Thermal and hydraulic performance of caseless, pinless and gasket-free spiral plate heat exchanger

Heat exchangers are fundamental components across numerous industries, contributing significantly to efficiency and thermal performance by facilitating the transfer of heat between fluids. Optimizing their effectiveness and thermal performance remains a key objective. This study introduces a novel design for spiral plate heat exchangers (SPHEs), addressing limitations in conventional designs through significant structural modifications. A new SPHE design tailored for specific heat exchange duties was developed, overcoming several challenges of traditional configurations. This design was translated into a physical model and subjected to extensive evaluation. A computational fluid dynamics (CFD) model was also developed to provide deeper insights into the thermal dynamics of the SPHE system, with the model validated using experimental data collected from a purpose-built test rig integrated with the new SPHE. Experimental studies were conducted to evaluate the thermal and hydraulic performance of the new SPHE compared to conventional designs. Key parameters examined included the Reynolds number (Re), ranging from 1000 to 2400, and the hot liquid inlet temperature, varying from 80 °C to 50 °C. Thermal performance metrics showed notable improvements with the new SPHE design, achieving average increases of 28 % in heat exchange rate, 6.75 % in effectiveness, 17.3 % in the number of transfer units (NTU), and 35.3 % in the Biot number (Bi). Hydraulically, the new design demonstrated superior performance, with average reductions of 32.1 % in pressure drops and corresponding improvements of 32.1 % in the Euler number and 61 % in the Jensen number. These results highlight substantial advancements in the thermal and hydraulic efficiency of the proposed SPHE, coupled with improvements in structural design and manufacturing processes. Future research is recommended to evaluate the new design in specific applications, such as district cooling systems and energy conversion and storage systems, to further validate its advantages under practical operating conditions.