ASHRAE Journal - November 2013 - 14
Technical feaTure
fea
industrial Refrigeration systems
Sequencing & Control
Of Compressors
By Douglas T. ReinDl, Ph.D., P.e., Fellow ashRae
Virtually every built-up refrigeration system used in commercial or industrial
applications has multiple compressors available for operation to meet loads.
One of the challenges in designing and operating a system with multiple
compressors is deciding how best to sequence their controls to meet variable
refrigeration loads while avoiding inefficient compressor performance at
part-load to maintain high system efficiency.
This article discusses typical part-load efficiency characteristics for screw and reciprocating compressors
commonly found in built-up industrial refrigeration
systems. It includes recommendations for sequencing and control strategies that enable efficient system
operation.
Introduction
Industrial refrigeration systems come in all different
sizes, configurations, and arrangements. The nature
of the food production and storage facilities this technology most frequently calls "home" are quite varied,
and nearly all of the refrigeration systems installed in
these applications are custom-engineered to meet the
specific thermal requirements of loads within the facility. Individual owners establish specific requirements
for their refrigeration infrastructure, and the relative
importance of these requirements vary on a plant-byplant basis. The requirements can be grouped into two
categories "non-negotiable" and "negotiable."
Non-negotiable requirements dictate that the refrigeration system must be: safe and able to meet the magnitude and temperature requirements of coincident
load(s). Safety is achieved by ensuring the systems are
designed, constructed, and operated in accordance with
the latest applicable standards, codes, regulations, and
industry best practices. Guaranteeing the refrigeration
system can reliably meet its loads requires appropriate sizing of key components including compressors. In
some cases, achieving the ability to reliably meet loads
may necessitate redundant compressors. Negotiable
requirements can include capital cost, operating costs,
About the Author Douglas T. Reindl, Ph.D., P.E., is a professor and director at the University of Wisconsin-Madison's Industrial Refrigeration Consortium in Madison, Wis.
14
ASHRAE JouRnAl
ashrae.org
N ovem ber 2013
ASHRAE Journal - November 2013
Table of Contents for the Digital Edition of ASHRAE Journal - November 2013
Contents
Commentary
Industry News
Letters
Meetings and Shows
Feature Articles
Sequencing & Control of Compressors
Fire Station Renovation
Sewage Plant Heats Village
Standing Columns
Engineer’s Notebook
Building Sciences
Special Supplement
BACnet Today & the Smart Grid
The Performance Gap
Refrigeration Applications
InfoCenter
Energy Modeling
Emerging Technologies
Data Centers
People
Products
Special Products
Geothermal for Big Box Retail
Classified Advertising
Advertisers Index
ASHRAE Journal - November 2013 - Intro
ASHRAE Journal - November 2013 - Cover1
ASHRAE Journal - November 2013 - Cover2
ASHRAE Journal - November 2013 - 1
ASHRAE Journal - November 2013 - 2
ASHRAE Journal - November 2013 - Contents
ASHRAE Journal - November 2013 - Commentary
ASHRAE Journal - November 2013 - 5
ASHRAE Journal - November 2013 - Industry News
ASHRAE Journal - November 2013 - 7
ASHRAE Journal - November 2013 - 8
ASHRAE Journal - November 2013 - 9
ASHRAE Journal - November 2013 - Letters
ASHRAE Journal - November 2013 - 11
ASHRAE Journal - November 2013 - Meetings and Shows
ASHRAE Journal - November 2013 - 13
ASHRAE Journal - November 2013 - Sequencing & Control of Compressors
ASHRAE Journal - November 2013 - 15
ASHRAE Journal - November 2013 - 16
ASHRAE Journal - November 2013 - 17
ASHRAE Journal - November 2013 - 18
ASHRAE Journal - November 2013 - 19
ASHRAE Journal - November 2013 - 20
ASHRAE Journal - November 2013 - 21
ASHRAE Journal - November 2013 - 22
ASHRAE Journal - November 2013 - 23
ASHRAE Journal - November 2013 - 24
ASHRAE Journal - November 2013 - 25
ASHRAE Journal - November 2013 - 26
ASHRAE Journal - November 2013 - 27
ASHRAE Journal - November 2013 - 28
ASHRAE Journal - November 2013 - 29
ASHRAE Journal - November 2013 - Fire Station Renovation
ASHRAE Journal - November 2013 - 31
ASHRAE Journal - November 2013 - 32
ASHRAE Journal - November 2013 - 33
ASHRAE Journal - November 2013 - 34
ASHRAE Journal - November 2013 - 35
ASHRAE Journal - November 2013 - 36
ASHRAE Journal - November 2013 - 37
ASHRAE Journal - November 2013 - 38
ASHRAE Journal - November 2013 - 39
ASHRAE Journal - November 2013 - Sewage Plant Heats Village
ASHRAE Journal - November 2013 - 41
ASHRAE Journal - November 2013 - 42
ASHRAE Journal - November 2013 - 43
ASHRAE Journal - November 2013 - 44
ASHRAE Journal - November 2013 - 45
ASHRAE Journal - November 2013 - 46
ASHRAE Journal - November 2013 - 47
ASHRAE Journal - November 2013 - Engineer’s Notebook
ASHRAE Journal - November 2013 - 49
ASHRAE Journal - November 2013 - 50
ASHRAE Journal - November 2013 - 51
ASHRAE Journal - November 2013 - 52
ASHRAE Journal - November 2013 - 53
ASHRAE Journal - November 2013 - 54
ASHRAE Journal - November 2013 - 55
ASHRAE Journal - November 2013 - Building Sciences
ASHRAE Journal - November 2013 - 57
ASHRAE Journal - November 2013 - 58
ASHRAE Journal - November 2013 - 59
ASHRAE Journal - November 2013 - 60
ASHRAE Journal - November 2013 - 61
ASHRAE Journal - November 2013 - 62
ASHRAE Journal - November 2013 - 63
ASHRAE Journal - November 2013 - 64
ASHRAE Journal - November 2013 - BACnet Today & the Smart Grid
ASHRAE Journal - November 2013 - BCover2
ASHRAE Journal - November 2013 - B1
ASHRAE Journal - November 2013 - B2
ASHRAE Journal - November 2013 - B3
ASHRAE Journal - November 2013 - B4
ASHRAE Journal - November 2013 - B5
ASHRAE Journal - November 2013 - B6
ASHRAE Journal - November 2013 - B7
ASHRAE Journal - November 2013 - B8
ASHRAE Journal - November 2013 - B9
ASHRAE Journal - November 2013 - B10
ASHRAE Journal - November 2013 - B11
ASHRAE Journal - November 2013 - B12
ASHRAE Journal - November 2013 - B13
ASHRAE Journal - November 2013 - B14
ASHRAE Journal - November 2013 - B15
ASHRAE Journal - November 2013 - B16
ASHRAE Journal - November 2013 - B17
ASHRAE Journal - November 2013 - B18
ASHRAE Journal - November 2013 - B19
ASHRAE Journal - November 2013 - B20
ASHRAE Journal - November 2013 - B21
ASHRAE Journal - November 2013 - B22
ASHRAE Journal - November 2013 - B23
ASHRAE Journal - November 2013 - B24
ASHRAE Journal - November 2013 - B25
ASHRAE Journal - November 2013 - B26
ASHRAE Journal - November 2013 - B27
ASHRAE Journal - November 2013 - B28
ASHRAE Journal - November 2013 - B29
ASHRAE Journal - November 2013 - B30
ASHRAE Journal - November 2013 - The Performance Gap
ASHRAE Journal - November 2013 - 66
ASHRAE Journal - November 2013 - 67
ASHRAE Journal - November 2013 - 68
ASHRAE Journal - November 2013 - 69
ASHRAE Journal - November 2013 - 70
ASHRAE Journal - November 2013 - 71
ASHRAE Journal - November 2013 - 72
ASHRAE Journal - November 2013 - Refrigeration Applications
ASHRAE Journal - November 2013 - InfoCenter
ASHRAE Journal - November 2013 - 75
ASHRAE Journal - November 2013 - 76
ASHRAE Journal - November 2013 - 77
ASHRAE Journal - November 2013 - 78
ASHRAE Journal - November 2013 - Energy Modeling
ASHRAE Journal - November 2013 - Emerging Technologies
ASHRAE Journal - November 2013 - 81
ASHRAE Journal - November 2013 - 82
ASHRAE Journal - November 2013 - 83
ASHRAE Journal - November 2013 - Data Centers
ASHRAE Journal - November 2013 - 85
ASHRAE Journal - November 2013 - 86
ASHRAE Journal - November 2013 - People
ASHRAE Journal - November 2013 - Products
ASHRAE Journal - November 2013 - Special Products
ASHRAE Journal - November 2013 - Geothermal for Big Box Retail
ASHRAE Journal - November 2013 - 91
ASHRAE Journal - November 2013 - 92
ASHRAE Journal - November 2013 - 93
ASHRAE Journal - November 2013 - 94
ASHRAE Journal - November 2013 - Classified Advertising
ASHRAE Journal - November 2013 - Advertisers Index
ASHRAE Journal - November 2013 - Cover3
ASHRAE Journal - November 2013 - Cover4
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