|
|
||
|
From Hitachi America, Ltd. / Industrial Systems Division
When applying an inverter to centrifugal compressors on HVAC chillers, there are a number of factors to consider. For some compressors, lubricating oil circulation may be driven by the rotation of the compressor shaft itself, via a gear-driven pump arrangement. If you slow the motor speed, the volume of oil provided for bearings, etc. will be reduced. The lube oil pump may have to be replaced or modified. Consult the compressor manufacturer to determine any special requirements. Not all centrifugal compressors can be adapted cost-effectively to variable speed operation. Some chillers have built-in logic which may be tied into the existing starter. A modification may be required from the chiller manufacturer to allow proper operation with a VFD. You may need to bypass the control logic of the existing chiller and use temperature or pressure feedback and PID to optimize speed control while not compromising the safeties of the built-in logic system. Speed control should take precedence over compressor vane control. Products & Services
Refrigeration compressors and air conditioning compressors provide air conditioning, heat pumping, and refrigeration for large-scale facilities and equipment. Refrigeration compressors are sometimes called refrigerant compressors.
Pressure blowers and fans are used to create and sustain a positive pressure for inflatable structures, clean rooms, laboratories, and medical facilities. Pressurization blowers are fans that create a positive pressure in a sealed or restricted environment.
Industrial fans and blowers are designed to move air and/or powders in industrial and commercial settings. Typical applications include air circulation for personnel, exhaust or material handling.
Industrial cooling systems and equipment includes air-to-air, liquid-to-air, and liquid-to-liquid heat exchangers; ducts and/or pipes; and other devices for removing heat from a system that contains a heat source.
Product Announcements
Topics of Interest
HEAT GENERATORS (HEATING PLANTS)
Considerable improvements in the seasonal efficiency of conventional heating plant equipment, such as boilers and furnaces, were made over the last several decades.
(Read More)
4-20 mA vibration monitoring of chillers and cooling units
Cooling towers, process coolers and HVAC cooling units can be monitored for vibration using the 4-20 mA analog input channels of existing PLC...
(Read More)
Chapter List
Chapter 6: Centrifugal Compressors
Chapter 7: Axial-Flow Compressors
Chapter 8: Radial-Inflow Turbines
Chapter 9: Axial-Flow Turbines
Chapter 10: Combustors
Overview...
(Read More)
Reciprocating compressors have the advantage over other types of compressors (i.e., centrifugal and rotary), when it comes to handling wide capacity swings and generating high head; thus they are...
(Read More)
Overview
As the preceding chapters showed, numerical and statistical methods can be used to identify areas of vulnerability before the analyst is actually confronted by the hardware and its...
(Read More)
|
|
