热泵型干燥室气流组织综述

在过去的十年中,由于对干燥农产品的高需求,在全球范围内引发了高密度热泵型干燥技术快速扩张. 干燥室内物料的干燥速率与气流分布有很大的关系,已提出了多种配置和方法来提高干燥室内的气流分布. 阐述了热泵干燥系统的运行原理和特点,分别从干燥室内部结构、工况设计、节能形式三大方面对国内外相关研究和案例进行综述. 指出了干燥室内气流分布不均匀是造成物料干燥效率低、不均匀和品质差的主要原因,分析了各种空气管理的办法,包括采用不同的送回风方式可避免干燥室内部形成回流,应用优化的几何结构可减小流体流动过程中的阻力,提高热泵干燥室内的综合性能. 指出需要进一步探索如何合理设计排湿口位置并对应设计不同的管道布置,以改善干燥室内热量及湿度的合理分布.

Airflow Organization and Managementin Heat Pump Dryer:a Review

Over the past decade,high demand for dried agricultural products has led to a rapid expansion of high density heat pump drying technology worldwide.The drying rate of materials in the drying room is closely related to the distribution and management of air flow.In this paper,the operating principle and characteristics of heat pump drying system are described,and the domestic and foreign researches are summarized from three aspects,namely,interior structure,working condition design and energy-saving form. The paper points out that the dry indoor airflow uneven distribution is the main cause of the low drying efficiency poor quality,and analyzes the various air management approaches,including that different way of back to the wind can avoid dry indoor form circumfluence,and optimized geometric structure can reduce the resistance in the process of fluid flow. Thus,the comprehensive performance of heat pump drying chamber can be improved. In view of the lack of research on dehumidification method in drying chamber,further research is needed on how to reasonably design the location of dehumidification outlet and the corresponding design of different pipeline layout,so as to improve the reasonable distribution of heat and humidity in drying chamber.