I don't know how it works, but I suspect that they do not keep changing. Ordered by PLAN but several of these being operated by research institutes.
There are a couple of examples of the changes at: https://mil-sina-cn.translate.goog/sd/2018-09-10/detail-ihiycyfw4007946.d.html?_x_tr_sl=zh-TW&_x_tr_tl=en
HAI YANG 20 / ZHU KEXHEN (872) and HAI YANG 24 / DENG JIAXIAN (874). There's a table here: https://en.wikipedia.org/wiki/Type_636_hydrographic_survey_ship
As they are fundamentally navy-owned, I suggest that best to keep in naval auxiliaries - unfortunately there seems to be nothing to use to link them (IMO, MMSI etc) so better at least in a single category.
See also https://www.shipspotting.com/photos/3556117 & 3556045

HAI YANG 27 (海洋二十七号) "Hai Yang" indeed translates as "ocean", but we normally transliterate ship names in non-latin scripts, rather than translate them..
This is the name when engaged in non-military activity.
If she was on naval service she would have the hull number (878) on the bow, and the name WANG GANCHANG.