Dynamic matrix control of steam temperature with prevention of saturated steam entry into superheater
First Claim
1. A fuzzifier unit for use in a steam generating boiler system, comprising:
- a first input to receive a signal indicative of a magnitude of a difference between a saturated steam temperature and a temperature of intermediate steam generated by the steam generating boiler system that is a once-through boiler system providing a continuous flow of steam within the system to drive a turbine, wherein the temperature of the intermediate steam is determined upstream of a location at which a temperature of output steam is determined, the output steam generated by the steam generating boiler system for delivery to drive the turbine;
a second input communicatively coupling the fuzzifier unit to a dynamic matrix controller that is feed forward or predictive, the second input of the fuzzifier unit to receive a control signal generated by the dynamic matrix controller, wherein the control signal (i) is generated, by the dynamic matrix controller, based on a signal, received as an input by the dynamic matrix controller, that is indicative of a current rate of change of a disturbance variable used in the steam generating boiler system, and (ii) is generated, by the dynamic matrix controller, not based on any input, to the dynamic matrix controller, that is indicative of the temperature of the intermediate steam;
an adjustment routine that adjusts the control signal received at the second input of the fuzzifier unit based on the magnitude of the difference between the saturated steam temperature and the temperature of the intermediate steam; and
an output communicatively coupling the fuzzifier unit to a field device, the output of the fuzzifier unit to provide the adjusted control signal to the field device to control the temperature of the intermediate steam.
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Accused Products
Abstract
A technique of controlling a steam generating boiler system using dynamic matrix control includes preventing saturated steam from entering a superheater section. A dynamic matrix control block uses a rate of change of a disturbance variable, a current output steam temperature, and an output steam setpoint as inputs to generate a control signal. A prevention block modifies the control signal based on a saturated steam temperature and an intermediate steam temperature. In some embodiments, the control signal is modified based on a threshold and/or an adjustable function g(x). The modified control signal is used to control a field device that, at least in part, affects the intermediate steam and output steam of the boiler system. In some embodiments, the prevention block is included in the dynamic matrix control block.
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Citations
18 Claims
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1. A fuzzifier unit for use in a steam generating boiler system, comprising:
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a first input to receive a signal indicative of a magnitude of a difference between a saturated steam temperature and a temperature of intermediate steam generated by the steam generating boiler system that is a once-through boiler system providing a continuous flow of steam within the system to drive a turbine, wherein the temperature of the intermediate steam is determined upstream of a location at which a temperature of output steam is determined, the output steam generated by the steam generating boiler system for delivery to drive the turbine; a second input communicatively coupling the fuzzifier unit to a dynamic matrix controller that is feed forward or predictive, the second input of the fuzzifier unit to receive a control signal generated by the dynamic matrix controller, wherein the control signal (i) is generated, by the dynamic matrix controller, based on a signal, received as an input by the dynamic matrix controller, that is indicative of a current rate of change of a disturbance variable used in the steam generating boiler system, and (ii) is generated, by the dynamic matrix controller, not based on any input, to the dynamic matrix controller, that is indicative of the temperature of the intermediate steam; an adjustment routine that adjusts the control signal received at the second input of the fuzzifier unit based on the magnitude of the difference between the saturated steam temperature and the temperature of the intermediate steam; and an output communicatively coupling the fuzzifier unit to a field device, the output of the fuzzifier unit to provide the adjusted control signal to the field device to control the temperature of the intermediate steam. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification