Superheated steam flows through steel pipes in the utility tunnel network below the sidewalks on our campus. In the winter, the cold air in these tunnels is warmed by the steam flowing through the pipes. The largest pipe is 0.4 m in diameter, carrying high energy steam across campus. This steam is leaves the powerplant at 1 MPa, 600 oC at a velocity of 10 m/s. By the time it reaches the other side of campus, the steam pressure and temperature drops to half those values (0.5 MPa and 300 oC). This energy loss is due almost entirely to heat exchange with the cold air in the tunnels; estimate how much energy could be saved each winter day (24 hr period) by insulating the pipe ?