Hot Water Appliance Parallel Pipe Circulation Pump Control
Solution Overview
Problem
Domestic hot water systems often waste resources and provide unstable temperatures, leading to long wait times for hot water and potential overheating, especially in summer months, due to inefficiencies in water preheating and pressure management.
Innovation Solution
A hot water system with a circulation pump in the heat exchange line, a flow sensor, and an electrically actuated valve, controlled by a controller that activates the pump in boost mode and manages valve operation to ensure stable pressure and temperature, preventing overheating by deactivating the pump when a threshold is reached.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a water pump is mounted only in the water preheating circuit, then water can be preheated before use, but the pump cannot provide domestic hot water at water consuming points when needed
Solution Approach 1:
The circulation pump is designed to perform multiple functions: it can operate in normal mode to circulate water through the heat exchange line for preheating, and in boost mode to provide domestic hot water at water consuming points by drawing from the hot water tank. This multi-functionality resolves the contradiction between productivity and adaptability.
Solution Approach 2:
The system dynamically switches between normal mode and boost mode based on demand. The controller activates the pump in boost mode when hot water is needed at consuming points, and in normal mode during preheating cycles. This dynamic operation allows the pump to adapt to different operational requirements.
2Loss of time
If the circulation pump operates continuously to preheat water, then hot water is readily available, but energy is wasted when hot water is not needed
Solution Approach 1:
The circulation pump operates periodically rather than continuously. The controller manages preheating cycles by activating the pump at intervals to circulate water through the heat exchange line, then deactivating it when the tank reaches the preset temperature. This periodic operation reduces energy waste while maintaining hot water availability.
Solution Approach 2:
The system uses temperature sensors to monitor water temperature in the heat exchange line and hot water tank. When the preset temperature is reached, the controller deactivates the pump. This feedback mechanism prevents unnecessary energy consumption while ensuring hot water is ready when needed.
3Loss of energy
If the water pump is deactivated when preset temperature is reached, then energy is saved, but hot water supply may be interrupted when needed
Solution Approach 1:
The system performs preliminary preheating of water in the heat exchange line and hot water tank before it is actually needed. By continuously maintaining a supply of preheated water, the system ensures that when the pump is deactivated due to reaching preset temperature, hot water is still readily available for immediate use, thus maintaining reliability while saving energy.
4Loss of time
If the water pump operates in boost mode to provide instant hot water, then hot water is immediately available at consuming points, but water pressure stability may be affected
Solution Approach 1:
The boost mode provides excessive action by delivering a high volume of hot water quickly to the consuming point. This partial activation of the pump's full capacity is sufficient to meet immediate hot water demand without requiring continuous high-pressure operation, thus maintaining overall pressure stability while providing instant hot water.
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
Enables instant hot water supply at domestic points with stable temperatures, reducing user discomfort and resource waste by maintaining preset outlet temperatures and ensuring consistent water pressure.
Implementation Method 1
a heat exchange line for allowing water passing therethrough to absorb heat generated by the heat source
Implementation Method 2
A circulation pump is disposed in the heat exchange line
Data Source
Figure 1
Figure 2
AI summary
The present invention discloses a hot water appliance including a housing, a heat source, and a hydraulic assembly. The housing has a first water inlet port, a second water inlet port, and a water outlet port. The heat source is disposed in the housing. The hydraulic assembly is disposed in the housing and including a heat exchange line for allowing water passing therethrough to absorb heat generated by the heat source, a first pipe section connected with the first water inlet port and communicating with the heat exchange line, and a second pipe section connected with the second water inlet port and communicating with the heat exchange line, wherein the first pipe section and the second pipe section are arranged in parallel. A circulation pump is disposed in the heat exchange line. A flow sensor is disposed in the first pipe section. An electrically actuated valve is provided in the second pipe section. Since the circulation pump is disposed in the heat exchange line, the stability of the pressure of cold water supplied can be assured.