Two-phase cooling method using R134a refrigerant to cool power electronic devices

Abstract

 This paper presents a two-phase cooling method using R134a refrigerant to dissipate the heat energy (loss) generated by power electronics (PE) such as those associated with rectifiers, converters, and inverters for a specific application in hybrid-electric vehicles (HEVs). The cooling method involves submerging PE devices in an R134a bath, which limits the junction temperature of PE devices while conserving weight and volume of the heat sink without sacrificing equipment reliability.First, experimental tests that included an extended soak for more than 300 days were performed on a submerged IGBT and gate-controller card to study dielectric characteristics, deterioration effects, and heat flux capability of R134a. Results from these tests illustrate that R134a has high dielectric characteristics, no deterioration on electrical components, and a heat flux of 114 W/cm 2 for the experimental configuration. Second, experimental tests that included simultaneous operation with a mock automotive air-conditioner (A/C) system were performed on the same IGBT and gate controller card. Data extrapolation from these tests determined that a typical automotive A/C system has more than sufficient cooling capacity to cool a typical 30 kW traction inverter.Last, a discussion and simulation of active cooling of the IGBT junction layer with R134a refrigerant is given. This technique will drastically increase the forward current ratings and reliability of the PE device.

Permittivity-based void fraction sensing for microfluidics

“…During microcooler testing at the Division of Applied Mechanics and Energy Conversion of the KU Leuven this flow regime was confirmed using R134a, a common refrigerant. Since the di↵erence in permittivity between liquid and gaseous R134a is only 0.5 [20], as well as for safety reasons, water and air were preferred for the testing (and simulating) of the sensors. Testing of the sensors is further discussed in section 4.…”

Spray Cooling With HFC-134a and HFO-1234yf for Thermal Management of Automotive Power Electronics

“…Another study by Campbell et al [32] and Ayers et al [33] showed that thermal management of power electronics is vital to the operation of hybrid electronic vehicles. They also suggested that R134a has no damaging effect on the normal operation of the submerged IGBT.…”

Floating Refrigerant Loop Based on R-134a Refrigerant Cooling of High-Heat Flux Electronics

“…Life tests with capacitors, an insulated gate bipolar transistor (IGBT), and a gate-driver printed circuit board showed no adverse affects when in direct contact with the refrigerant. The life tests have been conducted over a period of 15 months with periodic functional tests of the circuitry and visual inspections of the components and wiring occurring almost monthly [4].…”