High performance cooling of a HVDC converter using a fatty acid ester‐based phase change dispersion in a heat sink with double‐layer oblique‐crossed ribs

Abstract

The paper concerns with a high performance cooling method for a HVDC converter using fatty acid ester-based phase change dispersion (PCD) in a heat sink with double-layer oblique-crossed ribs. Thermo-physical properties of PCDs were first characterized under both solid and liquid states, and the cooling performance of the heat exchanger was then experimentally examined, by heating two copper blocks clamped closely to the aluminium heating surfaces. A threedimensional Euler-Euler multiphase approach was further performed to evaluate the thermal performance under different operating conditions including heating power, flowrate and PCD concentration. The results showed that the

Heat Transfer Performance Potential with a High-Temperature Phase Change Dispersion

“…Within high power transmission systems and devices such as HVDC converters, issues arise with thermal management, as within these systems, there is a high power dissipation, which can be up to 30% of the total HVDC power loss [13]. Not only does this cause problems with thermal runaway in the system, but the power losses resulting from the high power dissipation result in large maintenance costs for the operating plants [14,15]. Currently, to prevent this, there are two common methods that are employed-water cooling and air cooling.…”

“…Currently, to prevent this, there are two common methods that are employed-water cooling and air cooling. Air cooling, which is used through either forced or natural flux through cooling air channels, is normally used for electronic devices with power dissipation rates below 1500 W [14,16]. However, in the case of HVDC, this value can be up to 10 kW, and for this, air is not sufficient [13,14,17].…”

“…Air cooling, which is used through either forced or natural flux through cooling air channels, is normally used for electronic devices with power dissipation rates below 1500 W [14,16]. However, in the case of HVDC, this value can be up to 10 kW, and for this, air is not sufficient [13,14,17]. Water has a high cooling efficiency; however, only sensible heat can be exploited [16], as the cooling of HVDC converters is required at 50 degrees.…”

Phase Change Dispersion Made by Condensation–Emulsification

“…Its apparent viscosity is a complex function of shear rate, the content of the dispersed phase, and temperature (liquid or solid PCM). In ref ( 1 ), detailed information on this behavior is described. For the purpose of assessment of the increase in the content of the dispersed phase, a single curve at a constant shear rate shall be the basis, as depicted in Figure 8 b.…”

“…Additionally, batteries or electric components are sensitive to conductive coolants. 1 Manufacturers of battery systems are therefore investigating alternatives like low viscosity oils and/or other dielectric liquids. However, any such solution will have specific heat capacities (usually around 2 kJ/kg·K) far below that of water (around 4.2 kJ/kg·K), resulting in higher flow rates, lesser efficiencies, and greater energy losses.…”