Gas heat exchanger and SCR denitration mixed flow system

The utility model relates to a gas heat exchanger, including the heat transfer bank of tubes, the heat exchange tube of the heat transfer bank of tubes forms cold air duct, the intervascular clearanceformation heat flue gas passageway of heat transfer of the heat transfer bank of tubes, be equipped with the vortex fin on the heat exchange tube, still including entry heat transfer case and exportheat transfer case, the both ends of the heat transfer bank of tubes feed through respectively entry heat transfer case with export heat transfer case. The utility model discloses still relate to a SCR denitration mixed flow system, including ammonia injection grid gentleness gas heat exchanger, ammonia injection grid sets up in the flue just perpendicularly with the flue gas direction, gas heat exchanger is located the ammonia injection grid rear still includes ammonia air mixer and dilutes the fan, it is used for providing the reaction required cold air to dilute the fan, ammonia air mixer is used for ammonia and air