The finned radiator is the most widely used heat exchange equipment in the gas to liquid heat exchanger. It achieves the purpose of enhancing heat transfer by adding fins to the common base tube. The base pipe can be steel pipe; stainless steel pipe; copper pipe and so on. Fins can also use steel strips; stainless steel strips, copper strips, aluminum strips, etc.
The fin heat exchanger is mainly used for air heating in the drying system and is the main equipment in the hot air device. The heat medium used in the radiator can be steam or hot water, or heat transfer oil. The working pressure of the steam is generally not more than 0.8Mpa , the temperature of the hot air is below 170°C.
The finned radiator is mainly composed of three rows of parallel spiral finned tube bundles between the air flow directions. The processing technology of the SRZ type radiating finned tube bundle is the mechanical winding method of the reverse 0.5*10 mm steel strip, which is wound around 18 mm seamless The steel pipe is then hot-dip galvanized, and stainless steel pipe and stainless steel strip can also be used to make all stainless steel heat dissipation. SRL type radiator is a finned radiator rolled with steel pipe and aluminum strip. larger.
Because the fin heat exchanger adopts mechanical winding, the contact surface between the radiating fin and the radiating pipe is large and tight, the heat transfer performance is good and stable, the air passing resistance is small, the steam or hot water flows through the steel pipe, and the heat passes through the tight winding. The fins on the steel pipe transmit the air between the fins to heat and cool the air.
Then, for the failure accident analysis of fin heat exchanger equipment, it is generally necessary to carry out failure accident investigation, technical inspection and identification, and comprehensive analysis and judgment.
The fin type radiator can be divided into winding type; string type; welding type; rolling type.
At present, the most widely used is the steel-aluminum composite finned tube, which utilizes the pressure resistance of the steel tube and the high-efficiency thermal conductivity of aluminum, and is compounded on a special machine tool. Its contact thermal resistance is almost zero under the working condition of 210℃.
The steel-aluminum composite tube has the irreplaceable advantages of other finned tube radiators.
1. Thermal performance requirements The higher the heat transfer coefficient K value of the finned radiator, the better the heat dissipation performance. The method of increasing the heat dissipation of the radiator and increasing the heat transfer coefficient of the finned radiator can be used to increase the heat dissipation area of the outer wall, increase the air flow speed around the finned radiator, and increase the radiation intensity of the radiator.
2. Economic requirements, finned radiators need less metal consumption per unit of heat to the room, the lower the cost, the better the economy. The metal thermal strength of a finned heat sink is a measure of the economics of the heat sink. Metal thermal strength refers to when the difference between the average temperature of the heat medium in the radiator and the indoor air temperature is 1°C. The heat dissipated per kilogram mass of the radiator per unit time. This indicator can be used as an indicator to measure the economy of the same material radiator. For finned radiators of various materials, the economic evaluation standard should be measured by the cost per unit of heat dissipation of the radiator (yuan/w).
3. Installation, use and process requirements The finned radiator should have a certain mechanical strength and pressure bearing capacity; the structure should be easy to combine into the required heat dissipation area, the structure size should be small, occupy less room area and space, and the finned heat dissipation The production process of the device should meet the requirements of mass production.
4. Sanitary and aesthetic requirements, smooth appearance, no dust accumulation and easy cleaning, the installation of finned radiators should not affect the appearance of the room.
5. To meet the requirements of service life, the finned radiator should not be easily corroded and damaged, and the service life should be long.