visa for China- 144 hour visa

Thank you John Doe for your reply on Jan 11, 2020.
Just one clarification that I do not stay in hotel and come back to ship after day visits and sail to next port. The total time that the ship first time docks on Tianjin, mainland China (9:00am on Sept. 18, 2020) to finally leaving Ximen, mainland China (9:00am on Sept. 23, 2020) is 5 days (120 hours) including time spent on sea. I understand the the visit to Hong Kong will not count.
Does this itinerary qualify for 144 hour visa free entry instead of regular tourist visa? Is there a limitation on the number of ports under 144 hour visa free entry.
If the itinerary is eligible for 144 hour visa free entry, where to apply for this Visa? Will it be at Tianjin?
Thanks again.
Virendra Charan