Assembly for electronic control of heating water by means of a plate heat exchanger
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Solution Overview
Problem
Existing electronic control systems for water heating via plate heat exchangers face challenges in maintaining a constant temperature on the secondary side due to load fluctuations, often requiring excessive and costly components, leading to inefficient and imprecise temperature regulation.
Innovation Solution
The implementation of a second temperature sensor positioned in the cold water return area of the plate heat exchanger, connected to a controller, allows for precise control of the primary volumetric flow, ensuring a constant temperature of 60°C on the secondary side by detecting temperature changes and adjusting the flow accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a first temperature sensor is arranged in the secondary area connection area and PID algorithm is used for primary volume flow control, then the temperature control system is simple to implement, but temperature overshooting and undershooting occur when load changes or primary side conditions change
Solution Approach 1:
The second temperature sensor is positioned upstream in the cold water return area before the heat exchanger, enabling the control system to detect temperature changes before they reach the outlet. This preliminary detection allows the PID controller to anticipate and compensate for temperature variations, preventing overshooting and undershooting by adjusting the primary volume flow in advance.
2Manufacturing precision
If an additional flow detection sensor is installed on the secondary side and multiple sensors are used for control, then temperature fluctuations are counteracted, but the number of components increases leading to higher costs and implementation effort
Solution Approach 1:
The patent extracts the essential function of temperature measurement from the complex array of sensors and flow detectors. By using only two temperature sensors (one in the secondary area outlet and one in the cold water return area) and eliminating the need for flow detection sensors, the system achieves precise temperature control with minimal components, reducing both cost and implementation complexity.
3Manufacturing precision
If temperature sensors are arranged on primary and secondary flow and return with differential pressure gauge for volume flow measurement, then hot water temperature control is achieved, but excessive components are used increasing implementation effort and cost without reliability advantage
Solution Approach 1:
The patent replaces expensive and complex differential pressure gauges with simple temperature sensors. The second temperature sensor in the cold water return area provides the necessary information for volume flow control through temperature differential measurement, eliminating the need for costly pressure measurement devices while maintaining control precision.
4Speed
If multiple temperature sensors are positioned at different locations for rapid control, then response to sudden demand is improved, but the structure becomes complicated and implementation effort increases
Solution Approach 1:
The second temperature sensor is strategically positioned in the cold water return area upstream of the heat exchanger, where it can detect temperature changes before they propagate through the system. This upstream positioning enables rapid detection and response to load changes without requiring multiple sensors at various locations, achieving fast response with minimal structural complexity.
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 enables immediate and precise control of the secondary side temperature, maintaining it at 60°C despite load changes, with reduced implementation effort and cost, using a DDC controller and strategically placed sensors for optimal performance.
Implementation Method 1
The plate heat exchanger 1 is used to heat or cool a medium on the secondary side from a temperature x to a temperature y, as required
Implementation Method 2
a first temperature sensor 4 is arranged at the flow connection on the secondary side, which is also connected to the controller 2
Implementation Method 3
a second temperature sensor 6 is provided between this mixing point 5 and the cold water connection on the plate heat exchanger 1
Implementation Method 4
In the flow of the plate heat exchanger 1 there is a volume flow control element 3 in connection with the controller 2
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The arrangement has a flow control element (3), which is switched in the supply on a primary side of a plate heat exchanger (1), where a temperature sensor (4) is arranged in flow at the connection on a secondary side of the plate heat exchanger. The flow control element and the temperature sensor are connected to a controller (2). Another temperature sensor (6) is arranged between the area of a mixing point (5) of cold water and secondary connection of hot water, until the end of an inlet chamber of the plate heat exchanger is available for the cold water connection.