Experimental investigations on steady state natural circulation behavior of multiple parallel boiling channel system

In some industrial applications, including nuclear power plants, natural circulation flow is often employed as a reliable heat transport method. A common characteristic of many industrial two-phase natural circulation systems is the presence of a large number of parallel boiling channels. Sensitivity of the steady state behavior of such a two-phase natural circulation system to different system parameters has many implications vis-à-vis performance of the system as per the design intent under various operating conditions. This article reports the results of experimental studies carried out on the characteristics of a low pressure two-phase natural circulation system with parallel boiling channels having their individual heat sources. The work covers the study of dependence of system behavior on operational history, down-comer resistance and channel power. In view of its particular significance in nuclear industry, a special system condition with zero power in one of the parallel channels was also studied. An experimental setup consisting of 10 transparent parallel channels was designed and constructed for conducting these experimental investigations.