A tubular heat exchanger (10) comprising: a fluid circulation chamber (20) intended to be supplied with a first fluid, referred to as outer fluid, brought to a first temperature, a heat exchange matrix (30) housed in said circulation chamber and formed by a plurality of heat exchange tubes (31) each comprising at least one pair of ducts (32; 33) nested one inside the other, extending along a direction, referred to as longitudinal direction, and defining: a channel for circulating a fluid, referred to as inner channel (32c; 33c), suitable for being able to be supplied with a second fluid, referred to as inner fluid, brought to a second temperature, and a channel for the circulation of a fluid, referred to as intermediate channel (32d; 33d), and suitable for being able to be supplied with a third fluid, referred to as intermediate fluid, brought to a third temperature, different from said first temperature.

A tubular heat exchanger (10) comprising: a fluid circulation chamber (20) intended to be supplied with a first fluid, referred to as outer fluid, brought to a first temperature, a heat exchange matrix (30) housed in said circulation chamber and formed by a plurality of heat exchange tubes (31) each comprising at least one pair of ducts (32; 33) nested one inside the other, extending along a direction, referred to as longitudinal direction, and defining: a channel for circulating a fluid, referred to as inner channel (32c; 33c), suitable for being able to be supplied with a second fluid, referred to as inner fluid, brought to a second temperature, and a channel for the circulation of a fluid, referred to as intermediate channel (32d; 33d), and suitable for being able to be supplied with a third fluid, referred to as intermediate fluid, brought to a third temperature, different from said first temperature.

The purpose of the present invention is to provide a furnace wall in which a throat section with a smaller channel diameter than other regions can be formed using all peripheral wall tubes. Provided is a furnace wall comprising: a plurality of peripheral wall tubes (142), which are disposed so as to form a cylindrical shape when aligned in one direction and through the interior of which cooling water flows; and fins (140) that connect neighboring peripheral wall tubes (142) in an airtight manner. In a throat section in which the diameter of a horizontal cross-section of the cylindrical shape is reduced in comparison to other regions, the peripheral wall tubes (142) are disposed so as to be in mutual contact and the fins (140) are disposed on the inner circumferential sides of the cylindrical shapes.

The purpose of the present invention is to provide a furnace wall in which a throat section with a smaller channel diameter than other regions can be formed using all peripheral wall tubes. Provided is a furnace wall comprising: a plurality of peripheral wall tubes (142), which are disposed so as to form a cylindrical shape when aligned in one direction and through the interior of which cooling water flows; and fins (140) that connect neighboring peripheral wall tubes (142) in an airtight manner. In a throat section in which the diameter of a horizontal cross-section of the cylindrical shape is reduced in comparison to other regions, the peripheral wall tubes (142) are disposed so as to be in mutual contact and the fins (140) are disposed on the inner circumferential sides of the cylindrical shapes.