JPS5921903A - Measuring device for state of adhesion of scale 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 scale adhesion state measuring device for automatically measuring the scale adhesion state in water pipes due to the concentration of canned water in a boiler system. This invention relates to a scale adhesion state measuring device that measures the scale adhesion state in water pipes based on the phenomenon that the rise period of steam pressure at startup increases as scale adhesion progresses in the water pipes. .

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, it is known that scale adhesion reduces the efficiency of heat exchange in the boiler system, causes water pipes to reach high temperatures, and eventually causes burnout. There is.

Therefore, in order to deal with this inconvenience, it is necessary to check the state of scale adhesion in the water pipes by regular visual observation, and when scale adhesion has progressed to a certain extent, the scale should be dissolved and removed by passing medicine through the water pipes. One thing is being done.

However, in order to visually observe the state of scale adhesion, it is necessary to stop the operation of the boiler system, blow out canned water, and then observe the inside of the water pipes, which is a time-consuming process. Ta.

Therefore, such work is often neglected, and as a result,
Often, the abnormal growth of scale was overlooked and the water pipes were eventually burned out, requiring a great deal of time and effort to restore them.

In addition, since the work involves stopping the operation of the boiler system, the visual observation of scale adhesion is subject to significant restrictions on its frequency, resulting in a long sampling period for measurement, leading to delays.

Therefore, with conventional boiler systems, it is not possible to automatically and highly accurately and continuously measure the state of scale adhesion in water pipes, and it is therefore difficult to accurately determine when scale should be removed. unable to do so, allowing abnormal growth in scale,
The drawback was that there was an extremely high risk of burning out the water pipes.

In view of the problems of measuring the state of scale adhesion in water pipes based on the above-mentioned conventional technology, it is an object of the present invention to provide a vapor pressure measuring means and a means for measuring the vapor pressure rise period until the vapor pressure signal reaches a set value for measurement. vapor pressure rise period measuring means,
By configuring the scale adhesion state determining means for determining the scale adhesion state based on the vapor pressure rise period measurement signal of the means, the above-mentioned drawbacks are eliminated.
It is an object of the present invention to provide a scale adhesion state measuring device in a boiler system that can automatically measure the scale adhesion state virtually continuously with high precision and with a short measurement sampling period every time the operation is restarted. It is something to do.

The configuration of the present invention in accordance with the above object detects that a steam pressure signal corresponding to the steam pressure of the boiler is a measurement setting value, outputs a measured steam pressure signal, and outputs a measured steam pressure signal based on the signal and a start command signal. , measure the steam pressure rise period from the initial value at startup until the vapor pressure signal reaches the measurement set value, and determine the magnitude relationship between the measured vapor pressure rise period signal and a preset reference signal. The gist of the present invention is to determine the scale adhesion state based on the scale adhesion state, supply a scale adhesion state signal to the display section, and display that the scale adhesion state has been reached.

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. 1FA) 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(13) 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 the water pipes 1b are made of a hollow cylindrical body, and the lower end thereof is an annular lower header 1c (ice chamber).
And, on top of that, G! The Ij section communicates with the upper header ld (steam chamber), which is also a block, and the lower header 1C.
Canned water is stored in the lower part of the water pipe 11).

A combustion chamber 1e is located in the center of the boiler 1 surrounded by water pipes 1b.
formed from. An air passage 1b 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 1'' are vertically provided in the air passage 1h.

The lower end of the combustion chamber 1e communicates with the flue 1k through the hollow parts of a number of water pipes 1b. From the upper header, a communicating pipe 11 extends outside the wall 1a and connects to the lower pipe Mj and 1C. communicate.

A water level gauge 1 m and a water level detection unit 2 are installed in the middle of the communication pipe 11 to visually display the water level of the canned water. 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 . A water supply pipe of the water supply pump 4 communicates with a water source (not shown), and its discharge pipe 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 section 6 and are connected to the electric motor 1f, the electrode rod 1j, and the fuel pump 6d', respectively. A two-piece inlet pipe of the fuel pump 6d' communicates with a fuel tank (not shown), and its discharge pipe communicates with the nozzle rod 11. A blow pipe 1 [1 extends from the lower header 1C and communicates with a drainage channel (not shown) via a blow cock 1p, and a steam pipe 1q extends from the upper header 1d to meet a desired steam load (not shown). Communicate.

In the configuration of the boiler system described above, when generating steam, the blower 1g is driven by the electric motor 1f to forcefully feed air into the air passage 1h, and a high voltage is applied 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. 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 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 combustion control, the steam pressure in the lower 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 air has dropped and a lower limit vapor pressure signal is received from the vapor pressure measuring section 5, the electric motor 1f is started through the control signal line 6a', and the blower 1g is used to blow air through the air passage 1h. Then, connect the electric wire rod 1j through the control signal line 6b'.
At the same time, a high voltage is applied to the fuel pump 6 (1') through the control signal line 60' to ignite the fuel injected from the nozzle rod 11 and start combustion. When the vapor pressure increases and an upper limit vapor pressure signal is received from the vapor pressure measuring section 5, the fuel pump 6d' is stopped via the control signal line 60' to cut off the fuel supply, thereby stopping combustion and After waiting for the gas to be discharged, the electric motor 1f is stopped via the control signal line 6a' and the air blowing from the blower 1g is cut off.

Thus, by intermittent control of combustion, it is possible to maintain the steam pressure in the upper header 1d at a pressure value between side pressure values preset as upper and lower steam pressure limits.

In addition, simple devices include electric i1f, 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 can water level in the water pipe drops due to steam consumption and a lower limit water level signal is received from the water level detector 2, the water supply control unit 3 starts the electric motor 4a and uses the water supply pump 4 to pump water through the lower pipe header 1C. Water supply to the persimmon water pipe is started, water supply continues, the can water level rises, and when an upper limit water level signal is received from the water level detection part 2, the electric motor 414a is stopped to cut off the water supply to the water pipe 1b.

By controlling the water supply on and off, the water level of the canned water in the water pipe 1b can be maintained at a level between the upper and lower limit water levels, which are set in advance.

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 blower 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 configuration and operation of the embodiment of the present invention will be explained based on FIGS. 2 and 3 as follows.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, and in the figure, components denoted by the same reference numerals as those in FIG. 1 correspond to those in FIG. 1, respectively.

The steam pressure measurement unit 5 includes a pressure sensor 5a that receives steam pressure from the boiler and outputs a steam pressure signal S1, and subsequent first, second, and third controllers, e-lators 5b, 5c, and 5d. , first, second, third potentiometers 5e, 5f, 5
It consists of g.

As mentioned above, when the vapor pressure reaches the upper limit vapor pressure, the vapor pressure signal S1 corresponding to the vapor pressure becomes larger than the reference signal representing the upper limit setting value set by the first potentiometer 5e. The output signal of the first comparator 5b is “
0'', and the comparator 5b outputs an upper limit vapor pressure signal S2, which is supplied to the combustion control section 6.

Similarly, when the vapor pressure reaches the lower limit vapor pressure, the output signal of the second comparator 5C is inverted to "0" and the lower limit vapor pressure signal S3 is output.

The other input terminal of the third comparator 5d is connected to a power source via a third potentiometer 5g that sets a measurement setting value.

The output terminal of the third comparator 5d is connected to the vapor pressure rise period measuring section I. The measuring section γ consists of a clock pulse exciter, a gate, and a time interval counting circuit including a counter.

On the other hand, the output terminal of the start switch 8 is connected to the water supply control section 3,
It is connected to the combustion control section 6 and the vapor pressure rise period measuring section 1.

The output terminal of the measuring section γ is connected to a scale state determining section 9, and the determining section 9 is connected to a digital-to-analog converter 9a, a comparator 9b following it, and the other terminal of the comparator 9b. It consists of a potentiometer 9C.

Furthermore, the output terminal of the comparator 9b is connected to the input terminal of the alarm display section 10.

FIG. 3 shows the steam pressure from the time of startup, that is, the pressure sensor 5a.
The change over time (A) of the vapor pressure signal S1 output by the start command signal (13) from the start switch 8, and the measured vapor pressure signal (C) output by the third comparator 5d of the vapor pressure measuring section 5. , is a waveform diagram showing a comparison between the vapor pressure rise period signal outputted by the vapor pressure rise period measurement unit I and the reference signal IJ (D+).

In the above waveform diagram, as shown in Figure 3 (A+), the change over time from the start until the vapor pressure reaches a constant measurement set value M is shown by a solid line in a state where there is no scale adhesion. When the scale adhesion state is reached, as shown by the dotted line, the rising period TS' increases compared to that of the solid line ('1゛S).

Note that since the measurement set value M is set to a value lower than the steam pressure signal S1 corresponding to the lower limit steam pressure during operation, the combustion control unit 6 is in combustion mode, and the canned water continues to be heated.

In the above configuration, when the start switch 8 is manually turned on, the start command signal S5 is supplied to the water supply control section 3 and the combustion control section 6, and the boiler enters the combustion state. At the same time, the start command signal S5 is supplied to the steam pressure rise period measuring section 7 (FIG. 3(B)).

When the combustion control section 6 shifts to the combustion mode, the steam pressure of the boiler increases with time along the solid line in the absence of scale adhesion (FIG. 3 CA) a), and the steam pressure is equal to the pressure of the steam pressure measurement section 5. When asked by the sensor 5a, the vapor pressure measuring section 5 outputs a vapor pressure signal S1 corresponding to the above vapor pressure. The vapor pressure signal Sl is then guided to a third comparator 5d. On the other hand, the third potentiometer 5g is set to a measurement setting value M corresponding to a predetermined steam pressure lower than the lower limit steam pressure during continuous operation of the boiler (see Fig. 3).
Alb), detects that the vapor pressure signal S1 has reached the measurement set value M (FIG. 3 (AI C)), and outputs the measured vapor pressure signal S4 (FIG. 3 (C)).

The steam pressure rise period measurement unit T determines whether the steam pressure No. 46 S1 is from the initial value Period until measurement set value M is reached (3rd
(A) TS), that is, the built-in gate is opened over the vapor pressure rising period, the clock pulses are counted by a counter, and the vapor pressure rising period signal S6 is output, which represents the period Ts in a digital code ( Bud, 3
Figure (D) a).

The vapor pressure rise period signal S6 is sent to the scale state determination section 9.
The signal is sent to a digital-to-analog converter 9a, where it is converted into an analog signal and supplied to a comparator 9b ((1) a-' in FIG. 3).

On the other hand, in the potentiometer 9c, a reference signal S7 is set, which is an experimentally determined range of allowable scale adhesion (FIG. 3(r))b). Then, the comparator 9b compares and determines the magnitude relationship between the vapor pressure rise period signal S6 and the reference signal s7, and when the former S6 becomes larger than the latter S7, the output signal is inverted to "o". Therefore, as mentioned above, in a state where there is no scale adhesion, the vapor pressure rise period signal S6 is smaller than the reference signal s7 (Fig. 3, 1)). a', b), the scale adhesion state signal S8 is never output.

On the other hand, in a state where there is scale adhesion, the vapor pressure increases along the dotted line, and since the scale is a poor conductor of heat, the rising slope of the vapor pressure becomes gentle (Fig. 3(A) d). Then, the vapor pressure rise period Ill until the rising vapor pressure signal S1 reaches the measurement set value M (Fig. 3 e)
As s' becomes longer, the vapor pressure rise period signal s6 becomes larger than the reference signal S7 (Fig. 3 (D) c', d
), and the scale adhesion state determining section 9 outputs a scale adhesion state signal S8.

Then, in response to the scale adhesion state signal S8, the alarm display section 10 visually or audibly displays that the scale adhesion state has been reached.

As mentioned above, according to this brother, there is provided a steam pressure measuring means that receives a steam pressure signal from a boiler and outputs a measured steam pressure signal, and a steam pressure measuring means that receives a steam pressure signal from a boiler and outputs a measured steam pressure signal, and a steam pressure that is measured until the steam pressure signal reaches a set value for measurement. The vapor pressure rise period measuring means measures the rise period and outputs it as a vapor pressure rise period signal, and the scale adhesion state determining means determines the scale adhesion state based on the signal and a reference signal. By measuring the rise period until the steam pressure reaches a certain value when starting the boiler, and comparing this with a preset reference value, the state of scale adhesion in the water pipes can be determined. Compared to conventional methods, it is possible to observe the scale adhesion state with much higher accuracy and each time the operation is started, and with a short measurement sampling period, it is possible to measure the scale adhesion state virtually continuously. This has the excellent effect of allowing you to accurately determine when to perform scale removal work.

In addition, since a scale adhesion status signal indicating the scale adhesion status is automatically obtained, there is no need for the conventional troublesome work of disassembling and inspecting the boiler after blowing it out. There is also the effect that there is no negligence in the condition monitoring work, and the risk of missing the time for scale removal work is extremely reduced.

[Brief explanation of the drawing]

FIG. 1(A) is a block diagram showing the configuration of a small boiler system to which the configuration of the present invention can be attached; FIG. 1(13)
is a sectional view taken along the line A-A in FIG. 1), FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. B) and
FIG. 3 is a waveform chart showing a comparison between the measured vapor pressure signal (C), the relationship ([1)] between the vapor pressure rise period signal, and the reference signal. 1... Boiler 2... Water level detection section 3... Water supply control section 4... Water supply pump 5... Steam pressure measurement section 6. ...
... Combustion control section 7 ... Steam pressure rise period measurement section 8 ... Start switch 9 ... Scale adhesion state determination section 10 ...
・Alarm display section Sl...Steam pressure signal S4・
... Word 1 steam pressure measurement signal S5 ... Start command signal S6 ... Steam pressure rise period signal S7.
...Reference signal S8... To scale adhesion state signal 1...
...Measurement setting value X...Initial value procedure amendment November 19, 1982! t'11yl° Chief Michi Wakasugi No. 11 Daiden 1 ('1 display Showa 5711-Special W [Application No. 129299 2, title of invention Scale-i τ in boiler system]〃1-state training device 3i1) Correct Relationship with those who do 11rf'l! Samurai 5'1 applicant representative director
246 Agent 5tili 11 Order of 1111 Showa 57111
LIJlγ11 (U1', Send1) Showa, 1157 iu
Month 21) () Number of inventions increases due to oil stoppage U7
Target of oil stop

Claims (1)

[Claims] A pressure sensor 5a that outputs a steam pressure signal Sl corresponding to the steam pressure of the boiler, and a comparator 5d that detects that the steam pressure signal is a preset measurement setting value M and outputs a measured steam pressure signal S4. a vapor pressure measuring means 5 including;
Based on the start command signal S5 and the measured steam pressure signal S4, the steam pressure rise period until the steam pressure signal S+ reaches the measurement set value M from the initial value X at the time of startup is measured, and the measurement result is A vapor pressure rise period measuring means 7 outputs the vapor pressure rise period signal S6 as a vapor pressure rise period signal S6, and determines the scale adhesion state based on the magnitude relationship between the vapor pressure rise period signal and a preset reference signal S7, and determines the scale adhesion state. Scale adhesion state determining means 9 that outputs a state signal S8
A scale adhesion state measuring device in a boiler system, characterized by comprising: