determining the inoperability of a heater element; temperature sensing element controller means for selecting the temperature sensing elements of the first and second probes and for monitoring the sensed temperature outputs of the selected temperature sensing elements, for providing a differential temperature output indicative of the difference between the respective, sensed temperature outputs of the selected temperature sensing elements of the first and second probes, and for determining the operability of the selected temperature sensing elements of the first and second probes; and system control means for controlling said heater and temperature sensing element controller means to select the heater and sensing elements of each sensor corresponding to the first sensor component thereof in a normal monitoring mode of the instrumentation system, for defining a normal differential temperature output condition, for detecting an alarm condition in the normal monitoring mode when the differential temperature output of the selected, first sensor component differs from the normal differential temperature condition, and for producing an alarm output in response to detecting an alarm condition; display means responsive to an alarm output of said system control means for producing an alarm display identified with the corresponding sensor; and said system control means being responsive to an inoperative heater element output from said heater controller for the selected heater of said first probe, corresponding to the first sensor component, for automatically causing said heater controller to select the heater element of the second probe and supply electrical power thereto and thereby to switch from the first to the second sensor component of the given sensor. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30)
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Specification