Engine-Drive Cooling Technology
Engine-driven chillers operate in a manner similar to electric chillers, substituting a natural gas engine for the electric motor to drive a reciprocating, rotary screw or centrifugal compressor. The efficiency of the natural gas engine combined with the opportunity to recover engine and exhaust heat to produce domestic hot water and for other thermal energy needs contribute to the high-efficiency of these systems.
Engine-driven chillers can be driven by any type of engine, depending upon the compressor design. Typically, one of three types of compressors are used:
- Reciprocating compressors – smaller applications of 200 tons or less
- Screw compressors (single or twin) – applications ranging from 100 to 1,250 tons
- Centrifugal compressors (single or multiple stage) – applications ranging from 100 to 8,000 tons (28,000 kW)
Natural gas engines working in tandem with steam turbines can power chillers in central plants with cooling capacities of a few hundred to a few thousand tons. Larger, heavy-duty equipment is also available to meet cold storage and process needs of commercial and industrial users.