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Investigation of coolants

Industry

on request

Dr. Steffen Feja

+49-351-4081-5411

Secondary loop refrigerants

Freezing point

Standard:

ASTM D 1177

Instrument:

Freezing tube with stirrer; cooling bath

Principle:

A test tube containing the coolant is cooled down in a clear-view thermostat under constant stirring, until a crystal formation in the absence of supercooling occurs. The temperatur at which the crystallisation begins is called the freezing point.

Temperature range: 

–70 °C to RT

Amount of sample required:

100 ml

Amount of sample required:

100 ml

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Solidification point/Pour point

Standard:

based on DIN EN ISO 3016

Instrument:

Freezing tube with stirrer; cooling bath

Principle:

The coolant is cooled down slowly until at a certain temperature it shows no flow behavior.

Temperature range: 

–60 °C to 100 °C

Amount of sample required:

100 ml

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Specific heat capacity

Standard:

ASTM D 3947 bzw. E 1269

Instrument:

Differential scanning calorimeter Setaram µDSC VII or  Differential scanning calorimeter TA Instruments Q200

Principle:

Thermal effects of the sample can be detected in dependence of temperature and time by continuous heating, cooling or isothermal operation mode and comparing with a reference. For instance these effects can be freezing, melting, phase changing effects, chemical reaction and so on.

Temperature range:

–45 °C to 90 °C up to 20 bar
-180 °C to 750 °C pressureless

Pressure range:

1 to 20 bar

Sensitivity 0,2 µW

Range of measurement:

1.7 – 2.5 kJ kg–1 · K–1

Amount of sample required:

10 ml

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Thermal conductivity

Instrument:

test cell for stationary cylinder gap method

Principle:

The coolant to be measured is placed in a gap between a heatable inner and an outer cylinder. The inner cylinder is heated with a defined rate. After the heat flow is stationary the temperature difference of the liquid in the gap is measured with Pt100 temperature sensor.

Temperature range:

-40 °C to 140 °C

Pressure range:

1 to 100 bar

Range of measurement:

50 - 200 mW · m–1 · K–1

Amount of sample required:

250 ml

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Vapor pressure

Instrument:

test cell for determination of vapor pressure (625 cm3)

Principle:

The test cell is tempered and the vapor pressure is determined with direct method.

Temperature range:

-60 to 140 °C

Pressure range:

 10-3 to 130 bar

Amount of sample required:

500 ml

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Vapor pressure of liquid lubricants (of aqueous solutions) by isoteniscope method

Standard:

ASTM D 2879

Instrument: Isoteniscope (self made)

Principle:

 

The test fluid is put into a U-shaped pipe. After preheating to volatilize non condensable gases the fluid is cooled stepwise. A vapour consisting of gaseous fluid molecules (oil or sole) is formed in the u pipe. The fluid is the sealing liquid by itself. With the help of nitrogen the meniscuses will be held at the same height in the u pipe. The vapour pressure of the nitrogen corresponds to the pressure of the liquid and is measured with sensors applied behind the isoteniscope.

This method accords to methods described in REACH for measuring the vapour pressure of liquids.

Temperature range:

-40 °C to 140 °C

Pressure range:

1 to 1000 mbar

Amount of sample required:

250 ml

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Density

Standard:

DIN 51757

Instrument:

Oscillating U-tube density meter DPR 412 Y /DMA 60 (Anton Paar)

Principle:

A defined volume of the sample is filled into a U-shaped glass tube which is electronically excited into undamped oscillation. The eigenfrequency of this U-tube is depending on the mass of the sample. The density is calculated from the frequency of oscillation.

Temperature range:

-10 °C to 140 °C

Pressure range:

1 to 160 bar

Range of measurement:

600 to 1300 kg · m–3

viscosity:

< 15.000 mm2 · s-1

Amount of sample required:

250 ml

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Dynamic viscosity

Standard:  ASTM D 7483

Instrument: 

Oscillating piston viscometer (Cambridge Viscosity)

Principle:

Oscillating piston viscometers allow dynamic viscosity measurement of a broad range of materials including transparent, translucent and opaque liquids. The measurement itself is automatic and does not require an operator to time the oscillation of the piston. The electromagnetically driven piston mixes the sample while under test. Kinematic viscosity can be calculated by dynamic viscosity and density.

Temperature range:

-40 to 140 °C

Pressure range:

1 to 140 bar

Range of measurement:

0,2 -20.000 mPa · s

Amount of sample required:

250 ml

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Reserve alkalinity

Instrument:

Methrom Tritrino

Standard:

ASTM D 1121

Principle:

The reserve alkalinity is the amount of 0,100 N HCl in ml, which is necessary to reach pH 5.5 of 10 ml sample.

Amount of sample required:

10 ml

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Corrosion test

Standard:

ASTM D 1384

Principle:

Metal specimens are totally immersed in the tempered and aerated coolant. Prior to and after testing the specimens are weighted.

Temperatur:

88 ± 2 °C

Amount of sample required:

3 l (triple test)

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DSC Measurments

Standard:

several

Instruments:

Differential scanning calorimeter Setaram µDSC VII or Differential scanning calorimeter TA Instruments Q200

Principle:

 

Besides the measurement of heat capacity of solids and fluids following material parameter are measurable with differential scanning calorimetry at the ILK:

  • Melting and crystallization enthalpies and temperatures
  • Storage capacity of PCM according RAL-standard
  • Glass transition of synthetic material
  • Decomposition enthalpy and temperature
  • Reaction enthalpy (pressure dependent on request)
  • On request: absorption  enthalpy of gases in gas storage material (i.e. zeolite)

Temperatur range:

-40 °C to 750 °C

Pressure range: 1 bar (whole temperature range); 1 to 100 bar (-45 to 90 °C)

Amount of sample required:

1 ml or 1 mg

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Further test can be carried out if questioned.


Your Request

Further Projects

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Practical training, diploma, master, bachelor

Student training - Education at ILK

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Test procedures for electrical components

Insulating properties of hermetic compressors

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3D - Air flow sensor

Anemometer for determination of 3d-air flow