基于喷气增焓技术的谷物干燥机热泵装置设计与试验

Design and Test of Grain Dryer Heat Pump Based on Vapor Injection Technology

为拓展热泵的使用范围,提高热泵系统的适用范围和年利用率,设计了带喷气增焓装置的空气源热泵机组,通过3组不同功率热泵间的有机组合,提高了热泵系统在低温环境下的能效比。试验结果显示,当环境温度为-5℃时,采用喷气增焓可使热泵机组送风温度、制热系数分别由40℃、2.21提高到45℃、2.33。证实了喷气增焓技术的有效性,热泵干燥系统可满足循环式谷物干燥机在不同环境条件下的作业要求。

In order to expand the working range of heat pump and improve the applicable range and annual utilization rate of heat pump system,an air source heat pump unit with vapor injection technology was designed.The heat recovery device was used to recover the waste heat from the dryer exhaust gas to preheat the fresh air.The heat pump unit consisted of three sets of heat pumps with different powers.The heat pump unit's start-stop combination adapted to different process requirements and environmental conditions,heat pump can improve the annual energy efficiency ratio by this way,and the enhanced vapor injection technology improved the performance of the heat pump system in low temperature environment.The designed heat pump unit was tested.When the ambient temperature was-5℃,the air supply temperature of the heat pump was 40℃and the COP of the heat pump was 2.21,the air supply temperature of the heat pump used enhanced vapor injection was 45℃and the COP of the heat pump used enhanced vapor injection was 2.33.The experimental results showed that the validity of vapor injection technology and the designed heat pump can meet the operating requirements of recirculation drier under different environmental conditions.This study was of great practical significance for the development of green and energy-saving drying process equipment system.The results showed that the heat pump dryer can be applied to rice and wheat drying operations in the Jianghuai region.