High Thermal Storage Density Of High-Quality Conventional Sensible Heat Storage Materials - Resist Extreme Temperature Changes With Excellent Latent Heat Of Phase Change: Military Aviation PCM

High Thermal Storage Density Of High-Quality Conventional Sensible Heat Storage Materials - Resist Extreme Temperature Changes With Excellent Latent Heat Of Phase Change: Military Aviation PCM

Introduction to Phase change materials for military aviation:

-- Basic information

• Military aviation phase change material is a kind of special material specially used in the field of military aviation, according to the change of environmental temperature, when the phase change temperature is reached, the phase change material begins to phase change, absorb or release a lot of heat, and the phase change temperature is basically unchanged to maintain the relatively constant environmental temperature.

-- Material type
1. Solid-liquid phase change material

• This is the most common type of phase change material used in military aviation.
• When the temperature is raised to the phase transition temperature, the material changes from a solid to a liquid state, absorbing a large amount of heat.
• When the temperature drops, it goes back from the liquid to the solid, releasing heat.
• For example, some organic phase change materials such as paraffin, fatty acids, etc., and some alloy materials belong to solid-liquid phase variable materials.

2. Solid-gas phase change materials

• Such materials go directly from solid to gas during the phase transition process, which absorbs a lot of heat.
• However, due to the large variation in the volume of the gas, it has relatively few applications in the aviation field, and usually requires special packaging and control technology.

3. Liquid-gas phase change materials

• The transformation of a liquid into a gas also absorbs a lot of heat.
• However, the application in the aviation field is also limited, mainly because the volume and pressure changes of the gas are difficult to control, and the sealing requirements of the container are extremely high.

Material characteristics:
1. Good thermal conductivity

• Although the thermal conductivity of the phase change material itself may be relatively low, its thermal conductivity can be improved by adding high thermal conductivity fillers or using special structural design.
• Good thermal conductivity can ensure that the phase change material responds quickly when absorbing or releasing heat, improving the efficiency of heat transfer, so as to better achieve temperature control of aviation equipment.

2. Suitable phase change temperature

• Phase change temperature is one of the key parameters of phase change materials, for military aviation applications, it is necessary to select a material whose phase change temperature matches the operating temperature range of aviation equipment.
• In this way, it can be ensured that the phase change material can undergo phase change at the right temperature during the operation of the equipment, and effectively store and release energy.

3. Small volume changes

• During the phase transition process, the volume change of the material should be as small as possible to avoid affecting the structure and packaging of the aviation equipment.
• If the volume change is too large, it may lead to problems such as packaging rupture and leakage of materials, affecting the normal operation and safety of the equipment.

4. Good repeatability

• Phase change materials need to have good repeatability, that is, to maintain stable properties after multiple phase change cycles.
• This is important for the long-term use of military aviation equipment to ensure that phase change materials continue to perform effective thermal management throughout their service life.

Application cases of materials:
 

-- Individual thermal protective equipment for pilots
1. Flight suit temperature control

• When flying at high altitudes, pilots face extreme temperature environments, such as extremely low outside temperatures at high altitudes, and heat emitted by electronic devices in the cockpit may cause local temperatures to rise.
• The application of phase change materials in the lining or sandwich of the flight suit can automatically absorb or release heat according to temperature changes, maintain the comfortable temperature of the pilot's body, and reduce the impact of temperature discomfort on the pilot's operation and health.
• For example, in cold environments, phase change materials from liquid to solid release heat and provide warmth to the pilot; When the temperature in the cockpit rises, the phase-change material absorbs heat and prevents the pilot from overheating.

2. Helmet thermal management

• The pilot's helmet integrates many electronic devices, such as communication devices, night vision devices, etc., which generate heat when they work, and can lead to stuffy and uncomfortable heads when worn for a long time.
• Adding phase change materials to the inside of the helmet can effectively absorb the heat generated by electronic devices, keep the head cool, and improve the pilot's wearing comfort and concentration.

-- Aircraft fuel system temperature regulation
1. Prevent fuel from overheating

• During flight, fuel heats up due to contact with components such as the engine and air friction.
• Excessive fuel temperature may affect the performance and safety of the fuel, and even cause hazards such as fire. The phase change material is wrapped around the fuel line or fuel tank, and when the fuel temperature rises to the phase change temperature of the phase change material, the phase change material absorbs heat, reduces the temperature of the fuel, and prevents the fuel from overheating.
• For example, when the fighter is carrying out high-intensity flight training or performing tasks, the temperature regulation function of this fuel system is particularly important to ensure the normal supply of fuel and the safe flight of the aircraft.

2. Improve fuel low temperature performance

• When flying at high altitudes or in cold areas, the fluidity of fuel will be reduced, affecting the supply of fuel and the normal operation of the engine.
• Using the characteristics of phase change materials to release heat at low temperatures can provide additional heat to the fuel system, maintain the fluidity of fuel, and ensure the normal operation of the aircraft in a low temperature environment.