One of the challenges with industrial transcritical CO2 equipment is the limitation of compressor horsepower available in the marketplace. In some larger projects this can lead to the need for additional systems causing the equipment to become not as competitive, or physically not as viable, when compared to a central ammonia or an HFC system. On these larger capacity projects this is due in part to not having transcritical CO2 compressors above 50 HP available in the marketplace.
Italian compressor manufacturer Dorin is looking to change this. Dorin, who was founded in 1918 and has been in the compressor manufacturing business since 1932, developed their CO2 compressor in 1995 and began manufacturing CO2 compressors for sale in 1999. Seeing the need for larger semi-hermetic CO2 compressors, especially in the industrial market, Dorin has now developed new larger CO2 compressors with a range of up to 100 HP. This compressor is not exactly new any longer. Dorin has been successfully selling this compressor since 2017 in Europe. However, in 2020 they received UL approval for the compressor in the United States. These are currently the largest semi-hermetic transcritical CO2 compressors available in the world.
Design Technologies
Dorin has incorporated some of their unique CO2 compressor designs into their new larger CO2 compressors. Some of the technologies they have adopted from the automotive industry.
For example, Dorin has incorporated an external discharge manifold. This manifold is very similar to what you see on your car’s internal combustion engine. According to Dorin this design has many advantages over other CO2 compressor designs where the discharge plenum is inside the compressor housing. Some of the advantages Dorin claims are:
- Lower oil temperature – especially during the warmer months during trans-critical operation
- Higher efficiencies
- Lower discharge temperatures – providing better oil separation, smaller gas cooler requirements, and smaller thermal stress on heat recovery plate heat exchangers
- Longer compressor life
Dorin has also engineered a specific gas stream that is designed to keep oil in the compressor sump. This helps with oil recovery and, with less oil in the system, increases overall system efficiency.
This compressor has been widely adopted in Europe for larger scale industrial CO2 projects. Giacomo Pisano tells me that Dorin is now working on a 150 HP CO2 compressor that they hope will be ready to release at the end of this year. These larger horsepower compressors will certainly make CO2 more competitive in the larger industrial applications here in the United States. Stay tuned for these exciting new CO2 compressor developments here in the United States!