Two-phase fluid loop with mechanical pumping and a device for passive control of throughflow
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Solution Overview
Problem
Current two-phase fluid loops with mechanical pumping in satellite applications fail to dynamically and passively adjust heat dissipation fluid flow according to varying environmental conditions on non-symmetrical satellite surfaces, leading to suboptimal heat rejection.
Innovation Solution
A passive control device for a two-phase fluid loop with mechanical pumping, featuring a condenser design with a variable hydraulic resistance that adjusts fluid flow based on thermal environment, utilizing a longer flow path and potentially a central three-dimensional part with a helical spiral flow path or porous medium to optimize fluid distribution across multiple radiators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a traditional two-phase fluid loop is used with parallel condensers for multiple radiators, then the system structure is simple, but the flow rate to each wall is similar and cannot be adjusted to environmental variations
Solution Approach 1:
The condenser uses its own condensation process to generate variable hydraulic resistance that passively regulates flow distribution. The system self-adjusts without external control by utilizing the physical phenomenon where condensation rate varies with environmental conditions, creating different pressure drops across parallel condensers to redirect flow toward shaded walls.
Solution Approach 2:
The hydraulic resistance parameter of the condenser is made variable through the condensation process. As environmental conditions change (solar exposure), the condensation rate changes, which dynamically alters the hydraulic resistance and consequently the flow distribution to different radiators without mechanical adjustment.
2Productivity
If the flow rate to each wall is kept similar without control system, then the device complexity is low, but the heat rejection is significantly deoptimized
Solution Approach 1:
The system automatically optimizes heat rejection by using the condensation process itself to regulate flow. When one wall is shaded and needs more cooling, the condenser on that wall experiences different condensation conditions that naturally create lower hydraulic resistance, directing more flow there without external control.
Solution Approach 2:
The patent replaces mechanical flow control systems (valves, actuators, controllers) with a passive hydraulic resistance mechanism based on thermodynamic condensation processes. This eliminates complex mechanical control while achieving optimal heat rejection distribution.
3Productivity
If multiple HPWHs are installed to utilize east/west walls, then the heat rejection capability is improved, but the integration complexity increases significantly
Solution Approach 1:
The patent merges the flow regulation function into the condenser structure itself rather than adding separate control devices. The condenser serves dual purposes: heat rejection and passive flow control for the entire system, eliminating the need for multiple independent HPWH control systems.
Solution Approach 2:
The condenser is designed to perform multiple functions: it rejects heat to the environment, regulates flow distribution to different radiators, and adapts to varying environmental conditions. This multi-functionality eliminates the need for separate dedicated control mechanisms for each radiator.
4Adaptability or versatility
If a porous component is used at the junction to block steam, then the flow distribution is controlled, but true regulation is not provided and steam flow is simply blocked
Solution Approach 1:
The patent replaces the porous blocking component with a passive hydraulic resistance mechanism based on two-phase flow dynamics. Instead of mechanically blocking steam, the system uses condensation-induced pressure differences to naturally regulate flow distribution, providing true adaptive control rather than simple blocking.
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 solution allows for adaptive and efficient heat rejection by dynamically adjusting fluid flow rates across satellite surfaces, maximizing heat exchange coefficients and optimizing power rejection without active control, even in asymmetrical thermal environments.
Implementation Method 1
an evaporator, through which the fluid circulates in liquid form at the evaporator inlet, the evaporator being configured to transform the fluid from liquid to partially gaseous form
Implementation Method 2
a condenser, through which the fluid in partially gaseous form circulates at the condenser inlet, the condenser being configured to transform the gaseous phase of the fluid into liquid form
Implementation Method 3
a pump, disposed between the condenser outlet and the evaporator inlet, intended to move the fluid in the closed circuit from the evaporator to the condenser in partially gaseous form and from the condenser to the evaporator in liquid form
Implementation Method 4
The two-phase fluid loop thermo-hydraulically affects several satellite radiators at the condenser level to reject power dissipated by the satellite's equipment
Data Source
Figure 1~2
AI summary
The invention relates to a passive control device (10) for distributing the flow of a fluid in a mechanically pumped two-phase fluid loop, the loop comprising: - a closed circuit (11) in which a heat transfer fluid circulates; - an evaporator (12) through which the fluid flows from an inlet (13) of the evaporator (12) in liquid form (20-liq) to an outlet (14) of the evaporator (12), the evaporator (12) being configured to transform the fluid in liquid form (20-liq) into fluid in a partially gaseous form (20-g); - at least two condensers (15) mounted in parallel, each comprising an inlet (16) and an outlet (17) connected to the inlet (16) by a passage channel (35), through which the fluid in a partially gaseous form (20-g) flows to be transformed into fluid in liquid form (20-liq);- a fluid circulation device (18), disposed between the outlet (17) of the condenser (15) and the inlet (13) of the evaporator (12), intended to move the fluid in the closed circuit (11); where the passage channel (35) of the condenser (15) extends over a first length (31) and in that it includes a flow path (32) of the fluid in partially gaseous form (20-g) of a length greater than the first length (31).;