Thermal conductivity refers to the ability of a metal to conduct heat. This characteristic is different in different types of metals, and it is important to consider this in common high operating temperature applications.
In pure metals, the thermal conductivity remains roughly constant with the increase of temperature. The thermal conductivity of the alloy increases with the increase of temperature.
As you can see, among the more common metals, copper and aluminum have the highest thermal conductivity, while steel and bronze have the lowest thermal conductivity. Thermal conductivity is a very important characteristic in determining which metal to use for a particular application. As copper is an excellent heat conductor, it is suitable for heat exchangers, radiators and even the bottom of pans. Because steel is a poor conductor of heat, it is very suitable for use in high temperature environments such as aircraft engines.
The following are some important applications that require good metal heat conduction:
Heat exchanger is a common application, in which good thermal conductivity is important. Heat exchangers heat or cool by transferring heat.
Copper is a popular choice for heat exchangers in industrial equipment, air conditioning, refrigeration, hot water tanks and floor heating systems. Its high thermal conductivity allows heat to pass through it quickly. Copper has the additional properties required by heat exchangers, including corrosion resistance, biofouling, stress and thermal expansion.
Aluminum can also be used in some heat exchanger applications as a more cost-effective alternative.
Heat exchangers are commonly used in the following situations:
Heat exchangers in industrial facilities include fossil and nuclear power plants, chemical plants, desalination plants and marine services.
In industrial equipment, copper nickel alloy is used to build heat exchange tubes. The alloy has good corrosion resistance and is not corroded in seawater environment. It also has good biological antifouling ability to avoid the formation of algae and seaweed. Aluminum brass alloys have similar properties and can be used as substitutes.
Solar water heating system
The solar water heater is an economical and effective way to heat water. One of the copper tubes is used to transfer solar heat energy to water. Copper is used because of its high thermal conductivity, resistance to air and water corrosion, and mechanical strength.
Gas water heater
The gas water heat exchanger transfers the heat generated by the gas fuel to the water supply. They are common in residential and commercial boilers. For gas water heaters, copper is the preferred material because of its high thermal conductivity and ease of manufacture.
Forced air heating and cooling
Heat pumps using air have long been used for residential and commercial heating. They perform air to air heat exchange through the evaporator unit. They can be used in wood furnaces, boilers and stoves. In addition, copper is usually used because of its high thermal conductivity.
A radiator is a heat exchanger that transfers heat generated by electronic or mechanical equipment to moving coolant. The liquid transfers heat from the equipment and cools it to the required temperature. Use metals with high thermal conductivity.
The computer uses heat sinks to cool the CPU or graphics processor. Radiators are also used for high-power devices, such as power transistors, lasers and light emitting diodes (LEDs).
The radiator is designed to maximize the surface area in contact with the coolant.
Aluminum alloy is the most common radiator material. This is because aluminum is cheaper than copper. However, copper is used to require a higher level of thermal conductivity. Some radiators use a combination of aluminum fins and a copper base.
Household metals with good thermal conductivity are mostly used for cooking utensils. When you heat food, you don’t want to wait all day. This is why copper is used in the bottom of high-quality cookware, because the metal can conduct heat rapidly and diffuse evenly on its surface.
However, if your budget is limited, you can use aluminum cookers as a substitute. It may take some time to heat the food, but your wallet will thank you!