Method for providing a secondary medium
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Solution Overview
Problem
Existing systems for heating secondary media, such as drinking water, with a primary medium in buildings often result in temperature fluctuations and the risk of scalding due to inefficient heat exchanger designs and lack of precise temperature control, especially when hot water is not continuously used.
Innovation Solution
A control system comprising a main heat exchanger and a control heat exchanger arranged in series, with a throttle and actuator system that maintains a stable temperature by regulating the flow of primary medium based on temperature measurements from both media, ensuring the secondary medium is heated to a consistent temperature without overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a single heat exchanger is used to heat secondary medium with primary medium, then heat transfer efficiency is improved, but temperature control precision deteriorates leading to temperature peaks and scalding risk
Solution Approach 1:
The single heat exchanger is divided into two separate heat exchangers: a first heat exchanger for efficient heat transfer from primary to secondary medium, and a second heat exchanger for precise temperature control by mixing hot and cold secondary medium. This segmentation allows each component to specialize in one function, resolving the contradiction between heat transfer efficiency and temperature control precision.
Solution Approach 2:
Cold secondary medium is introduced as an intermediary substance in the second heat exchanger to actively control and reduce the temperature of hot secondary medium. This intermediary enables precise temperature regulation without compromising the overall heat transfer efficiency of the system.
2Loss of energy
If primary medium flow is continuously regulated to match secondary medium demand, then energy consumption is reduced, but temperature stability deteriorates causing temperature drops during tapping
Solution Approach 1:
The system pre-heats the secondary medium in the first heat exchanger to a temperature higher than the final desired temperature, and stores this hot secondary medium ready for use. When tapping occurs, the pre-prepared hot medium is immediately available, eliminating temperature delays and ensuring stability while allowing energy-efficient operation during non-tapping periods.
Solution Approach 2:
The first heat exchanger continuously operates to maintain a reservoir of pre-heated secondary medium, ensuring that hot water is always available immediately when needed. This continuous preparation eliminates the harmful temperature drops that occur with intermittent heating, while the system overall remains energy-efficient by avoiding excessive heating.
3Quantity of substance
If heat exchanger volume is increased to provide sufficient hot water, then hot water availability is improved, but heat exchanger overheating worsens when tap is closed
Solution Approach 1:
The heat exchanger system is segmented into two units with different functions: the first heat exchanger is optimized for heat transfer efficiency with smaller volume, while the second heat exchanger handles temperature regulation. This segmentation allows the system to provide sufficient hot water without requiring one large heat exchanger that would overheat when not in use.
Solution Approach 2:
The system changes the temperature parameter of the secondary medium by introducing cold secondary medium into the second heat exchanger. This allows the first heat exchanger to operate at optimal temperatures without overheating, while still providing sufficient quantities of hot water by efficiently regulating the mixing process in the second heat exchanger.
4Measurement precision
If complex control system with multiple sensors and actuators is implemented, then temperature control precision is improved, but device complexity increases
Solution Approach 1:
The control system utilizes the inherent thermal properties of the fluids and the natural heat exchange processes to achieve temperature control. The system self-regulates by leveraging the temperature difference between primary and secondary media, and between hot and cold secondary medium streams, reducing the need for complex external control mechanisms while maintaining high temperature control precision.
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 solution prevents temperature peaks and ensures a consistent, safe temperature at the tap, reducing the risk of scalding and improving user experience by maintaining the desired temperature with efficient heat transfer and minimal reheating.
Implementation Method 1
a control heat exchanger (1) for the primary medium... a main heat exchanger (21)... The primary medium and the secondary medium are connected in countercurrent to one another in both the control heat exchanger and in the main heat exchanger
Implementation Method 2
The primary medium and the secondary medium are connected in countercurrent to one another in both the control heat exchanger and in the main heat exchanger
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Control system for providing a secondary medium heated by a primary medium at a tapping point in a building, with a main heat exchanger and a throttle, with a control heat exchanger being provided in addition to the main heat exchanger, which is arranged in series with the main heat exchanger, and that the throttle is set up to Dependency of a temperature gauge on the secondary medium to act on an actuator for the primary medium.