Prepared and supplied by BITZER.
Propane (R290) is a colourless and odourless gas that belongs to the family of hydrocarbons.
Propane is a highly efficient refrigerant that has gained popularity in recent years due to its excellent thermodynamic properties and low environmental impact. This article will discuss the applications, specialties, handling, and future outlook of R290 in refrigeration systems.
Propane has a low global warming potential (GWP) of 3 and zero ozone depletion potential (ODP), making it a viable alternative to conventional refrigerants with high GWP values. It has been used in various refrigeration and air conditioning applications, including commercial, residential, and industrial settings. R290 is commonly used in small-scale refrigeration systems, such as refrigerators, freezers, and air conditioning units. Additionally, it is also used in larger commercial and industrial refrigeration applications, such as food storage and processing, chemical processing, and cold storage.
Overview over flammable refrigerants
According to the ISO 817 standard, today’s refrigerants can be classified into categories A and B. While category A includes non-toxic substances, category B includes toxic refrigerants. Flammability is classified in four groups (1 = non-flammable, 2L = flammable with slow flame spread, 2 = flammable,
3 = highly flammable).
The most important substances of safety group A3 that can be used as refrigerants are hydrocarbons such as propane (R290), propene (R1270), isobutane (R600a), butane (R600) or ethane (R170), which have a long history in refrigeration and air conditioning technology and were a model for the development of many synthetic refrigerants. Group A3 refrigerants are highly flammable. They can be ignited at proportions as low as about two and as high as ten percent in the air. In the medium mixing range, ignition can be achieved by the spark of a light switch, a steel tool falling on a stone floor or a statically charged sweater, causing violent deflagrations or explosions. The combustion residues are in particular carbon dioxide and water and thus in themselves usually harmless when everything has cooled down again.
Specialties of R290 in refrigeration systems
The use of flammable substances has a long history in household appliance technology and commercial refrigeration. Towards the end of the 19th century, the use of the non-toxic but highly flammable hydrocarbons became widespread due to their good thermodynamic properties, along with ammonia, sulphur dioxide and carbon dioxide. Propane (R290) is well suited to commercial refrigeration and also for air conditioning and heat pumps. It boils at -42 °C and can cover evaporating temperatures of -40 °C and higher. Large temperature strokes are easily possible when compressing with this substance.
R290 has a high cooling capacity, which means it can remove a large amount of heat in a short amount of time. It also has a high coefficient of performance (COP), which measures the efficiency of the refrigeration cycle.
How to secure safety in refrigeration systems with R290
R290 is a highly flammable gas that could pose a safety risk if not handled properly. Therefore, propane-based refrigeration systems must be designed and installed with safety features that minimize the risk of fire and explosion. These safety features include pressure relief valves, flame arrestors, and leak detection systems. Handling R290 as a refrigerant requires special precautions to ensure safety. Only qualified and trained personnel shall handle R290 as a refrigerant, for example they should wear appropriate personal protective equipment (PPE) such as goggles, a portable gas detector and electrostatic dissipative gloves. When installing propane-based refrigeration systems, it is essential to follow local and national codes and standards. These codes and standards provide guidelines for the safe installation, operation, and maintenance of propane-based refrigeration systems. Regular maintenance and inspections are crucial to ensure the safe and efficient operation of refrigeration systems ran with R290.
When assembling the refrigeration system without refrigerant charge, the known rules are applied in principle, even in the case of flammable A2L or A3 refrigerants. The most important thing is to be aware of the potential flammability and explosion risk when handling the refrigerant. Safety becomes even more critical during maintenance and servicing work, when the refrigerant is already in the system, and it may have to be opened. Here, the highest safety precautions must be taken to minimize the risk of accidents. The formation of an explosive atmosphere should be avoided in any case. Especially in the case of A3 refrigerants, even stricter requirements must be observed. Due to the extreme oil solubility of hydrocarbons, there is still a risk of dangerous quantities of refrigerant outgassing from the oil even after the extraction process has been completed.
Among other things, the following aspects should be observed during maintenance and servicing work (list not exhaustive):
- Ensuring that the room is well ventilated, for example with a fan brought in with the unit
- Ensure that there are no sources of ignition within reach
- Personal protective equipment, for example a portable gas detector and electrostatic dissipative gloves
- Use of approved ‘non-sparking’ tools
- Use of gas sensors and shut-off devices
- Appropriate fire extinguishing equipment
Efficient components for systems with flammable refrigerants
BITZER supports its customers in dealing with flammable refrigerants with guidelines and a practical training program at the SCHAUFLER Academy. In addition, the portfolio of the refrigeration, air conditioning and heat pump specialist includes a wide range of products that are approved for the use of flammable refrigerants, including R290. These include, for example, oil separators, liquid receivers, condensers, evaporators, reciprocating compressors of various sizes as well as compact screw compressors for air conditioning or process cooling.
Optionally available for ECOLINE reciprocating compressors is the mechanical capacity control. Alternatively, the equipment with VARIPACK frequency converters ensures precise adaptation to the respective refrigeration demand. Via a separately mounted IQ module, it is possible to integrate the products into the BITZER Digital Network (BDN), which is based on BITZER’s compressor know-how and creates a service infrastructure for even more efficient operation and high component availability.
Future outlook for R290 in refrigeration systems
R290 is a viable alternative to conventional refrigerants with high GWP values, offering high cooling capacity, high efficiency, and low environmental impact. As the world continues to move towards more sustainable and environmentally friendly solutions, the demand for propane as a refrigerant is expected to increase. The use of R290 in refrigeration systems is expected to grow in the coming years, particularly in commercial and industrial applications.
The future outlook for propane in refrigeration systems depends on various factors, including regulatory requirements, technological advancements, and market trends. With ongoing research and development in the field of refrigeration technology, new and improved propane-based refrigeration systems are expected to emerge in the market, providing more efficient and cost-effective cooling solutions. With the increasing demand for sustainable and environmentally friendly refrigeration solutions, the use of R290 is expected to grow in the coming years.
BITZER Refrigerant Report Online Edition
All relevant information on refrigerants at a glance: Since 1992, the BITZER Refrigerant Report has provided the industry with a reliable reference work. The new, significantly expanded version is available exclusively online and is thus always up to date in terms of regulations and specifications, as well as including an overall table with filter function on refrigerants.