am i eligible for 144 hrs visa for 2 cruises out of Tianjin?

Leaving from Canada to Dubai (3 days)
Dubai to Beijing (2 days) then go to Tianjin for a 7 day cruise to Japan.
Return to Tianjin, and same day leave for 2nd cruise for 12 days: Japan, Taiwan, Hong Kong, and 2 stops in Vietnam before final stop in Singapore.