Research methods: Combining with relative specifications and taking severe cold area mountain tunnel in Neimeng province for example，this paper analyses the technic and economic feature about electric tracer heating system，water release thermal retardation system and dry type hydrant system.
Research results: This paper gives the consists of electric tracer heating system, water release thermal retardation system and dry type hydrant systems, premie preference and methods of calculation.
Research conclusions: Electric tracer heating system, water release thermal retardation system and dry type hydrant systems are all feasible in function. Cost of the electric tracer heating system is higher; water release thermal retardation system is the most economic system; dry type hydrant system must be qualified by fire fighting department. And it depends on the specific engineering to choose the system.
2007, Vol. 24 
