The principle of radiative heat conduction
Heat is not a substance, but a movement of matter. Heat transfer is the transfer of motion, which can be transformed from one form of motion to another. Temperature represents the intensity of movement, while heat represents the amount and scale of heat.
Thermal radiation conduction refers to the process of energy transfer between an object and its surrounding environment through thermal radiation. Thermal radiation refers to the electromagnetic wave radiation emitted and absorbed by an object at different temperatures. According to Stefan Boltzmann's law, the radiated power emitted by an object is proportional to the fourth power of temperature and is related to the temperature difference between the object and its surrounding environment.
Heat conduction is a heat transfer phenomenon that occurs in a medium without macroscopic motion. It can occur in solids, liquids, and gases, but strictly speaking, it is only pure heat conduction in solids. Even when a fluid is in a stationary state, natural convection occurs due to density differences caused by temperature gradients. Therefore, heat convection and heat conduction occur simultaneously in fluids.
The temperature difference within an object or system is a necessary condition for heat conduction. Or in other words, as long as there is a temperature difference within or between the media, heat transfer will definitely occur. The heat conduction rate is determined by the distribution of temperature field inside the object.
The phenomenon of heat transfer from one part of a system to another or from one system to another is called heat transfer. Thermal conduction is one of the three modes of heat transfer: conduction, convection, and radiation. It is the main way of heat transfer in solids, layer by layer transfer in non flowing liquid or gas layers, and often occurs simultaneously with thermal convection in flowing conditions.
Thermal radiation and thermal conduction are two types of heat transfer methods, and their difference lies in the different modes of transfer. Firstly, heat conduction refers to the transfer of heat between particles inside an object, which requires a temperature difference in the object, meaning that particles in high-temperature areas can transfer heat to particles in low-temperature areas. The speed and properties of heat conduction are related, commonly found in solids and liquids. And thermal radiation refers to the transfer of heat energy in the transmission of light, which does not require a material medium, only the energy transmitted through light. For example, the energy emitted by the sun to the earth is transmitted through thermal radiation. The speed of thermal radiation is related to temperature and is commonly found in solids, liquids, and gases. In summary, heat conduction requires the presence of a medium, and thermal energy is transferred inside an object, while thermal radiation does not require the presence of a medium, and thermal energy is transferred in the form of light.
Thermal insulation clothing, also known as thermal protective clothing, is an important personal protective equipment. It refers to protective clothing that can prevent itself from being ignited, burning with flames, and smoldering when in contact with flames and hot objects, and protect the human body from various injuries. It is divided into protective clothing for high-temperature furnace operations in industries such as petroleum, chemical, metallurgy, and glass, as well as firefighting clothing used for firefighting and forest fire prevention.
Thermal insulation clothing is a protective garment worn by firefighters and high-temperature workers when working near a fire. It has the characteristics of fire prevention, insulation, wear resistance, folding resistance, flame retardancy, and anti radiation heat. The anti radiation heat temperature can reach up to 1000 ℃. It is divided into two types: split type ordinary type and split type back breathing apparatus type.
Special protective clothing worn by firefighters during firefighting and rescue operations when exposed to strong radiation heat near the flame area, used to provide insulation protection for their upper and lower torso, head, hands, and feet, including insulation jackets, insulation pants, insulation headgear, insulation gloves, and insulation foot covers
Our company has recently developed an SGJ335A radiation heat conduction tester to test the insulation performance of horizontally placed insulation clothing exposed to radiation heat sources. Color touch screen display and control, Chinese and English interface, menu based operation mode.
2024-08-01 17:27
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