US Patent 11397052 Heat exchanger

A heat exchanger includes: a hollow pillar shaped honeycomb structure; a first cylindrical member fitted to a surface of an outer peripheral wall of the pillar shaped honeycomb structure; a second cylindrical member fitted to a surface of an inner peripheral wall of the pillar shaped honeycomb structure; a cylindrical guide member having a portion, the portion being disposed on a radially inner side of the second cylindrical member with a distance so as to form the flow path for the first fluid;