Solar Collector Pump Control Using Outlet Temperature Rise
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Solution Overview
Problem
Conventional solar controls face imprecision in temperature measurement, leading to premature or delayed switching of the solar charging pump, affecting energy efficiency due to reliance on combined medium and chassis temperature readings and selective sensor placements.
Innovation Solution
A solar control system where the solar charging pump is switched off after a preset time, with the temperature measured by a single sensor at the hot water outlet, and switched on when the temperature rises above a predetermined threshold, using a timer to set the pump runtime and saving the last temperature value as the minimum, independent of temperature profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional temperature difference control with multiple sensors is used, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts the temperature measurement function from multiple sensors to a single sensor positioned at the hot water outlet. By removing unnecessary sensors and simplifying the measurement system to one strategic location, the patent achieves adequate temperature control without the complexity of multiple sensor arrangements while maintaining acceptable measurement precision for pump control decisions.
Solution Approach 2:
The single temperature sensor at the hot water outlet serves multiple functions: it measures the actual outlet temperature, determines when to switch the pump on/off, and provides the basis for calculating temperature differences. This multi-functional use of one sensor reduces device complexity while maintaining the essential measurement capabilities needed for solar system control.
2Device complexity
If pump switching is based on selective temperature measurements, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent positions the temperature sensor at the hot water outlet where it directly measures the actual outlet temperature before the fluid enters the storage tank. This preliminary measurement at the critical location ensures accurate detection of temperature conditions for pump control, preventing both premature and delayed pump switching while using only a single sensor.
3Loss of energy
If pump running time is extended to improve energy transfer, then energy efficiency is improved, but loss of time increases
Solution Approach 1:
The patent uses continuous temperature measurement at the hot water outlet to provide feedback on actual thermal conditions. The controller monitors the temperature and automatically adjusts pump running time based on real-time conditions, extending pump operation when energy transfer is needed and reducing it when sufficient temperature difference exists, thereby optimizing both energy efficiency and time utilization.
Solution Approach 2:
The pump running time is made dynamic rather than fixed. The system continuously adapts the pump operation duration based on measured temperature conditions, allowing the pump to run longer when energy transfer efficiency requires it and shorter when temperature conditions are already favorable, thus balancing energy efficiency with time 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
Ensures optimal energy transfer with reduced complexity and cost, as the system remains efficient regardless of sensor placement or changes in the heat exchanger, maintaining energy efficiency without the need for extensive measurement equipment.
Implementation Method 1
the temperature is determined by a temperature sensor provided in the hot water outlet of the solar collector
Implementation Method 2
The heated flow medium flows via the hot water outlet 2 to the heat exchanger 6 and transfers its thermal energy to the solar storage tank 7 there
Data Source
Figure 1~2
AI summary
The invention relates to a solar control system for a solar thermal system comprising a solar collector, a cold water inlet, a hot water outlet, and a solar charging pump in the cold water inlet, characterized in that a temperature sensor (4) and a timer are provided for controlling the solar charging pump (5) on the solar collector (1) in the hot water outlet (2), and that the pump (5) is switched off after a preset pump running time, the temperature change is determined by the temperature sensor (4), and the pump (5) is switched on again when the temperature rises or remains switched off when the temperature falls, until a temperature rise is measured again from a stored minimum temperature value (10) and the pump (5) is switched on.