JPS58195702A - Measuring device for evaporation 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 an evaporation amount measuring device for automatically measuring the load of a boiler system, that is, the amount of evaporation, and particularly relates to a heating control system for heating canned water in a boiler system. An evaporation amount measuring device that measures evaporation amount based on the period during which the rising and falling vapor pressure rises between first and second reference values set between the upper and lower limit vapor pressures through intermittent control. It is.

In general, in boiler systems, it is known that during long-term operation, factors that inhibit operation increase in accordance with the cumulative amount of evaporation, such as carryover and scale growth due to concentration of canned water.

Furthermore, since there are control targets in the boiler system, such as the amount of water supplied, that are controlled appropriately depending on the amount of evaporation, it is necessary to judge whether these controls are being performed appropriately based on the amount of evaporation. However, backup measures are taken in case of unsuitability, and it is also known that the amount of evaporation is important basic data for the operational management of boiler systems.

Therefore, in order to understand the amount of evaporation as basic data for operation management, the flow rate of steam load is often measured using a flowmeter, but in small boiler systems, Since the economic burden of equipping a flow meter is relatively large, it has generally been difficult to employ it.

Therefore, with conventional small boiler threads, it was not possible to accurately determine the amount of evaporation, which not only made it impossible to provide sufficient backup protection for water supply control systems, etc., but also caused equipment damage and scaling due to carryover. The disadvantage was that the risk of water pipe burnout due to growth was extremely large.

In view of the set point during measurement of evaporation amount in a boiler system based on the above-mentioned conventional technology, an object of the present invention is to control the rising and falling vapor pressure by intermittent control of the heating control system without using a flow meter. Measuring the reference pressure rise period required for the pressure to rise from a second set value set during the pressure to a first set value similarly set, and calculating the amount of evaporation based on the measurement result. The present invention aims to eliminate the above-mentioned drawbacks and provide a sophisticated evaporation amount measuring device in a boiler system that can automatically measure the evaporation plate.

The configuration of the present invention in accordance with the above object includes a pressure sensor that outputs a steam pressure signal corresponding to the steam pressure in the water pipe, and a pressure sensor that detects that the steam pressure signal has reached an upper and lower limit set value corresponding to the upper and lower limit steam pressure. and a first and second comparators to form a first steam pressure detection section, and a heating device for heating the water tube in response to output signals from each of the first and second comparators. Typically, a heating control unit is provided to start or stop the burner, and when the vapor pressure in the water pipe decreases due to airless consumption and reaches the lower limit air pressure, a first comparator detects this. Then, a lower limit steam pressure signal is sent to the heating control unit to start the heating device, and when the steam pressure in the water pipe increases with the start of heating and reaches the upper limit steam pressure,
The second converter detects this and sends an upper limit vapor pressure signal to the heating control unit to stop the heating device.
In a boiler system equipped with an intermittent heating control system, a second temperature sensor outputs a steam pressure signal corresponding to the steam pressure in the water pipe, and the steam pressure signal is set between the upper limit setting value and the lower limit grass setting value. a third comparator that detects that the first reference value is the first reference value and outputs the first reference vapor pressure signal; and a fourth comparator that detects that the second reference vapor pressure signal is the second reference value and outputs the second reference vapor pressure signal, and the fourth comparator outputs the second reference vapor pressure signal. The reference pressure rise period from the output to the output of the first reference steam pressure signal is measured, and a calculation unit is attached to the evaporation to determine the specific boiler system specific to each boiler system determined according to the upper and lower limit steam pressure of 0η. Calculate the quotient by dividing the constant by the reference pressure rise period measured by the reference pressure rise period measurement unit, and perform the calculation of subtracting the quotient from the maximum evaporation amount specific to each boiler,
It is characterized in that the calculation result is output as an evaporation amount signal.

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

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

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

A combustion chamber 1e is located in the center of the boiler 1 surrounded by water pipes 1b.
is formed.

A blower 1 driven by an electric motor 1f is installed above the boiler 1.
An air passage 1h communicating with g is provided, and a nostle rod 1i and an electrode rod 1J are vertically disposed within the air passage 1h to form a lower part of the heating device.

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

A water level gauge 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 . An inlet pipe of the water supply pump 4 communicates with a water source (not shown), and a discharge pipe thereof communicates with the upper header 1C.

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

In the configuration of the boiler system described above, when generating steam, the 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 1i. The injected fuel is ignited and combusted within the combustion chamber 1e. High-temperature combustion gas generated by such combustion enters the hollow part of the water pipe 1b from the lower end of the combustion chamber 1e, passes through it, reaches the flue 1k, and is exhausted.

During this time, heat exchange 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 upper header 1d is extracted through the communication pipe 1l and supplied to the steam pressure detector 5, and the steam pressure in the lower header 1d is set in advance. When it is detected that the lower limit vapor pressure has been reached, the lower limit steam 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.
send to

The combustion control unit 6 continues to consume steam and the upper header 1d
When the vapor pressure in the interior decreases and a lower limit vapor pressure signal is received from the vapor pressure detector 5, the electric motor 1f is started through the control signal line 6a', the air passage 1h is purged with air using the blower 1g, and then control is performed. A high voltage is applied to the electrode rod 1j through the signal line 6b', and the fuel pump 6d' is started through the control signal line 6c', so that fuel is injected from the nozzle rod 1i.

When the fuel is ignited to start combustion, the steam continues to be generated and the steam pressure rises, and an upper limit steam pressure signal is received from the steam pressure detector 5, the fuel pump 6d' is activated via the control signal line 6C'. The combustion is stopped by cutting off the fuel supply, and after the combustion gas is 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, the steam pressure in the upper header 1d can be maintained at a pressure value between the two positive pressure values preset as the upper and lower steam pressure limits.

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

Furthermore, regarding the water supply system, the air-water interface in the communication pipe 11,
That is, the water level detection unit 2 detects changes in the can water level in the water pipe 1b.
When the water level detection section 2 detects that the can water level has reached a preset lower limit water level, it transmits a lower limit water level signal, and similarly, when it detects that the can water level has reached the upper limit water level, it transmits an 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 causes the water supply pump 4 to pass through the lower header 1C. Water supply to the shite water pipe 1b 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, an electric motor 4a is stopped to cut off the water supply to the water pipe 1b.

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

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

Further, when blowing canned water, by opening the blowing tank 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 1i, electrode rod 1
The burner made of Any device is fine.

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

Next, the structure and operation of the embodiment of the present invention will be explained based on FIGS. 2 to 6 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 first steam pressure detection section 5 includes a pressure sensor 5a to which the steam pressure in the upper header 1d is guided through a communication pipe 1l, and a first steam pressure sensor 5a whose first input terminal is connected to the output terminal of the pressure sensor 5a. , second comparators 5b, 5c, and first,
It consists of reference voltage sources 5d and 5e connected to the second input terminals of second comparators 5b and 5C, respectively.

The heating control unit 6 includes a flip-flop 6b, in which the output terminal of the first comparator 5b is connected to its set terminal, and the output terminal of the second comparator 5C is connected to its reset terminal through an inverter 6a; A relay 6 has a positive phase output terminal connected to one end of the relay 6b through a driver 6C, and the other end is connected to a power supply 6d.
contacts 6e', 6e'', 6e of relay 6e.
"' is inserted between each of the control signal lines 6a', 6b', and 6c' for controlling the electric motor 1f, the electrode rod 1j, and the fuel pump 6d' and the power source.

The second steam pressure detection unit 7 includes a pressure sensor 7a to which the steam pressure in the upper header 1d is guided through the communication pipe 1l, and a third pressure sensor 7a whose first input terminal is connected to the output terminal of the pressure sensor 7a. , fourth comparators 7b, 7c, and third,
and reference voltage sources 7d and 7e connected to the second input terminals of fourth comparators 7b and 7c, respectively.

The reference pressure increase period measuring section 8 includes a third comparator rb.
The output terminal of the fourth comparator 7c is connected to its reset terminal through the inverter 8a, and the output terminal of the fourth comparator 7c is connected to its set terminal through the inverter 8b. An AND gate 8e whose input terminal is connected to the output terminal of the clock pulse oscillator 8d and whose other input terminal is connected to the positive phase output terminal of the flip-flop 8C.
and a counter 8f whose input terminal is connected to the output terminal of the AND gate 8e, and a counter 8f whose input terminal is connected to the positive phase output terminal of the flip-flop 8C and whose output terminal is connected to the clear terminal of the counter 8f. Consists of 8g stable multivibrator.

One input terminal of the evaporation amount calculating section 9 is connected to the output terminal of the counter 8f, and its control terminal is connected to the flip-flop 8f.
It consists of a calculator 9a connected to the positive phase output terminal of C, a constant setter 9b and a maximum evaporation amount setter 9C whose output terminals are connected to the other input terminal of the calculator 9a. 10 is a display section connected to the evaporation amount calculation section 9d.

FIGS. 3 and 5 show the change (A) in the vapor pressure in the upper header 1d extracted to the communication pipe 1l, and the upper and lower limit vapor pressure signals (B) output by the first and second comparators 5b and 5C. )(C)
is compared with the positive phase output signal (D) of the flip-flop 6b, and is further compared with the first and second reference vapor pressure signals (E) and (F) output by the third and fourth comparators 7b and 7C. , each positive phase output signal (G) of flip-flops 8C and 11c
FIG. 3 is a waveform diagram showing a comparison of (H), (J), and (K).

In the above configuration, first, the operations of the first vapor pressure detection section 5 and the heating control section 6 will be explained as follows.

The pressure sensor 5a responds to the steam pressure in the upper header 1d guided through the communication pipe 1l and outputs a corresponding steam pressure signal S1.
) As shown in a, when the vapor pressure is higher than the lower limit vapor pressure, the reference voltage VL is equal to the lower limit set value of the vapor pressure signal S1, which corresponds to the lower limit vapor pressure supplied from the reference voltage source 5d. Since the vapor pressure signal S1 becomes larger than the current value, the first comparator 5b detects this and operates as shown in FIG. 3(B)b.
As shown in the figure, "1" is output.

Then, the steam pressure decreases as the steam is consumed or the temperature decreases, and as shown in No. 3 m(A)c, when the lower limit steam pressure is reached, the steam pressure signal S1 becomes smaller than the reference voltage ■L. , detecting this, the first comparator 5b outputs "0" as shown in FIG. 3(B)d.

The flip-flop 6b receives the inversion of the output signal of the first comparator 5b from "1" to "O" as the lower limit vapor pressure signal SL at the set terminal, and sets the flip-flop 6b to "1".
The positive phase output signal is as shown in Fig. 3 (D) e.
0” to “1”. Upon receiving this signal, the driver 6C becomes conductive, the relay 6e is excited, the contacts 6e', 6e'', and 6e''' are closed, and power is supplied to the motor 1f, electrode rod 1j, and fuel pump 6d'. As a result, the canned water is heated.

Thus, while the flip-flop 6b is at "1", heating continues, and the vapor pressure continues to rise, as shown in FIG. 3(A)f.

Eventually, as shown in FIG. 3(A)g, when the vapor pressure reaches the upper limit vapor pressure H, the vapor pressure signal S1 is supplied from the reference power source 5e. , which is smaller than the reference voltage VH equal to the upper limit set value of the vapor pressure signal S1, which corresponds to the upper limit vapor pressure H, as shown in FIG. 3(C)h.
The second comparator 5C, which had been outputting “C
) "1" is output as shown in i.

The inversion of the output signal of the second comparator 5C from "0" to "1" is performed by the inverter 6a.
The signal is inverted to "0" and supplied to the reset terminal of the flip-flop 6b as the upper limit vapor pressure signal SH, thereby resetting it to "0".

Then, as shown in FIG. 3(D)j, since the positive phase output signal of the flip-flop 6b becomes "0", the relay 6e
is in a de-energized state, contacts 6e', 6e", and 6e"' are opened, and heating of the canned water is stopped.

In this way, the period T1 from when the heating device starts to when it stops (hereinafter referred to as heating period) is specified by the period during which the flip-flop 6b is set to "1", and furthermore, when the heating device stops, During the period T2 from start to start (hereinafter referred to as heating stop period), the flip-flop 6b is
0)).

After heating is stopped, as shown in Fig. 3(A)k, the steam pressure decreases again as steam is consumed or the temperature decreases.
Until the lower limit vapor pressure is reached, the flip-flop 6b remains at "O", forming a heating stop period T2, and then the same operation is repeated until the vapor pressure reaches the upper limit vapor pressure and the lower limit vapor pressure. kept between.

Next, the operations of the second vapor pressure detection section 7 and the reference pressure rise period measurement section 8 will be explained as follows.

In response to the steam pressure in the upper header 1d connected in parallel with the pressure sensor 5a in the first steam pressure detection section 5 and guided through the communication pipe 11, the second pressure sensor 7a responds to the steam pressure in the upper header 1d. A vapor pressure signal S1' is output. At this time, as shown in Figure 3 (
A) As shown in a, when the vapor pressure is lower than the second reference vapor pressure B, the vapor pressure signal S1' corresponding to the second reference vapor pressure B supplied from the reference voltage source 7e is Since the vapor pressure signal S1' is smaller than the reference voltage VS which is equal to the second basic setting value, the fourth comparator 7C detects this and outputs "0" as shown in FIG. 3(E)m. " is output. Then, as shown in FIG. 3(A)n, when the vapor pressure reaches the second reference vapor pressure B, the vapor pressure signal S1' becomes larger than the reference vapor pressure VB, so this is detected and the fourth As shown in FIG. 3(E)o, the comparator 7C of
" is output.

The output signal of the fourth comparator 7c is inverted from "O" to "1" by the inverter 8b.
'' and is supplied to the set terminal of the flip-flop 8C as the second reference vapor pressure signal SB, so the flip 70 knob 8C is set to ``1'' and its positive phase output signal is As shown in Figure 3 (G) p, “0
” to “1”.

Furthermore, as shown in FIG. 3(A)q, when the vapor pressure reaches the first reference vapor pressure A, the vapor pressure signal S1' changes to the first reference vapor pressure supplied from the reference power source 7d. handle. The third comparator 1b outputs "0" as shown in FIG.
starts to output "1" as shown in FIG. 3(F)S.

The inversion of the output signal of the third comparator 7b from "0" to "1" is performed by the inverter 8a.
0'' to the first reference vapor pressure signal SA.
is supplied to the reset terminal of the flip-flop 8C, and reset it to "0".

Then, as shown in FIG. 3(G)t, the positive phase output signal of the flip-flop 8C becomes "0".

In this way, during the heating period T1, the period when the flip-flop 8c is "1" is the reference pressure increase period t.
It represents 1.

For example, when the amount of evaporation (steam load) increases in the step of increasing steam pressure, the amount of heat flowing into the boiler system by heating the canned water and supplying the canned water, and the amount of heat flowing out from the boiler system due to heat radiation. While the amount of heat is approximately constant during the heating period during steady operation, the amount of heat flowing out from the boiler system due to evaporation of canned water increases in proportion to the amount of evaporation, so more heat is taken away from the boiler system. Figure 3 (A)
As shown in f', the slope of increase in vapor pressure becomes slower.

Therefore, when the amount of evaporation increases, Fig. 3 (A) n'
At the point in time, as shown in FIG. 3 (H) p', the flip-flop 8C is inverted to "1" and the transition to the reference pressure increase period begins, and at the time in FIG. As shown in (H) t', the flip-flop 8C is inverted to "0", so a standard pressure increase period t1' is formed which is longer than the standard pressure increase period t1 before the amount of evaporation increases. be done.

When considering quantitatively the change in the reference pressure increase period t1 that depends on the change in the amount of evaporation, the amount of evaporation GS is expressed by the following formula.

However, if , and the feed water enthalpy is constant, both are constants unique to each boiler system.

Furthermore, the symbols in the above formula are: η... Boiler efficiency (excluding heat radiation loss) B...
...Fuel consumption (flow rate) Hu...Calorific value of fuel IW...Enthalpy of feed water Gs...Amount of evaporation (flow rate) ISM--...Steam Enthalpy (average value of enthalpies corresponding to the first and second reference steam pressures) QB... Heat radiation amount (heat flow rate) of the boiler UA...
...The internal thermal energy UB held by the boiler system at the end of the reference pressure increase period t1 corresponding to the first reference steam pressure A...The reference pressure corresponding to the second reference steam pressure B This is the internal thermal energy held by the boiler system at the start of the rising period t1.

Therefore, in formula (1), C=CB-CR・・・・・・・・・・・・・・・
(2), the evaporation amount Gs is expressed as.

Further, C represents the amount of evaporation when the reference pressure increase period t1 is infinite, that is, the maximum amount of evaporation unique to each boiler system.

Also, the reference pressure increase period t10 at Gs=0 is t10=Cv/C.
...... (4), and even if the amount of evaporation (steam load) is zero, the standard pressure rise period t10 mainly compensates for the thermal energy that flows out due to heat radiation from the boiler, and the boiler system is the minimum reference pressure rise period required to maintain the operating condition.

Then, the reference pressure increase period t expressed by the above equation (3)
FIG. 4 is a graph illustrating the relationship between 1 and the evaporation amount Gs.

In this way, the reference pressure increase period t1 of the boiler system is specified to a value unique to each boiler system according to the evaporation amount Gs, so if the reference pressure increase period t1 is measured and specified, the above (1) to ( 3) The amount of evaporation Qs can be calculated according to the formula.

Next, returning to FIGS. 2 and 3, the operations of the reference pressure increase period measuring section 8 and the evaporation amount calculating section 9 will be explained as follows.

During intermittent control of the heating device, the positive phase output signal of the flip-flop 6b is, for example, as shown in FIG. 3(D).
It becomes "1" during the heating period T1. In response to this positive phase output signal, the AND gate 8e opens only during the heating period, and the clock pulse from the clock pulse oscillator 8d is guided to the counter 8f to be counted.

Then, as shown in FIG. 3(D)j, when the flip-flop 8C is inverted from "1" to "0", its positive phase output signal is inverted from "1" to "0", and the output signal is inverted from "1" to "0". is closed and the supply of clock pulses to the counter 8f is cut off, and a digital code representing the reference pressure increase period t1 is generated in the counter 8f and outputted as a reference pressure increase period signal S2.

At the same time, the arithmetic unit 9a receives the inversion of the positive phase output signal of the flip-flop 8C from "1" to "0" at the control terminal, and executes arithmetic processing to be described later.

After the arithmetic processing by the arithmetic unit 9a is completed, the positive phase output signal of the flip-flop 8C changes from "1" to "
Upon reversal to "O", the triggered monostable multivibrator 8g, which had been in a quasi-stable state, returns to a stable state and sends a clear pulse to the clear terminal of the counter 8f, so the counter 8f is cleared. You can prepare for the next measurement.

During this time, that is, before the counter 8f is cleared, the arithmetic unit 9a sends a constant signal S representing the constant Cv preset to the constant setter 9b, which is a digital switch or the like.
3 by the reference pressure increase period signal S2 outputted by the counter 8f to calculate the quotient, which further represents the maximum evaporation amount C preset in the maximum evaporation amount setting device 9C, which also consists of a digital switch etc. The maximum evaporation amount signal S4 is read, the above quotient is subtracted from it, and the calculation result is outputted as the evaporation amount signal S5.

The evaporation amount signal S5 obtained in this manner is the calculation result of , and therefore represents the evaporation amount as shown in equation (3).

The display unit 10 receives the evaporation amount signal S5 from the calculator 9a, and
This is visually displayed as the evaporation amount Gs.

A configuration of a second invention related to this invention is that a reference pressure drop period measurement section is attached in place of the reference pressure rise period measurement section in the configuration of this invention, so that the rising and falling vapor pressure is equal to or lower than the upper and lower limits of vapor pressure. The evaporation amount calculation unit measures the reference pressure drop period required for the pressure to drop from the first set value set in the interval to the second set value set in the same way, and calculates each boiler system determined according to the upper and lower steam pressure limits. Calculate the quotient by dividing the unique first constant by the standard pressure drop period measured by the standard pressure drop period measuring section, and from the quotient, a second constant unique to each boiler system determined according to the heat radiation monitoring of the boiler. The present invention is characterized in that an operation for subtracting is executed, and the result of the operation is output as an evaporation amount signal.

The structure and operation of the second embodiment of the invention related to the present invention will be described below based on FIGS. 5 to 7.

FIG. 1 is a block diagram showing the configuration of an embodiment of the second invention, and in the figure, a reference pressure drop period measurement section 11 has the same structure as the reference pressure rise period measurement section 6 in FIG. One input terminal of the ant gate 11e is connected to the positive phase output terminal of the flip-flop 11c. Furthermore, in the figure,
The evaporation amount calculation section 12 is configured in the same manner as the evaporation amount calculation section 9 in FIG.
A second constant setter 12c is provided.

The other components are the same as those indicated by the same reference numerals in FIG.

The operation of the reference pressure drop period measuring section 11 and the evaporation amount calculating section 12 in the above configuration will be explained with reference to FIG.
It is as follows.

During the heating stop period T2 following the heating period T1, as shown in FIG. 5(A) k, the steam pressure begins to decrease from the upper limit steam pressure H as steam is consumed or the temperature decreases, and in the middle of the heating period T2, as shown in FIG. As shown in (A)u, when the first reference vapor pressure A is reached, the vapor pressure signal S1' becomes smaller than the reference voltage VA, so detecting this, the third converter 7b is activated. (F) Invert the output signal from "1" to "0" as shown in w. This is received as the first reference vapor pressure signal SA' at the set terminal of the flip-flop 11.
c is set to "1", and its positive phase output signal is inverted from "0" to "1" as shown in FIG. 5(J)p.

Furthermore, the vapor pressure decreases, and as shown in Figure 5 (A) ■,
When the second reference vapor pressure B is reached, the vapor pressure signal S1' becomes smaller than the reference vapor pressure Va, so detecting this, the fourth comparator 7c operates as shown in FIG. 5(E)x.
Inverts its output signal from "1" to "0". This is received at the reset terminal as the second reference vapor pressure signal SR', and the flip-flop 11c is reset to "0".
The positive phase output is "1" as shown in Figure 5 (J) t.
to "0".

In this way, the period during which the flip-flop 11c is "1" represents the reference pressure drop period t2.

Subsequently, for example, if the amount of steam (steam load) increases in the process of lowering the steam pressure, there is no amount of heat flowing into the boiler system due to heating of canned water, and furthermore, there is no amount of heat flowing into the boiler system due to the supply of canned water. The amount of heat flowing out from the boiler system due to heat radiation is approximately constant during the heating stop period during steady operation, but the amount of heat flowing out from the boiler system due to evaporation of canned water increases in proportion to the amount of evaporation. As in the case of the step of increasing steam pressure, more heat is removed from the boiler system, and as shown in Fig. 5 (A) k' corresponding to Fig. 3, the downward slope of the vapor pressure becomes steep. It is something that becomes.

Now, hypothetically, at the time shown in FIG. 5(A)g, at the same time, as shown in FIG. 5(D)j, the flip-flop 6b is reversed to "0" and the heating stop period begins. Assuming that, when the amount of evaporation increases, the
and V', the output signal of the flip-flop 11C is inverted as shown in p' and t' in FIG. A reference pressure drop period t2' is formed which is shorter than that.

When the change in the reference pressure drop period t2 that depends on the change in the amount of evaporation is considered in a fixed manner, the amount of evaporation Gs is expressed by the following formula.

However, the standard pressure drop period t20 at Gs=O is, and even if the amount of evaporation (steam load) is zero, the standard pressure drop period t20 is mainly due to the outflow of thermal energy due to heat radiation from the boiler. , is the maximum reference pressure drop period required from the first reference vapor pressure to the second reference vapor pressure.

Then, the reference pressure drop period t expressed by the above equation (5)
FIG. 6 is a graph illustrating the relationship between 2 and the evaporation amount Gs.

In this way, the standard pressure drop period t2 of the boiler system is also specified to a value unique to each boiler system according to the evaporation amount Gs, so if the standard pressure drop period t2 is measured and specified, it can be calculated according to the equation (5) above. It is possible to calculate the amount of evaporation Gs.

That is, during intermittent control of the heating device, the positive phase output signal of the flip-flop 11c becomes "1" during the reference pressure drop period t2, for example, as shown in FIG. 5(J).
In response to such a positive phase output signal, the AND gate 11e opens only during the reference pressure drop period, and the clock pulse from the clock pulse oscillator 11d is guided to the counter 11f for counting.

Then, as shown in FIG. 5(J)t, when the flip-flop 11c is inverted from "1" to "O", the AND gate 11e is closed and the supply of clock pulses to the counter 1f is cut off, and the clock pulse is not supplied to the counter 11f. A digital code representing the reference pressure drop period t2 is generated and output as a reference pressure drop period signal S2'.

At the same time, the arithmetic unit 12a receives the inversion of the positive-phase output signal of the flip-flop 11c from "1" to "0" at the control terminal, and executes arithmetic processing to be described later.

After the arithmetic processing by the arithmetic unit 11a is completed, the monostable multivibrator is triggered and transitioned to a metastable state when the positive phase output signal of the flip-flop 11c is inverted from "1" to "O". 11g returns to a stable state and sends a clear pulse to the clear terminal of counter 1f, so counter 1f is cleared and ready for the next measurement.

During this time, that is, before the counter 1f is cleared, the computing unit 12a sets the first constant CV' preset in the first bag number setting device 12b, which is made of a digital switch or the like.
The quotient is calculated by dividing the first constant signal S3' representing the value by the reference pressure drop period signal S2' outputted by the counter 11f, and then preset in the second constant setting device 12c, which also consists of a digital switch or the like. A second constant signal S4' representing a second constant CR is read in, and this is subtracted from the quotient, and the calculation result is output as an evaporation amount signal S5'.

The evaporation amount signal S5' obtained in this way is the calculation result of , and therefore represents the evaporation amount as shown in equation (5).

The display section 13 receives the evaporation amount signal S5' from the calculator 12a and visually displays it as the evaporation amount G5.

In the configuration of the present invention and the second invention related thereto, the reference pressure increase period measuring section 8 and the reference pressure decrease period measuring section 11 measure the reference pressure increase period t1 and the reference pressure decrease period with respect to one intermittent control. t2 and outputs one reference pressure increase period signal S2 and one reference pressure drop period signal 82', respectively, and calculates the amount of evaporation based on each.However, regarding multiple intermittent control, the reference pressure rising period,
It is also possible to measure the reference pressure drop period, calculate their average value, and process it as one reference pressure increase period signal and one reference pressure drop period signal.

By doing so, it is possible to avoid instantaneous fluctuations in the boiler system, especially variations in the reference pressure rise period signal and reference pressure drop period signal caused by intermittent control of water supply, and to obtain a more stable and accurate amount of evaporation. There is real benefit.

As described above, this invention and the second invention connected thereto measure a reference pressure rise period and a reference pressure drop period and calculate the amount of evaporation based on each of them in a boiler system in which a heating device is controlled intermittently. Therefore, the amount of evaporation in the boiler system can be automatically measured and accurately grasped.

Therefore, according to this invention and the second invention linked thereto, dry heating can be completely prevented by providing backup protection for a control system based on evaporation amount, typically a water supply control system, and also for preventing evaporation. In terms of operational management of the boiler system, securing important basic data has the excellent effect of preventing equipment damage and burnout caused by carryover and scale growth.

[Brief explanation of drawings]

Figure 1 (body) is a block diagram showing the configuration of a small boiler system to which the configuration of the present invention can be attached, Figure 1 (B) is a sectional view taken along line AA of the boiler 1 in Figure 1 (A), figure~
FIG. 4 relates to an embodiment of the present invention, FIG. 2 is a block diagram showing its configuration, and FIG. 3 shows waveforms of main parts of the heating control section 6 and reference pressure rise period measuring section 8 in FIG. 2. FIG. 4 is a graph showing the relationship between the reference pressure increase period t1 and the evaporation amount Gs. 5 to 7 relate to a second embodiment of the present invention, and FIG. 5 shows the heating control section 6 in FIG. 1.
and a waveform diagram of the main parts of the reference pressure drop period measuring section 11, No. 6
The figure is a graph showing the relationship between the reference pressure drop period t2 and the evaporation amount Gs, and FIG. 1 is a block diagram showing the configuration. 1... Boiler 5... First steam pressure detection section 5a... Pressure sensor 5b, 5c...
... Comparator 6 ... Heating control section 7.
...Second vapor pressure detection section 7a...Pressure sensor 7b, 7c...Comparator 8...
...Reference pressure increase period measuring section 9...Evaporation amount calculation section 10...Display section 11...Reference pressure drop period measuring section 12...Evaporation Quantity calculation section 13
...Display section patent applicant Ebara Corporation

Claims (2)

[Claims] (1) A pressure sensor 5a that outputs a steam pressure signal S1 corresponding to the steam pressure of the boiler, and a first comparator 5b that detects that the steam pressure signal S1 is the lower limit setting value and outputs a lower limit steam pressure signal SL. and a second comparator 5c which detects that the vapor pressure signal Sl is the upper limit setting value and outputs the upper limit vapor pressure signal SH.
and intermittent control heating control means 6 that starts the heating device F for heating canned water in response to the lower limit steam pressure signal SL, and stops the heating device F in response to the upper limit steam pressure signal SH.
In the boiler system, a pressure sensor 7a outputs a steam pressure signal S1' corresponding to the steam pressure of the boiler, and a first pressure sensor 7a whose steam pressure signal S1' is set between an upper limit set value and a lower limit set value. A third comparator 7b detects that it is the reference value and outputs the first reference vapor pressure signal SA, and the vapor pressure signal S1' is set between the first reference value and the lower limit set value. a fourth comparator T that detects that the second reference value is the second reference value and outputs the second reference vapor pressure signal S11;
a second vapor pressure detecting means 7 consisting of c, and measuring a reference pressure increase period t1 from when the second reference steam pressure signal SB is output until when the first reference steam pressure signal SA is output. and a reference pressure increase period measuring means 8 that outputs the measurement result as a reference pressure increase period signal S2, and calculates the evaporation lid based on the reference pressure increase period signal S2, and outputs the calculation result as an evaporation amount signal S5. Evaporation amount calculation means 9
The evaporation amount calculation means 3 calculates the quotient Cv/t1 by dividing the constant Cv specific to each boiler system determined according to the upper and lower limit vapor pressure by the reference pressure increase period t1, and calculates the quotient Cv/t1 as the maximum evaporation value. An evaporation amount measuring device in a boiler system, characterized by executing an operation of subtracting from the amount C. (2) A pressure sensor 5a that outputs a steam pressure signal S1 corresponding to the steam pressure of the boiler, and a first comparator 5b that detects that the steam pressure signal S1 is the lower limit set value and outputs a lower limit steam pressure signal SL. and a second comparator 5c which detects that the vapor pressure signal S1 is the upper limit setting value and outputs the upper limit vapor pressure signal 8H, and the lower limit vapor pressure signal SL. In a boiler system equipped with an intermittent control heating control means 6 that starts a heating device F for heating canned water in response, and stops the heating device F in response to an upper limit steam pressure signal SH. a pressure sensor 7a that outputs a vapor pressure signal S1' corresponding to the vapor pressure of
A third comparator 7b detects that the vapor pressure signal S1' is a first reference value set between the upper limit setting value and the lower limit setting value and outputs the first reference vapor pressure signal SA'.
and detects that the vapor pressure signal S1' is a second reference value set between the first reference value and the lower limit setting value, and outputs a second reference vapor pressure signal Sa'. a second vapor pressure detection means T consisting of a fourth comparator 7c; and a reference from when the first reference vapor pressure signal SA' is output to when the second reference vapor pressure signal SB' is output. A reference pressure drop period measurement means 11 measures the pressure drop period t2 and outputs the measurement result as a reference pressure drop period signal S2', and calculates the amount of evaporation based on the reference pressure drop period signal S2'. The evaporation amount calculation means 12 is provided with an evaporation amount calculation means 12 that outputs the calculation result as an evaporation amount signal S5', and the evaporation amount calculation means 12 is based on a first constant Cv' specific to each boiler system determined according to the upper and lower limit steam pressure. The quotient Cv'/t2 is calculated by dividing by the steam pressure stop period t2, and from this quotient, a second constant CR specific to each boiler system is determined according to the heat radiation amount of the boiler.
An evaporation measurement device for a boiler system, characterized in that it performs an operation to subtract .