Hermetic Split Valve Structure for Stable sCO2 Flow Regulation
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Solution Overview
Problem
Existing split valves in thermal management systems using supercritical carbon dioxide (sCO2) are prone to contamination and pressure loss due to inadequate sealing, leading to inefficiencies and potential phase shifts of sCO2, which compromises the thermal efficiency of the system.
Innovation Solution
Incorporation of hermetic seals, such as metallic bellows, to prevent contamination between sCO2 and hydraulic fluids, and the use of inert gas-filled chambers to mitigate pressure differentials, ensuring the sCO2 remains in a supercritical state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sealing mechanisms are used in split valves, then the device complexity is reduced, but contamination and pressure loss occur leading to sCO2 phase shifts
Solution Approach 1:
A piston is introduced as an intermediary component between the valve body and the sealing mechanism. The piston transmits actuating force while allowing the bellows to perform the sealing function, effectively separating the actuation and sealing functions to improve reliability without excessive complexity
Solution Approach 2:
Metallic bellows are used as the sealing mechanism instead of conventional rigid seals. The bellows provide hermetic sealing through their flexible, expandable structure that can accommodate pressure differentials while maintaining contamination barriers, significantly improving sealing effectiveness
2Reliability
If hermetic seals like metallic bellows are used to prevent contamination, then reliability improves, but device complexity increases
Solution Approach 1:
Metallic bellows serve as hermetic seals that expand and contract to maintain sealing contact while preventing contamination. The bellows structure provides a flexible yet reliable barrier that accommodates pressure variations without compromising the contamination prevention function
Solution Approach 2:
The sealing function is extracted and isolated into a dedicated bellows component, separate from the actuation mechanism. This allows the bellows to be optimized specifically for sealing performance while the piston handles actuation, improving reliability without proportionally increasing overall complexity
3Stability of the object's composition
If inert gas-filled chambers are used to mitigate pressure differentials, then sCO2 remains in supercritical state, but device complexity increases
Solution Approach 1:
An inert gas-filled chamber is introduced as an intermediary pressure buffer between the sCO2 environment and the external atmosphere. The chamber mitigates pressure differentials that could cause phase changes, maintaining sCO2 stability without requiring direct complex control mechanisms
Solution Approach 2:
An inert gas atmosphere is used within the chamber to prevent unwanted chemical reactions and to provide a stable pressure environment. The inert gas acts as a protective medium that maintains the supercritical state of sCO2 by preventing pressure fluctuations that could induce phase transitions
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
Maintains the thermal efficiency of the thermal management system by preventing contamination and pressure loss, ensuring the sCO2 remains in a supercritical state, thereby enhancing the system's operational effectiveness.
Implementation Method 1
Incorporation of hermetic seals, such as metallic bellows, to prevent contamination between sCO2 and hydraulic fluids
Implementation Method 2
the use of inert gas-filled chambers to mitigate pressure differentials, ensuring the sCO2 remains in a supercritical state
Data Source
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AI summary
Example split valves for regulating a first flowrate and a second flowrate of a fluid within a closed loop systems are disclosed herein. An example split valve includes an electrohydraulic servo valve coupled to a first piston via a first hydraulic flowline and a second hydraulic flowline, the first piston to include a piston shaft, a first head, and a second head; one or more bellows fixed to at least one of the first head or the second head, the one or more bellows to hermetically seal the fluid from a hydraulic fluid; and a control system connected to the electrohydraulic servo valve, the control system to adjust the first flowrate and the second flowrate of the fluid through a first fluid chamber, the first piston to be located in the first fluid chamber.