Automatic combustion control device and combustion facility comprising the same

Abstract

To provide an automatic combustion control device capable of suppressing fluctuation of a boiler evaporation amount by other preceding elements without measuring gas components of combustion outlet gas and even without calculating the boiler evaporation amount.SOLUTION: An automatic combustion control device comprises an operation amount calculation unit for boiler evaporation amount control that calculates an operation amount for controlling a boiler evaporation amount based on time series data of an economizer inlet gas heat quantity (QGei) during operation of a combustion facility A. The operation amount calculation unit calculates an operation amount (MVt) by multiplying a deviation over time of any of the time series data by a specified coefficient.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an automatic combustion control device and a combustion facility equipped with the same, and relates to, for example, control of the boiler evaporation amount in a biomass power generation facility, a waste treatment facility, and a garbage incineration facility.

Background Art

[0002] Waste has a non-uniform composition and is a mixture of solids and liquids. Therefore, it is not easy to stabilize the combustion of waste. In particular, in incinerators equipped with a boiler in the combustion furnace, many facilities generate electricity using the steam generated in the boiler, and the instability of combustion becomes a factor in the fluctuation of the power generation amount. In recent years, garbage incineration facilities have been given the role of power plants, and stabilization of the power generation amount has been demanded. Combustion control uses the boiler evaporation amount as the detected amount and the waste supply amount and the combustion air supply amount as the controlled amounts. Since the combustion rate of the waste is slow, the fluctuation of the boiler evaporation amount is large.

[0003] Patent Document 1 measures the component concentrations of oxygen and moisture in the exhaust gas discharged from the combustion furnace, estimates the carbon dioxide concentration from this measured value, obtains the estimated calorific value of the waste according to a predetermined procedure, calculates the boiler evaporation amount based on this estimated calorific value, and uses this calculated boiler calorific value as a leading factor to control the supply amount of the material to be burned and the supply amount of combustion air, thereby controlling the boiler evaporation amount.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1, it is necessary to measure the gas components of the combustion outlet gas with an oxygen concentration meter and a moisture concentration meter and use this measured value.

[0006] The present disclosure provides an automatic combustion control device and a combustion facility including the same, which can suppress fluctuations in the boiler evaporation amount with other preceding elements without calculating the boiler evaporation amount as a preceding element as in Patent Document 1 and without measuring the gas components of the combustion exhaust gas.

Means for Solving the Problems

[0007] The inventor of the present invention has found that the heat amount of combustion gas, the combustion gas amount, etc. can be used as preceding elements that have a high correlation with the boiler evaporation amount and for which measurement data by measuring instruments of existing combustion facilities can be used.

[0008] The automatic combustion control device of the present disclosure includes an operation amount calculation unit (101) for calculating an operation amount for controlling the boiler evaporation amount based on time-series data of at least one of the economizer inlet gas heat amount (QGei) and the combustion gas amount (Gei) during the operation of the combustion facility (A). The "combustion gas amount" is the amount of combustion gas discharged from the combustion furnace and is the amount of combustion gas at any location from the combustion furnace to the chimney outlet. Examples of the combustion gas amount include the exhaust gas amount at the outlet of the exhaust gas filtration device, the combustion gas amount near the chimney (also referred to as the "chimney exhaust gas amount").

[0009] The operation amount calculation unit (101) may calculate an operation amount (MV t ) by multiplying the deviation over time (deviation at a predetermined time interval) of any of the time-series data by a predetermined coefficient.

[0010] The operation amount calculation unit (101) may obtain the economizer inlet gas heat amount (QGei) [GJ / h] by Equation (1). QGei = Gei × TGei × Cpg (1) Gei [m 3 N / h] is the measured value of the combustion gas amount. For example, it may be the combustion gas amount measured at any position from the economizer outlet to near the chimney. TGei [°C] is the temperature of the combustion gas on the inlet side of the economizer. Cpg [GJ / m 3 N·°C] is the specific heat at constant pressure of the economizer inlet gas, and a preset fixed value can be used.

[0011] The combustion facility (A) of the present disclosure includes a combustion furnace (10), a boiler (12) into which the combustion gas derived from the combustion furnace (10) is introduced, an economizer (13) into which the combustion gas derived from the boiler (12) is introduced, a chimney (16) that discharges the combustion gas sent from the economizer (13) to the atmosphere, a combustible supply unit (11) for sending the combustible (W) to the combustion furnace (10), and a control unit (C1) that at least controls a combustion air supply unit (P0, P1) for sending combustion air to the combustion furnace (10). It may be provided.

[0012] The control unit (C1) adds the operation amount (MV t ) calculated by the operation amount calculation unit (101) for boiler evaporation amount control and the operation amount (MV 0 ) at a predetermined set value (SV value) of boiler evaporation amount control, and based on the added operation amount (MV 0 +MV t ), it may control the combustible supply unit (11) and the combustion air supply unit (P0, P1). According to the operation amount (MV value), the supply amount of the combustible (W) (for example, stoker conveyance speed, driving of the extrusion device, control of the transfer device, etc.) and the supply amount of the combustion air (for example, the amount of air supplied to the combustion furnace) are controlled.

[0013] The control unit (C1) may have the function of the automatic combustion control device (for example, the operation amount calculation unit (101) for boiler evaporation amount control).

[0014] (Effect) (1) As leading elements that can use measurement data from measuring instruments of existing combustion facilities, the calorific value of combustion gas, the amount of combustion gas, etc. can be used. (2) When using the calorific value of combustion gas as a leading element, the correlation with the boiler evaporation rate is high (for example, the correlation coefficient is 0.8 or more), and there is a leading property of about one-third with respect to the actually measured boiler evaporation rate. (3) When using the amount of combustion gas as a leading element (for example, the amount of gas near the chimney), the correlation with the boiler evaporation rate is high (for example, the correlation coefficient is 0.7 or more), and there is a leading property of about one-third with respect to the actually measured boiler evaporation rate.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0016] Some embodiments of the present invention will be described below. The embodiments described below illustrate an example of the present invention. The present invention is not limited to the following embodiments, and also includes various modified forms implemented within the scope of not changing the gist of the present invention.

[0017] (Embodiment 1) Combustion facility A is shown in FIG. 1. Combustion facility A includes a stoker-type combustion furnace 10, a combustible supply unit 11, a boiler 12, an economizer 13, a bag filter 15, a chimney 16, a control unit C1, etc.

[0018] In the stoker-type combustion furnace 10, the object to be burned W is supplied by the object-to-be-burned supply unit 11 and burned. The object-to-be-burned supply unit 11 includes, for example, a transfer device (not shown) for feeding the object to be burned W from the refuse pit to the supply port of the combustion furnace 10, an extrusion device (not shown) for extruding from the supply port to the stoker section, a stoker-type supply unit (not shown), and the like. The combustion air supply unit includes an air introduction pipe L0, L01, a fan or a blower P0, P1, P2, P3, a damper V22, and the like. The control unit C1 controls the object-to-be-burned supply unit 11 and the combustion air supply unit, and the supply amounts of each are adjusted.

[0019] The combustion gas burned in the combustion furnace 10 is sent to the boiler 12 and then sent to the economizer 13. A laser-type carbon dioxide measuring device for measuring the concentration of carbon dioxide in the combustion gas, a laser-type oxygen concentration measuring device for measuring the oxygen concentration, a temperature measuring device, and a pressure measuring device may be provided in the combustion furnace 10 or in the pipe on the way to the boiler 12. As information in the combustion furnace 10, each data such as the measured temperature, pressure, oxygen concentration, and carbon dioxide concentration is stored in the storage unit 102 and sent to the control unit C1.

[0020] The boiler 12 uses the combustion gas sent from the combustion furnace 10 to evaporate the boiler feed water and generate steam. The steam is sent to a power generation unit (not shown). The generated boiler evaporation amount is stored in the storage unit 102 as time-series data.

[0021] An inlet gas temperature measuring device T3 for measuring the temperature (TGei) of the combustion gas on the inlet side of the economizer 13 is provided. In the straight pipe inside the chimney 16, a chimney exhaust gas amount measuring device T4 for measuring the amount of combustion gas (chimney exhaust gas amount) is provided. Each time-series measurement data is stored in the storage unit 102.

[0022] The first combustion gas pipe L1 derived from the economizer 13 is connected to the bag filter 15. A fan P2 is provided in the second combustion gas pipe L2 derived from the bag filter 15 to send the combustion gas dust-removed by the bag filter 15 to the chimney 16. A circulation exhaust gas pipe L22 branches from the second combustion gas pipe L2 upstream of the fan P2. The circulation exhaust gas pipe L22 is provided with a fan P3 and a damper V22 to send the dust-removed combustion gas as circulation exhaust gas to the combustion furnace 10. The control unit C1 controls the fan P3 and the damper V22 (from open to closed) according to the state of the combustion furnace 10 to adjust the amount of combustion gas sent into the combustion furnace 10.

[0023] The control unit C1 controls the combustible supply unit 11 and the combustion air supply unit (fans P0, P1) to adjust each supply amount. The control unit C1 controls the combustible supply unit 11 and the combustion air supply unit (suction pumps P0, P1) according to the operation amount (MV 0 ) at a predetermined set value (SV value) of the boiler evaporation amount control. The control unit C1 needs to change the operation amount (MV 0 ) so that the time-series data of the evaporation amount (t / h) of the boiler 12 stored in the storage unit 102 approaches the set value (SV 0 ) of the boiler evaporation amount. For example, the boiler evaporation amount fluctuates due to fluctuations in the components of the combustible W. In this embodiment, the control unit C1 executes feedforward control using the economizer inlet gas heat quantity (QGei) as a leading factor.

[0024] The control unit C1 includes an operation amount calculation unit 101 for boiler evaporation amount control. The operation amount calculation unit 101 performs the following calculations.

[0025] The economizer inlet gas heat quantity (QGei) [GJ / h] is obtained by Equation (1). QGei = Gei × TGei × Cpg (1) Gei [m 3 N / h] is the amount of combustion gas measured near the chimney. TGei [°C] is the temperature of the combustion gas on the economizer inlet side. Cpg [GJ / m 3 N·℃] is the specific heat at constant pressure of the economizer inlet gas.

[0026] In addition, the storage unit 102 stores data on the temperature of the combustion gas measured by each of the temperature measuring devices T3 and T4 and the chimney exhaust gas volume. The operation amount calculation unit 101 reads various data from the storage unit 102 and executes the calculation of the above formula (1). Based on the time-series data of the obtained economizer inlet gas heat quantity (QGei), the operation amount calculation unit 101 calculates an operation amount for controlling the boiler evaporation amount.

[0027] In this embodiment, the operation amount calculation unit 101 multiplies the time-dependent deviation (deviation at a predetermined time interval) of the time-series data of the economizer inlet gas heat quantity (QGei) by a predetermined coefficient to obtain an operation amount (MV t ). The predetermined coefficient is an arbitrary number other than 0, such as 1, 2, etc. (including positive, negative, integer, and decimal numbers).

[0028] The control unit C1 adds the operation amount (MV t ) obtained by the operation amount calculation unit 101 and the operation amount (MV 0 ) at a predetermined set value (SV 0 ) for boiler evaporation amount control, and controls the combustible supply unit 11 and the combustion air supply units (P0, P1) based on the added operation amount (MV 0 + MV t ).

[0029] Figure 2 shows the correlation between the boiler evaporation amount (vertical axis) and the economizer inlet gas heat quantity (horizontal axis). The correlation coefficient was found to be 0.8 or more.

[0030] Figure 3 shows that the economizer inlet gas heat quantity precedes the boiler evaporation amount. The data collection time was 17 hours. Figure 4 shows that the economizer inlet gas heat quantity precedes the boiler evaporation amount. The data collection time was 3 hours. From these, a precedence of about 3 minutes was confirmed.

[0031] In this embodiment, by using the economizer inlet gas heat quantity as a leading factor, it was confirmed that the correlation with the boiler evaporation rate is high (the correlation coefficient is 0.85 or more), and there is a leading property of about one-third with respect to the measured boiler evaporation rate.

[0032] The control unit C1 and the operation amount calculation unit 101 may be composed of one or more processors, hardware such as a memory for storing programs, and a program of a control procedure. The control unit C1 and the operation amount calculation unit 101 may be composed of an information processing device, a dedicated circuit, or the like.

[0033] Examples of the "combustion furnace" include a traveling stoker and a stepped stoker. Examples of the "combustible material (fuel)" include garbage (municipal waste, household waste), industrial waste, and biomass. Biomass includes waste-based biomass (livestock manure, food waste, waste paper, pulp mill waste liquid, sewage sludge, night soil sludge, construction-generated wood, sawmill residues, etc.), unused biomass (rice straw, wheat straw, rice husks, forest residues, etc.), resource crops (carbohydrate resources, starch resources, oil resources), willow, poplar, switchgrass, etc.

[0034] (Embodiment 2) As a leading factor, the combustion gas amount (Gei) measured near the chimney is used. The operation amount calculation unit 101 multiplies the temporal deviation (deviation at a predetermined time interval) of the time series data of the combustion gas amount (chimney exhaust gas amount) measured near the chimney by a predetermined coefficient to obtain the operation amount (MV t ). The control unit C1 adds the operation amount (MV t ) obtained by the operation amount calculation unit 101 to the operation amount (MV 0 ) at a predetermined set value (SV 0 ) for boiler evaporation rate control, and controls the combustible material supply unit 11 and the combustion air supply units (P0, P1) based on the added operation amount (MV 0 + MV t ).

[0035] There is a correlation between the boiler evaporation rate and the heat quantity of the chimney exhaust gas, and the correlation coefficient is 0.75 or more, and it was confirmed that there is a precedence of about one-third with respect to the measured boiler evaporation rate.

[0036] (Alternative Embodiment) (1) The combustion facility A may be provided with a chemical agent injection device for injecting a chemical agent for filtration treatment into the first combustion gas pipe L1 on the upstream side of the exhaust gas filtration device 15. (2) The combustion facility A may not be provided with a structure for sending combustion gas as circulating exhaust gas to the combustion furnace 10. (3) The control unit C1 is not limited to a configuration having the function of an automatic combustion control device, and the automatic combustion control device may be configured as a separate device. The automatic combustion control device includes a receiving unit that receives time-series data of at least one of the economizer inlet gas heat quantity (QGei) and the combustion exhaust gas quantity, and an operation quantity (MV t ) obtained by the operation quantity calculation unit (101) for controlling the boiler evaporation rate may be provided with a transmission unit that transmits to the combustion facility (A). (4) The two preceding elements of Embodiment 1 and Embodiment 2 may be used simultaneously.

[0037] (Method and Program) The automatic combustion control method is Including an operation quantity calculation step for calculating an operation quantity for controlling the boiler evaporation rate based on time-series data of at least one of the economizer inlet gas heat quantity (QGei) and the combustion gas quantity (Gei) during the operation of the combustion facility (A). The operation quantity calculation step may multiply a time-dependent deviation (deviation at a predetermined time interval) of any of the time-series data by a predetermined coefficient to calculate an operation quantity (MV t ). The operation quantity calculation step may obtain the economizer inlet gas heat quantity (QGei) [GJ / h] by the above formula (1).

[0038] The automatic combustion control program may be a program for executing the steps of the above automatic combustion control method by one or more processors or information processing devices.

Description of Symbols

[0039] A Combustion Facility 10 Combustion Furnace 11 Combustible Supply Unit 13 Economizer 15 Bag Filter (Exhaust Gas Filtration Device) 16 Chimney C1 Control Unit 101 Operation Quantity Calculation Unit 102 Memory Unit P0, P1, P2, P3 Fans V22 Damper

Claims

1. An automatic combustion control device comprising an operation amount calculation unit for calculating an operation amount for controlling the boiler evaporation amount based on time-series data of at least one of the economizer inlet gas heat amount (QGei) and the combustion gas amount during the operation of the combustion facility.

2. The operation amount calculation unit multiplies a predetermined coefficient by the deviation over time of any of the time series data to calculate an operation amount (MV ｔ ), and the automatic combustion control device according to claim 1.

3. A combustion furnace, A boiler into which the combustion gas derived from the combustion furnace is introduced, An economizer into which the combustion gas derived from the boiler is introduced, A chimney that discharges the combustion gas sent from the economizer to the atmosphere, A control unit that controls at least a combustible supply unit and a combustion air supply unit, Comprising, The control unit comprises the automatic combustion control device according to claim 1 or 2, A combustion facility.

4. The control unit is The manipulated variable (MV ｔ ) calculated by the manipulated variable calculation unit and the manipulated variable (MV ０ ) at a predetermined set value (SV value) for boiler evaporation amount control are added, and based on the added manipulated variable (MV ０ + MV ｔ ), at least the combustible supply unit and the combustion air supply unit are controlled. The combustion facility according to claim 3.

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