You Do Need power plug adapter while traveling from Ireland (Eire) to China.

Here is Why You Need An Adapter

The outlet and plug type used in China are A, C and I and in Ireland (Eire) is G. This is how they look like.

Ireland (Eire)

In Ireland (Eire), outlets of type G are in use.

Type G

China

In China, outlets of type A, C and I are in use.

Type A

Type C

Type I