Supply and extraction of tube flows at intermediate temperature in helically coiled heat exchangers

Abstract

A heat exchanger for the indirect exchange of heat between a first fluid and a second fluid, the heat exchanger having a casing surrounding a casing chamber that accommodates the first fluid. A core tube may extend within the casing. A tube bundle is arranged in the casing chamber and has multiple tubes to accommodate the second fluid. The tubes are helically wound around a longitudinal axis of the chamber or around the core tube in a coil region extending from a lower coil end to an upper coil end. At least one tube is coiled only in a section of the coil region. Outside of the section of the coil region the at least one tube extends as a straight tube to the lower coil end, the upper coil end, or to both the lower coil end and the upper coil end.

1 . A heat exchanger for the indirect exchange of heat between a first fluid and a second fluid, the heat exchanger comprising:
 a casing extending along a longitudinal axis and surrounding a casing chamber, the casing chamber for accommodating the first fluid;   a tube bundle arranged in the casing chamber, the tube bundle having multiple tubes for accommodating the second fluid;   wherein in a coil region extending along the longitudinal axis, the tubes of the tube bundle are helically coiled around the longitudinal axis from a lower coil end to an upper coil end;   wherein at least one tube of the tube bundle is coiled around the longitudinal axis in only a section of the coil region; and   wherein the at least one tube extends as a straight tube below the section of the coil region along the longitudinal axis to the lower coil end; or   wherein the at least one tube extends as a straight tube above the section of the coil region along the longitudinal axis to the upper coil end; or   wherein the at least one tube extends as a straight tube below the section of the coil region along the longitudinal axis to the lower coil end and as a straight tube above the section of the coil region along the longitudinal axis to the upper coil end.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein the heat exchanger has a core tube that extends along the longitudinal axis within the casing; and
 wherein the tubes of the tube bundle are helically coiled around the core tube in the coil region.   
     
     
         3 . The heat exchanger according to  claim 1 , wherein the section of the coil region is positioned along the longitudinal axis such that, during operation of the heat exchanger a temperature prevails in the section of the coil region that is lower than a temperature prevailing at the lower coil end and that is higher than a temperature prevailing at the upper coil end. 
     
     
         4 . The heat exchanger according to  claim 1 , wherein the at least one tube of the tube bundle comprises multiple tubes. 
     
     
         5 . The heat exchanger according to  claim 4 , wherein the multiple tubes are coiled in multiple layers around the longitudinal axis. 
     
     
         6 . The heat exchanger according to  claim 1 , wherein multiple tube bundles are arranged in the casing chamber.