为探究不同二次氮气压力对焰流温度的影响，调整二次氮气压力为2 MPa、3 MPa、4 MPa，对不同喷涂距离的焰流温度进行捕捉，如图所示。一方面，通过改变二次氮气压力可以实现焰流温度的宽幅调整，二次氮气压力越大，二次氮气注入的流量就越大，参与掺混的二次氮气就越多，因此焰流温度也就相对较低。另一方面，喷涂距离越接近喷枪管口，不同二次氮气压力下的焰流温度差越大，随着喷涂距离的不断增加，焰流温度值也在不断趋近，这表明提高二次氮气压力有助于增强焰流温度在喷涂距离上保持性。在煤油流量10L/h、氧气与一次氮气流量20 Nm3/h不变的情况下，通过改变二次氮气压力和喷涂距离，可实现焰流温度在423-1080 K范围内宽幅调节。

In order to investigate the effect of different secondary nitrogen pressure on flame flow temperature, the secondary nitrogen pressure was adjusted to 2 MPa, 3 MPa and 4 MPa to capture the flame flow temperature at different spraying distances, as shown in Fig. On the one hand, by changing the secondary nitrogen pressure can achieve a wide range of flame flow temperature adjustment, the greater the secondary nitrogen pressure, the greater the flow rate of secondary nitrogen injection, the more secondary nitrogen involved in mixing, and therefore the flame flow temperature is relatively low. On the other hand, the closer the spraying distance is to the nozzle, the greater the difference in flame flow temperature under different secondary nitrogen pressure, and the flame flow temperature value is converging with the increasing spraying distance, which indicates that increasing the secondary nitrogen pressure helps to enhance the flame flow temperature retention at the spraying distance. In the case of constant kerosene flow rate of 10 L/h, oxygen and primary nitrogen flow rate of 20 Nm3/h, the flame flow temperature can be widely adjusted in the range of 423-1080 K by changing the secondary nitrogen pressure and spraying distance.