Measurement of electrical properties of refrigerants and refrigerant–oil mixtures

Feja, Steffen

doi:10.1016/j.ijrefrig.2012.03.011

Cited by 16 publications

(8 citation statements)

References 8 publications

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“…Values concerning the DC resistivity of R134a and R152a were first published by Fellows et al 8 and later by Feja 9 . Fellows tested the resistivities using both AC and DC voltages and measured the DC resistivity for R134a and R152a to be 6.6 × 10 8 Ωm and 2.2 × 10 7 Ωm, respectively.…”

Section: Introductionmentioning

confidence: 95%

“…Fellows tested the resistivities using both AC and DC voltages and measured the DC resistivity for R134a and R152a to be 6.6 × 10 8 Ωm and 2.2 × 10 7 Ωm, respectively. Feja 9 tested several electrical properties, including the relative permittivity, dielectric dissipation factor, and DC resistivity, across a temperature range between − 30 and 90 °C, and tested mixtures with different concentrations of polyester oil. They found the DC resistivity of R134a and R152a to be 10 8 Ωm and 10 7 Ωm, respectively.…”

Section: Introductionmentioning

confidence: 99%

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Liquid resistivity of pharmaceutical propellants using novel resistivity cell

Ahmad,

Rasekh,

Manivannan

et al. 2023

Sci Rep

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Metered-dose inhalers employ propellants to produce pharmaceutical aerosols for treating respiratory conditions like asthma. In the liquid phase, the DC volume resistivity of pharmaceutical propellants, including R134a, R152a, and R227ea, was studied at saturation pressures and room temperature (not vapour phase). These measurements are essential for industries like refrigerants. Aerosols from metered dose inhalers (MDIs) with these propellants become electrically charged, affecting medicament deposition in lung. The resistivity was measured using a novel concentric cylinder-type capacitance cell designed in-house. The resistivity for the propellants (R134a, R152a, and R227ea) was found to be 3.02 × 1010 Ωm, 2.37 × 109 Ωm and 1.31 × 1010 Ωm, respectively. The electrical resistivity data obtained was found to be at least two orders of magnitude higher than the limited data available in the literature. Challenges in the resistivity cell’s development and performance are discussed, with a focus on various propellants and their mixtures with ethanol and moisture concentrations. The resistivity of propellant mixtures containing moisture concentrations ranging from 5 to 500 ppm and ethanol concentrations ranging between 1000 and 125,000 ppm was determined. The resistivity was tested across 10-min and 1-h periods and was performed in accordance with the contemporary IEC 60247 standard.

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Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Liquid resistivity of pharmaceutical propellants using novel resistivity cell

Ahmad,

Rasekh,

Manivannan

et al. 2023

Sci Rep

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“…Due to the lack of experimental data, the electromagnetic properties of R134a were assumed to be constant for all five frequen- cies. Electric conductivity of R134a was assumed to be 4.17×10 −9 S m −1 [17,18], while its relative permittivity and relative permeability were set as constants and equal to 9.1 and 1.0, respectively [19]. Electric and magnetic field magnitude distributions for 100 MHz are shown in Fig.…”

Section: Case 2: Stagnant R134a Refrigerant Effect On Electromagneticmentioning

confidence: 99%

Effect of cooling fluids on high frequency electric and magnetic fields in microelectronic systems with integrated TSVs

Abdoli

Reddy

Dulikravich

et al. 2017

Microelectronics Journal

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A B S T R A C TA fully 3D conjugate numerical analysis was performed to reveal the effects of air, R134a refrigerant and water on electromagnetic fields of electronic cooling designs made of arrays of micro pin-fins with integrated Through-Silicon-Vias (TSVs). The integrated TSV cooling configuration included 8 cylindrical TSVs with 150 µm diameter each and 200 µm height. The external dimensions of the silicon substrate were 900×700×280 µm. Each TSV encapsulated four equally spaced copper vias each having a diameter of 40 µm. The impacts of the presence of the stationary cooling fluids without heat transfer on TSVs electric and magnetic fields were examined for five different frequencies; 100 MHz, 500 MHz, 1 GHz, 5 GHz and 10 GHz. Then, separately, the effects of moving cooling water with temperature-dependent physical properties were studied while exposing the cooled micro pin-fin array to a uniform heat flux of 500 W cm −2 . For the case of stagnant and moving cooling fluids it was found that water influences the electric field twice as much as either R134a or air and that this influence decreases only negligibly with the increase in frequency of the electric current passing through the TSVs. The influence of the presence of the stagnant and moving cooling fluids on the magnetic field is orders of magnitude smaller and reduces rapidly with the increased frequency.

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“…24 The second SCF selected is 1,1-difluoroethane (CHF 2 CH 3 ), which has a critical temperature and critical pressure (p c ) of 386.4 K and 4.52 MPa, 22 respectively. It has a high dipole moment (2.27 D) 21 and dielectric constant (e r = 7 at 363.15 K and 2.9 MPa) 25 among the HFCs, making it a potential supercritical fluid for dissolving ionic species and carrying out electrodeposition. 26 In order to compare the phase and conductivity behaviours with those in CH 2 F 2 , the two well-characterised supporting electrolytes ([N( n C 4 H 9 ) 4 ][BF 4 ] and [N( n C 4 H 9 ) 4 ][B{3,5-C 6 H 3 (CF 3 ) 2 } 4 ]) were chosen and the measurements were made at 393.15 K, i.e.…”

Section: Introductionmentioning

confidence: 99%

“…24 The second SCF selected is 1,1-difluoroethane (CHF 2 CH 3 ), which has a critical temperature and critical pressure (p c ) of 386.4 K and 4.52 MPa, 22 respectively. It has a high dipole moment (2.27 D) 21 and dielectric constant (e r = 7 at 363.15 K and 2.9 MPa) 25 among the HFCs, making it a potential supercritical fluid for dissolving ionic species and carrying out electrodeposition. 26 The phase equilibrium of the binary systems with the HFC (CH 2 F 2 or CHF 2 CH 3 ) was studied by using a variable-volume view cell, the detailed description of which can be found in the literature.…”

Section: Introductionmentioning

confidence: 99%

Phase behaviour and conductivity of supporting electrolytes in supercritical difluoromethane and 1,1-difluoroethane

Han

Suleiman

et al. 2016

Phys. Chem. Chem. Phys.

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We present investigations into a variety of supporting electrolytes and supercritical fluids probing the phase and conductivity behaviour of these systems and show that they not only provide sufficient electrical conductivity for an electrodeposition bath, but match the requirements imposed by the different precursors and process parameters, e.g. increased temperature, for potential deposition experiments. The two supercritical fluids that have been explored in this study are difluoromethane (CH2F2) and 1,1-difluoroethane (CHF2CH3). For CH2F2, the phase behaviour and electrical conductivity of eight ionic compounds have been studied. Each compound consists of a cation and an anion from the selected candidates i.e. tetramethylammonium ([N(CH3)4](+)), tetrabutylammonium ([N((n)C4H9)4](+)), 1-ethyl-3-methylimidazolium ([EMIM](+)) and 1-butyl-3-methylimidazolium ([BMIM](+)) for cations, and tetrakis(perfluoro-tert-butoxy)aluminate ([Al(OC(CF3)3)4](-)), chloride (Cl(-)), trifluoromethyl sulfonimide ([NTf2](-)) and tris(pentafluoroethyl)trifluorophosphate ([FAP](-)) for anions. For CHF2CH3, [N((n)C4H9)4][BF4] and [N((n)C4H9)4][B{3,5-C6H3(CF3)2}4] have been investigated for comparison with the previously measured solubility and conductivity in CH2F2. We have found that [N((n)C4H9)4][Al(OC(CF3)3)4], [N((n)C4H9)4][FAP] and [N(CH3)4][FAP] have much higher molar conductivity in scCH2F2 at similar conditions than [N((n)C4H9)4][BF4], a widely used commercial electrolyte. Additionally, scCHF2CH3 shows potential for use as the solvent for supercritical fluid electrodeposition, especially at high temperatures since high density of this fluid can be achieved at lower operating pressures than similar fluids that can be used to produce electrochemical baths with comparable conductivity.

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Measurement of electrical properties of refrigerants and refrigerant–oil mixtures

Cited by 16 publications

References 8 publications

Liquid resistivity of pharmaceutical propellants using novel resistivity cell

Liquid resistivity of pharmaceutical propellants using novel resistivity cell

Effect of cooling fluids on high frequency electric and magnetic fields in microelectronic systems with integrated TSVs

Phase behaviour and conductivity of supporting electrolytes in supercritical difluoromethane and 1,1-difluoroethane

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