JP5082670B2 - Burner control system - Google Patents

Description

  The present invention relates to a burner control system capable of dealing with various types of fuels having different varieties, quality, and heat quantity.

In Patent Document 1 below, even if the amount of heat of the fuel gas supplied to the gas turbine of the power plant changes drastically according to the mixing ratio of different fuels, a stable gas turbine output is maintained against the change. A heat quantity control system capable of responding to changes in the heat quantity of fuel gas that can operate the system safely and smoothly is disclosed. This calorific value control system is a calorific value control system that mitigates adverse effects caused by changes in calorific value when liquefied natural gas mixed with boil-off gas generated from a gas tank is supplied to a gas turbine. The heat quantity change is measured, and the gas for adjusting the heat quantity according to the heat quantity change is mixed with the fuel gas to obtain a gas having a stable heat quantity.
JP 2002-188460 A

  By the way, since the above-mentioned prior art stabilizes the fuel gas supplied to the gas turbine by mixing the calorific value adjusting gas, the apparatus has a calorific value adjusting gas supply system in addition to the fuel gas supplying system. Therefore, the apparatus configuration is complicated. Further, in the prior art, since it is necessary to control not only the fuel gas supply system but also the heat quantity adjusting gas supply system, the control is complicated.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to suppress the influence of fuel heat fluctuation by a simple device configuration and control.

  In order to achieve the above object, a burner control system according to a first aspect of the invention is a burner control system that controls fuel supply to a burner that burns fuel and heats an object, and detects the temperature of the object. Based on temperature detection means, heat quantity detection means for detecting the amount of heat of the fuel, fuel adjustment means for adjusting the amount of fuel supplied to the burner, detection results of the temperature detection means and detection results of the heat quantity detection means And means for controlling the fuel adjusting means in cascade so that the detection result of the temperature detecting means becomes constant.

According to the burner control system according to the first aspect of the invention, the control means changes the fuel adjustment means, the detection result detected by the temperature detection means, and the detection result of the heat quantity detection means so that the detection result of the temperature detection means becomes constant. Cascade control based on By the operation of the cascade control, the fuel adjustment means adjusts the amount of fuel supplied to the burner based on the detection result of the heat quantity detection means before the temperature of the object fluctuates, thereby simplifying the influence of the fuel heat quantity fluctuation. It can be suppressed by the configuration and control.
In this case, a simple device configuration is used in which the amount of fuel supplied to the burner is adjusted by the fuel adjusting means, instead of adjusting the amount of heat adjustment gas prepared in advance to the fuel gas in an amount corresponding to the change in the amount of heat. Control objectives can be achieved through control.

  According to a second aspect of the present invention, there is provided a burner control system for controlling a fuel supply to a burner that burns a mixed fuel composed of different types of fuel and heats the object, and detects the temperature of the object. Temperature detecting means for detecting the amount of heat of the mixed fuel, first fuel adjusting means for adjusting the amount of fuel supplied to the burner provided for each type of fuel, A second fuel adjusting means for adjusting the amount of supply to the burner; and a first fuel adjusting means for controlling the first fuel adjusting means based on the detection result of the heat quantity detecting means so that the detection result of the heat quantity detecting means becomes constant. And a second control means for controlling the second fuel adjusting means so that the detection result of the temperature detection means becomes constant based on the detection result of the temperature detection means. Adopt That.

  According to the burner control system according to the second aspect of the present invention, the amount of heat generated by different types of fuel by controlling the fuel supply to the burner that burns the mixed fuel composed of different types of fuel and heats the object. Therefore, it is possible to stabilize the burner combustion output. The details are as follows.

  The calorific value of the mixed fuel is detected by the calorific value detection means. The first fuel adjusting means is controlled by the first control means so that the detection result by the heat quantity detecting means becomes constant. The first fuel adjusting means is provided for each type of fuel and adjusts the amount of each fuel supplied to the burner. Then, the second control means is controlled by the second control means so that the detection result of the temperature detection means becomes constant. The second fuel adjusting means adjusts the supply amount of the mixed fuel to the burner. As described above, since the detection result of the temperature detecting means is constant, it is possible to stabilize the combustion output of the burner corresponding to the difference in the amount of heat caused by the different types of fuel.

  In addition to the first or second means, the burner control system according to the third invention further comprises pressure detection means for detecting the supply pressure of the fuel or mixed fuel to the burner, and the control means or the second means The control means employs control of the fuel adjustment means or the second fuel adjustment means based on the detection result of the pressure detection means in addition to the detection result of the temperature detection means.

  According to the burner control system according to the third aspect of the present invention, it is possible to stabilize the combustion output of the burner in response to the fluctuation factor of the fuel supply pressure.

  In addition to the first to third means, the burner control system according to the fourth invention employs fourth means that the burner heats the heating fluid that is the object in the heating furnace. did. According to the present invention, since the heating fluid as the object is heated in the heating furnace using the burner capable of stabilizing the combustion output, it is possible to stabilize the temperature of the heating fluid.

  According to the present invention, the simple apparatus configuration and control of adjusting the fuel supply amount to the burner by the fuel adjusting means can suppress the influence of fuel heat amount fluctuation by the simple apparatus configuration and control. Become. At this time, a complicated apparatus configuration is not required in which the heat amount adjusting gas prepared in advance is mixed with the fuel gas in an amount corresponding to the change in the heat amount.

Also, by controlling the fuel supply to the burner that heats the target object by combusting the mixed fuel composed of different types of fuel, the combustion output of the burner can be adjusted to cope with the difference in the amount of heat generated by the different types of fuel. It is possible to stabilize.
And it is possible to stabilize the combustion output of the burner corresponding to the fluctuation factors of the fuel supply pressure.
Further, since the heating fluid is heated in the heating furnace using the burner capable of stabilizing the combustion output, the temperature of the heating fluid can be stabilized.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a burner control system E1 according to the first embodiment. As shown in FIG. 1, the burner control system E1 heats a heating fluid 1 such as water in a boiler (heating furnace) 10 by a burner 4 that uses various types of fuels 2 of different varieties, quality, and heat quantity. In this system, the outlet temperature is measured by the thermometer with control function TC7, and the control of the burner 4 is controlled by the control unit 20 so that the outlet temperature is maintained at the target temperature. In addition, embodiment using the boiler 10 is only an example of this invention, and if there exists a use of the burner 4 with a constant combustion output also in other heating furnaces etc., it is possible to apply this invention.

  The burner control system E1 includes a flow meter FI6 that detects the flow rates of various types of fuel 2 and a fuel control valve 3 that can adjust the supply pressure of the fuel 2 in order to control the heating and reducing of the burner 4 by the control unit 20. A multi-fuel compatible burner 4 which is downstream of the fuel control valve 3 and injects the fuel 2 into the combustion chamber 5 in the boiler 10 while controlling the injection pressure of the fuel 2 and the like. It is configured. Further, in order to control the heating / discharging of the burner 4, a main control system using a signal corresponding to the measured temperature of the thermometer with control function TC7 and a sub-control using a signal corresponding to the measured heat quantity of the calorimeter with control function XIC9. The fuel control valve 3 is configured to be cascade-controlled by a multiple loop of the system and a sub-control system using a signal corresponding to the pressure measured by the fuel pressure gauge with control function PC8.

The fuel 2 is supplied from a fuel supply source (not shown) to the burner 4 through a continuous pipe (hereinafter referred to as “fuel system”). The connection configuration from upstream to downstream of this fuel system is as follows.
Fuel supply source → flow meter FI6 → fuel control valve 3 → fuel pressure gauge PC8 with control function → calorimeter XIC9 with control function → thermometer TC7 with control function → burner 4

The control unit 20 is a center that is the main body of control, and is an assembly of electronic circuits that input the output signals of each measuring instrument to a PID control device and the like and control the controlled object by the signal processed control output. The control unit 20 in the embodiment is distributed for each measuring instrument.
The thermometer with control function TC7 is a measuring instrument that outputs a signal corresponding to the boiler outlet temperature of the heating fluid 1 and incorporates an automatic control function.
The fuel pressure gauge with control function PC8 is a measuring instrument that outputs a signal corresponding to the supply pressure of the fuel 2 and incorporates an automatic control function.

  The calorimeter with control function XIC9 is a measuring device that outputs a signal corresponding to the amount of heat for each type of fuel, and the amount of heat for instructing the fuel control valve 3 to open the valve corresponding to the detected amount of heat for each fuel. It is an automatic control device including a microcomputer that includes a ROM that stores a different control pattern in a freely readable manner, and that outputs a control signal read from the heat quantity-specific control pattern based on the measured heat quantity.

  As described above, the control unit 20 shown in FIG. 1 has a main function by an automatic control function that is dispersedly arranged in the control function thermometer TC7, the control function calorimeter XIC9, and the control function fuel pressure gauge PC8.・ Specifies control gain and time constant in addition to cascade control of multiple loops. It is not necessary to limit to such a form, and a general purpose control device such as a “master controller”, “slave controller”, “temperature controller”, “... Each measuring instrument that detects and detects the state of the controlled object appropriately processes the control signal to adjust the valve opening degree of the fuel control valve 3, so that the control purpose can be achieved. .

Below, operation | movement of the burner control system E1 is demonstrated.
The burner control system E1 performs cascade control of the fuel control valve 3 using signals output from the thermometer TC7 with control function, the calorimeter XIC9 with control function, and the fuel pressure gauge PC8 with control function. That is, a signal corresponding to the detected temperature of the heated fluid 1 detected by the thermometer with control function TC7 at the outlet of the boiler is simply fed back to the fuel control valve 3 to quickly control the main control system that controls the valve opening. As a sub-control system for correction, correction control is performed by a signal corresponding to the amount of heat for each fuel output from the calorimeter with control function XIC9. Note that the fuel pressure gauge with control function PC8 does not necessarily have to contribute to the control.

  The burner control system E1 feedback-controls the heating / discharging of the burner 4 by the boiler outlet temperature. That is, the thermometer with control function TC7 detects the boiler outlet temperature of the heating fluid 1, outputs a signal corresponding to the detected temperature, and the main control system simply feeds back these signals to the fuel control valve 3 while fueling. The valve opening degree of the control valve 3 is controlled. At this time, if the same type of fuel is supplied, the heat generated by stable and uniform combustion continues in the burner 4 set for optimal combustion. Therefore, unless there is a disturbance that causes a sudden change in the environmental temperature, heating is performed. The boiler outlet temperature of fluid 1 is almost stabilized as set. However, if many types of fuel are burned in the same system burner 4 without taking any countermeasures, stable and uniform heat generation will occur unless the optimum combustion method is controlled according to their different varieties, quality and heat quantity. I can't get it.

  Therefore, when various types of fuel 2 having different varieties, quality, and heat quantity are appropriately burned by the burner 4 of the same system, a signal corresponding to the heat quantity for each fuel is output by the calorimeter with control function XIC9. The valve opening degree of the fuel control valve 3 is cascade-controlled by the sub-control system using the output signal of the calorimeter with control function XIC9 and other signals and the main control system using the signal output by the thermometer with control function TC7. That is, the detected temperature is simply fed back to the fuel control valve 3 by the main control system, and the valve opening is controlled with a long time constant and a large gain. A sub-control system that forms a multiple loop together with the main control system quickly corrects and controls the valve opening with a short time constant and a small gain according to the amount of heat for each fuel output from the calorimeter with control function XIC9.

  Such cascade control makes it possible to realize fine control of the optimum combustion supply amount according to the detected heat quantity of the fuel 2. For example, when it is detected by the calorimeter with control function XIC9 that the fuel 2 has been switched from a type having a large amount of heat per unit fuel to a type having a small amount of heat, the current detected temperature detected by the thermometer with control function TC7 is Even if it matches the target value, by correcting as if the temperature is insufficient, the valve opening of the fuel control valve 3 is increased to compensate for the shortage of heat, thereby enabling quick temperature compensation. Is possible.

  According to such a burner control system E1, even when various types of fuel 2 including off-gas generated in the plant are burned while being appropriately selected by the burner 4 of the same system, different fuel types, It is possible to obtain stable and uniform heat generation by automatically controlling so as to maintain the optimum amount of combustion supply according to the quality and heat quantity.

  In addition, the control function calorimeter XIC9 displays a control pattern for each fuel instructing the fuel control valve 3 to the optimum valve opening degree of the fuel control valve 3 corresponding to the detected heat quantity of the fuel 2 in a ROM (not shown) or the like. It should be stored in a readable manner. The operation in that case is as follows. First, the microcomputer built in the control function calorimeter XIC9 reads the control pattern for each fuel corresponding to the signal based on the calorie measured and output by the control function calorimeter XIC9 from the ROM. The read fuel-specific control pattern is structured so that the optimum valve opening degree corresponding to the detected amount of heat of the fuel 2 can be instructed to the fuel control valve 3.

  The fuel control valve 3 can reliably achieve the control purpose by causing the burner 4 to burn the corresponding fuel 2 by the optimum supply amount as indicated by the fuel-specific control pattern. In this case, the calorimeter with control function XIC9 can read out the optimum control pattern for each fuel from the ROM or the like by analyzing the component of the fuel 2 without calculating the heat amount. In this case, the calorimeter with control function XIC9 may be replaced with a fuel component analyzer (not shown).

  FIG. 2 is a schematic configuration diagram showing a burner control system E2 according to the second embodiment of the present invention. Here, only differences from the burner control system E1 according to the first embodiment already described with reference to FIG. 1 will be described.

In FIG. 2, the first control unit 21 has a control function for controlling the valve opening degree of the fuel control valve 3 so that the temperature signal detected by the thermometer with control function TC7 is constant.
The control function calorimeter XIC9 is inserted in the fuel system upstream of the fuel control valve 3, and further upstream than the control function calorimeter XIC9 for each fuel system that is branched and independent for each fuel type. The fuel control valves 3A and 3B inserted are controlled.
The second control unit 22 controls the fuel control valves 3A and 3B so that the signals obtained by measuring the heat amounts of the fuels 2A and 2B detected by the calorimeter with control function XIC9 are constant.

  The burner control system E2 performs the following control instead of the cascade control described along the burner control system E1 shown in FIG. First, the first control unit 21 that controls the valve opening degree of the fuel control valve 3 simply feeds back the detected temperature of the heating fluid 1 detected by the thermometer with control function TC7 at the boiler outlet to the fuel control valve 3. Therefore, correction control due to another factor is not performed. This is to make use of an existing single fuel type burner system in which the detected temperature is simply fed back to the fuel control valve 3 to control the valve opening. Then, on the upstream side of the control function calorimeter XIC9, a signal based on the heat quantity of each fuel detected by the control function calorimeter XIC9 inserted in the fuel system upstream of the existing fuel control valve 3 is used. The second control unit 22 controls the fuel control valves 3A and 3B inserted for each fuel system that is branched and independent for each type.

  According to this burner control system E2, the fuel system downstream of the fuel control valve 3 can use a conventional burner control system as usual, so that the existing single fuel type burner system can be utilized. Can easily be upgraded to a multi-fuel type. If it is not necessary to make use of the existing single fuel type burner system, the first control unit 21 for controlling the valve opening degree of the fuel control valve 3 with the temperature signal detected by the thermometer TC7 with control function and the control function The second controller 22 using the calorimeter XIC9 detection signal may be cascade-controlled using multiple loops.

  Furthermore, the first control unit 21 that controls the valve opening degree of the first fuel control valve 3 based on the temperature signal detected by the thermometer with control function TC7, and the second control signal using the detection function calorimeter XIC9 detection signal. Based on a signal corresponding to the fuel pressure detected by the fuel pressure gauge PC8 with a control function, the control unit 22 detects the pressure of the fuel 2A, 2B supplied to the burner 4, and / or The second fuel control valves 3A and 3B may be controlled.

  Regarding the means for detecting the calorie per unit volume according to the type of fuel 2A, 2B to be used by the calorimeter with control function XIC9, as the calorimeter with control function XIC9, there is a well-known automatic cylinder type control function. A calorimeter may be adopted. Alternatively, an actual measurement value obtained by actually burning the fuels 2A and 2B having a minute flow rate accurately measured by a pilot burner or the like separately from the main burner 4 and measuring the heat amount may be used. Alternatively, if there is an analysis means for analyzing the fuel in a short time without burning the sample, it may be used.

  The automatic cylinder-type calorimeter with control function corresponds to a specific measuring instrument stipulated by the Measurement Law and can be used for measuring the calorific value for transaction certification, and conforms to Japanese Industrial Standards JISM8814 and JISK2279. The calorimeter with automatic control function can be measured. Therefore, it is effective as a calorimeter with a control function that measures the amount of heat for all types of fuel, such as crude oil, heavy oil, natural gas, coal, coke, etc. over the entire fossil fuel. Specifically, the sample and oxygen are charged into the cylinder and then automatically proceeded to the water supply, temperature adjustment, ignition, recording, and drainage according to the measurement start command, and the combustion heat per gram is calculated and the amount of heat is measured. It is possible to output a signal corresponding to the actually measured value.

  The various shapes and combinations of the constituent members shown in the above-described embodiments are merely examples, and various changes can be made based on design requirements and the like without departing from the gist of the present invention. For example, the type of the boiler 10 shown as an example of the heating furnace is not limited to the once-through boiler (Z boiler) shown in FIGS. 1 and 2, and the heating fluid 1 is not limited to water, and hot oil, hydrocarbon, nitrogen Or it may be air or the like. Further, it is free to use off-gas generated in the plant as the fuel 2, or to exclusively burn or mix one of the plural types of fuels 2A and 2B. Furthermore, other storage media may be used instead of the ROM that stores the fuel-specific control patterns in a readable manner.

  As explained above, when various types of fuels 2A and 2B are appropriately selected or mixed by the burner 4 of the same system and burned, they are measured by the calorimeter XIC9 with a control function in addition to the main feedback system by the boiler temperature. Any technique that cascade-controls the fuel control valve 3 using a signal corresponding to the amount of heat per unit volume for each fuel type can be considered to be included in the present invention. As another expression, even if there is a difference in the names such as the master control system as a master and the sub-control system as a slave, it is considered to be included in the present invention.

It is a schematic structure figure showing a burner control system concerning a 1st embodiment of the present invention. It is a schematic block diagram which shows the burner control system which concerns on 2nd Embodiment of this invention.

Explanation of symbols

1 ... Heated fluid, 2, 2A, 2B ... Fuel, 3 ... Fuel control valve,
3A, 3B ... Fuel control valve, 4 ... Burner, 6 ... Flow meter FI,
7 ... Thermometer TC with control function, 8 ... Fuel pressure gauge PC with control function,
9 ... Calorimeter with control function XIC, 10 ... Boiler, 20, 21, 22 ... Control part E1, E2 ... Burner control system,

Claims (2)

In a burner control system that controls fuel supply to a burner that heats an object by burning a mixed fuel composed of different types of fuel,
Temperature detecting means for detecting the temperature of the object;
A calorific value detecting means for detecting a calorific value of the mixed fuel;
Pressure detecting means for detecting a supply pressure of the mixed fuel to the burner;
A first fuel adjusting means which is provided for each type of fuel and adjusts the supply amount of each fuel to the burner;
A second fuel adjusting means for adjusting a supply amount of the mixed fuel to the burner;
First control means for controlling the first fuel adjusting means based on the detection result of the heat quantity detection means so that the detection result of the heat quantity detection means becomes constant;
Second control means for controlling the second fuel adjustment means so that the detection result of the temperature detection means becomes constant based on the detection result of the temperature detection means and the detection result of the pressure detection means. A burner control system characterized by that. The burner control system according to claim 1, wherein the burner heats a heating fluid that is an object in a heating furnace .

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