This paper proposes a single stage/cascade double mode heat pump drying system, which can adapt to the temperature variation of environment and then satisfy the drying system's heating demand. Meanwhile the maximum temperature of drying air can be elevated using cyclic heating. Moreover, a prototype of the single stage/cascade double mode heat pump is developed and an experimental study is carried out. On the basis of experimental results, the performance variation of the heat pump at different modes and operating condition is analyzed. According to the results, it can be concluded that the maximum drying air temperature of cascade mode is higher than that of single stage with the same environment temperature and its difference decreased with the environment temperature. At the same environment temperature, both the heating capacity and power consumption of cascade mode are larger than single stage and the difference of power consumption increased with the environment temperature. With the increase of environment temperature, there existed a maximum COP of cascade mode and the COP of single stage kept increasing. The pressure ratio of the high stage compressor varied greatly at different operating mode and its selection should be reasonable.
SHEN Jiubing
,
GUO Ting
,
WU Xiaokun
,
CHEN Wenqing
. Design and Experimental Study of a Heat Pump Dryer with Dual Models of Single Stage and Cascade Cycles[J]. Journal of Mechanical Engineering, 2018
, 54(10)
: 218
-224
.
DOI: 10.3901/JME.2018.10.218
[1] MINEA V. Drying heat pumps - Part Ⅱ:Agro-food, biological and wood products[J]. International Journal of Refrigeration, 2013, 36(3):659-673.
[2] 刘贵珊, 何建国, 韩小珍, 等. 热泵干燥技术的应用现状与发展展望[J]. 农业科学研究, 2006, 27(01):46-49. LIU Guishan, HE Jianguo, HAN Xiaozhen, et al. Application situation and development prospect of drying by heat pump[J]. Journal of Agricultural Sciences, 2006, 27(01):46-49.
[3] KIM M, KIM M S, KIM Y. Experimental study on the performance of a heat pump system with refrigerant mixtures' composition change[J]. Energy, 2004, 29(7):1053-1068.
[4] COMAKLI K, SIMSEK F, COMAKLI O, et al. Determination of optimum working conditions R22 and R404A refrigerant mixtures in heat-pumps using Taguchi method[J]. Applied Energy, 2009, 86(11):2451-2458.
[5] CHUA K, CHOU S. A modular approach to study the performance of a two-stage heat pump system for drying[J]. Applied Thermal Engineering, 2005, 25(8):1363-1379.
[6] 马利敏, 王怀信, 王继霄.一种高温热泵工质的理论与试验性能[J]. 机械工程学报,2010,46(12):142-147. MA Limin,WANG Huaixin,WANG Jixiao. Theoretical and experimental cycle performances of working fluid for high temperature heat pumps[J]. Journal of Mechanical Engineering, 2010, 46(12):142-147.
[7] 沈九兵, 王瑞鑫, 周明龙, 等. 半封闭螺杆制冷压缩机排气噪声模拟与试验研究[J]. 机械工程学报,2017,53(20):169-175. SHEN Jiubing, WANG Ruixin, ZHOU Minglong, et al. Numerical and experimental research on the discharge noise of twin-screw refrigeration compressors[J]. Journal of Mechanical Engineering,2017,53(20):169-175.
[8] SAENSABAI P, PRASERTSAN S. Effects of component arrangement and ambient and drying conditions on the performance of heat pump dryers[J]. Drying Technology, 2003, 21(1):103-127.
[9] TOAL R, MORGAN R, MCMULLAN J. Experimental studies of low-temperature drying by dehumidification. Part 2-Experimental[J]. International Journal of Energy Research, 1988, 12(2):315-344.
[10] PETER Y. Design and test of a solar-dehumidifier kiln with storage and heat recovery system[J]. Forrest P, 2007, 37(5):25.
[11] 杜垲, 徐锡斌.空气回热闭式热泵干燥系统实验研究[J]. 太阳能学报, 1998, 19(4):429-432. DU Kai, XU Xibin. Experimental studies on heat pump drying system with heat recovery exchanger[J]. Acta Energiae Solaris Sinica, 1998, 19(4):429-432.
[12] 张宇凯. 热泵干燥机控制系统的研究[D]. 南京:南京农业大学, 2004. ZHANG Yukai. Research on the control system of heat pump dryer[D]. Nanjing:Nanjing Agricultural University, 2004.
[13] ZYLLA R, ABBAS S, TAI K, et al. The potential for heat pumps in drying and dehumidification systems I:Theoretical considerations[J]. International Journal of Energy Research, 1982, 6(4):305-322.
[14] TAI K, ZYLLA R, DEVOTTA S, et al. The potential for heat pumps in drying and dehumidification systems Ⅱ:an experimental assessment of the heat pump characteristics of a heat pump dehumidification system using R114[J]. International Journal of Energy Research, 1982, 6(4):323-331.
[15] CARRINGTON C, BAINES P. Second law limits in convective heat pump driers[J]. International Journal of Energy Research, 1988, 12(3):481-494.
[16] CEYLAN İ, AKTAS M, DOGAN H. Energy and exergy analysis of timber dryer assisted heat pump[J]. Applied Thermal Engineering, 2007, 27(1):216-222.
[17] 张振涛. 两级压缩高温热泵干燥木材的研究[D]. 南京:南京林业大学, 2008. ZHANG Zhentao. Research on woods drying by high temperature heat pump with two stage compressing[D]. Nanjing:Nanjing Agricultural University, 2008.
[18] 刘永忠, 杨丽坤, 孙皓, 等. 复叠式与二级压缩式热泵冷冻干燥系统循环特性比较[J]. 真空与低温, 2004, 10(2):29-33. LIU Yongzhong, YANG Likun, SUN Hao, et al. Comparison on performances of cascade heat pump and two-stage compression heat pump for freeze-dryer[J]. Vacuum &Cryogenics, 2004, 10(2):29-33.
[19] 赵力, 丁国良. 地热热泵系统负荷调节的理论与试验分析[J]. 机械工程学报, 2002, 38(8):100-104. ZHAO Li, DING Guoliang. Theory and experiment evaluation about load adjustment of geothermal heat pump system[J]. Journal of Mechanical Engineering, 2002, 38(8):100-104.
[20] QU Minglu, FAN Yanan, CHEN Jianbo, et al. Experimental study of a control strategy for a cascade air source heat pump water heater[J]. Applied Thermal Engineering, 2017, 110:835-843.
