No. 320 heat transfer oil up to 350 ° C, when the surface temperature of the heating element reaches 200 ° C or higher may cause some oil to burn, so the heating tube used to heat the oil, its surface load is not determined by the heating wire, and It is determined by the allowable operating temperature of the tube surface.
First, the relationship between the surface temperature of the heating tubular and the oil temperature?
The temperature drop between the heating element tubular and the heated oil when heated in the circulating oil depends to a large extent on the viscosity of the oil. We tested with a tubular heater with a surface load of 2.8 w/cm2:
1. When the oil temperature is 15 °C, the surface temperature of the tube is 150 °C, and the temperature drops by 135 °C.
2. When the oil temperature is 40 °C, the surface temperature of the tube is 147 °C, and the temperature drops by 107 °C.
3. When the oil temperature is 75 °C, the surface temperature of the tube is 142 °C, and the temperature drops by 66 °C.
4, oil temperature 90 ° C, tube surface temperature: 142 ° C, temperature drop 52 ° C
5, oil temperature 100 ° C, tube surface temperature: 144 ° C, temperature drop 44 ° C
Second, the surface load of the heating tubular:
1. Oil with good fluidity, its surface load: 1 ~ 6.5W / cm2, that is, 2500W per meter of power;
2, general fluidity of the oil, its surface load: 1 ~ 4W / cm2, that is, 1500W per meter of power;
3, semi-solid and heavy oil, its surface load: ≤ 1W / cm2, that is, the power per metre ≤ 300W.
First, the heat transfer oil heating element surface load selection?
The surface load design of the heating tubular is determined according to the heat dissipation rate of the heating medium.
The surface load selection of the heat transfer oil heating tubular depends on the viscosity of the heat transfer oil, that is, the fluidity is good, and the viscosity directly affects the heat removal. The premise is that the oil near the surface of the fuel tank heating element does not burn the carbon. In the case of poor oil flow, if the surface load design is high, the temperature rises quickly, but the oil flow rate is slow. The heat can not be removed as quickly as water, the heat on the surface of the tube will accumulate, and the nearby oil will be attached to the high temperature carbonization. Heat the tube housing. At the same time, the oil temperature also affects the viscosity. The lower the oil temperature, the higher the viscosity.