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Show I. TUBE TIC', ,.-----1-3-P--I -_D . .. ---., , PRIMARY • L _ ~y~~~ t!~ 'LE_R __ J r-----12-P-I .. -D-- -.. ., I SECONDARY • IL _S_U_P_E_R_H_E_A -T. _E_R .. ,.1• r-D- ---II-P-I- ---D- , REHEATER : L• ____________ J• LEGEND TIC r-------, ECONOMIZER L.. _____ ,--J TIC D - DIRTY METER TIC - THERMOOOUPLE 9PI,IIPI, 12PI, 13PI - PYROMETERS 5 Figure 3. Placement of instruments in convection section. Microcomputer Data AC9uisition System A data acquisitl0n system was required to collect and store all the signals from the new and existing plant instrumentation. The HP3497A Data Acquisition and Control Unit was chosen for its ease of use, proven reliability and expandability. It was provided with 16 outputs and 200 analog inputs used as follows: 93 Dirty Heat Flux Meters, 17 Clean Heat Flux Meters, 7 Pyrometer Locations, 18 Tube Metal Thermocouples, 40 Existing Pl ant Instrumentation Signals, 25 Spare Channels. A HP9817 technical microcomputer was used to control the data acquisition unit, process and store the data and produce colour displays representing the cleanliness of the boiler heat transfer surfaces. It was equipped with 570K byte RAH, a colour graphics interface and a IEEE-488 bus to which the data acquisition unit, printer and external disc drives were connected. The external disc drive was the HP9133XV which is a combination 3 1/2-inch 270K byte flexible disc and a 5 1/4-inch 14.5 M byte Winchester Disc. The Winchester disc was completely sealed and thus was excellent for the control room environment. It contained all software programs and a data file that coul d accommodate three weeks of ope rat i ng data logged every mi nute. Th e flexible disc was used to transfer programs and data from the plant to Waterloo and could contain thirty hours of data stored every three minutes. Software was written so that when the flexible disc was inserted in its drive it was immediately recognized and data would begin to be recorded on both di scs unt i 1 the fl exi b 1 e di sc was full. The Wi nchester di sc was rewri tten when full and thus always contained the data of the past three weeks of operation. |
