Optimization of the Water-Cooled Chiller Plant System Operation

A300CAW ACADEMIC WRITING SKILLS 3 (AWS3)
How the performance of a chiller optimized? Are the buildings in Singapore subject to a
standardized grading?
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Table of Content
1. Abstract
2. Justification
3. Why the optimization of chiller performance is important?
4. Chiller Control Process
4.1 Technique and Methodologies for Performance Optimization
4.1.1 Variable Speed Design Strategy
4.1.2 Maximizing High Chilled Water Δ T (Delta)
5. Standard Grading Systems
5.1 Comparison of Standard Grading Systems with Singapore Standards
6. Case Study
7. Conclusion
8. Recommendations
9. References
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1. Abstract
Maintaining and managing optimal energy efficiency in a building is a huge challenge
that all engineers in Building Automation Systems (BAS) and Heating, Ventilation and Air
Conditioning (HVAC) industry work extremely hard to overcome. Chiller plant consumes the
majority of energy consumption in a building thus it is vital to optimize the performance of the
chiller plant and achieve desired thermal comfort at the same time. This report looks into the
technique and methodologies of chiller plant performance optimization and common challenges
that arise during the implementation of the optimization process. It also explores the standard
international standards of chiller optimization and compares that with current approaches in
Singapore buildings and concludes with recommendations to close necessary gaps in
standardizations.
2. Justification
As a Building Automation Engineer in this industry, this topic is very interested in me
since it plays a significant role in saving energy in a building. At the same time, I am concerned
about the global green building concept, which enhances the sustainability and efficiency of a
building (Burrows, 2017). A chiller plant consumes a huge amount of energy thus optimization
of chiller is very important since energy costs a lot of money as well as huge environmental
impacts as energy is mostly produced by using natural resources. Thus this research report would
address the importance of chiller optimization and different kind of methods and technique to
achieve standard grading in a building to save energy consumption.
3. Why the optimization of chiller performance is important?
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Chiller plant is often considered the "heart" of a building's HVAC system, thus it is
massively important to optimize the chiller plant in order to achieve the improved building
performance (Taylor, 2010). Not only is the chiller plant the main source of cooling, but also its
power requirements make up a large amount of a building's energy needs. For an example, the
HVAC system can equal an average of 60 per cent of the total electrical load in a building and
plant represents a major portion of that HVAC load.
According to Energy Information Administration, DC, USA, (2003), "The building sector
is responsible for a significant share of energy-related carbon emissions across the world".
Greenhouse Gases (GHG) in the atmosphere block radiated heat returning from earth surface,
which would lead to global warming and various climate changes. Water vapors (H2O), Carbon
dioxide (CO2), Methane (CH4) and Chlorofluorocarbons (CFC) are some of the major GHGs
that could be found during the operation of a chiller plant. By optimizing a chiller plant it is
viable to reduce the emission of those Greenhouse Gases and achieve the Global Green Building
status (Bell, 2013).
In an optimized chiller system condenser water pumps, chilled water pumps and cooling
tower fans are often controlled by Variable Speed Drives (VSD) and they run according to
required speed calculated by different designed set points. So such equipment does not function
at a constant speed or maximum speed for a long time and it will lead to have a higher life
expectancy for equipment and reduce the ratio of breakdowns in the plant. Thus this would lead
to having a more reliable system with higher durability (Le, 2018). The diagram below
illustrates the chiller;
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