JPS6333605B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an evaporation amount measuring device for automatically measuring the steam load, that is, the amount of evaporation, in a boiler system, and particularly relates to an evaporation amount measuring device for automatically measuring the steam load, that is, the amount of evaporation, in a boiler system. The present invention relates to an evaporation measuring device that measures evaporation based on both a water supply stop period and a water supply period in intermittent control.

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 carry over and scale growth due to concentration of canned water.

Furthermore, since there are control controls in the boiler system, such as the amount of water supplied, which are controlled to appropriate amounts according to 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, the flow rate is Since the economic burden of equipping a vehicle with a meter is relatively large, it has generally been difficult to adopt it.

Therefore, with conventional small boiler systems, it was not possible to accurately determine the amount of evaporation, so not only was it not possible to provide sufficient backup protection for water supply control systems, etc. The drawback was that there was an extremely high risk of water pipe burnout due to breakage and scale growth.

In view of the problems in boiler system evaporation measurement based on the above-mentioned conventional technology, an object of the present invention is to measure the water supply stop period and water supply period in intermittent control of the water supply control system without using a flow meter, and to It is an object of the present invention to provide an excellent evaporation amount measuring device for a boiler system that can eliminate the above-mentioned drawbacks and automatically measure the evaporation amount by calculating the evaporation amount based on the measurement results.

The configuration of the present invention in accordance with the above object is that a lower limit water level sensor and an upper limit water level sensor are arranged to form a water level detection section, and canned water is supplied to the boiler in response to output signals from each of the upper and lower limit water level sensors. A water supply control unit is provided to start or stop the water supply pump, and when the canned water level drops as steam is consumed and reaches the lower limit water level, the lower limit water level sensor detects this and transmits the lower limit water level signal to the water supply control unit. When the canned water level rises and reaches the upper limit water level with the start of water supply, the upper limit water level sensor detects this and sends an upper limit water level signal to the water supply control unit to start the water supply pump. In a boiler system equipped with an intermittent control water supply control system that stops the water supply, a water supply stop period measurement section and a water supply period measurement section are attached,
The water supply stop period T ₂ from when the water supply pump stops until it starts and the water supply period T ₁ from when the water supply pump starts until it stops are measured, and an evaporation calculation unit is also attached to stop the water supply. Period T ₁ and water supply period T ₂
The evaporation amount G S is calculated based on the following calculation formula, G _S = T ₁ · Q / T ₁ + T ₂ , where Q is a variable and the discharge amount _Q of the water supply pump is a constant. It is something to do.

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

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

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

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

The lower end of the combustion chamber 1e communicates with the flue 1k through the hollow portions of a large number of water pipes 1b. A communicating pipe 1l extends from the upper header 1d to the outside of the wall 1a and connects to the lower header 1.
Connects to c.

A water level gauge 1m and a water level detector 2 for visually displaying the water level of the canned water are installed in the middle of the communication pipe 1l. A water supply control section 3 is connected to the water level detection section 2 , and an output terminal thereof is connected to an electric motor 4 a that drives a water supply pump 4 . An inlet pipe of the water supply pump 4 communicates with a water source (not shown), and a discharge pipe thereof communicates with the lower header 1c.

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

In the configuration of the boiler system described above, when generating steam, the electric motor 1f drives the blower 1g to forcefully feed air into the air passage 1h while applying a high voltage to the electrode rod 1j to generate steam from the tip of the nozzle rod 1i. The injected fuel is ignited and combusted within the combustion chamber 1e. High-temperature combustion gas generated by such combustion enters the hollow part of the water pipe 1b from the lower end of the combustion chamber 1e, passes through it, reaches the flue 1k, and is exhausted.

During this time, heat exchange takes place and the canned water in the water pipe 1b is heated and turned into steam, which is then transferred to the upper header 1d.
The steam is collected and stored at the steam pipe 1q and supplied to the steam load through the steam pipe 1q.

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

When the combustion control unit 6 receives a lower limit steam pressure signal from the pressure detection unit 5 due to continued consumption of steam and the steam pressure in the upper header 1d falls, the combustion control unit 6 connects the control signal line 6 to the lower limit steam pressure signal from the pressure detection unit 5.
Start electric motor 1f through a' and blower 1g
After purging the air passage 1h with air, a high voltage is applied to the electrode rod 1j through the control signal line 6b', and at the same time, a high voltage is applied to the electrode rod 1j through the control signal line 6c'.
d' is started to ignite the fuel injected from the nozzle rod 1i to start combustion, and further, steam generation continues and the steam pressure rises, and an upper limit steam pressure signal is received from the pressure detector 5. Sometimes, the fuel pump 6d' is stopped via the control signal line 6c' to cut off the fuel supply to stop combustion, and the electric motor 1f is stopped via the control signal line 6a' after the fuel gas has been discharged. Cut off air from 1g.

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

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

Furthermore, regarding water supply control, changes in the canned water level in the air-water interface in the communication pipe 1l, that is, in the water pipe 1b, are transmitted to the water level detection section 2, and the water level detection section 2 detects the canned water level set in advance. When it is detected that the lower limit water level has been reached, a lower limit water level signal is sent to the water supply control unit 3, and similarly, when it is detected that the upper limit water level has been reached, an upper limit water level signal is sent to the water supply control unit 3.

When the canned water level in the water pipe drops due to steam consumption and a lower limit water level signal is received from the water level detection unit 2, the water supply control unit 3 starts the electric motor 4a and causes the water supply pump 4 to lower the water pipe through the lower header 1c. 1
When the water supply to b is started, water supply continues, the can water level rises, and an upper limit water level signal is received from the water level detector 2, the electric motor 4a is stopped to cut off the water supply to the water pipe 1b.

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

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

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

Next, the configuration and operation of an embodiment of the present invention will be described below based on FIGS. 2 to 9.

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention. In comparison with the configuration shown in FIG. 1, the water level in the communicating pipe 1l is equal to the can water level in the water pipe 1b.
is replaced with a simple-shaped communication pipe 1l' that is directly supplied with water by the water supply pump 4.

The water level detection unit 2 includes a lower limit water level probe 2 disposed such that its tip is located at the lower limit water level L of canned water.
a, an upper limit water level probe 2b disposed such that its tip is located at the upper limit water level H of canned water, an underwater electrode 2c buried in water, an AC power source 2d whose one end is connected to the underwater electrode 2c, A first current detector 2e inserted between the other end of the AC power source 2d and the lower limit water level probe 2a, and a second current detector inserted between the other end of the AC power source 2d and the lower limit water level probe 2b. It consists of a vessel 2f.

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

The water supply stop period measuring section 7 has a clock pulse oscillator 7a, one input terminal is connected to the output terminal of the clock pulse oscillator 7a, and the other input terminal is connected to the water supply control section 3 (complementary output terminal of the flip-flop 3b). and a counter 7c whose input terminal is connected to the complementary output terminal of the flip-flop 3b, whose output terminal is connected to the clear terminal of the counter 7c. It consists of a connected monostable multivibrator 7d.

The water supply period measuring section 8 includes a clock pulse oscillator 8.
a and one input terminal is the clock pulse oscillator 8.
an AND gate 8b, which is connected to the output terminal of the AND gate 8b and whose other input terminal is connected to the water supply control section 3 (the positive phase output terminal of the flip-flop 3b); and the output terminal of the AND gate 8b is connected to its input terminal. A monostable multivibrator 8d whose input terminal is connected to the positive phase output terminal of the flip-flop 3b and whose output terminal is connected to the clear terminal of the counter 8c.

The evaporation amount production unit 9 includes a microprocessor 9d and a memory 9e, which are interconnected through a data bus 9a, an address bus 9b, and a control bus 9c.
and the first, second and third input ports 9f, 9g, 9h
, and a monostable multi whose complementary output terminals are connected to the output port 9i and the second and third interrupt control lines 9k and 9m among the first, second and third interrupt control lines 9j, 9k and 9m. The input terminals of the second and third input ports 9g and 9h are connected to the output terminals of the counters 7c and 8c, respectively, and the input terminal of the first input port 9f is connected to the keyboard 10a. A data line extending from the constant setting section 10 included therein is connected thereto, and input terminals of the monostable multivibrators 9n and 9p are connected to the positive phase output terminal and the complementary phase output terminal of the flip-flop 6b, respectively.

Note that 11 is a display section connected to the output port 9i.

FIG. 3 shows changes A in the can water level, that is, the water level in the communication pipe 1l', and the changes in the first and second current detectors 2e and 2.
FIG. 3 is a waveform diagram showing a comparison between output signals B and C of the flip-flop 3b and positive phase output signals D and E of the flip-flop 3b.

Water level detection unit 2 and water supply control unit 3 configured as above
Regarding this, the operation of water supply control will be explained as follows.

If the water level is higher than the lower limit water level L as shown in FIG. Since a load circuit consisting of a first current detector 2e, a lower limit water level probe 2a, and an underwater electrode 2c is formed for the AC power supply 2d, a current flows through the first current detector 2e and is detected. The first current detector 2e is shown in FIG.
"1" is output as shown in b.

Then, when the water level falls and reaches the lower limit water level L as shown in FIGS. The current passing through the first current detector 2e becomes zero, and upon detecting this, the first current detector 2e outputs "0" as shown in FIGS. 3C and 3D.

The inverted waveform of the output signal of the first current detector 2e from "1" to "0" is the lower limit water level signal S _L
The flip-flop 3b is connected to the set terminal as
is set to "1", and its positive phase output signal is inverted from "0" to "1" as shown in FIGS. 3D and 3e. In response to this signal, the driver 3c becomes conductive, the relay 3e is excited, the contact 3e' is closed, and power is supplied to the motor 4a, so that canned water is supplied to the boiler.

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

When the water level eventually reaches the upper limit water level H, as shown in Fig. 3A and g, the upper limit water level probe 2b is submerged, and since it has been far from the water surface, , the second current detector 2f, which had been outputting "0", now outputs "1", as shown in FIG. 3B, i.

The inverted waveform of the output signal of the second current detector 2f from "0" to "1" is generated by the inverter 3a.
The waveform is converted from "1" to "0" and sent to the flip-flop 3 as the upper limit water level signal S _H.
B is supplied to the reset terminal of 0 and resets it to ``0''.

As shown in FIGS. 3D and 3J, the positive phase output signal of the flip-flop 3b becomes "0", so the relay 3e becomes de-energized, the contact 3e' opens, and the water supply stops. .

In this way, after the water pump starts,
Period until stopping T ₁ (hereinafter referred to as water supply period)
is specified even during the period when the flip-flop 3b is set to "1", and furthermore, during the period _T2 from when the water supply pump stops to when it starts (hereinafter referred to as the water supply stop period), the flip-flop 3b is set to "0". It is something that can be specified even during a period of time.

During one water supply stop period in the intermittent control of the water supply pump, the water volume V (Kg ), the water supply stop period is specified as a period during which the amount of water V (Kg) is consumed according to the amount of evaporation (Kg/H).

Therefore, the evaporation amount G _S is expressed as G _S =V/T ₂ (1).

Furthermore, since the water volume V is a constant specific to each boiler system that is specified based on the difference G between the upper and lower limit water levels, the evaporation volume G _S is inversely proportional to the water supply stop period. It can be seen that it is proportional to the rate of decline of the water level.

Therefore, after the water supply is stopped, as shown in Fig. 3A, k, the water level will fall again at a rate of decline according to the amount of evaporation, and this will cause the lower limit water level L, as shown in Fig. 3A, l. The flip-flop 3b remains at "0" until it reaches "0", and then is reversed to "1" as shown in FIGS. 3D and 3m, forming a water supply stop period _T2 .

Thereafter, similar operations are repeated until the can water level is maintained between the upper limit water level H and the lower limit water level L.

For example, qualitatively considering the change tendency of the water supply stop period T ₂ corresponding to an increase in the amount of evaporation G _S is as follows.

As shown in Figure 3 A, k', the rate of decline of the water level increases, and at the same time, at the time shown in Figure 3 A, g, the water supply is stopped as shown in Figure 3 E, j'. Assuming that the water supply stop period T 2 is reached, the flip-flop 3b will be inverted to "1" as shown in FIG. 3 E, m' at the time shown in FIG. 3 A, l', so that the water supply stop period T ₂ A shorter water supply stop period T ₂ ' is formed.

Water supply cutoff period that varies depending on the amount of evaporation
FIG. 4 is a graph illustrating the general change tendency of T ₂ , that is, the functional relationship of equation (1) above.

As is clear from the figure, in the region where the water supply cutoff period T ₂ is small, in other words, in the region where the evaporation amount is large, the increase or decrease in the evaporation amount corresponding to the increase or decrease in the unit amount of the water supply cutoff period T ₂ becomes extremely large. The slope of the curve tends to become steeper.

Next, the operation of the water supply stop period measuring section 7 will be explained as follows.

During the intermittent control of the water supply pump, the positive phase output signal of the flip-flop 3b becomes "0" during the water supply stop period _T2 , for example, as shown in FIG. It becomes "1" during T ₂ . In response to this complementary output signal, the AND gate 7b opens only during the water supply stop period, and the clock pulse from the clock pulse oscillator 7a is guided to the counter 7c to be counted.

Then, as shown in FIG. 3D and m, when the flip-flop 3b is reversed from "0" to "1",
The complementary output signal is inverted from "1" to "0",
The AND gate 7b closes and the supply of clock pulses to the counter 7c is cut off.
A digital code representing the water supply suspension period _T2 is generated and output as the water supply suspension period signal _S1 .

After that, when the complementary output signal of the flip-flop 3b is inverted from "1" to "0", the monostable multivibrator 7d, which was triggered and had transitioned to a metastable state, returns to a stable state and issues a clear pulse. Since the signal is sent to the clear terminal of the counter 7c, the counter 7c is cleared and prepared for the next measurement.

Next, regarding the water supply period in intermittent control of the water supply pump, the amount of water V accumulated in the boiler during one water supply period is determined based on the difference G between the lower limit water level L and the upper limit water level H, and the cross-sectional area of the water pipes between them. The amount of water V is determined by the balance between the amount of water flowing into the boiler, that is, the discharge amount of the water pump 4, and the amount of water flowing out from the boiler, that is, the amount of evaporation. FIG. 5 is an explanatory diagram showing this.

With reference to the same figure, for one water supply period T ₁ ,
Considering the amount of inflow and outflow to the boiler, canned water flows in with the discharge amount Q [Kg/H] specific to the water supply pump, and is converted into steam and flows out with the evaporation amount G _S [Kg/H]. In such a state, that is, in a state in which canned water is accumulated even with the difference in inflow and outflow (Q - G _S ) [Kg/H], one water supply period
It can be seen that when T ₁ has passed, an amount of water V [Kg] has been accumulated in the boiler.

Therefore, the amount of water V is expressed as V=T ₁ (Q-G _S ), so if we calculate the amount of evaporation G _S from the above equation, we get G _S = Q-V/T ₁ ...(2) .

Here, the discharge amount Q and the water supply amount V are constants specific to each boiler system, so if the water supply period _T1 is measured and determined, the evaporation amount G _S can be calculated according to the above formula. It is something.

Referring to FIG. 6, which corresponds to FIG. 3, if we qualitatively consider, for example, the tendency of change in the water supply period _T1 corresponding to an increase in the amount of evaporation G _S , it will be as follows.

As shown in Fig. 6 A and f', the rate of rise in the water level decreases, in other words, the difference between the discharge amount Q and the evaporation amount G _S (Q - G _S ) decreases, and now, as shown in Fig. 6 Assuming that at the time points shown in A and c, the water supply period has simultaneously entered as shown in FIG. 6 E and e', then at the time points shown in FIG. 6 A and g' As shown,
Since the flip-flop 3b is inverted to "0", the water supply period is longer than the water supply period _T1 .
T ₁ ' is formed.

The water supply period T ₁ varies depending on the amount of evaporation
FIG. 7 is a graph illustrating the general change tendency of , that is, the functional relationship of equation (2) above.

As is clear from the figure, in the region where the water supply period T ₁ is small, in other words, in the region where the amount of evaporation is small,
The increase or decrease in the amount of evaporation corresponding to the increase or decrease in the unit amount during the water supply period _T1 becomes extremely large, and the slope of the curve tends to become steeper.

It should be noted that the discharge amount Q is generally set to be much larger than the evaporation amount G _S in the full load state, so even in the full load state, the water volume V at one time is secured and the water supply system There is no problem with intermittent control.

Next, the operation of the water supply period measuring section 8 will be explained as follows.

During intermittent control of the water supply pump, the positive phase output signal of the flip-flop 3b becomes "1" during the water supply period _T1 , for example, as shown in FIG. 6D. Upon receiving such a positive phase output signal, only during the water supply period,
AND gate 8b opens and directs the clock pulse from clock pulse oscillator 7a to counter 8c for counting.

Then, as shown in FIG. 6D and j, when the flip-flop 3b is inverted from "1" to "0",
The positive phase output signal is inverted from "1" to "0",
The AND gate 8b closes and the supply of clock pulses to the counter 8c is cut off.
A digital code representing the water supply period T ₁ is generated,
It is output as the water supply period signal _S2 .

After that, when the positive phase output signal of the flip-flop 3b is reversed from "1" to "0", the monostable multivibrator 8d, which was triggered and had shifted to a quasi-stable state, returns to a stable state and issues a clear pulse. Since the signal is sent to the clear terminal of the counter 8c, the counter 7c is cleared and prepared for the next measurement.

By the way, the above-mentioned evaporation amount G _S , water supply stop period T ₂ ,
Regarding the correlation of the water supply period T ₁ , if we calculate the water volume V from equation (1) and substitute it into equation (2) to eliminate the water volume V, we get G _S = T ₁・Q/T ₁ + T ₂ ... …(3) The following relational expression is obtained.

Thus, if the water supply stop period T ₂ and the water supply period T ₁ are measured and specified, the evaporation amount G _S can be calculated according to the above equation (3).

Then, based on equation (3), the ratio of the water supply period T ₁ to the sum of the water supply period T ₁ and the water supply stop period T ₂
The relationship between T ₁ /T ₁ +T ₂ and the amount of evaporation G _S is illustrated in a graph as shown in Fig. 8. Since the amount of evaporation G _S changes linearly with respect to T ₁ /T ₁ + T ₂ , As in the graphs illustrated in FIGS. 4 and 7, the water supply period T ₁ ,
In the region where the water supply stop period T ₂ is small, the evaporation amount G _S does not have a steep gradient and over the entire change range of T ₁ /T ₁ + T ₂ , that is, the entire change range of the evaporation amount.
The rate of change of is equalized.

Additionally, regarding the graph in Figure 8, the straight line A when the pump discharge amount is large (when Q is large) is higher than the straight line B when the pump discharge amount is small (when Q is small). To position.

Next, the operations of the evaporation amount calculating section 9, the constant setting section 10, and the display section 11 will be explained with reference to FIGS. 2, 3, 6, and 9.

FIG. 9 is a flowchart of calculation processing in the evaporation amount calculation section 9.

First, when the evaporation amount calculation unit 9 starts operating, the microprocessor 9d executes the process shown in FIG. After making sure that the water supply period T ₁ and water supply stop period T ₂ are not read before the constant Q is set, proceed to the process shown in Fig. 9b and execute the interrupt processing to set the constant Q. In order to do so, it waits for an interrupt.

When the operator operates the keyboard 10a of the constant setting section 10 and performs a key operation to start the constant setting process, the first interrupt control line 9j becomes "0" and the microprocessor 9d A first interrupt command signal is provided. Then, the microprocessor 9d shifts to the step shown in FIG. 9c, and by prohibiting interrupt processing other than the first interrupt processing, the water supply period T is ₁ ,
Make sure not to read the water supply stop period T ₂ , and then
The process moves to the step shown in FIG. 9d.

Then, an address signal specifying the first input port 9f is sent to the address bus 9d, a control signal is sent to the control bus 9c, and a constant signal S is supplied from the constant setting section 10 to the first input port 9f. Load ₃ . The constant signal _S3 is a digital code generated by key operations for constant setting on the keyboard 10a, and represents the constant Q. At this time, the constant signal _S3 read from the first input board 9f is transferred to the microprocessor 9d via the data bus 9a and stored in the first register within the microprocessor 9d.

After that, the process moves to the step shown in FIG. 9e, and after canceling the prohibition of the interrupt processing executed in the step shown in FIG. 9c, the process returns to the step shown in FIG. 9b through the return step shown in FIG. , the water supply period T ₁ , and the water supply stop period T ₂ .

When the intermittent control of the water supply device is performed under such conditions, as already explained, the digital code _S2 representing the water supply period _T1 is output from the counter 8c, and at the same time, the positive phase output signal of the flip-flop 3b is changed to "1". ” to “0”, the monostable multivibrator 9n is triggered and shifts to a quasi-stable state, and the second interrupt control line 9k is set to “0”.
A second interrupt command signal is given to the microprocessor 9d.

The microprocessor 9d that has received the second interrupt command signal executes the process shown in FIG.
c, the water supply period signal _S2 representing the water supply period _T1 outputted by the counter 8c is read from the input port 9g, and in the process shown in FIG. 9d and stored in the second register.

Thereafter, the process returns to the step of FIG. 9b through the return step of FIG. 9i, and waits for an interrupt in order to read the water supply stop period _T2 following the water supply period _T1 .

When one water supply period _T1 ends, the counter 7c outputs the water supply stop period signal _S1 representing the water supply stop period _T2 , and at the same time, the monostable multivibrator 9p is triggered and shifts to a quasi-stable state, The third interrupt control line 9m is set to "0" and a third interrupt command signal is given to the microprocessor 9d.

The microprocessor 9d that has received the third interrupt command signal then executes the process shown in _{FIG .} In the process shown in FIG. 9k, this is transferred and stored in the third register in the microprocessor 9d, and then in the process shown in FIG.
Proceed to the process shown in Figure 1.

In the step of FIG. 9l, the content of the first register stored in the step d is multiplied by the content of the second register stored in the step h to calculate the product;
Furthermore, by adding the contents of the third register stored in step k to the contents of the second register to calculate the sum, and calculating the quotient by dividing the above product by the above sum, T ₁ · The calculation Q/T ₁ +T ₂ is executed and the calculation result is stored in the fourth register.

The result of this calculation represents the evaporation amount G _S as shown in equation (3).

Next, the microprocessor 9d moves to the step shown in FIG. 9m, outputs the contents of the fourth register as the evaporation amount signal _S4 through the output port 9i, and
In the return step shown in FIG. 9n, the process returns to the step shown in FIG. 9b, and enters a state of waiting for an interrupt, waiting for the next measurement, that is, to receive the second interrupt command signal.

The display unit 11 receives the evaporation amount signal _S4 and displays it visually.

Note that the memory 9e is for storing a program for the series of arithmetic operations described above, and each step of the program is sequentially read out from the memory 9e, transferred to the microprocessor 9d, decoded, and stored in the series of operations described above. The calculation process is executed.

In the above configuration of the present invention, the water supply period measurement section 8 and the water supply stop period measurement section 7 measure the water supply period T ₁ and the water supply stop period T ₂ for one intermittent control, and
One water supply period signal S ₂ and one water supply stop period signal S ₁ are output, respectively, and the evaporation amount is calculated based on each, but the water supply period and water supply stop period are measured for multiple intermittent controls. , these average values can be calculated and processed as one water supply period signal and one water supply stop period signal.

By doing so, it is possible to avoid instantaneous fluctuations in the boiler system, especially variations in the water supply control signal and water supply stop period signal caused by intermittent control of water supply, and there is the practical benefit of obtaining a more stable and accurate amount of evaporation. .

Further, the water supply period measuring section 8 and the water supply stop period measuring section 7 are configured to operate in response to the "1" and "0" states of the flip-flop 3b of the water supply control section 3, but the present invention is not limited to this. Rather, it is sufficient to measure the period from the time the water supply device starts until it stops, or from the time the water supply device stops until it starts, so it is sufficient to start and start the water supply device as described above. It may be configured to directly respond to the signal for stopping, that is, the "1" or "0" state of the flip-flop 3b, or the operating state of the water supply device as a result of being controlled based on that signal. For example, a configuration may be adopted in which the water supply period and the water supply stop period are measured in response to the intermittent state of the water supply pump 4, the intermittent state of rotation of the electric motor 4a, and the like.

In addition, in the above embodiment, the upper and lower limit water level probe 2
Using the conductivity between b, 2a and the underwater electrode 2c,
Although the water level is detected, it is not limited to this, and instead of the configuration of the upper and lower limit water level probes 2b, 2a, etc., an optical system consisting of a light emitting element and a light receiving element arranged opposite each other at positions corresponding to the upper and lower limit water levels. water level sensor,
It is optional to employ an upper and lower limit water level sensor including a magnetic water level sensor that detects a magnetic float with a magnetic sensor disposed at a position corresponding to the upper and lower limit water levels. Alternatively, a configuration may be adopted in which a water pressure signal proportional to the can water level is obtained from a single pressure sensor, and a comparator detects when this signal reaches the upper and lower limit set values.

As in the above configuration, it is possible to realize the upper and lower limit water level sensors in one piece using only one piece of hardware, so the lower limit water level sensor and upper limit water level sensor referred to in this specification are not necessarily realized as separate and independent hardware. It is not limited to the configuration.

As described above, the present invention is configured to measure the water supply period and the water supply stop period and calculate the evaporation amount based on both of the water supply period and the water supply stop period in the boiler system that performs intermittent control of the water supply device. The amount of evaporation can be automatically measured and accurately grasped.

Therefore, according to the present invention, 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 it is possible to completely prevent boiler system operation management based on evaporation amount. Additionally, by securing important basic data, damage to equipment, etc. due to carry over and scale growth,
It has the excellent effect of preventing burnout.

Further, according to the present invention, the water supply period T ₁ and the water supply stop period T ₂ are variables, and based on the following calculation formula that depends on T ₁ /T ₁ +T ₂ , G _S =T ₁ ·Q / T ₁ +T ₂ By configuring the system to calculate the amount of evaporation G _S , it is possible to determine that the amount of evaporation G _S depends approximately linearly on T ₁ /T ₁ + T ₂ as shown in the graph of FIG. Therefore, the water supply period T ₁ and the water supply suspension period T ₂
In other words, it is possible to equalize the rate of change in the amount of evaporation with respect to changes in the water supply period T ₁ and the water supply stop period T ₂ over _the entire range of change in the amount of evaporation. Or the water supply suspension period
A sudden change in the amount of evaporation that cannot be avoided by calculation processing based on either T ₂ , that is, in a region where the water supply period T ₁ and the water supply stop period T ₂ are small, as shown in the graphs of FIGS. 4 and 7. , the tendency of extremely large increases and decreases in _the amount of evaporation with respect to increases and decreases in the unit amount during the water supply period T ₁ and the water supply suspension period T 2 is eliminated, and as a result, the tendency of extremely large increases and decreases in the amount of evaporation caused by the quantization error when measuring the water supply period T ₁ and the water supply suspension period T ₂ is eliminated. Since the error in the amount of evaporation that occurs is equalized over the entire range of changes in the amount of evaporation, it is possible to measure the amount of evaporation with approximately uniform accuracy over the entire range of changes in the amount of evaporation, which in turn realizes highly accurate measurement. It also has the excellent effect of being able to do so.

Furthermore, the water level detection section and the water supply control section in the configuration of this invention are essential components for intermittent control of water supply, and these can be used as they are to start and start the water supply pump obtained from the water supply control section.
Since it is sufficient to add a configuration for processing the stop signal, there is an advantage that the configuration is simple and wasteful, and can be realized at low cost.

[Brief explanation of the drawing]

Figure 1A is a block diagram showing the configuration of a small boiler system to which the configuration of the present invention can be attached.
Figure B is a sectional view taken along the line AA of the boiler 1 in Figure 1A, Figures 2 to 9 relate to embodiments of the present invention, Figure 2 is a block diagram showing its configuration, Figure 3, Fig. 6 is a waveform diagram of the main part of the water supply control unit 3 in Fig. 2, Fig. 4 is a graph showing the relationship between water supply stop period T ₂ and evaporation amount G _S , and Fig. 5 is a graph showing the relationship between water supply period T ₁ and evaporation amount. An explanatory diagram showing the relationship between G _S , Figure 7 is a graph showing the relationship between water supply period T ₁ and evaporation amount,
The diagram shows water supply period T ₁ , water supply period T ₁ and water supply stop period.
FIG. 9 is a graph showing the relationship between the ratio of T ₂ to the sum and the evaporation amount G _S , and FIG. 9 is a flowchart showing the calculation processing in the evaporation amount calculating section 9 in FIG. 2...Water level detection unit, 2a...Lower limit water level probe, 2b...Upper limit water level probe, 3...Water supply control unit, 4...Water supply pump, 7...Water supply stop period measurement unit, 8...Water supply period measurement unit , 9... Evaporation amount calculation section, 10... Constant setting section, 11... Display section.

Claims (1)

[Claims] 1. Detecting that the can water level is the lower limit water level,
a lower limit water level sensor 2a that outputs a lower limit water level signal S _L ;
2e, and upper limit water level sensors 2b and 2f which detect that the can water level is an upper limit water level above the lower limit water level and output an upper limit water level signal S _H ; and a lower limit water level signal S _L In a boiler system equipped with an intermittent control water supply control means 3 that starts a water supply pump that supplies canned water to the boiler in response to an upper limit water level signal S _H and stops the water supply pump in response to an upper limit water level signal SH, the water supply pump is stopped. water supply stop period measuring means 7 that measures the period from when the water supply pump starts until it starts, and outputs a water supply stop period signal _S1 representing the measurement result; and a water supply period signal representing the measurement result.
A water supply period measuring means 8 that outputs _S2 , a water supply stop period T2 represented by a water supply stop period signal _{S1 ,} and a water supply period _T1 represented by a water supply period signal _S2 as variables, and a discharge amount Q of the water supply pump 4. An evaporation amount calculation output stage 9 that calculates the evaporation amount G _S based on the following calculation formula, G _S = T ₁ · Q / T ₁ + T ₂ , where is a constant, and outputs an evaporation amount signal S ₄ representing the calculation result.
An evaporation measurement device for a boiler system, which is equipped with: