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Title: 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.more » This technique will drastically increase the forward current ratings and reliability of the PE device« less

Authors:
 [1];  [1];  [1];  [1];  [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Power Electronics and Electric Machinery Research Facility
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
931713
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: IEEE Transactions on Industry Applications; Journal Volume: 43; Journal Issue: 3
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; EXTRAPOLATION; HEAT FLUX; HEAT SINKS; INVERTERS; RECTIFIERS; REFRIGERANTS; RELIABILITY; SIMULATION; COOLING

Citation Formats

Lowe, Kirk T, Tolbert, Leon M, Ayers, Curtis William, Ozpineci, Burak, and Campbell, Jeremy B. Two-Phase Cooling Method Using R134a Refrigerant to Cool Power Electronic Devices. United States: N. p., 2007. Web.
Lowe, Kirk T, Tolbert, Leon M, Ayers, Curtis William, Ozpineci, Burak, & Campbell, Jeremy B. Two-Phase Cooling Method Using R134a Refrigerant to Cool Power Electronic Devices. United States.
Lowe, Kirk T, Tolbert, Leon M, Ayers, Curtis William, Ozpineci, Burak, and Campbell, Jeremy B. Mon . "Two-Phase Cooling Method Using R134a Refrigerant to Cool Power Electronic Devices". United States. doi:.
@article{osti_931713,
title = {Two-Phase Cooling Method Using R134a Refrigerant to Cool Power Electronic Devices},
author = {Lowe, Kirk T and Tolbert, Leon M and Ayers, Curtis William and Ozpineci, Burak and Campbell, Jeremy B},
abstractNote = {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},
doi = {},
journal = {IEEE Transactions on Industry Applications},
number = 3,
volume = 43,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Experimentally obtained values are presented for the dynamic viscosity of the R134a gaseous refrigerant in a little-studied range of parameters. A comparison is made with available experimental data on supercritical isotherms and with known analytic dependences.
  • A quantitative method of image processing coupled with the neutron radiography technique is proposed to accurately measure the void fraction of a two-phase flow in a metallic duct. The spatial distribution of the dark current component is experimentally shown to be smooth, and the temporal variation cannot be ignored. Since the neutrons scattered in an object can be smoothed and reduced by setting the test section at a large distance from the converter, it is clarified that the corrections for the dark current and scattered neutrons can be represented by an offset. The offset value can be determined by usingmore » the total macroscopic cross section of the object ({Sigma}-scaling method). By comparing the calculated void fractions with the measured ones obtained by simulating the known void profile using a standard test section, the void fraction can be measured by this method within 2% error. The measurement error is estimated to be up to {approximately}10% when no correction for scattered neutrons is made or arbitrary offset values are used.« less
  • Refrigerants R134a (1,1,1,2-tetrafluoroethane) is a leading substitute for refrigerant R12. As such, there has been worldwide activity to develop accurate wide-range equations of state for this fluid. In this study, we have developed a new selection algorithm for determining high-accuracy equations of state in the Helmholtz representation. This method combines least-squares regression analysis with simulated annealing optimization. Simulated annealing, unlike stepwise regression, allows for the controlled acceptance of random increases in the objective function. Thus, this procedure produces a computationally efficient selection algorithm which is not susceptible to the function-space local-minima problems present in a purely stepwise regression approach. Twomore » equations are presented in this work and compared against experimental data and other high-accuracy equations of state for R134a. One equation was produced strictly by using stepwise a regression algorithm, while the other was produced using the simulated-annealing selection algorithm. In both cases the temperature dependence of the equations was restricted to have no terms whose exponents were greater than five.« less
  • An equation of state and tables of thermodynamic properties of R134a in the saturation state and in the one-phase region are obtained in the temperature interval 320-500 K at pressures ranging from 0.01 to 7.5 MPa.
  • Thermoelectric coolers or Peltier coolers are used to pump heat in the opposite direction of the natural heat flux. These coolers have also been proposed for electronic cooling, wherein the aim is to pump heat in the natural heat flux direction and from hot spots to the colder ambient temperature. In this manuscript, we show that for such applications, one needs to use thermoelectric materials with large thermal conductivity and large power factor, instead of the traditionally used high ZT thermoelectric materials. We further show that with the known thermoelectric materials, the active cooling cannot compete with passive cooling, andmore » one needs to explore a new set of materials to provide a cooling solution better than a regular copper heat sink. We propose a set of materials and directions for exploring possible materials candidates suitable for electronic cooling. Finally, to achieve maximum cooling, we propose to use thermoelectric elements as fins attached to copper blocks.« less