Lead Performer: Oak Ridge National Laboratory – Oak Ridge, TN
July 11, 2023
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Lead Performer: Oak Ridge National Laboratory – Oak Ridge, TN
Partners:
-- Emerson Climate Technologies
-- Hussmann
-- Chemours
DOE Total Funding: $450,000
Cost Share: $450,000
Project Term: January 1, 2023 – January 1, 2024
Funding Type: CRADA
Project Objective
Current supermarket refrigeration systems are a significant source of CO2 emissions from both direct (refrigerant leaks) and indirect (energy consumption) sources. The direct emissions are due to leaks of high global warming potential (GWP) refrigerants such as R-404A (GWP of 3922) while the indirect emissions are due to centralized refrigeration systems that are not fully optimized for energy efficiency. Environmental regulations require significant reductions of greenhouse gas emissions by 2029 and beyond, which will require lower GWP refrigerants and highly efficient systems. Hence, there is a clear need to enable the use of improved technologies for both equipment and refrigerant. A distributed scroll booster system is proposed as an alternative for current refrigeration systems. The distributed scroll booster is configured to enable the use of low-pressure refrigerants such as R-1234yf (GWP less than 1) in a cycle configuration that employs a two-stage compression process. This scroll booster system is comprised of medium-temperature compressors (high stage) coupled with low-temperature compressors (low stage). Both low-temperature and medium-temperature refrigerated display cases are integrated in the same system. By design, this system reduces the refrigerant charge, produces higher efficiencies (two-stage compression), uses existing components minimizing cost impact, and will be able to use ultra-low GWP class A2L (low toxicity and low flammability) refrigerants such as R-1234yf when standards and building codes are updated (expected by 2025).
This project will include laboratory and field evaluations of the distributed scroll booster equipment. Laboratory evaluations will be performed with the flammable refrigerant R-1234yf, and all required safety precautions will be taken. Field evaluations will be performed using the same refrigerant and applying all required safety mitigation to ensure the safety of the end-users. The laboratory evaluation will be performed at Oak Ridge National Laboratory using a fully instrumented system, allowing the detailed measurement of performance (capacity, efficiency) under a wide range of operating conditions. This level of scientific rigor will establish a clear proof of concept and generate at least one journal publication. The field evaluation will be performed in at least two end-user facilities and is intended to measure energy consumption and main system parameters for a period of 12 to 18 months, allowing the evaluation of the system exposed to all-year seasons with the associated thermal loads and ambient conditions. Additionally, the project will undertake commercialization activities to further advance the technology to become a commercially viable product for Emerson Climate Technologies Inc.
Project Impact
This project will achieve a substantial reduction of approximately 60% in greenhouse gas emissions within the supermarket segment, and energy savings of up to 5% compared to current central DX R404A systems. Additionally, the adoption of smaller-footprint systems deployed in a distributed manner, along with reduced refrigerant requirements, offers benefits such as lowered installation and maintenance costs. This approach not only facilitates quicker deployment but also enhances the potential to reach disadvantaged communities more effectively.
Contacts
DOE Technology Manager: Payam Delgoshaei
Lead Performer: Vishal Sharma