| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a liquid circulation control device that detects the presence or absence of liquid in a pipe forming a circulation route without using a flow switch, a flow sensor, or the like. <P>SOLUTION: The liquid circulation control device includes a pump drive means that sets a circulation pump rotation speed at which a predetermined circulation flow rate of liquid in the pipe forming the circulation route is obtained and supplies a drive voltage for driving at the set rotation speed to the circulation pump, and a pump rotation detection means that detects the actual rotation speed of the circulation pump from the circulation pump. If the actual rotation speed detected by the pump rotation detection means reaches the maximum rotation speed at the drive voltage for driving at the set rotation speed, the absence of liquid in the pipe is determined. <P>COPYRIGHT: (C)2012,JPO&INPIT |
