DESIGN AND PERFORMANCE VALIDATION OF A DUAL-FUNCTIONAL ABSORPTION HEAT EXCHANGER

The large-scale utilization of low-grade waste heat is a key trend for district heating systems under the carbon neutrality strategy, necessitating large-temperature-difference technology for long-distance heat transport.This technology creates a "temperature ratio mismatch" problem due to the severe mismatch in fluid flow rates between the primary and secondary sides of the heating network.To address this, the Absorption Heat Exchanger (AHE) was developed.It has evolved into two main functional types: the first-type AHE, based on an Absorption Heat Pump (AHP) cycle for lowering the primary network's return water temperature, and the second-type AHE, based on an Absorption Heat Transformer (AHT) cycle for upgrading the temperature of low-grade heat sources.However, in applications requiring both functions, the conventional approach of deploying two separate units increases system complexity and investment.This paper reports on the design, fabrication, and experimental validation of a novel Dual-Functional Absorption Heat Exchanger (DFAHE).The device utilizes interchangeable falling-film components within a reconfigurable system architecture, allowing a single unit to switch between AHP and AHT operational modes.Experimental results demonstrate that the unit operates stably in both modes and achieves the intended thermodynamic functions.The findings indicate that a single, reconfigurable unit can perform the roles of two distinct devices, offering a compact and flexible alternative for waste heat recovery and temperature grade management in district heating systems.