Remote temperature measurement

• US 4,655,992 A
• Filed: 01/24/1985
• Issued: 04/07/1987
• Est. Priority Date: 02/03/1984
• Status: Expired due to Fees

• Current Assignee: United Kingdom Atomic Energy Authority
• Original Assignee: United Kingdom Atomic Energy Authority
• Inventors: Macleod, Iain D., Burton, Eric J., McKnight, James A.
• Primary Examiner(s): Frankfort, Charles
• Assistant Examiner(s): Will, Thomas B.
• Application Number:
  US06/694,231
• Time in Patent Office: 803 Days
• Field of Search: 374/117, 374/118, 374/119, 374/120, 374/123, 374/124, 374/127, 376/247, 376/252
• US Class Current: 376/247
• CPC Class Codes: G01K 11/24 of the velocity of propagation of sound
• CPC Class Codes: G21C 17/025 for monitoring liquid metal coolants molten metal sampling in general G01N1/125
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

Temperature, or temperature noise, is measured by employing an ultrasonic beam which strikes at least one pair of points (10A, 10B) which are a known distance apart and the time interval between the two points is resolved and related to the distance to give a measure of temperature of the medium between the two points. The point pairs may be naturally occurring, such as the diametrically opposed edges of a fuel element channel in a sodium-cooled nuclear reactor, or specifically provided. The beam may be at glancing incidence on a number of point pairs in line and, in this situation, the beam is wider in the direction transverse to its path than it is along its path.

Claims

1. A method of measuring coolant fluid temperatures, said fluid emerging from outlets of an array of generally parallel fuel/breeder sub-assembly wrappers forming a core of a nuclear reactor, said method comprising projecting a beam of pulsed ultrasound transversely across the core at glancing incidence to said outlets of the wrappers and scanning said beam in a direction perpendicular to the beam direction whereby the beam propagates across the wrapper outlets in the array and undergoes reflection at diametrically-opposed edge portions of each of a plurality of said outlets located in different zones of the array, detecting echo signals produced as a result of such reflections, recording the timing of the echo signals with respect to pulsing of the beam, analysing the echo signals to relate them with the edge portions of respective wrapper outlets, and translating the timings of the so related echo signals into a temperature value for the coolant fluid emerging from the respective wrapper outlet.

2. A method as claimed in claim 1 wherein analysing the echo signals includes identifying those echo signals obtained when the scanned beam is normal to the diametrically-opposed edge portions.

3. In a nuclear reactor, apparatus for measuring coolant fluid temperatures, said fluid emerging from outlets of an array of generally parallel fuel/breeder sub-assembly wrappers forming a core of the nuclear reactor, said apparatus comprising ultrasonic transmit/receive transducer means for projecting a beam of pulsed ultrasound transversely across the core at glancing incidence to said outlets of the wrappers, means for effecting scanning of said beam in a direction perpendicular to the beam direction whereby the beam propagates across the wrapper outlets in the array and undergoes reflection at diametrically-opposed edge portions of each of a plurality of said outlets located in different zones of the array, means for detecting echo signals produced as a result of such reflections, means for recording the timing of the echo signals with respect to pulsing of the beam, means for analysing the echo signals to relate them with the edge portions of respective wrapper outlets, and means for translating the timings of the so related echo signals into a temperature value for the coolant fluid emerging from the respective wrapper outlet.

4. An apparatus as claimed in claim 3 wherein said analysing means includes means for identifying those echo signals obtained when the scanned beam is normal to the diametrically-opposed edge portions.