Compared with the traditional vapor compression air conditioner

the pump-driven two phase cooling unit has a great potential in energy saving of data centers for it consumes less power and has a higher energy efficiency ratio when air temperature is low. However

insufficient control strategies not only hinder the improvement of performance

but also influence the accuracy of indoor temperature controlling

which limits the practical application. For a better application on small data centers

this paper designs a control system for the pump-driven two phase cooling unit

and studies its operating performance using in a small data center. This paper also fits the operating characteristic curves and makes an energy saving analysis. The results show that when the set point of indoor temperature is 22 ℃

the pump-driven system can fit the heat load well and get a good energy saving effect under the condition of an outdoor temperature of 10 ℃ or lower

and it can achieve at least a ratio of 26.77% on energy saving comparing with the existing air conditioner of the data center.