The direct contact heat exchanger has great application potential in compressed air energy storage (CAES) systems. However

there is limited research on the gas-liquid two-phase direct contact heat and mass transfer characteristics under pressurized conditions

as well as the lack of theoretical references for heat exchanger design. In this study

based on computational fluid dynamics (CFD) methods

a model for the gas-liquid flow

heat transfer

and mass transfer during the countercurrent direct contact between hot

humid air and cooling water in a spray-type direct contact heat exchanger is established. The study investigates the dynamics of droplet motion within the heat exchanger under operating pressures of 0.1

0.4

and 0.7 MPa

the effects of gas velocity and gas-water ratio on convective condensation heat transfer

and analyzes the pressure loss of the heat exchanger. The results indicate that the critical air velocity for droplet escape decreases with increasing operating pressure. For droplets with a particle diameter of 1 500 μm and an axial velocity of 10 m/s

the critical air velocities at operating pressures of 0.1

0.4

and 0.7 MPa are approximately 6.5

3

and 2.5 m/s

respectively. For each operating pressure

there is an optimal air velocity and gas-water ratio that result in the best heat and mass transfer performance of the heat exchanger. The spray-type direct contact heat exchanger has the advantage of low-pressure loss

making it highly suitable for applications involving gas-liquid two-phase heat and mass exchange under high operating pressures. The findings can be used to guide the structural design and process optimization of direct contact heat exchangers and provide theoretical support for the development of heat exchangers.