Low-Pressure Turbine Inlet Temperature Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing temperature estimation methods for aeroplane gas turbine engines are limited as they often require physical sensors at the inlet of the low-pressure turbine, which restrict design layout and must be highly heat-resistant, and existing methods estimate the inlet temperature of the high-pressure turbine rather than the low-pressure turbine.
Innovation Solution
A temperature estimation apparatus that uses sensors for rotational speed, ambient temperature, outlet temperature, and atmospheric pressure to calculate the inlet temperature of the low-pressure turbine by determining outlet temperature changes and applying correction factors, allowing for estimation without direct measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature sensor is installed at the inlet of the low-pressure turbine to directly measure the temperature, then the temperature measurement accuracy is improved, but the device complexity and design layout freedom are reduced, and the sensor must have excellent heat-resistance
Solution Approach 1:
The patent uses an intermediary calculation approach instead of direct measurement. It introduces intermediate parameters (high-pressure turbine outlet temperature, pressure ratios, mass flow rates) as mediators to indirectly determine the low-pressure turbine inlet temperature through thermodynamic relationships, avoiding the need to place a temperature sensor in the harsh high-temperature environment at the low-pressure turbine inlet
Solution Approach 2:
The patent creates a virtual temperature model by calculating temperature based on other measurable parameters rather than directly copying the physical temperature measurement approach. It uses a calculation formula that replicates the temperature information through alternative measurement paths (pressure, flow rate, and temperature at other locations)
2Measurement precision
If a temperature sensor is installed at the inlet of the low-pressure turbine, then the temperature can be directly detected, but the engine size increases and the design becomes less compact
Solution Approach 1:
The patent extracts the temperature measurement function from the physical sensor at the low-pressure turbine inlet and relocates it to sensors at more accessible locations (high-pressure turbine outlet and other positions). It separates the temperature detection function from the harsh environment and performs the measurement at locations with better accessibility and smaller space requirements
3Device complexity
If existing temperature estimation methods are used, then the need for direct temperature sensing is reduced, but they estimate the inlet temperature of the high-pressure turbine rather than the low-pressure turbine
Solution Approach 1:
The patent implements a dynamic estimation method that adapts to changing operating conditions. It uses real-time measurements of high-pressure turbine outlet temperature, pressure ratios, and mass flow rates to dynamically calculate the low-pressure turbine inlet temperature, making the estimation accurate across different engine operating states rather than relying on fixed relationships
Data Source
AI summary
In a temperature estimation apparatus for an aeroplane gas turbine engine, there are provided with a calculator that calculates a low-pressure turbine outlet temperature change (dEGT) based on low-pressure turbine rotational speed (N1) and ambient temperature (T1), a calculator that calculates a model outlet temperature (MODEL-EGTC) based on corrected high-pressure turbine rotational speed (N2C) and atmospheric pressure (P0) to calculate a model outlet temperature difference (dEGTC) by subtracting the calculated temperature (MODEL-EGTC) from a corrected low-pressure turbine outlet temperature (EGTC), a calculator that calculates a correction amount (dEGTad) relative to the model outlet temperature difference (dEGTC) based on the model outlet temperature difference (dEGTC) and low-pressure turbine rotational speed (N1), and a calculator that calculates an estimation value of the low-pressure turbine inlet temperature (ITT) based on the low-pressure turbine outlet temperature (EGT), etc., thereby enabling to estimate the inlet temperature of the low-pressure turbine.