The invention provides an automatic liquid supplementing
system of a rack-mounted CDU, which is arranged in a rack and comprises a liquid supplementing pipeline, a
secondary side circulation pipeline and a control module, a liquid supplementing water tank, a liquid supplementing pump and a liquid supplementing
pipe are arranged on the liquid supplementing pipeline, a
liquid level sensor for detecting the liquid level is arranged on the liquid supplementing water tank, a liquid outlet end of the liquid supplementing pump is connected with the
secondary side circulation pipeline, and a liquid outlet end of the liquid supplementing pump is connected with the
secondary side circulation pipeline. The liquid inlet end is connected with a liquid supplementing water tank or a liquid supplementing
pipe, and the liquid supplementing
pipe is connected with a
liquid storage device arranged outside the rack through a quick connector corresponding to an internal liquid supplementing mode or an
external liquid supplementing mode; a
pressure detection mechanism is arranged on the secondary side circulation pipeline, and the control module can control automatic liquid supplementing or liquid supplementing stopping and the liquid supplementing mode according to the pressure value detected by the
pressure detection mechanism and the liquid level value detected by the
liquid level sensor. By monitoring the pressure and the liquid level of the
cooling medium in real time, automatic switching between an
external liquid supplementing mode and an internal liquid supplementing mode can be achieved, automatic liquid supplementing is achieved, and the
system stability and the operation and maintenance efficiency are improved.