JPS59120893A - Condensed water clean-up facility - 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] [Technical Field of the Invention] The present invention relates to a condensate filtration and desalination equipment that has a group of filter and desalters installed upstream of thermal or nuclear power generation equipment, and a group of desalters that is installed downstream thereof. the condensate purification equipment having a condensate desalination device installed, when the condensate filtration desalination device outlet water quality is better than the condensate purification equipment outlet water quality regulation value, the flow rate to the demineralizer group is controlled;
Concerning condensate purification equipment that reduces the load on demineralizers.

[Technical background of the invention]

Figure 1 shows a condensate purification facility installed in a nuclear power generation facility.

In the figure, reference numeral 1 denotes a nuclear reactor which is a steam generator, and steam is circulated in the direction of the arrow in the figure. That is, reactor 1
The steam that exits rotates the steam turbine 2, then the condenser 3
The water is condensed at the pump and sent out by the low-pressure condensate pump group 4. Next, it passes through the air extractor 12 and the ground condenser 13 in order, and then flows into the condensate purification equipment 5. In this condensate purification equipment 5, the condensate is filtered and desalted by a filter demineralizer group 5a in a condensate filtration and desalination device, and then desalted by a demineralizer group 5b in a condensate desalination device. Next, it is sent out by the high-pressure condensate pump group 6, heated by the low-pressure feedwater heater 7, then sent out by the feedwater pump group 8, further heated by the high-pressure feedwater heater group 9, and returned to the reactor 1. In addition, the filtration demineralizer group 5a and the demineralizer group 5b are provided with bypass channels passing through bypass valves 10 and 11, respectively.

The reason why the condensate filtration and demineralization device 5a is provided in the condensate purification equipment 5 is that the condensate demineralization device 5b alone has a limit in meeting the water quality required from the reactor water supply. Since its ability to treat undissolved solids in condensate was poor, it was installed to remove the undissolved solids.

Of these bypass valves 10 and 11, the condensate filtration and desalination device bypass valve 10 is normally closed, but if the differential pressure between the inlet and outlet of the condensate filtration and desalination device is high or the filtration and desalination device The bypass valve 10 is closed based on the differential pressure between the inlet and outlet of the bypass valve 5a as well as a signal issued from outside the device, thereby interlocking equipment protection and plant protection.

Regarding the condensate desalination device bypass valve 11, there is no particular interlock that forces it to open, and opening and closing depends on the judgment of the operator. The bypass valve 11 is used mostly during times other than normal operation, and in particular, when flushing the system, the bypass valve 11 is opened for fear of contaminating the resin with dirty water.

However, even during normal operation, if a situation occurs that covers the equipment or equipment, the bypass valve 11 may be temporarily opened at the discretion of the operator.

[Problems with background technology]

During normal operation, all of the filtration demineralizer group 5a and the demineralizer 5b are operated, leaving a reserve tower in order to completely purify the condensate. The former filtration demineralizer group 5a has the ability to remove mainly undissolved solids such as iron rust in condensate, but the filter medium used in this device is used in the downstream condensate demineralizer. Because it is made from bead-shaped ion exchange resin that is made into powder using a special machine, it has the ability to remove impurity ions from condensate. Therefore, the inlet water quality of the condensate filtration and desalination equipment during normal operation can sufficiently meet the condensate purification equipment outlet water quality standards based on experimental results or operational results.

In this case, although the condensate purified by the condensate filtration and desalination equipment meets the water quality standards at the outlet of the condensate purification equipment,
Furthermore, water is purified in a condensate desalination device, which mainly removes impurity ions from condensate through ion exchange reactions, but it also has the ability to filter out a small amount of undissolved solids. The condensate that has passed through the condensate desalination device is further purified, and the quality of the condensate water at the outlet of the condensate purification device is more than sufficiently exceeded.

Excessively improving the water quality is not bad in terms of the quality of water supplied to the reactor, but although sufficient water quality may be obtained with condensate filtration and desalination equipment, downstream condensate desalination equipment Passing the entire amount of condensate through the demineralizer group 5b eats up the ion exchange capacity of the ion exchange resin in the demineralizer group 5b.
This will promote a reduction in the operating time of b. As a result, the frequency of regeneration of the ion exchange resin increases, resulting in an increase in radioactive liquid waste during regeneration. Needless to say, an increase in the amount of radioactive waste is not a good thing; taking into account the cost of recycling resin, the cost of processing waste, and the final disposal of waste storage, efforts must be made to reduce the amount of radioactive waste.

Moreover, the above circumstances are not limited to nuclear power generation facilities but also apply to thermal power generation facilities.

[Purpose of the invention]

The present invention has been made in view of these points, and when the water quality at the outlet of the condensate filtration and desalination equipment becomes better than the water quality at the outlet of the condensate purification equipment, the purification burden on the condensate desalination equipment can be reduced, and each desalination The purpose is to provide condensate purification equipment that can prevent the ion exchange capacity of the ion exchange resin in the salt chamber group from being exhausted, reduce the frequency of regeneration of the ion exchange resin as much as possible, and reduce the amount of radioactive waste generated. shall be.

[Summary of the invention]

The present invention provides a condensate purification equipment having three condensate over-desalination devices and a condensate desalination device, in which a bypass flow path is provided to bypass each of the filtration demineralizer group and the demineralizer group, and each bypass flow path is provided. A bypass valve is installed in the condensate desalination system, and a condensate purification equipment outlet water quality detection device is installed on the outlet side of the condensate desalination equipment, and when the condensate filtration and demineralization equipment outlet water quality is better than the condensate purification equipment outlet water quality standard value, the condensate purification equipment outlet water quality detection device is installed. A control device is installed to fully open the bypass valve installed in the bypass flow path of the water desalination equipment, which reduces the purification burden on the condensate desalination equipment and allows ion exchange of the ion exchange resin in each desalination equipment group. It is characterized by preventing capacity consumption and reducing playback frequency.

[Embodiments of the invention]

Hereinafter, the present invention will be described with reference to embodiments shown in FIGS. 2 to 5.

The embodiments shown in FIGS. 2 to 4 are applied to condensate/cooling systems of nuclear power generation equipment.

In FIG. 2, reference numeral 21 denotes a nuclear reactor, and its outlet and inlet are connected by a condensate/cooling water channel 22.

In the condensate/cooling water passage 22, from the upstream side to the downstream side, a steam turbine 23, a condenser 24, a low-pressure condensate pump group 25, an air extractor 26, a ground condenser 27, a condensate purification equipment 28, A high-pressure condensate pump group 29, a low-pressure feedwater heater 30a, a water supply pump 31, and a high-pressure feedwater heater 30b are arranged in this order. The air extractor 26, the ground condenser 27, the condensate purification system 28, the low pressure feed water heater 30
a is between each pump group 25 and 29 or 2
This is an intermediate device interposed between 9 and 31.

In a condensate cooling water system having such a configuration, high-temperature, high-pressure steam discharged from the nuclear reactor 21 performs work in the steam turbine 23 and is converted into condensate in the condenser 24 . This condensate is pumped to pump 25
The pressure of the steam is increased by a low-pressure condensate pump group 25 consisting of a, 25b, and 25c, and the steam is cooled by an air extractor 26 and a grand condenser 27, and then reaches a condensate purification facility 28 where it is purified. Next, the condensate is pumped by pumps 29a, 29b,
The pressure is further increased by the high-pressure condensate pump group 29 consisting of pumps 29c, then heated and heated by the low-pressure feedwater heater 30a, and then the pressure is further increased by the feedwater pump group 31 consisting of pumps 31a, 31b, and 31c, and then the high-pressure feedwater heater group The water is heated at 30b and then supplied to the reactor 21.

The condensate purification equipment 28 is for removing impurity ions, undissolved solids, radioactive substances, etc. contained in the condensate, and in this embodiment, it has an upstream filtration desalination section 28a and a downstream desalination section. 28b.

Furthermore, the condensate purification installation 28 is provided with a condensate filtration and desalination device bypass valve 28c in a bypass flow path that bypasses the entire filtration and desalination section 28a, and a bypass flow path that bypasses the entire filtration and desalination section 28b. A condensate desalination device bypass valve 28d is provided in the channel. These bypass valves 28c,
d is closed during normal operation, and is opened to bypass part or all of the condensate when there is an abnormality such as an abnormal differential pressure or a failure in the filtration demineralization section 28a or demineralizer 28b, or as necessary. It is something that will be done.

Sampling points 49 and 57 are installed at the outlet of each device to monitor the water quality after purification, and the water quality is constantly monitored and a signal such as an alarm is issued if an abnormality occurs in the water quality. It has become.

To explain further, as shown in FIG. 3, the condensate purification equipment 28 includes a condensate filtration and desalination device on the upstream side and a condensate desalination device 52 on the downstream side.

That is, the reference numeral 41 in the condensate filtration and demineralization device 44 is the inlet main pipe of the 3-over demineralizer 44a, and the reference numeral 48 is the outlet main pipe of the 3-over demineralizer 44a. Between these main pipes 41 and 48, a plurality of (for example, 10 systems) purification equipment systems 47a, 4
7b...47n are connected. These purification equipment systems 47a, 47b, . 45a and an outlet valve 46a are sequentially arranged.

Similarly, the reference numeral 50 in the condensate demineralizer 52 represents the demineralizer 5
2a is an inlet main pipe, and numeral 56 is an outlet main pipe of the demineralizer 52a. There are a plurality of (
For example, 10 series) purification equipment systems 55a, 55b...5
5n is connected. These competing equipment systems 55a, 55b, .
, a demineralizer 52a, a strainer 53a, and an outlet valve 54a are arranged in this order. In addition, a sampling line 4 is installed at the outlet of each device to monitor the water quality of condensate.
In addition, necessary water quality monitoring items (e.g. conductivity, turbidity, etc.) are provided at the condensate 3 over-desalination equipment outlet water quality detection device 58 and the condensate purification equipment outlet water quality detection device 60. is detected and sent to the control device 59 as electrical signals 49a, 57a.

Here, in order to display the water quality and adjust the load reduction of the demineralizer group, each device in the condensate demineralizer 52 (inlet valve 5
1a, the outlet valve 54a, and the bypass valve 28d) to adjust the opening and closing of the valves.

The inlets 51a to 51a and the outlet valves 54a to 54n, excluding the backup tower, are kept open during normal operation, and
It is used as a load reduction means for the demineralizer groups 52a to 52n. The bypass valve 28d maintains a closed state during normal operation, and is used as a means for reducing the load on the demineralizer groups 52a to 52n, and also as a means for reducing the load from equipment or plants.
This is used as a means for bypassing the demineralizer groups 52a to 52n due to the high demineralizer differential pressure (high differential pressure, etc.).

Next, the operation of this embodiment will be explained.

In the condensate/cooling water system having the above configuration, as an example, the outlet water quality 58 of the condensate filtration and desalination device 44 is determined by the condensate purification installation 28.
A case where the outlet water quality is better than 60 will be explained. In this case, the signals outputted from the respective detection devices 58 and 60 are processed by logic within the control device 59 and "detection device 58
The water quality is better than the water quality specified by the condensate purification equipment 28,
and that the water quality of the detection device 60 is not worse than the water quality standards specified by the condensate purification equipment 28.
An open signal is issued from the control device 59 to the bypass valve 28d, and the bypass valve 28d is fully opened accordingly. As a result, the condensate flowing to the demineralizer groups 52a to 52n is bypassed, the flow rate of condensate flowing to the demineralizer groups 52a to 52n is reduced, and the load on the demineralizer groups 52a to 52n is reduced. The bypass valve 28d in this case is designed to completely bypass the condensate flow rate when the inlet/outlet valve of the demineralizer group is fully closed, and has a diameter of 1.
It reaches about 18 inches in the 100,000 class.

Inlet/outlet valves 51a-n, 54a-n of demineralizer groups 52a-n
When the bypass valve 28d is fully open, the bypass flow rate is half or more of the total condensate flow rate.

In addition, in this embodiment, the bypass valve 28d fully open signal is used as a permission signal, and the inlet/outlet valves 51a of the demineralizer groups 52a to 52n are
-n, 54a-n are sequentially fully closed automatically or remotely manually and the inlet/outlet valves of all demineralizer groups are closed, thereby achieving full bypass of the condensate by the bypass valve 28d. In this case, the load on the demineralizer groups 52a to 52n is completely eliminated.

Next, during the load reduction operation of the demineralizer groups 52a to 52n (while bypassing part or all of the condensate), the condensate filtration and desalination equipment outlet water quality detection device 58 or the condensate purification equipment exit water quality detection device A case will be described in which the water quality detected by the water pipe 60 becomes worse than the specified value of the condensate purification equipment outlet water quality.

In this case as well, the signals output from the respective detection devices 58 and 60 are not satisfied in the controller 59, so a close signal is output from the controller 59 to the bypass valve 28d, and the bypass valve 28d is closed. The valve 28d is fully closed. This will return to normal operation and demineralizer group 5
2a-n load reduction operation is canceled.

In this case, the bypass valve 28d is the open part of the demineralizer group 52a.
~52n inlet/outlet valves 51a-51n, 54a-54n (
When one tower is on standby as a standby, when two or more towers are closed, the inlet/outlet valves 51a to 51n of all demineralizer groups are closed.
, 54a to 54n (all demineralizers except one tower when there is a standby tower) is used as a permission signal, and the bypass valve 28d is fully closed to return to normal operation.

According to the operation control method detailed above, when the water quality at the outlet of the condensate filtration and desalination equipment is good (when the quality of water at the exit of the condensate purification system is better than the regulations), the purification burden on the demineralizer group can be eased, and the ion exchange The frequency of resin regeneration is reduced, and it is possible to reduce the amount of radioactive waste generated by regeneration. Furthermore, as mentioned above, the operation control is performed using the condensate desalination equipment bypass 2.
If 8d is installed, it is possible to reduce the load on the demineralizer group at low cost with only a slight increase in the cost of instrumentation control. In existing plants, this method can be easily adopted at low cost.

In this example, in order to reduce the load on the demineralizer group,
If the demineralizer group is isolated, there is no problem for a short period of time, but if it is isolated for a long time, water with poor purity that is not ion-exchanged will come out at the beginning of the water flow, so the recirculation pump 61 should be used before water flow. A break-in operation is required to circulate water and improve water quality.

The embodiment of FIG. 4 solves this problem. Note that the description of the flow paths in the non-example is almost the same as that in FIG. 3, so the same reference numerals are given and the description is omitted. slightly third
The difference from the diagram is that the condensate desalination device bypass valve 28d has been changed to a flow rate regulating valve.

In this embodiment, when performing a demineralizer group load reduction operation, the inlet/outlet valve 51a of each demineralizer group 52a to 52n other than the standby tower is
-n, 53a-n, and the flow rate of condensate flowing to each demineralizer group 52a-52n is adjusted by adjusting the opening degree of the bypass valve 28d.

The opening degree can be adjusted by adjusting the opening degree of the bypass valve 28d using an electric signal sent from the control device 59 depending on the level of water quality at the outlet of the condensate filtration and demineralization equipment, and by adjusting the opening degree of the bypass valve 28d by using an electric signal issued from the control device 59. There is a method of setting the opening degree arbitrarily. By doing this, not only does it become unnecessary to open and close the inlet/outlet valves 51a-n, 53a-n of each demineralizer 52a-n, but also condensate always flows through each demineralizer group 52a-n. Therefore, it is possible to prevent the deterioration of water quality caused by the isolation of the demineralizer groups 52a to 52n. However, in this case, when the bypass valve 28d is fully open, in order to bypass as close to the full amount of condensate as possible, it is necessary to naturally increase the diameter of the bypass valve 28d to reduce the pressure loss in the main line as much as possible. By doing this, the amount of condensate flowing to the demineralizer group is reduced and the load on the demineralizers is reduced, producing better effects.

〔Effect of the invention〕

As explained above, in a power generation plant in which the condensate purification equipment is equipped with a condensate filtration desalination device and a condensate desalination device, the water quality at the outlet of the condensate three over desalination devices is Based on the achievement of water quality when the water quality is better than the specified value, a start signal is generated to open the bypass valve of the condensate desalination equipment in order to reduce the load on the demineralizer group of the condensate desalination equipment. The burden on the resin in each demineralizer can be reduced by adjusting the opening or operating the bypass valve and demineralizer inlet/outlet valve to reduce the flow rate of condensate to each demineralizer. This has the effect of extending the life of the resin, resulting in a synergistic effect of reducing the frequency of regeneration and reducing the amount of waste generated. Furthermore, the present invention can be constructed at low cost by adding a control function to open and close the bypass valve, and in this case, it is possible to reduce the burden on each demineralizer group, and furthermore, it is possible to add a control function to open and close the bypass valve. It also has the advantage that it can be implemented without requiring major changes.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing a conventional condensate water supply system, Fig. 2 is a system diagram showing a condensate and water supply system to which the equipment of the present invention is applied, and Fig. 3 is a system diagram showing the equipment of the invention. The enlarged system diagram, FIG. 4, is a diagram equivalent to FIG. 3 showing another embodiment of the present invention. 22... Condensate/cooling water flow, 28... Condensate purification equipment, 28a... Filtration desalination section, 28b... Desalination section, 28
c Condensate filtration and desalination device bypass valve, 28d... Condensate desalination device bypass valve, 44... Condensate filtration and desalination device, 44a
...filtration desalination device, 52...condensate desalination device bypass valve, 52a... desalination device, 58... condensate filtration desalination device outlet water quality detection device, 59... control device, 60... Condensate purification equipment outlet water quality detection device. Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] 1. A condensate filtration desalination device in which a plurality of filtration demineralizer groups are connected in parallel to a condensate system on the steam turbine outlet side, and a plurality of demineralizers downstream of this condensate filtration desalination device. In a condensate purification equipment that removes solid matter, impurity ions, etc. contained in condensate using a condensate desalination device in which a group of salters are connected in parallel, a bypass that bypasses the filtration demineralizer group and the desalination group, respectively. A flow path is provided, a bypass valve is provided in each bypass flow path, a condensate filtration desalination device outlet water quality detection device is provided on the outlet side of the condensate filtration desalination device, and a condensate filtration desalination device outlet water quality detection device is provided on the outlet side of the condensate desalination device. A condensate purification equipment outlet water quality detection device is installed, and when the condensate filtration and desalination equipment outlet water quality is better than the condensate purification equipment outlet water quality standard value, the bypass valve installed in the bypass flow path of the condensate desalination equipment is fully opened. A condensate purification equipment characterized by being equipped with a control device for controlling the 2. The condensate purification equipment according to claim 1, wherein the bypass valve is a flow control valve.