Investigations of heat transfer and hydrodynamics in heat exchangers with compact arrangements of tubes

•A new design of heat exchanger with compact arrangement of small diameter tube bundles.•Numerical model for new design of heat exchanger.•Numerical model is validated by experimental testing.•Influences of dynamic and geometric parameters on the efficiency of heat exchanger is analyzed.•Heat transfer and hydrodynamics process in channels of small diameter tube bundles is discussed. The paper presents the main results of theoretical and experimental investigation of hydrodynamics and heat transfer processes in heat exchangers with a compact arrangement of small diameter tubes. A new design of heat exchangers is proposed, in which there are no gaps and shifting in the direction of transverse to the flow between adjacent tubes. Numerical modeling of heat transfer processes and hydrodynamics for turbulent flow of heat-carrier and experimental investigations of hydrodynamic and heat transfer characteristics of new designs of heat exchangers with compact bundles of small diameter tubes are carried out. The analysis results demonstrated that the proposed designs of shell-and-tube heat exchangers have dimensions of 1.7–2 times smaller and mass is 10–15% lower compared to heat exchangers of traditional designs with the same heat power. The findings in this work may provide a theoretical basis for the selection of optimal designs of shell-and-tube heat exchangers with tube bundles.