Automated DTS Testing via Integrated Peltier Cooling

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Solution Overview

Problem

Current distributed temperature sensing (DTS) systems for pipeline leakage detection lack a reliable and frequent method for testing their efficacy and reliability, making it difficult to meet Safety Integrity Level (SIL) certification requirements due to the complexity of software and the need for extensive proof of use, as manual testing is infrequent and insufficient.

Innovation Solution

An automated system with temperature change-inducing devices, such as Peltier coolers or heaters, is integrated into the sensing line to simulate leakage conditions continuously, allowing the DTS system to test its own reliability and accuracy by mimicking temperature changes that would occur during a leak, thereby generating data for SIL certification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual testing is performed periodically (annual or quarterly basis), then system operation is minimally disrupted and testing simplicity is maintained, but testing frequency is insufficient to generate adequate data for SIL certification

Engineering Contradiction:
Improvetesting frequencyVSAvoidtesting system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system uses test cables that are optically coupled into the sensing line and can autonomously generate temperature changes through integrated heating/cooling elements. The DTS system itself detects these changes, allowing the system to self-test without external manual intervention. This enables frequent automated testing while maintaining operational continuity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The sensing line is divided into functional segments: monitoring cables for actual pipeline monitoring and test cables for reliability testing. These segments are optically coupled together, allowing independent testing functionality while maintaining the overall system integrity. This segmentation enables targeted testing without disrupting the entire system.

Inventive Principle:
Principle #1Segmentation

2Reliability

If extensive proof of use is required for SIL certification, then system reliability confidence is improved, but testing time and resource requirements increase

Engineering Contradiction:
Improvesystem reliability confidenceVSAvoidtesting time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The automated testing system operates continuously or at frequent intervals, constantly generating reliability data. The test cables remain integrated in the sensing line, enabling uninterrupted testing that accumulates evidence of system reliability over time, directly supporting SIL certification requirements.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system proactively performs tests before actual leakage events occur by simulating temperature changes using the heating/cooling elements in test cables. This preliminary action allows the system to demonstrate its detection capabilities and accumulate reliability data without waiting for real leak conditions.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If temperature changes are simulated using manual methods, then testing simplicity is maintained and system complexity is minimized, but testing accuracy and consistency deteriorate

Engineering Contradiction:
Improvetemperature detection accuracyVSAvoidtesting device complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Test cables serve as intermediaries between the DTS system and the temperature simulation mechanism. These cables contain integrated heating/cooling elements that precisely control temperature changes at specific locations. The test cables translate electrical control signals into precise thermal effects that the DTS system can detect and measure accurately.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces manual mechanical temperature simulation (such as physical heating/cooling by personnel) with electronically controlled heating/cooling elements integrated into the test cables. This substitution enables precise, repeatable, and automated temperature changes while improving measurement accuracy and consistency.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The automated system enables continuous and autonomous testing of DTS systems, providing extensive data on reliability and response times, facilitating SIL certification by simulating leakage conditions and improving the frequency and efficiency of testing, thus enhancing the confidence in the system's performance.

Implementation Method 1

The DTS unit emits pulses of light through the sensing cables and receives backscattered light signals. These light signals are processed using ODTR techniques (Optical Time Domain Reflectometry) to derive therefrom temperature values associated with locations along the sensing line.

Methodology Applied
Scientific EffectOptical Time Domain Reflectometry (OTDR):

Implementation Method 2

The DTS unit emits pulses of light through the sensing cables and receives backscattered light signals

Methodology Applied
Scientific EffectLight backscattering: Scattering

Implementation Method 3

temperature change-inducing devices, such as Peltier coolers or heaters

Methodology Applied
Scientific EffectPeltier effect: Peltier Effect

Data Source

PatentEP2665993B1Automated system and method for testing the efficacy and reliability of distributed temperature sensing systems
Publication Date: 2019.04.10 ROCTEST LTEELTD
  • EP2665993B1 patent drawingFigure 1
  • EP2665993B1 patent drawingFigure 2
  • EP2665993B1 patent drawingFigure 3

AI summary

The present invention relates to automated systems for testing the efficacy and reliability of distributed temperature sensing (DTS) system. The DTS system has a fibre optic sensing cable laid out on a structure to be monitored, and a DTS unit for sensing temperature along a sensing line at locations thereof. The DTS unit is optically coupled to the sensing cable. The sensing cable is optically coupled to a test cable to form the sensing line. Also provided, is a cooling device for cooling the test cable. A controller periodically actuates the cooling device to thereby test the efficacy and reliability of the DTS system. A relay configured for communication with the DTS unit and the controller is operable to trigger an alarm condition if a temperature drop in the sensing line at a location thereof has been detected. The controller is operable to monitor the response of the DTS unit.