COMPUTER CONTROL SYSTEM FOR MULTIFUEL INDUSTRIAL BOILERS.

The Buick Motor Division of General Motors Corp. has constructed a new power plant to serve its Flint, Mich. complex. Two tangentially fired boilders were installed, and provision was made for two additional boilers. Each boiler has a maximum continuous rating of 400,000 lb/hr and is designed to burn pulverized coal as primary fuel, with sludge oil and industrial waste as secondary fuels. The boilers are controlled by a Series 16 digital computer system. Eight variables on each boiler are controlled by the computer. These are fuel flow, total air flow, coal air flow, furnace pressure, drum level, windbox-to-furnace differential pressure, and the temperature of each of two coal mills. Fuel flow and total air flow are controlled in a multi-loop, multi-variable configuration which maintains the steam header at set point pressure while balancing the load equally between the two boilers or maintaining a preset load division.