一、前言干燥作业的能耗在工业总能耗中占有很大比重。据英国1978年在食品等六个主要工业部门统计,干燥用能占总能耗10%以上,参见表1。以往,干燥作业仅考虑干燥物的工艺要求,能源利用率极低。而在干燥作业中,采用一般的气—气热交器回收废热,效果是很有限的。若用热泵技术回收干燥窑排出废气的热量,可以大幅度提高能源利用率,因而 I. Preface The energy consumption of dry operation occupies a large proportion of the total industrial energy consumption. According to the statistics of the six main industrial sectors such as foodstuffs in Britain in 1978, the energy consumption for drying accounts for more than 10% of the total energy consumption, as shown in Table 1. In the past, the drying operation only considered the drying process requirements, low energy efficiency. In the drying operation, the use of general gas - gas heat collector recycling waste heat, the effect is very limited. If the use of heat pump technology to recover kiln exhaust heat, can significantly improve energy efficiency, and thus