Enter PVG, depart, re-enter Tianjin

We arrive from US to PVG March 27, five days before a cruise. Ship departs April 1 sailing to Seoul then returns to China at Tianjin port on April 5. Ship in port for 2 nights and departs on April 7 sailing back to South Korea and on to ports in Japan. Can we take advantage of 144 hr visa free travel in Shanghai and then again in Tianjin? Thank you for information.