All the thermohydraulic systems experience entropy generation due to which the performance is found to be degrading. Similarly, due to the flow of coolant such as LN2 (77 K) in the High Temperature Superconducting (HTS) cables, cause the entropy generation. This is due to the friction in the corrugated former through which the coolant flows and due to the finite heat transfer between the coolant and other solid components of the HTS cables. Existence of entropy generation in such thermohydraulic system results in higher pumping power and decrease in heat transfer cause disruption to the state of superconductivity. Hence, in the present work, a detailed investigation on the losses due to entropy generation is done and its effect on the degradation in the performance of HTS cables is presented. As there are no experimental methods to measure the entropy generation, computational method using a commercial code is adapted in estimating the degradation in terms of destruction in exergy. The computational domain is modeled, meshed and analyzed using commercial software ANSYS®. The analysis is carried out with time averaged Reynolds averaged Navier-Stokes (RANS) equations which are solved using Finite Volume Method (FVM) of discretization with κ−ε turbulent scheme. As the thermophysical properties of LN2 are sensitive to the operating temperature (77 K and pressure of 2.7 bar), temperature dependent properties are considered. Further, the flow rates ranging from 11 to 20 L/min and the heat loads ranging from 1 to 3 W/m are considered to estimate the entropy generation rate and exergy destruction. The results obtained from the computational investigation are validated with the experimental results that are available in the literature. From the analysis, it is observed that higher the heat loads higher will be the entropy generation and hence higher exergy destruction. The minimum exergy destruction is possible at the minimum entropy generation rate for different flow rates and heat loads.