Steam Seal Dump Re-Entry Cooling for Turbine Vibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing steam turbines face performance issues due to thermal distortion and vibration caused by hot steam dump flow entering the low-pressure section, leading to decreased efficiency as the steam is too hot for the LP turbine components.
Innovation Solution
A steam seal dump re-entry system that cools the steam using a desuperheater before routing it back into the LP turbine, utilizing a temperature sensor and flow control circuit to ensure the steam is at a suitable temperature, preventing thermal distortion and optimizing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If steam dump flow is routed into the LP turbine, then performance gain is realized by allowing steam to expand and do work, but thermal distortion and vibration occur due to excessive heat
Solution Approach 1:
A desuperheater is introduced as an intermediary device between the steam seal header and the LP turbine. The desuperheater receives hot steam from the steam seal header, cools it by mixing with condensate water, and delivers cooled steam to the LP turbine. This intermediary component enables the steam to perform work in the turbine without causing thermal distortion, as the desuperheater reduces the steam temperature to an acceptable level before turbine entry.
Solution Approach 2:
The desuperheater changes the temperature parameter of the steam by cooling it from its original high temperature to a lower temperature suitable for LP turbine operation. By controlling the amount of condensate injected into the desuperheater, the steam temperature is adjusted to an optimal range that allows work extraction while preventing thermal distortion and vibration in the turbine components.
2Object-affected harmful factors
If steam is cooled in a desuperheater before entering the turbine, then thermal distortion is prevented, but system complexity increases due to additional components
Solution Approach 1:
The desuperheater utilizes condensate that is already present in the system (from the steam cycle) to cool the steam. The condensate supply is drawn from the existing steam cycle, and the cooling process is essentially a heat exchange between the hot steam and the cooler condensate. This self-service approach allows the system to cool the steam without requiring external cooling resources, thereby minimizing the increase in system complexity while still preventing thermal distortion.
3Power
If temperature control is implemented to prevent vibration, then turbine performance is optimized, but control system complexity increases
Solution Approach 1:
A temperature sensor is installed to monitor the steam temperature after cooling in the desuperheater. The temperature sensor provides feedback signals to the control system, which adjusts the amount of condensate injected into the desuperheater to maintain the steam temperature within the optimal range for LP turbine operation. This feedback mechanism ensures that the steam temperature is continuously controlled to prevent thermal distortion and vibration, while optimizing turbine performance, without requiring overly complex control logic.
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 system effectively cools the steam to prevent thermal distortion and vibration, enhancing turbine performance by allowing the steam to do work in the LP section, with estimated performance benefits of 200-250 kW, which increases over time as leakage flow increases.
Implementation Method 1
a desuperheater receiving and cooling the steam from the steam seal header
Implementation Method 2
a desuperheater receiving and cooling the steam from the steam seal header
Data Source
AI summary
A steam seal dump re-entry system delivers steam dump flow to an LP steam turbine. The system includes a steam seal header receiving steam leaking from turbine end seal packings, and a desuperheater receiving and cooling the steam from the steam seal header. The desuperheater outputs cooled steam. A temperature sensor is disposed downstream of the desuperheater and detects a temperature of the cooled steam. A flow control circuit communicating with the temperature sensor selectively delivers the cooled steam to at least one of the condenser and to the LP steam turbine depending on the temperature of the cooled steam.