The refrigeration and air conditioning industry (RAC) increasingly relies on equipment manufacturers to 'lead the way' when it comes to selecting “proven products” that use natural refrigerants.
Customers want to know that these products are proven in their field and can deliver energy efficiencies and cost savings.
An example of this is in the area of industrial refrigeration where low charge systems are gaining recognition for enabling a significant reduction in the amount of ammonia charge required while still delivering operational efficiency for the plant.
This in turn leads to future cost savings and complies with national safety regulations for large plants with > 1500 kgs of ammonia. At Mayekawa this successful approach to replacing HCFC facilities with natural refrigerants is known as the Newton concept.
It has been particularly successful in Japan where it has been introduced at a broad range of HCFC cold storage facilities.
This success is why the Newton concept has been openly supported by the Japanese Government. The Newton system uses ammonia as a primary refrigerant, and this ammonia charge is maintained in the package, which is located in the plant room. There is no risk of ammonia in the working space.
Plus, it involves a very small charge of ammonia making the concept particularly attractive to end users. CO2 is pumped around to evaporators in the cold rooms, plus both low and medium temperature applications are available.
The use of new rotor profiles in the semi-hermetic screw compressor, coupled with an IPM motor (Interior Permanent Magnet) enables a small five to 10 per cent higher efficiency over conventional induction type motors.
This semi-hermetic screw compressor is driven by a variable speed drive, assuring superior part load performance and the double economizer allows an increase in supercooling, delivering improved efficiency and capacity.
Shell and Plate heat exchangers (condenser and evaporator) are incorporated, as these permit a small approach temperature for the evaporator while allowing for the refrigerant charge is kept to a minimum.
The entire product package incorporates all of these new technologies including ammonia (NH3) refrigerant cycles, the CO2 liquefaction, receiver and CO2 pump.
The units are run tested at the factory before delivery which means that all the contractor needs to do on-site is connect piping and electrical parts for cooling water, CO2 and the power supply.
This shortens the installation time significantly. Remote monitoring can also be achieved with the assistance from the Mayekawa factory in Japan. Visit www.mayekawa.com.au