Device for measuring temperatures in a heat exchanger
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Brazed plate heat exchangers face challenges in local temperature measurement due to their compact and monolithic construction, making it difficult to access and measure temperature variations within the exchanger, which limits control and monitoring capabilities and can lead to issues like fluid distribution problems and phase changes.
Innovation Solution
A brazed plate heat exchanger design that incorporates a temperature probe integrated into a slot within the corrugated exchange structure, allowing direct and precise local temperature measurements with minimal disruption to fluid flow, using resistive, thermocouple, or thermistor probes, and ensuring a fluidtight seal to maintain measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If brazed plate heat exchangers are designed with compact monolithic construction, then heat exchange efficiency and space utilization are improved, but local temperature measurement capability deteriorates
Solution Approach 1:
The heat exchanger is segmented by incorporating discrete temperature probe assemblies at specific locations within the plate pack. Each probe assembly includes a temperature probe, retaining component, and thermal conductor that can be independently installed and positioned, allowing local temperature measurements without compromising the overall compact monolithic structure.
Solution Approach 2:
A thermal conductor element acts as an intermediary between the temperature probe and the fluid passage. This thermal conductor is in thermal contact with both the probe and the fluid, enabling accurate temperature measurement of the fluid without requiring direct insertion of the probe into the flow path, thus maintaining compactness while enabling measurement.
2Measurement precision
If temperature probes are inserted into fluid passages for direct measurement, then temperature measurement accuracy is improved, but fluid flow disruption increases
Solution Approach 1:
The thermal conductor serves as an intermediary that transfers thermal energy from the fluid to the temperature probe without requiring the probe to be in direct contact with the fluid flow. This eliminates flow disruption while maintaining measurement accuracy through thermal coupling.
Solution Approach 2:
The mechanical insertion of the probe into the fluid passage is replaced by a thermal coupling system where the thermal conductor establishes thermal contact with the fluid passage wall or fluid. This substitution eliminates mechanical interference with fluid flow while maintaining thermal measurement capability.
3Reliability
If retaining components are added to hold temperature probes, then measurement stability is improved, but device complexity increases
Solution Approach 1:
The retaining component is merged with existing structural elements of the heat exchanger, such as the plate edges or support structures. This integration allows the temperature probe to be securely retained without adding separate complex retaining mechanisms, maintaining measurement stability while minimizing additional complexity.
Solution Approach 2:
The retaining component is designed to serve multiple functions: securing the temperature probe in position, providing thermal contact between the probe and fluid passage, and potentially serving as a mounting point for other instrumentation. This multi-functionality reduces overall device complexity while maintaining measurement stability.
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 precise and direct local temperature measurements within the heat exchanger, facilitating in-situ detection of operating issues and performance monitoring, while minimizing space requirements and fluid flow disruption.
Implementation Method 1
a temperature probe (14) arranged in the slot (12)
Implementation Method 2
a heat exchanger that vaporizes a flow of liquid, for example liquid oxygen, nitrogen and/or argon, by exchanging heat with a gaseous flow, for example air or nitrogen
Implementation Method 3
exchanging heat with a gaseous flow
Implementation Method 4
the plates, the fin spacer elements and the other constituent elements of the exchanger are pressed against one another and are subsequently joined together by brazing in a vacuum furnace at temperatures that may be between 550 and 900° C.
Data Source
AI summary
The invention relates to a heat exchanger of the brazed plate and fin type including a stack of plates arranged parallel to one another and to a longitudinal direction so as to define, between the plates, a plurality of passages suitable for the flow of at least a first fluid in the longitudinal direction, at least one exchange structure of corrugated shape being arranged between two successive plates and having corrugation crests and corrugation troughs connected alternately by a succession of fins. The fins succeeding one another in a lateral direction which is orthogonal to the longitudinal direction and which defines a direction of corrugation of the exchange structure, and the corrugation crests and troughs being arranged against the plates and having a thickness measured parallel to a direction of stacking which is perpendicular to the longitudinal direction and to the lateral direction.