JPH09119777A - Method and apparatus for starting heating furnace combustion facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically control a temperature rise in a furnace without operator's participation by always calculating in-furnace temperature set value based on a temperature rise pattern and in-furnace target temperature, and starting a furnace combustion facility when the actually measured value of the in-furnace temperature coincides with the in-furnace temperature set value. SOLUTION: When a target operation starting time 29 and the in-furnace target temperature 30 are given, a temperature pattern is constituted by a waste time 28 for estimating the settling time under PID control and a period of raising the in-furnace temperature set value T at the predetermined time proportional ratio up to the arrival at the waste time. In such a temperature pattern, when the temperature rising time T27 up to the arrival at a predetermined in-furnace temperature is set, in-furnace temperature set value t25 at the present time 23 is given by the in-furnace temperature set vale = target in-furnace temperature To-in-furnace temperature rising ratio dT ×(temperature rising time (t)-waste time td). In this case, the time (t) = target operation starting time-present time. Thus, the in-furnace temperature state set to the set time is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and equipment for automating the start-up work of a heating furnace facility for heating an object by the heat of combustion, and particularly to a large-scale heating furnace facility requiring a long time to start up. The present invention relates to an automatic starting method and device useful for applying to the starting work.

[0002]

2. Description of the Related Art In a heating furnace facility, when production is performed for a certain time of the day for the purpose of adjusting the production amount and the rest of the production is not performed, production is not performed. For the purpose of energy saving during the period, the temperature inside the furnace is set much lower than the temperature at the time of production to keep it warm, and the temperature inside the furnace is gradually raised for several hours before the next operation. In order to maintain the operation and to save energy further, after stopping the operation of the combustion device of the heating furnace after the production, the temperature inside the furnace is left to fall naturally and left as it is for the next production. Since several hours ago, the operation of preparing the furnace temperature by gradually increasing it has been performed.

During regular repairs, the operation of the combustion device is stopped and the temperature inside the furnace is lowered to carry out repair work, and the temperature inside the furnace is gradually raised to start production again. Operations are taking place. To raise the furnace temperature, the operator gradually raises the set value of the furnace temperature at regular intervals, or a signal generator that generates a value with a function of a predetermined pattern is used. A method is adopted in which the generated signal is supplied to a furnace temperature control device as a furnace temperature set value to gradually raise the furnace temperature.

[0004]

In the above-mentioned operation mode, in order to obtain a predetermined temperature in the furnace at the time of the next production, the operator actually drops the target furnace temperature to the actual temperature. It is necessary to judge the time when the temperature inside the furnace starts to rise from the temperature inside the furnace and gradually raise the setting of the temperature inside the furnace to perform the operation so as to obtain the predetermined temperature inside the furnace. However, there is a problem that it is difficult to reduce the number of operating personnel for labor saving. If the temperature rise is not started at an appropriate time, energy is wasted if the temperature rise start time is too early, and if the temperature rise start time is too late, the target furnace There is a problem that the internal temperature cannot be obtained.

A method of raising the temperature in the furnace in a predetermined heating pattern for the purpose of labor saving and automation of operating personnel is to generate a target value of the temperature in the furnace using a pattern generator, and use that value as the temperature in the furnace. It can be solved by inputting into the control device, but when the combustion mode shown in the above operation example is stopped and the operation mode in which the temperature in the furnace gradually decreases, etc.,
Since the furnace temperature fluctuates with time, it is difficult to automatically limit when to start the pattern generator and what kind of furnace temperature set value the pattern generation should start.

[0006]

The present invention has been made in order to practically solve these problems. (1) The temperature in the furnace is set at a predetermined time with a preset heating pattern. In the method of starting the combustion equipment of the heating furnace so that the target furnace temperature, the heating pattern,
The in-furnace temperature set value T is constantly calculated based on the target in-furnace temperature, and when the actually measured value of the in-furnace temperature matches the in-reactor temperature set value T, the furnace combustion equipment is started. How to start the heating furnace equipment.

(2) In-furnace heating device 2, in-furnace temperature measuring device 3, in-furnace temperature adjusting device 4 for calculating a regulated value of the furnace temperature by receiving signals from the device, and operation based on the adjusted value And a fuel / air flow rate control device (5, 6) and its control valves (7, 8), the combustion equipment of the heating furnace,
The furnace temperature set value T at each time is calculated based on the temperature rise pattern set from the target furnace temperature, and is compared with the actual measurement value of the furnace temperature measuring device 3 to determine the timing of coincidence between the two. The internal temperature rise start determination device 10 receives a signal from the device in which the actually measured value and the in-reactor temperature set value T coincide with each other, and sends an in-reactor temperature setting signal 11 to the in-reactor temperature control device 4 for fuel / air It is a gist of a starting device for a heating furnace combustion facility, which has an in-furnace temperature setting signal generator 9 adapted to adjust a flow rate.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of the present invention will be described below with reference to the drawings showing the embodiments. FIG. 1 is a diagram showing a configuration of an automatic starting device for heating furnace equipment constructed according to claims 1 and 2 according to the present invention, and FIG. 2 is an example showing a change in temperature inside the heating furnace. Further, FIG. 3 is a flowchart of the processing contents performed by the in-furnace temperature setting signal generator 9 and the in-reactor temperature rise activation determination device 10.

The heating furnace main body 1 is a furnace itself for charging an object to be heated into the furnace and heating it to a predetermined temperature, and an in-furnace heating device 2 is installed to raise the temperature of the heating furnace. The temperature inside the furnace is measured by the furnace temperature measuring device 3 installed in the heating furnace main body 1, and the measurement signal is transmitted to the furnace temperature adjusting device 4 so that the PID calculation processing is normally performed in the furnace temperature adjusting device 4. Then, the control value for controlling the temperature in the furnace is obtained. The control values are set in a fuel flow rate control device 5 for controlling the flow rate of fuel supplied to the furnace heating device 2 and its fuel control valve 7, and an air flow rate control device 6 for controlling the flow rate of combustion air and its air control valve 8. The temperature inside the furnace is controlled by adjusting the amount of combustion in the furnace heating device 2.

In order to start the furnace heating device 2 and raise the temperature in the furnace, the furnace temperature setting signal 11 sent from the furnace temperature setting signal generator 9 to the furnace temperature adjusting device 4 is preset. It is done by changing the pattern. The time when the in-reactor temperature setting signal generator 9 starts to operate is instructed from the in-reactor temperature rise activation determination device 10.

The operation of increasing the temperature in the furnace by starting the automatic combustion device in the same figure will be described below. The operation from the time when the previous operation is completed will be described as the sequence of operation of the present invention. When the operation is completed, the combustion in the furnace heating device 2 is stopped and the furnace temperature of the heating furnace 1 starts to gradually decrease (2 in FIG. 2).
2). At this point, the operator sets the start time 29 of the next operation and the target set temperature 30 at the time of operation to the furnace temperature setting signal generator 9
(Input 101). The in-reactor temperature rise activation determination device 10 uses the in-reactor temperature setting values T, 25 calculated by the in-reactor temperature setting signal generator 9 from the preset target operation start time 29 and target in-reactor temperature 30 at the start of operation. (Process 1
03, processing 121, processing 112) and the furnace temperature signal (processing 111) from the temperature measuring device 3 are compared (processing 11
3) It is judged that the furnace temperature increasing operation is started when the furnace temperature set values T and 25 are equal to or higher than the actual furnace temperature (decision 114), and the judgment result is generated as a furnace temperature setting signal. The signal is transmitted to the device 9 as a furnace temperature increase start signal (process 115, process 122). At this time (Processing 10
4, determination 105), the transmission of the in-furnace temperature setting signal 11 to the in-furnace temperature control device is started (processes 106 to 10).
8). The process after the process 106 in FIG. 3 is similar to the process of the temperature raising operation using the conventional signal generator.

Next, a method for determining the in-furnace temperature set values T and 25 will be described. Generally, the in-furnace temperature increase rate dt, 26 is often performed in a value proportional to the passage of time, and therefore, an example of the case of proportional to the passage of time will be described. The in-furnace temperature pattern in the case of the proportional passage of time is as shown in FIG. That is, when the target operation start time 29 and the target furnace temperature 30 are given,
It is composed of a dead time 28 that allows for the settling time in the PID control, and a period in which the furnace temperature set value T rises at a constant time proportional ratio until the dead time is reached. In the case of such a temperature pattern, when the temperature raising time T, 27 until reaching the predetermined furnace temperature is set, the furnace temperature setting values T, 25 at the present time 23 are given below. Furnace temperature set value T = target furnace temperature To-furnace temperature rise rate dT x (temperature rising time t-dead time td) where temperature rising time t = target operation start time-current time

In the example, the case where the temperature rise in the furnace is proportional to the passage of time is shown. However, a non-linear change with the passage of time, for example, an inverse function of an exponential function or a trigonometric function, is used to set the temperature inside the furnace. The values T and 25 can be obtained. For example, when raising the furnace temperature by an exponential function, the furnace temperature set value is obtained by the following calculation, and the furnace temperature set value T = target furnace temperature To × exp (−A ×
Temperature rising time t) However, A: constant determined by temperature rising rate limit of heating furnace, etc. When the temperature inside the furnace is raised by a trigonometric function, the temperature setting value inside the furnace can be obtained by the following calculation. Furnace temperature set value T = target furnace temperature To x cos (φ) where (arrival time t) ≤ (rise time B from room temperature) φ = t / B x π / 4 (arrival time t)> In case of (rise time B from room temperature) φ = π / 4

[0014]

According to the present invention, even if the temperature in the furnace of the heating furnace is gradually changed due to the stop of combustion, the temperature in the furnace for obtaining the set temperature condition at the set time It became possible to perform the raising operation automatically without the involvement of the operator.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the configuration of an automatic starting device for heating furnace equipment according to the present invention,

FIG. 2 is an explanatory diagram of how to determine a temperature setting value in a furnace,

FIG. 3 is an explanatory diagram of a relationship between a change in the temperature inside the furnace since the end of the previous operation and the elapsed time of the set value of the temperature inside the furnace.

[Explanation of symbols]

 1 Heating Furnace Body 2 Furnace Heating Device 3 Furnace Temperature Measuring Device 4 Furnace Temperature Control Device 5 Fuel Flow Rate Control Device 6 Air Flow Rate Control Device 7 Fuel Control Valve 8 Air Control Valve 9 Furnace Temperature Setting Signal Generator 1 0 Furnace Internal temperature rise start judgment device 1 1 Internal temperature setting signal 2 1 Last operation end time 2 2 Temperature drop due to natural cooling 2 3 Current time 2 4 Temperature rise start time 2 5 Internal temperature set value 2 6 Internal temperature increase rate dT 27 Temperature rise time t 28 Dead time td 29 Target operation start time 30 Target furnace temperature To

Continuation of the front page (51) Int.Cl. ⁶ Identification code Reference number in the agency FI Technical display area F27B 9/36 F27B 9/36 9/40 9/40 F27D 19/00 F27D 19/00 A

Claims (2)

[Claims] 1. A preset heating pattern,
In the method of starting the combustion equipment of the heating furnace so that the furnace temperature becomes the target furnace temperature at the scheduled time, the furnace temperature set value T is constantly calculated based on the temperature rise pattern and the target furnace temperature. Then, when the measured value of the in-furnace temperature coincides with the in-furnace temperature set value T, the incinerator combustion equipment is started up. 2. A furnace heating device 2 and a furnace temperature measuring device 3
And a furnace temperature control device 4 for calculating a control value of the furnace temperature in response to a signal from the device, and a fuel operated based on the control value.
Combustion equipment of a heating furnace comprising air flow rate control devices 5, 6 and control valves 7, 8 thereof, wherein the furnace interior at each time is based on an operation start time and a temperature rise pattern set from a target furnace temperature. The temperature set value T is calculated and compared with the actually measured value of the in-core temperature measuring device 3, and the in-reactor temperature rise start determination device 10 for determining the coincidence time between them, and the actually measured value and in-reactor temperature setting from the device When the signal in which the value T coincides is received, the in-reactor temperature setting signal 11 is transmitted to the in-reactor temperature adjusting device 4,
A starting device for heating furnace combustion equipment, comprising a furnace temperature setting signal generator 9 adapted to adjust the air flow rate.