Water Heater Mixed Capacity Estimation Using Multi-Zone Temperature Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for estimating the mixed water capacity in water heaters lack accuracy, particularly at predetermined use temperatures, such as 40°C, due to limitations in temperature measurement and calculation methods.
Innovation Solution
A method and device that measure heated and cold water temperatures using multiple probes, with a microcontroller calculating mixed water capacity by defining functions as segments of straight lines based on temperature differences, allowing for improved accuracy and real-time estimation of available hot water volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single longitudinal temperature sensor is used to estimate hot water volume, then the device complexity is reduced, but the measurement precision of mixed water capacity deteriorates
Solution Approach 1:
The water heater tank is divided into multiple thermal zones (typically three zones: top, middle, bottom) with separate temperature sensors in each zone. This segmentation allows independent measurement of temperature gradients throughout the tank, enabling more accurate calculation of mixed water capacity at predetermined temperatures by accounting for thermal stratification effects in each zone.
Solution Approach 2:
The invention transitions from a single-point temperature measurement approach to a multi-dimensional temperature field measurement by placing sensors at different vertical positions and depths within the tank. This spatial distribution of sensors captures the three-dimensional thermal structure of the water, allowing for precise estimation of available hot water volume through integrated thermal mass calculation.
2Device complexity
If cold water temperature is stored in memory and not continuously updated, then the device complexity is reduced, but the reliability of mixed water capacity calculation deteriorates when water temperature nears cold water temperature
Solution Approach 1:
The system dynamically adjusts the cold water temperature reference value based on operating conditions. When the measured water temperature in the tank approaches the stored cold water temperature, the system activates an update mechanism that refreshes the cold water temperature from the memory storage. This dynamic updating ensures the reference temperature remains accurate throughout the heating cycle, maintaining calculation reliability across all temperature differentials.
Solution Approach 2:
The system implements a feedback mechanism where the measured water temperature is continuously compared against the stored cold water temperature. When the difference between these temperatures falls below a predetermined threshold, the feedback loop triggers an update of the cold water temperature value from memory, ensuring the reference parameter remains valid and improving the accuracy of mixed water capacity calculations under low temperature differential conditions.
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
Enhances the accuracy of mixed water capacity estimation at predetermined temperatures, enabling precise user feedback and optimizing heating periods by accounting for thermal gradients and mixing effects within the water heater.
Implementation Method 1
measuring at least one heated water temperature (2) using at least one corresponding measuring means (2a, 2b)
Data Source
Figure 1~2
Figure 3
AI summary
A method for determining a mixed water capacity at a predetermined use temperature, comprises a step (101) of measuring a heated water temperature, a step (106) of estimating the capacity of mixed water as a function of a heated water temperature measured in the previous step, a step of using a cold water temperature (103, 104) entering the water heater and possibly the setpoint temperature chosen (100) to parameterize (105) a function for calculating said mixed water capacity as a function of a heated water temperature. Application to devices for determining a mixed water capacity at a predetermined operating temperature.