Natural convection flows in parallel connected vertical channels with boiling

Abstract

The steady-state flow configuration in an array of parallel heated channels is examined with the objective of predicting the behavior of a reactor during a loss of flow accident. A method of combining the results of single tube experiments with a calculation scheme for the multiple tube array is developed. Only single ~single tube experiments were run. These are three possible flow solutions for a channel. They are as follows: gas and liquid flowing up, gas flowing up and liquid down, and both gas and liquid flowing down. This investigation eliminates the latter as a possible solution for a channel operating in an array of channels. For the two remaining flow cases the constraints of a common pressure drop across the channels and the satisfaction of continuity in the closed end plenum, determine a solution for each heat flux distribution over the array. The data in this investigation was obtained using Freon 113 as the coolant for an electrically heated glass tube. The data presented in not intended for use other than verification of the method of solution proposed. It is recommended that the coolant intended for use in the application be used with a prototype, rather than a model, channel in obtaining the single channel data.