Experimentation and Performance Analysis of Solar-Assisted Heat Pump Dryer for Intermittent Drying of Food Chips

A solar-assisted heat pump (HP) dryer is fabricated for intermittent drying. The experiment is performed for different intermittency ratios for radish drying using future refrigerant, R1234yf. The effect of total drying time (on-period + off-period) on various energetic, exergetic, and economic performances is investigated. Radish chips were dried to extract moisture from 92.4% to 11.9%. Energy efficiency and drying efficiency (DE) are estimated higher for a lower intermittency ratio. The moisture extraction rate (MER) and the specific moisture extraction rate (SMER) are higher for intermittent drying as compared with continuous drying and increase with a decrease in intermittency ratio. The economic analysis concludes that the payback period is lower for a lower intermittency ratio. The payback period for intermittency ratio of 1, 0.66, 0.33, and 0.2 are estimated as 1.617 years, 1.459 years, 1.384 years, and 1.347 years, respectively. Present experimental thermoeconomic analysis reveals that intermittent drying is much better (maximum enhancement of specific moisture extraction rate is 60.6%, that of energy efficiency is 56.4% and maximum reduction of drying cost is 37.9% with studied conditions) than continuous drying.