Boost Compressor Temperature Control via Inlet Feedback
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Solution Overview
Problem
In gas turbine systems, controlling the temperature of cooling air produced by boosting compressed air from a compressor is challenging due to slow response times and inaccuracies, leading to potential damage from high or low temperatures, and the generation of condensed water.
Innovation Solution
A temperature control device that calculates temperature differences between the inlet and outlet of the boost compressor based on pressure ratios and IGV opening degrees, using this information for feedback control to adjust inlet and outlet temperatures to set values, while also considering operational status and surge avoidance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the outlet temperature of the boost compressor is controlled, then the cooling air temperature can be maintained, but the response becomes slow due to the influence of the pipe volume
Solution Approach 1:
The patent calculates the required inlet temperature to the boost compressor in advance based on the desired outlet temperature and the predetermined temperature difference (derived from pressure ratio and IGV opening degree). This preliminary calculation allows the control system to adjust the inlet temperature proactively, achieving faster response compared to controlling the outlet temperature directly, as the inlet temperature can be adjusted immediately without waiting for the compression process and pipe volume effects to manifest at the outlet.
Solution Approach 2:
Instead of controlling the outlet temperature of the boost compressor directly (which suffers from slow response due to pipe volume), the patent inverts the control approach by controlling the inlet temperature. The outlet temperature is then determined by adding the predetermined temperature difference to the controlled inlet temperature. This inversion of control point from outlet to inlet resolves the response speed issue while maintaining temperature control accuracy.
2Speed
If the inlet temperature of the boost compressor is controlled, then the response speed improves, but the outlet temperature changes due to compression and control accuracy deteriorates
Solution Approach 1:
The patent changes the parameter used for control calculation from direct outlet temperature control to inlet temperature control, using a predetermined temperature difference (ΔT) derived from the pressure ratio and IGV opening degree. By controlling the inlet temperature and adding the calculated ΔT, the system achieves both fast response (inlet temperature can be adjusted immediately) and accurate outlet temperature control (ΔT accounts for compression effects). This parameter transformation resolves the contradiction between response speed and control accuracy.
Solution Approach 2:
The patent employs feedback control where the actual outlet temperature is measured and compared with the target temperature. The measured outlet temperature is used to calculate the required inlet temperature by subtracting the predetermined temperature difference. This feedback loop ensures that despite variations in compression effects, the outlet temperature is accurately controlled while maintaining fast response through inlet temperature adjustment.
3Reliability
If the inlet temperature of the boost compressor is too low, then condensed water is generated which can damage the boost compressor and downstream devices
Solution Approach 1:
The feedback control system measures the actual outlet temperature and uses it to calculate the required inlet temperature. By continuously monitoring the outlet temperature and adjusting the inlet temperature accordingly, the system ensures that the inlet temperature remains above the dew point, preventing condensation formation. The feedback loop automatically compensates for temperature variations, protecting the boost compressor and downstream devices from condensation damage while maintaining optimal operating temperature.
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
This approach allows for more accurate temperature control of cooling air, preventing damage from excessive temperatures and condensation, and enhancing the reliability of the gas turbine system.
Implementation Method 1
cooling the air by a cooler
Implementation Method 2
boosting the air by a boost compressor... the temperature of the cooling air is increased
Data Source
AI summary
A temperature control device includes a temperature difference calculation unit that calculates a temperature difference between an inlet and an outlet of a boost compressor on the basis of a pressure ratio of the inlet and the outlet of the boost compressor and an IGV opening degree of the boost compressor, the boost compressor outputting cooling air obtained by cooling compressed air from a compressor to a cooling target; a temperature information calculation unit that calculates temperature information for feedback control for at least one of the inlet and the outlet of the boost compressor on the basis of the temperature difference between the inlet and the outlet of the boost compressor; and a control unit that performs feedback control by using the temperature information for feedback control such that at least one of an inlet temperature and an outlet temperature of the boost compressor approaches a setting value.