Experiment on waste heat recovery-assisted heat pump drying of food chips: Performance, economic, and exergoeconomic analyses

Abstract

Novel waste heat recovery-assisted heat pump dryer is designed, developed, and experimented in different operating modes. Energy, exergy, economic, and exergoeconomic parameters of the dryer with and without waste heat recovery are experimentally compared. Radish chips are dried to remove moisture from 93.5% to 10.5% at fixed dryer inlet air velocity. Both energy and exergy efficiencies are found highest for the waste heat recovery-assisted (hybrid) system (56.26% and 35.9%, respectively). Specific moisture extraction rate (2.4 kg/kWh) and coefficient of performance (6.72) are highest for the hybrid system. The payback period for the hybrid system over the simple system is 33 months. The lowest exergoeconomic factor is for expansion devices in both simple and hybrid systems (0.0918 and 0.1348, respectively). Total exergy destruction costs for simple and hybrid systems are 0.10148 and 0.1266 $/h, respectively. The most important component that needs to improve based on the exergoeconomic factor is the drying chamber. Practical applications: In the present study, a novel heat pump dryer assisted with waste heat recovery from the diesel engine is designed and developed. Various energy, exergy, economic, and exergoeconomic performance parameters with and without waste heat recovery are experimentally compared. To check the applicability, the radish chips have been dried to remove moisture from 93.5% to 10.5% at fixed dryer inlet air velocity. The testing shows that the proposed system is superior as compared to the simple heat pump dryer in terms of both energy and exergy efficiencies, specific moisture extraction rate, and overall heating coefficient of performance. The payback period for the proposed system over a simple one is found 3 years approximately. The proposed system can be a futuristic and promising solution for the drying applications, which satisfies two purposes: An effective way to utilize the engine waste heat and superior system performance. © 2020 Wiley Periodicals LLC.