Hydraulic Damper Thermal Compensation Without Seismic Drift
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Solution Overview
Problem
Existing hydraulic dissipation devices face challenges in achieving high dissipation capacity while prohibiting low-speed movements and maintaining a fixed point under seismic conditions, with current solutions either affecting dynamic behavior or requiring heavy maintenance.
Innovation Solution
A hydraulic dissipation device with a cylinder, piston, and thermal compensation circuit that isolates the compressed chamber and connects the relaxed chamber to a hydraulic accumulator, using pressure differential-controlled valves and non-return valves to manage fluid flow, allowing for both fixed-point behavior and viscous dissipation, and incorporating bypass circuits for automatic refocusing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If nozzles are used to allow thermal expansion and controlled leakage, then thermal compensation is achieved, but low-speed movements are permitted which reduces dissipation capacity
Solution Approach 1:
The hydraulic circuit is segmented into two independent thermal compensation circuits, each serving one chamber. This allows selective isolation of chambers during operation, preventing unwanted leakage while maintaining thermal compensation functionality. Each circuit includes its own valve and accumulator connection, enabling independent control of thermal expansion compensation for each chamber.
Solution Approach 2:
The system dynamically switches between different operational modes using controllable valves. During seismic events, valves close to prevent leakage and maximize dissipation capacity. During normal thermal expansion, valves open to allow controlled compensation. This dynamic control allows the system to adapt its behavior based on operational conditions, resolving the contradiction between allowing thermal expansion and preventing energy loss.
2Force
If prestressed viscous damper is used to prevent low-speed movements, then fixed point behavior is achieved, but dissipation capacity is halved and dynamic behavior is strongly affected
Solution Approach 1:
The invention uses hydraulic pressure control through controllable valves and accumulators to achieve fixed point behavior during normal operation. During seismic events, the hydraulic system maintains chamber pressure to prevent unwanted movements while allowing full dissipation capacity through the pressure limiting valves. This hydraulic approach replaces the mechanical prestress of viscous dampers, achieving fixed point stability without sacrificing energy dissipation capability.
Solution Approach 2:
The system changes the operational parameters of the hydraulic circuit based on seismic activity. During normal conditions, the circuit allows thermal expansion compensation. During seismic events, pressure limiting valves open and thermal compensation valves close, changing the system state to provide fixed point behavior while maintaining full dissipation capacity through the energy dissipation circuit.
3Force
If mechanical fuse device is combined with conventional damping device, then fixed point under normal conditions is guaranteed, but heavy maintenance is required after each triggering
Solution Approach 1:
The hydraulic accumulator system provides automatic reset functionality. After a seismic event triggers the pressure limiting valves, the accumulators absorb the pressure surge and maintain system operation. The thermal compensation valves automatically reopen to restore normal thermal expansion compensation. This self-service capability eliminates the need for manual intervention or heavy maintenance after each triggering event.
Solution Approach 2:
The invention replaces the mechanical fuse device with a hydraulic control system using controllable valves and accumulators. This substitution transforms the irreversible mechanical fuse action into a reversible hydraulic process, where the system can automatically reset after seismic events without requiring physical replacement of components or heavy maintenance intervention.
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
The device achieves optimal heat dissipation and prevents drift, ensuring reliable operation without the need for refocusing after seismic events, while maintaining high dissipation capacity and preventing low-speed movements.
Implementation Method 1
the power dissipated by the pressure drop thus generated is dissipated as heat essentially in the oil, causing it to expand
Implementation Method 2
an oleopneumatic accumulator 12 for absorbing the variation in oil volume caused by the dissipation of the hydraulic energy
Implementation Method 3
these valves 21a and 21b generate a pressure drop according to a predefined Flow/Pressure law constituting the dissipation law of the device
Implementation Method 4
the power dissipated by the pressure drop thus generated is dissipated as heat essentially in the oil
Implementation Method 5
the oil can freely go from the accumulator 12 to the corresponding chamber via the non-return valve 24, but the flow rate from this chamber to the accumulator is limited
Data Source
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AI summary
Hydraulic dissipation device (1) for a building or other civil engineering work, comprising: - A cylinder (16), - a piston (14) movable in the cylinder under the effect of a force applied to the damper, - a first (13a) and a second chamber (13b) inside the cylinder, separated by the piston (14), - an energy dissipation circuit (20) connected to the chambers, - a thermal compensation circuit, comprising a hydraulic accumulator (12) and a hydraulic circuit (30) connecting the accumulator to each of the chambers and arranged to make the chamber with the lowest pressure communicate with the accumulator while the other chamber remains isolated from the accumulator.