| 主权项 |
1. A heat exchanger comprising:
a plurality of heat exchanging pipes, each of which is tube-type and has both ends open, and through the inside of each of which heating water passes; a first fixing plate and a second fixing plate, each of which has pipe insertion holes spaced apart in the lengthwise direction of the plate, such that both ends of the plurality of heat exchanging pipes are inserted into the respective pipe insertion holes; a first parallel flow channel cap and a second parallel flow channel cap fixed at the respective first fixing plate and second fixing plate to close both ends of the heat exchanging pipes and thus form a parallel flow channel, each of which having a plurality of dome-shaped portions and connecting portions connecting the dome-shaped portions; a heating water inlet connected to the first parallel flow channel cap; a heating water outlet connected to either the first or second parallel flow channel cap; and an insertion plate disposed between two adjacent pairs of heat exchanging pipes at a position corresponding to the connecting portion such that the two adjacent pairs of heat exchanging pipes are spaced apart, wherein each of the heat exchanging pipes has a plurality of first protrusions and a plurality of first recessions, the first recessions being depressed in the thickness direction of the heat exchanging pipe and also extending in the length direction of the heat exchange pipe, the first protrusions protruding in the thickness direction of the heat exchanging pipe and also extending in the length direction of the heat exchange pipe, and the first protrusions and the first recessions being alternately arranged in the width direction of the heat exchanging pipe so as to extend a flow path of combustion gas passing through between the heat exchanging pipes, wherein each of the heat exchanging pipes also has a plurality of second protrusions, the second protrusions protruding in the thickness direction of the heat exchanging pipe, also extending in the width direction of the heat exchange pipe and also being spaced apart in the length direction of the heat exchanging pipe, and the second protrusions facing each other of the heat exchanging pipes which are adjacent to form a pair being in contact with each other so that end surfaces of the second protrusions of the adjacent heat exchanging pipes are in contact in parallel with each other, thereby preventing the flow path of the combustion gas from being blocked by the expanding heat exchanging pipes, wherein end surfaces of the first protrusions of the heat exchanging pipe and end surfaces of the second protrusions of the heat exchanging pipe are connected to each other on a same plane, and wherein the insertion plate includes third protrusions extending in a lengthwise direction of the insertion plate and protruding towards the first recessions of the heat exchanging pipe while having a cross-sectional shape identical to a cross-sectional shape of the first recessions at a position facing the first recessions of the heat exchanging pipe that is facing one of two surfaces of the insertion plate, and second recessions depressed in an opposite direction to the protruding direction of the third protrusions while having a cross-sectional shape identical to a cross-sectional shape of the first protrusions at a position facing the first protrusions of the heat exchanging pipes that is facing one of the two surfaces of the insertion plate, in which the third protrusions and the second recessions are alternately arranged in the width direction of the insertion plates to extend the flow path of the combustion gas passing through between the heat exchanging pipes and the insertion plate. |
