Air-Cooled Condenser Control Method for Power Plant Fan Reliability
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Solution Overview
Problem
Existing control systems for air-cooled condensers in electric power generation plants frequently undergo unnecessary state transitions due to inadequate accounting for steam condition evolution, leading to increased risk of malfunction or breakage from frequent speed changes and high power absorption by fans, which can cause transformer overloads and mechanical wear.
Innovation Solution
A control method for air-cooled condensers that uses a state management module to selectively adjust fan operating conditions based on pressure error, integral, and derivative values, minimizing state transitions by employing a dead band and thresholds to prevent excessive fan speed changes and ensure proper motor demagnetization, thereby reducing wear and preventing overloads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fan speed is frequently adjusted to respond to steam condition changes, then condenser performance is maintained, but mechanical wear increases and reliability decreases
Solution Approach 1:
The system dynamically adjusts fan speed based on steam conditions (pressure, temperature, flow rate) while incorporating a dead band mechanism that prevents unnecessary state transitions. The control system evaluates whether changes in steam conditions exceed predetermined thresholds before initiating fan speed changes, thereby optimizing condenser performance while reducing mechanical wear and improving reliability.
2Use of energy by moving object
If fan speed changes are made frequently to match steam conditions, then cooling efficiency is improved, but transformer overloads occur and device complexity increases
Solution Approach 1:
The control system continuously monitors steam conditions (pressure, temperature, flow rate) and provides feedback to the fan speed control mechanism. A dead band threshold is implemented where fan speed remains constant unless steam condition changes exceed predetermined limits, preventing excessive state transitions and transformer overloads while maintaining adequate cooling efficiency.
3Duration of action of stationary object
If fan speed is reduced to minimize wear, then mechanical part lifespan is extended, but condenser performance may be compromised
Solution Approach 1:
The system changes the operational parameters of fan speed based on actual steam conditions rather than maintaining constant speed. By implementing a dead band mechanism that prevents unnecessary speed changes, the system extends mechanical part lifespan by reducing wear from frequent transitions while maintaining condenser performance through appropriate speed adjustments when steam conditions genuinely require them.
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 method reduces unnecessary state transitions, minimizing the risk of malfunction, preventing transformer overloads, and extending the lifespan of mechanical parts by optimizing fan operation and reducing wear through controlled speed adjustments.
Implementation Method 1
condenses the steam deriving from the steam turbine or from by-pass systems with which steam turbines are normally provided, transferring the residual heat into the atmosphere
Implementation Method 2
The major fraction (about 90%) of the steam is condensed into tube bundles thus condensed by means of fans belonging to primary modules
Implementation Method 3
a plurality of fans, organized as a matrix in rows and columns and arranged so as to cool the steam flowing through the tube bundles
Data Source
Figure 1
Figure 2~4
Figure 5~6
AI summary
A control method for an air condenser of an electric power generation plant, provides detection of a control quantity (PA) indicative of conditions of a steam flow supplied to the condenser (8), and the selection of a state (SK, SK') of the condenser from among a plurality of available states (S1, ..., SP), on the basis of the detected control quantity (PA) and of a reference value (PR). A first condition (C1), a second condition (C2), and a third condition (C3) are verified, concerning respectively the control quantity (PA), to a an integral of the control quantity (PA) and to a derivative of the control quantity (PA), in relation to the reference value (PR). State changes of the selected state (SK, SK') are decided on the basis of the first condition (C1), the second condition (C2) and on the third condition (C3).