JPH0221481B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a water level sensor check device for determining whether or not a water level sensor for detecting that the can water level has fallen below a specific value is functioning normally in a boiler system. In particular, the present invention relates to an improvement that makes it possible to easily check the function of a water level sensor even while the boiler is in operation.

Generally, in a boiler system, the supply of canned water to the water pipes is controlled intermittently to maintain the canned water level between the upper and lower limit water levels set specifically for the boiler system, and further below the control water level set below the lower limit water level. For the can water level of
The heating device is interlocked to prevent dry heating, and the water level sensor for this purpose is designed to interlock the water level sensor between the water level probe fixed at the water level to be detected and the underwater electrode buried in the water in the can. So-called electrode-type water level detection means, which uses a current detector to detect current based on the conductivity of water, is often used.

However, with such electrode-type water level detection means, if scale derived from impurities in the can water adheres to the water level probe, or if the current detector malfunctions, the correct can water level cannot be obtained.
There was a problem in that the boiler could no longer be operated at an appropriate can water level, leading to dry firing, and there was an extremely high risk of a burnout accident.

In particular, scale adhesion on the electrode type water level detection means occurs quite frequently, making the above problem even more serious.

In order to solve this problem, conventional equipment temporarily stops the operation of the boiler system and manually drains some of the canned water (intermittent blowing), thereby reducing the water level of the sensor that should be checked. The water level in the can was lowered to a certain level, and the state of the detection signal at this time was checked.

However, with such conventional devices, it is necessary to stop the operation of the boiler, even temporarily, which not only complicates operation and blowing operations, but also has the drawback of significantly reducing the operating efficiency of the boiler. However, the frequency of checking was considerably restricted, and it was difficult to prevent burnout accidents due to check leakage.

In view of the problem of the complexity of checking the water level sensor based on the above-mentioned conventional technology, it is an object of the present invention to make it possible to check the water level sensor frequently with a simple operation without stopping the operation of the boiler system. It is an object of the present invention to provide an excellent water level sensor check device for a boiler system that can reliably detect failures.

In accordance with the above object, the configuration of the present invention is such that the lower limit water level sensor check command signal unit checks the cumulative value of the heating period (hereinafter referred to as cumulative heating period), and when this reaches a preset first reference set value, the lower limit water level sensor check section checks the operation of the lower limit water level sensor by determining the presence or absence of a lower limit water level signal; Next, the control water level sensor check command signal section counts the cumulative heating period, and when this reaches a preset second reference set value, the control water level sensor check section also checks the presence or absence of the control water level signal. The operation of the control water level sensor is checked by determining the operation of the control water level sensor. The gist of this invention is to automatically time the time point at which a lower limit water level signal and a control water level signal should be obtained during normal operation, and to automatically determine the presence or absence of both signals.

An embodiment of the present invention will be described below based on FIGS. 1 to 4.

FIG. 1 is a block diagram showing the configuration of the above embodiment, in which a boiler A is surrounded by a side wall a, and a number of water pipes b are erected along the inner circumference of the boiler A, and the upper and lower parts of the water pipes b are annular. They are connected to form an upper header c and a lower header d, respectively.

Adjacent to the upper wall e of the boiler A are a blower g that is linked to a motor f, a fuel injection rod j that is connected to a fuel pipe i that communicates with a fuel tank (not shown) via a fuel valve h, and an electrode rod k. The combustion chamber m is surrounded by an air passage l communicating with the blower g.
A burner B having an opening is formed.

A communicating pipe n is extended between the upper and lower headers c and d, and a steam pressure detecting section 1 and a water level detecting section 3 are connected to the upper and lower parts of the communicating pipe n, respectively. A steam pipe o extends from the upper header c and is connected to a steam load (not shown).

A drain pipe p extends from the lower pipe header d to a drainage channel (not shown), and in the drain pipe p there is a block q.
is provided.

Furthermore, a water supply pipe u extends from the lower header d to a water source (not shown), and a pump w driven by an electric motor v is provided in the pipe u.

Note that x is a water level gauge connected to the communication pipe n.

The steam pressure detection unit 1 includes a pressure sensor 1a to which the steam pressure in the upper header c is guided through a communication pipe n.
, first and second comparators 1b and 1c whose respective first input terminals are connected to the output terminal of the pressure sensor 1a, and the first and second comparators 1
reference voltage sources 1d and 1e connected to the second input terminals of the reference voltage sources 1d and 1c, respectively.

The heating control section 2 includes a flip-flop 2b, in which the output terminal of the first comparator 1b is connected to its set terminal, and the output terminal of the second comparator 1c is connected to its reset terminal through an inverter 2a, and a positive-phase flip-flop 2b. It consists of a relay 2d whose output terminal is connected to one end through a driver 2c and the other end is connected to a power source, and connections 2d', 2d'', and 2d of the relay 2d control the electric motor f, electrode k, and fuel pump h. The control lines r, s, and t are inserted between the power supply and each of the control lines r, s, and t.

On the other hand, the water level detection section 3 includes a water supply control section 4, a water level sensor check circuit C, and an interlock circuit L.
The output terminal of the interlock circuit is connected to the reset terminal of the flip-flop 2b in the heating control section 2.

FIG. 2 is a block diagram showing the water level detection section 3, water supply control section 4, and water level sensor check circuit C.

Regarding the water level detection unit 3 in the same figure, in comparison with the configuration shown in FIG. The pipe n is a simple-shaped communicating pipe n that is directly supplied with water by the water supply pump W.
It is expressed in place of .

The water level detection unit 3 includes a lower limit water level probe 3 disposed such that its tip is located at the lower limit water level L of canned water.
a, an upper limit water level probe 3b disposed so that its tip is located at the upper limit water level H of canned water, and an upper limit water level probe 3b disposed so that its tip is located at a control water level C selected below the lower limit water level L. control water level probe 3g
, underwater electrode 3c buried in water, and underwater electrode 3
an AC power supply 3d with one end connected to c, a first current detector 3e inserted between the other end of the AC power supply 3d and the lower limit water level probe 3a, and the other end of the AC power supply 3d and the upper limit water level probe 3b. It consists of a second current detector 3f inserted between the two, and a third current detector 3h inserted between the other end of the AC power supply 3d and the control water level probe 3g.

In the water supply control unit 4, the positive phase output terminal of the first current detector 3e is connected to one of its set terminals, and the positive phase output terminal of the second current detector 3f is connected to its reset terminal through the inverter 4a. The flip-flop 4b is connected to one end of the flip-flop 4b, and the positive phase output terminal of the flip-flop 4b is connected to one end of the flip-flop 4b through a driver 4c, and the other end of the relay 4 is connected to a power supply.
The contact 4d' of the relay 4d is inserted into the power supply line y of the electric motor v that drives the water pump W.

Furthermore, one end of a set switch 4f inserted between the power supply and ground through a resistor 4e is connected to another set terminal of the flip-flop 4b.
connected via g. The set switch 4f has a contact 4 in the power supply line y of the motor v.
It is linked to the water supply control start switch z inserted in series with d'.

The check period signal section 5 has its set terminal connected to a set switch 5g inserted between the power supply and ground through a resistor 5f, and its reset terminal connected to a reset switch 5i inserted between the power supply and ground through a resistor 5h. a flip-flop 5a with one input terminal connected to the flip-flop 5a;
a, and the other input terminal is connected to the positive phase output terminal of the second current detector 3f in the water level detection section 2, and the output of the NAND gate 5b is connected to the set terminal of the NAND gate 5b. A flip-flop 5c has a reset terminal connected to the output terminal of a NAND gate 9a in the control water level sensor check section 9, and a positive phase output terminal of the flip-flop 5c is connected to one end of the flip-flop 5c through a driver 5d, and the other end is connected to the flip-flop 5c. The break contact 5e' of the relay 5e is inserted into the power supply line y of the electric motor v that drives the water pump W.

One input terminal of the lower limit water level sensor check command signal section 6 is connected to the positive phase output terminal of the flip-flop 5c, another input terminal is connected to the output terminal of the clock oscillator 8d, and the other input terminal is connected to the output terminal of the clock oscillator 8d. is an AND gate 6 connected to the positive phase output terminal of the flip-flop 2b in the heating control section 2.
a, a preset counter 6b whose input terminal is connected to the output terminal of an AND gate 6a, and a monostable multivibrator 6c following the preset counter 6b.

The lower limit water level sensor check section 7 has one input terminal connected to the first current detector 3 in the water level detection section 3.
It consists of a NAND gate 7a to which the complementary output terminal of the monostable multivibrator 6c is connected, and the positive phase output terminal of the monostable multivibrator 6c is connected to its other input terminal.

The control water level sensor check command signal section 8 has one input terminal connected to the positive phase output terminal of the flip-flop 5c, another input terminal connected to the output terminal of the clock oscillator 8d, and one input terminal connected to the output terminal of the clock oscillator 8d. is connected to the positive phase output terminal of the flip-flop 2b, a preset counter 8b whose input terminal is connected to the output terminal of the AND gate 8a, and whose input terminal is connected to the output terminal of the preset counter 8b. and a monostable multivibrator 8c.

The control water level sensor check section 9 has one input terminal connected to the complementary output terminal of the third current detection section 3h, and the other input terminal connected to the positive phase output terminal of the monostable multivibrator 8c. It consists of a NAND gate 9a.

The display section 10 includes a flip-flop 10a whose set terminal is connected to the output terminal of the NAND gate 7a, whose reset terminal is connected to the reset switch 5i, and a driver whose input terminal is connected to the positive phase output terminal of the flip-flop 10a. 1
0b, a lamp 10c following it, a flip-flop 10d whose set terminal is connected to the output terminal of the NAND gate 9a, and whose reset terminal is connected to the reset switch 5i, and whose input terminal is the positive phase output of the flip-flop 10d. It consists of a driver 10e connected to a terminal and a lamp 10f following it.

The check period signal section 5, lower limit water level sensor check command signal section 6, lower limit water level sensor check section 7, control water level sensor check command signal section 8, control water level sensor check section 9, and display section 10 are the water level sensor check circuit C. It forms the

FIG. 3 is a waveform diagram illustrating the waveforms of the main parts of the steam pressure detection section 1, heating control section 2, water level detection section 3, and water supply control section 4. ), the output signal of the first comparator 1b, or the positive phase output signal (B) of the first current detector 3e, and the output signal of the second comparator 1c,
Alternatively, the positive phase output signal of the second current detector 3f
(C) and the positive phase output signal (D) of flip-flop 2b or flip-flop 4b are shown in comparison.

Regarding the above configuration, first, the operations of normal heating control and water supply control will be explained as follows.

Now, the vapor pressure in water pipe b, that is, the vapor pressure in communication pipe n, decreases as steam is consumed (Fig. 3 (A) a),
When the lower limit vapor pressure P _L is reached (Fig. 3 (A) b), the vapor pressure signal S ₁ outputted by the pressure sensor 1a according to the vapor pressure corresponds to the lower limit vapor pressure supplied from the reference voltage source 1d. Since it is smaller than the lower limit set value V _L ,
The output signal of the first comparator 1b is inverted from "1" to "0" (Fig. 3 (B) c), and the lower limit vapor pressure signal is
_{S_PL} is supplied to the set terminal of flip-flop 2b. Then, the flip-flop 2b is set (FIG. 3(D)d), the relay 2d is placed in an excited state, and the contacts 2d', 2d'', and 2d are closed.

Then, the blower g starts blowing air, the fuel valve h opens and supplies fuel to the agricultural jetting rod j, and the electrode rod k starts spark discharge, so the burner B shifts to the ignition state. do.

In the ignited state, the vapor pressure increases (Fig. 3(A)e),
Eventually, when the upper limit vapor pressure P _H is reached (Fig. 3 (A)
f), this time, the vapor pressure signal S ₁ is the upper limit setting value corresponding to the upper limit vapor pressure supplied from the reference power source 1e.
Since it is larger than V _H , the second comparator 1
The output signal of c is inverted from "0" to "1" (Fig. 3(C)g), and the upper limit vapor pressure signal _SPH is output.

This inverted signal from "0" to "1" is converted into an inverted signal from "1" to "0" by the inverter 2a, and is supplied to the reset terminal of the flip-flop 2b to reset it (FIG. 3). (D)
h).

Then, relay 2d shifts to the de-energized state and contacts 2d', 2d'', 2d open, so burner B
transitions to a non-ignition state.

In the non-ignition state, the vapor pressure decreases (Fig. 3 (A)
i), when the lower limit vapor pressure P _L is eventually reached (the third
(A)b'), the first comparator 1b operates in the same manner as before (FIG. 3(B)c'), the flip-flop 2b is set again (FIG. 3(D)d'), and the burner B is turned on. Transition to ignition state again.

In this way, the intermittent control of burner B is repeatedly performed, and the steam pressure in the upper header c reaches the upper and lower limit steam pressures.
The pressure is maintained between P _H and P _L.

A period T1 during which the flip-flop 2b is set to " ₁ " represents a heating period, and a period _T2 during which the flip-flop 2b is set to "0" represents a heating stop period.

In exactly the same way, if the rise and fall of the detected can water level in the water level detection unit 3 is assumed to be as shown in Fig. 3 (A), when the can water level reaches the lower limit water level L (Fig. 3 (A) b), the lower limit water level probe 3a, which had been submerged up to this point, leaves the water surface, so the AC power supply 3
A load circuit consisting of a first current detector 3e, a lower limit water level probe 3a, and an underwater electrode 3c connected to d is cut off between the probe 3a and the electrode 3c, and up to this point, The current passing through the detector 3e is cut off.

Then, the output signal of the detector 3e is inverted from "1" to "0", outputs the lower limit water level signal S _L (FIG. 3(B)c), and sets the flip-flop 4b (FIG. 3(B)). D) Because of d), the relay 4d shifts to the energized state, the contact 4d' closes, and the water supply pump W is started, thereby supplying water to the water pipe b, that is, the communication pipe n'. .

When the can water level rising due to water supply reaches the upper limit water level H, the upper limit water level probe 3b, which had been away from the water surface up to this point, is submerged in water, so that conduction occurs between the probe 3b and the underwater electrode 3c, and the second Current begins to pass through the current detector 3f.

Then, the output signal of the current detector 3f becomes "0".
is reversed to "1", outputs the upper limit water level signal S _H (Fig. 3 (C) g), and resets the flip-flop 4b (Fig. 3 (D) h), so that the relay 4d becomes de-energized. The water supply pump W stops.

When the water supply stops, the water level in the can drops (see Figure 3).
(A)i), and eventually reaches the lower limit water level L (Fig. 3 (A)
b'), the first current detector 3e operates in the same manner as described above (FIG. 3(B)c'), the flip-flop 4b is set again (FIG. 3(D)d'), and water supply begins.

Thus, the intermittent control of the water supply pump W is performed separately and independently from the intermittent control of the burner B, and the can water level is maintained at a level between the upper and lower limit water levels H and L.

A period t1 during which the flip-flop 4b is set to " ₁ " represents a water supply period, and a period _t2 during which the flip-flop 4b is set to "0" represents a water supply stop period.

Next, the operation of the water level sensor check circuit C is as follows.
The explanation will be as follows with reference to FIG. 4 as well.

FIG. 4 shows the water level detection section 3, check period signal section 5, heating control section 2, lower limit water level sensor check command signal section 6, lower limit water level sensor check section 7, control water level sensor check command signal section 8, and control water level sensor. 3 is a waveform diagram illustrating main part waveforms of the check section 9. FIG.

Now, when checking the water level sensor,
When the set switch 5g is manually closed during boiler operation, the check command signal Ss is reversed from "1" to "0", the flip-flop 5a is set, and the flip-flop is connected to one input terminal of the following NAND gate 5b. 5a is supplied with a positive phase output signal "1" (FIG. 4(B)a).

Under such operating conditions, when the can water level reaches the upper limit water level H (FIG. 4(A)b), the first current detector 3e in the water level detector 3 outputs "1" as the upper limit water level signal S _H. is supplied to the other input terminal of the NAND gate 5a, so the gate 5a receives "1" at both input terminals and its output signal is inverted to "0".

Then, the subsequent flip-flop 5c is set (Fig. 4(C)c), and its positive phase output signal excites the relay 5e via the driver 5d as the continuous check period signal _S2 (Fig. 4(C)d). Then, the break contact 5e' opens to stop the water pump W.

The check period signal _S2 is also simultaneously supplied to one input terminal of an AND gate 6a in the lower limit water level sensor check command signal section 6, and an opportunity to output "1" to the gate 6a, in other words, a clock oscillator 8d. This provides an opportunity to pass the clock pulses from the preset counter 6b to the subsequent preset counter 6b.

Since the heating period signal _ST is supplied from the heating control unit 2 to the other input terminal of the gate 6a, the gate 6a is in the above operating state.
Under the control of the signal S _T , only during the heating period T ₁
Intermittent clock pulse preset counter 6
b, and counted (Fig. 4(E)e).

When the preset counter 6b completes counting a preset number of clock pulses, it becomes "1",
It supplies an output signal in which the "0" state is inverted.

By the way, at the time of Figure 4 (A) b, the water supply suspension period
After the start of t ₂ , the can water level decreased (Fig. 4).
(A) f), the time required to reach the lower limit water level L (Fig. 4 (A) g) is a value specific to the boiler system,
Once the steam load is determined, it will be specified accordingly.

However, when considered in more detail, the fact that the canned water level falls from the upper limit water level H to the lower limit water level L means that a specific amount of canned water stored in the part of the water pipe narrowed between the upper and lower water limits evaporates. This means that the canned water is carried away outside the water pipe as a steam load, but from a macroscopic perspective, the above specified amount of canned water is converted into steam by the amount of heat added to the water pipe during each heating period _T1 . Since it is also the cumulative value of the amount of canned water to be converted, even if the steam load changes, when the cumulative heating period ΣT ₁ reaches a specific value specific to the boiler system, the specified amount of canned water will be transferred to the water pipe. It can be seen that the can water level drops from the upper limit water level H to the lower limit water level L.

Therefore, the rate of fall of the can water level (Fig. 4 (A) f), in other words, the time required for the can water level to drop from the upper limit water level H to the lower limit water level L is related to the cumulative heating period ΣT ₁ . (Figure 4(D) h).

Such cumulative heating period ΣT ₁ is determined by actual measurement, and is preset in the preset counter 6b as a first reference set value.

When checking the water level sensor, after the flip-flop 5c is set (FIG. 4(C)c, d), a clock pulse (fourth clock pulse) is intermittently supplied to the preset counter 6b every heating period _T1 . (E) e) is cumulatively counted by the counter 6b, and the cumulative value increases to the first reference setting value.

Then, the counter 6b outputs an inverted signal and returns to the reset state, and upon receiving the inverted signal, the following monostable multivibrator 6c shifts to a quasi-stable state (FIG. 4(F)i), and its correct Phase output signal “1” is lower limit water level sensor check command signal S ₃
The signal is supplied to one input terminal of the NAND gate 7a in the lower limit water level sensor check section 7.

However, as described above, the time it takes for the content of the preset counter 6b to reach the first reference set value is related to the rate of decline of the water level in the can, so during the metastable period of the multivibrator 6c. (Fig. 4 (F) j), the can water level drops to the lower limit water level L (Fig. 4 (A) g), and at this time, the lower limit water level probe 3a and the first current detector 3e If the operation is normal, the positive phase output signal of the detector 3e is inverted from "1" to "0" (Fig. 4(G)k), and at the same time, its complementary phase output signal is inverted from "0" to "0". 1'' and is supplied to the other input terminal of the NAND gate 7a as the lower limit water level signal S _L '.

Then, "1" is supplied to the two input terminals of the NAND gate 7a, so the gate 7a
outputs "0" as the lower limit water level determination signal _S4 (FIG. 4(H)l), and sets the flip-flop 10a in the display section 10 (FIG. 4(I)m).

Eventually, the monostable multivibrator 6c returns to a stable state, and the output signal of the gate 7a also becomes "1".
However, the flip-flop 10a remains at "1" until it is reset by receiving the reset signal S _R from the manually operated reset switch 5i.

During this time, the driver 10e becomes conductive and the lamp 10c lights up, indicating that the lower limit water level probe 3a and the first current detector 3e are operating normally.

On the other hand, in the check operation of such a water level sensor,
Since the flip-flop 5c stores "1" (Fig. 4(C) d') and the break contact 5e' is kept open, even if the can water level drops to the lower limit water level L (the In Fig. 4 (A) g), water supply is not started and the can water level continues to fall (Fig. 4 (A) p), and eventually falls to the control water level C (Fig. 4 (A) q). ),
During this time, a check operation is performed on the water level sensor related to the control water level probe 3g and the third current detector 3h.

In other words, the clock pulse from the clock oscillator 8d passes through the AND gate 8a to control the heating period.
For every T ₁ , it is intermittently supplied to the preset counter 8b (Fig. 4 (J)r) and counted, and the contents of the counter 8b are set from the same viewpoint as the first reference set value. When the second reference setting value is reached, the following unit constant multivibrator 8c shifts to a quasi-stable state ((K)s in Fig. 4), and "1" as the control water level sensor check command signal _S5 indicates the control water level. "1" as the control water level sensor check command signal _S5 , which is supplied to one input terminal of the NAND gate 9a in the sensor check section 9 (FIG. 4(K)s), is supplied to one input terminal of the NAND gate 9a in the control water level sensor check section 9. 9a (FIG. 4(K)t).

During the metastable period of the multivibrator 8c (Fig. 4 (K) t), when the can water level drops to the control water level C (Fig. 4 (A) q), the third current detector 3h is activated. The positive phase output signal is inverted to “0” (fourth
(L)u), at that time, the control water level signal Sc' obtained from the complementary output terminal of the detector 3h is "1".
is supplied to the other input terminal of the NAND gate 9a, so the gate 9a receives "1" at both input terminals, and the control water level determination signal S ₆
"0" is output (FIG. 4 (M) v).

Then, the subsequent flip-flop 10d is set to "1" (Fig. 4 (N)w), the lamp 10f is turned on via the driver 10e, and the control water level probe 3g and third current detector 3h operate normally. .

The inverted signal of the NAND gate 9a to "0" is also supplied to the reset terminal of the flip-flop 5c and resets it to "0" (FIG. 4(C)x), so that the break contact 5e' closes again. Then, the water supply is controlled intermittently, and the canned water level starts to rise again (Fig. 4 (A) y).

Eventually, when the metastable period of the monostable multivibrator 8c ends, the multivibrator 8c
is inverted to "0", and the output signal of the NAND gate 9a is inverted to "1" (FIG. 4(M)z).

The above operation description is for the case where the operation of the water level sensor is normal, but if the operation of the lower limit water level probe 3a and the first current detector 3e is not normal, during the metastable period of the monostable multivibrator 6c. (Fig. 4(C)i), the output signal from the first current detector 3e is not inverted, and the lower limit water level signal S _L ' cannot be obtained (Fig. 4(G)k'). The output signal remains at "1", and the lower limit water level judgment signal S4 is not obtained (Fig. ₄ (H) l'), so the flip-flop 10a is not set (Fig. 4 (I) m'). , the lamp 10c is not lit.

Furthermore, if the operation of the control water level probe 3g and the third current detector 3h is not normal, during the metastable period of the monostable multivibrator 8c (Fig. 4 (K)
t), the output signal from the third current detector 3h is not inverted and the control water level signal Sc' is not obtained (Fig. 4(L)u'), so the output signal of the NAND gate 9a is "1".
, and the control water level judgment signal _S6 was not obtained (4th
(M)v′), and the flip-flop 10d
is not set (Fig. 4 (N) w'), and lamp 10
F doesn't even light up.

In addition, when the can water level drops to the control water level, the control water level signal Sc obtained from the third current detector 3h is supplied to the interlock circuit L shown in FIG. As long as Sc exists, flip-flop 2 in heating control section 2
By holding the reset terminal of flip-flop 2b at "0", flip-flop 2b is locked at "0".

Therefore, when the can water level falls below the control water level C, the operation of the heating device is automatically prohibited, thereby preventing burnout of the boiler.

As described above, according to the present invention, there is provided a water supply control section that intermittently controls water supply to a water pipe based on upper and lower limit water level signals from a water level detection section including an upper and lower limit water level sensor, and an upper and lower limit water level signal from a vapor pressure detection section. A check operation as a check period in a boiler system equipped with a heating control unit that intermittently controls a heating device based on a steam pressure signal, and a control water level sensor that outputs a control water level signal to interlock the heating device. During the first water supply stop period after the start, the heating period in the heating control unit is counted to calculate the cumulative heating period, and when this reaches the preset first reference setting value, the lower limit water level signal is The presence or absence of the control water level signal is determined, and the normality of the operation of the lower limit water level sensor is checked, and furthermore, the presence or absence of the control water level signal is determined at the time when the cumulative heating period reaches a preset second reference set value. By configuring the system to check the normality of the operation of the control water level sensor, the water level sensor can be automatically checked with an extremely simple operation, and there is no need to stop the boiler operation when checking. Since there is no loss of heat energy due to shutdown, it is possible to eliminate restrictions on the frequency of checks. Frequent checks prevent check leaks and, in turn, effectively prevent boiler burnout. It has the excellent effect of preventing

Further, according to the present invention, the cumulative value of the heating period represented by the heating period signal ST from the heating control section 2 is set in advance in the lower limit water level sensor check command signal means 6 to the control water level sensor check command signal means 8. By detecting that the first and second reference values have been reached, when measuring the cumulative value ΣT1 of the heating period, at the same time the starting point of the period in which the can water level should be determined, that is, the lower limit water level is detected. By adopting a configuration in which a real time measurement operation of the elapsed time is performed to specify the generation point of the sensor check command signal S3 to the control water level sensor check command signal S5, the time measurement function of the cumulative value of the heating period and the canned water Since the timekeeping function for specifying the time period for determining the water level is secured in each configuration, the timekeeping function for specifying the period for determining the canned water level, etc. is ensured, as was the case with many conventional technologies. There is no need to provide a separate timer just for this purpose, and the configuration can be simplified accordingly.

[Brief explanation of drawings]

1 to 4 relate to an embodiment of the present invention, and FIG. 1 is a block diagram showing its configuration;
Figure 2 is a block diagram showing the water level detection section, water supply control section, and water level sensor check circuit;
4 and 4 are waveform diagrams of main parts. 1... Steam pressure detection section, 2... Heating control section, 3...
... Water level detection section, 4 ... Water supply control section, 5 ... Check period signal section, 6 ... Lower limit water level sensor check command signal section, 7 ... Lower limit water level sensor check section, 8
...Control water level sensor check command signal section, 9...
Control water level sensor check section, 10...display section.

Claims (1)

[Claims] 1. A lower limit sensor 3a that detects that the canned water level is at the lower limit water level and outputs lower limit water level signals SL, SL';
3e, and upper limit water level sensors 3b and 3f that detect that the can water level is an upper limit water level above the lower limit water level and output an upper limit water level signal SH; and a lower limit water level signal SL. An intermittent control water supply control means 4 that starts the water supply pump W that supplies water to the water pipes in response and stops the water supply pump W in response to the upper limit water level signal SH; and a steam pressure signal S1 that corresponds to the steam pressure of the boiler. a first comparator 1b that detects that the vapor pressure signal S1 is the lower limit setting value corresponding to the lower limit vapor pressure and outputs the lower limit vapor pressure signal SPL; A vapor pressure detection means 1 comprising a second comparator 1c which detects that the upper limit setting value corresponds to an upper limit vapor pressure that is greater than the vapor pressure and outputs an upper limit vapor pressure signal SPH; and a lower limit vapor pressure signal SPL. In response to the upper steam pressure signal, the heating device is started to heat the boiler.
In a boiler system equipped with an intermittent control heating control means 2 that stops the heating device in response to SPH, in response to a check command signal Ss, the first water supply stop period after receiving the check command signal Ss is determined. A check period signal means 5 for outputting a check period signal S2 that continues for a predetermined duration from the start point.
Based on the check period signal S2 and the heating period signal ST from the heating control means 2, it is detected that the cumulative value of the heating period during the check period has reached a preset first reference setting value. a lower limit water level sensor check command signal means 6 that outputs a lower limit water level sensor check command signal S3 that continues for a predetermined duration; a lower limit water level sensor check command signal S3 and a lower limit water level signal SL from the lower limit water level sensors 3a and 3e; ′, the lower limit water level sensor check command signal S
The lower limit water level determination signal S is determined by determining whether the can water level has reached the lower limit water level during the predetermined duration period of step 3.
A water level sensor checking device in a boiler system, comprising: a lower limit water level sensor checking means 7 for outputting a water level of 4; 2. A lower limit sensor 3a that detects that the canned water level is at the lower limit water level and outputs lower limit water level signals SL, SL';
3e, upper limit water level sensors 3b and 3f that detect that the canned water level is an upper limit water level above the lower limit water level and output an upper limit water level signal SH, and a control water level where the canned water level is selected to be lower than the lower limit water level. Water level detection means 3 consisting of control water level sensors 3g and 3h that output a control water level signal Sc when detecting that
and an intermittent control water supply control means 4 that starts the water supply pump W that supplies water to the water pipes in response to the lower limit water level signal SL and stops the water supply pump W in response to the upper limit water level signal SH; a pressure sensor 1a that outputs a vapor pressure signal S1 corresponding to the lower limit vapor pressure, and a first comparator 1b that detects that the vapor pressure signal S1 is a lower limit set value corresponding to the lower limit vapor pressure and outputs a lower limit vapor pressure signal SPL. , a second comparator 1c that detects that the vapor pressure signal S1 is an upper limit setting value corresponding to an upper limit vapor pressure that is larger than the lower limit vapor pressure, and outputs an upper limit vapor pressure signal SPH. and, in response to the lower limit steam pressure signal SPL, starts the heating device for heating the boiler, and responds to the upper limit steam pressure signal SPL.
In a boiler system equipped with an intermittent control heating control means 2 that stops the heating device in response to SPH, in response to a check command signal Ss, the first water supply stop period after receiving the check command signal Ss is determined. A check period signal means 5 for outputting a check period signal S2 that continues for a predetermined duration from the start point.
Based on the check period signal S2 and the heating period signal ST from the heating control means 2, it is detected that the cumulative value of the heating period during the check period has reached a preset second reference set value. and a control water level sensor check command signal means 8 that outputs a control water level sensor check command signal S5 that continues for a predetermined duration; the control water level sensor check command signal S5 and the control water level signals from the control water level sensors 3g and 3h; Based on the control water level sensor check command signal S
The control water level determination signal S is determined by determining whether or not the can water level has reached the control water level during the predetermined duration period of step 5.
6. A water level sensor checking device in a boiler system, comprising: a control water level sensor checking means 9 outputting a signal 6; 3 lower limit sensor 3a, which detects that the can water level is at the lower limit water level and outputs lower limit water level signals SL, SL';
3e, upper limit water level sensors 3b and 3f that detect that the canned water level is an upper limit water level above the lower limit water level and output an upper limit water level signal SH, and a control water level where the canned water level is selected to be lower than the lower limit water level. Water level detection means 3 consisting of control water level sensors 3g and 3h that output a control water level signal Sc' when detecting that
and an intermittent control water supply control means 4 that starts the water supply pump W that supplies water to the water pipes in response to the lower limit water level signal SL and stops the water supply pump W in response to the upper limit water level signal SH; a pressure sensor 1a that outputs a vapor pressure signal S1 corresponding to the lower limit vapor pressure, and a first comparator 1b that detects that the vapor pressure signal S1 is a lower limit set value corresponding to the lower limit vapor pressure and outputs a lower limit vapor pressure signal SPL. , a second comparator 1c that detects that the vapor pressure signal S1 is an upper limit setting value corresponding to an upper limit vapor pressure that is larger than the lower limit vapor pressure, and outputs an upper limit vapor pressure signal SPH. and, in response to the lower limit steam pressure signal SPL, starts the heating device for heating the boiler, and responds to the upper limit steam pressure signal SPL.
In a boiler system equipped with an intermittent control heating control means 2 that stops the heating device in response to SPH, in response to a check command signal Ss, during the first water supply stop period after receiving the command signal, A check period signal means 5 for outputting a check period signal S2 that continues for a predetermined duration from the start point.
Based on the check period signal S2 and the heating period signal ST from the heating control means 2, it is detected that the cumulative value of the heating period during the check period has reached a preset first reference setting value. a lower limit water level sensor check command signal means 6 that outputs a lower limit water level sensor check command signal S3 that continues for a predetermined duration; a lower limit water level sensor check command signal S3 and lower limit water level signals from the lower limit water level sensors 3a and 3e; Based on SL', the lower limit water level sensor check command signal S
The lower limit water level determination signal S is determined by determining whether the can water level has reached the lower limit water level during the predetermined duration period of step 3.
a lower limit water level sensor check means 7 which outputs a lower limit water level sensor of 4; a control water level sensor check command signal means 8 which detects that the reference set value of has been reached and outputs a control water level sensor check command signal S5 that continues for a predetermined duration; a control water level sensor check command signal S5; Based on the control water level signals Sc' from the water level sensors 3g and 3h, the control water level sensor check command signal S
The control water level determination signal S is determined by determining whether the can water level has reached the control water level during the predetermined duration period of step 5.
A water level sensor checking device in a boiler system, comprising: a control water level sensor checking means 9 that outputs a signal 6;