Analysis Of Thermal Efficiency Of Small Natural Ventilation Heating Furnace

In view of the problem that the heat transfer of a new type natural ventilation furnace designed by Liaohe Oilfield is not clear and the thermal efficiency has reached the expected standard,the combination of numerical simulation and mathematical calculation is studied in this paper.First,the real model of the reheating furnace is established,and the model is simplified for the convenience of simulation,and the multi basin grid is divided in ICEM.Then,the combustion process and the heat transfer in the furnace are simulated,and the parameters of the high temperature gas,such as the physical property,flow and temperature at the entrance of the heating furnace are obtained by the combustion simulation in the high and low load state.As the initial condition of the heat transfer simulation,through the analysis of the heat transfer process,the temperature drop of the high temperature flue gas flowing through the different heat exchange components is obtained,and the component of the furnace is known,especially the top thermal stress concentration.Finally,the thermal efficiency of the reheating furnace under different working conditions is calculated by simulation and mathematical calculation,and the application is positive and negative.The equilibrium method is used to calculate the heat efficiency under different inlet temperature,inlet flow rate and crude oil flow,and the effect of different working conditions on the heat efficiency of the furnace is obtained.The study shows that the heat transfer effect of different components is different.The smoke tube makes the most obvious effect on the temperature drop of the flue gas,the temperature drop reaches 313 degrees C,the heat transfer effect of the chimney is the worst,the temperature drop of the chimney is only 9,and the top heat accumulation is not found,and the heat efficiency and the influence factors are analyzed and calculated to obtain the temperature of the heated crude oil.At less than 70 C,the maximum thermal efficiency of the reheating furnace is up to 90%,and the heat efficiency of the old type heating furnace is up to 7%.In the factors of different effects of heat efficiency,the amount of crude oil in the heating furnace has the greatest impact on the thermal efficiency,and the efficiency fluctuation can reach 12% within the range of oil quantity in single furnace treatment.On the one hand,the efficiency of the small natural ventilation furnace designed by Liaohe Oilfield is verified.On the other hand,it is of great significance to provide theoretical and practical guidance on how to realize the efficient operation of the reheating furnace in the field,and to save energy,improve the environment and promote technological innovation in Liaohe Oilfield.