Heat transfer fin and fin-tube heat exchanger

A fin-tube heat exchanger comprising:

• a plurality of heat transfer fins arranged spaced apart from and parallel to each other;
• and
• a plurality of heat transfer tubes penetrating the heat transfer fins,
• the fin-tube heat exchanger being for exchanging heat between a first fluid flowing on surfaces of the heat transfer fins and a second fluid flowing inside the heat transfer tubes, wherein:
• the plurality of heat transfer tubes include a first heat transfer tube and a second heat transfer tube, both arranged in a predetermined row direction intersecting a flow direction of the first fluid;
• each of the heat transfer fins has a protuberance and a cut-out between the first heat transfer tube and the second heat transfer tube, the protuberance protruding from the surface of the fin and guiding the first fluid toward the first heat transfer tube and toward the second heat transfer tube, and the cut-out being formed upstream of the protuberance with respect to the flow direction of the first fluid;
• each protuberance has, as an upstream portion adjacent to the cut-out, a wing portion tapering toward an upstream side,
• each heat transfer tube is a heat transfer tube that is located at a position immediately adjacent to a leading edge portion of the heat transfer fin;
• and
• a portion or an entirety of the wing portion is located upstream of a line passing through the center of the first heat transfer tube and the center of the second heat transfer tube, with respect to the flow direction of the first fluid.

A fin-tube heat exchanger for exchanging heat between a first fluid and a second fluid, comprising:

• a plurality of heat transfer fins arranged spaced apart from and parallel to each other so as to form a space for allowing the first fluid to flow therethrough;
• and
• a plurality of heat transfer tubes for allowing the second fluid to flow therethrough, the plurality of heat transfer tubes penetrating the plurality of heat transfer fins and arranged in a predetermined row direction intersecting a flow direction of the first fluid, wherein:
• each of the heat transfer fins has:
• (a) a protuberance formed between a first heat transfer tube and a second heat transfer tube that are adjacent with respect to the row direction;
• and (b) a hole formed along an upstream portion of the protuberance with respect to the flow direction of the first fluid so that, when the first fluid flowing along a principal surface of the heat transfer fin reaches the protuberance, the first fluid is allowed to flow from a first principal surface side to a second principal surface side of the heat transfer fin;
• the protuberance and the hole are mirror symmetrical with respect to a mirror plane of symmetry that contains a perpendicular bisector of a line segment, the line segment connecting a center of the first heat transfer tube and a center of the second heat transfer tube at the shortest distance;
• a boundary line between the protuberance and the hole, that is observed when the heat transfer fin is viewed in plan, forms a protruding shape toward an upstream side with respect to the flow direction of the first fluid;
• each protuberance has, as the upstream portion whose contour is defined by the boundary line, a wing portion whose width along the row direction decreases toward the upstream side with respect to the flow direction of the first fluid,
• each heat transfer tube is a heat transfer tube that is located at a position immediately adjacent to a leading edge portion of the heat transfer fin;
• and
• a portion or an entirety of the wing portion is located upstream of a line passing through the center of the first heat transfer tube and the center of the second heat transfer tube, with respect to the flow direction of the first fluid.