Device and method of regulating melting speed of aluminum alloy smelting furnace burner

A method of regulating a melting speed of an aluminum alloy smelting furnace burner, the method being performed by a device that comprises a natural gas burner, a scum filtration assembly and an aluminum-liquid laser rangefinder;

• wherein the natural gas burner is mounted in a melting zone of an aluminum alloy smelting furnace and is configured to melt an aluminum alloy ingot disposed in the melting zone of the aluminum alloy smelting furnace into an aluminum liquid, wherein the melted aluminum liquid is stored in an aluminum-liquid thermal-insulation pool of the aluminum alloy smelting furnace;
• the scum filtration assembly comprises a ceramic tube, a ceramic filtration cylinder, and a foam ceramic filtration plate;
• wherein a bottom of the ceramic tube is connected to the ceramic filtration cylinder, the foam ceramic filtration plate is mounted inside the ceramic filtration cylinder, and the ceramic filtration cylinder is merged in the aluminum-liquid thermal-insulation pool of the aluminum alloy smelting furnace;
• the aluminum-liquid laser rangefinder is mounted above the scum filtration assembly;
• wherein the method comprises:
• setting a target melting speed of the burner;
• calculating an initial flow rate of natural gas and an initial air flow rate according to the target melting speed of the burner, wherein:
• Qni=(Vmi×Hi)/(ηmi×Hn), and Qai=Qni×αc,
• wherein, Qni is the flow rate of the natural gas (m3/h), Qai is the air flow rate (m3/h), Vmi is the target melting speed of the burner (kg/h), Hi is a theoretical calorific value for melting a unit weight of aluminum alloy (kWh/kg), ηmi is an average energy efficiency of melting the aluminum alloy, Hn is a calorific value of the natural gas (kWh/m3), αc is an air-fuel ratio coefficient;
• determining an actual melting speed of the burner;
• adjusting the flow rate of the natural gas and the air flow rate based on a difference between the actual melting speed of the burner and the target melting speed of the burner, until the actual melting speed of the burner reaches the target melting speed of the burner;
• wherein, determining the actual melting speed of the burner comprises:
• obtaining a thickness function that describes a time-dependent growth curve of a thickness of an oxide layer on the aluminum liquid in the aluminum-liquid thermal-insulation pool, and determining an oxide layer thickness at each time point according to the thickness function, wherein each time point is a time point at which the thickness of the oxide layer on the aluminum liquid is sampled for obtaining the thickness function;
• obtaining a weight function that describes a relationship between a height and a weight of the aluminum liquid in the aluminum-liquid thermal-insulation pool of the aluminum alloy smelting furnace;
• obtaining a height of the aluminum liquid in the aluminum-liquid thermal-insulation pool at each time point, wherein each time point is a time point at which the height of the aluminum liquid is sampled for obtaining the weight function;
• calculating weights of the aluminum liquid corresponding to two adjacent time points t and t−1 based on the weight function, heights of the aluminum liquid at the two adjacent time points, the oxide layer thicknesses at the two adjacent time points, and oxidation burning loss masses at the two adjacent time points;
• and
• calculating the actual melting speed of the burner based on a difference between the weights of the aluminum liquid at the two adjacent time points and a time difference between the two adjacent time points;
• wherein, the thickness function is obtained by performing following operations:
• clearing scum on the ceramic filtration cylinder and the foam ceramic filtration plate;
• within a first-time interval in which an amount of the aluminum liquid in the thermal-insulation pool is kept constant, sampling heights of the aluminum liquid at a plurality of time points to determine the thickness function which is represented as:
• H(round (t/Δt2));
• wherein a second time interval is between every two of the plurality of time points;
• wherein, t∈[0,th1] represents a sampling time point, the th1 denotes a duration of first-time interval, the Δt2 is the second-time interval, the round( ) denotes rounding to the nearest integer, and the H(.) represents the oxide layer thickness;
• wherein the weight function is obtained by performing following operations:
• obtaining a volume Vt of the ceramic filtration cylinder and the foam ceramic filtration plate;
• obtaining a distance hgd from a bottom of the ceramic tube to a bottom of the aluminum-liquid thermal-insulation pool;
• obtaining an inner diameter dgd1 and an outer diameter dgd2 of the ceramic tube;
• determining a volume function Vh(h) that describes a relationship between a volume and the height of the aluminum liquid in the aluminum-liquid thermal-insulation pool by determining a shape and a size of the aluminum-liquid thermal-insulation pool;
• determining the weight function which is represented as follows:
• Ma(h)=(Vh(h)−Vt−(h−hgd)×π/4×(dgd2×dgd2−dgd1×dgd1)ρa
• wherein, the Ma(h) is the weight function, the h is the height of the aluminum liquid, and the ρa is a density of the aluminum liquid.