Hi David: A google search for "092 XIA" gives some 537 sites. Some are in Chinese and regretably, I can't read it to drill deeper into the information. One site, Chinese Defense Today: http://www.sinodefence.com/navy/sub/092.asp says it sub is twin shaft. Several of the sites refer to modifications and upgrades including changes in the paint scheme.
My best guess is it is a single screw type based upon some of the pictures. Since the description details claim there is only one (#406) and it was troubled with acoustic and reactor problems, I can understand the limited information. One recommendation is to look at the "HAN" class and 091 as everyone seems to agree they are the same.