Chemical　reaction　effect　is　a　critical　issue　in　the　heat　extraction　process　of　a　fractured　geothermal　reservoir.　In　this　study,　the　thermo-hydro-chemical　coupled　condition　is　simulated　based　on　a　unified　pipe-network　method　(UPM)　by　considering　interconnected　fracture　networks　embedded　in　the　rock　mass.　The　chemical　reaction　kinetics　of　silica　precipitation　and　dissolution　is　incorporated　to　capture　and　examine　the　effects　of　the　silica　water　interaction　on　the　evolution　of　fracture　apertures.　The　chemical　influenced　heat　transfer　between　solid　and　fluid　phases　in　the　fractured　porous　media　is　characterized　by　a　local　thermal　non-equilibrium　(LTNE)　model　introduced　based　on　two　energy　balance　equations.　A　pipe　equivalent　technique　is　used　to　discretize　the　multiphysical　coupled　equations　and　unify　the　fracture-matrix　information　at　the　interface　through　the　superposition　principle　in　the　UPM　framework.　Convergence　tests　are　performed　to　verify　the　proposed　model　with　one　large　fracture　embedded　in　a　doublet　system　for　geothermal　development.　Fracture　networks　are　then　introduced　in　a　case　study　where　the　influences　of　different　injection　temperature,　saturation　condition,　injection　pressure　differential　and　initial　fracture　aperture　on　the　silica　reaction　related　alteration　of　fracture　apertures　as　well　as　the　heat　production　are　analyzed.