Once-through evaporator systems
AssigneeGeneral Electric Technology GmbH
InventorsPetrus Johannes Koller, Alexander Taylor
Life of this patent
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Abstract
The present application provides a method of adjusting a feedwater mass flow rate to maintain a constant steam temperature in an evaporator section. The method may include the steps of determining a change in a number of operational parameters, predicting a change in steam temperature based on the number of operational parameters, combining the predicted changes in steam temperature, determining a feedforward signal based on dynamically offsetting the combined predicted changes in steam temperature, and changing the mass flow rate of feedwater based on the feedforward signal.
Claims20
A method, comprising:
- determining changes in a plurality of operational parameters of a once-through evaporator section over a time interval during transient conditions;
- predicting a change in a steam temperature based on the changes in the plurality of operational parameters;
- determining a feedforward signal based on dynamically offsetting the predicted change in the steam temperature;
- and
- changing a feedwater mass flow rate of the once-through evaporator section based on the feedforward signal to maintain a constant steam temperature in the evaporator section during the transient conditions.
A once-through evaporator system, comprising:
- a plurality of once-through evaporator sections;
- and
- each once-through evaporator section of the plurality of once-through evaporator sections comprising an upstream distribution valve and a controller;
- wherein, for each once-through evaporator section of the plurality of once-through evaporator sections, the respective controller is configured to:
- determine changes in a plurality of operational parameters of the respective once-through evaporator section over a time interval during transient conditions;
- predict a change in a steam temperature based on the changes in the plurality of operational parameters;
- determine a feedforward signal based on dynamically offsetting the predicted change in the steam temperature;
- and
- provide the respective upstream distribution valve with the feedforward signal to change a feedwater mass flow rate of the respective once-through evaporator section to maintain a constant steam temperature in the respective once-through evaporator section during the transient conditions.
A system, comprising:
- a controller configured to change a feedwater mass flow rate of a once-through evaporator section based on a feedforward signal to maintain a constant steam temperature in the once-through evaporator section during transient conditions, wherein the feedforward signal is based on a dynamic offset of a predicted change in the steam temperature, the predicted change in the steam temperature is based on changes in a plurality of operational parameters of the once-through evaporator section, and the changes in the plurality of operational parameters are determined over a time interval during the transient conditions.
Dependencies are inferred from the claim text.