Thermal Safeguard Closure Bushing Segmentation
Solution Overview
Problem
Existing closures with thermal safeguard functions in hydrodynamic turbomachines have non-reproducible triggering behavior and slow response times due to the large heat capacity of the closure body influencing the fusible safeguard element.
Innovation Solution
The closure design includes a bushing with reduced heat capacity by providing insulation between the closure body and the fusible safeguard element, and a cylindrical axial prolongation with a thin wall thickness to minimize the influence of the closure body's heat capacity, allowing for a faster and more precise response. The fusible safeguard element is inserted into the bushing or directly into the closure body, and a eutectic fusible solder is used with a reduced axial length and cross-sectional expansion for efficient temperature transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the closure body has a large heat capacity to ensure structural integrity and pressure resistance, then the closure is reliable under high pressure, but the response time of the thermal safeguard function increases and triggering behavior becomes non-reproducible
Solution Approach 1:
The closure body is segmented into two functional zones: a thick-walled region for structural integrity and pressure resistance, and a thin-walled axial prolongation region for rapid thermal response. This segmentation allows each zone to fulfill its specific function without compromising the other.
Solution Approach 2:
Different wall thicknesses are applied to different regions of the closure body. The axial prolongation has a reduced wall thickness (1-2.5mm) compared to the main body, creating local thermal sensitivity in the region where temperature measurement and safeguard triggering occur, while the rest of the body maintains structural strength.
2Strength
If the fusible safeguard element is surrounded by a large mass of closure body material, then the closure provides mechanical strength, but the heat capacity influence delays and randomizes the triggering temperature
Solution Approach 1:
The closure body is divided into a thick-walled main structure and a thin-walled axial prolongation. The fusible safeguard element is positioned within the axial prolongation, ensuring it is surrounded by minimal material mass (1-2.5mm wall thickness) for precise thermal response, while the main body provides overall mechanical strength.
Solution Approach 2:
The axial prolongation region has locally reduced wall thickness specifically where the fusible safeguard element is located. This creates a localized zone of low thermal mass that enables precise and reproducible triggering at the designated temperature threshold, while the rest of the closure body maintains full structural integrity.
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 design achieves a rapid and highly reproducible triggering behavior, preventing excessive overheating in hydrodynamic turbomachines by ensuring a fast and precise response to elevated temperatures.
Implementation Method 1
The thermal safeguard function in the sense of the present invention means that the closure, which takes on a temperature that depends on the temperature in the interior of the cavity, is fluid-tight below a pre-given temperature threshold and opens automatically above a pre-given threshold
Implementation Method 2
The closure design includes a bushing with reduced heat capacity by providing insulation between the closure body and the fusible safeguard element, and a cylindrical axial prolongation with a thin wall thickness to minimize the influence of the closure body's heat capacity
Data Source
AI summary
The invention relates to a closure with a thermal safeguard function, comprising a closure body (1), which is used to seal a cavity (10) that is to be closed; a fusible safeguard element (2), which is inserted into the closure body and which keeps closed, at least indirectly, a through-opening (1.1), which is formed in the closure body. The inventive closure with a thermal safeguard function is characterized by the following features: the closure body comprises a bushing (3) provided with a continuous bore (3.1); the bushing is inserted into the through-opening of the closure body at an axial end (1.3) in such a way that the continuous bore and the region of the through-opening that is axially adjacent to the bushing are aligned flush with each other; the fusible safeguard element completely fills the continuous bore of the bushing over the entire cross section thereof along a given axial length.