Chiller Sequencing Control for System-Wide COP Optimization
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Solution Overview
Problem
Existing chiller control systems cannot optimize the efficiency of the entire chiller system, as they primarily focus on individual chiller optimization rather than system-wide optimization, and fail to adapt efficiently to varying load conditions and chiller characteristics.
Innovation Solution
A chiller control apparatus that includes a chiller determination unit capable of selecting the most efficient chiller for stage increase or decrease based on conditions, using a stage increase operation pattern extraction unit, chiller-to-be-operated selection unit, stage decrease operation pattern extraction unit, and chiller-to-be-stopped selection unit, which calculate efficiency index values and operation times to optimize the number of operating chillers and select the appropriate chillers for efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If individual chiller optimization is performed, then individual chiller efficiency is improved, but system-wide efficiency optimization cannot be achieved
Solution Approach 1:
The patent merges individual chiller optimization with system-wide optimization by integrating multiple chiller performance evaluations into a unified control system. The controller calculates efficiency indices for each chiller and determines optimal operating patterns that maximize overall system efficiency rather than just individual unit performance.
Solution Approach 2:
The system changes operational parameters dynamically by adjusting the number of operating chillers and their respective load distributions based on real-time efficiency calculations. The controller modifies operating conditions to transition from static individual optimization to dynamic system-wide optimization.
2Quantity of substance
If the number of operating chillers is increased, then system capacity is improved, but system efficiency may deteriorate
Solution Approach 1:
The patent implements dynamic adjustment of the number of operating chillers based on real-time efficiency evaluations. The controller continuously monitors system conditions and dynamically determines the optimal number of chillers to operate, transitioning from fixed capacity configurations to adaptive capacity management that maintains efficiency while meeting demand.
Solution Approach 2:
The system dynamically changes operational parameters including the number of active chillers and their load distributions. By adjusting these parameters based on calculated efficiency indices, the system optimizes the balance between capacity and efficiency rather than operating at fixed settings.
3Ease of operation
If chiller operation patterns are fixed, then control simplicity is maintained, but adaptability to varying load conditions deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where the controller continuously evaluates chiller efficiency indices and uses this information to determine optimal operating patterns. The system receives feedback on actual performance and adjusts operating decisions accordingly, transitioning from open-loop fixed control to closed-loop adaptive control.
Solution Approach 2:
The system transitions from static fixed operation patterns to dynamic adaptive patterns that respond to changing load conditions. The controller dynamically determines which chillers to operate and at what loads based on real-time efficiency calculations, enabling adaptability while maintaining automated simplicity.
4Quantity of substance
If all chillers operate at maximum capacity, then system capacity is maximized, but overall efficiency deteriorates
Solution Approach 1:
The patent changes operational parameters by adjusting chiller load distributions rather than operating all units at maximum capacity. The controller calculates optimal load allocations based on individual chiller efficiency characteristics, distributing the total system load to maximize overall efficiency while maintaining required capacity.
Solution Approach 2:
The system applies local quality optimization by tailoring the operating load of each individual chiller to its specific efficiency characteristics. Rather than uniform maximum operation, each chiller operates at an optimized load point that maximizes its contribution to overall system efficiency while meeting total demand requirements.
Data Source
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AI summary
A chiller control apparatus increases or decreases chillers in order to efficiently operate an entire chiller system. When the number of chillers increases, an insufficient load value calculation unit calculates an insufficient amount of a load for a required load. Then, using a COP obtained according to an operating environment of the chiller, a chiller-to-be-operated selection unit selects, from among stopped chillers, a chiller having the highest COP when operated with an insufficient amount of a load, as the chiller to be subjected to stage increase. Further, when the number of chillers decreases, an operation pattern extraction unit extracts operation patterns that are combinations of chillers to be operated according to the required load. Then, a chiller-to-be-stopped selection unit obtains a COP of the entire chiller system for each operation pattern, using the COP obtained according to the operating environment of the chiller, and selects a chiller subjected to stage decrease based on the operation pattern corresponding to the highest COP.