Performance comparison and suitability evaluation of shell and tube heat exchangers for greenhouse environments using CFD and TRNSYS

Heat exchangers are essential for maintaining target temperatures in greenhouse environments, and shell-and-tube heat exchangers (STHEs) provide a high heat-transfer area and structural robustness. However, previous studies have mainly focused either on CFD-based analyses of STHE thermal performance or on greenhouse energy simulations with simplified heat-source representations; therefore, studies that directly incorporate a CFD-derived STHE thermal–hydraulic performance map into a dynamic whole-greenhouse simulation for suitability evaluation under realistic outdoor conditions remain scarce. In this study, CFD was used to quantify STHE heat transfer and pressure drop across operating conditions, and the resulting performance maps were coupled with TRNSYS greenhouse simulations under dynamic outdoor conditions to assess operational suitability. The analyses show that heat transfer and pumping power increase with STHE mass flow rate, indicating a clear trade-off between thermal benefit and hydraulic penalty. Under the investigated conditions, the STHE delivered up to 815.12 W of heat-transfer capacity with a corresponding pumping power of 113.15 W, and the higher mass-flow case (0.25 kg/s) showed improved capability to satisfy greenhouse temperature/load requirements. The proposed CFD–TRNSYS framework can support practical sizing and operation guidelines for selecting suitable STHE operating conditions for greenhouse heating and cooling.