091 and 092 are partially retired by now.
093 the second generation SSN.
093A has a streamlined sail.
093B has a mini turtle back.
093B1 has a streamlined mini turtle back.
093B2 the mini turtle back almost disappeared.
Two 093B2
093B3? The sail is reshaped.
091
092
093
093A
093B2
Two 093B2
094
094A
In naval base.
Two 093 taken in 2011.
Three 094 and one 093 taken in 2014.
Two 093B2 taken in 2018.
093B1
093B2
In summary, the variants and sub-variants of 093/093A/093B.
In JCZS they lumped 093B1/2/3 together as 093B2. So 093 appeared to have three sub-class, four variants according to JCZS, and up to six sub-variants being observed.
Related link: PLAN 2021 first update