Storage-type hot water supply device
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Solution Overview
Problem
Existing storage-type hot water supply devices face inaccuracies in estimating the accumulated heat amount due to low temperature sensor accuracy, which can be costly to improve with high-accuracy sensors.
Innovation Solution
The device equalizes water temperatures within the storage tank using a control system, allowing temperature sensors to detect uniform temperatures and identify abnormal sensors, enabling accurate estimation of the heat distribution and amount.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high accuracy temperature sensors are installed to improve temperature detection accuracy, then measurement precision is improved, but device cost increases
Solution Approach 1:
The system performs a preliminary equalization operation before normal operation to establish a reference state where all temperature sensors should detect the same temperature. This preliminary calibration allows the system to verify sensor accuracy without requiring expensive high-precision sensors from the start.
Solution Approach 2:
The control means compares temperature readings from multiple sensors during the equalization state to identify abnormal sensors. This feedback mechanism allows the system to detect and compensate for sensor inaccuracies, maintaining measurement precision without requiring all sensors to be high-precision types.
2Measurement precision
If multiple temperature sensors are used to estimate temperature distribution, then measurement coverage is improved, but reliability deteriorates due to sensor accuracy issues
Solution Approach 1:
The system uses itself to verify sensor accuracy by comparing readings from multiple sensors during the equalization state. Each sensor's reading is cross-checked against others when they should all detect the same temperature, allowing the system to self-diagnose and identify unreliable sensors without external calibration equipment.
Solution Approach 2:
The system changes the operational parameter from normal stratified storage to an equalization state temporarily. This parameter change allows all sensors to detect the same temperature value, creating a unique calibration condition that reveals sensor accuracy issues that would be hidden during normal operation with temperature gradients.
Data Source
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AI summary
A circulation pump (103) supplies to a heat pump unit (200) hot water obtained from a lower portion of a hot-water storage tank (101). The heat pump unit (200) generates high-temperature hot water by heating the supplied hot water. The tank (101) stores hot water having different temperature zones by receiving the high-temperature hot water from an upper portion. A temperature sensor (102a to 102f) detects the temperature of the hot water stored in the tank (101). A control device (300) causes equalization of the temperature of the stored hot water by causing hot water supplied from the circulation pump (103) to circulate through the tank (101). In a state in which the temperatures of the hot water are equalized, the control device (300) provides a notification of a temperature sensor (102a to 102f) that, among the temperature sensors (102a to 102f), detects an abnormal temperature.