BOILER

摘要

A boiler is provided with: a boiler body in which the water level inside water pipes when combustion by a burner is stopped is lower than the upper ends of the water pipes; water supply means; control means which controls the water supply means depending on the water level in the boiler body; header water level detection means which detects a water level existing inside an upper header; and a downcast pipe. The control means performs first control for controlling the water supply means so as to lower a boiler body water level when the water level detected by the header water level detection means reaches a header set water level and second control for controlling the water supply means so as to raise the boiler body water level when the amount of drop in the boiler body water level reaches a predetermined amount after the first control.

主权项

1. A boiler comprising:
a boiler body including an upper header, a lower header, and a large number of water pipes to be heated by a burner, the water pipes connecting the upper header and the lower header to each other, wherein the water level in the water pipes when combustion by the burner is stopped is lower than the upper ends of the water pipes; water supply means supplying boiler feed water into the boiler body; control means controlling the operation of the water supply means depending on the water level in the boiler body; header water level detection means detecting a water level existing inside the upper header by boiler water inside the water pipes being pushed up by air bubbles generated by boiling of the boiler water; and downcast pipe allowing a lower part of the upper header and the lower header to communicate with each other, wherein the control means performs first control for controlling the operation of the water supply means so as to lower a boiler body water level when the water level detected by the header water level detection means reaches a header set water level and second control for controlling the operation of the water supply means so as to raise the boiler body water level when the amount of drop in the boiler body water level reaches a predetermined amount after the first control.