Abstract: Heat pump drying equipment is a new type of fire hose drying equipment, in order to solve the problem of large energy waste of heat pump drying equipment, a fire hose heat pump drying equipment with bypass exhaust based on air source heat pump has been developed. In order to evaluate the influence of bypass and exhaust strategies on the drying characteristics of fire hoses, a performance test of fire hose heat pump device was designed. The test results show that after the implementation of the exhaust strategy, the heating coefficient of the system is increased by 2.8%, and the dehumidification capacity per unit energy consumption is increased by 13.5%. After the implementation of the bypass strategy, the heating coefficient of the system increased by 8.5% and the dehumidification capacity per unit of energy consumption increased by 24.5%. The final results of the study show that compared with the traditional open-close integrated drying mode, the combined operation mode of bypass and exhaust is more effective in terms of energy saving.

Key words: heat pump drying system, fire hoses, drying system performance, bypass and exhaust, combined operating modes