As far as I know the only official designation that I have come across is PLANS = PLA Navy Ships. There is no abbreviation prefix for different class of ships. Some time we see wordings like DDG and FFG on banners, but the usage is not consistent, and could be unofficial.
Traditionally, from the late Qing dynasty, through Republic of China and People's Republic of China, normally a ship would be called by its class and name, example, Light Cruiser Chungking/ 重庆号輕型巡洋舰 (ROC Navy), Destroyer Shenzhen/深圳号驱逐舰 (PRC Navy).
This photo was taken onboard type 052D destroyer PLANS Changsha