[11] [11] LIU S C, LI X Q, SONG M J, et al. Experimental investigation on drying performance of an existed enclosed fixed frequency air source heat pump drying system[J]. Applied Thermal Engineering, 2018, 130:735-744.

[14] [14] REN Y, CHEN Z, WU W, et al. Study on the effect of circulating air volume on the performance of closed loop heat pump drying system[J]. Applied Thermal Engineering, 2022, 210: 118362.

[15] [15] YOUSAF K, LIU H, GAO X, et al. Influence of environmental conditions on drying efficiency and heat pump performance in closed and open loop drying of paddy[J]. Drying Technology, 2020, 38(16): 2217-2230.

[17] [17] BANTLE M, KVALSVIK K H, TOLSTOREBROV I. Performance simulation of a heat pump drying system using R744 as refrigerant[C]// Proceedings of the 12th IIR Gustav Lorentzen Conference on Natural Refrigerants. Edinburgh: IIF-IIR, IoR, 2016.

[18] [18] WANG Y, LI M, QIU Y, et al. Performance analysis of a secondary heat recovery solar-assisted heat pump drying system for mango[J]. Energy Exploration and Exploitation, 2019, 37(4): 1377-1387.

[19] [19] LI W, SHENG W, ZHANG Z, et al. Experiment on performance of corn drying system with combination of heat pipe and multi-stage series heat pump equipment[J]. Transactions of the Chinese Society of Agricultural Engineering, 2018, 34(4): 278-284.

[22] [22] MOHAMMADI I, TABATABAEKOLOOR R, MOTEVALI A. Effect of air recirculation and heat pump on mass transfer and energy parameters in drying of kiwifruit slices[J]. Energy, 2019, 170: 149-158.