Fan-assisted forced flow air-cooling heat exchanger system

Claim 1

In a forced flow system for heat exchange between a first fluid flowing inside ducts of a set of flat planar heat exchangers and a second fluid passing over the outside surfaces of the heat exchangers, said system including a vertical chimney terminating at its bottom in a radially enlarged chamber opening horizontally to admit air flow to said chimney, a fan placed in said chimney above said chamber and said heat exchangers positioned within said chamber such that said second fluid passes over the outside surfaces of the heat exchangers, the improvement wherein said heat exchangers are vertically oriented, are positioned within said chamber at a radial distance in excess of the radius of said chimney, constitute a circumferential array, and are angularly oriented relative to each other, and said heat exchangers including means defining horizontal air flow paths through said heat exchangers such that the streams of said second fluid emerging from the heat exchangers form on the average, in a plane perpnedicular to the axis of rotation of the fan, an angle α with the local radii emenating from the meeting point of said axis with said perpendicular plane, said angle α being calculated such that during average operation of the assembly, the angular momentum of said second fluid in relation to the axis of the fan, at the output of the heat exchangers, is substantially equal but in the opposite direction to the angular momentum imparted to said second fluid by the rotation of the fan, such that the angular momentum resulting from the second fluid in relation to the axis of the fan will be close to zero at the output of the fan.