An emphasis on decreasing refrigerant charge is bringing about innovations in industrial refrigeration technologies, particularly in CO2/NH3 and ammonia DX systems.
CIMCO Refrigeration partners with Mayekawa to bring CO2/NH3 NewTon to U.S.
In order to offer a new industrial solution to the North America market that avoids many of the pitfalls of large-scale NH3 plants, including high ammonia charges, CIMCO Refrigeration has partnered with Mayekawa to bring the prefabricated NH3/CO2 NewTon package to the U.S. With a minimised ammonia charge and automatic control, the NewTon simplifies onsite construction because only minimal packaging and wiring is required. The NH3/CO2 solution has a new screw compressor, semi-hermetic IPM motor, flooded evaporator, and double economizer.
To date around 500 NewTons have been successfully installed in Japan. In the U.S., CIMCO recently completed its second NewTon installation, in California, where the system will be run alongside an R507 system to allow EPRI to compare the performance of both systems.
Benoit Rodier, CIMCO’s Director of Business Development who presented the NewTon at ATMOsphere America 2015 said that despite resistance to using new technology, and the higher price of the NH3/CO2 package, if one considers maintenance and service, the total cost of ownership is not much higher - “we have to help the owner to consider the total cost of ownership. CIMCO has another ten NewTon projects in the pipeline.
NH3/ CO2 cascade refrigeration system for a grocery store remodel proves energy savings
In another presentation focused on NH3/CO2 cascade solutions, Rob Arthur, Principal/Director of Refrigeration Engineering at CTA, discussed an installation at an existing 117,000ft2 (10,870m2) commissary in San Antonio, Texas. The water-cooled refrigeration plant has 81lbs (35.7kg) of ammonia and 1,800 lbs (816kg) of CO2.
NH3/CO2 was chosen as the only suitable, all natural refrigerant equipment available at that time and although the ROI (Return on Investment) was not favourable - calculated at 20 years, the demonstration project used 8% less energy compared to the original system. What is more, the first cost differential between the NH3/CO2 system and an R404A system was less than projected.
Arthur believes there is a large potential market for NH3/CO2 cascade systems in the U.S. but that the public must be made aware of the safety of low charge systems and that costs need to come down.
Resurgence in interest in advanced ammonia DX systems
In their joint presentation, Terry Chapp, National Business Development Manager at Danfoss and Jeremy Olberding, Vice President of Sales at Colmac Coil Manufacturing explained the advantages of ammonia DX using the example of an installation at the 403,000 ft2 (37440 m2) Joliet cold storage facility in Illinois. The installation, which uses economized screw compressors with thermosyphon oil cooling, has a DX ammonia charge of 7,300 lbs (3,311kg), much lower than the estimated ammonia charge for a pumped system (25,175 lbs or 11,419kg). It also has lower power consumption than with HFCs and a two-three year payback.
Although a few technical challenges had to be addressed in the initial stages of the project, such as stratified/ wavy flow in the evaporator tubes and refrigerant distribution in the evaporators, the system is a value added alternative to HFC systems. Thanks to advanced electronic controls using state of the art algorithms, ammonia DX systems have become a safe and proven technology that can eliminate the regulatory and liability burden that accompanies large charge systems.
Standard packaged ammonia equipment and custom solutions from Stellar
In a lunchtime Technomercial, Stellar’s Marc Turner, National Director of Sales, reviewed the benefits of packaged refrigeration equipment, such as cost savings, space savings, and improved safety thanks to the isolation of ammonia to the machine room. Stellar offers standard packages mounted on a structural steel base complete with interconnecting piping, valves, and instruments, alongside custom solutions. Their systems offer a very low ammonia charge of 1lb / TR.