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Ground source heat pump (GSHP) systems are well established as an energy‐efficient space conditioning device. However, for better utilization of the ground source, improvement in GSHP performance is desirable, which limits the small temperature difference between the ground and the circulating fluid. In this study, efforts have been made to investigate the performance of a ground heat exchanger (GHX) with a nanofluid as a heat carrier. Mathematical modeling is performed for the closed‐loop vertical U‐tube GHX with six different (Al2O3, CuO, graphite, multiwalled carbon nanotube, graphene, and Cu) water‐based nanofluids. The effect of different operating parameters on GHX length, fluid temperature, and pressure drop with nanofluids is determined. On the basis of the analytical results, it is found that the graphite particle‐based nanofluid plays a prominent role to enhance the performance of the GHX as compared with other nanoparticles. The maximum enhancement in the increase in outlet fluid temperature and reduction in pipe length with graphite particle‐based nanofluid are 68.3% and 63.3%, respectively, for an increase in temperature difference from 7°C to 15°C between the atmosphere and the ground. Also, with the graphite particle‐based nanofluid and the increase in pipe diameter from 20 to 50 mm, the fluid outlet temperature increases up to 11.2%, and the requirement in GHX length reduces up to 55%.

The materials used for the slurry transportation system experience erosion wear due to the impact of suspended solid particles. In the present experimental investigation, a large size slurry pot tester was used to investigate the slurry erosion behavior of steel 304L, grey cast iron, and high chromium white cast iron in the velocity range of 9.0–18.5 m/s. Experiments were conducted by rotating the wear specimens in the pot tester at 1% weight concentration of Indian standard sand. The erosion behavior of the three target materials was evaluated by varying the orientation angle from 15 to 90 deg and particle size from 256 to 655 µm. The erosion rate was found to increase with velocity having power index value varying between 2 and 3, which increases with an increase in impact angle and depends on the target material. The erosion rate of the material also increases with the increase in particle size with the power index varying between 0.8 and 1.4 depending on the target material. No significant change was noticed in the mechanism of erosion of the target materials with the variation in velocity in the present range of test conditions. Empirical correlations are proposed to estimate the total erosion rate of all the three materials as a contribution of cutting and deformation wear.

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