HYDROCARBON FACTSHEET

GENERAL PROPERTIES OF HYDROCARBON REFRIGERANTS

· Hydrocarbon Refrigerants are Safe and Non-toxic.

· Hydrocarbon Refrigerants are Non-Corrosive.

· Hydrocarbon Refrigerants are Environmentally Friendly.  They are Non-Ozone  Depleting and has negligible Global Warming Potential.

· Hydrocarbon Refrigerants are made from Natural Organic material.

· Hydrocarbon Refrigerants are fully compatible with R12, R134a and R-22 lubricants.

· Hydrocarbon Refrigerants are highly efficient, reducing fuel consumption when used in auto A/C, quicker temperature drop in vehicle compartment and drastic reduction in operating head pressure which results in longer A/C components life

 

· Hydrocarbon Refrigerants are flammable.

· Hydrocarbon Refrigerants are safe to use with proper handling.

· Hydrocarbon Refrigerants have an AUTO IGNITION point of 1585 F, which is higher than R134a at    1328 F.

· Hydrocarbon Refrigerant molecules are larger (lower density) than R12 and R134a, therefore, smaller charge per application.

· Hydrocarbon Refrigerants does not become caustic if contaminated with moisture or oxygen.

 

Hydrocarbon Refrigerant atmospheric life is less than one year, compare with  R12, 130years and R134a 16 years.

· Hydrocarbon  Refrigerants have been in use since 1867, and in conjunction with ammonia, were the most widely used refrigerants before the introduction of CFCs in the 1930s.

· Hydrocarbon Refrigerants are now available in Trinidad and Tobago.

· They have low viscosity and high thermal conductivity that allow good performance of the system

· They possess high chemical stability

 

Hydrocarbon Refrigerant Types

 

Pure Isobutane—R-600a

It is a single component HC        refrigerant with a normal boiling point of 11.8 °C. This refrigerant, in spite of having sub-atmospheric pressure at suction, has been widely considered as one of the practical solutions for new domestic refrigerator technology.

Its volumetric refrigeration capacity is lower than CFC-12.  The R-600a   compressor requires a greatly    increased swept volume to give the same capacity

It has very good energy efficiency.  Also, the R-600a systems are    quieter than other systems

 

HC Blends (R-290/R-600a)

Propane-Isobutane Mixture

These refrigerants can be used with             compressors designed for CFC-12 and   R-22 with only minor changes needed to electrically components to maintain safety. 

The mixture possesses very high latent heat of vaporization and low density.  The charge   volumes are approximately 40% that of  CFC-12.

They operate with a lower compression ratio, thus improving the operation of the             compressor.

The propane-isobutane mixture is a zeotropic blend.  The temperature glide is around 8°C.

 

FLAMMABILITY

Hydrocarbons are flammable and      ignition sources have to be avoided and/or eliminated.

Lower Flammability Limit (LFL) and Upper Flammability Limit (UFL) of   Hydrocarbon Refrigerants:

The LFL for R-600a is 1.85% & HC Blend is 1.95% - approximately 35g/m³  of air

The UFL for R-600a is 8.5% and HC Blend is 9.1% - approximately 165g/m³  of air.

For example, if there is less than 1.95% of HC blend in air, then there is        insufficient fuel from the refrigerant for combustion.  If there is more than 9.1%, there is insufficient oxygen form the air for combustion.

It is virtually impossible for combustion to occur inside a completely and correctly charged refrigeration cycle as there will be insufficient air

 

General Safety Consideration

 

 

The Following Actions are Strongly  Recommended or Mandatory:

· Prohibit  smoking within the     charging area

· Earth all fixed metal objects in the area

· Use flame proof motors for all new installations

· Introduce intrinsically safe devices with barrier protection

· Continuous monitoring of the     environment for explosive/flammable vapours

· Used only sealed or non-sparking electrical components

· Leak test as part of routine  maintenance

· Replace electrical components with solid state

· Re-locate electrical components away from the refrigeration circuit

· Install leak detection alarms/systems

· Pressure test, leak test and evacuate the system before brazing or   unbrazing joints

· Charge appliances in a well ventilated area which must be at least 2 metres away from ignition sources

· Label the equipment clearly to show that the refrigerant is hydrocarbon, the amount and that it is flammable

· Have  a fire extinguisher (dry powder type) available at all times

 

Transportation and Storage of Hydrocarbon Refrigerant

 

 

 

Hydrocarbon refrigerant should be transported and stored in the same way as other flammable gases. It is best to store these gases as follows;

· In a secure locked compound    protected from weather and direct sunlight

· The cylinder valves should be closed and capped

· The storeroom should be well   ventilated (ventilator fan) and sealed off

· A flammable gas alarm must be fitted next to the cylinder or in the storage area.

· Never heat cylinders or leave   exposed in the sun

· Transport cylinders in open       vehicles, in an upright stable     position

· Do not smoke where hydrocarbons are stored

· Have in place dry powder type fire extinguishers

· Do not use switches within 2     meters of charging area.

· Wear gloves, goggles and clothing which cover the body

 

This information and adapted from  (1) working safely with hydrocarbons and (2) the Cuban experience (3) National Ozone Unit—Grenada