Heat exchanger only using plural plates

A heat exchanger for performing a heat exchange between an inside fluid and an outside fluid, the heat exchanger comprising:

• plural pairs of heat-exchanging plates each having a plurality of projection ribs, each pair of said heat-exchanging plates facing each other in such a manner that, said projection ribs protrude outwardly to form therein an inside fluid passage through which the inside fluid flows, and to form an outside fluid passage through which the outside fluid flows between adjacent pairs of said heat-exchanging plates, wherein:
• said projection ribs protrude from flat surfaces of said heat-exchanging plates to said outside fluid passage to disturb a flow of the outside fluid;
• and
• said projection ribs are provided in each of said heat-exchanging plates to have a protrusion pitch (P1) between adjacent projection ribs, said protrusion pitch being in a range of 2-20 mm;
• said projection ribs extend in a direction approximately perpendicular to a flow direction of the outside fluid;
• said inside fluid passages are partitioned into a first inside fluid passage group and a second inside fluid passage group in the flow direction of the outside fluid;
• each pair of said heat exchanging plates have an inner leakage-detecting projection rib between said first inside fluid passage group and said second inside fluid passage group in the flow direction of the outside fluid, said inner leakage-detecting projection rib extending along said projection ribs;
• and
• said inner leakage-detecting projection rib has therein an inner leakage-detecting passage opened to an outside.

A heat exchanger for performing a heat exchange between an inside fluid and an outside fluid, said heat exchanger comprising:

• plural pairs of heat-exchanging plates each having a plurality of projection ribs extending in an extending direction approximately perpendicular to a flow direction of the outside fluid, each pair of said heat-exchanging plates facing each other in such a manner that said projection ribs protrude outwardly to form therein inside fluid passages through which the inside fluid flows, and to form an outside fluid passage through which the outside fluid flows between adjacent pairs of said heat-exchanging plates, wherein:
• said projection ribs protrude from flat surfaces of said heat-exchanging plates to said outside fluid passage to disturb a flow of the outside fluid;
• said inside fluid passages are partitioned into a first inside fluid passage group and a second inside fluid passage group in the flow direction of the outside fluid;
• each pair of said heat exchanging plates have an inner leakage-detecting projection rib between said first inside fluid passage group and said second inside fluid passage group in the flow direction of the outside fluid, said inner leakage-detecting projection rib extending along said projection ribs;
• and
• said inner leakage-detecting projection rib has therein an inner leakage-detecting passage opened to an outside.