INCORPORATING COLD CHAIN
FEATURE
EBM‐PAPST ' S COMPACT HIGH- SPEED TURBO COMPRESSORS
Earlier this year ebm-papst announced it was expanding its product portfolio to include turbo compressors for different air and gas mixtures . These turbo compressors are used in heat pumps , self-contained drinking water systems and gas supply systems for fuel cells , for example . All components , from the drive motor to the compressor impeller and the newly developed oil-free high-speed bearings , are coordinated to suit the specific application .
Designed as a platform solution , individual compressors with outputs from 1 to 45 kW can be quickly assembled and different refrigerants , air and other gas mixtures can be compressed without oil . Thanks to their high speeds , the turbo compressors are more compact than conventional solutions , operate vibration-free and do not require any lubricating oil . This is of interest wherever gas purity is required . The gas bearing , which is not subject to contact or friction during operation , not only achieves a long service life but also has impressively low noise levels .
The new compressor platform enables a wide range of different applications to be operated economically . By combining different impeller sizes and blade geometries , it enables optimum aerodynamic adaptation to the application . This means that , depending on requirements , the impellers can be matched to the required mass flow or pressure ratio and the working gases used , such as air or R290 .
The P1 ( 1 kW ) and P2 ( 2.8 kW ) platforms are already available as prototypes and are also in use in customer applications . Series production processes were already considered in the concept phase , which will contribute to a competitive cost structure in future series production . With the help of the technical centre currently under construction at the main site in Mulfingen , Germany , the first small series will start as early as the beginning of 2024 . Series production , which is planned from 2026 , is aiming for volumes significantly higher than one hundred thousand units per year and platform size .
DANFOSS ’ TURBOCOR
According to Danfoss ’ website its Turbocor compressor is an oil-free magnetic bearing compressor designed for the HVAC industry . It is known for its high efficiency , low sound levels , and compact footprint . The compressor utilises advanced technology such as oil-free , magnetic bearings that provide world-class efficiency and zero performance degradation over the life of the compressor . Some of its key features and benefits :
• Energy efficiency : it is 35 % more energy efficient , achieved through its built-in Variable Frequency Drive ( VFD ) that optimises speed based on varying load conditions . Being oil-free , it eliminates the need for an oil management system , preventing performance degradation over time . The friction-free magnetic bearings reduce wear and tear , resulting in improved long service life .
• The Turbocor compressor can be used in air-cooled , water-cooled , or evaporative-cooled chillers across a wide range of applications such as comfort cooling , low-temperature
Sabroe Sabroe
Packaged chiller with low charge Ammonia and small footprint , like the Sabroe ChillPAC supplied by Johnson Controls , hold potential .
processes , ice storage , and heat recovery . It is equipped with intelligent features such as voltage fluctuation sensing and self-monitoring capabilities .
DC COMPRESSOR MANAGEMENT ( DRIVEN BY CAREL )
Compressors with permanent magnet motors controlled by DC inverters are one of the most efficient technologies available in the world for HVAC / R applications , says CAREL .
This technology , originating from Japan , is becoming the market standard in home air-conditioning and heating applications . For almost 10 years , CAREL has been helping to disseminate this technology in both refrigeration and air-conditioning applications , especially the most energyhungry of these , such as heat pumps , air-conditioners for data centers , water chillers , condensing units and refrigerated showcases .
The results are energy savings of up to 60 % thanks to the capacity to adapt to the cooling or heating demand in real time ; down to less than 10 % of the nominal load , with minimum power consumption and consequent extremely high seasonal energy efficiency ratio when compared to the most diffuse fixed speed compressor units .
All of this would not be possible without the Power Plus family of inverters , the only devices available on the market that can control 100 + different models of DC compressors , among scroll , rotary , twin rotary and reciprocating technologies , made by the world ’ s leading manufacturers , with
A Recip Compressor . cooling capacities up to 50kW or 90cc displacement .
These also include various refrigerant applications , such as HCFs ( for example , R410A , R404A , R407C , R134a ), natural refrigerants ( such as CO 2
, propane ) and options , such as liquid injection , vapour injection , vertical or horizontal layout .
Being combined with the pCO and c . pCO series controllers , and Electronic Expansion Valves of the ExV family , this ‘ CAREL system ’ integrates the compressor ’ s electrical and thermodynamic characteristics , and is engineered based on in-depth lab tests conducted in collaboration with the compressor manufacturers .
Maximum efficiency and total reliability are therefore guaranteed by dynamic control of the compressor envelope , the area in which correct operation is guaranteed . However , when dealing with thermodynamics , the compressor envelope control is just the tip of the iceberg .
Dedicated functions have been developed to manage any compressor operating variable , such as discharge and sump temperatures , oil circulation , suction and discharge superheat as well as speed ramps and start-up and stop procedures . CAREL ’ s experience in this sector has also allowed this system to be upgraded with exclusive functions to protect the compressor and optimise the entire refrigeration system .
These are the reasons why the Power Plus is actually a compressor drive , rather than just a ‘ general purpose ’ inverter , as the
Bock
The Bock HG56e offers a high level of efficiency and quiet during operation . motor speed control is just a small portion of all its numerous functions dedicated to the compressor management .
In the end , this CAREL control system is integrated into the final HVAC & R application , for example a heat pump , a condensing unit or a showcase so as to ensure the technology meets all the needs of the OEM and of the end user . Some examples ?
• When driving water chillers , the Carel DC compressor system is able to directly control the water outlet temperature , reducing or even zeroing the need of a water tank buffer and allowing a more strict humidity control on the hydronic terminals .
• When driving a refrigerated plugin display case , its precise capacity modulation allows one to reduce the number of defrosts per day with a consequent reduction of the energy cost of this application and makes the food temperature a ‘ straight line ’ without any oscillating behaviour increasing the products life .
• When driving a computer room air conditioning system , its capability to modulate compressor , expansion valve and fans allows the unit to run out of the design working conditions for hours ( for example , at unexpected external ambient temperatures ) without compromising any component and without interrupting the essential cooling duty . CLA
Compressors with permanent magnet motors controlled by DC inverters are one of the most efficient technologies available
REFERENCES :
1 . https :// www . copeland . com / en-us / products / heating-and-air-conditioning / residentialscroll-compressors / modulating-compressors
2 . https :// www . copeland . com / en-us / products / heating-and-air-conditioning / residentialscroll-compressors / modulating-compressors
3 . https :// www . carel . com / dc-compressormanagement 4 . Danfoss website 5 . Emb-papst website 6 . https :// www . thomasnet . com / articles / machinery-tools-supplies / understandingcompressors /
COLD LINK AFRICA • November 2023 www . coldlinkafrica . co . za 19