Visa required? Flying in to Beijing with direct connect to Shanghai and leave Shanghai 2 days later

Hi

I arrive in Peking with a short layover of 2 hours before having a direct connecting flight to Shanghai.
In Shanghai, I intend on leaving the airport and staying there (in Shanghai) for 2 days.
After those two days, I will leave China again for Bangkok.

Will i need visa when being in T3? Will it be a change from International departure to national departure hall?

THANK YOU!