The invention relates to a multi-
combustion type civil
heating furnace integrating a direct firing, a return firing and a gasified
combustion. The
heating furnace comprises a furnace body and an
expansion tank, a coaling port, a front
air door and a
slag-removing door are sequentially arranged on a front end of the furnace body from top to bottom, and a first furnace port is arranged on an upper end of the furnace body. The
heating furnace is characterized in that a second furnace port is arranged on an upper end of the first furnace port, a porous cylindrical inner sandwich layer
combustion-aiding device is embedded in the first furnace port, a cylindrical temperature increasing device with high
refractory is fixedly arranged on a lower end of the porous cylindrical inner sandwich layer combustion-aiding device, an inner air duct
system is arranged in the furnace body, and a connecting-rod-type
air door adjustment device is arranged on a rear end of the furnace body. The heating furnace has the positive effects that firstly, the environmental
pollution is reduced, secondly, the energy is saved, thirdly, the heat efficiency is high, fourthly, the use is safe, fifthly, multiple functions of one furnace are realized, and the requirement on use for a user is met, and sixthly, the combustion
controllability of fuels and the fire banking capability of a
cooker unit are increased.