You can calculate how fast you can heat water (wort is probably not too different) - the biggest unknown is heat loss from the water (evaporation from the top, loss through the sides of the pot), and loss from the burner that doesn't even get into the pot. Assuming you have 6 U.S. gallons (about 50 pounds) of water and heat with 2700 watts with no heat loss at all, then your rate of temperature rise is:
(2.7 kW)(3412 BTU/hr KW)(1 lb ºF/BTU)/50 lb = 184 ºF/hr or 3.1 ºF/minute.
Realistically, you will lose quite a bit of heat, depending on a lot of factors, so I'd dial back the heating rate by 1/3 and guestimate that it's more like 120 ºF/hr. The other question is whether you can get to a boil at all. With no heat loss, of course you can. It comes down to whether the rate of heat loss as the wort nears boiling is greater than the rate you put heat in - you may need to insulate your kettle.