According to the flue gas characters of different calcium carbide furnace, ZG Boiler develops semi-closed internal combustion type calcium carbide waste heat boiler and full-closed direct combustion type calcium carbide waste heat boiler. In chemical industry, the waste heat boiler for semi-closed calcium carbide furnace produces steam for heating or power generation by burning the middle and low temperature flue gas of the calcium carbide; the direct-combustion waste heat boiler for full-closed calcium carbide furnace generates steam for heating or power generation by fueling the high temperature, combustible or ash flue gas heat.