Refrigeration

PX G1300 for Refrigeration

Energy Recovery’s PX G1300 (PX G) energy recovery device is designed to enhance the safety, operability, reliability and environmental sustainability of commercial and industrial carbon dioxide (CO2) refrigeration systems.

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With the PX G, CO2 refrigeration systems can potentially lower operating expenses by increasing the energy efficiency of the system.

Our PX G prototype is currently undergoing rigorous testing and early results indicate that the PX G can potentially increase standard CO2 system efficiency by up to 50% in higher ambient temperatures*. Moreover, our testing suggests that the PX G can outperform the leading energy recovery technology for CO2 refrigeration systems on the market today – ejector technology – in both moderate and high ambient temperatures. 

Compared to ejector technology, the PX G’s relative performance improves as temperatures rise. This improvement occurs because as temperatures rise, the pressure differentials needed to create the refrigeration cycle also increase. While ejector technology typically manages less than 200 PSI / 14 bar of pressure differential boost, providing a limited efficiency improvement, the PX G is able to manage full differential boost as required by the system, and therefore continues to perform as temperatures rise.  

Global Regulation is Driving Adoption of CO2 Systems

Hydrofluorocarbon (HFC) refrigerants are greenhouse gases that have been used in commercial and industrial refrigeration systems for years. Unfortunately, HFCs pose a significant threat to our climate, contributing thousands times more to global warming than CO2. The Kigali Amendment, an amendment to the Montreal Protocol, targets an 80% reduction in HFC use by 2047 and is driving the global cold chain to transition to refrigerants with lower environmental impact. The European Union, the U.S. Environmental Protect Agency, and some U.S. states have followed suit with similar initiatives, some of which propose more aggressive transition time tables than the Kigali Amendment. The U.S. EPA, the United States’ environmental protection regulatory body, for example, proposed rules in May 2021 to decrease the production and import of HFCs in the United States by 85% over the next 15 years starting in 2022. 

This regulation is expected to drive a surge of CO2 system installations, however, CO2 is not without its hurdles. CO2 systems are costlier to operate than HFC systems, requiring higher pressures and, therefore, more energy to achieve the same refrigeration results. CO2 system efficiency also steadily degrades as the ambient temperature rises, therefore limiting adoption of CO2 refrigeration in warmer climates. The PX G offers a potential solution to this higher temperature hurdle, aiming to reduce the operating cost disadvantage of CO2 systems in higher ambient temperatures. 

With the significant energy savings enabled by Energy Recovery’s PX G, CO2 refrigeration has real potential to break through the barrier of the CO2 equator, a geographical limit for the cost-effectiveness of CO2 refrigeration systems, and replace the high global warming potential – known as high GWP – refrigerants used by 95% of supermarkets in that zone.

How the PX G1300 Works in a CO2 Refrigeration System

The PX G uses Energy Recovery’s trusted pressure exchanger technology, a versatile technology that recycles pressure energy within industrial fluid-flow systems and can handle gas and liquids. Many of Energy Recovery’s products, including our award-winning PX® Pressure Exchanger® for seawater desalination, use pressure exchanger technology.  Just like our PX Pressure Exchanger recycles the pressure energy of seawater in desalination to save energy, our PX G for CO2 refrigeration can recycle the pressure energy in a CO2 system. This reduces the energy consumption in the system, as well as related costs and emissions.

The PX G has two main functions in a CO2 refrigeration system: 

1. Expansion Valve and 
2. Compressor Booster. 

The PX G can act like an expansion valve and a compressor at the same time, increasing CO2 system performance and reducing main compressor loads.

The PX G operates alongside the high-pressure valve of the refrigeration system. Instead of simply throttling the pressure energy at a high-pressure valve, the PX G harvests the energy to reduce compressor work and reduce power requirements. Diminished compressor work saves energy and reduces compressor duty cycles, leading to lower maintenance needs for the system while increasing safety and ease of use. 

*Temperatures above 90° F/32° C