Problem related to future tense?

不合文法。所述為「需要」時，這需要是現在及將來均屬真實的，應該用timeless present的「現在簡單式」: I need to go to Shenzhen this afternoon.

I will go to Shenzhen this afternoon.（所述為「預告」將來的行動時，才用「未來簡單式」。）

The simple future expresses possible or probable actions in the future:-
egGo to Shenzen
eg:-I shall go to Shenzhen (this afternoon.)