Abstract:The temperature transfer matrix equations for threefluid separate type heat pipe heat exchangers with the same and different heat transfer area in each heat pipe row are obtained by establishing an analytical heat transfer model in the cocurrentor countercurrentflow mode. Using the temperature transfer matrix equations of exchanger with the each row heat transfer area is similar. The relationships of heat exchanger effectiveness θ1, θ2 with M, NTU, U, Δti are derived in the cocurrentor countercurrentflow mode. For the designing and checking calculation of the heat recovery device for the large hot blast stove in steel plant, the theoretical results can be used and it is proved correct in practical application.