Energy Consumption Analysis for a Single Screw Extruder - Intelligent Computing for Sustainable Energy and Environment - page 539

Ta b l e 3 . Effects of water cooling temperature settings on the energy consumption (data was
recorded for 50 minutes, the sampling rate was 10Hz)

DOE D DOE C DOE E

Water cooling temperature low medium high

Total thermal energy (kwh) 1.020 1.000 0.961

Extruder active energy (kwh) 1.403 1.381 1.345

Motor drive active energy (kwh) 0.435 0.431 0.427

Extruder power factor 0.616 0.612 0.606

Motor drive power factor 0.408 0.406 0.405

Zone 1 vs total thermal 0.667 0.657 0.644

Total SEC (kwh/kg) 0.772 0.757 0.736

Thermal SEC (kwh/kg) 0.561 0.548 0.525

Motor SEC (kwh/kg) 0.239 0.236 0.234

4.3 Screw Speed

There is no doubt that higher screw speed leads to lower energy consumption. Accord-
ing to the results in table 4, screw speed has the most significant impact on thermal
specific energy consumption (SEC). By contrast, the screw speed has small effect on
the motor SEC. A small decrease on power factor can also be observed as the screw
speed increased. However, the melt quality at higher screw speed need to be further
investigated.

Ta b l e 4 . Effects of screw speed on the energy consumption (data was recorded for 50 minutes,
the sampling rate was 10Hz)

DOE F DOE C DOE G

Screw speed 20 40 60

Total thermal energy (kwh) 0.994 1.000 1.048

Extruder active energy (kwh) 1.185 1.381 1.626

Motor drive active energy (kwh) 0.224 0.431 0.624

Extruder power factor 0.640 0.612 0.637

Motor drive power factor 0.301 0.406 0.500

Zone 1 vs total thermal 0.630 0.657 0.695

Total SEC (kwh/kg) 1.325 0.757 0.583

Thermal SEC (kwh/kg) 1.111 0.548 0.376

Motor SEC (kwh/kg) 0.251 0.236 0.234

5 Conclusions and Future Works

Simple and efficient energy monitoring methods have been developed in this paper. The
new methods can not only monitor the thermal energy usage profile along the extruder,
but also provide accurate and reliable monitoring of both thermal energy and motor
drive energy consumption independent of extruder geometry and material. The effects
of barrel temperature settings, water cooling, and screw speed on energy efficiency were