JPS5924101A - Basic charging controller for boiler compound in boiler system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for injecting a can cleaning agent to prevent scale adhesion on water pipes in a boiler system, and in particular,
The steam load rate of the boiler system is measured over a predetermined period of time, and if the steam load rate during the measurement period is a low steam load rate that is smaller than the scheduled standard steam load rate, a steady amount of can cleaning agent is injected in advance. The present invention relates to a control device for controlling the basic injection of can cleaning agent in a boiler system, which is configured to input a basic amount of can cleaning agent into the can water.

Generally, when a boiler system is operated for a long time, the canned water becomes concentrated, so the concentration of impurities such as calcium, magnesium, and silica contained in the canned water increases, and these impurities deposit on the inner surface of the water pipes and grow into scale. It is. Since scale is a poor conductor of heat, the adhesion of scale not only reduces the efficiency of heat exchange in the boiler system, but also causes water pipes to reach high temperatures, which can eventually lead to burnout. ing.

In order to deal with such inconveniences, it is known to continuously inject a constant amount of can cleaning agent into the water supply during operation of the boiler system to prevent scale adhesion. A predetermined amount of can cleaning agent is injected into the water supply itself in advance, or a predetermined amount of can cleaning agent is put into the can water in conjunction with a water supply pump.

In addition, in order to prevent scale adhesion in the water pipes of the boiler and to minimize corrosion of the boiler system, the Peno 1 concentration of canned water in the boiler system should be adjusted to pH 11.0 to 11.8.
It is known from experience that this should be done.

Therefore, considering that the canned water in the boiler system gradually becomes concentrated as the boiler system operates, and that the rate of concentration depends on the steam load rate in the boiler system, we The constant amount of can cleaning agent to be added is determined so that the concentration of Beichi No. 1 is approximately pH 7.0 to 7.5.

That is, if the amount of can cleaning agent regularly added is excessive, the pH concentration of the feed water becomes high and the feed water becomes alkaline, and when the boiler is operated at a high steam load rate, the can water tends to become concentrated. In such a concentrated state of canned water, the concentration of impurities such as dissolved solids contained in the canned water increases and bubbles are generated on the surface of the canned water, and these bubbles leave the air-water interface and enter the steam. It is known that this can lead to carryover and damage to related equipment such as valves connected to the boiler system.To prevent such carryover,
Although it is necessary to frequently blow the canned water, blowing generally requires stopping the boiler system, which complicates boiler maintenance and management.

On the other hand, if the constant amount of can cleaning agent added is too small, the pH concentration of the feed water will be low and the feed water will become neutral, and if the boiler is operated for a long time at a low steam load rate, the concentration of can water will not be promoted. , the pH concentration of the canned water remains low for a long time and the preferred pH is 1.
It is difficult to reach 1.0 to 11.8. As a result, corrosion of the water pipes accelerates.

Therefore, at various steam load rates, a suitable pl (1
In order to improve the probability that the boiler system can be operated at 1.0 to 11.8, the steady input amount is set to a small value, and the operator monitors whether the boiler is being operated at a low steam load factor. Only in the case of low steam load, the basic input amount of can cleaning agent is added manually to the regular input amount, and as a result, during low steam load, the pH concentration of can water increases faster than before ( Suitable p
H, so that the can water does not become concentrated immediately during high steam loads.

However, if it is left to the operator to judge whether or not the boiler is operating at a low steam load rate, the judgment will be difficult and inaccurate as it requires skill, and the basic injection operation will be extremely complicated. easy to be Therefore, if the boiler is operated at a low steam load factor but no basic injection is performed, corrosion of the boiler system will accelerate, and conversely, if the boiler is operated at a high steam load factor but basic injection is performed. However, the disadvantage is that the canned water becomes concentrated more quickly, resulting in carryover.

The purpose of the present invention is to solve the following problems, based on the above-mentioned conventional technology: the difficulty in determining whether or not the basic injection of can cleaning agent is necessary, and the complexity of the basic injection operation. This is a can cleaning agent for boiler systems that measures the amount of water, determines whether or not basic injection is necessary based on the load factor, and when it is determined that basic injection is necessary, can injects the basic amount of can cleaning agent into the water pipe. The purpose is to provide a basic charging control device.

The configuration of the present invention in accordance with the above object is to measure the steam load factor of the boiler by monitoring the operating state of the heating device during a specific measurement period, and to determine the magnitude relationship between the preset reference steam load factor and the steam load factor. The system is characterized in that when it is determined that the steam load rate is low, the basic amount of can cleaning agent is automatically poured into the water pipe.

Now, prior to the detailed description of the present invention that follows, the configuration and operation of a typical small boiler system to which the configuration of the present invention can be attached will be explained as follows.

FIG. 1 fA) is a block explanatory diagram showing the configuration of such a boiler system, and a cross section of the boiler 1 is shown.

FIG. 1(B) is a sectional view taken along line AA in FIG. 1(A).

In the figure, inside the boiler 1, a large number of water pipes 1b are installed along the inner circumferential surface of the wall 1a. )
, and its upper end is also an annular upper header 1d.
(steam room), and canned water is stored in the lower part of the lower header 1C and the water pipe 1b.

A combustion chamber 1e is located in the center of the boiler 1 surrounded by water pipes 1b.
is formed. An air passage 1h communicating with a blower 1g driven by an electric motor 1f is provided in the upper part of the boiler 1, and a nozzle rod 11 and an electrode rod 1j are vertically provided in the air passage 1h.

The lower end of the combustion chamber 1e communicates with the flue 1k through the hollow portions of a large number of water pipes 1b. From the upper header 1d, the communication pipe 1
1 extends outside the wall 1a and communicates with the lower header 1C.

A water level gauge 11n and a water level detector 2 for visually displaying the canned water level are installed in the middle of the communication pipe 1;1. A water supply control section 3 is connected to the water level detection section 2, and its output terminal is connected to an electric motor 114a that drives the water supply pump 4. An inlet pipe of the water supply pump 4 communicates with a water source (not shown), and a discharge pipe thereof communicates with the lower header 1C.

Further, a vapor pressure measuring section 5 is connected to the upper part of the communication pipe 11, and its output terminal is connected to the combustion control section 6. Control signal lines 6a' to 6C' extend from the combustion control unit 6 and are connected to the electric motor 1f, the electrode rod 1j, and the fuel pump 6 (1').The inlet pipe of the fuel pump 6d' is connected to a fuel tank (not shown). The discharge pipe communicates with the nozzle rod 11. A blow pipe 1n extends from the lower header 1C and communicates with a drainage channel (not shown) via the blow cock 1p, and the upper header 1d communicates with a drainage channel (not shown). A steam pipe 1q extends and communicates with a desired steam load (not shown).

In the configuration of the boiler system described above, when generating steam, the electric a1f drives the blower 1g to forcefully feed air into the air passage 1 while applying a high voltage to the electrode rod 1j to generate steam from the tip of the nozzle rod 11. The injected fuel is ignited and combusted within the combustion chamber 1e. The high-temperature combustion gas generated by such combustion enters the open space of the water pipe 1b from the lower end of the combustion chamber 1e, passes through this, reaches the flue 11, and is exhausted.

During this time, heat exchange is carried out to heat the canned water in the water pipe 1b and turn it into steam, which is collected and accumulated in the upper header 1d and supplied to the steam load through the steam pipe 1q.

Regarding the combustion bIL control, the steam pressure in the upper header 1d is extracted through the communication pipe 11 and supplied to the steam pressure measuring section 5, and the steam pressure in the upper header 1d is set in advance. When it is detected that the lower limit vapor pressure has been reached, the lower limit vapor pressure signal is sent to the combustion control section 6. Similarly, when it is detected that the upper limit vapor pressure has been reached, the upper limit vapor pressure signal is sent to the combustion control section 6.

The combustion control unit 6 continues to consume steam and the upper header 1d
When the vapor pressure in the interior decreases and a lower limit vapor pressure signal is received from the vapor pressure needle 2111J section 5, the electric motor 1f is started through the control signal line 6a' and the blower 1g blows the air passage 1h.
After purging with air, a high voltage is applied to the electrode rod 1j through the control signal line 6b', and at the same time, the fuel pump 6d' is started through the control signal line 6c', and the fuel injected from the nozzle rod 11 is ignited and combusted. start. Further, when the steam generation continues and the steam pressure increases and the combustion control section 6 receives an upper limit steam pressure signal from the steam pressure measurement section 5, the fuel pump 6d' is stopped via the control signal line 60', Combustion is stopped by cutting off the fuel supply, and the control signal line 6. The electric motor 1f is stopped through a' to cut off the air blowing from the blower 1g.

By such intermittent control of combustion, the steam pressure in the upper header 1d can be maintained directly at the pressure A between the side pressure values set in advance as the upper and lower steam pressure limits.

In addition, in a simple device, the electric motor 1f, the fuel pump 6d
The start/stop control and the application of high voltage to the electrode rod 1j may be performed simultaneously.

Furthermore, regarding water supply control, changes in the canned water level in the air-water interface in the communication pipe 11, that is, in the water pipe 1b, are transmitted to the water level detection section 2, and the water level detection section 2 detects the canned water level set in advance. When it is detected that the lower limit water level has been reached, the lower limit water level signal is output, and similarly, when it is detected that the upper limit water level has been reached, the lower limit water level signal is output.
The upper limit water level signal is sent to the water supply control section 3.

When the canned water level in the water pipe drops due to steam consumption and a lower limit water level signal is received from the water level detection unit 2, the water supply control unit 3 starts the electric motor B14a and uses the water supply pump 4 to lower the water pipe 1b through the lower header 1C. When the canned water level rises as the water supply continues and an upper limit water level signal is received from the water level detector 2, the electric motor 4a is stopped to cut off the water supply to the water pipe 1b.

Through such intermittent water supply control, the water level of the canned water in the water pipe 1b can be maintained at a water level between the upper and lower limit water levels preset.

The intermittent control of water supply and the intermittent control of combustion are performed separately and independently from each other.

Furthermore, when blowing canned water, by opening the blow cock 1p, part or all of the canned water in the lower header 1c and the water pipe 1b can be blown out through the drain pipe 1n.

In addition, blower 1g, air passage 1h, nozzle rod 11, electrode rod 1
The burner made of Any device is fine.

Similarly, the combustion control section 6 may also be a heating control section that turns on and off the heating device.

Next, the structure and operation of the embodiment of this explanation will be explained as follows based on FIGS. 2 to 5.

FIG. 2 shows a vapor pressure detection section in an embodiment of the present invention,
It is a block diagram showing the respective configurations of a heating control section, a steam load factor measurement section, a steam load factor determination section, a measurement period signal section, and a can cleaning agent basic injection section, and in the figure, the same symbols as in FIG. 1 are used. The components represented each correspond to the components in FIG.

The vapor pressure detection unit 5 includes a pressure sensor 5a, first and second comparators 5b and 5C following the pressure sensor 5a, and potentiometers sd and se that supply voltages corresponding to the lower limit vapor pressure and the upper limit vapor pressure to each comparator, respectively. Consists of.

The heating control unit 6 has its set terminal connected to the first comparator 5b, and its resetting/soto terminal connected to the inverter 6a.
The first 7 connected to the second comparator 5C via
A flip-flop 6b, a first relay 6d connected to the positive phase output terminal of the flip-flop 6b via a dry halo C, a monostable multi-noise ibrator 6e connected to the first comparator 5b, and a set terminal thereof. a second flip-flop 6f connected to the output terminal of the multi-node inverter 6e and whose reset terminal is connected to the output terminal of the inverter 6a; and the flip-flop 6f.
and a second relay 6h connected to the positive phase output terminal of the relay via a driver 6g.

Further, the power supply lines 6a', 6b', and 6c' extending from the motor 1f, the electrode rod 1j, and the fuel valve 6d' are connected to the meter contacts r1, r1' of the first relay 6d, and the meter contacts r2 and r2 of the second relay 611, respectively. It is connected to a power source (not shown) through a start switch 1r. Note that power is supplied to the water pump driving motor 4a through a switch 1r' that is linked to the start switch 1r, and the input terminal of a timer 7a, which will be described later, can be grounded via a switch 1r'' that is also linked to the starting switch 1r. be made into

The measurement period signal section 7 includes a timer 7a whose input terminal is connected to the switch 1r'', a first monostable multivibrator 7b whose input terminal is connected to the output terminal of the timer 7a, and a first monostable multivibrator 7b whose input terminal is connected to the output terminal of the timer 7a. It consists of a second monostable multivibrator 7C connected to the positive phase output terminal of the first monostable multivibrator 1b.

The steam load factor measurement unit 8 includes a clock pulse oscillator 8a,
The flip-flop 6 of the heating control unit 6 is connected to the three input terminals.
The positive phase output terminal of f, the clock pulse oscillator 8a, and the output terminal of the timer 7a of the measurement period signal section 7 are connected to an AND gate 8b, and the output terminal of the AND gate 8b is connected to its input terminal, and the output terminal of the AND gate 8b is connected to the reset terminal. A counter 8C is connected to the complementary output terminal of the second monostable multivibrator γC of the measurement period signal section 7, and the output terminal of the counter 8C is connected to its input terminal, and the measurement period signal section 7 is connected to the sample hold terminal. and a digital-to-analog exchanger 8d to which the positive phase output terminal of the first monostable multivibrator 7b is connected.

The steam load factor measuring section 8 is followed by a steam load factor determining section 9, whose inverting input terminal is connected to the output terminal of the measuring section 8, and whose non-inverting input terminal is connected to the output terminal of the measuring section 8 via a potentiometer 9a. A comparator 9b is connected to a power supply, and a Nant gate has one input terminal connected to the comparator 9b and the other input terminal connected to the positive phase output terminal of the first monostable multivibrator 7b of the signal section 7. It consists of 9C.

The steam load rate determination section 9 is followed by a can cleaning agent basic injection section 10 . The can quenching agent basic input section 10 has an input terminal connected to a first monostable multivibrator 10a connected to the output terminal of the NAND game 9c of the steam load factor determination section 9, and a positive phase output terminal of the monostable multivibrator 10a. Relay 10c connected via driver 10b and make contact rl of relay 10c.

electric 110d connected to the power supply via
0d, and a clean can side charging pump 10e driven by the pump 0d.

FIG. 3 shows the change over time of the vapor pressure in the communication pipe 11, that is, the vapor pressure signal output from the pressure sensor 5a), the output signal of the second comparator 5c (Bl, and the output of the first comparator 5b). The signal f(,'), the "1" and "0" states (D) of the first flip-flop 6b in the heating control section 6, and the "1" and "0" states of the second flip-flop 6f during opening.
FIG. 3 is a waveform diagram showing a state [E] in comparison.

In the above configuration, the steam pressure in the communication pipe 11, that is, the steam pressure in the upper header 1d reaches the steam pressure above the cage 1, and the steam pressure output by the pressure sensor 5a (the word S1 is the third
As shown in Figure (A) a, when the upper limit setting value () corresponding to the upper limit vapor pressure number is reached, the
C reaches the reference voltage corresponding to the upper limit setting value H supplied from I) (supplied vapor pressure signal S1 force ≦ power supply power via the button yometer 5e), so as shown in Fig. 3 (B) b. Then, the output of the converter and a-later 5C is inverted to "1" and the upper limit steam ratio signal S2 is changed to "1". ”
The flip-flop 6 receives an inverted signal from 5- to "0".
B's lycete/soto terminal (this (jf-thread A), Fig. 3 (Di
As shown in c, perform IJ sesoto on this point.

Therefore, the positive phase output of the flip-flop tube 6b is determined.
0'' and the -C first 1) relay 6 via the driver 6C.
d transitions to the de-energized state, contacts r1 and rl' are formed, and the power Z source (
At the end of the connection, the blower 1g stops blowing air, and the city pole 1j stops spark discharge. At this time, the reversal signal from the input 7 Kuichitaro a is sent to the reset terminal of the second flip-flop 6f. is also supplied and reset as shown in FIG. 3(E) d.

As a result, the positive phase output of the flip-flop 6f becomes "0" and the second relay 6h also shifts to the de-energized state via the driver 6g, so the contact r2 is opened and the power supply line 60'
The power supply is cut off through the fuel valve 6d' and the fuel valve 6d' is closed.

In this state, neither air blowing by the blower 1g nor ignition by spark discharge occurs, the fuel supply is cut off, and the burner is extinguished.

As time passes after the burner is extinguished, the steam pressure increases slightly due to thermal transient phenomena and then decreases as the boiler temperature decreases, so the steam pressure signal Sl is
As shown in Figure (A) e, once it increases, the figure (A) k)
As shown in f, it decreases linearly.

When the vapor pressure signal S1 crosses the upper limit set value H as shown in FIG. 3(A) h, the output signal of the second converter 5C changes as shown in FIG. 3(B) i. Invert from "1" to "ro".

As the vapor pressure signal 81 continues to fall and decreases to the lower limit set value, as shown in FIG. Since the reference voltage corresponding to the lower limit set value supplied from the power supply is reached, the output of the comparator 5b(7) is as shown in FIG.
"o" and supplies the lower limit vapor pressure signal S3, as shown in FIG.
b is set, the first relay 6d shifts to the excited state, starts the blower 1g, and purges air into the air passage 1h.

As described above, the inverted signal from the first comparator 5b when the blower 1g is started, that is, the lower limit vapor pressure signal s3, is also supplied to the monostable multivibrator 6e, triggering it to enter the quasi-stable state. When the multivibrator 6e returns to a stable state, the third
As shown in Figure (E) 6, the second flip-flop 6f
is set.

Then, the second relay 6h becomes energized, and the contact r2
is closed and power is supplied to the fuel valve 6d' through the power supply line 6c', so the valve 6d' is opened, fuel is ejected from the fuel injection rod 11, and the burner shifts to the combustion state.

In the above operation, as shown in FIG. 3(E), the period during which the knob 6f of the flip 70 is set to "o" is the heating stop period T2, and furthermore, after the blower 1g starts, the fuel is The period tp until the valve 6d' is opened is a pre-purge period necessary to purge air inside the air passage 1h and reliably ignite the burner.

However, even during the pre-purge period tp, the third
As shown in Figure (A) p, the vapor pressure signal s1 decreases,
Figure 3 (A)
As shown in q, when the temperature decreases to the minimum value LL and then the burner starts combustion, as the temperature of the boiler increases,
Figure 3 (Al increases linearly as shown in r).

When the increasing vapor pressure signal s1 reaches the lower limit set value again, as shown in FIG. 3(C),
As shown at t, the output signal of the first comparator 5b is inverted to "1".

As the burner continues to burn, the steam pressure continues to rise,
The vapor pressure signal S1 eventually reaches the upper set point H, as shown in FIG. b', C', d'
As shown, the first and second flip-flops 6b, 6
f are reset together.

Thus, in the above operation, the flip-flop 6f is
1'' is a heating period during which combustion is occurring in the combustion chamber 1e.

Therefore, in this type of boiler system, combustion is intermittent depending on the steam load, so if the sum of the heating periods Tl or the sum of the heating stop periods T2 in a specific measurement period is measured, the steam load of the boiler rate can be detected. Then, using the steam load rate detected in this way, a high steam load rate or a low steam load rate is determined,
When it is determined that the steam load rate is low, a basic amount of can cleaning agent is added to the can water.

The operations of the measurement period signal section 7, steam load factor measurement section 8, steam load factor determination section 9, and clean can side base feeding section 10 will be described below with reference to FIG.

As shown in FIG. 4(A) a, when the start switch 1r'' linked to the start switch 1r is closed, the start command signal S4 is supplied to the timer ?a, and the timer 7a starts timing.
As shown in FIG.
'', the clock pulse of the clock pulse oscillator aa of the steam load measuring section 8 passes through the analogue 8b and is supplied to the counter 8c, and the counter 8c starts counting as shown in Fig. 4 [C]'c. The content increases over time by 1, as shown in FIG. 4(c) d.

Eventually, as shown in FIG. 4(B)e, when the heating device operating state signal S5 becomes "0", the door 8b closes.
The supply of clock pulses from the clock pulse oscillator 8a to the counter 8C is cut off.

Then, the counting operation of the counter 8C is stopped, and the counting operation of the counter 8C is stopped, and as shown in FIG.
) As shown in r, the contents of the counter 8c are temporarily stopped. Subsequently, as shown in FIG. 4 (Blg), combustion in the boiler 1 is started again and the heating device operating state signal
When becomes "1" again, as in the above-mentioned Tato, Fig. 4 (e
) The contents of counter 8C increase over time from h, and the fourth
As shown in Figure (B) i, the heating device operating state signal S5
When becomes "0", the counting operation of the counter 8c is stopped,
As shown in FIG. 4(C)j, the contents of the counter 8c are temporarily stopped.

In this way, during the measurement period '■゛3 set in the timer 7a, there is a heating period during which the heating device operating state signal S5 indicating the operating state of the heating bag surface that causes combustion to occur at the point is "1". A cumulative heating period ΣTl of '1'l is calculated.

Subsequently, as shown in FIG. 4 (GN) 1 (), when the measurement period T3 set in the timer 7a ends and the output signal S6 of the timer 7a becomes "0", the AND gate 8b closes and the clock pulse oscillator 8a The supply of clock pulses to the counter 8C is cut off, and counting by the counter 8C ends.

When the output signal S6 of the timer 7a becomes "0", the subsequent first monostable multivibrator 7b is triggered, and as shown in FIG. 1'' is output from its positive phase output terminal. In response to the rise of the sample and hold signal S7, the digital-to-analog converter 8d converts the counter 8
The accumulated heating period signal S8, which is the content thereof, is taken in from c and converted into an analog voltage accumulated heating period signal 88', and the analog signal 88' is supplied to the steam load factor determining section 9.

Thus, the cumulative heating period signal 88' is supplied to the inverting input terminal of the comparator 9b.
A reference steam load factor signal S9 preset by the potentiometer 9a, that is, an analog voltage representing a specific reference steam load factor η, is supplied to the non-inverting input terminal of b.

Here, if the cumulative heating period ΣT1 during the specific measurement period T3 set by the timer 7a is measured, this corresponds to calculating the steam load factor of the boiler. Therefore, the reference steam load factor signal S9 mentioned above is a signal whose analog voltage is set corresponding to a specific reference cumulative heating period of a specific measurement period.

Now, as shown in FIG. 4(C) +n, it is assumed that the cumulative heating period ΣTl is smaller than the standard cumulative heating period device as the standard steam load rate signal S9 (i, the controller of the steam load rate determination section 9, The <lator 9b receives a smaller pz signal at its inverting input terminal than at its non-inverting input terminal, and the
" is output. At this time, the comparator 9 which is inputted to the following NAND gate 9cl to the comparator 9b
Since the output signal of b and the sample hole toy number S6 from the monostable multibifilator 7b are both "1",
Figure 4 (Fl n l As shown, Nantes Gate 9C
, that is, the basic input command signal 810 is “1”.
” force) and “0” I are inverted.

When the basal feeding command signal S9 is reversed from "1" to "0", the monostable multivibrator 10a of the clean can side basal feeding section 10 is triggered in response to its fall, and the power cage is triggered as shown in FIG.
G) As shown in 6, monostable multivibrator 10a
The positive phase output of becomes “1” during the metastable period, and thus,
Since the relay 10c shifts to the energized state via the driver 10b, the make contact rlO is closed and the motor 10d is driven, so that the can cleaning period ΣTl' corresponding to the basic input amount is changed to the fourth one by the pump ioe. When the cumulative heating period TR is longer than the reference cumulative heating period TR, as shown by the broken line in FIG. Even if the signal 88' is supplied to the inverting input terminal of comparator 9b, it is larger than the reference steam load factor signal 89 supplied to the non-inverting input terminal, so the output of comparator 9b is not inverted and maintains "0". , Therefore, the output of the NAND game) 9c maintains "1" as shown in FIG. 4 (F') p. As a result, the monostable multivibrator 10a of the base feeding section 10 on the clean can side is not triggered, and its positive phase output is as shown in Figure 4! As shown in FIG. 4(C) and q, the value of the counter 8C is maintained at "0", so that the pump 10e is not driven and the can cleaning agent is not injected.The contents of the counter 8C are as shown in FIG. As shown in , the monostable multivibrator 7L+ is reset after the metastable time has elapsed.

In this way, in this embodiment, the steam load rate of the boiler is measured based on the cumulative heating period of the heating device measured during a specific measurement period, and only when it is determined that the steam load rate is low, the boiler is cleaned by the basic input amount. Although the agent is put into canned water, the steam load rate of the boiler may be measured based on the cumulative heating stop period.

Next, referring to FIG. 5, regarding the change characteristics of the pH concentration of canned water in the boiler, when the steam load rate is 100%
The second side in the case of 96 will be explained as follows.

Figure 5 is a graph showing time on the horizontal axis and the concentration of canned water on the vertical axis; This is an example of operating a boiler after supplying water to a water pipe. If the boiler is currently being operated with a steam load factor of 20% and the basic amount of can cleaning agent is not added, the pH concentration of the can water will gradually increase as shown by curve X. However, it is suitable for par 09 from the viewpoint of water pipe corrosion even if operated for quite a long time.
It does not reach a degree of 11.0 to 11.8.

However, in a boiler equipped with the device of this invention, the steam load factor mentioned above is measured over a measurement period of about 2 hours after the boiler starts, and at the end of the measurement period, the steam load factor is low and the load factor does not reach the standard steam load factor. If it is determined that the basic input amount is 14, the can cleaning agent will be injected at the end of the measurement period, and at that point, as shown by the broken line Y, the pH concentration of the can water will be higher than the basic input amount. As a result, storm precipitation will gradually increase. However, a suitable pH concentration of 11.0 to 11.8 can be reached in a relatively short period of time.

On the other hand, when the boiler is operated at a steam load rate of 100%, the boiler cleaner is not initially added at the end of the measurement period, but the pH concentration remains low.

The pH increases at a faster rate than the 20% load and reaches a suitable pH concentration of 11.0 to 11.8 relatively quickly.

As explained above, the present invention measures the steam load factor of the boiler during a specific measurement period after the boiler starts, and when it is determined that the steam load factor is lower than a preset reference load factor, Since the basic amount of can cleaning agent is automatically added to the water supply to which the same amount of can cleaning agent has been added, it is easy to judge whether or not basic addition is necessary, and the can cleaning agent is automatically added. Therefore, the basic injection is always carried out at the predetermined time, and the injection is not neglected. Therefore, canned water can be operated at a suitable pH concentration of 11.0 to 11.8 for various steam loads. The chances are much greater than with conventional manual dosing based on human judgment, and this makes the water pipes less susceptible to corrosion than in the past.

[Brief explanation of drawings]

Fig. 1(A) is a block diagram showing the outline of a small boiler system to which the device of the present invention can be attached, and Fig. 1(B) is a cross section of the boiler 1 taken along line A-A in Fig. 1(8)). Figure, 2nd
The figure is a block diagram showing the configuration of an embodiment of the present invention, FIG. 3 is a waveform diagram showing signals of each part of the vapor pressure detection section and heating control section of FIG. 2, and FIG. 4 is a heating control section of FIG. 2. , a waveform diagram showing the im sequence of each part of the steam load rate measuring section, the measurement period signal section, the steam load rate judgment section, and the can cleaning agent base feeding section. It is a graph showing the change in the pH concentration of canned water as a vapor load rate as an o parameter. 1... Boiler 1f... Electric motor 1g... Blower 1J... Electrode rod Ii... Fuel injection rod 5... Steam pressure detection section 6... Heating control section 6'...
・Fuel valve 7...Measurement period signal section 8...Steam load rate measurement section 9...Steam load rate judgment section 10...Basic injection of can quencher Departmental Procedures Amendment 1, Indication of Case 1933 Patent Application No. 133250 2, Title of Invention Basic injection control device for can cleaning agent in boiler system 3,
Relationship with the case of the person making the amendment Patent applicant address: 11-1-4 Haneda Asahi-cho, Ota-ku, Tokyo, Agent 5, date of amendment order: October 1, 1982 (shipment date: October 2, 1980) Day) 6. Number of inventions increased by amendment 07. Subject of amendment

Claims (1)

[Claims] In a boiler system having a heating device that heats canned water in a water pipe of the boiler, and a heating device control means that operates the heating device intermittently between an upper limit value and a lower limit value of steam pressure of the boiler set in advance, the heating device 1g and 11.1j for a predetermined measurement period via the heating control unit 6 to measure the steam load factor of the boiler; A steam load rate determination means 9 determines a low steam load rate based on the magnitude relationship, and when the steam load rate determination means 9 determines that the steam load rate is low, a basic amount of can cleaning agent is added to the water pipe. Basic loading means 10 on the clean can side to be loaded
A basic/injection control device for can cleaning agent in a boiler system, characterized by comprising: