SU1002720A1 - Method of automatic control of boilers with common steam collector - Google Patents

Description

This invention relates to the automation of thermal processes and can be used at stations with a common steam collector.

There is a method of controlling the performance of boilers operating on a common steam collector by applying a driver action from the main controller to individual thermal load controllers, while maintaining a predetermined ratio between the steam generators of the individual boilers 1.

However, this method does not take into account the number of operating burners, fans, smoke exhausters, technological limitations, the need to change the load ratio when the number of operating boilers changes, which leads to a narrowing of the station control range and a decrease in the operating efficiency of the boiler.

The closest to the proposed technical essence is the method of regulating boilers with a common steam manifold by determining the upper and lower limits of steam production, vacuum, flow rates of fuel, air and water of each boiler, using these limits as limiting parameters, measuring steam pressure in the collector and regulating the supply of fuel to one of the boilers until one of the limiting parameters reaches one of the limits, with subsequent switching of the regulating effect on the other corner boiler 23

The disadvantage of this method is the low efficiency of the regulation process due to the fact that the extreme nature of the dependence of the efficiency of the boilers on the steam production is not taken into account.

The purpose of the invention is to increase the regulation power.

Claims (1)

The goal is achieved by the fact that, according to the method of automatic control of boilers with a common steam manifold, it is determined. neither the upper and lower limits of the steam capacity, vacuum, fuel consumption, air and water of each boiler, using these limits as limiting parameters, measuring the vapor pressure in the collector and regulating the supply of fuel to one of the boilers until any limiting parameter is reached from the limits with the subsequent switching of the regulating action to the other boiler, the dependencies of the coefficient of usefulness —deistei of each boiler on the steam capacity and the steepness of both branches of these dependencies, measuring the steam output of each boiler compares it to the optimum value, and switching the regulating effect to another boiler is performed depending on the steepness of the dependencies of the efficiency factors on the steam generating capacity, while changing the steam generating capacity in the direction of the optimum value the steepness, and when the steam production changes in the direction from the optimum value to the boiler with the lowest slope. FIG. 1 shows the dependences of the efficiency of boilers on steam generating capacity; in fig. 2 is a block diagram of an automatic control system for boilers with a common steam manifold. I The dependences F, P2 and F (Fig. 1) of the efficiency factors on the steam capacity of three boilers 1, 2 and 3 (Fig. 2) have different values of optimum performance -Donr-i, DonT2. 1 HOPE and various slopes on the right and left of the optimum value. Ascending steepness, the sequence of boilers can be made up like this; to the left of the optimal value is boiler 2, boiler 3, boiler 1, to the right is boiler 2, boiler 1, boiler 3. Thus, the boiler has a higher priority on the slope to the left (right) than the other one if it is in the range closer to the end of Boilers 1-3, the number of which may be more (FIG. 2), operate on a common steam collector 4, to which steam consumers 5 are connected. The automatic control system contains individual regulators of heat load, which control supply regulator 7 fuel. The signal of the main regulator 9 is switched to the engine adjusters 8 in the required sequence. The fuel signals 10, in: -soul and water and the signals 11 on the steam output of each boiler are fed to the analog-discrete device 12, which, taking into account the state of the priority block 13, commutes signal of the main controller 9.. Priorities 14 by steepness, as well as the value of 15 optimum steam capacities of each boiler, were set in advance from the outside according to the results of commissioning works. A method for automatically controlling boilers with a common steam collector is carried out as follows. The signals of the main regulator 9 for increasing (decreasing) the steam capacity are sent to the analog-discrete device 12, to which, moreover, signals 10 are about technological limitations, signals 11 about the current steam capacities of each boiler. The analog-discrete device 12 selects a group of boilers whose technological parameters do not reach maximum (minimum) limits, compares the steam capacity of these boilers with their optimal steam capacity, and from this group selects boilers whose current steam capacity is less (more) than their optimum and together with the unit 13 priorities on the slope are selected by the boiler with the highest priority on the slope on the left (on the right), the motor controller 8 of which connects the signal of the main regulator 9. In the absence of tlov, steam capacity which is less (more) optimum, the analog-discrete device 12 together with unit 13 connects priorities slope signal of the main controller 9 to the motor 8 of the boiler setpoint, the priority of which the right (left), the smallest steepness. The engine setting unit 8 changes the setting of the individual heat load controller 6, which changes the fuel supply to the selected boiler, by means of the regulator 7. The priorities for steepness 14 and the values of 15 optimum performance are set manually by the operator according to the results of heat testing of the boilers during commissioning. As a result of the implementation of the method of automatic control of boilers with a common steam manifold, the efficiency of the boilers is maintained close to the maximum, and temporary deviations of the steam output from the optimal ones occur with the smallest loss in efficiency, which ultimately leads to improved efficiency of operation. The invention The method of automatic control of boilers with a common steam manifold by determining the upper and lower limits of performance, vacuum, consumption of fuel, air and water of each boiler, using these limits as a limit