JPH075979B2 - Prediction method of fuel consumption of heating furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a method for predicting the amount of fuel used in a heating furnace when, for example, gas generated in a steel mill is used as fuel for a private power plant or a heating furnace. It is about.

[Prior Art] In a steel mill, B gas is generated from a blast furnace, C gas is generated from a coke oven, and LD gas is generated from a converter. Therefore, M gas, which is a mixture of these by-product gases in a predetermined ratio, is used as fuel for the rolling mill heating furnace. On the other hand, the electric power in the office is covered by the purchased electric power purchased from the electric power company and the electric power generated by private power generation. The by-product gas is used as fuel for the private power plant, and fuel oil is added if necessary.

By the way, since the generation and use of energy in the plant are fluctuated, it is necessary to carry out operations to reduce the supply and demand loss such as the reverse transmission of electric power to the electric power company or the emission of gas from these imbalances. In order to reduce this supply and demand loss, it is necessary to predict energy fluctuations in advance and operate fluctuation absorbing equipment, such as a gas holder, corresponding to the fluctuations.

Energy fluctuations are mainly due to the use side,
Among them, the amount of gas used in rolling mills fluctuates greatly. In this case, the prediction of the amount of gas used has conventionally been based on actual results.

[Problems to be Solved by the Invention] However, in the above-described conventional prediction method, since the information such as the slab to be heated is not included, the prediction accuracy is poor.

It is an object of the present invention to provide a method for predicting the amount of fuel used in a heating furnace that can solve the above problems.

[Means for Solving Problems] The method for predicting the fuel consumption of the heating furnace according to the present invention is based on the charging schedule and charging slab data into the heating furnace, and the predicted value of the heating furnace efficiency. The position of the slab in the furnace is predicted, and the amount of fuel used for a predetermined time is predicted from the heat balance at that time.

[Operation] The charging schedule of the heating furnace, for example, classification of hot and cold pieces, and charging slab data such as slab size and cycle type are input to the computer. On the other hand, the position of the charged slab in the furnace after a predetermined time is predicted from the predicted value of the heating furnace efficiency in consideration of the actual efficiency. Then, the amount of fuel used in a predetermined time is predicted from the heat balance between the amount of heat required for slab heating and the amount of heat radiation at that time. In this way, the amount of fuel used in the heating furnace within a predetermined time can be accurately predicted in accordance with the actual situation.

[Embodiment] An example of a data transmission flow for carrying out the method of the present invention is shown in FIG.

Data is generally transmitted from the yard computer to the energy center computer via the center computer.

The slab charging schedule is sent from the yard computer to the center computer, where data is given and the slab size, hot and cold pieces classification, cycle type, etc. are transmitted to the energy center. Further, regarding the slab charging, the charging time, the charging arrangement state, the charging temperature, etc. and the rolling record are transmitted from the center computer to the energy center. In addition, information such as extraction suspension, charging suspension and abnormal operation is transmitted to the energy center.

Then, first, the position of each slab in the furnace after the time to be predicted, for example, t minutes, is predicted by predicting the heating furnace efficiency in consideration of the charging schedule, the charging slab data, and the actual result.

Thus, for example, as shown in FIG. 2, the slab position in the furnace after t minutes can be predicted.

Next, the fuel usage amount for t minutes is predicted from the heat balance at that time. The fuel consumption amount V (furnace / time) is calculated by the following equation.

Qloss: Fixed heat loss due to furnace body emission (constant per hour) Qslab: Heat input to the slab in the furnace (changes depending on heating furnace efficiency and heating / cooling piece classification) H, G: Calorific value and exhaust gas amount (almost constant for each fuel type) ) C, t: Exhaust gas specific heat and recuperator outlet exhaust gas temperature (not much different in terms of recuperator outlet temperature) Of the above equations, the one that changes significantly is Qslab, and the others are assumed to be constant values.

Here, the method of obtaining Qslab will be described, for example, in the case where cold pieces and hot pieces are mixed and charged in the furnace as shown in FIG. In this case, it is considered that the slabs are not grouped, but are grouped for each steel type, each hot / cold piece, and each charging temperature.

Qslab = (++) × heating furnace efficiency Here, it is the amount of heat required to heat the charged cold piece along the slab heating curve that is predetermined according to the steel type and the like. Is the amount of heat required to heat the heat piece charged before that along the slab heating curve predetermined by the steel type, the charging temperature, and the like. Further, is the amount of heat required to heat the cold piece charged before that along the heating curve. Here, the above and are obtained as a value obtained by dividing the total amount of heat required for heating for each slab in each group by the weight of the slab in the group.

Further, the heating furnace efficiency is obtained by correcting the representative pitch after the second heating zone, that is, the standard efficiency of each slab, with the actual rolling efficiency.

In this way, by predicting the fuel usage amount according to the slab condition in the furnace, it is possible to perform accurate prediction. In this case, it goes without saying that operation changes, breakdowns, etc. are taken into consideration.

[Advantages of the Invention] The method of predicting the fuel consumption of the heating furnace according to the present invention is as described above, and by performing a detailed prediction according to the actual situation, the prediction accuracy can be significantly improved compared to the conventional case.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a data transmission flow for carrying out the method of the present invention, and FIG. 2 is an explanatory diagram showing the relationship between the heating curve of the slab and the heating amount of heat of the slab.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Shunichi Akiyama 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Shinichiro Fukushima 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Date Main Steel Pipe Co., Ltd.

Claims (1)

[Claims] 1. A furnace position of each slab after a predetermined time is predicted based on a charging schedule into the heating furnace, charging slab data, and a predicted value of the heating furnace efficiency, and fuel is used for a predetermined time from the heat balance at that time. A method for predicting fuel consumption of a heating furnace, characterized by predicting fuel consumption.