JPS631484B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intermittent blow detection device for detecting the intermittent discharge of can water (hereinafter referred to as intermittent blow) in a boiler system, and particularly relates to an intermittent blow detection device for detecting the intermittent discharge of can water (hereinafter referred to as intermittent blow) in a boiler system. The present invention relates to a novel intermittent blow detection device that detects the execution of intermittent blow based on the level and rate of fall of the can water level and the rate of rise of the can water level during water supply work after blowing.

Generally, when a boiler system is operated for a long period of time, the canned water becomes concentrated, which increases the concentration of impurities such as calcium, magnesium, and silica contained in the canned water, which precipitates and adheres to the water pipes and grows 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 the water pipes to reach high temperatures.
It is known that this can eventually lead to burnout.

Similarly, the concentration of impurities such as can cleaning agents increases, which induces a bubble layer in the can water, and the bubbles in the bubble layer turn into water and mix into the steam, causing carryover. It is also known that this can cause damage to related equipment such as valves connected to the boiler system. In order to prevent such scale growth and carryover, once the concentration of canned water has progressed to a certain extent, a portion of the canned water is intermittently blown to replace it partially with fresh canned water. Therefore, the number and timing of blowing operations needed to be recorded in order to manage the operation of the boiler system, especially as basic data for understanding the timing of the next blowing operation.

Furthermore, during maintenance and inspection of boilers, all of the canned water is discharged (hereinafter referred to as complete blowing), and for convenience of operation management, the intermittent blowing should be recorded separately from the complete blowing. was requested.

However, in conventional boiler systems, when performing intermittent blowing work, etc., it was necessary to manually record the number and timing of the work in an operating logbook, etc., and this complicated work was often neglected. It is easy to lose historical data regarding the blowing operation, making it impossible to properly grasp the timing of the blowing operation, which in turn leads to the canned water becoming extremely concentrated, allowing scale to grow, and causing frequent carry-overs. The drawback was that there was an extremely high risk of damaging the equipment as a result.

The purpose of this invention is to solve the problem of determining the timing of intermittent blowing work based on the above-mentioned conventional technology, and to solve the problem of determining the timing of intermittent blowing work, etc., and to ensure that the level and rate of decline of the can water level during the blowing work are above a specific value, and that the water supply after the blowing work is performed. By detecting that the rising time of the water level in the can is less than a specific value and outputting an intermittent blow detection signal, the above drawback can be eliminated, and the execution of intermittent blowing can be automatically distinguished from the execution of complete blowing. An object of the present invention is to provide an intermittent blow detection device for a boiler system, which enables automatic recording of historical data regarding intermittent blow work.

The structure of the present invention in accordance with the above object is that a first and second water level sensor is provided to form a water level detection section, and during blowing work, the blowing stock is opened and the can water level in the boiler is lowered. When the first set position is reached, the first water level sensor detects this and outputs the first water level signal, and then the can water level continues to drop and the second set position below the first set position is reached. When the set position is reached, the second water level sensor detects this and outputs a second water level signal. Based on the time difference, the blow speed detection unit measures the level and rate of decrease in the can water level, and determines whether the level of decrease is large enough to obtain a second water level signal and the rate of decrease is greater than or equal to a specific rate. That is, when it is detected that the time difference between the first water level signal and the second water level signal is less than or equal to a specific time, the blow speed detection section outputs a blow speed signal and temporarily stores this signal. Then, the blow speed storage section continuously outputs the blow speed storage signal, and furthermore, when water supply work is performed immediately after blowing, the blow cock is closed, water supply to the boiler is started in response to the water supply command signal, and the canister is When the water level rises again and reaches the second set position, the second water level sensor detects this and outputs the second water level signal again, and the time difference between the water supply command signal and the second water level signal is Based on this, the blow state detection section measures the water supply time for canned water accumulated in the water pipe below the second setting position, and when this is less than a specific time, the blow state detection section , outputting a blow state detection signal, and obtaining the blow speed storage signal and the blow state detection signal simultaneously;
When the logical product of both becomes "1", the intermittent blow detection section detects the execution of the intermittent blow based on the logical product and outputs the intermittent blow detection signal. It is.

Now, before explaining the subsequent embodiments of the present invention, the structure and operation of a typical small boiler system to which the structure of the present invention can be attached will be explained as follows.

FIG. 1A is a block explanatory diagram showing the configuration of such a boiler system, and a cross section of the boiler 1 is shown. FIG. 1B is a sectional view taken along the line AA in FIG. 1A.

In the figure, inside a boiler 1, a large number of water pipes 1b are installed along the inner circumferential surface of a wall 1a, and the water pipes 1b are made of a hollow cylindrical body, and the lower end thereof is an annular lower header 1c (water chamber). The upper end portions thereof communicate with the annular upper header 1d (steam chamber), and the lower portions of the lower header 1c and the water pipe 1b,
Canned water is stored.

A combustion chamber 1e is formed in the center of the boiler 1 surrounded by water pipes 1b, and an electric motor 1f is provided above the combustion chamber 1e.
An air passage 1h is provided which communicates with a blower 1g driven by a blower 1g, and a nozzle rod 1i and an electrode rod 1j are vertically provided within 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, a communication pipe 1l extends outside the wall 1a and communicates with the lower header 1c.

A water level gauge 1m and a water level detector 2 for visually displaying the canned water level are installed in the middle of the communication pipe 1l. A water supply control section 3 is connected to the water level detection section 2 , and an output terminal thereof is connected to an electric motor 4 a that drives a 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 pressure detection section 5 is connected to the upper part of the communication pipe 1l, and its output terminal is connected to a combustion control section 6. From the combustion control unit 6, control signal lines 6a to 6
c extends and is connected to each of the electric motor 1f, electrode rod 1j, and fuel pump 6d. An inlet pipe of the fuel pump 6d communicates with a fuel tank (not shown), and a discharge pipe thereof communicates with the nozzle rod 1i. A blow pipe 1n extends from the lower header 1c and communicates with a drainage channel (not shown) via a blower stock 1p, and a steam pipe 1q extends from the upper header 1d and communicates with a desired steam load (not shown).

In the configuration of the boiler system described above, when generating steam, the electric motor 1f drives the blower 1g to forcefully feed air into the air passage 1h while applying a high voltage to the electrode rod 1j to generate steam from the tip of the nozzle rod 1i. The injected fuel is ignited and combusted within the combustion chamber 1e. High-temperature combustion gas generated by such combustion enters the hollow part of the water pipe 1b from the lower end of the combustion chamber 1e, passes through it, reaches the flue 1k, and is exhausted. During this time, heat exchange takes place and the canned water in the water pipe 1b is heated and turned into steam, which is then transferred to the upper header 1d.
The steam is collected and stored at the steam pipe 1q and supplied to the steam load through the steam pipe 1q.

Regarding combustion control, the upper header 1d
The steam pressure in the upper header 1d is extracted through the communication pipe 1l and supplied to the pressure detector 5.
When the combustion control section detects that the vapor pressure within the combustion chamber has reached a preset lower limit vapor pressure, the lower limit vapor pressure signal is sent to the combustion control section. Send to 6.

When the combustion control unit 6 receives a lower limit steam pressure signal from the pressure detection unit 5 due to continued consumption of steam and the steam pressure in the upper header 1d falls, the combustion control unit 6 connects the control signal line 6 to the lower limit steam pressure signal from the pressure detection unit 5.
Start electric motor 1f through a, and blower 1g
After purging the air passage 1h with air, a high voltage is applied to the electrode rod 1j through the control signal line 6b, and at the same time, a high voltage is applied to the electrode rod 1j through the control signal line 6c.
starts, the fuel injected from the nozzle rod 1i is ignited to start combustion, and further, when steam generation continues and the steam pressure increases and an upper limit steam pressure signal is received from the pressure detection section 5, Combustion is stopped by stopping the fuel pump 6d and cutting off the fuel supply through the control signal line 6c, and after waiting for combustion gas to be discharged, the electric motor 1 is connected through the control signal line 6a.
Stop f and cut off the air from blower 1g.

Thus, even with intermittent control of combustion, the steam pressure in the upper header 1d can be maintained at a pressure value between the two pressure values preset as the upper and lower steam pressure limits.

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

Furthermore, regarding the water supply system, changes in the canned water level in the air-water interface in the communication pipe 1l, 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, a lower limit water level signal is sent to the water supply control unit 3, and similarly, when it is detected that the upper limit water level has been reached, an upper limit water level signal is sent to the water supply control unit 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 4a and causes the water supply pump 4 to lower the water pipe through the lower header 1c. 1
When the water supply to b is started, water supply continues, the can water level rises, 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.

Thus, even with the 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.

Also, when blowing canned water, use blowing stick 1.
By opening p, 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 1i,
The burner consisting of the electrode rod 1j is not limited to this, and if necessary, it is sufficient to heat the canned water in the water pipe 1b to generate steam, so generally an electric heater or the like is also used. Any heating device including the above may be used.

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

Next, the configuration and operation of an embodiment of the present invention will be described below based on FIGS. 2 to 4.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention.
WL is expressed by replacing the water level in the communication pipe 1l with the canned water level in the corresponding water pipe, and for the sake of simplicity, a hypothetical water pipe 1b' with a simple shape is shown as the water pipe. ing.

In addition, an expanded portion 1 formed at the bottom of the water pipe 1b'
c' is an equivalent representation of the lower header 1c in a hypothetical simple shape.

The water level detection unit 2 is a lower limit water level probe 2a (hereinafter referred to as a first water level probe) disposed such that its tip is located at the lower limit position L (hereinafter referred to as a first setting position) of canned water in intermittent control of water supply. ) and
Blow position B below the first setting position L (hereinafter referred to as
The blow water level probe 2b (hereinafter referred to as
(referred to as a second water level probe), an upper limit water level probe 2c disposed so that its tip is located at the upper limit position H of the can water, and an underwater electrode 2 buried in the can water.
d, an AC power source 2e whose one end is connected to the underwater electrode 2d, and the other end of the AC power source 2e and each of the first water level probe 2a, the second water level probe 2b, and the upper limit water level probe 2c. It consists of inserted current detectors 2f, 2g, and 2h.

The water supply control section 3 includes a flip-flop 3b, in which the output terminal of the current detector 2f is connected to its set terminal, and the output terminal of the current detector 2h is connected to its reset terminal through an inverter 3a, and a positive phase output of the flip-flop 3b. The terminal is driver 3c
and the other end is connected to the power supply 3.
d, and relay 3e connected to relay 3e.
The contact 3e' of e is the electric motor 4 that drives the water supply pump 4.
It is inserted into the power supply line 4b of a.

The blow speed detection unit 7 includes a monostable multivibrator 7a whose input terminal is connected to the output terminal of the current detector 2f, and a monostable multivibrator 7a whose input terminal is connected to the output terminal of the current detector 2f.
g, and a NAND gate 7c, one input terminal of which is connected to the positive phase output terminal of the monostable multivibrator 7a, and the other input terminal connected to the output terminal of the inverter 7b. Become.

The blow state detection unit 8 includes a monostable multivibrator 8b whose input terminal is connected to the water supply command switch 8a, and a monostable multivibrator 8c whose input terminal is connected to the positive phase output terminal of the monostable multivibrator 8b. , one input terminal is connected to the output terminal of the current detector 2g, and the other input terminal is connected to the positive phase output terminal of the monostable multivibrator 8b. A water supply command switch 8a' is inserted into the power supply line 4b of the electric motor 4a for driving the water supply pump 4.

Blow speed storage section 9 consists of a flip-flop 9a whose set terminal is connected to the output terminal of NAND gate 7c and whose reset terminal is connected to the complementary output terminal of monostable multivibrator 8c.

The intermittent blow detection section 10 has one input terminal connected to the positive phase output terminal of the flip-flop 9a,
It consists of a NAND gate 10a whose other input terminal is connected to the output terminal of AND gate 8d.

The input terminal of the display unit 11 is the NAND gate 1.
A counter 11a connected to the output terminal of 0a,
Drivers 11 sequentially following counter 11a
b, and a display tube 11c.

Figure 3 shows change A in can water level and current detector 2.
3 is a waveform diagram showing a comparison between output signals B and C of flip-flops h and 2f and a positive phase output signal D of a flip-flop 3b. FIG. First, the operation of water supply control with respect to the water level detection section 2 and water supply control section 3 in the above configuration will be explained as follows.

Now, as shown in Figure 3 Aa, if the can water level is higher than the first setting position L,
The first water level probe 2a is submerged in the can water, and conduction is established between the submersible electrode 2d through the can water, and the current detector 2f, the first water level probe 2a, and the submersible electrode 2d are connected to the AC power source 2e. Since a load circuit is formed, a current flows to the current detector 2f, which is detected by the current detector 2f as shown in Fig. 3.
Outputs "1" as shown in Cb.

Then, when the water level of the can water falls and reaches the first set position L as shown in FIG. is blocked, so
The current passing through the current detector 2f becomes zero, and upon detecting this, the current detector 2f outputs "0" as shown in FIG. 3 Cd.

Upon receiving the inversion of the output signal of the current detector 2f from "1" to "0" at the set terminal, the flip-flop 3b is set to "1", and its positive phase output signal is as shown in FIG. 3 De. is reversed from "0" to "1". Upon receiving this signal, the driver 3c becomes conductive, the relay 3e is energized, the contact 3e' is closed, and power is supplied to the electric motor 4a through the water supply command switch 8a', which is closed at this point. Therefore, canned water is supplied to the water pipe 1b'.

Thus, while the flip-flop 3b is at "1", the water supply continues and the can water level continues to rise as shown in FIG. 3Af.

Eventually, as shown in Fig. 3Ag, when the can water level reaches the upper limit position H, the upper limit water level probe 2c is submerged, and since it has been far from the water surface until now, as shown in Fig. 3Bh, As shown in Figure 3 Bi, the current detector 2h that was outputting "0"
It will now output "1".

The inversion of the output signal of the current detector 2h from ``0'' to ``1'' is converted by the inverter 3a into an inversion from ``1'' to ``0'' and supplied to the reset terminal of the flip-flop 3b. "0"
Reset to .

Therefore, as shown in FIG. 3Dj, the positive phase output signal of the flip-flop 3b becomes "0", so
Relay 3e becomes de-energized, contact 3e' opens, and water supply stops.

In this way, the water supply period T ₁ from when the water supply pump starts to when it stops is specified even during the period when the flip-flop 3b is set to "1", and furthermore, from when the water supply pump stops to when it starts. The water supply stop period _T2 is the flip-flop 3b.
It is specified even during a period in which the value is "0".

Therefore, after the water supply is stopped, as shown in Figure 3Ak, the canned water level drops again at a rate of decline that corresponds to the amount of evaporation, and this, as shown in Figure 3Al,
The flip-flop 3b remains at "0" until reaching the first setting position L, and then the third
As shown in Figure Dm, it is reversed to "1" and a water supply stop period _T2 is formed.

Thereafter, similar operations are repeated to maintain the can water level between the upper limit position H and the first set position L.

Next, referring to FIG. 4, the operation for detecting intermittent blowing during blowing work will be described as follows.

Figure 4 shows change A in can water level and current detector 2.
The output signals of f and 2g, that is, the first and second water level signals B and C, the positive phase output signal D of the monostable multivibrator 7a, the positive phase output signal E of the flip-flop 9a, and the positive phase output signal E of the monostable multivibrator 8b. FIG. 3 is a waveform diagram showing a comparison of a positive phase output signal F, an output signal G of an AND gate 8d, an output signal H of a NAND gate 10a, and a positive phase output signal I of a monostable multivibrator 8c.

When performing blowing work, the operator
p, and water supply command switches 8a, 8.
a' is opened and the water supply pump 4 is stopped by cutting off the power supply to the electric motor 4a regardless of the on/off operation of the relay contact 3e' in the water supply control unit 3.
Since the canned water in the water pipe 1b' is discharged at a large flow rate through the drain pipe 1n, the canned water level begins to fall rapidly, as shown in FIG. 4Aa.

Then, as shown in FIG. 4Ab, when the first water level probe 2a reaches the first setting position L, the first water level probe 2a leaves the water surface, so that the output signal of the current detector 2f changes as shown in FIG. 4Bc. The first water level signal S ₁ is output by inverting from "1" to "0", and in response to this inverted signal, the monostable multivibrator 7a is triggered as shown in FIG. transition to state.

During this period, the can water level was as shown in Figure 4 Ae.
Continuing the rapid decline, as shown in Figure 4 Af,
When the second set position B is reached, the second water level probe 2b leaves the water surface, so the output signal of the current detector 2g changes as shown in FIG. 4Cg.
The second water level signal S ₂ is reversed from “1” to “0”.
is output. This inverted signal is applied to the inverter 7b.
Since "0" is converted into an inverted signal to "1" by executed.

Therefore, as shown in FIG. 4Dh, during the quasi-stable period when the monostable multivibrator 7a is outputting "1", the output signal of the current detector 2g changes as shown in FIG. 4Cg. When "1" is inverted to "0", "1" is supplied to both input terminals of the NAND gate 7c, so the output signal of the NAND gate 7c is inverted from "1" to "0", and the blow speed signal S ₃
is output, and receiving this inverted signal at the set terminal, the flip-flop 9 is output as shown in Fig. 4 Ei.
a is set to "1".

The flip-flop 9a remains in the "1" state until it is reset and outputs the blow speed storage signal _S4 .

In this way, the blow speed detection unit 7 determines whether the can water level drops to the second set position B within a specific time preset as the metastable time of the monostable multivibrator 7a. As a result, the can water level drops to a position considerably below the second setting position B, that is, the lower limit position L in the intermittent control of water supply, which always appears during blowing work, and furthermore, the can water level decreases due to evaporation of the can water. detects that the can water level has fallen at a rate that is significantly faster than the rate of fall that is characteristic of blowing operations,
Outputs the blow speed signal _S3 and stores it in the blow speed storage section 9.
stores the blow speed signal _S3 and continuously outputs the blow speed storage signal _S4 .

Now, suppose that the canned water level is based on the amount of evaporation.
As shown in Fig. 4 Aa' and e', if we assume that the descent is at a slow speed, the point at which the second set position B is reached is shown in Fig. 4 Af', and until that point, As shown in FIG. 4Cg', the output signal of the current detector 2g remains at "1", so the flip-flop 9a is triggered during the metastable period of the monostable multivibrator 7a, as shown in FIG. 4Ei. Therefore, as shown in Figure 4 Ei',
The flip-flop 9a remains at "0" and the blow speed storage signal _S4 is not output.

Furthermore, as shown in Fig. 4 Aa'', if the canned water level rises again from the first setting position L, that is, the lower limit position in the intermittent water supply control after the intermittent water supply control is performed, the current detection The output signal of the device 2g does not invert to "0", and the second water level signal S ₂
Of course, the flip-flop 9a remains at "0" as well, since this cannot be obtained.

After performing intermittent blowing, the operator closes the blowing stock 1p, and then switches the water supply command switches 8a, 8.
When a' is closed, the power supply to the electric motor 4a for driving the water supply pump 4 is controlled by the opening and closing of the relay contact 3e', and the intermittent control operation of water supply is started.

At this point, regarding the intermittent control of water supply, since the can water level is far below the first setting position L, that is, the lower limit position, the above-mentioned intermittent control operation is performed, and the relay contact 3e' is closed and canned water supply to the boiler begins.

At the same time, the water supply command switch 8a is closed and the water supply command signal _S5 is given by grounding the input terminal of the monostable multivibrator 8b. 8b is triggered to enter a metastable state.

On the other hand, when water supply starts, in the case of intermittent blowing, as shown in Fig. 4 Ak, water supply starts from a state where the canned water level is not zero, that is, from a state where canned water remains. As shown in Al, the canned water level rises without part or all of the period required to fill the lower header 1c, and reaches the second set position B in a relatively short time. do.

Then, as shown in Figure 4 Am, the can water level reaches the second setting position B, and the output signal of the current detector 2g changes from "0" to "0" as shown in Figure 4 Cn. 1", the monostable multivibrator 8b is still in a quasi-stable state as shown in FIG. "but,
Then, "1" from the monostable multivibrator 8b is supplied to the other input terminal, and as shown in FIG. 4 Gp, the AND gate 8
The output signal of d is inverted from "0" to "1" and the blow state detection signal _S6 is output, and the NAND gate 10
"1" is supplied to one input terminal of a.

At this time, as described above, if the blow speed is detected and the blow speed storage signal _S4 is intermittently output from the flip-flop 9a, "1" is supplied to both input terminals of the NAND gate 10a. Therefore, the output signal of the NAND gate 10a is inverted from "1" to "0" as shown in FIG. 4 Hq, and the intermittent blow detection signal _S7 is output.

Subsequently, when the monostable multivibrator 8b returns to a stable state as shown in FIG. 4 Fr,
The monostable multivibrator 8c shifts to a quasi-stable state as shown in Fig. 4 Is, and upon receiving the inversion of its complementary output signal from "1" to "0" at the reset terminal, as shown in Fig. 4 Et. Like flipflop 9
a is reset to "0".

Then, as the monostable multivibrator 8b returns to the stable state, as shown in FIG. 4 Gu,
The output of the AND gate 8d changes from "1" to "0", the blow state detection signal _S6 disappears, and as a result,
As shown in FIG. 4 Hv, when the output of the NAND gate 10a is inverted from "0" to "1", the intermittent blow detection signal _S7 also disappears.

Now, let's assume that during boiler maintenance and inspection, water supply is started from a state where the can water level is zero, that is, from a state of complete blowing, as shown in Figure 4 Aw, rather than from intermittent blowing. Then, as shown in Figure 4 Al', the can water level rises at a slow rate according to the water supply flow rate.
In the initial stage of water supply, the lower header 1c, which has a wide cross-sectional area and is equivalently expressed as the expanded portion 1c' of the water pipe 1b', is filled with canned water, so the rate of rise is extremely slow, and the canned water level It takes a long time for the temperature to rise.

After the lower header 1c is filled with canned water, the water pipe 1b, which has a smaller cross-sectional area, is filled, so the canned water level rises at a relatively fast rate, as shown in Figure 4 Al''. do.

Then, the can water level is as shown in Figure 4 Am'.
When the second set position B is reached, the output signal of the current detector 2g is inverted from "0" to "1" and outputs the second water level signal _S2 , as shown in FIG. 4 Cn'.

However, in the case of water supply after complete blowing, it takes a long time to fill the lower header 1c, so the water supply command signal _S5 is not responded to when starting water supply before the can water level reaches the second set position B. The monostable multivibrator 8b, which had been in a quasi-stable state, returns to a stable state as shown in FIG. 4 Fr.

Therefore, in such a case, one input terminal of the AND gate 8d is supplied with "1" from the current detector 2g, but the monostable signal supplied to the other input terminal is Since the positive phase output signal of the multivibrator 8b is "0", the output signal of the AND gate 8d remains at "0", and the blow state detection signal _S6 is not output.

Since "0" continues to be supplied to one input terminal of the NAND gate 10a, the output signal of the NAND gate 10a is as shown in FIG. 4 Hx.
It remains at "1" and the intermittent blow detection signal _S7 is not output either.

In this way, the blow state detection unit 8 determines whether the can water level rises to the second set position B within a specific time preset as the metastable time of the monostable multivibrator 8b. When performing water supply work after intermittent blowing, the elapse of the water supply time for filling the canned water is detected, and the blowing state detection signal _S6 is output, and the intermittent blowing detection unit 10
The intermittent blow detection signal S ₇ is output based on the AND of the blow speed storage signal S ₄ from the blow speed storage section 9 and the blow state detection signal S ₆ .

When the intermittent blow detection signal _S7 is output, in response to this, the counter 11a counts the cumulative number of intermittent blows, and displays the display tube 11c through the driver 11b.
to visually display the cumulative number of intermittent blows.

The display section 11 may be configured to display the intermittent blow detection signal _S7 as information indicating the execution of the intermittent blow, or alternatively, the display tube 11c may be replaced with an output signal processing device and a type. A configuration may also be adopted in which a writer is attached and the date and time of the execution is printed in a tabular form along with the cumulative number of times the intermittent blowing is executed.

Furthermore, an arithmetic processing unit is attached to calculate the cumulative evaporation amount starting from the output point of the intermittent blow detection signal _S7 , and automatically control opening/closing of the blowing tank 1p, opening/closing of the water supply command switches 8a, 8a', etc. You can also use it as

In the above embodiment, the surface of canned water is detected using the conductivity between the first and second water level probes 2a2b and the underwater electrode 2d, but this is not limited to this. Since it is sufficient to detect the boundary surface of steam, the first and second water level probes 2a2b
In place of the above configuration, an optical water level sensor is provided in which a light emitting element and a light receiving element are disposed facing each other at first and second set positions, and a magnetic float is disposed at the first and second set positions. Optionally, the first and second water level sensors may include a magnetic water level sensor that detects the water level using a magnetic sensor. Alternatively, obtain a water pressure signal proportional to the can water level from a single pressure sensor,
A comparator may be used to detect that this signal has reached a value corresponding to the first and second set positions.

As in the above configuration, the first and second water level sensors can be integrated with a single piece of hardware, so the first and second water level sensors referred to in this specification are not necessarily separate. The present invention is not limited to a configuration implemented as independent hardware.

As described above, the present invention includes at least a blowing stock for controlling the blowing of canned water in a boiler;
In a boiler system equipped with a water supply pump that supplies canned water to the boiler in response to a water supply command signal, a first,
A second water level sensor is provided to form a water level detection unit, and when the canned water level reaches the first set position, a first water level signal is output, and the canned water level is lower than the first set position. When the second water level signal reaches the second setting position, a second water level signal is output, and a blow speed detection unit is provided to detect the blow speed based on the time difference between the first and second water level signals being less than or equal to a specific time. A blow speed storage unit is provided to detect the occurrence of a can water level drop rate specific to the work, a blow speed storage unit is provided to store the detection result, and a blow state detection unit is provided to detect the time difference between the water supply command signal and the second water level signal. The blowing state is detected based on the fact that is a water supply period specific to water supply work after intermittent blowing, and furthermore, an intermittent blow detection section is provided, and the can water level lowering speed peculiar to blowing work is stored in the blow speed storage section. What was detected is remembered, and
Since the blow state detection unit is configured to output an intermittent blow detection signal when detecting a blow state, execution of an intermittent blow can be distinguished from a complete blow and automatically detected. This makes it possible to automatically record historical data regarding blowing operations, such as recording and displaying the cumulative number of intermittent blowing operations.

Therefore, according to the present invention, historical data regarding the number and timing of intermittent blowing can be obtained without the troublesome work of recording each time in the driving log every time intermittent blowing is performed. There is no loss of historical data, and the timing of blowing operations can be accurately determined at any time, which has the excellent effect of preventing equipment damage caused by scale growth or carryover.

Furthermore, the first water level sensor in the configuration of the present invention can be used in common with the lower limit water level sensor that detects the lower limit water level for starting water supply during intermittent control of water supply essential to the boiler system, so the configuration is simple and wasteful. There is also the effect that it can be realized at low cost.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the configuration of the boiler system, Figures 2 to 4 are related to embodiments of the invention, Figure 2 is a block diagram showing the configuration, and Figure 3 is a block diagram showing the configuration.
4 are waveform diagrams of main parts. 2...Water level detection unit, 2a...First water level probe, 2b...Second water level probe, 3...Water supply control unit, 4...Water supply pump, 7...Blow speed detection unit, 8...Blow State detection section, 9... Blow speed storage section, 10... Intermittent blow detection section, 11... Display section.

Claims (1)

[Claims] 1. In a boiler system equipped with at least blowing means for controlling the discharge (blow) of canned water in the boiler and water supply means for supplying canned water to the boiler in response to a water supply command signal, the canned water level in the boiler a first water level sensor that detects that the water level in the boiler is present at a first set position and outputs a first water level signal; and a second set position where the can water level in the boiler is below the first set position. a second water level sensor that detects the presence of a water level signal and outputs a second water level signal; blow speed detection means for detecting a certain condition and outputting a blow speed signal; blow speed storage means for storing the blow speed signal and continuously outputting a blow speed storage signal; and a water supply command signal after blowing. blow state detection means that detects that the time difference with the second water level signal is less than a specific time and outputs a blow state detection signal; and a blow state detection means based on the AND of the blow speed storage signal and the blow state detection signal. An intermittent blow detection device for a boiler system, comprising an intermittent blow detection means for detecting execution of intermittent blow and outputting an intermittent blow detection signal.