Heat Source Temperature Compensation During Chiller Staging
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Solution Overview
Problem
Existing heat source systems face challenges in maintaining a stable supply water temperature when the number of operating heat source machines changes, leading to deviations from the target temperature due to capability shortfalls and operational inefficiencies.
Innovation Solution
A heat source system that calculates a compensation temperature to adjust the cold/hot water outlet setting temperature of operational machines, anticipating flow rate changes when adding or subtracting machines, and sets the flow rate accordingly to maintain target supply water temperature, thereby stabilizing the water temperature supplied to the load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the set value of cold/hot water outlet temperature is lowered to suppress rise in supply water temperature, then the rise in supply water temperature is suppressed, but the supply water temperature may be excessively lowered and separated from target temperature
Solution Approach 1:
The system calculates and sets a compensation temperature in advance before the heat source machine is actually added or subtracted. This preliminary temperature adjustment ensures that when the machine count changes, the supply water temperature remains stable without excessive lowering or rising, resolving the contradiction between temperature stability and control accuracy.
Solution Approach 2:
The system continuously monitors the supply water temperature and adjusts the compensation temperature based on the actual temperature deviation from the target. This feedback mechanism ensures that the temperature control remains accurate while maintaining stability during machine count changes.
2Temperature
If the flow rate of refrigerator is increased to suppress rise in supply water temperature, then the rise in supply water temperature is suppressed, but the supply water temperature generally becomes higher than target temperature
Solution Approach 1:
The system calculates the compensation temperature in advance considering the anticipated flow rate changes when heat source machines are added or subtracted. This preliminary calculation ensures that the supply water temperature remains accurate to the target without becoming excessively high or low.
Solution Approach 2:
The system dynamically adjusts the compensation temperature parameter based on the number of operating heat source machines and their flow rates. By changing this parameter appropriately, the system maintains both temperature stability and control accuracy during operational transitions.
3Productivity
If heat source machine is added or subtracted to meet load demand, then the load capacity is adjusted, but the supply water temperature temporarily deviates from target temperature
Solution Approach 1:
Before adding or subtracting heat source machines, the system calculates a compensation temperature that anticipates the capability changes. This preliminary temperature adjustment ensures that when machines are added or subtracted to meet load demand, the supply water temperature remains stable and does not temporarily deviate from the target.
Solution Approach 2:
The system monitors supply water temperature in real-time and adjusts the compensation temperature based on feedback from actual temperature measurements, ensuring stability is maintained during load capacity adjustments.
Data Source
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AI summary
The purpose of the present invention is to maintain a water supply temperature close to a target water supply temperature at the time of a change in the number of heat source machines operating. A heat source system of the present invention anticipates a case where a prescribed minimum flow rate is set for heat source machines that are subject to addition or removal, and calculates, as compensation temperatures, hot and cold water outlet temperatures of the heat source machines so that the water supply temperature in such a case will match a target water supply temperature (SA2), and changes the hot and cold water outlet temperature settings of the operating heat source machines to the compensation temperatures (SA4). After that, the heat source machines that are subject to addition or removal are either started up or stopped (SA6), and the set flow rate for the heat source machines that are subject to addition or removal is set to the minimum flow rate (SA7).