Patent Application
20190172597
The disclosed and claimed concept relates generally to nuclear apparatuses and, more particularly, to a heat pipe assembly having a detection system that employs fiber optic cable assemblies to detect temperatures at a number of locations on each of a plurality of heat pipes of a nuclear apparatus.
Numerous types of nuclear power generation systems are known to exist in the relevant art. Such nuclear power generation systems typically involve a nuclear reactor within which a fission reaction occurs. A fluid is pumped through the reactor to remove heat from the reactor, and the heated fluid is then typically passed through a heat exchanger in order to extract heat that is employed to operate a turbine that turns an electrical generator, by way of example.
Because of the extreme temperatures and other factors that are involved, it is desirable to know the various temperatures that are in existence at various locations in the nuclear environment. It is also known, however, that each temperature sensing device in the nuclear environment must be individually wired, and a very large number of temperature sensors can result in a correspondingly very large number of pairs of wires that connect the sensors to computerized data systems and the like. Improvements thus would be desirable.
An improved heat pipe assembly of a nuclear apparatus includes a number of elongated heat pipes and a detection system having one or more fiber optic cable assemblies that are elongated and are wrapped in a helical fashion along an exterior surface of one or more of the heat pipes. The detection system further includes an optical signal generator that supplies to each fiber optic assembly an optical signal and additionally includes a sensor that detects a number of reflections of the optical signal and generates an output. The output is usable by an instrumentation and control system to determine a number of temperatures along one or more of the heat tubes by detecting a temperature at each of a plurality of locations along each fiber optic cable assembly.
Accordingly, an aspect of the disclosed and claimed concept is to provide a heat pipe assembly of a nuclear apparatus wherein a detection system employs a fiber optic cable assembly that is, helically wound along an exterior surface of a heat pipe and that is used to detect a number of temperatures along the heat pipe.
Another aspect of the disclosed and claimed concept is to provide such a heat pipe assembly wherein the fiber optic cable assembly is wrapped in a helical fashion along each of a plurality of heat pipes in order to reduce the number of data channels that are required.
Another aspect of the disclosed and claimed concept is to provide a detection system that provides a temperature measurement at each of a plurality of locations from a single optical data channel.
Accordingly, an aspect of the disclosed and claimed concept is to provide an improved heat pipe assembly of a nuclear apparatus. The heat pipe assembly can be generally stated as including a number of heat pipes, the number of heat pipes each being, elongated and being of a substantially circular cross section, a detection system structured to determine a number of temperatures at each of a number of location along each of at least a subset of the heat pipes of the number of heat pipes, the detection system can be generally state as including at least a first fiber optic cable assembly that is elongated and is wrapped in a helical fashion onto an exterior surface of a heat pipe of the at least subset, the detection system can be stated as further including an optical signal generator that is structured to generate an optical signal and to supply the optical signal to the fiber optic assembly, the detection system can be stated as further including a sensor that is structured to detect a number of reflections of at least a portion of the optical signal from each of a number of locations along at least a portion of the length of the fiber optic assembly and to generate an output that is representative at least in part of at least some of the number of reflections, and an instrumentation system structured to receive the output and to determine, based at least in part upon the output, the number of temperatures.
A further understanding of the disclosed and claimed concept can be gamed from the following Description when read in conjunction with the accompanying drawings in which:
Similar numerals refer to similar parts throughout the specification.
An improved heat pipe assembly 4 is depicted generally in
The heat pipe assembly 4 further includes a detection system 16 that is configured to detect a number of temperatures at a number of positions along the longitudinal extent of each of a number of the heat pipes 12. As employed herein, the expression “a number of” and variations thereof shall refer broadly to any non-zero quantity, including a quantity of one. The detection system further includes a plurality of fiber optic cable assemblies, some of which are indicted at the numerals 20A, 20B, and 20C, and which may be collectively or individually referred to herein with the numeral 20. The detection system 16 can further be said to include a processing system 22 with which the fiber optic cable assemblies 20 are each connected.
The processing system 22 can be said to include an optical signal generator 24, a signal measurement apparatus 26 that includes an array of sensors 28, and an instrumentation and control system 32. The optical signal generator 24 is configured to generate an optical signal that is output to one or more of the fiber optic cable assemblies 20. The array of sensors 28 include a plurality of optical sensors, and each fiber optic cable assembly 20 has a corresponding optical sensor of the array of sensors 28.
When the optical signal generator 24 inputs an optical signal 34 to a first end of the fiber optic cable assemblies 20, portions of the optical signal 34 are reflected from various locations along the length of the fiber optic cable assemblies 20 back to the first end, and such reflected portions of the optical signal 34 are detected as a number of reflections 38 by the corresponding sensor 28. The time that has elapsed between the input of the optical signal 34 to the fiber optic cable assemblies 20 and the detections of the various reflections 38 by the array of sensors 28 is indicative of the distances from the first end along the fiber optic cable assembly 20 at which the various reflections occurred based upon the optical signal 34 traveling through the fiber optic cable assembly 20 at the speed of light. The amplitude of the detected signal of each such reflection 38 is indicative of the corresponding temperature at each such reflection location along the fiber optic cable assembly 20.
The fiber optic cable assemblies 20 each include a number of fiber optic cables 52 that are doped with various materials that are optimized to be responsive to temperature. The fiber optic cables 52 can be doped with other materials that are optimized to detect other properties of the heat pipes 12 if needed.
The signal measurement apparatus 26 generates a signal that is provided as an output 42 to the instrumentation and control system 32 and which is interpreted by the instrumentation and control system 32 into a plurality of temperatures at a plurality of locations along each of a number of the heat pipes 12. The instrumentation system 32 can then generate a visual output, such as is depicted generally in
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As a general matter, each fiber optic cable assembly 20 is capable of returning temperature reflections at two hundred locations along the length of the fiber optic cable assembly 20. In this regard, therefore, it can be understood that each fiber optic cable assembly 20 constitutes a single optical data channel that is capable of returning two hundred separate temperature values. By way of example, it may be desirable to detect the temperature at perhaps five locations along the longitudinal extent of each heat pipe 12. If, for instance, the heat pipe assembly 4 includes three thousand heat pipes 12, the detection of temperatures at five locations along each such heat pipe 12 would result in fifteen thousand measurement locations. If the aforementioned fifteen thousand temperature detections were made by fifteen thousand separate temperature sensors, this would result in a need for fifteen thousand coaxial or other wired data connections being connected between the heat pipes 12 and a data collection apparatus. This would require a large area for the passage of such wires, and the large number of wires and temperature sensors likely would have questionable reliability if only due to the large number thereof.
However, since a single fiber optic cable assembly 20 can return two hundred data values, i.e., one for each of two hundred locations along one or more of the heat pipes 12, this means that a mere seventy-five of the fiber optic cable assemblies 20 can be used to collectively result in fifteen thousand temperature data values. Employing seventy-five optical data channels as compared with fifteen thousand electronic data channels makes the detection of temperatures along the heat pipes 12 far more practical since optical temperature detection requires only one two-hundredth of the number of data channels as compared with individual electronic temperature sensors. This constitutes a substantial savings in space, cost, and reliability, which is highly advantageous.
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The temperature signal 46 is then sent to a drum control system 84 that controls a control drum that is employed to adjust the reactivity of the nuclear apparatus 8. The temperature data 80 is also sent to a comparator 88 which has stored therein various data regarding high temperature setpoints of the nuclear apparatus 8. The comparator 88 generates another output that is delivered to a computer-based trip decision matrix 92 which can decide through the use of various routines whether to initiate a shutdown of the nuclear apparatus 8.
It thus can be seen that temperatures can be detected at various locations along the heat pipes 12 with a minimum of data channels by employing optical data channels afforded by the fiber optic cable assemblies 20 and the processing system 22. This is enabled inasmuch as the fiber optic cable assemblies 20 each can generate two hundred temperature signals from a signal data channel. Other benefits will, be apparent.
While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular embodiments disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.
