Thermal Control Device with Pressure Regulating Valve
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Solution Overview
Problem
Existing thermal control devices for spacecraft, such as two-phase heat transfer loops, face challenges in maintaining a stable temperature of onboard electronics due to constant conductance, leading to potential overheating or overcooling, particularly at low operational temperatures, and require additional power sources or complex valve systems prone to leakage.
Innovation Solution
A thermal control device utilizing a two-way regulating valve to adjust hydraulic resistance in the fluid circuit, either in the vapor or liquid transport line, eliminating the need for a bypass line and ensuring constant evaporator temperature independent of the condenser temperature, with an optional heater for active control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a two-phase heat transfer loop is used to transfer heat from electronics to external radiators, then heat transfer efficiency is improved, but the electronics may be overcooled below acceptable temperature limits when radiator temperature reaches very low values
Solution Approach 1:
The patent applies a three-way pressure regulating valve to dynamically control the vapor flow distribution between the condenser and bypass line. This dynamic adjustment allows the system to adapt to varying thermal conditions, preventing overcooling of electronics when radiator temperature drops by redirecting vapor flow through the bypass line, thereby resolving the contradiction between heat transfer efficiency and temperature control stability
Solution Approach 2:
The patent changes the pressure parameter in the vapor line using a pressure regulating valve to control temperature. By adjusting the pressure, the system can maintain stable electronics temperature independent of radiator temperature variations, resolving the contradiction between efficient heat transfer and temperature stability
2Use of energy by stationary object
If a three-way pressure regulating valve is installed in the vapor line to control temperature, then temperature control is achieved without additional power sources, but vapor flow leakage into the bypass line degrades heat transfer performance and may cause overheating
Solution Approach 1:
The patent employs a pressure regulating valve that automatically adjusts vapor flow distribution based on pressure feedback from the system. This feedback mechanism ensures that vapor flow is properly directed between the condenser and bypass line, preventing leakage that would degrade heat transfer performance while maintaining passive operation without additional power sources
Solution Approach 2:
The patent uses a relatively simple pressure regulating valve instead of complex active control systems with multiple power sources. This simpler component achieves the desired temperature control and vapor flow management functions cost-effectively, accepting potential performance degradation as a trade-off for eliminating complex power requirements
3Adaptability or versatility
If a three-way pressure regulating valve is used for temperature control, then passive control without power source is achieved, but it is difficult to guarantee leakage absence since metallic powder particles can migrate and deposit on the valve stem and seat
Solution Approach 1:
The patent anticipates the potential leakage problem from metallic powder particle deposition by designing a pressure regulating valve system that can tolerate some degree of particle presence. The pressure-based control mechanism provides a margin of safety that cushions against performance degradation from particle accumulation, maintaining reliable operation despite the inherent contamination risk
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 maintains a constant temperature of the heat source by varying hydraulic resistance, preventing overheating or overcooling, and reducing power consumption by eliminating the need for additional power sources and complex valve systems, while ensuring reliable temperature control.
Implementation Method 1
During nominal operation of the two phase heat transfer loop, two phases of this working fluid, vapour and liquid, are always present in the circuit
Implementation Method 2
an evaporator, a vapour transport line, a condenser and a liquid transport line
Implementation Method 3
an evaporator, a vapour transport line, a condenser and a liquid transport line
Implementation Method 4
capillary pumps (which are the most commonly used, since they do not need any source of energy to work)
Implementation Method 5
this rejection is made by thermal radiation through dedicated radiators installed on the satellite external surfaces
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Thermal control device for controlling the temperature of a heat source (7) by means of transferring heat from the heat source (7) to a heat sink (8) by means of the circulation of a fluid in the device, said device comprising an evaporator (2) collecting heat from the heat source (7), a condenser (4) rejecting heat to the heat sink (8), and transport lines (3, 5) connecting the evaporator (2) and the condenser (4), the fluid flowing through said transport lines (3, 5), the device further comprising a valve (20) located in one of the transport lines (3, 5), said valve (20) opening and closing the flow of fluid in the transport line (3, 5) modifying the hydraulic resistance of said transport line (3, 5), the pressure drop in the circuit of transport lines (3,5) - valve (20) - condenser (4) being such that enables to maintain the evaporator operation temperature (Top) substantially within a predetermined value, independent on the condenser temperature (Tc).