Abstract: In the field of heat pump drying, air source heat pump technology is often used to dry various materials. The technology of drying fire hoses using air source heat pump is gradually mature, but there are still problems such as low drying efficiency, long drying time, and difficult to dry thoroughly. In order to solve the problem of high humidity of circulating air in the later stage of heat pump drying, and improve the drying efficiency of fire hoses, Specific Moisture Extraction Rates （SMER） and Moisture Extraction Rates （MER）, a heat pump-infrared ray combined drying device was designed and developed, and the Design expert software was used to verify and determine the best working conditions suitable for fire hose drying. The experimental results show that the total power consumption of the system is 6.57 kWh, SMER is 1.32 kg/kWh, and MER is 2.91 kg/h when the infrared radiation temperature is 36 ℃, the conversion time from the heat pump to infrared ray is 1.6 h, and the fan air supply speed is 2.2 m/s. Compared with the traditional heat pump drying hose technology, the total power consumption is basically unchanged, the value of SMER is increased by 58.3%, the value of MER is increased by 61.6%, and the comprehensive drying effect is significantly improved.

Key words: infrared drying, combined drying, Design expert, fire hose, response surface method