Results from tests of the P-67 boiler used as part of a 800-MW power unit

Results from the balance tests of a retrofitted P-67 boiler carried out in the period 2006–2008 are presented. The tests involved assessment of the change with time of the heating-surface thermal efficiency coefficients in running the power unit at its base loads in the range 740–800 MW, with seven to eight coarsegrinding mills switched into operation, with the open and closed gate values installed in the channels supplying air-powder mixture to the fourth-tier burners, and with the fraction of air supplied for lower blasting equal to 5–7% and that for the startup burners, 2%. The combined cleaning system operated in its design mode with additional blowing operations according to special control signals. The furnace waterwalls and the convective shaft surfaces were subjected to mechanical cleaning every year during current repairs.