When we calculate the heat needed for the thermal equipment, we get the size of the boiler. When we really choose the model of the boiler, we have to choose a larger one than the model, which is what we usually say is the big horse. There is not much money for the freshman model boiler, so we can extend the life of the boiler. Saving the investment in the boiler actually saves us money.
To choose a cost-effective thermal oil furnace, you need to consider the following factors:
First, consider the equipment and system conditions. For use in long-term continuous operation systems, heat-conducting oil with high thermal stability must be used; when used in intermittent operation systems, the requirements for thermal stability can be relaxed. During the outage of the equipment, heating can be considered. Maintain the corresponding temperature;
Second, consider the conditions of use. If it is used in a liquid phase system, generally choose a heat transfer oil with a boiling point higher than the use temperature, because the higher the boiling point, the lower the vapor pressure during the movement, and it is convenient to use; if it is used under gas phase conditions, it should be selected at the right time. At the use temperature, the vapor pressure is further in the range of 0.098 to 0.294 MPa (1 to 3 kgf/cm) of the heat transfer oil, such as biphenyl plus diphenyl ether low melting mixed heat transfer oil.
Third, consider economic benefits. It must be both good and cheap, and economically applicable to reduce costs.
Fourth, consider the conditions and requirements of the area of ​​use. If it is used in cold regions in the north, heat transfer oil with good low-temperature fluidity should be selected to facilitate the start-up of the equipment. In places where there are strict requirements for dangerous goods, consideration should be given to selecting safe and non-flammable fluorine products. .
Fifth, consider the use temperature. Select a suitable heat transfer oil furnace according to the temperature of use. If the temperature is between 350 and 400 °C, biphenyl and diphenyl ether low-melting mixed heat transfer oil should be used; when the temperature is between 300 and 350 °C, the choice of alkylbenzene type, dibenzyltoluene or hydrogenated terphenyl type should be considered. Heat transfer oil; when the temperature is 250~300 °C, consider alkyl naphthalene, benzyl toluene and alkylbenzene type heat transfer oil; if it is used below 250 °C, choose a relatively low price mineral heat transfer oil.

In order to improve the thermal efficiency of the heat transfer oil furnace, various analysis and research are carried out at the time of design. Through research and many years of experience of FG, it is usually found that one of the following four methods or a combination method between them can be improved. The purpose of the furnace thermal efficiency.
1. Increase the heat transfer area of ​​the convection section. Increasing the heat transfer area can increase the furnace thermal efficiency. However, in general, the heat transfer area of ​​the radiant section has an appropriate range due to the size of the grate or the shape of the burner, and it is not the best policy to excessively increase the heat transfer area of ​​the radiant section. Therefore, the method of increasing the heat transfer area of ​​the FGS in the convection section is generally adopted, thereby achieving the purpose of improving the thermal efficiency of the furnace.
2. Set the air preheater. One of the most effective measures to improve the thermal efficiency of WE high thermal oil furnaces is the use of air preheaters for heat recovery. However, the biggest problem with air preheaters is that they are prone to low temperature corrosion of materials when using sulfur-containing fuels. In order to control this corrosion to a certain extent, a minimum limit should be set for the temperature of the gold FGF in the low temperature zone according to the amount of sulfur in the fuel. For this reason, there is also a restriction on the temperature of the flue gas at the outlet of the air preheater. This will determine the highest thermal efficiency that can be achieved.
3. Use waste heat boiler for heat recovery. The waste heat boiler uses heat from the flue gas waste heat discharged from the heat transfer oil furnace to heat water or generate steam. The provision of such a waste heat boiler does not change the fuel consumption of the hot oil furnace itself, and the hot water produced by the waste heat boiler or the steam generated by the waste heat boiler can be used for production and heating, thereby indirectly saving fuel. The DGF waste heat boiler has the following effects: First, it is easy to increase the thermal efficiency of the furnace because of heat recovery by water. Second, since the flue gas of several heat transfer oil furnaces can be concentrated by FGS for heat recovery, the construction cost of unit heat recovery can be reduced.
4. Reduce the excess air rate. In the design of a heat transfer oil furnace, the thermal efficiency of the furnace can be improved by reducing the excess air rate. In order to reduce the excess air rate, an air inlet baffle is usually provided for the adjustment of the combustion air. For fuel oil or gas type hot oil furnaces, low excess air type burners can be used.
Through the above method, the thermal efficiency of the heat transfer oil furnace can be improved, the cost of the VN-like fuel is reduced, and the operation and operation cost is also reduced, but the equipment manufacturing cost is increased. Therefore, Qilian heat conduction oil furnace experts recommend that the thermal oil furnace designer should combine these factors for evaluation and analysis to determine the best thermal efficiency. The so-called optimal thermal efficiency is the minimum efficiency of the manufacturing cost of the heat transfer oil furnace, the fuel cost, the operation and operation cost, and the heat transfer oil use cost.