JPS5986804A - Device for deciding and controlling state of concentration of boiler water 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 This invention continuously monitors the increasing tendency of impurity in can water due to concentration of can water in a boiler system.
The invention relates to canned water concentration determination devices and control devices.

In general, when a boiler system is operated for a long time, the canned water becomes concentrated, which increases the concentration of impurities such as dissolved solids contained in the canned water, causing bubbles to form on the surface of the canned water. .

It is known that the bubbles leave the air-water interface and get mixed into the steam, causing carryover and causing damage to related equipment, such as a balzo, connected to the boiler system.

Therefore, in order to prevent carryover, it is necessary to measure the flow of water or steam with a flowmeter, etc.
Although it is common practice to estimate the shrinkage degree of canned water, and when it increases to a certain extent, the canned water is blown out (hereinafter referred to as plowing) and replaced with new canned water. Since the economic burden of equipping a flowmeter is relatively large, it is generally difficult to employ a flowmeter, and instead of measuring the cumulative fuel consumption of a boiler system, Concentration of canned water is estimated by measuring the amount of water in a storage container, typically 1 μm, or by extracting a portion of the canned water and measuring its electrical conductivity. -r is often done.

However, when estimating the cumulative steam consumption based on the cumulative fuel consumption and further estimating the can water concentration based on the cumulative steam consumption, the efficiency of the boiler system is determined by the steam consumption (
It was difficult to expect high-accuracy measurement because it changed according to the load).

In addition, when measuring based on the count of paper storage containers such as drums, the minimum unit of measurement is extremely large and there is a large quantization error during measurement, so it is far from being able to measure continuous quantities. .

Furthermore, measuring cumulative fuel consumption using drums, etc. involves the tedious task of counting (2) and recording the number of drums, etc. in which the consumed fuel was stored. It was often the case that the cumulative frequency of occurrence and even the concentration of canned water could not be determined at all.

Furthermore, when estimating the concentration of canned water based on the electrical conductivity of canned water, only intermittent measurements can be made; It was not possible to continuously measure the increasing trend.

In such conventional boiler systems, it is not possible to accurately determine when to perform blowing, which leads to the canned water becoming extremely concentrated, causing frequent carryover, and causing damage to related equipment. It had the disadvantage of being extremely sensitive.

This invention is a boiler system that adopts water level control with the simplest configuration, that is, the feed pump is cycled based on a signal from a single water level detection probe installed in a water level detection section that communicates with the water pipe of the boiler. Generally, it is applied to a boiler system that adopts a water level control method that operates for a predetermined period (for example, a certain period of time), and its purpose is to eliminate the drawbacks of the above-mentioned conventional technology.
It is an object of the present invention to provide a can water concentration state determining device that highly accurately and continuously determines the concentration level of can water.

A further object of the present invention is to provide a can water solubility control device that automatically removes can water as appropriate in accordance with the above-mentioned determination output and maintains the concentration of can water within the allowable range of the boiler system. It is to be.

These objects are achieved by a device having the structure described in the claims.

As mentioned above, the water pump is operated periodically (continuously) for a predetermined period of time using only the integrated water level detection probe.
In a boiler system that uses a water level control method, as the canned water becomes more concentrated, the water level detection probe signal rises from the water supply start point of the water supply pump (the water level rises through the water level detection probe position). The inventor of the present invention has found that the time from the time when the water level detection prono signal rises to the time when the water supply is completed decreases, while the time from the time when the water level detection prono signal rises to the time when the water supply is completed decreases. This invention was devised by paying attention to this phenomenon.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1(A) is a longitudinal sectional view showing the configuration of the boiler system,
Boiler 1 is shown in cross section. FIG. 1(B) is a sectional view taken along the 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 peripheral surface of the wall 1a, and the water pipe #1b is a hollow cylinder, and its lower end is an annular lower header 1c (ice chamber). , and its upper end is also an annular upper header ld (
steam room), lower header 1c and water pipe 1
Canned water is stored in the lower part of b.

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

A lower end portion of the combustion chamber 1e communicates with a flue 1k through a number of hollow portions of water pipes 1b. A communication pipe 11 extends from the upper header 1d to the outside of the wall 1a and communicates with the lower header IcK.

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 in the can. A water supply control section is connected to the water level detection section 2, and its output terminal is connected to an electric motor 4a 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.

Furthermore, a pressure detection unit 5 is connected to the upper part of the communication pipe 1.
Its output terminal is connected to the combustion control section 6. The combustion control unit 6 has control signal lines 6a to 6c extending from it to the electric +! ! 1
f, electrode +llj, and the inlet pipe of the fuel pump 6d communicate with a fuel tank (not shown) 2, and its discharge pipe 11. Then, the lower pipe header 1c is the blow pipe 1n.
The steam pipe 1q extends from the upper header 1d and is connected to the steam/water separator #1r.
The steam in the steam pipe 1s is sent to a desired steam load (not shown), and the separated water is passed through the return pipe 1.
It is returned to the lower header through L. At the lower part of the return pipe 1, a blow valve 1u for blowing out the canned water in the water pipe as appropriate is opened by automatic control to be described later.

In the above boiler system configuration, when generating steam, the prop 1g is driven by the electric motor 1f and the air passage 1h is
A high voltage is applied to the electrode rod 1J while air is being pumped into the nozzle rod 11 to ignite the fuel injected from the tip of the nozzle rod 11, which is combusted within the combustion chamber 1e. The high-temperature combustion gas generated by the burnt combustion enters the hollow part of the suiei 1b from the lower end of the combustion chamber 1e, passes through this, reaches the flue 1k, and is exhausted. During this time, heat exchange takes place and the canned water in the water WI b is heated and turned into steam, which is accumulated in the lower header 1d and then transferred to the steam pipe 1q, the steam separator 1r, and the steam pipe 1s.
The steam load is supplied to the steam load through the

Regarding combustion control, the steam pressure in the upper header 1d is extracted through the communication pipe 11 and supplied to the pressure detection section 5, and the pressure detection section 5 is connected to the steam pressure in the upper header 1d set in advance. As soon as it is detected that the lower limit vapor pressure has been reached,
Similarly, when it is detected that the lower limit vapor pressure signal has reached the upper limit vapor pressure, the upper limit vapor pressure signal is sent to the combustion control section B.

The combustion control unit 6 continues to consume steam and the upper header 1d
When the vapor pressure in the tank drops and a lower limit vapor pressure signal is received, the control signal line 6a is used to start the electric motor 1f, and the fan 1g blows air through the air passage 1h while falling on its side. J
Through signal line 6b? (f.

While applying a high voltage to the pole rod 1J, the control signal line 6c
The fuel pump 6d is started through the nozzle rod 1, and the fuel injected from the nozzle rod 1 is ignited to start combustion. Furthermore, the generation of steam continues and the steam pressure increases, and the pressure detection unit 5 outputs an upper limit steam pressure signal. When this happens, the fuel pump 6a is stopped via the control signal line 6c, and combustion is stopped by cutting off the fuel supply, and the electric motor 1f is stopped via the control signal line 6a after the combustion gas is discharged. Cut off air from 71g.

By controlling the combustion on and off, the steam pressure in the upper header 1d can be maintained at a pressure value between the meat 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, the air-water interface in the communication pipe 11,
In other words, the water level detection unit 2 detects changes in the canned water level in the water pipe 1b.
to communicate. A single water level detection probe (not shown) is arranged in the water level detection section 2 . Any suitable known water level sensor can be used as the detection probe. The output of the water level detection probe is sent to the water supply control unit B.

The water supply system @j unit 6 operates periodically (intermittently) with the falling edge of the output signal of the water level detection probe (indicating that the water level is falling through the detection signal of the water level detection probe) as a reference point. It has a shallow function that operates the water supply pump for a predetermined period (for example, a fixed period), and can be composed of, for example, a water level drop detection section and a timer.

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

In addition, for blowing canned water, in addition to the automatically controlled electromagnetic blow valve 1u described later, by manually opening the blow cock 1p, the canned water in the lower header 1c and the water pipe 1b is allowed to flow through the water control #1r1. It is possible to blow some or all of the

In addition, the electromagnetic blow valve 1u may be installed in parallel with the manual blow cock 1p.

Nao, 7" lower 1g, airway 1h, nozzle rod 1], electricity 4
The burner, which can be used for 1F and 1J, is not limited to this type of burner.If necessary, it is sufficient to heat the canned water in the water pipe 1b to generate steam, so in general, an electric heater or the like is also used. Any heating device including the above may be used.

Similarly, the combustion side (11 section 6) may also be a heating control section that turns on and off the heating device.

FIG. 2 shows a block diagram of the water supply control section and the canned water concentration determination section, and the output of the probe 100 of the water level detection section 1-6 is supplied to the rise detection section 110 and the fall detection section 120. The lowering detection unit 120 constitutes one element of the water supply control unit B, and its output is determined by the filter timer 1 (130) in the remaining elements of the water supply control unit.
). Output of timer 1 (or fall detection section 12
0 output) is the timer 2 (140) S ta, I.1.
supplied to the input. On the other hand, the output of the ``second rise detection section 110'' is supplied to the 5top input of the timer 2 (140), and the output of the timer 2 (140) is input to the counter 150. M
The I counter 150 outputs a canned water concentration signal as appropriate.

FIG. 6 is a waveform diagram illustrating a determination method for can water concentration according to the present invention. FIG. 6 assumes that the water level detection probe is placed at an intermediate water level. Furthermore, as a control method by the water supply control unit B, it is assumed that the water supply pump is started after a certain period of time from the falling point of the water level detection prono signal (when a fall is detected), and the water supply is continued for a certain period of time.

In Figure 6, curve a of the water level illustrates the change in the water level of canned water when concentration is not progressing, and the broken line curve b
exemplifies changes in the water level of canned water at a stage where concentration has progressed. In curve a, time 1 is the time when the water level passes 11n below the probe position, that is, the time when the probe signal falls, and at time 2, which is a certain period of time after time 1, timer 1 (second Water supply starts with the operation shown in Figure 1(t).At time 6, the water rises due to this water supply and passes the position of the water level probe 1-ro, that is, the rise of the probe signal.Water supply pump is timer 1 (130
, see Figure 2), water supply is completed at time 4, which is a certain period of time after time 2. When the water supply is completed (1-), the water level gradually decreases due to the steam load, and at time 5 (1), the water level probe signal falls again and the next cycle begins.

As the concentration of the canned water progresses, the probe 100 of the water level detection unit will observe a water level higher than the true water level due to the bubbles in the canned water, and when water supply is started at time point 2, the bubbles will decrease or disappear. Observe the water level close to the actual water level. As a result, the observed water level of the detection unit exhibits a tendency as shown by the broken line.

The progress of concentration of canned water is shown at time points 1, 2. The following changes occur in the time difference between 4 and 4. That is, as enrichment progresses, the time between time points 2 and 6 tends to increase;
The time between point 0 and point 4 has a decreasing direction.

Therefore, according to the present invention, when the time between two time points is outside a predetermined range where the length between the time points changes as the value linearization progresses, the concentration of canned water is estimated to be 1- I try to do that.

For example, in order to monitor the time difference between water supply 1jij start time 2 and water level detection probe signal rise time 6, in FIG. (which is also a water supply command) to the rise of the output signal of the rise detection unit 110, and compared this with the time internally set in the timer 140, and found that the checked time was longer than the set time. Output a signal when

Preferably, a 31 number counter 150 is connected after the timer 140. The counter 150 counts the number of output pulses sent from the timer 2 every predetermined period corresponding to a plurality of water level cycles, and outputs an output if it matches the number of the plurality of cycles. In other words, the device 150 outputs an enrichment status signal when a predetermined increase in the time between time points 2 and 6 is continuously observed over a plurality of consecutive cycles. Out-1-6 Instead of the above, the time from the probe signal fall point 1 (fall detection point) to the probe signal fall point (rise detection point) may be monitored. In this case, as shown in FIG. In place of connecting the output of the water supply command output timer 1 (130) to the human power of the monitoring timer 2 (140), connect the output of the descent detection section 120 to the 5tart input of the timer 2. , selection input (s) of monitoring timer 2 (140)
tart, input and 5top input) may be two points in time whose time difference changes as the canned water becomes more concentrated. Therefore, in addition to the above, the monitoring timer is started at probe fall point 6 (rise detection point),
The timer may be stopped at time 4 when water supply is completed (or at time 5 when the probe falls (downward detection time), which is the start of the next cycle. However, in this case, the length between both times is equal to the length of the canned water. Since it tends to decrease as the can water becomes more concentrated, the timer is set to 1 so that when the check time becomes less than the internally set time length of the monitoring timer, the timer outputs a judgment output indicating that the can water is concentrated.

In particular, in cases where a textured canned water concentration signal is not required, the counter 150 may be omitted and the output of the monitoring timer 2 (140) may be used as the canned water concentration signal.

FIG. 4 is a waveform diagram similar to FIG. 6 when a single water level detection probe 100 is placed at the water supply start level. In this case, time points 1 and 6 in the time chart of FIG. This is the same as the case in FIG. 6 except that they match.

Now, it is preferable to automatically control the above-mentioned blow valve using the concentration state signal obtained as described above. An example of the configuration of such an operating circuit is shown in FIGS. 5 and 6.

Figure 5 shows a method in which a timer is used to end the no-row.
When condensation is detected, an electromagnetic blow valve is activated for a predetermined period of time to partially drain the canned water. Figure 6 shows the case where condensation is detected using only a water level sensor. The magnetic blow valve is operated until the canned water in the water pipe reaches a certain level.

The details of FIGS. 5 and 6 are as follows.

In FIG. 5, Rr is a contact point of a concentration detection relay (not shown) provided on the output side of the concentration determination section of FIG. A self-holding relay contact x-1 is connected in parallel with this concentration detection relay contact Rf, a timer contact T-1 is connected in series with both these contacts, and a timer T-1 is connected in series with the timer contact T-1.
, the coil S of the electromagnetic valve 1u shown in FIG. 1A and the self-holding relay X are connected in parallel. therefore,
When concentration is detected and the output relay is energized, its contact X-1 is closed by the self-holding relay ) is activated, and the canned water in the water pipe begins to blow.

When a predetermined period of time has elapsed after the start of the blow, the contact T-'l of the timer T is opened, the electromagnetic blow valve coil S■ is released, and the blow ends.

Note that the water supply pump may be configured to be prohibited from operating while the timer is operating (during automatic plowing).

The circuit shown in Fig. 5 connects the concentration detection output relay contact Rf and the self-holding relay contact The contact EL of the water level sensor (located below the water level detection probe) is connected, and the self-holding relay X is connected to the operating coil S of the electric plow valve, which is configured in series and parallel to the contact of the water level sensor. Therefore, when the concentrated state of the canned water is detected and the output relay contact Rf is closed, the operating coil SV of the electromagnetic blow valve is excited and the canned water starts to swell. As the canned water is plowed, the water level decreases, and when it reaches the detection level of the water level sensor, the contact EL opens in response to the signal, releasing the operating coil, and the electromagnetic blow valve closes, ending the plowing. As before, it is recommended to prohibit the operation of the water pump during self/assistance blowing.

By blowing the canned water as described above and subsequently supplying water to the water pipe from the water supply pump 4 (FIG. 1A), the concentration of the canned water in the water pipe is diluted.

FIG. 7 schematically shows how the can water concentration is controlled by this plow water supply control. In Fig. 7, the vertical axis shows the concentration of water, and the horizontal 1llllll shows time. This is within the allowable range of the boiler system used.As shown by curve a, the concentration of canned water in the water pipe increases with the passage of operating time. According to the invention, when the concentration of the canned water reaches the set level Ks as shown in the dot, the canned water is automatically blown, and by the subsequent water supply, the concentration is as shown schematically at the point C. If the canned water is not blown, it will be reduced to 1.
- Then, the concentration of canned water in the water pipe continues to increase as shown by ruptured aC, and the situation becomes dangerous and can cause damage to the boiler system.

Both of the circuits shown in FIGS. 5 and 6 described above provide control for blowing out some, but not all, of the canned water in the water pipe. In principle, it is possible, but if you use a system that automatically blows all canned water for one pot, it is necessary to interlock the burner and water pump, and it is necessary to interrupt boiler operation. No. On the other hand, the partial blower type according to the above-mentioned configuration example has the advantage that the boiler can continue to operate, and is suitable when steam is required for a long period of time.

[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, and FIG. 1(B) is a sectional view taken along line AA of the boiler 1 in FIG. 1''(A). , second
The figures relate to an embodiment of the present invention, and are a block diagram showing the configuration of a water supply control section and a concentration determination section, FIGS. 6 and 4 are waveform diagrams of main parts in the configuration of FIG. 2, and FIG. 6 is a diagram for explaining the blow valve operating circuit according to the timer method, FIG. 6 is a diagram for explaining the blow valve operating circuit according to the water level seven pump method, and FIG. 7 is a diagram for explaining the canned water concentration control side 1. 1...Boiler, 2...Water level detection section, 6.
...Water supply control unit, 4...Water supply pump, 100.
...Water level detection prologue, 110...Rise detection section, 12
0...Descent detection section, 160...Water supply control timer,
140...Concentration monitoring timer, 15[]...Concentration determination counter. Procedural amendment written in figure L7 (method) 1. Indication of the case Showa off year '4 present Application No. 7 θ No. 0 Dedicated 6. Person making the amendment Relationship with the case Applicant's address 2 Ruled (tyu3) 11, to 4 Toya soil γL catty 11FF
Chotsu-4, Agent

Claims (1)

[Claims] (+1 Water level control is performed by periodically operating a water pump for a predetermined period of time based on a signal from a single water level detection probe provided in a water level detection unit communicating with a water pipe of a boiler. In the boiler system, the falling and rising points of the M water level detection Zorope signal,
Select at least two points out of the water supply start point and water supply end point of the water supply pump, the length of which changes depending on changes in the concentration of canned water, and determine whether the period between these two points is outside a predetermined range. 5. A device for determining a condensed state of canned water in a boiler system, characterized in that the canned water is determined to be in a condensed state when the In the device (\), one of the two time points is the time point at which water supply starts, and the other time point is the time point at which a water level detection probe signal indicating a rise in the water level rises. (3) Scope of Claim 1 In the device, one of the two points of time is the rising point of the water level detection signal indicating a rise in the water level, and the other is the point of completion of water supply. (4) Claim 1 In the device, the two points in time are a starting point at the falling point of the water level detection probe signal representing a falling water level, and an ending point at the rising point of the water level detecting probe signal representing a rising water level. (514f-Claims In the apparatus according to item 1, the two points in time are such that the starting point is the rising edge of the water level detection probe signal indicating a rise in the water level, and the ending point is the falling edge of the water level detection probe signal. (6) In a boiler system in which water level is controlled by periodically operating a water pump for a predetermined period of time based on a signal from a single water level detection probe provided in a water level detection section communicating with a water pipe of the boiler, The falling and rising points of the water level detection probe signal,
Among the water supply start time and water supply end time of the water supply pump, at least two time points whose lengths between the time points change depending on changes in the concentration of canned water are used as selection inputs, and the period between these two time points is determined. A boiler system characterized in that canned water is determined to be in a concentrated state when a water level detection unit detects that the water level is out of a predetermined range over a plurality of consecutive periods of water level change. canned water concentration status determination device. In the device according to claim 6, one of the two time points is the time point at which water supply starts, and the other time point is the time point at which a water level detection probe signal indicating a rise in the water level rises. (8) Patent Claim In the device according to claim 6, one of the two time points is the rising time of a water level detection probe signal indicating a rise in the water level, and the other is the time point at which the water supply is completed. In the apparatus described in item 6, the two points in time are a starting point at which the water level detection prono signal falls, indicating a falling water level, and an ending point indicating a rising water level.
It must be at the rising point of the water level detection signal. 00) In the device according to claim 6, the two points in time are such that the starting point is the rising point of the water level detection prono signal indicating a rise in the water level, and the ending point is the falling point of the water level detecting prono signal. . Old) In a boiler system in which the water level is controlled by periodically operating a water pump for a predetermined period of time based on a signal from a single water level detection probe installed in a water level detection section that communicates with the water pipe of the boiler, The falling and rising points of the detection probe signal,
Among the water supply start time and water supply end time of the water supply pump, at least two time points whose lengths between the time points change depending on changes in the concentration of canned water are used as selection inputs, and the period between these two time points is determined. Judgment means for determining that the canned water is in a concentrated state when it falls outside a predetermined range and outputting a canned water concentration signal, and automatically operating a blow valve in response to the signal from the determining means. 1. A can water concentration control device for a boiler system, characterized in that it is provided with an actuating means. (121 In a boiler system in which the water level is controlled by periodically operating the water pump for a predetermined period of time based on a signal from a single water level detection probe installed in the water level detection unit communicating with the water pipe of the boiler, The falling and rising points of the water level detection probe signal,
Among the water supply start point and water supply end point of the water supply pump, at least two points whose length changes depending on the change in the level of canned water are used as selection inputs, and the period between these two points is determined. When it is detected that the water level is out of a predetermined range over a plurality of consecutive cycles of water level change in the water level detection section, it is determined that the canned water is in a concentrated state and a canned water concentration signal is output. 1. A can water concentration control device for a boiler system, comprising: means for controlling the concentration of canned water in a boiler system; and an operating means for automatically operating a blow valve in response to a signal from the determining means.