Classification of air heat exchangers
As we all know, China is a large country and a large country in the production of heating air heat exchangers. There are many types of radiators. The materials are divided into steel, cast iron, aluminum, copper and plastic. , plate type, airfoil, column wing type, plate wing type, flat tube type, string type, fin tube type, convection type, composite type, combined type, etc. Energy conservation and environmental protection are major issues that are of great concern to the world at present. In order to continue the rapid development of China's economy, the state has proposed a target of 50% energy saving in buildings in the near future. Some big cities such as Beijing even need to build energy savings of 65%. China's current heating energy consumption is very large, about three times that of developed countries. The energy conservation of the new word air heat exchanger should be highly valued. From the perspective of energy conservation and environmental protection, the characteristics of various air heat exchangers in China are now available for scientific selection.
1. From the perspective of production conditions, the process is simple, mechanized, high degree of automation, and energy-saving products with less energy consumption. Cast iron heat-dissipating pipe production process is complex, the total energy consumption is high, the steel air heat exchanger production process is simple, mechanized, high degree of automation, low total energy consumption and low cost.
2, from the material point of view, good thermal conductivity, fast heat dissipation, high thermal efficiency, relatively energy-saving. The thermal conductivity of various materials is ranked as follows: copper, aluminum alloy, cast aluminum, steel, cast iron, stainless steel, plastic. From the perspective of thermal efficiency, copper, aluminum, steel, and plastic are poor.
3. From the metal thermal strength index, the number is high. The metal heat intensity is the heat dissipation per unit mass of metal heat exchanger under standard test conditions. The unit is W/KG °C, which is a technical and economic indicator, reflecting the material and energy saving. Different materials and forms of air heat exchangers have different metal heat strength values, cast iron 0.3-0.4. steel 0.8-1.0 or more, aluminum 1-3 or more, obviously, aluminum, steel, and cast iron.
4. From the water capacity of the air heat exchanger, the air heat exchanger with a small ratio of water capacity to heat dissipation is energy-saving. The water capacity is small, the heating and conveying cycle energy consumption is small, the heating is fast, the efficiency is high, and the energy is saved. Steel string, steel finned tube convection air heat exchanger, copper tube convection air heat exchanger have small water capacity and energy saving. At present, some air heat exchangers that introduce large waterways are misleading, and they do not save energy.
5, the installation of thermostatic control valve, can regulate the room temperature, save energy more than 20%, install thermostatic valve, should choose the heat exchanger with fast heat dissipation and high thermal efficiency, otherwise the control is not working, it is difficult to reach the purpose of constant temperature.
6, air heat exchanger cover is not energy-saving, will reduce heat dissipation 15% -25%.
7. From the height of the air heat exchanger and the number of assembled pieces, the air heat exchanger with the film is not too high and the number of assembled pieces is small, which is advantageous for better heat dissipation and energy saving. The number of columns of the column air heat exchanger should not be too much, and the two columns and the three columns are better on one side, and the number of columns is too large to save energy. The number of columns is too large, and each column cannot be sufficiently cooled.
8, from the way of taking over, it is good to go in and out. Sometimes the heat dissipation in and out of the lower two sides will be reduced by 20%. It is now popular to concentrate in and out, in order to conceal the pipeline, the water flow inside the air heat exchanger is upward and downward, which has little effect on the heat dissipation (about 5%).
9, the building maintenance structure is well insulated, the door and window seals have good heat insulation and can use less air heat exchangers to save energy.
10. Install a heat insulation board on the wall of the air heat exchanger to reduce the heat loss of the wall and save energy.
11. Composite air heat exchangers Due to the different thermal expansion coefficients of the two metals, the thermal resistance of the composite surface increases, which reduces the amount of heat dissipation and is unfavorable for energy saving.
12. From the appearance of the outer surface coating of the air heat exchanger, the traditional silver paint can reduce the heat dissipation by about 10%, and the paint can increase the heat dissipation and save energy.
13. The internal anti-corrosion coating has poor thermal conductivity, which affects heat dissipation and is not conducive to energy saving. The internal anti-corrosion coating process is complicated, and the production environment is poor; in use, the paint may peel off and affect the quality of the heat medium.