Energy-exergy and environ-economic (4E) analysis while drying ivy gourd in a passive indirect solar dryer without and with energy storage system and results comparison

Abstract

The energy-exergy and environ-economic (4E) analysis was conducted while drying ivy gourd in a natural convection indirect solar dryer (ISD) without and with a thermal energy storage system (TESS). The initial setup was modified with TESS by integrating a rectangular glass box holding polycarbonate tubes filled with paraffin wax. The paraffin wax was selected based on its easy availability in the market, and also the existing studies suggested that it works successfully by shortening the drying time, homogenizing the process and maintaining temperature. Mass loss, air velocity, and temperature data were recorded during experiments in both setups. The average collector and drying efficiencies of ISD were 62.56 and 61.87 (without and with TESS) and 6.62% and 13.13% (without and with TESS), respectively. The specific energy consumptions were 1.549 and 0.253 kWh/kg for without and with TESS, respectively. The exergy parameters for collector and drying cabinet such as average exergy efficiency, loss, outflow, and inflow without and with TESS were estimated. Other exergy parameters such as the ratio of waste exergy, improvement potential, sustainability index and environmental impact factor were estimated and compared for both setups. CO2 mitigation and credit were better with the TESS setup. The energy payback period of the dryer was 1.04 and 1.51 years for without and with TESS setups for a lifespan of 25 years. Comparatively, with TESS setup performed well in all the evaluated parameters.