Tank Level Setpoint Control for Water Demand and Heat Loss
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Solution Overview
Problem
Water dispensers face challenges in balancing energy efficiency and water supply, as larger tanks reduce heat loss but may not meet increasing demand for hot or chilled water, leading to insufficient water availability.
Innovation Solution
A method of controlling liquid levels in a tank by setting a setpoint and monitoring levels, adjusting the setpoint and monitoring levels based on actual usage patterns to optimize water storage and reduce energy consumption while ensuring adequate supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a larger tank is used to store more water, then water availability is improved, but energy loss increases due to larger surface area for heat transfer
Solution Approach 1:
The patent applies dynamics by making the setpoint level adjustable based on observed demand patterns. The system transitions from a static tank size design to a dynamic control approach where the effective storage volume (setpoint) adapts over time. This resolves the contradiction by allowing the system to use smaller effective storage (reducing heat loss) when demand is low, while maintaining adequate water availability when demand increases, without requiring physical tank modification.
2Loss of energy
If a smaller tank is used to reduce energy loss, then energy efficiency is improved, but water availability deteriorates when demand increases
Solution Approach 1:
The system applies self-service by automatically observing water removal patterns and autonomously adjusting the setpoint level without user intervention. The controller monitors consumption over time and dynamically modifies the setpoint to match actual demand, ensuring water availability adapts to usage patterns while minimizing energy loss. This eliminates the need for users to manually adjust tank size or setpoint based on changing demand.
Solution Approach 2:
The patent implements feedback by continuously monitoring water removal volume and using this information to adjust the setpoint level. The system measures actual consumption patterns and feeds this information back to the controller, which then modifies the setpoint accordingly. This closed-loop control resolves the contradiction by ensuring the tank maintains adequate water levels based on actual demand while minimizing excess storage that would increase heat loss.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach optimizes energy use by adjusting the setpoint and monitoring levels in response to demand fluctuations, maintaining an adequate water supply while minimizing energy loss and tank size, applicable to both hot and chilled water dispensers.
Implementation Method 1
Water is heated by an electrical element 6
Implementation Method 2
the temperature of the water measured with a temperature probe 7
Implementation Method 3
a solenoid valve 5... control operation of the element 6 and solenoid filling valve 5
Implementation Method 4
measurement of liquid level may be carried out by measuring the electrical resistance between electrically-isolated metal studs 8
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Level Control A method of controlling the level of a liquid in a tank in the face of intermittent liquid removal by periodically reviewing the setpoint of a level controller in light of the lowest liquid level in the tank during a preceding time window. If the level has not fallen below a first set datum, the setpoint is decreased. However, if the level has fallen below a second, lower datum, the setpoint is increased. Otherwise, the setpoint remains unchanged. Figure 6 should accompany the abstract.