In the light of the problem of the superstandard dissolved oxygen in the feed water of the direct air-cooled unit, analyzes on the causes of the superstandard dissolved oxygen in the feed water of the power plant s boilers, and puts forward some measures for the corresponding treatment.

Causes and countermeasures for the load limit in summer for 600MW direct air-cooling units;

Causes of level imbalance among exhaust equipments in one 600 MW direct air-cooling unit during its speeding up process were found in this essay through analysis of its structure and operation mode.

In allusion to the non-uniform phenomenon of flow distribution caused by steam distributing pipe allocating steam to air- cooling element of direct air-cooling unit,flow distribution of steam distributing pipe of certain 200 MW direct air-cooling unit is numerically simulated via computational fluid dynamics software.

The operating conditions of cation-anion separated bed condensate polishing system used on direct air cooling unit have been inferred and summarized,pointing out the advantages and disadvantages of the said system and problems needing to pay attention in the process of its operation.

For the 4×600 MW direct air cooling units of Tuoketuo Power Generation Co.

)as well as the retrofitting cause of Av6+bypass control system of the indigenous first 2×600 MW direct air cooling units in Guodian Power Datong Power Generation Corporation,analyzes the control tactics of original Av6+bypass control system,puts forward the concrete retrofitting.