Dual-Sensor Temperature Probe for Gas Flow Enthalpy

Solution Overview

Problem

Temperature measurements in gas flows, particularly in gas turbine engines, are inaccurate due to the influence of flow velocity, leading to underestimation of specific enthalpy and resulting errors in thermodynamic parameter calculations, especially at higher Mach numbers.

Innovation Solution

A temperature probe with both free flow and total temperature sensors, where the total temperature sensor is placed in a stagnation area to accurately measure specific enthalpy, and the free flow sensor detects transient changes, minimizing errors caused by kinetic energy conversion to thermal energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If temperature measurement is performed in a stagnation area to accurately represent specific enthalpy, then measurement precision is improved, but response time increases due to low gas replacement rate

Engineering Contradiction:

Improvetemperature measurement accuracyVSAvoidresponse delay

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The probe is divided into two distinct sensing zones: a stagnation area sensor for accurate total temperature measurement and a free-flow sensor for rapid response. Each sensor serves a specific function, and their measurements are combined to achieve both precision and speed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent combines measurements from two different sensor locations (stagnation area and free-flow regions) into a single integrated temperature indication. This merging allows the system to leverage the advantages of both measurement approaches simultaneously.

Inventive Principle:

Principle #5Merging (Combining)

2Loss of time

If temperature measurement is performed in free flow to detect transient changes quickly, then response time is improved, but measurement precision deteriorates due to kinetic energy effects

Engineering Contradiction:

Improveresponse delayVSAvoidtemperature measurement accuracy

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

The probe is divided into two distinct sensing zones: a stagnation area sensor for accurate total temperature measurement and a free-flow sensor for rapid response. Each sensor serves a specific function, and their measurements are combined to achieve both precision and speed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent combines measurements from two different sensor locations (stagnation area and free-flow regions) into a single integrated temperature indication. This merging allows the system to leverage the advantages of both measurement approaches simultaneously.

Inventive Principle:

Principle #5Merging (Combining)

3Measurement precision

If only total temperature sensor in stagnation area is used to measure specific enthalpy, then measurement precision is improved, but device complexity increases due to additional sensors and processing

Engineering Contradiction:

Improvespecific enthalpy measurement accuracyVSAvoidsensor and processing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The dual-sensor probe serves multiple functions: it measures both total temperature (for specific enthalpy) and free-flow temperature (for transient detection), providing comprehensive flow characterization with a single device rather than requiring separate measurement systems.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 solution provides accurate and fast measurements of total temperature and specific enthalpy, reducing errors and enabling timely detection of transient changes, even at high flow velocities and off-design flow conditions.

Implementation Method 1

In a stagnation area the dynamic pressure head of the flow is converted into static pressure, the kinetic energy of the flow is converted into thermal energy

Methodology Applied

Scientific EffectKinetic energy conversion to thermal energy: Aerodynamic Heating

Implementation Method 2

at least one temperature sensor is provided as a free flow temperature sensor to measure a free flow temperature of the gas flow

Methodology Applied

Scientific EffectTemperature sensing: Thermocouple

Data Source

PatentUS10481017B2Temperature probe

Publication Date: 2019.11.19 ANSALDO ENERGIA SWITZERLAND AG

AI summary

A temperature probe and method for determining a temperature in a gas flow are disclosed. The probe includes a probe body. A free flow temperature sensor a free flow temperature of the gas flow and a total temperature sensor measures a total temperature of the gas flow. The method includes measuring a flow temperature in a free gas flow, providing a static gas volume in which essentially all kinetic energy of the flowing gas is recovered and converted into thermal energy, and measuring a total temperature in the static gas volume. An accurate determination of the total temperature of a gas flow, which is representative of a specific total enthalpy, can thereby be achieved while detecting fast and transient temperature changes.