A balance between condensing and boiling heat exchange is an important prerequisite for the efficient and stable operation of two-phase immersion liquid cooling systems. In this study

the effects of the condensate tube type and cooling water parameters on the balance of the condensing and boiling heat transfer of the system were studied experimentally. The results show that the system achieved heat balance when the heat exchange rate of the condensate tube was not lower than the pool boiling heat transfer rate of the dielectric liquid

and the required flow rate of the cooling water was minimized when the heat exchange in the system was exactly balanced. The performance of the 3D-enhanced tube was better than that of the smooth tube

and a lower cooling water flow rate was required for the system to achieve the same cooling water inlet temperature. The highest coefficient of performance (COP) of the system was obtained when the heat exchange in the system was perfectly balanced. At a heat load of 210 kW/m2

the highest COPs of the system obtained using the smooth tube

outer enhanced tube

and double-sided enhanced tube were 4.5

6.9

and 7.6

respectively. However

the COP decreased as the flow rate of the cooling water increased after the heat exchange balance in the system was achieved. When the flow rate of the cooling water increased to 1.5

2.7

and 3.8 times the flow rate that achieves heat exchange balance

the COP of systems with the smooth tube

outer enhanced tube

and double-sided enhanced tube decreased by 39.0%

60.1%

and 69.2%

respectively.