Comparative study of without and with heat storage while drying bitter gourd slices in a forced convection indirect type solar dryer

Drying is a vigorous, energy-consuming process, so practice with solar energy is a suitable option. The usage of a blower, known as forced convection, which is operated by solar energy, again enhances the system performance. This work analyses the drying of bitter gourd pieces in a forced convection indirect type solar dryer without and with a thermal energy storage (TES) facility (case-1 and case-2). The case-1 dryer consists of CPU (central processing unit) fans operated by solar photovoltaic cells, a solar air collector, and a drying section. The case-2 setup consists of the same components as case-1 along with a TES device. Drying, thermal, and performance parameters were determined for both cases, and the results were compared. In case-1, the range of collector efficiency was found to be 40.43–66.19%, while in case-2, it was 50.25–63.34%. The average dryer efficiency in case-1 and case-2 was noticed to be 8.48% and 12.29%, respectively, which is 44.92% greater in case-2. Also, the drying could be finished in a day in case-2. 6.41%, 8.33%, 8.61%, and 81.13% improvements are noticed in drying rate, mass and heat transfer coefficients, and specific moisture extraction rate, respectively, in case-2 setup.