Neslihan Colak

A Comparative Study on Exergetic Performance Assessment for Drying of Broccoli Florets in Three Different Drying Systems

This article deals with the exergy analysis and evaluation of broccoli in three different drying systems. The effects of drying air temperature on the exergy destruction, exergy efficiency, and exergetic improvement potential of the drying process were investigated. The exergy destruction rate for the drying chamber increased with the rise in the drying air temperature at 1.5 m/s, both in the tray and the heat pump dryer. The highest exergy efficiency value was obtained as 90.86% in the fluid bed dryer in comparison to the other two drying systems and the improvement potential rate was the highest in the heat pump dryer during drying of broccoli at the drying air temperature of 45°C and the drying air velocity of 1.0 m/s.

Exergoeconomic analysis of plum drying in a heat pump conveyor dryer.

In this study, plum slices were dried in a heat pump dryer designed and constructed in Ege University, Izmir, Turkey. Drying experiments were carried out at an air temperature range of 45–55°C. The performance of the dryer along with its main components were evaluated using an exergy analysis method. Exergy destruction and capital cost rates were used for the exergoeconomic analysis, which is based on the quantities exergy, cost, energy, and mass (EXCEM) method. Exergy destruction rates to capital cost values R ex were obtained to vary between 1.668 and 2.063 W/USD at different drying air temperatures. R en values were observed to range from 6.258 to 5.749 W/USD. R en values decreased as the drying air temperature increased, contrary to R ex values. and values increased linearly with increasing temperature due to the loss, whereas decreased due to the relatively higher energy utilization efficiency of the heat pump. In the compressor, and values decreased with the increase in the temperature contrary to the other components. had the lowest value in the drying duct. However, in the compressor, expansion valve, and heat recovery, values were found to be higher and should be improved in these units.

An exergetic performance assessment of three different food driers

Abstract In this study, plum slices were dried in three different driers (tray, fluid bed, and heat pump (HP) driers). Drying experiments were carried out at an air temperature range of 45-55 °C with an air velocity of 1.5 m/s. The performance of the driers along with their main components was evaluated and compared by using the exergy analysis method. The most important component for improving the system efficiency was determined to be the fan—heater combination for both the tray and fluid bed driers, and the motor—compressor assembly for the HP drier. The exergy loss and flow diagram (the so-called Grassmann diagram) of the driers was also presented to give quantitative information regarding the proportion of the exergy input dissipated in the various system components. Effects of the drying air temperature on the performance of the drying process were discussed. The highest exergetic efficiency values were obtained to range from 72.72 to 75.66 per cent for the HP drier, followed by the tray and fluid bed driers varying between 37.94 and 39.46 per cent, and between 22.83 and 24.07 per cent, respectively.

Performance investigation of the drying of parsley in a tray dryer system

The performance of a tray dryer system for the parsley drying process was assessed using energy and exergy analysis methods in this study. The drying temperature ranged from 40°C to 60°C, while the drying air velocity varied from 0.5 m/s to 1.5 m/s. The higher temperature and lower velocity led to higher exergy and energy efficiencies. The exergy efficiency value for the overall system on a product/fuel basis was found to be 3.62%. The values for Specific Moisture Extraction Rate (SMER) and Specific Moisture Exergetic index (SMExR) were obtained to be 0.08 and 2.47 kg/kWh, respectively.