The reliable determination of the properties of refrigerant-oil mixtures enables the safe design and optimization of refrigeration systems. Well-founded data on miscibility, temperature behavior, and heat transfer increase operational reliability and support the selection of suitable combinations for demanding operating conditions.

Based on our extensive experience, we are pleased to offer support in selecting application-specific refrigerant-oil systems. Below you will find a selection of established test methods for the qualification of new working fluids.

The following determination methods are used to investigate the properties of refrigerant-oil mixtures as a function of temperature, pressure and composition. Based on the measured data obtained, reliable conclusions can be drawn regarding miscibility, temperature behavior over a wide range and the suitability of refrigerant-oil systems under real operating conditions.

Floc Point

• According to DIN 51351
• Pressure-resistant glass autoclave, transparent thermostat
• Temperature range: -60 °C to room temperature
• Pressure range: 0 to 70 bar
• Modifications: Nebula test (5 wt.% oil), floc point determination of immiscible liquids (= refrigerants saturated with oil, e.g. mineral oil with R717)

Pourpoint

• According to DIN EN ISO 3016 (pour point); DIN 51583 (solidification point)
• Temperature range: -65 °C to room temperature
• Pressure range: 0 to 160 bar
• Modifications: The determination of the pour point of refrigerant-oil mixtures is carried out by viscosity measurement up to 20,000 cP, followed by extrapolation of the measured temperature to a limiting viscosity.

Miscibility Gap

• According to DIN 51514
• Pressure-resistant glass autoclave, transparent thermostat
• Temperature range: -60 to 120 °C
• Pressure range: 0 to 80 bar
• Modifications: The miscibility gap can also be determined via vapor-liquid equilibrium between refrigerant and oil. This is required for systems with very low miscibility, such as ammonia-mineral oil or synthetic hydrocarbon oils.

Vapor Pressure

• Vapor pressure measurement cell with magnetic coupling
• Temperature range: -80 to 140 °C
• Pressure range: 0 to 130 bar
• Higher temperatures and pressures available on request

Density

• According to DIN 51757
• Oscillating U-tube density meter DMA HPM (Anton Paar)
• Temperature range: -10 (-40) to 140 °C
• Pressure range: 0 to 160 bar
• Higher temperatures and pressures available on request
• Measurement range: 600 – 1,300 kg · m^-3 (15,000 mm² · s^-1)

Dynamic / Kinematic Viscosity

• According to ASTM D 7483
• Vibrating piston viscometer (Cambridge Viscosity)
• Temperature range: -40 to 140 °C
• Pressure range: 0 to 160 bar
• Measurement range: 0.2 to 20,000 mPa · s
• Higher temperatures and pressures available on request

Specific Heat Capacity

• According to ASTM D 3947 and ASTM E 1269
• DSC µDSC7 evo (Setaram) and DSC Q 200 (TA Instruments)
• Temperature range: -40 to 120 °C and -90 to 300 °C, respectively
• Pressure range: 0 to 100 bar

Thermal Conductivity

• Measurement cell for the steady-state concentric cylinder method
• Temperature range: -40 to 140 °C
• Pressure range: 0 to 30 bar