KR20020050938A - Automatic Combustion Control System for Stoker Type Refuse Incinerator - Google Patents

Abstract

PURPOSE: A method and an apparatus for controlling the firing of waste incinerating equipment are provided to measure the quality of waste by calculating a lower heating value from incinerator operation data and comparing it with an amount of water contained in waste. CONSTITUTION: A lower heating value of waste is measured by using operation data of a universal automatic firing control system of a roller grate type waste incinerating equipment, thereby measuring the quality of waste. Then, the combustion characteristic is measured from the quality of the waste, thereby controlling combustion control factors of the incinerator. The variation of combustion state in a furnace is detected from the variation of the lower heating value. Based on the variation of combustion state, the combustion control factors in the incinerator are adjusted, thereby stabilizing the combustion state of the incinerator.

Description

Combustion control method and apparatus for grate type incineration plant {Automatic Combustion Control System for Stoker Type Refuse Incinerator}

The present invention relates to a combustion control method and apparatus of a grate-type waste incineration plant. In particular, the calcined calorific value of the waste entering the incinerator is calculated from the incinerator operation data. It is possible to achieve more stable combustion control by adjusting the control parameters of the incinerator using the method of driving the engine and the method of detecting the change of combustion state in the furnace.

Conventionally, incinerators have used a method of measuring the weight input by a crane, determining the density by measuring the volume increased at the garbage inlet by this input amount, and then measuring the quality of the garbage from this density. However, this method requires not only a measuring instrument to measure the level of waste, but also a problem that external air can flow through the inlet in the furnace because waste cannot be accumulated high in the inlet, and additional cost is required due to the measuring device. There were problems. In the conventional combustion control method (Patent Publication 2000-0059289), the driver sets the low calorific value of the waste and adjusts the input ratio of the waste according to the generation of steam, but there are problems that cannot cope with the variation of the waste quality. The change in combustion status is monitored from the change in the steam generation amount, but the steam generation amount is a change in the total calorific value generated in the incinerator, and the steam generation amount is changed according to the change of garbage characteristics as well as the waste input rate. It was difficult to control the steam generation amount by the adjustment.

The present invention targets a grate-type incinerator having stable combustion characteristics in order to secure a unique automatic combustion control technology suitable for the local reality, the structure of the grate-type incinerator is a drying zone (dry stage), combustion zone ( Combustion stage), post-combustion zone (post-combustion stage) and its combustion characteristics are very complicated. In addition, since the type, composition, classification method, and water content of wastes vary greatly according to regional characteristics and seasons, incineration technology requires unique technology through systematic research and empirical experience.

Therefore, the present invention does not use the method of measuring the calorific value by using the weight or density of the waste for the purpose of improving the above-mentioned conventional problems, and calculates the low calorific value from the incinerator operation data, the low calorific value and the moisture content of the waste It is a combustion control system of grate type waste incineration plant using the method of measuring the quality of waste in relation to FIG. 2 illustrates a method of calculating waste low calorific value from operation data, and FIG. 3 illustrates a relationship between low calorific value and waste water content measured using a direct calorific value measurement method. As can be seen in Figure 3, the low calorific value and the water content have an inverse relationship. Therefore, if the quality of the waste is measured using the present invention, the combustion characteristics of the waste can be known from the moisture content, so that the appropriate dry air and combustion air flow rate and the range of the combustion air ratio of each stage can be known. Thus, the combustion of the incinerator can be controlled more stably by correcting the set values of control variables such as waste supply speed, air flow rate or grate speed of the automatic control circuit with the waste quality measured from the low calorific value. Moreover, the change of the combustion state in an incinerator can also be measured from the low calorific value calculated | required from the operation data of an incinerator in this way. For example, if the waste that is being dried in an incinerator starts burning rapidly or is only drying without being burned, it is calculated that the low calorific value is increased or decreased instantaneously. By using the present invention, a change in the instantaneous combustion state in the incinerator can be measured from the fluctuation result of the calorific value detected from the operation state of the furnace, and can also be used for feedback control of the situation in the furnace. However, this case is the result of temporary fluctuations, and if there is a fluctuation of low calorific value in the long term, it is possible to stably and automatically control the incinerator by adjusting various research control variables as described above.

1 is a block diagram of a waste incineration plant combustion process of the present invention

2 is an explanatory diagram of a method for calculating waste heating value from operation data;

3 is the relationship between the low calorific value of the waste and the moisture content

4 is an automatic combustion control circuit diagram of a waste incineration plant of the present invention.

5 is an incinerator automatic combustion main control equipment

6 is a waste supply facility diagram

7 is a grate # 1 speed control equipment diagram

8 is a grate # 2, # 3, # 4 speed control equipment diagram

9 is a grate # 5, # 6 speed control equipment diagram

10 is a secondary combustion air supply facility diagram

11 is a grate # 2, # 3, # 4 primary combustion air supply diagram

12 is a first combustion air pressure control equipment

<Description of Symbols for Major Parts of Drawings>

(1) rubbish (1 '): rubbish accumulated on the grate

(2): garbage storage tank (3): crane

(4): Garbage hopper (5): Waste metering device

(6): furnace (7): secondary air nozzle

(8): burner (9): pressure gauge

(10) Combustion air (primary air) (11) Combustion air supply pipe

(12): non-combustible

(15): Incinerator master set value rectified signal

(16a): Incinerator Control Deviation

(16b): Incinerator Control Deviation Correction Controller (Control Value Live Steam) signal

16c: waste calorie deviation correction controller

19: incinerator exit oxygen concentration signal

(21): Grate # 1 lower primary combustion air pressure

100: Steam Master Controller

110: waste calorie correction controller

121: Grate # 1 speed controller

(122), (123), (124): grate # 2, # 3 &# 4 speed controller

125,126: Grate # 5 &# 6 Speed Controller

132, 133, 134: Grate # 2, # 3 &# 4 Primary Combustion Air Volume Controller

140: Waste Supply Main Controller

150: garbage feed speed controller

(160): secondary combustion air oxygen concentration main controller

170: secondary combustion air supply controller

180: real-time garbage low calorific value signal

The present invention is to set the target of the automatic operation of the incinerator associated with the combustion control method (UAFC-Universal Automatic Firing Control) of the grate-type waste incineration plant to transmit a signal corrected for the deviation according to the operation target and the result to various unit equipment connected to the lower part Ram feeder that supplies and transports waste into the furnace in accordance with the master control unit and the incinerator's automatic combustion main control signal (steam amount, waste input amount, low calorific value of waste, air amount, etc.) Control Unit), Grate # 1 Roller Grate Speed Control Unit, Grate # 2, # 3 &# 4 Speed Control Unit (No.2, 3 & 4 Roller Grate Speed Control Unit) and Grate # 5 &# 6 Speed Control Unit (No.2, 3 & 4 Roller Grate Speed Control Unit) Also, it is necessary to control the amount of air required to completely burn a certain amount of waste according to the main signal of incinerator automatic combustion. It consists of a secondary combustion air supply equipment, the grate # 2, # 3 and # 4 of the primary combustion air supply system and primary combustion air to the pressure of the control circuit.

(Example)

Hereinafter, the configuration and operation of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a combustion process of a grate type incineration plant, FIG. 2 shows a method of calculating waste low calorific value from operation data, and FIG. 3 shows a relationship between low calorific value and waste water content of burned waste. It is. 4 shows an automatic combustion control circuit diagram of the present invention.

1 is a schematic diagram of a process of a waste incineration plant according to the present invention. When the process is classified and described in several steps,

First, the garbage collected in each home is stored in the waste storage tank 2 of the incineration plant, and the stored waste is transferred to the waste hopper 4 using the crane 3.

Second, when the waste 1 transported to the hopper 4 is supplied into the furnace 6 by the waste quantity supply device 5 using hydraulic pressure, the waste 1 is subjected to a drying process for removing moisture from the grate # 1.

Third, when the garbage 1 'is sufficiently dried, combustion starts at the grates # 2, # 3, and # 4, and all the combustibles are oxidized, and the non-combustibles 12, which are not burned, are sufficiently cooled in the grate # 5, # 6 Is discharged out.

At this time, the waste in the furnace is moved and stirred by the grate and mixed with the combustion air to achieve complete combustion.

Figure 2 shows a method for calculating the waste low calorific value from the operating data.

The heat input into the incinerator is as follows.

-Heat input by waste Q _r = m _r × H _r

-Amount of auxiliary fuel input Q _LNG = m _LNG H _LNG

Primary Air calories Q _pa = m _pa c _{p, a} (T _pa -T _o )

Secondary air calories Q _sa = m _sa c _{p, a} (T _sa -T _o )

The heat output from the incinerator is as follows.

-The heat generated throughout the boiler Q _b = m _e [h _s (T _d ) -h _l (T _e )] + m _s [h _v (T _s ) -h _s (T _d )]

- heat the exhaust gas with the outgoing _{Q g = m g c p,} g (T g - T o)

Since the heat input from the incinerator and the heat output from the incinerator are the same, the following equation can be obtained.

Q _r = Q _LNG + Q _pa + Q _sa = Q _b + Q _g

_R Q _r = Q _b + Q _g -Q _LNG -Q _pa -Q _sa

From this, the calorific value Hr per weight of the waste can be obtained.

However, T _o : Atmospheric temperature (garbage, LNG supply temperature) T _g : Exhaust gas temperature (BEGT)

T _pa : Primary air temperature T _sa : Secondary air temperature

T _d : Temperature of the drum T _e : Economizer inlet temperature

T _s : Super Heater outlet temperature h _l : Specific Enthalpy of liquid

h _s : Specific Enthalpy of Saturation

h _v : specific Enthalpy of Vapor H _r : Calorific value of waste (LHV)

H _LNG : Calorific value of auxiliary fuel m _r : Waste flow rate

m _LNG : Auxiliary fuel flow rate m _pa : Primary air flow rate

m _sa : Secondary air flow rate m _s : Steam flow rate

m _g : Flue gas flow rate c _p : Specific Heat (const.Press.)

3 shows the relationship between the low calorific value and the water content of the waste calculated from the incinerator operation data. As can be seen from FIG. 3, the low calorific value and the water content have an inverse relationship. Therefore, if the low calorific value of the waste is measured, the combustion characteristics of the waste can be known from the moisture content, so that the appropriate dry air and combustion air flow rate and the range of the unit combustion air ratio can be known.

4 is an automatic combustion control circuit of the present invention.

-Incinerator automatic combustion main control unit

-Ram Feeder Control Unit

-No.1 Roller Grater Speed Control Unit

-Grate # 2, # 3 and # 4 Speed Control Units (No.2, 3 & 4 Roller Grate Speed Control Unit)

-Grate # 5 &# 6 Fixtures

-Secondary combustion air supply facility

-Grate # 2, # 3 &# 4 Primary Combustion Air Supply Facility

-Primary combustion air pressure control equipment

These are classified into the following.

Incinerator automatic combustion main control unit (Master Control Unit), as shown in Figure 6 incinerator master control value (Master Set Value) (K3) is to protect the facility and human life when the incinerator is the following abnormal operation and further environmental pollutants (carbon monoxide) In order to suppress the discharge, the existing set value is modified by the incinerator master set value rectified signal 15 and transmitted to various controllers connected to the lower part.

When the amount of steam produced in the waste heat boiler exceeds the maximum production capacity (110%) (limit value G3), the operation load of the waste incinerator is automatically lowered to protect the waste heat boiler and its associated equipment. Master Set Value Rectified (15) signal can reduce the amount of over-produced steam (boiler overload protection circuit).

When the high-temperature waste is introduced into the furnace during the combustion process, the furnace's temperature suddenly rises and exceeds the maximum allowable temperature (limit value G1) to automatically lower the operation load of the waste incinerator (the incinerator main set value). The temperature in the furnace can be properly maintained by the correction (Master Set Value Rectified signal 15).

When the concentration of carbon monoxide generated by incomplete combustion in the incinerator exceeds the allowable value (limit value G2), the operation load of the waste incinerator is automatically lowered in order to protect the environment and the equipment. MasterSet Value Rectified), the combustion state can be improved and carbon monoxide production can be suppressed (CO generation suppression circuit).

In the incinerator automatic combustion control, the slight deviation between the incinerator master set value (K3) and the actual amount of steam produced is calculated by the incinerator control deviation correction. Rem Feeder Speed Controller 150 connected to the bottom with a signal (Control Value Live Steam) 16b and grate # 2, # 3 &# 4 primary combustion air volume controller 132, (133) ), (134) to reduce the amount of steam variation by finely adjusting the combustion state, the deviation between the master set value (K3) and the actual amount of steam produced by the incinerator generated by the change of calories of the waste flowing into the furnace Since the output value calculated by the waste calorie deviation correction controller 110 corrects the speed of the ram feeder speed controller 150 connected to the lower portion with the waste calorie deviation correction signal 16c, It is possible to correct the deviation amount of steam according to the change.

As shown in FIG. 6, the amount of waste supplied to the furnace should be constant according to the operating load of the incinerator, and for this purpose, it is controlled by maintaining the primary combustion air pressure under the grate # 1 at a constant pressure according to the load. You can check the result. The signal corrected by the real-time waste low calorific value signal 180 in the incinerator main set value correction signal 15 as the set value of the waste supply master controller 140 in the waste supply control. Compare the primary combustion air pressure with the grate # 1 lower and the correction signal according to the deviation is transmitted for correction of the set value of the Ram Feeder Speed Controller 150. It is configured in conjunction with the same three signals.

In the incinerator automatic combustion control, the slight deviation between the incinerator master set value (K3) and the actual amount of steam produced is calculated by the incinerator control deviation correction. The signal (Control Value Live Steam) (16b) is used to correct the set value of the Ram Feeder Speed Controller (150),

The deviation between the incinerator master set value (K3) and the actual amount of steam produced by the change of the calorie of the waste introduced into the furnace is calculated by the waste calorie deviation correction controller 110. 16c is used to correct the set value of the Ram Feeder Speed Controller 150,

The incinerator master set value rectified signal 15 plays a leading role as a set value of a ram feeder speed controller 150.

The grate # 1 speed control unit (No. 1 Roller Grate Speed Control Unit) has a setting value of the grate # 1 speed controller 121 is closely related to the waste supply apparatus and the waste feed rate controller 150 is set as shown in FIG. 7. The value is linked to the set value of the grate # 1 speed controller and operated. And if the waste feeder is in the reverse stroke, the grate speed should be operated at the minimum speed to minimize the waste gap between the waste feeder and the grate # 1. When the waste feeder is switched to the forward stroke, the speed controller of the grate # 1 Operation is in normal control mode.

Grate # 2, # 3 &# 4 Roller Grate Speed Control Unit is the grate # 2, # 3 &# 4 speed controllers 122, 123, 124 as shown in FIG. ) Is set as the main signal of the incinerator's master control unit's master control unit's master set value rectified signal, and it is used to correct the incinerator's control deviation signal. Promote the complete burning of garbage.

The grate # 5, # 6 speed control unit (No.5 & 6 Roller Grate Speed Control Unit) is the setting value of the grate # 5 &# 6 speed controller 125, 126 as shown in FIG. Incinerator main control unit's incinerator master control unit's master control unit's master set value rectified signal is used to achieve complete combustion of waste by incinerator load fluctuation.

Secondary air flow control unit (Secondary Air Flow Control Unit), as shown in Figure 9, the set value of the secondary combustion air supply controller 170 is the total combustion according to the operating load (incinerator main set value correction signal 15) of the incinerator Using the secondary combustion air distribution (25% of the total air volume) as the main set value in the air supply amount, the excess air amount is corrected according to the control of the oxygen concentration main controller 160 according to the incinerator outlet oxygen, and according to the carbon monoxide concentration in the incinerator outlet. By controlling the carbon monoxide main controller (), the combustion state in the furnace can be kept constant by suppressing the generation of carbon monoxide generated when the combustion air is insufficient.

The grate # 2, # 3 &# 4 primary combustion air supply system is the set value of the grate # 2, # 3 &# 4 primary combustion air supply controller 132, 133, 134 as shown in FIG. According to the amount distributed to each grate among the total combustion air distribution (75%) (primary combustion air setpoint) 15a according to the operating load (incinerator master set value rectified signal) 15, respectively. The primary combustion airflow controller of grate # 2 and # 4 performs the control of excess air according to the oxygen concentration of the incinerator and also the deviation between the incinerator master set value (K3) and the actual amount of steam produced. In order to calibrate the incinerator control deviation correction controller (Live Steam Master Controller) 100 in operation in conjunction with the incinerator control deviation correction signal (Control Value Live Steam) (b), the incinerator load is kept constant.

In the primary combustion air pressure control system, as shown in FIG. 11, the primary combustion air pressure controller maintains a constant pressure of the primary combustion air supplied to each grate to maintain control reliability of each grate primary combustion air amount regulator. This is to improve the stable operation of the incinerator.

(Variants, applications and legal interpretations)

The present invention is not limited to the above specific preferred embodiments and modifications, and any person having ordinary skill in the art to which the present invention pertains may make various design changes without departing from the gist of the present invention as claimed in the claims. Of course, such changes are within the scope of the claims.

The present invention measures the calorific value of the waste that enters the incinerator in a grate incinerator that processes urban waste as a part of securing an automatic combustion control technology that can be incinerated and treated in a most suitable and practical manner. It is possible to provide more stable combustion conditions by adjusting the control variables of the incinerator by using the method of maintaining, the method of maintaining the combustion state stably through the data of combustion characteristics, and the method of detecting the change of combustion state in the furnace. Is effective.

Claims (5)

The low calorific value of the burning waste is calculated from the operation data of the UAFC-Universal Automatic Firing Control (Roller Grate) waste incineration plant. Measuring the quality of the waste therefrom, Adjusting combustion control parameters (flow rate and distribution ratio of primary and secondary combustion air, operation of auxiliary burner, etc.) of the incinerator by measuring combustion characteristics from the quality of the waste; Combustion control of the waste incineration plant, characterized by detecting the fluctuation of the combustion state in the furnace from the temporary change of the low calorific value and controlling the combustion control parameters of the incinerator accordingly to restore the combustion state of the incinerator stably. Way. From the operation data of the combustion control system of the grate-type waste incineration plant, the low calorific value of the burning waste is measured, and the quality of the waste is measured therefrom. And various deviations are transmitted to various controllers, and the various deviations are the correction signals 16b of the incinerator control deviation correction controller 100, and the waste supply apparatus speed controller 150 and the grate # 2, # 3 &# 4 primary combustion air amount. It is transmitted to the controllers 132, 133, and 134 to correct, and corrects the supply speed as the correction signal 16c of the waste calorie deviation correction controller 110, and corrects the main word set value correction signal of the incinerator of the waste supply main controller 140. The low calorific value signal 180 is corrected to (15) and the grate # 1 speed control equipment is connected with the set value of the grate # 1 speed controller 121 and the set value of the supply speed controller 150, and grate # 2 and # 3. , # 4 speed control grate In conjunction with the set values of the # 2, # 3, # 4 speed controllers 122, 123, 124, the grate # 5, # 6 speed control equipment is connected to the grate # 5, # 6 speed controllers 125, 126. Combustion air supply controller 170 of the secondary combustion air supply system in conjunction with the operating load (15), the main oxygen control unit 160 and the carbon monoxide main controller (), grate # 2, # 3, # 4 primary combustion The air supply system is connected to the grate # 2, # 3, and # 4 primary combustion air supply controllers 132, 133 and 134, the operating load 15 and the total combustion air distribution 15a, and the incinerator main value ( K3) is a combustion control method of the waste incineration plant, characterized in that for controlling the overall combustion in conjunction with the correction signal (16b) of the control deviation correction controller (100). The method of claim 2, The set value correction signal (15) is a combustion control method for a waste incineration plant, characterized in that for correcting the boiler overload protection circuit, the furnace overload protection circuit, CO generation suppression circuit. The method of claim 2, The waste supply speed control setting value is a small deviation between the incinerator main control value (K3) and the actual amount of steam produced in the incinerator automatic combustion control, and the output value calculated by the incinerator control deviation correction controller 100 is the incinerator control deviation correction signal 16b. Furnace is used for correction of the set value of the waste supply speed controller 150, The deviation between the incinerator main value K3 and the actual amount of steam produced by the change of the calorie of the waste introduced into the furnace is determined by the waste calorie deviation correction controller 110 as the waste calorie deviation correction signal 16c. It is used to correct the set value of the feed speed controller 150, The incinerator main control value correction signal (15) is used as a set value of the waste feed rate controller (150). Incinerator automatically sets the goal of automatic operation of incinerator related to UAFC-Universal Automatic Firing Control of Grate-type Garbage Incinerator Ram Feeder Control Unit that controls the constant supply and transfer of waste into the furnace according to the master control unit and incinerator automatic combustion main control signals (steam amount, waste input amount, low calorific value of waste, air amount, etc.) Grate # 1 Speed Control Unit (No.1 Roller Grate Speed Control Unit), Grate # 2, # 3 &# 4 Speed Control Unit (No.2, 3 & 4 Roller Grate Speed Control Unit) and Grate # 5 &# 6 Speed control equipment (No.2, 3 & 4 Roller Grate Speed Control Unit) and air volume control equipment required to completely burn a certain amount of waste according to the main signal of incinerator automatic combustion. Combustion control device of a waste incineration plant, comprising a secondary combustion air supply facility, grate # 2, # 3 &# 4 primary combustion air supply facility and primary combustion air pressure control facility.