This paper presents a simulation scheme of heat exchanger networks considering thermal and hydraulic effects simultaneously. The determination of network temperatures is carried out together with the evaluation of flow rates and pressures along the network, considering head losses in heat exchangers and associated piping. The model encompasses two systems of equations: a network hydraulic model, composed by a nonlinear system of mass balances and fluid flow equations, and an energy model, represented by a linear system of energy balances and heat exchanger equations. The mathematical structure is based on a matrix representation of the network. The proposed model allows a more realistic analysis of heat exchanger networks where flow rates are constrained by limitations of hydraulic facilities. The utilization of the simulation scheme is illustrated by the analysis of a cooling water system.