Transfer time enough for Air China from Wuhan to get to International flight to London LHR ?

My son has booked a Air China flight back from Wuhan to London on 30th Aug 2019. We booked everything through the Air China website and both planes are operated by them (we think) - details below. One arrives T3 and the other also takes off from T3. What is the process he will go through in terms of any security checks or other checks - bit concerned about 1hr 45 min time between arriving and taking off (but the website showed these times).

Arrive 14:40
CA8203, Wuhan,Tianhe International Airport(WUH) 12:40 Capital International Airport(PEK)-Terminal 3 14:40 Class: Economy Class (T) Fri 30 Aug 2019 Air China (CA)Non-Stop/Direct 2h00m

Take off 16:35
CA855, Capital International Airport(PEK)-Terminal 3 16:25 London ,Heathrow Airport(LHR)-Terminal 2 20:40 Class: Economy Class (T) Fri 30 Aug 2019 Air China (CA)Non-Stop/Direct 11h15m