JPS6019401B2 - Steam boiler operating system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steam boiler operation system,
More particularly, it relates to a system for operating multiple boilers using a steam accumulator.

Conventionally, when operating a plurality of boilers, as shown in FIG.
a and 2b, and while predicting the load that changes over time, each boiler is activated and stopped so as to be able to cope with the load fluctuation.

However, the steam load changes depending on the season, day, time, etc., and the exact amount of steam used cannot be known unless the steam is actually used.

Therefore, it is very difficult to judge whether to start or stop the boilers, and it is easy to run many boilers unnecessarily, or conversely, the amount of evaporation cannot keep up with load fluctuations.Furthermore, the amount of evaporation between the boilers is They had drawbacks such as interference and instability, resulting in a significant drop in efficiency. The present invention aims to provide an operation system that can efficiently operate a plurality of boilers by following load fluctuations, and detects current load fluctuations based on changes in internal pressure using a steam accumulator. , the total steam flow rate from the boiler is detected by a flow rate detector, and a plurality of boilers are operated or stopped based on the detected total flow rate, so that the required amount of steam is provided to the user. .

That is, in the present invention, the steam accumulator is
It functions as a type of flow meter, indicating changes in internal pressure according to the difference between the inflow and outflow of steam, and also has the function of a delay device to absorb load fluctuations and delay their effects on the boiler. The current load fluctuations were detected by this accumulator, and each boiler was started or stopped in sequence so that the total flow of steam from the boilers approached the average value. .

Therefore, in the present invention, there is no need to operate the boiler while predicting the amount of steam to be used, and the current negative amount.

Because you can drive multiple poiras following the
Its operating efficiency can be significantly increased. Hereinafter, embodiments of the present invention will be described in detail based on the drawings.The first embodiment shown in FIG.
c, and these boilers are steam-supplied.
It is connected to a header 12 by supply pipes 1 1 a, 1 1 b, and 11 c, to which a high pressure user 13 is connected and a low pressure user 15 is connected via a steam accumulator 14 .

Flow rate detectors 16a and 16c for detecting the steam flow rate from the boiler are connected to each of the steam supply pipes 11a to 11c, respectively, and these flow rate detectors 16a to 16c add the flow rate via flow rate transmitters 17a to 17c. The total steam flow rate from the boiler in operation is detected here and inputted to the flow rate indication adjustment device 19.

On the other hand, a pressure detection device 20 is attached to the accumulator 14, and this pressure detection device 20 detects the internal pressure of the accumulator 14, which fluctuates with load fluctuations, and detects the slope of the fluctuation curve at minute intervals. This pressure signal is input to the flow rate indicating and adjusting pupil 19.

The flow rate indication adjustment device 19 opens and closes a flow valve 22 connected to the primary steam pipe 21 of the accumulator 14 based on the flow rate signal from the flow rate adder 18 and the pressure signal from the pressure detection device 20, In addition to controlling the flow rate of steam flowing into the accumulator 14, an alarm signal or a control signal for starting or stopping the boiler is issued when the flow rate signal and the pressure signal have a specific relationship as described later. Based on this signal, the boiler is activated or stopped by manual operation or automatic operation via a suitable control mechanism.

Now, in FIG. 2, assuming that each of the boilers 10a to 10c has a capacity of 10 T/day, and further assuming that there is almost no load fluctuation in the high-pressure user 13, the steam usage in both users 13 and 15 is amount is 10
In a state of T/day or less, only the first boiler 10a is operated, and the other boilers 10b and 10c are stopped.

In this state, steam from the boiler 10a flows into the accumulator 14 while being kept constant by the flow valve 22, where it is accumulated as saturated hot water, and on the secondary side of the accumulator 14, the steam is used by the user 15. On the other hand, since the pressure valve 23 opens and closes, self-evaporation occurs within the accumulator 14, and this is supplied to the user 15 through the secondary steam pipe 24. In this state, low voltage user 1
When the load on the accumulator 5 changes, the amount of steam flowing out from the accumulator 14 increases or decreases, and the internal pressure Ap thereof also changes accordingly.

For example, due to an increase in load, the accumulator 1
When the internal pressure Ap of 4 becomes lower than the low pressure level L set as shown in FIG.
is input to the flow rate indication adjustment device 19, and a signal to open the flow rate valve 22 is issued from the flow rate indication adjustment device 19.The flow rate valve 22 is gradually opened, and the amount of flow into the accumulator 14 increases, and its internal pressure Ap becomes It returns to a normal value higher than the low pressure level L. Conversely, when the load decreases and the internal pressure Ap exceeds the separately set high pressure level, and the slope is positive, the flow valve 22 is throttled to limit the amount of steam flowing into the accumulator 14. The internal pressure Ap returns to its normal value. Now, when the load increases significantly, as shown in part A in FIG. 3B, when the internal pressure Ap of the accumulator 14 is lower than the low pressure level L and its slope is negative, When the flow valve 22 is opened, the amount of steam flowing into the accumulator 14 increases, but in this state, the flow rate of steam from the first boiler 10a detected by the flow adder 18 is as shown in FIG. 3A. If the maximum combined supply amount exceeds 10T/day, it is detected by the flow rate indication and adjustment device 19, and an alarm signal or a boiler activation signal is issued from the flow rate indication and adjustment device 19, and based on this signal, As shown in FIG. 3C, the second poller 10b is newly activated. At this time, in order to prevent interference between the two boilers 10a and 10b, the automatic combustion device of the first boiler 10a is released and the first boiler 10a is fixed in a saturated operating state. Note that the boiler 10b may be started manually, but it can also be started automatically using an activation signal. When the two pollers 10a and 10b are in operation as described above, the amount of steam flowing into the accumulator 14 increases and the internal pressure Ap rises to a normal value, making it possible to cope with load fluctuations of up to 20T/day. , Boira 10
Since a is fixed in the saturated operating state, 10 to 20T
The flow rate adjustment for load fluctuations during /day is performed by the second boiler 1.
This will be done targeting 0b.

Then, when the load increases further, the flow rate adder 18
The third boiler 10c is newly operated based on the flow rate signal from the boiler and the pressure signal from the pressure detection device 20, and the second boiler 10b is fixed in a saturated operating state.

Next, in the operating state of the three boilers, the load decreases significantly, the internal pressure Ap of the accumulator 14 becomes higher than the high pressure level, its slope becomes positive, and the total steam flow rate in the flow rate adder 18 is 20T/ If the temperature falls below 1000 yen, the flow rate indicating and adjusting device 19 issues an alarm signal or a boiler stop signal, and the third boiler 10c is stopped.

At this time, the second boiler ob is switched from a fixed state of saturated operation to an automatic combustion device. Note that the boiler can also be stopped manually or automatically. Similarly, when the load further decreases, the second boiler 10b is stopped.

These operating states are illustrated in FIGS. 3A-C.

In the second embodiment shown in FIG. 4, each boiler IQa, 10b,
Flow rate detectors 16a, 16b, 16c and flow valves 25a, 2 are installed in the steam supply pipes 11a, 11b, 11c of 10c, respectively.
5b, 25c, and a flow rate indicating and adjusting device 26a. 26b, 26c are connected to a control device 27 via a flow rate adder 18, and the control device 27 controls each steam rice cake general pipe 1 1a, 1 1b, 1 1c via a flow rate indication adjustment device 26a, 26b, 26c. In addition to controlling the steam flow rate, each boiler 10a, 10b, 10c is automatically activated and stopped in response to load fluctuations, as shown in FIG.

In this case, each boiler can be automatically fixed to and released from the saturated operating state. In addition, in FIG. 4, 28 is a pressure holding valve for keeping the primary side pressure of the accumulator 14 constant. As detailed above, according to the operation system according to the present invention, when the internal pressure of the steam accumulator deviates from a region between a specific low pressure level and a specific high pressure level, while the load fluctuation is absorbed by the steam accumulator, By opening and closing the flow valve according to the gradient, the flow rate of steam from the boiler is controlled.
Instead of having the boiler faithfully follow the steam load that changes in a complicated manner, these loads can be converted to a load that the boiler can easily follow through the accumulator, and the boiler can be operated to follow the converted load. Therefore, it is very easy to control the boiler, and moreover, by detecting the total steam flow rate flowing into the accumulator and starting or stopping multiple boilers according to this total steam flow rate, multiple boilers can be operated in a superimposed manner. , not only is there no need to perform complex load distribution as in the case of parallel operation, but
A plurality of boilers can be operated easily and efficiently without operating an unnecessarily large number of boilers or causing insufficient evaporation.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a conventional boiler system, Fig. 2 is a configuration diagram showing an embodiment of the present invention, Fig. 3 A, B, and C are diagrams for explaining its operating state, and Fig. 4 5 is a block diagram showing another embodiment of the present invention, and FIG. 5 is a diagram for explaining its operating state. 10a-10c... Boiler, 11a-11c... Steam supply pipe, 13, 15... User, 14... Steam accumulator, 16a-16c... Flow rate detector, 18...
・Flow rate adder, 20...pressure detection device, 22, 25a
~25c...Flow rate valve. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1 Connect multiple boilers to the user via a steam accumulator, connect a steam flow rate detector to the steam supply pipe from each boiler, and connect a flow rate between the boiler and the accumulator to control the steam flow rate. A valve is provided, and a pressure detection device detects the level and gradient of the internal pressure of the accumulator that changes according to load fluctuations at the user, and the internal pressure is outside the range between a preset low pressure level and a high pressure level. In this case, the flow rate of steam from the boiler is controlled by opening and closing the flow valve according to the gradient, and at the same time, the total steam flow rate from the boiler flowing into the accumulator is calculated by the flow adder connected to the flow rate detector. A steam boiler operating system characterized by detecting the total steam flow rate and operating or stopping a plurality of boilers according to the total steam flow rate.