Experimental and numerical investigation of an internally pinned externally finned compact cooler for high power density shearer ranging arms
Year: 2026
Type: preprint
Abstract: With the sharp increase in power density of shearer ranging arms used in thin coal seam mining, frequent failures due to overheating in the ranging arm gearbox have become a critical issue. As the core component for heat dissipation in the ranging arm, the heat transfer performance of the cooler is crucial for suppressing high temperature failures. Owing to the complex underground working environment and limited installation space, the key challenge lies in effectively enhancing cooling performance without altering the existing cooler dimensions and installation configuration. To address this, this paper proposes a high efficiency internally pinned and externally finned cooler. This cooler utilizes a pin structure within a small diameter tube and optimizes the external fin structure and layout, successfully resolving the conflict between efficient heat dissipation and structural size constraints within a limited space. Furthermore, the heat transfer enhancement mechanism of the pin structure is revealed, and its disturbing effect on the flow is analyzed. The pin structure disrupts the thermal boundary layer and viscous sublayer of the flow, significantly improving the cooler's heat transfer performance. To validate the effectiveness of the new cooler, a comparative experimental platform was designed and constructed, and comparative experiments were conducted between the internally pinned externally finned cooler and the original cooler. The experimental results show that the heat transfer performance of the new cooler is significantly superior to that of the original cooler. Under stead state conditions with a cooling water flow rate of 0.28 kg/s, the average equivalent heat transfer coefficient of the new cooler reaches 2031.03 W/(m²·K), representing a 30.83% improvement over the original cooler. Under dynamic conditions, its average equivalent heat transfer coefficient is 1889.13 W/(m²·K), a 45.00% improvement, with an average heat transfer rate of 9.62 kW, which is 1.44 times that of the original cooler. CFD numerical simulation results agree with experimental data within an error of 6.91%, further verifying the intrinsic enhancement mechanism of the internally pinned externally finned cooler through boundary layer disturbance. This study provides a composite enhanced heat dissipation 1 solution for the thermal optimization of high power density shearer ranging arms in thin coal seams, with significant engineering application value and promotional prospects.
Source: Research Square
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7225818365
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