JPH04128505A - Steam pressure control method of plural boiler and power generator - Google Patents

Abstract

PURPOSE:To carry out stabilized main steam pressure control in any case by providing each pressure controller for operating by load adjustment of each boiler and power generator; and selectively using either one of pressure controllers depending upon pressure or absence of the load adjustment margin of the boiler. CONSTITUTION:Six boilers 2 and five power generators 3 are operated in parallel to supply and consume high pressure steam. In this time, a steam pressure measured value measured by a stem pressure gauge 5 is compared with a boiler steam pressure value which is set in a boiler pressure regulator 6 by a pressure setting device 10 to carry out PID control operation. Its operation output is transmitted to each boiler load allocation setting device 8 as a load setting value so as to adjust a generated steam amount by each boiler 2. A steam pressure measured value is compared with a boiler steam pressure set value which is set by another boiler pressure controller 7. The value of compared result is added to a power generator load set value which is set to each adder 9 by each load setting device 11 so as to be transmitted to the power generator 3 as a load command.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is applicable to equipment that supplies and consumes high-pressure steam in paper plants, petrochemical plants, and private power plants of paper plants that operate multiple boilers and generators in parallel. The present invention relates to a steam pressure control method.

[Conventional technology] Steel plants and petrochemical plans 1 to 1 in which multiple boilers and generators are operated in parallel. As a method of controlling the steam pressure of equipment that supplies and consumes high-pressure steam in a private power plant of a paper manufacturing plant, multiple boiler load controls are operated in parallel by setting their respective load ratios under one pressure controller. Control is widely practiced.

Furthermore, a method has been proposed in which steam pressure is controlled by limiting the usage range of each boiler and controlling the order.

Furthermore, a method has also been proposed in which the steam pressure is controlled by supplementarily changing the load on the generator when the boiler supply usage range is extremely large.

[Invention or Section R to be solved] In the conventional steam pressure control using multiple boilers, in the case of a method of parallel operation by setting the load ratio of each under one pressure controller, In the case of the method of limiting the usage range of the boiler and sequentially controlling it, the problem was that if the load on the consumption side, including the generator, exceeded the boiler's supply capacity range, the boiler could no longer control the steam pressure.

In addition, in order to solve this problem, the steam pressure is controlled by changing the generator load in an auxiliary manner when the boiler's supply capacity range is exceeded. The problem was that it did not return to the value before pressure control.

The present invention aims to advantageously solve these problems.

[17 steps to solve the problem] The present invention provides a pressure control controller that adjusts the load of the boiler in pressure control to maintain one steam pressure at a power plant where a plurality of boilers and generators are operated in parallel. and a pressure control controller that adjusts the load of the generator, and automatically uses the boiler pressure controller when there is an allowance for adjusting the boiler load, and uses the generator pressure controller when there is no allowance for adjusting the boiler load. A steam pressure control method for a plurality of boilers and generators, which is characterized in that the steam pressure control method is characterized in that the steam pressure control method is characterized in that the steam pressure control method is characterized in that the output of the generator is This is a pressure control method characterized by returning to a state before starting pressure control.

"Operation" In a steam pressure control method for equipment that supplies and consumes high-pressure steam in a private power plant where multiple boilers and generators are operated in parallel, pressure control controller by adjusting the load of the boiler and pressure control by adjusting the load of the generator. When the controller roller is installed, if the load on the consumption side, including the generator, falls within the supply capacity range of the boiler, and the steam pressure is within a predetermined range for the set value, only the steam pressure can be controlled by the boiler. For pressure control by the generator, either set value tracks the measured value, fixes the control output to the reference value and stops the control, or the load on the consumption side including the generator exceeds the supply capacity range of the boiler, and the boiler If steam pressure control becomes impossible and the steam pressure deviates from a predetermined range with respect to the set value, the set value is fixed and control is started.

Next, when the pressure recovers and the control output for pressure control by the generator falls within a predetermined range with respect to the reference value, the set value is tracked to the measured value and the control output is fixed to the reference value. Stop control. Through these operations, when switching from the generator's pressure controller to the boiler's pressure controller, the generator's output returns to the value before starting pressure control 1, and when the boiler is performing pressure control, the predetermined This enables steam pressure control to operate the charger based on the load.

[Example] The present invention will be explained in more detail with reference to an example in a private power plant of a steelworks shown in FIG.

In this private power plant, six boilers 2 and five steam generators 13 are operated in parallel to supply and consume high-pressure steam. 1 is a high pressure steam heater and piping, and 4 is a steam control valve. The steam pressure value measured by the steam pressure J5 is compared with the boiler steam pressure setting value set in the boiler pressure controller 6 using the pressure setting device 10, PID control calculation is performed, and the output is adjusted to each boiler load. It is given to the distribution setter 8 as a load setting value. The boiler adjusts the amount of steam generated by this set value. On the other hand, the steam pressure value measured by H5 is compared with the boiler steam pressure setting value set in the boiler pressure controller 7 using the pressure setting device 1O, and the pressure measurement value is compared to the boiler pressure setting value. If it is within a predetermined range, the power generation Ia steam pressure setting value is tracked to the steam pressure measurement value, the control output is fixed to the reference value, and the load setter 11 adjusts the power generation value set in the adder 9. It is added to the machine load setting value and sent to the machine as a load command. In addition, if the pressure measurement value or the boiler pressure set value is outside the specified range,
Immediately, the power generation 4m steam pressure set value is fixed, PID control calculation is performed, the output is added to the generator load set value set in the adder 9 of each generator, and the result is given to the generator as a load command.

As shown in Figure 2, when the measured steam pressure value rises, the generator steam pressure set value is made to track the steam pressure set value and the control output is fixed at the reference value until it reaches a predetermined range of hllJi (me). .

Next, when the measured value reaches the upper limit of the predetermined range, the generator steam pressure set value is fixed at the upper limit of the predetermined range, PID control is started, and the control output is increased as the pressure increases by 1 to control the pressure. I do. When the pressure recovers and the measured pressure falls below the generator pressure set value, the control output gradually approaches half the value of Is the control output based on the steam pressure set value? ! Fixed to value. As shown in the figure, the sewing machine operates in the same manner as when it is rising and when sewing the bottom of the air pressure measurement value. With such a configuration, it has become possible to perform steam pressure control that effectively utilizes the facility capacity without impairing controllability.

[Effects of the Invention] As described in -1- below, according to the method of the present invention, the main steam pressure in a power plant that performs single-row rotation for power generation with a plurality of boilers,
・In the pressure control method to keep the pressure constant, a pressure control controller that adjusts the boiler load and a pressure control controller that adjusts the photoelectric load are installed, and when there is a need to adjust the boiler load, the boiler pressure control controller is When there is no load adjustment allowance, the generator's pressure control controller 1-roller is automatically used to control the main steam pressure in a stable manner under any circumstances.

In addition, if the load on the consumption side, including the generator, exceeds the supply capacity range of the boiler, the load on the generator will be automatically changed to supplement the steam pressure control. After completion, the generator load automatically returns to the value before pressure control, making effective use of equipment capacity without compromising controllability, ensuring responsiveness to load fluctuations, and always maintaining maximum efficiency. This not only saves energy, but also saves labor through complete automation.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the invention, and FIG. 2 is a diagram showing an embodiment for explaining the operation of the invention. In the figure. 1: High pressure steam header 2 Boiler 3: Generator 4 Steam adjustment method 5 Steam pressure gauge 6.7 Boiler pressure controller 8, Boiler load distribution setting device 9: Adder IO: Pressure setting device Load setting device

Claims (2)

[Claims] (1) In a pressure control method for keeping the main steam pressure constant in a power plant that operates multiple boilers and generators in parallel, there is a pressure control controller that adjusts the load of the boiler and a pressure control controller that adjusts the load of the generator. The system automatically switches to use the boiler pressure control controller when there is an allowance for boiler load adjustment, and to use the generator pressure control controller when there is no boiler load adjustment allowance. Steam pressure control method for boilers and generators. (2) In the pressure control method according to claim (1), the output of the generator returns to the value before starting the pressure control when switching from the pressure control controller of the generator to the pressure control controller of the boiler. and a generator steam pressure control method.