A heat exchanger plate for a plate heat exchanger (12) includes a first side, a second side and a center point (P) through which an imaginary center axis (A) extends in a direction perpendicular to a plane of the plate. The plate comprises a first port for a first medium, and at least a second port and a third port for a second medium. The plate further comprises a first sealing arranged on the second side around the first port, a second sealing arranged on the second side at a circumference of the plate, and a closed third sealing arranged between the first and second sealings to form a first heat transfer area and a second heat transfer area separated from the first heat transfer area. The second port is arranged in the first heat transfer area and the third port is arranged in the second heat transfer area.

Process for heating via oxy-fuel combustion in which a stream of air is heated by means of at least one portion of the residual heat present in the fuel gases discharged from the combustion chamber, at least one portion of said hot air stream is introduced into an oxygen production unit in which a portion of the oxygen present in the hot air stream is extracted by means of one or more ITM, with a first stream of oxygen at high temperature being obtained, said first stream of oxygen is mixed with a second stream of oxygen so as to obtain a total stream of oxygen at a lower temperature than that of the first stream of oxygen, at least one portion of the total stream of oxygen being transported to the combustion chamber and used within as oxygen-rich oxidizer.

Process for heating via oxy-fuel combustion in which a stream of air is heated by means of at least one portion of the residual heat present in the fuel gases discharged from the combustion chamber, at least one portion of said hot air stream is introduced into an oxygen production unit in which a portion of the oxygen present in the hot air stream is extracted by means of one or more ITM, with a first stream of oxygen at high temperature being obtained, said first stream of oxygen is mixed with a second stream of oxygen so as to obtain a total stream of oxygen at a lower temperature than that of the first stream of oxygen, at least one portion of the total stream of oxygen being transported to the combustion chamber and used within as oxygen-rich oxidizer.

A radiative recuperator preheats oxidant and/or fuel for combustion at one or more burners of a furnace. The recuperator includes a duct, at least portions of which comprise a material having a thermal conductivity of greater than 1 W/(m.Math.K), preferably greater than 3 W/(m.Math.K), that receives hot flue gas produced by the burner(s). The duct radiatively transfers heat to oxidant or fuel (for preheating) flowing through one or more metallic pipes disposed in between the duct and an insulating wall.

A radiative recuperator preheats oxidant and/or fuel for combustion at one or more burners of a furnace. The recuperator includes a duct, at least portions of which comprise a material having a thermal conductivity of greater than 1 W/(m.Math.K), preferably greater than 3 W/(m.Math.K), that receives hot flue gas produced by the burner(s). The duct radiatively transfers heat to oxidant or fuel (for preheating) flowing through one or more metallic pipes disposed in between the duct and an insulating wall.

To improve the efficiency of recuperator burners, preferably to over 80%, a recuperator burner (10) is equipped with an auxiliary heat exchanger (26) which surrounds the recuperator (22), wherein both the recuperator and the auxiliary heat exchanger are preferably formed as purely counterdirectional-flow heat exchangers, wherein the auxiliary heat exchanger (26) has the air supplied to it on the side facing toward the furnace wall (11). The housing (15) around the auxiliary heat exchanger (26) can be cooled with cool air from the inside. In one configuration, the air is initially conducted to a flange cooler (45) to protect the region of the flange (16) against the exhaust-gas temperature. For example, the ceramic recuperator pipe (26) is resiliently pressed, and sealed off, against an outlet-side surface (35) of the auxiliary heat exchanger (26), which preferably has gap-like air ducts (39) formed in flattened pipes (40).

To improve the efficiency of recuperator burners, preferably to over 80%, a recuperator burner (10) is equipped with an auxiliary heat exchanger (26) which surrounds the recuperator (22), wherein both the recuperator and the auxiliary heat exchanger are preferably formed as purely counterdirectional-flow heat exchangers, wherein the auxiliary heat exchanger (26) has the air supplied to it on the side facing toward the furnace wall (11). The housing (15) around the auxiliary heat exchanger (26) can be cooled with cool air from the inside. In one configuration, the air is initially conducted to a flange cooler (45) to protect the region of the flange (16) against the exhaust-gas temperature. For example, the ceramic recuperator pipe (26) is resiliently pressed, and sealed off, against an outlet-side surface (35) of the auxiliary heat exchanger (26), which preferably has gap-like air ducts (39) formed in flattened pipes (40).

Recuperator burner including a recuperator, which has two separate flow systems provided for guiding counter-flowing fluids, each system including at least one flow channel being open on both sides, and the at least two fluids entering/leaving via intake inputs and offtake outputs at opposite ends of the burner inlet and burner outlet, and one of the fluids is set up by a combustion air to be preheated and the other by an exhaust gas of the burner, wherein the recuperator accommodates the two flow systems in a heat transfer body which is made of one piece and whose jacket-shaped outer wall section at the burner inlet defines a flow pot including said input and output integrally attached.

Recuperator burner including a recuperator, which has two separate flow systems provided for guiding counter-flowing fluids, each system including at least one flow channel being open on both sides, and the at least two fluids entering/leaving via intake inputs and offtake outputs at opposite ends of the burner inlet and burner outlet, and one of the fluids is set up by a combustion air to be preheated and the other by an exhaust gas of the burner, wherein the recuperator accommodates the two flow systems in a heat transfer body which is made of one piece and whose jacket-shaped outer wall section at the burner inlet defines a flow pot including said input and output integrally attached.

The present disclosure provides a method and a system for denitrogenation combustion and CO.sub.2 capture and utilization in a gas boiler. The method is implemented by the system for denitrogenation combustion and CO.sub.2 capture and utilization in the gas boiler, and comprises: after circulating flue gas is discharged from a gas boiler, introducing the circulating flue gas into a gas heat exchanger to perform heat exchange with natural gas, hydrogen, and carbon-based denitrogenation gas; introducing the circulating flue gas after heat exchange into a flue gas dehydration device to perform dehydration; introducing a first portion of the circulating flue gas after the heat exchange and dehydration into a blower through the flue gas dehydration device to be pressurized by the blower and introduced into a carbon-based denitrogenation gas mixer; preparing the carbon-based denitrogenation gas by mixing oxygen and the circulating flue gas using the carbon-based denitrogenation gas mixer for combustion for the gas boiler; and introducing a second portion of the circulating flue gas after heat exchange and dehydration into a CO.sub.2 recovery device to perform purification and deoxygenation through the flue gas dehydration device to obtain a CO.sub.2 product, and pressurizing and transmitting the CO.sub.2 product to a CO.sub.2 utilization device through a CO.sub.2 compressor.