JPS6323811B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides for a plurality of processing devices having approximately the same shape inserted in parallel between a main inflow path and a main outflow path where the flow rate changes, to reduce the critical clogging state of each processing device. The present invention relates to a clogging state detection method for detecting a clogging state.

For example, various treatment devices such as condensate desalination devices, ion exchange devices, and electromagnetic filter devices are used in condensate treatment systems of nuclear and thermal power plants. In these processing devices, a plurality of devices of the same model with approximately equal capacity are inserted in parallel between the main inflow path and the main outlet path, and each reaches its limit clogging with a time difference. It is operated continuously by replacing the processing equipment with one that has been successively regenerated.

In general, for each superconductor in a system with multiple superconductors in parallel, where the entire system is operated at a constant flow rate,
To detect clogging, it is possible to use the increase in head loss △P in each excess vessel, and therefore the decrease in the flow rate of the said excess vessel, as a guideline. It is possible to estimate whether the The treatment equipment in the condensate purification system of the power plant mentioned above is no exception, and the same type of equipment with some improvements is used to detect clogging in individual treatment equipment.

However, in recent years, nuclear and thermal power plants have adopted computers for operational management, making it easier to control the amount of power generated in response to ever-changing power demand. As well, the amount of power generated has come to be adjusted during operation, and as a result, the flow rate of condensate is no longer constant, but fluctuates from moment to moment.

By the way, as mentioned above, when the flow rate of the condensate treatment system is not constant, even if an increase in the head loss △P or a decrease in the flow rate is detected for each individual treatment device, it is not possible to determine whether the treatment device is at the limit of clogging. It cannot be used as a guideline for whether or not it is true. For example, even if you know the water head loss that indicates the critical clogging state for one treatment device when the flow rate is constant, when the flow rate of the entire system decreases, the head loss of the treatment device will decrease accordingly. Therefore, even though the processing device is in a critical clogging state, it does not necessarily issue a danger signal. In order to cope with such a situation, there is a need for a method for more reliably detecting the presence or absence of a critical clogging state in each processing device even if the flow rate of the entire system fluctuates.

The present invention was developed in response to the above requirements, and includes a plurality of treatment devices having approximately the same shape inserted in parallel between the main inflow path and the main outflow path of a condensate treatment system where the flow rate changes. A differential pressure gauge measures the differential pressure between the main inflow channel and the main stream outlet channel, multiple flow meters measure the flow rate of each processing device individually, and the differential pressure △P between the main inlet channel and the main stream outlet channel reaches the limit clogging. The relational expression between the flow rate Q of one processing device and the time △P=AQ ² +
A calculation device that stores BQ+C (A, B, and C are constants) is provided, and the minimum allowable flow rate is calculated from the differential pressure between the main inflow passage and the main output passage shown on the differential pressure gauge using the above relational expression. Provided is a clogging state detection method for a condensate treatment device, characterized in that the presence or absence of a critical clogging state in each treatment device is detected by comparing the flow rate with the flow rate appearing on the individual flowmeters. It is.

As shown in FIG. 1 below, the main inflow path is the inlet side condensate main pipe 5 that connects to the condensate discharge pipe of the water use device (not shown), and the main outlet path is the condensate supply booster pump to the water use device. In the condensate treatment system, which is the outlet side condensate main pipe 6 connected to the main pipe (not shown), four passing water towers 1 to 4 are connected in parallel as a condensate treatment device between the main pipes 5 and 6. Regarding the processing system,
The clogging detection principle of the present invention will be explained.

In Fig. 1, a differential pressure gauge 7 is installed between the main pipes 5 and 6 to measure the differential pressure between the two pipes. The differential pressure is measured and the differential pressure ΔP is transmitted. Furthermore, the water towers 1 to 4 are of the same model with approximately equal capacity, and flow meters 11 to 14 are provided on the discharge side connected to the main pipe 6, respectively, to measure the flow rate individually, and the flow rate Q Send ₁ to Q ₄ .

Reference numeral 8 in FIG. 1 is an arithmetic unit that stores the ΔP-Q characteristic diagram for one water tower in the critical clogging state. Compute the corresponding minimum allowable flow rate Q _s . Further, 9 is a comparator that compares the flow rate Q _s calculated by the arithmetic unit 8 with the flow rate values Q ₁ to Q ₄ from the flow meters 11 to 14, and thereby determines the clogging state of each water tower. It transmits a judgment signal.

Water towers 1 to 4 have different elapsed water flow operation times so that they do not reach the limit of clogging at the same time, so the degree of clogging of each tower is different, and all of water towers 1 to 4 It has a ΔP-Q characteristic that corresponds to a unique clogging situation. As an example, △P-Q for each tower in Figure 1
As shown in the characteristic diagram, the curve of tower 4 is the steepest, and it is presumed that it is in a critical clogging state. Also, the curve of tower 3 is the most curved,
It is presumed that it has just been regenerated. By the way, now, a ΔP-Q characteristic diagram curve corresponding to the critical clogging state of the tower is stored in the calculator 8, and on the other hand, between the main condensate pipe 5 on the inlet side and the condensate main pipe 6 on the outlet side, The differential pressure ΔP is measured by the differential pressure gauge 7, and the reference minimum allowable flow rate Q _s corresponding to the measured ΔP is calculated from the above-mentioned stored curve. Then, compare this flow rate Q _s with each individual flow rate Q ₁ to Q ₄ ,
If any of the flow rates _Q1 to _Q4 is smaller than the minimum allowable flow rate _Qs , it is determined that the water tower is in a critical clogging state.

The above-mentioned limit clogging state curve is expressed by the approximate formula △P=AQ ² +BQ+C (where △P is the differential pressure between the main pipes, Q is the flow rate, and A, B, and C are all constants)
It is assumed that the curve is stored in the arithmetic device. Note that the constants A, B, and C are calculated as follows.

Now, as a specific example, the maximum design differential pressure between the main pipes is 3.9, which indicates a critical clogging condition at a rated flow rate of 683 mm ³ /H.
When the curve of ΔP-Q is actually measured for one water tower of a mixed-bed condensate desalination device of kg/cm ² , it is expressed as shown by the thick solid line in FIGS. 2 to 4. By the way, the head loss of a pipe can be approximated by a formula such as the Darcy-Weisbach formula, which is the square of the flow rate multiplied by a coefficient.

△P=k・Q ² k: Coefficient Q: Flow rate However, as shown by the dotted line and chain line in Figure 2, this equation causes a considerable error between the actual measurement value and the curve that should be stored in the calculation device. is inappropriate. The next possibility is to modify the index as shown in the following formula.

ΔP=k·Q ⁿ k,n: Coefficient Q: Flow rate Although this approximates more than the above-mentioned Darcy-Weisbach equation, the error still remains as shown in FIG.

In the present invention, the following quadratic equation was tried as the equation that could be most approximated.

△P=AQ ² +BQ+C A:B:C Coefficients Coefficients A, B, and C represent the flow rate of Q, 2Q, and 3Q.
Take the point and calculate the corresponding pressure difference in the main tube as △P ₁ ,
When △P ₂ and △P ₃ , △P ₁ = AQ ² +BQ+C △P ₂ = 4AQ ² +2BQ+C △P ₃ = 9AQ ² +3BQ+C Since the following three equations hold true, solve this simultaneous equation and get A=△ It can be obtained as P ₃ −2ΔP ₂ +ΔP ₁ /2Q ² B=ΔP ₂ −ΔP ₁ −3AQ ² /Q C=ΔP ₁ −AQ ² −BQ. In other words, from the measured curve in Figure 4, △P ₁ (at 200m ³ /H) 0.57Kg/cm ² △P ₂ (at 400m ³ /H) 1.53Kg/cm ² △P ₃ (at 600m ³ /H) ) 3.07Kg/cm ² , so by substituting it into the above formula, A=7.25×10 ^-6 B=4.5×10 ^-4 C=0.19, and the coefficient values are determined.

So △P=7.25×10 ^-6 Q ² +4.5×10 ^-4 Q+0.19
The equation is shown as a chain line curve in FIG. 4, and it can be seen that the calculated curve closely approximates the measured curve in the region where ΔP is 0.4 Kg/cm ² or more. As can be seen from Figure 4, a certain amount of error occurs in the region where ΔP is 0.4Kg/cm ² or less, but in this region the differential pressure shows a high value relative to the flow rate, so Since the calculation curve is on the safe side, there is no problem in practice.

Note that the values of coefficients A, B, and C vary depending on the type of condensate water treatment equipment and the size of the condensate treatment equipment even if the same type of condensate treatment equipment is used. Measure the curve of △P-Q using this method, and find coefficients A, B, C that approximate the measured value.
shall be determined respectively.

The apparatus used to carry out the invention is shown in block diagram form in FIG. In Fig. 5, condensate flows from the inlet main pipe 5 to the passing water tower 1 as shown by the arrow.
4, passes through each, and flows to the outlet side main pipe 6, but at this time, the differential pressure between the main pipes 5 and 6 is
P is measured by a differential pressure gauge 7, and the signal of the differential pressure △P is input to an arithmetic unit 8 having a quadratic circuit of △P=AQ ² +BQ+C to perform calculations and calculate the allowable minimum flow rate Q _s is determined and the signal is output. On the other hand, flow meters 11 to 14 are disposed on the outlet side of each water tower 1 to 4, respectively, and these flow meters transmit signals of flow rates Q ₁ to Q ₄ for each water tower.

The allowable minimum flow rate Q _s and the flow rates Q ₁ to Q ₄ are input to comparators 9 ₁ to 9 ₄ and compared, and if Q _s >Q ₁ to Q ₄ , an alarm is issued from the comparators 9 ₁ to 9 ₄ . A signal is transmitted and the corresponding alarm indicator lights 15 ₁ to 15 ₄ are lit to warn that the corresponding water tower is in the critical clogging state.

In addition, in order to prevent excessive flow of water from flowing through any of the water towers for some reason, the signals of the flow rates Q ₁ to Q ₄ from the flow meters 11 to 14 are set by the maximum flow rate setting device 17. maximum flow rate
Q _nax is input to the comparators 10 ₁ to 10 ₄ to compare the two, and when the flow rates Q ₁ to Q ₄ exceed the flow rate Q _nax , an alarm signal is sent from the comparators 10 ₁ to 10 ₄ and a countermeasure is taken. The warning indicator lights 16 ₁ to 16 ₄ can be turned on to warn that the water tower in question is flowing water at a flow rate higher than the maximum set flow rate.

Remembering the quadratic formula △P=AQ ² +BQ+C,
Regarding the calculation device that calculates the allowable minimum flow rate Q _s from the pressure difference between the main pipes of the condensate treatment system, both analog and digital methods are possible, but digital is more advantageous in terms of accuracy and cost. It is.

As is clear from the above description, according to the present invention, one differential pressure gauge is provided between the main inlet and the main outlet of the condensate treatment system where the flow rate changes, and the main inlet and the main outlet are A flow meter is installed in each of the plurality of processing devices inserted in parallel between the Since the clogging state can be detected reliably, the effect is extremely large when operating the condensate treatment system.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the clogging detection principle of the condensate treatment equipment according to the present invention, Fig. 2 is a △P-Q characteristic diagram shown by the formula △P = k・Q ² , and Fig. 3 is a diagram of the formula △ P
=k・Q ⁿ , FIG. 4 is a ΔP-Q characteristic diagram shown by the formula ΔP=AQ ² +BQ+C in the present invention, and FIG. 5 is a ΔP-Q characteristic diagram in the present invention. FIG. 2 is a block diagram of the apparatus for implementation. 1, 2, 3, 4... Passing water tower, 5... Inlet side condensate main pipe, 6... Outlet side condensate main pipe, 7... Differential pressure gauge, 8... Arithmetic device, 9 ₁ , 9 ₂ , 9 ₃ , 9 ₄ ... comparator, 10 ₁ , 10 ₂ , 10 ₃ , 10 ₄ ... comparator,
11, 12, 13, 14...flow meter, 15 ₁ , 1
5 ₂ , 15 ₃ , 15 ₄ ... Alarm indicator light (low flow rate), 1
6 ₁ , 16 ₂ , 16 ₃ , 16 ₄ ... Alarm indicator light (high flow rate), 17 ... Maximum flow rate setting device.

Claims (1)

[Claims] 1 A difference in measuring the differential pressure between the main inlet and the main outlet in a plurality of treatment devices of approximately the same shape inserted in parallel between the main inlet and the main outlet in a condensate treatment system where the flow rate changes. A pressure gauge, a plurality of flowmeters that measure the flow rate of each processing device individually, a relational expression △ between the differential pressure △P between the main inflow path and the main outlet path, and the flow rate Q of one processing device when the limit clogging is reached. P= ^AQ2 +
A calculation device that stores BQ+C (A, B, and C are constants) is provided, and the allowable minimum flow rate is calculated from the differential pressure between the main inflow passage and the main output passage shown on the differential pressure gauge using the above relational expression. 1. A method for detecting a clogging state of a processing device, characterized in that the presence or absence of a critical clogging state in each processing device is detected by comparing the flow rate with the flow rate appearing on each flowmeter.