Thermal control loop
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Solution Overview
Problem
In microgravity and zero gravity environments, two-phase chiller systems face challenges in separating and collecting liquid refrigerant from a mixture of liquid and vapor, leading to potential damage or inefficiency due to vapor delivery to pumps causing cavitation, and existing capillary materials are difficult to design and manufacture for efficient liquid collection.
Innovation Solution
A thermal control loop incorporating a porous capillary media wrapped around rigid structures within a reservoir, with features like corner grooves and pockets that facilitate liquid flow to a collection tube, and a vapor-liquid separator using centrifugal momentum to separate liquids from vapors, ensuring efficient liquid collection without external power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If capillary material is used to separate liquid from vapor in microgravity, then liquid collection is improved, but the system becomes difficult to design and manufacture efficiently
Solution Approach 1:
The patent employs porous wicking material with specific pore structures to enable capillary action for liquid collection. The porous material is configured with varying pore sizes and distributions to optimize liquid wicking while maintaining manufacturability through standard fabrication processes.
Solution Approach 2:
The wicking material is positioned and configured with varying properties at different locations within the accumulator. The material density, pore size, and arrangement are locally optimized to guide liquid flow from the vapor-liquid interface toward the liquid outlet, addressing specific flow challenges in different regions.
2Reliability
If vapor is delivered to the pump in a two-phase chiller system, then the pump may experience cavitation damage or operate less efficiently
Solution Approach 1:
The invention extracts and removes vapor from the liquid phase before delivery to the pump. The accumulator design separates vapor and liquid phases, with the liquid outlet positioned to draw only liquid refrigerant, excluding vapor from the pump inlet and preventing cavitation.
Solution Approach 2:
The accumulator is segmented into distinct vapor and liquid regions. The liquid collection system is separated from the vapor space, with wicking material confined to liquid collection zones, ensuring that only liquid reaches the pump while vapor remains in its designated compartment.
3Stability of the object's composition
If fluid distributes throughout the reservoir in microgravity, then liquid and vapor separate by attachment to walls and floating in cavity, but this distribution raises challenges for drawing liquid phase from reservoir
Solution Approach 1:
The wicking material acts as an intermediary between the liquid-vapor interface and the liquid outlet. It capillary-wicks liquid through the porous structure, providing a reliable transport path that overcomes microgravity distribution challenges and ensures consistent liquid delivery to the pump.
Solution Approach 2:
The invention replaces mechanical pumping or gravitational drainage with capillary action in porous material. This passive transport mechanism eliminates the need for mechanical intervention to overcome microgravity fluid distribution, enabling reliable liquid collection without additional energy input.
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 solution effectively separates and collects liquid refrigerant, preventing pump cavitation and maintaining system efficiency across varying conditions, even in microgravity, by utilizing the porous capillary media and vapor-liquid separator to ensure a predominantly liquid flow to the pump, enhancing the thermal control loop's operational reliability.
Implementation Method 1
A thermal control loop incorporates an accumulator having a reservoir that defines a vapor-liquid separation volume. The thermal control loop also incorporates porous capillary media wrapped around rigid structures within the reservoir
Implementation Method 2
a vapor-liquid separator using centrifugal momentum to separate liquids from vapors
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A thermal control loop, comprising a pump (14) for pumping a liquid refrigerant; an evaporator (22) for removing heat from a heat source and transferring heat to the liquid refrigerant; a condenser (30) for removing heat from the liquid refrigerant; and an accumulator (42) comprising: A reservoir (54) including a reservoir exit line (121); at least one rigid structure (56) disposed within the reservoir and configured to collect a liquid and direct the liquid to the reservoir exit line; a first porous capillary media (64) supported by the at least one rigid structure; and a vapor-liquid separator (110) in contact with at least one of the at least one rigid structure and the first porous capillary media including a guide member (114) extending along a guide member axis having a guide inlet (119) and a guide outlet (128) connected by a spiral conduit; and a second porous capillary media (122) located radially outward from the spiral conduit on an exterior surface of the guide member.