The advantages and disadvantages in structural features for two kinds of water-wall

namely water-wall with spiral pipe-rings

and water-wall with vertical pipe-rings boasting inner threads

for supercritical boilers

as well as thermal deviation during stage of pipe-blowing with stable pressure and during stage of various unit's load have been analysed and compared.Results show that the water-wall with spiral pipe-rings has better adaptability to the variation of unit's load and variation of fuel coal

but it has larger resistance

and vast amount of welding work

as well as the structure of system being complex;the water-wall with vertical pipe-rings boasting inner treads has small resistance

and has little amount of welding work in installation

the structure of supports and rigid beams being simple

but it is sensitive to heat absorption.With regrad to the two kinds of water-wall

each has its own features

during the time of design

they can be analysed and selected according to the concrete situations.