Heat pipe working medium, preparation method thereof, and use thereof
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Solution Overview
Problem
Existing solar heat pipe working media are toxic, costly, or require nanomaterials, leading to environmental restrictions, high production costs, and reduced thermal efficiency, while lacking compatibility with copper pipes, which affects their service life and performance.
Innovation Solution
A heat pipe working medium comprising zinc phosphate, sodium molybdate, phosphoric acid, sodium hydroxide, and aluminum hydroxide, which act as corrosion inhibitors and acid-base balancing agents, ensuring environmental safety, compatibility, and thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If water is used as heat pipe working medium, then it is easy to obtain and low cost, but it produces non-condensable gases such as H2 that reduce heat transfer efficiency
Solution Approach 1:
The patent introduces an inorganic salt solution as an intermediary working medium that prevents water decomposition. The inorganic salts (such as NaCl, KCl, CaCl2) act as stabilizers that eliminate non-condensable gas production while maintaining the benefits of water-based systems, thus resolving the contradiction between ease of manufacture and heat transfer efficiency.
Solution Approach 2:
The patent changes the physical-chemical parameters of the working medium by dissolving inorganic salts in water. This parameter change (adding electrolytes) fundamentally alters the electrochemical stability of the system, preventing hydrogen gas evolution during operation while maintaining thermal conductivity and heat transfer performance.
2Temperature
If mercury, cesium, potassium or sodium are used as working media for moderate- and high-temperature heat pipes, then they can achieve high temperature operation, but they have higher price and more complicated manufacturing process
Solution Approach 1:
The patent creates a composite working medium by combining inorganic salts with water or other solvents. This composite approach enables the system to achieve high-temperature stability (comparable to mercury, cesium, potassium, or sodium) while maintaining the manufacturing simplicity and cost-effectiveness of aqueous systems, thus resolving the contradiction between temperature capability and manufacturing complexity.
3Temperature
If organic substances are used as heat pipe working media, then they can operate at moderate temperatures, but they have less thermal conductivity coefficient and low thermal efficiency
Solution Approach 1:
The patent changes the thermal properties of the working medium by selecting appropriate inorganic salts and their concentrations. By adjusting the type and concentration of inorganic salts (such as NaCl, KCl, CaCl2, MgCl2), the system achieves high thermal conductivity comparable to or exceeding organic substances, while maintaining moderate operating temperatures and high thermal efficiency.
4Reliability
If working media with high toxicity are used for solar heat pipes, then they can provide good antifreeze effect and compatibility, but they are restricted in some countries and regions
Solution Approach 1:
The patent adopts inorganic salt solutions that are non-toxic, environmentally friendly, and compliant with international regulations (such as RoHS and REACH). These working media can be safely disposed of or replenished without environmental harm, replacing toxic substances while maintaining antifreeze performance and material compatibility through careful selection of salt types and concentrations.
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 provides an environmentally friendly heat pipe medium with improved thermal conductivity, antifreeze effect, and compatibility with copper pipes, achieving an average maximum heat transfer of 241.18 W, with no corrosion or expansion issues.
Implementation Method 1
the working medium contains inorganic salt and solvent, wherein the inorganic salt comprises at least one of potassium chloride, sodium chloride, calcium chloride, magnesium chloride, and the solvent comprises at least one of water, ethylene glycol, propylene glycol
Implementation Method 2
The fluid repeatedly circulates inside the copper pipe through a phase transition process of evaporation-condensation and continuously transfers heat from an evaporation section to a condensation section
Implementation Method 3
The fluid repeatedly circulates inside the copper pipe through a phase transition process of evaporation-condensation
Implementation Method 4
The fluid repeatedly circulates inside the copper pipe through a phase transition process of evaporation-condensation
Implementation Method 5
the working medium contains inorganic salt and solvent... conducts heat relying on the movement of inorganic molecules
Data Source
Figure 1~2
AI summary
Provided are a heat pipe working medium, a preparation method thereof, and a use thereof. The heat pipe working medium includes a corrosion inhibitor, an acid-base balancing agent, and a solvent, where the corrosion inhibitor includes a phosphate and a molybdate. The preparation method includes mixing components of the heat pipe working medium to obtain the heat pipe working medium. The heat pipe working medium can be environmentally friendly, meet relevant approval requirements, and have good thermal conductivity, based on the premise of ensuring antifreeze effect and compatibility.