JP2008064064A - Pumping installation and operating method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pumping installation and the operating method thereof capable of appropriately controlling the quantity of flow of a pump for taking-in seawater through a dust collector provided in a sea area. <P>SOLUTION: This pumping installation 1 installed on a waterway for taking-in seawater 23 through the dust catcher 20 provided in the sea area for catching dust 30 to pass the seawater 23 through includes: a pump tank 2 for communicating with the waterway; a pump 4 of which a suction opening 3 is inserted into the pump tank 2; a pump tank water level measuring device for measuring a water level of the pump tank 2; a pump tank water level change rate calculating device 11 for calculating a change rate in the water level of the pump tank 2 from the water level of the pump tank 2 measured by the pump tank water level measuring device; and a pump flow rate control device 12 for controlling a flow rate of the pump 4 according to the water level of the pump tank 2 and the change rate in the water level of the pump tank 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pump device that takes in seawater through a dust remover installed in a sea area and a method for operating the pump device.

  A thermal power plant or the like is equipped with a condenser for cooling steam generated by a boiler, and seawater is used as cooling water for the condenser. In the water channel through which the condenser takes in the cooling water, a dust remover is provided to prevent the collection of dust such as jellyfish in the condenser (for example, see Patent Document 1), and passes through the dust remover. The collected seawater is taken in by a pump device and supplied to the condenser.

  There are various types of dust removers depending on the type of dust trapping method, and one of them is a net type dust remover. The net-type dust remover has a portion (screen) that captures dust in a mesh shape (for example, a wire mesh). The lower part of the screen is placed in the water channel, and the upper part is placed in the sea so that the upper part is exposed on the water channel. The And when dusts, such as a jellyfish, flow into a water channel, since dust adheres to a screen, it has the structure where dust does not flow to the downstream of a screen.

  When the dust adhering to the screen increases, the flow of water passing through the screen is hindered, the amount of water flowing downstream decreases, and the water level downstream of the dust remover decreases, but if the water level becomes too low, the pump removes seawater. It becomes impossible to suck in and cooling water cannot be supplied to the condenser. In order to prevent such a situation and continuously supply cooling water to the condenser, the flow rate (water intake amount) of the pump must be reduced in advance.

  Here, when dust adheres to the screen, a water level difference occurs between the upstream side and the downstream side of the screen, so conventionally, the water level before and after the dust remover is measured and the pump flow rate is based on this water level difference. Was decreasing.

  However, even if the water level difference before and after the dust remover is the same, the operation limit point at which the pump can continue to operate varies depending on the tide level and the pump flow rate. Therefore, in the method of controlling the flow rate of the pump based only on the difference between the water levels before and after the dust remover, it is impossible to determine an appropriate timing or amount for reducing the flow rate of the pump, and the pump flow rate cannot be appropriately controlled.

JP 2001-64946 A

  In view of such circumstances, an object of the present invention is to provide a pump device that can appropriately control the flow rate of a pump that takes in seawater through a dust remover installed in a sea area, and an operation method of the pump device.

  In order to achieve the above object, a first aspect of the present invention is a pump device provided in a water channel that is installed in a sea area and captures the dust through a dust remover that passes the sea water and passes the sea water. A pump, a pump having a suction port inserted in the pump tank, a pump tank water level measuring means for measuring the water level of the pump tank, and the pump tank water level measured by the pump tank water level measuring means. Pump tank water level change rate calculating means for calculating a water level change rate, and pump flow rate control means for controlling the flow rate of the pump in accordance with the water level of the pump tank and the water level change rate of the pump tank. It is in the pump device.

  In such a first aspect, the pump device has a pump tank water level measuring means and a pump tank water level change rate calculating means, and according to the pump tank water level and the pump tank water level change rate measured and calculated by these means. Since the flow rate of the pump is controlled, it is possible to control the flow rate of the pump appropriately considering the influence of the tide level and the like. Therefore, seawater can be continuously taken in by the pump, and the flow rate of the pump can be increased as much as possible.

  According to a second aspect of the present invention, in the pump device according to the first aspect, the water discharged from the pump is used as cooling water for a condenser of a power plant.

  In the second aspect, the pump device that can continuously take in a large amount of seawater without stopping the pump is used as the cooling water supply means of the condenser of the power plant, thereby continuously generating power. Can contribute to the stable supply of electricity and steam.

  According to a third aspect of the present invention, the pump flow rate control means is based on a marginal water level difference that is a difference between a minimum water level at which the pump can be operated and a water level of the pump tank, and a rate of change of the water level of the pump tank. The pump device according to the first or second aspect is characterized by being a means for controlling the flow rate of the pump accordingly.

  In the third aspect, the flow rate of the pump can be easily controlled appropriately based on the marginal water level difference calculated using the water level of the pump tank and the rate of change of the water level of the pump tank.

  According to a fourth aspect of the present invention, there is provided a pump tank that is installed in a sea area to capture seawater via a dust remover that captures dust and allows seawater to pass therethrough, a pump tank communicating with the water channel, and a suction port in the pump tank And a pump tank water level measuring means for measuring the water level of the pump tank, wherein the pump tank water level is measured from the water level of the pump tank measured by the pump tank water level measuring means. A pump device operating method is characterized in that the rate of change of the water level is calculated, and the flow rate of the pump is controlled in accordance with the water level of the pump tank and the rate of change of the water level of the pump tank.

  In the fourth aspect, since the flow rate of the pump is controlled according to the water level of the pump tank and the rate of change of the water level of the pump tank, it is possible to set the flow rate of the pump appropriately considering the influence of the tide level and the like. Therefore, seawater can be continuously taken in, and the flow rate of the pump can be increased as much as possible.

  According to the present invention, the flow rate of the pump can be appropriately controlled from the water level of the pump tank and the rate of change of the water level of the pump tank. Therefore, seawater can be continuously taken in, and the flow rate of the pump can be increased as much as possible.

  Hereinafter, the best mode for carrying out the present invention will be described. The description of the present embodiment is an exemplification, and the present invention is not limited to the following description.

  FIG. 1 is a schematic cross-sectional view of a pump device according to the present embodiment. As shown in FIG. 1, a pump device 1 includes a pump tank 2 communicating with a water channel, a pump 4 having a suction port 3 inserted into the pump tank 2, and a pump tank water level measuring device 5 for measuring the water level of the pump tank 2. (Corresponding to “pump tank water level measuring means” in claims), and the upper opening of the pump tank 2 is closed by a lid 6. Further, the drain port 7 of the pump 4 is connected to a condenser pipe of a condenser of a generator (not shown), and by adjusting the opening and closing of a condenser outlet valve 8 provided in the vicinity of the drain port 7, the pump 4 The flow rate can be increased or decreased. The flow rate of the pump 4 depends on the inherent performance of the pump 4 and the opening of the condenser outlet valve 8, and the flow rate value of the pump 4 is a pump flow meter provided near the drain outlet 7 of the pump 4. 9 can be measured. And the pump tank water level change rate calculation means 11 which receives the water level data of the pump tank 2 measured by the pump tank water level measuring device 5 and calculates the change rate of the water level of the pump tank 2, and the change rate of the water level of the pump tank 2 A control unit 13 having a pump flow rate control means 12 for receiving the data and the water level data of the pump tank 2 to obtain the optimum opening of the condenser outlet valve 8 and controlling the opening and closing of the condenser outlet valve 8 is provided.

  This pump apparatus 1 is used with the dust remover 20 installed in the sea area. The dust remover 20 has a roller 21 and a screen 22 that is a wire mesh attached to the roller 21, and the screen 22 intersects the water channel so that the lower part of the screen 22 is exposed in the water channel and the upper part is exposed on the water channel. It is arranged. In addition, in this embodiment, although it was set as the dust remover 20 which captures dust with the screen 22 which is a metal mesh, the form of a dust remover is not specifically limited, A general dust remover can be used.

  In the pump device 1, the seawater 23 is taken from the pump 4 as follows. In addition, the direction in which the seawater 23 flows through the water channel is the direction of arrow A in FIG. First, the seawater 23 flows into the water channel together with the dust 30 such as jellyfish. Since the dust 30 is captured by the screen 22, only the seawater 23 passes through the screen 22 and flows to the downstream side of the screen 22. The seawater 23 that has passed through the screen 22 flows to the pump tank 2 of the pump device 1 and is taken into the pump 4 from the suction port 3. Then, the taken seawater 23 is discharged from the drain port 7 to the condenser.

  In the present embodiment, an appropriate opening degree of the condenser outlet valve 8 is obtained from the water level of the pump tank 2 and the rate of change of the water level of the pump tank 2, and the condenser outlet valve 8 is set to the appropriate opening degree. The flow rate of the pump 4 is controlled. When the opening of the condenser outlet valve 8 is reduced and the flow rate of the pump 4 is reduced, the cooling water supplied to the condenser is also reduced, so that the output of the generator is reduced. When the opening degree of the outlet valve 8 is increased and the flow rate of the pump 4 is increased, the cooling water supplied to the condenser also increases, so the output of the generator may be increased.

  In the present invention, since the flow rate of the pump 4 is controlled in accordance with the water level of the pump tank 2 and the rate of change of the water level of the pump tank 2, the tide level and the pump 4 that have not been considered in the conventional control of the pump flow rate. The effect of the flow rate is also taken into account.

  More specifically, when the tide level is low, the amount of water flowing to the pump tank 2 decreases, so the water level of the pump tank 2 decreases, and when the tide level is high, the amount of water flowing to the pump tank 2 increases, so the water level of the pump tank 2 Goes up. Therefore, the tide level is reflected in the rate of change between the water level in the pump tank 2 and the water level in the pump tank 2. Moreover, when the flow rate of the pump 4 is large, the water level of the pump tank 2 is lowered, and when the flow rate of the pump 4 is small, the water level of the pump tank 2 is raised. Therefore, the flow rate of the pump 4 is reflected in the rate of change between the water level in the pump tank 2 and the water level in the pump tank 2. In addition, when the amount of dust 30 is large, the amount of water flowing to the pump tank 2 is reduced, so that the water level of the pump tank 2 is lowered, and when the amount of dust 30 is small, the amount of water flowing to the pump tank 2 is larger than when the dust 30 is large. Therefore, since the water level of the pump tank 2 rises, the influence of the dust 30 is also taken into consideration by considering the rate of change between the water level of the pump tank 2 and the water level of the pump tank 2.

  Therefore, according to the present invention, not only the dust 30 but also the effects of the tide level and the flow rate of the pump 4 are taken into account, so that more appropriate control of the pump 4, more specifically, the flow rate of the pump 4 can be controlled at an appropriate timing. Since adjustment can be performed with an appropriate amount of change, the seawater 23 can be continuously taken in, and the flow rate of the pump 4 can be increased as much as possible.

  On the other hand, conventionally, the flow rate of the pump 4 is reduced when the difference in water level between the front and rear of the dust remover 20 is a criterion for reaching the operation limit point at which the operation of the pump 4 can be continued. However, even if the water level difference before and after the dust remover 20 is the same, the operation limit point varies depending on the tide level and the flow rate of the pump 4. Therefore, in the conventional method of controlling the flow rate of the pump 4 based only on the difference in water level before and after the dust remover 20, it is not possible to determine an appropriate timing or reduction amount for reducing the flow rate of the pump 4, and the flow rate of the pump 4 is appropriately set. I couldn't control it. Further, since the seawater 23 is continuously taken in by the pump 4 and the seawater 23 flows from the dust remover 20 to the pump tank 2, the water level 40 of the pump tank 2 and the back water level 41 of the dust remover 20 are different. Therefore, even if the back surface water level 41 of the dust remover 20 is grasped, the water level 40 of the pump tank is not known and the flow rate of the pump 4 cannot be appropriately controlled.

  Table 1 below shows a specific example of processing for controlling the flow rate of the pump 4 in accordance with the water level of the pump tank 2 and the rate of change of the water level of the pump tank 2. In Table 1, the water level of the pump tank 2 when the dust 30 is not attached to the screen 22 is +500 mm, the water level of the pump tank 2 when the dust 30 is slightly attached to the screen 22 is ± 0 mm, and the jellyfish is attacked. The water level of the pump tank 2 in the case where a large amount of dust 30 adheres to the screen 22 is -1300 mm. The water level of the pump tank 2 is, for example, the water level of the reference surface where the pump 4 is installed is zero, the water level higher than this reference surface is positive and negative when it is lower, and the absolute value of the water level as the distance from the reference surface increases Is assumed to be large. Further, the rate of change of the pump tank 2 when the water level of the pump tank 2 is low with time is negative, and the rate of change of the pump tank 2 when the water level of the pump tank 2 is high with time is positive. And

  Table 1 shows that when the water level of the pump tank 2 is the water level of the pump tank 2 described on the left side of Table 1, the rate of change in the water level of the pump tank 2 is positive, zero, and negative depending on the case. It shows that the opening degree of the valve 8 is adjusted to the values shown in Table 1. The opening degree of the condenser outlet valve 8 is the same even when a certain time (for example, 5 hours in Table 1) elapses in the case of the water level of the pump tank 2 and the rate of change of the water level of the pump tank 2 in Table 1. The standard value set in consideration that the water level of the pump tank 2 does not become lower than the lowest water level at which the pump 4 can be operated (minimum water level). In Table 1, the water level of the pump tank 2 is only +500, 0, -1300 mm, but other water levels are also standardized.

  For example, when the water level of the pump tank 2 in the rated operation state (initial state) is measured, it is +500 mm, and the flow rate of the pump 4 when the opening degree of the condenser outlet valve 8 is 100% is 13.5 t / h. . In this case, the minimum water level is -1400 mm. The minimum water level is a value specific to the pump 4 depending on the performance of the pump 4 and the flow rate of the pump 4, and is determined by the standard of the pump 4, but it can be obtained independently with reference to this. Good. The difference between the minimum water level-1400 mm and the water level of the pump tank 2 (allowable water level difference) is also shown in parentheses in Table 1.

  And when a jellyfish strikes, since the dust 30 will adhere to the screen 22 in large quantities, the water level of the pump tank 2 will fall. The water level of the pump tank 2 at this time is −1300 mm in the example of Table 1 above. At the water level of this pump tank 2, there is only a marginal water level difference from the minimum water level, and if the opening of the condenser outlet valve 8 is left at 100%, the minimum water level will be interrupted within 5 hours. The opening degree of the outlet valve 8 is reduced to reduce the flow rate of the pump 4. For example, the opening degree of the condenser outlet valve 8 is set to 60% (No. 9). Note that the flow rate of the pump 4 in this case is 9 t / h. The degree of opening of the condenser outlet valve 8 is adjusted according to the rate of change in the water level of the pump tank 2. For example, if the rate of change of the water level in the pump tank 2 is positive, the opening degree is 80% (No. 7). If the rate of change is zero, the opening degree is 70% (No. 8). (No. 9).

  If the opening degree of the condenser outlet valve 8 is decreased in this way, the flow rate of the pump 4 changes, so that the rate of change of the water level of the pump tank 2 and the water level of the pump tank 2 also change. Therefore, the opening degree of the condenser outlet valve 8 is controlled according to the rate of change of the water level of the new pump tank 2 and the water level of the pump tank 2. By continuing to control the opening degree of the condenser outlet valve 8, the pump can be continuously operated appropriately.

  If the opening degree of the condenser outlet valve 8 is changed, the flow rate of the pump 4 changes, so that the minimum water level also changes. The minimum water level after the opening degree of the condenser outlet valve 8 is set to 60% is determined by the standard of the pump 4 as described above, and is −1500 mm. Considering this new minimum water level, the opening degree of the condenser outlet valve 8 may be optimally controlled again. However, the minimum water level may be controlled by determining that the opening degree of the condenser outlet valve 8 of the pump 4 is 100%, that is, the minimum water level remains −1400 mm.

  Further, the flow rate of the pump 4 may be controlled according to the marginal water level difference that is the difference between the lowest water level at which the pump 4 can be operated and the water level of the pump tank 2 and the rate of change of the water level of the pump tank 2. The difference between the minimum water level and the water level in the pump tank 2 (the marginal water level difference) indicates how much the water level is marginal from the minimum water level, and the rate of change in the water level in the pump tank 2 is taken into account for this marginal water level difference. Thus, the flow rate of the pump 4 can be adjusted at an appropriate timing and with an appropriate amount of change.

  Specifically, a judgment value that is in the marginal water level difference is set, and when the value falls below the set value, the opening degree of the condenser outlet valve 8 is set in consideration of the rate of change of the water level in the pump tank 2. The flow rate of the pump 4 is controlled such that the flow rate of the pump 4 is reduced by decreasing the flow rate.

  For example, when the judgment value of the marginal water level difference is 600 mm, the opening degree of the condenser outlet valve 8 is reduced when the marginal water level difference is less than 600 mm. The degree to which the opening of the condenser outlet valve 8 is reduced is determined in consideration of the value of the rate of change of the water level in the pump tank 2, for example, 80% if the rate of change in the level of the pump tank 2 is positive. (No.7) If the rate of change is zero, the opening is 70% (No.8). If the rate of change is negative, the opening is 60% (No.9).

  For example, even if the marginal water level difference is larger than 600 mm (No. 1 to 6), the water level drops when the rate of change of the water level in the pump tank 2 is negative (No. 3, No. 6). Therefore, by decreasing the opening degree of the condenser outlet valve 8 in advance and reducing the flow rate of the pump 4, the lowering of the water level of the pump tank 2 can be suppressed and the pump 4 can be continuously operated. If the marginal water level difference is large enough and the rate of change of the water level of the pump 4 is zero or positive (No.1, No.2, No.4, No.5), the minimum water level is reached even after 5 hours. Therefore, it is not necessary to lower the opening degree of the condenser outlet valve 8 in particular, and it may be about 100%. Therefore, in Table 1, the opening degree of the condenser outlet valve 8 is maintained at 100%. .

  In addition, a fixed judgment value (for example, 0 mm) is set for the water level of the pump tank 2, and when the water level of the pump tank 2 is equal to or higher than this judgment value, the condensate is reconstituted according to the rate of change of the water level of the pump tank 2. When the opening of the condenser outlet valve 8 is controlled not to be increased or changed, and the water level of the pump tank 2 becomes less than this judgment value, the condenser outlet according to the rate of change of the water level of the pump tank 2 You may control the flow volume of the pump 4 to make the opening degree of the valve 8 small. Specifically, for example, assuming that the constant judgment value of the water level of the pump tank 2 is 0 mm, when the water level of the pump tank 2 is 0 mm or more, the rate of change of the water level of the pump tank 2 is a certain value or more (for example, zero or more). Then, the opening of the condenser outlet valve 8 is not changed (No. 4, 5), and if the rate of change of the water level in the pump tank 2 is less than the above-mentioned fixed value (negative), the opening of the condenser outlet valve 8 is changed. Control to decrease (No. 6).

  Further, when the rate of change of the water level of the pump tank 2 is negative, the flow rate of the pump 4 is decreased, and when the rate of change of the water level of the pump tank 2 is positive, the flow rate of the pump 4 is increased. Also good. More specifically, if the flow rate of the pump 4 is maintained as it is when the water level in the pump tank 2 is lowered with time, the flow rate of the pump 4 is decreased because the minimum water level may be reached. Further, when the water level of the pump tank 2 is increased with time, the water level rises even if the flow rate of the pump 4 is maintained as it is. Therefore, even if the flow rate of the pump 4 is increased, the minimum water level is not reached. Increase the flow rate of 4. Of course, when the water level of the pump tank 2 is rising, the current flow rate of the pump 4 may be maintained. In addition, since it is a major premise that the water level of the pump tank 2 is not less than the minimum water level, it is necessary to look at the water level of the pump tank 2 also in these cases.

  Further, in the above example, the flow rate of the pump 4 is controlled by dividing the rate of change of the water level of the pump tank 2 into positive, zero, and negative cases, but the pump 4 is controlled according to the numerical value of the rate of change of the water level of the pump tank 2. The flow rate may be adjusted. More accurate control of the flow rate of the pump 4 by adjusting the flow rate of the pump 4 according to the magnitude of the rate of change of the water level of the pump tank 2 as well as the positive / negative rate of change of the water level of the pump tank 2 Will be able to.

  INDUSTRIAL APPLICATION This invention can be utilized in the industry using the pump apparatus which takes in seawater through the dust remover installed in the sea area.

It is a schematic sectional drawing of the pump apparatus which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pump apparatus 2 Pump tank 3 Suction port 4 Pump 5 Pump tank water level measuring device 6 Lid 7 Drain outlet 8 Condenser outlet valve 9 Pump flow meter 11 Pump tank water level change rate calculation means 12 Pump flow rate control means 13 Control part 20 Dust removal Machine 21 Roller 22 Screen 23 Seawater 30 Dust 40 Water level of pump tank 41 Back water level of dust remover

Claims (4)

In a pump device installed in a water channel that takes in seawater through a dust remover that is installed in the sea area and captures dust and passes seawater,
A pump tank communicating with the water channel;
A pump with a suction port inserted into the pump tank;
Pump tank water level measuring means for measuring the water level of the pump tank;
A pump tank water level change rate calculating means for calculating a change rate of the water level of the pump tank from the water level of the pump tank measured by the pump tank water level measuring means;
A pump device comprising pump flow rate control means for controlling a flow rate of the pump according to a water level of the pump tank and a change rate of the water level of the pump tank.   The pump apparatus according to claim 1, wherein water discharged from the pump is used as cooling water for a condenser of a power plant.   The pump flow rate control means controls the flow rate of the pump in accordance with a marginal water level difference that is a difference between a minimum water level at which the pump can be operated and a water level of the pump tank, and a change rate of the water level of the pump tank. The pump device according to claim 1 or 2, wherein   A pump tank that is installed in a water channel that captures seawater through a dust remover that captures dust and passes seawater, and that is connected to the water channel, a pump that has a suction port inserted into the pump tank, and the pump tank A pump tank water level measuring means for measuring the water level of the pump tank, calculating the rate of change of the water level of the pump tank from the water level of the pump tank measured by the pump tank water level measuring means, An operation method of a pump device, wherein the flow rate of the pump is controlled in accordance with a water level of the pump tank and a rate of change of the water level of the pump tank.

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