Tootfinder

A Study on Optimizing the Thermal Performance of Coaxial Heat Exchanger Systems in Medium-Deep Geothermal Wells
Haonan Chen, Xin Tong, Linchao Yang, Yangxue Zhang
https://arxiv.org/abs/2509.14141

A Study on Optimizing the Thermal Performance of Coaxial Heat Exchanger Systems in Medium-Deep Geothermal Wells
Medium-deep geothermal energy is a key renewable source, but existing coaxial downhole heat exchanger (DHE) systems suffer from low efficiency and temperature decay. This study evaluates the impacts of circulating flow rate, inlet temperature, and operation mode on DHE performance, using field data from two geothermal wells (Well A: 3200m, 130.5$^{\circ}$C; Well B: 2500m, 103.3$^{\circ}$C). Results show that under an optimal condition (LC3: 50 m$^3$/h, 30$^{\circ}$C), Well A's heat extraction r…

Vortex controlled heat transfer in eight row plate fin and tube exchangers: CFD derived air side Nusselt correlations
Mateusz Marcinkowski, Kacper Korab
https://arxiv.org/abs/2509.08611

Vortex controlled heat transfer in eight row plate fin and tube exchangers: CFD derived air side Nusselt correlations
This paper investigates and characterizes the row dependent thermal performance of an 8 row finned tube heat exchanger (HEX) with an offset tube arrangement and continuous flat fins. Computational fluid dynamics (CFD) simulations reveal distinct hydraulic thermal behavior across the tube rows, with the first, second, and eighth rows exhibiting significantly higher heat transfer efficiency than the average for the entire HEX under specific flow conditions. At air velocities below 3 ms-1, the fir…

Fabrication of the HFVMTF Double-Bath Cryostat
R Bruce (Fermi National Accelerator Laboratory), V Nikolic (Fermi National Accelerator Laboratory), T Tope (Fermi National Accelerator Laboratory), O Oshinowo (Fermi National Accelerator Laboratory), G Velev (Fermi National Accelerator Laboratory), T Vo (Ability Engineering Technology Inc), M Maurisak (Ability Engineering Technology Inc)
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Fabrication of the HFVMTF Double-Bath Cryostat
The High Field Vertical Magnet Test Facility (HFVMTF) at Fermilab is designed to test superconducting magnets up to 20 tons and 1.3 meters in diameter. Central to the facility is a double-bath superfluid helium cryostat reaching 1.8 K at 1.2 bar. Integrated with a 15 T superconducting dipole from LBNL, HFVMTF supports HTS cable testing for fusion applications. This paper presents the design and fabrication of the cryostat, with a focus on two complex components: the 2 K heat exchanger and the l…

Sparse Narrow-Band Topology Optimization for Large-Scale Thermal-Fluid Applications
Vladislav Pimanov, Alexandre T. R. Guibert, John-Paul Sabino, Michael Stoia, H. Alicia Kim
https://arxiv.org/abs/2508.04261

Sparse Narrow-Band Topology Optimization for Large-Scale Thermal-Fluid Applications
We propose a fluid-based topology-optimization methodology for convective heat-transfer problems that can manage an extensive number of design variables, enabling the fine geometric features required for the next generation of heat-exchanger designs. Building on the classical Borrvall--Petersson formulation for Stokes flow, we develop a narrow-band optimization algorithm that concentrates computational effort on the fluid--solid interface, where it is most needed. To address the high cost of re…

A lightweight numerical model for predictive control of borehole thermal energy storages
Johannes van Randenborgh, Steffen Daniel, Moritz Schulze Darup
https://arxiv.org/abs/2507.20974

A lightweight numerical model for predictive control of borehole thermal energy storages
Borehole thermal energy storage (BTES) can reduce the operation of fossil fuel-based heating, ventilation, and air conditioning systems for buildings. With BTES, thermal energy is stored via a borehole heat exchanger in the ground. Model predictive control (MPC) may maximize the use of BTES by achieving a dynamic interaction between the building and BTES. However, modeling BTES for MPC is challenging, and a trade-off between model accuracy and an easy-to-solve optimal control problem (OCP) must…