Two-Loop Evaporator Layout for Vapor Bubble Removal in Low Gravity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current two-phase heat transfer systems face challenges in efficiently managing fluid circulation and vapor bubble removal in zero or low-gravity environments, particularly in satellite and electronic cooling applications, where capillary pressure is insufficient to ensure adequate wetting and heat transfer.
Innovation Solution
A heat transfer system comprising a first loop with primary evaporators connected in series and parallel to a condenser, and a second loop with a reservoir and secondary evaporator, utilizing coupling lines and a sweepage line to ensure fluid communication and vapor bubble removal, along with a porous structure to enhance capillary pressure and thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-loop heat transfer system is used, then system simplicity is maintained, but vapor bubble removal is insufficient
Solution Approach 1:
The heat transfer system is segmented into two distinct loops: a primary loop for main heat transfer operations and a secondary loop specifically designed for vapor bubble removal and fluid redistribution. This segmentation allows each loop to be optimized for its specific function.
Solution Approach 2:
The vapor bubble removal function is extracted from the primary heat transfer loop and assigned to the secondary loop. The sweepage line in the secondary loop actively sweeps vapor bubbles away from the evaporator, preventing their accumulation and maintaining system reliability.
2Ease of manufacture
If conventional evaporator configuration is used, then manufacturing simplicity is maintained, but heat transfer efficiency in low-gravity is insufficient
Solution Approach 1:
The evaporator is designed with a porous structure at its base that provides enhanced capillary action locally where fluid distribution is most critical. This localized enhancement improves heat transfer efficiency without requiring complete redesign of the entire evaporator structure.
Solution Approach 2:
The evaporator incorporates a porous structure made of materials with optimized capillary properties, combining them with the evaporator body material. This composite approach enhances fluid distribution and heat transfer efficiency while maintaining manufacturing feasibility.
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 system effectively redistributes sub-cooled liquid, balances heat conduction, and ensures adequate wetting of wicks, improving heat transfer efficiency and reliability in various gravitational conditions.
Implementation Method 1
These systems utilize capillary pressure developed in a fine-pored wick within the evaporator to promote circulation of working fluid from the evaporator to the condenser and back to the evaporator.
Implementation Method 2
The evaporator includes a wick that enables liquid flow.
Implementation Method 3
utilizing coupling lines and a sweepage line to ensure fluid communication and vapor bubble removal, along with a porous structure to enhance capillary pressure and thermal conductivity.
Implementation Method 4
Loop Heat Pipes (LHPs) and Capillary Pumped Loops (CPLs) are examples of passive two-phase loop heat transfer systems.
Implementation Method 5
The evaporator thermally coupled to the heat source... Heat acquired by the evaporator is transported to and rejected by the condenser.
Implementation Method 6
a condenser thermally coupled to the heat sink... Heat acquired by the evaporator is transported to and rejected by the condenser.
Implementation Method 7
The coupling line and the liquid line can be thermally linked.
Data Source
AI summary
A heat transfer system includes a first loop and a second loop. The first loop includes a condenser having a vapor inlet and a liquid outlet, a vapor line in fluid communication with the vapor inlet of the condenser, a liquid line in fluid communication with the liquid outlet of the condenser, and primary evaporators fluidly coupled in series with the liquid line and in parallel with the vapor line. The second loop includes a reservoir, a secondary evaporator having a vapor outlet coupled to the vapor line and a fluid inlet coupled to the reservoir, and a sweepage line in fluid communication with the reservoir and the primary evaporators.