The impact of ambient heat ingression on performance of cryogenic three-fluid cross-flow compact heat exchanger

Abstract

The upshot of the improper insulation of the thermal system is the substantial instability and degradation in the thermal effectivity. The heat interaction between the ambient and heat exchanger shroud is initiated due to insufficient insulation, poor insulating material and/or the deterioration of the insulation over time. The dynamic investigation of the compact three-fluid heat exchanger (3-FHE) with cross-flow configuration (C1,2,3and4) under ambient heat ingression (both non-uniform and uniform) is conducted. The ‘Implicit Finite Difference’ scheme is implemented to perceive the numerical solution which is followed by experimentation to check the authenticity of the solution. Additionally, the ‘Dankwert's boundary condition’ which signifies the dispersive heat conduction in the fluids at the inlet section of the core and along the flow length; all along with the conduction of heat longitudinally in the exterior and parting walls is involved which has come up as the most practical model. It is learnt that the expeditious attainment of steady-state is observed under ambient heat ingression. It is engrossing to mention that the axial dispersion (AD) and longitudinal heat conduction (LHC) escorts in lower deterioration in cooling effectivity by 20.22% and 9.14% respectively under ambient heat ingression. The C1 configuration offers maximum drop of 41.8% in thermal effectivity under the varying magnitude of uniform heat ingression factor from 1 to 10. The adjacent fluids which are adhered to the non-insulating exterior wall reflect considerably early ‘temperature cross’ with the central hot fluid.