Patent Publication Number: US-3878401-A

Title: System and method for operating a turbine-powered electrical generating plant in a sequential mode

Description:
United States Patent i191 Ronnen 1 Apr. 15, 1975 [75] Inventor: Uri G. Ronnen, Monroeville, Pa.  
 [73] Assignee: Westinghouse Electric Corporation,  
 Pittsburgh, Pa.  
 [22] Filed: June 10, 1974 [21] Appl. No.: 478,815  
 Related U.S. Application Data [63] Continuation of Ser. No. 306,979, Nov. 15, 1972,  
 abandoned.  
 [52] U.S. Cl. 290/40; 235/l5l.2l; 444/1; 60/646 [51] Int. Cl...... G06j 1/00; G06f l5/O6; G06f 15/56 [58] Field of Search 235/l5l.2l, 151.34, 151.3, 235/151; 4l5/l,l3l4, 17; 60/646; 290/40 A40 C, 40 F; 444/1; 340/1725 OTHER PUBLICATIONS Application of the Prodac 50 System to Direct Digital Control; .1. C. Belz, G. J. Kirk &amp; P. S. Radcliffe, IEEE Int]. Conv. Rec. Part 3, 1965; pp. 102-122. Monitoring and Automatic Control in Steam Power Stations by Process Computer; E. Doetsch &amp; G. Hirschberg, Siemens Review XXXV(1968), No. 12; pp. 671-576.  
 Primary Examiner-Eugene G. Botz Assistant Examiner-Edward J Wise Attorney, Agent, or Firml-l. W. Patterson [5 7 ABSTRACT A system and method for operating a turbine power plant wherein a feedforward steam flow demand signal governs the partial-arc or sequential operation of the steam-turbine inlet valves, is disclosed. Each valve control group is governed sequentially according to the individual valve percentage of total steam flow that such valve is required to admit. The total steam flow demand signal is dynamically calculated in accordance with a demand percentage of total flow capacity of the unit, the steam throttle pressure, the number of nozzles associated with each valve, and the effect of impulse chamber pressure.  
 The steam inlet valves control the steam flow in the sequential mode throughout the range of steam flow demand by incrementally varying the valve lift positions within a predetermined operating range of steam flow. The valves of one group are fully open or closed only when such position permits the steam flow demand signal to control the sequentially adjacent valve group within the predetermined operating range. The extent to which the flow demand signal varies beyond the operating range of one valve group and below the predetermined operating range of the sequentially adjacent group determines the simultaneous direction of valve travel of adjacent valve groups, and which of the adjacent valve groups are controlling in the predetermined operating range. This range is varied with respect to the actual valve position in accordance with the total flow demand signal and the predetermined operating range is varied depending on the direction of steam flow demand change.  
 19 Claims, 45 Drawing Figures TTLE msssunsr DETECTOR lilo POWER n2 IMPULSE DETECTOR PRESSURE 9 DETECTOR STEAM LOAD TVI GVI 22 4 PDTI PDGI K 2 0mm TYPE BOILER STEAM M? [.F? L.F!  
 GENERATm g TURBINE TURBINE TURBINE GENERATOR svs&#39;rzu I SECTION SECTION SECTION I l 1 2s 32 1 L1 Tv4 eve REHEATER I STEAM sv 1V CONDENSER I T-OGB L g POI ANALOG DlGlTAL 46 SPEED SPEED DETECTOR DETECTOR so ,52 HYDRAULIC i THROTTLE GOVERNOR Sv 58 59 s| N Fri Simon: ACTUATOR NTROLS ONTROLS E 42 44 l 48 image &#39;tititti VALV VALV ACT AT 5s ACTUATORS AcTuArgns 49 U 5 7 POSITION men PRESSURE CONTROLS HYDRAULIC FLUID SUPPLY FILTER SUPPLY I I SUMP L ,322  
  GH 32: P SSURE T L SUPPLY TO ACTUATORS a &#34;f {In FILTER 4 SUMP 3 SUPPLY FIGB DEMODULATOR FILTER PATENTEDAPII I 5 I875 3. 8 7 8 4 U l SHEET 08 [1F 39 DATA PLANT COMMANDER PLANT wIRING L DATA TASK LINK INTERRUPT ERROR SEQEUEENCE OF v NTS &#39;Q LAMPS INTERRUPT &#34;58M PROGRAM -vALvE II32 I852] INTERRUPT PLANT CCI SUBROUTINE REFERENCE I854 s [IMO STATUS DEMAND PANEL PANEL LOGIC LAMPS WINDOWS INTERRUPTJ TASK TASKS AND CONTACTS SPEED Y OPERATOR SELECTION 2008 |9|Q PANEL H56 TURBINE BUTTONS PROGRAM 2022 vALvE WP &#34;30 (so .MANAGEMENT INTERRUPT \lsso R P2000 \20l8 THROTTLE CLOCK ERROR INTERRUPT 4 GOVERNOR 1 22 I4 I -IaI0 VALVES 1 AUXILIARY CONTROL I MONITOR HSYNCHRONIZER STOP TASK INITIAL TASK 1 52 1 I020 SPDLOOP H54 CARS. FRI??? 18.2 L FLASH POSITION TASK L CLOSE Gv H36 m ANALOG ScAN BREAKER II4I TASK OPEN INTERRUPT ATS U34 1 vISUAL BREAKER PLANT &#39;iffl INSTRUMENTATION H4 M ATS 0 PERIODICS lll8 CONTATTOLTJTPUTS 1 00 ATS H48 TEST ANALOG H TASK CONVERSION ANALOG I ROUTINE DISPLAY DIGITAL 1/ I W&#39;NDOWS TREND TYPEWRITERS PROGRAMMER MESSAGE II44 WRITER CONSOLE TASK  LOGGING TREND 8 TYPEWRITER RECORDER PATENTEDAPR 1 Bars 3 8 7 8 4 O l SHEET 0 7 BF 3 9 TABLE 1-1. TASK PRIORITY ASSIGNMENT FIG. 9  
  Core Level Function Frequency Location F STOP/INITIALIZE ON DEMAND 2F40 E AUXILIARY SYNCHRONIZER 0.1 SEC 14BD D CONTROL 1.0 SEC 2730 C OPERATORS PANEL ON DEMAND 2IBO B ANALOG SCAN 0.5 SEC 16D0 A ATS-PERIODICS 1.0 SEC 4420 9 LOGIC ON DEMAND 1962 8 VISUAL DISPLAY .10 SEC 11560 7 DATA LINK ON DEMAND SD10 6 ATS-ANALOG CONVERSIONS 5.0 SEC 6960 5 FLASH 0.5 SEC ISAO 4 PROGRAMMERS CONSOLE ON DEMAND 3000 3 ATS-MESSAGE WRITER 5.0 SEC 6CAO 2 ANALOG/DIGITAL TREND 1.0 SEC 31370 1 CCO TEST* ON DEMAND 0E80 0 BATCH PROCESSORS ON DEMAND 4000 *The CCO test task may be used only during maintenance and debugging periods, since this program overlays the data link progm area. &#34;The batch processors may be used only on manual control and with the sync disabled; also,  
 the sequence of events interrupt mme disabled since the batch processor programs overlay the ATS program area.  
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  26 &#39;(SEC) DECREAS ING RATE INCREASING REFERENCE PATENTEDAPR 1 51m 3, 878 .401 SHEET 19 0F 39 VALVE CURVE SELECTION SUB-PROGRAM TRANSFER CON&#39;I&#39;.  
 TO. INDIV. A/O  
  FLOW CHANGES 302 DURING A GV MODE TRANSFER COMPUTE TARGET COMPUTE TARGET FLOWS FOR FLOWS IN SEQ. MODE SINGLE MODE COMPUTE FLOW INCREMENTS AND NO. OF INCREMENTS NOCHGS=I FACT(I)=FTGT(I) DELF(I)=O v N TRFPG- NOVFOMO FALSE E YES  COMPUTS FULLY OPEN VALVE PO m N AND UPDATE ONE VALVE A/O&#39;s ONLY (EXIT) (EXIT) g FIGZBB