Low-heating-value gas burner

The utility model discloses a low-calorific-value gas burner which comprises an outer shell, the inner portion of the outer shell is axially divided into a gas chamber and a stable combustion chamber, and the outer shell is provided with a conical outer mixing section with a reduced caliber. The fuel gas chamber comprises a fuel gas inner pipe and a fuel gas outer pipe which are coaxially arranged in a sleeved mode, an annular combustion-supporting air flow channel is formed between the fuel gas outer pipe and the outer shell, an annular fuel gas flow channel is formed between the fuel gas inner pipe and the fuel gas outer pipe, a first rotational flow blade assembly is annularly arranged at the rear end of the fuel gas flow channel, and a fuel gas combustion-supporting device is arranged in the fuel gas inner pipe. The rear end of the stable combustion chamber is located in the outer mixing section, the stable combustion chamber comprises a stable combustion inner pipe and a stable combustion outer pipe whic