Plant unit master control for fossil fired boiler implemented with a digital computer
First Claim
1. A system for controlling the operation of a fossil fired boiler-steam turbine plant, said system comprising:
- (a) boiler control means responsive to an electrical representation of load demand reference for operating the fossil fired boiler to meet the load demand reference;
(b) an electrohydraulic control system for operating the turbine valves to direct steam from the fossil fired boiler to the turbine;
(c) turbine control means responsive to the electrical representation of the load demand reference for controlling the operation of said electrohydraulic control system to direct steam into the turbine so that the turbine meets the plant load reference;
(d) coordinated control means for providing the electrical representation of load demand reference in parallel to said turbine control means and to said boiler control means whereby coordinated control of the fossil fired boiler and steam turbine is achieved;
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Accused Products
Abstract
An electric power plant, including a fossil fired boiler and a steam turbine, is operated by a control system including a plant unit master. The control system includes a boiler control for determining the inputs of fuel, air and water, and a turbine control for determining the position of the throttle valves introducing steam from the boiler to the turbine. The plant unit master provides a load demand reference in parallel to the boiler control and to the turbine control, whereby the turbine and the boiler are operated in a coordinated manner. Measuring means provide indications of throttle pressure, power generated by the system and turbine rotor speed. Distinct controllers, each including a controller and responsive to one of the aforementioned indications and its corresponding reference, modify the load demand reference before it is applied to the turbine control or to the boiler control. The above-described control system including the plant unit master, boiler control and turbine control is implemented by a single digital computer.
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Citations
32 Claims
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1. A system for controlling the operation of a fossil fired boiler-steam turbine plant, said system comprising:
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(a) boiler control means responsive to an electrical representation of load demand reference for operating the fossil fired boiler to meet the load demand reference; (b) an electrohydraulic control system for operating the turbine valves to direct steam from the fossil fired boiler to the turbine; (c) turbine control means responsive to the electrical representation of the load demand reference for controlling the operation of said electrohydraulic control system to direct steam into the turbine so that the turbine meets the plant load reference; (d) coordinated control means for providing the electrical representation of load demand reference in parallel to said turbine control means and to said boiler control means whereby coordinated control of the fossil fired boiler and steam turbine is achieved; - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 28, 29, 30, 31, 32)
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2. (e) means for generating electrical representations of throttle pressure and generated power;
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3. (f) said coordinated control means including first and second, distinct control loops responsive to the representations of throttle pressure and generated power, respectively, and each including an integrating controller responsive to the difference between its one representation and a corresponding reference value to modify the load demand reference applied to said boiler control means, and a third control loop including an integrating controller, responsive to the difference between the representation of throttle pressure and a throttle pressure reference for modifying the load demand reference applied to said turbine control means, said integrating controllers capable of processing its input difference signal with varying constants dependent upon the system mode of operation.
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25. A system for controlling the operation of a fossil fired boiler-steam turbine plant, said system comprising:
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(a) turbine control means responsive to an electrical representation of load demand reference for operating the boiler to meet the load demand reference;
(b) an electrohydraulic control system for operating the turbine valves to direct steam from the fossil fired boiler to the turbine;
(c) boiler control means responsive to the electrical representation of the load demand reference for controlling the operation of said electrohydraulic control system to direct steam into the turbine so that the turbine meets the load demand reference;
(d) coordinated control means for providing the electrical representation of load demand in parallel to said turbine control means to said boiler control means whereby coordinated control of the fossil fired boiler and steam turbine is achieved; and(e) said turbine control means, said boiler control means and said coordinated control means are implemented in a single computer having a central memory.
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Specification