A brazed plate heat exchanger

Abstract

A brazed plate heat exchanger (10) comprising a stack of heat exchanger plates (12a, 12b) provided with a pattern comprising ridges (R) and grooves (G) to form plate interspaces (13a, 13b) for fluids to exchange heat. The heat exchanger plates are provided with port openings (O1-O4) forming inlet and outlet channels (14) for the first and second fluids, wherein at least one of the first and second heat exchanger plates is arranged with a skirt to form a chamber (17) between the port opening and the plate interspaces. The chamber (17) is open to the channel (14) through a gap between at least a free end portion of the skirt and the adjacent heat exchanger plate, and the gap varies around the circumference of the channel (14) and/or a cross section area of the chamber (17) varies around the circumference of the channel (14).

1 . A brazed plate heat exchanger comprising a stack of at least first and second heat exchanger plates each provided with a pattern comprising ridges and grooves adapted to form contact points between neighboring heat exchanger plates such that plate pairs of the heat exchanger plates form alternating first and second plate interspaces for first and second fluids to exchange heat over the heat exchanger plates, wherein the heat exchanger plates are provided with port openings forming inlet and outlet channels for the first and second fluids, wherein at least one of the first and second heat exchanger plates in a plate pair is arranged with a skirt extending at least partially around a first port opening to form a chamber between said skirt and a plate interspace, and wherein the chamber communicates with the first or second plate interspaces through a hole in one of the first and second heat exchanger plates of said plate pair, wherein
 the chamber is open to the channel through a gap between at least a free end portion of the skirt and an adjacent heat exchanger plate, and   the gap varies along a circumference of the channel and/or a cross section area of the chamber varies along the circumference of the channel.   
     
     
         2 . The brazed plate heat exchanger of  claim 1 , wherein the gap is smaller in a position closer to the hole and larger in a position remote from the hole. 
     
     
         3 . The brazed plate heat exchanger of  claim 1 , wherein the skirt is longer in a position closer to the hole and shorter in a position more remote from the hole. 
     
     
         4 . The brazed plate heat exchanger of  claim 1 , wherein an end portion of the skirt engages the adjacent heat exchanger plate and/or the next skirt in a position between the inlet channel and the chamber. 
     
     
         5 . The brazed plate heat exchanger of  claim 1 , wherein the skirt extends along at least 30% or at least 50% of the circumference of the first port opening. 
     
     
         6 . The brazed plate heat exchanger of  claim 1 , wherein the gap extends at least partially in the radial direction. 
     
     
         7 . The brazed plate heat exchanger of  claim 1 , wherein the first port opening of the first heat exchanger plate is smaller than the first port opening of the second heat exchanger plate. 
     
     
         8 . The brazed plate heat exchanger of  claim 1 , wherein the first port openings of the second heat exchanger plates are arranged eccentrically in relation to the first port openings of the first heat exchanger plates. 
     
     
         9 . The brazed plate heat exchanger of  claim 1 , wherein the cross section of the chamber is smaller in a position closer to the hole and larger in a position remote from the hole in a direction around the inlet channel. 
     
     
         10 . The brazed plate heat exchanger of  claim 1 , wherein the first heat exchanger plates are arranged with a first port opening area around the first port opening, and the second heat exchanger plates are arranged with a second port opening area around the first port opening, wherein the second port opening area is arranged with a different size than the first port openings area. 
     
     
         11 . The brazed plate heat exchanger of  claim 10 , wherein the first port opening area is bigger than the second port opening area. 
     
     
         12 . The brazed plate heat exchanger of  claim 10 , wherein the first port opening is arranged eccentrically in the first port opening area. 
     
     
         13 . The brazed plate heat exchanger of  claim 1 , wherein the first heat exchanger plate in a plate pair is provided with a first skirt at least partly surrounding the first port opening of the first heat exchanger plate, and the second heat exchanger plate in the plate pair is provided with a second skirt at least partly surrounding the first port opening of the second heat exchanger plate, and wherein a gap is arranged between a free end of the second skirt and a free end of the first skirt. 
     
     
         14 . The brazed plate heat exchanger of  claim 13 , wherein the second skirt is arranged radially outside the first skirt. 
     
     
         15 . The brazed plate heat exchanger of  claim 13 , wherein the free end of the second skirt radially displaced in relation to the free end of the first skirt. 
     
     
         16 . The brazed plate heat exchanger of  claim 13 , wherein the first and/or second skirts is/are arranged with varying length. 
     
     
         17 . The brazed plate heat exchanger of  claim 13 , wherein the first skirt and the second skirt extend at least partly in opposite axial directions. 
     
     
         18 . The brazed plate heat exchanger of  claim 13 , wherein the first port openings, the first skirts and the second skirts are formed with alternating projections and depressions around their circumferences. 
     
     
         19 . The brazed plate heat exchanger of  claim 18 , wherein the projections of the first skirts and the depressions of the second skirts are arranged alternatingly in the axial direction along the inlet channel formed thereby. 
     
     
         20 . The brazed plate heat exchanger of  claim 17 , wherein each of the first and second skirts comprises at least four projections and depressions. 
     
     
         21 . The brazed plate heat exchanger of  claim 17 , wherein the projections and depressions are distributed evenly along the entire skirt. 
     
     
         22 . The brazed plate heat exchanger of  claim 13 , wherein the free end of the first skirts are aligned in the axial direction with the free ends of the second skirts. 
     
     
         23 . The brazed plate heat exchanger of  claim 13 , wherein the gap is non-varying. 
     
     
         24 . The brazed plate heat exchanger of  claim 13 , wherein the first skirts and the second skirts are arranged with similar lengths.