I tried using Ctrl+= as well as Quantity. I get no implicit conversions. And again, if I evaluate your cells in place, I do not get the outputs you had in there originally.
I also notice that your outputs are actually wrong in the sense that if a conversion had occurred, it's faulty (which seems even worse than implicit conversion itself). Specifically, 80 degrees celcius is closer to 350 kelvins than to the over 1100 kelvins that appears in your notebook.
So, my first suspicion is that there were some previous calculations that you haven't shown us that set up some variables or functions that are being applied in these expressions. (You could test this by killing and restarting the kernel.)
If that's not it, then maybe there is some setting/preference that is set differently in your environment than in mine. Maybe there are options for automatically converting certain units. Seems unlikely, but I'm just brainstorming here.
