The low-nitrogen emission gas condensing steam boiler is a three-way wet back fuel (gas) boiler designed by our group company with German technology and designed according to domestic and foreign advanced technology and experience. The boiler is operated automatically, and after the fuel is atomized by the burner, the torch formed is filled in the full-wave furnace and transmits the radiation heat through the wall of the furnace, which is the first return stroke. The high-temperature flue gas generated by the combustion converges in the back-combustion chamber, and turns into the second return stroke, that is, the spiral smoke tube bundle region. After the convective heat exchange, the flue gas temperature 驢 gradually decreases to the front smoke box, and then turns to the third return trip. That is, the light pipe bundle area, and then the smoke box flows into the chimney and finally into the atmosphere. The series of products are safe, reliable, high efficiency, energy saving and environmental protection, easy to maintain, durable, fully automatic intelligent control, etc.; all of them have passed the energy efficiency test of the special inspection institute thermal energy test center, and all performance indicators are higher than the design requirements. Advanced level at home and abroad.