Sunday, June 25, 2017: 11:00 AM-12:30 PM
Fundamentals and Applications
Chair:
Christopher R. Laughman, Ph.D., Mitsubishi Electric Research Laboratories
Technical Committee: 1.13 Optimization
While optimization is often viewed as part of the design process for new systems, it can also provide significant value for improving existing systems. This session discusses the use of optimization techniques to improve existing systems, ranging in size from heat exchangers to buildings, to achieve higher performance without restarting the system design process from scratch.
1 Optimization of Small Diameter Tube-Fin Heat Exchangers to Enable Performance Improvements, Charge Reduction and Cost Savings
 |
Daniel Bacellar, University of Maryland |
While small diameter (≤5 mm) tube-fin heat exchangers have the potential to improve
performance, successful designs must meet many criteria. Three case studies are presented
to illustrate how optimization techniques can be used to design drop-in 5mm tube-fin
condenser replacements for a domestic refrigerator, a packaged terminal air conditioner, and a window
air conditioner that meet engineering and economic objectives. An optimization method is
applied to heat exchanger simulation tools to evaluate the performance of heat exchanger
simulations to identify optimal configurations that meet many objectives. Results
indicate that these designs can significantly enhance energy-efficiency, reduce
refrigerant charge, and reduce material consumption and cost.
performance, successful designs must meet many criteria. Three case studies are presented
to illustrate how optimization techniques can be used to design drop-in 5mm tube-fin
condenser replacements for a domestic refrigerator, a packaged terminal air conditioner, and a window
air conditioner that meet engineering and economic objectives. An optimization method is
applied to heat exchanger simulation tools to evaluate the performance of heat exchanger
simulations to identify optimal configurations that meet many objectives. Results
indicate that these designs can significantly enhance energy-efficiency, reduce
refrigerant charge, and reduce material consumption and cost.
2 Improving Heat Exchanger Circuitry by Using Derivative-Free Optimization
 |
Christopher R. Laughman, Ph.D., Mitsubishi Electric Research Laboratories |
While the interconnections between the tubes of a heat exchanger can have a significant
effect on its performance, this circuitry is difficult to design by hand because of the
large number of possible designs and the nonlinear and discontinuous dependence of the
performance on that circuitry. We formulate the circuitry design as a binary constrained
optimization problem, and apply derivative-free optimization (DFO) algorithms. We apply a
number of existing DFO algorithms to this problem, and demonstrate that they can find
optimal or near-optimal circuitry designs for realistic coil sizes after a limited number
of simulations.
effect on its performance, this circuitry is difficult to design by hand because of the
large number of possible designs and the nonlinear and discontinuous dependence of the
performance on that circuitry. We formulate the circuitry design as a binary constrained
optimization problem, and apply derivative-free optimization (DFO) algorithms. We apply a
number of existing DFO algorithms to this problem, and demonstrate that they can find
optimal or near-optimal circuitry designs for realistic coil sizes after a limited number
of simulations.
3 Optimizing Mini-Split Air Conditioning Units Using Alternative Refrigerants
 |
Bo Shen, Ph.D., ORNL |
Developments in the Montreal Protocol include the development of a global consensus
to phase-down the use of HFC refrigerants, as well as the continuing transition among
developing countries to phase-out the use of HCFC and introduce HFC as potential
intermediary solution. This presentation covers efforts to develop optimized system designs
for mini-split AC units used in developing and high ambient countries using alternative
lower global warming potential refrigerants. There are available
candidate refrigerants that can be introduced during the current phase-out transition in
order to eliminate a costly 2-step transition from HCFC to HFC and HFC to lower GWP
solutions.
to phase-down the use of HFC refrigerants, as well as the continuing transition among
developing countries to phase-out the use of HCFC and introduce HFC as potential
intermediary solution. This presentation covers efforts to develop optimized system designs
for mini-split AC units used in developing and high ambient countries using alternative
lower global warming potential refrigerants. There are available
candidate refrigerants that can be introduced during the current phase-out transition in
order to eliminate a costly 2-step transition from HCFC to HFC and HFC to lower GWP
solutions.
4 Operation Optimization of Buildings As Virtual Batteries for the Grid with High Penetrations of Renewables
 |
Zheng O'Neill, Ph.D., P.E., University of Alabama |
One approach for realizing the potential for both building energy cost savings and the
integration of renewable energy systems (RES) into the power grid involves the proactive
integration of building operation into the power grid by optimizing the operation of
energy sources with time-sensitive electricity price. The operation scheduling problem is
formulated with the RES, electrochemical batteries as energy sources, and the building
envelope as thermal energy storage, and is solved as a mixed integer programming problem.
A case study using the AMPL platform shows that such energy storage technologies provide
an effective way to connect energy supply resources and demands, and facilitate efficient
building operations.
integration of renewable energy systems (RES) into the power grid involves the proactive
integration of building operation into the power grid by optimizing the operation of
energy sources with time-sensitive electricity price. The operation scheduling problem is
formulated with the RES, electrochemical batteries as energy sources, and the building
envelope as thermal energy storage, and is solved as a mixed integer programming problem.
A case study using the AMPL platform shows that such energy storage technologies provide
an effective way to connect energy supply resources and demands, and facilitate efficient
building operations.