JPS5970999A - Bypass device of condensed water processing device and its control method - 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 bypass device for a condensate treatment device including a condensate desalination device or a hard water filtration device used for purifying the quality of condensate in a nuclear power plant. and its ri+ control method.

[Technical backstory of the invention and its problems]

The desalination equipment or one-pass equipment that makes up the condensate treatment equipment of a nuclear power plant removes impurities or dissolved water that has entered the condensate when it is sent back to the reactor after passing through the turbine. By filtering out impurities and desalting them, the quality of the water supplied to the reactor is maintained at a high level, and the amount of impurities entering the reactor is reduced. In many cases, an ionic father exchange resin is used, and the resin is replaced or Ti is regenerated from time to time depending on usage conditions to maintain filtration and desalting performance. Moreover, these systems themselves are
A water retention pump (or low pressure condensate pump, hereinafter referred to as LPCi') and a condensate boost pump (or high pressure condensate pump, hereinafter referred to as HPCP') provided in the condensate main pipe led from the turbine condenser. A filtration device, a desalination device, or both connected in series are installed between the two, and when the condensate passes through these devices, filtration, desalination, etc. are carried out.

These ascites treatment devices are equipped with a bypass circuit so that the flow of water is not obstructed even in the unlikely event that an abnormality occurs.
When the differential pressure in the device increases due to an abnormality in the valve of the bypass device or a sudden increase in flow rate, the valve provided in the bypass circuit is automatically opened.

Generally, the conditions for the valve used in this bypass circuit are to ensure a flow rate immediately when the differential pressure increases;
Also, valve leakage during normal operation is minimal. For this reason, a gate valve (also referred to as a gate valve) having the above characteristics is used in the bypass circuit.

The general characteristics of gate valves are as shown in Figure 41. If the valve starts to open slightly, the flow starts immediately, and if the 10th section is also open (the valve is fully open, it is almost the opposite of the state of 1 (?). In the ga1 diagram, the opening degree (% stroke) of the valve is taken as the axis, and (ri) is taken as the secondary axis, and the cv value of the valve is taken as the secondary axis. (vIllK is the well-known (viE
It is a value obtained by the formula of 2, and represents the resistance or ease of flow of the valve, and the larger &ml is, the easier it is to flow. It's the front.

Now, although this is a gate valve with temporality on μ, there is a very troublesome peak in the characteristic when the valve is closed, CI″i.

The theory is that the valve was opened due to some abnormality and the flow r# was secured, but if the problem is removed and the valve is closed again (i.e., the condensate treatment equipment should be serviced). In this case, the bypass flow is suddenly narrowed down by about 10%, and the fluid suddenly flows into the water treatment chamber. It is known that when the condensate is open, the resistance is lower than in the condensate treatment equipment, so most of the water flows through the bypass circuit.

Therefore, if such sudden fluctuations in flow occur during operation, the differential pressure in the device may temporarily increase, or the response may not be in time if the device is adjusting the flow rate, etc. Also, since the differential pressure of the device increases rapidly, 1 (PC
There is a possibility that the suction pressure of P will decrease, and the discharge pressure of the water pump will decrease, and the water supply to the reactor will be interrupted. Furthermore, in extreme cases, the pump may trip due to a drop in the suction pressure of Ml-'CP.

[Purpose of the invention]

In view of the above points, an object of the present invention is to maintain the conventional characteristics and immediately secure bypass flow when bypass is necessary, and to gradually flow to the processing equipment side when the bypass circuit valve is closed, thereby solving the above problems. An object of the present invention is to provide a bypass device for a condensate treatment device and a control method thereof that can prevent the occurrence of.

[Invention Bei2? Summary: The present invention relates to a condensate treatment system having a bus path interposed in a water mother U that connects a turbine condenser of a nuclear reactor and a water inlet on the reactor side. !l!G) on the device,
A globe valve and a gate valve are connected in series in the bypass path, and the globe valve and gate valve are selected to open and close 1ulJ.
This is a bypass system for an ascites treatment system that has a control device that can fill the ascites. In 2Q), a globe valve and a gate valve which are connected in series to the bypass channel are held in an open state, and the The gate valve is held in a closed state, and the bypass 'KI is held in a closed state, and the gate valve is removed by one step, and the pass≧・6 held in the closed state is released by +iA, and the above-mentioned ball is Both the shape valve and the gate valve are kept open to keep the bypass passage open, the globe valve is closed, the gate valve is closed, and the globe valve is opened. This is a control method for a bypass device of a condensate treatment device, which executes control to close the bypass path kept in the open state.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a bypass device for a condensate treatment device and a control method thereof according to the present invention will be described below with reference to the drawings.

As shown in Figure 2, the LPCP installed in the condensate main pipe l
On the downstream side of 2, a condensate treatment device 3 and an HPCP 4 are installed in series. In addition, it branches from the condensate main pipe 1 to the condensate treatment device 3.
A bypass passage 5 is provided in parallel with the bypass passage 5, and a globe valve 6 and a gate valve 7, each of which is an electric valve, are inserted in series in the bypass passage 5.

The opening and closing of the globe valve 6 and the gate valve 7 are controlled using a control device 8, respectively.

The globe valve 6 is given a globe valve opening/closing signal 9 from the control device 8, and is provided with a connection for transmitting the open/closed state to the control device 8 as a globe valve open/close display signal 10. The gate valve 7 is provided with a connection that receives a gate valve open/close signal 11 from the control device 8 and sends the open/close state to the control device 8 as a gate valve open/close display signal 12. The control device 8 is given a valve opening/closing command signal 14 from a command device [3], the command device 13 is provided with an opening/closing command switch, and a signal 15 from a power plant control system (not shown) is inputted. It is connected.

The condensate treatment device 3 may be composed of a filtration device or a desalination device, or may be a cascade connection of a filtration device and a desalination device.

The device of the present invention configured in this way can close the bypass path 5 if either the globe valve 6 or the gate valve 7 is closed, and the condensate treatment device 3 can normally be closed by one valve. When the machine is in use, the globe valve 6 is opened and the gate valve 7 is closed. When the bypass path 5 is open, both the globe valve 6 and the partition 597 are open.

Next, a method of controlling the apparatus of the present invention described above will be described. When the bypass passage 5 is closed and all the condensate flowing through the condenser al is passing through the condensate treatment device ti3, the globe valve 6 is open and the partition -yP7 is closed. When the bypass path 5 is to be opened, when a valve opening signal is given from the command device 13 to the controller 8, the gate valve opening/closing signal 11 commands opening, and the gate valve 7 is opened. Since the gate valve 7 has the valve opening vs. CV value characteristics shown in FIG. When closing the bypass passage 5 which is maintained in the same state and has a flow rate, the controller 8 is sent from the command unit 13.
When a valve closing signal is given to the globe valve opening/closing signal 9, the globe valve opening/closing signal 9 commands closing, the globe valve 6 is closed, and the bypass path 5 is closed.

When the globe valve 6 is completely closed and the globe valve open/close display signal 10 sends a close display signal, the controller 8 issues a gate valve open/close signal 11 to command closure, and the gate valve 7 is also closed. When the closing of the gate valve 7 is completed and the crab 2 sends a closed display signal, the +u-sial device 8 issues a globe valve open/close signal 9 to command opening, and the globe valve 6 will be released.

In this way, the bypass path 5 is immediately closed by the closing signal issued from the command unit 13, and when the bypass path is opened next, the gate valve 7 is opened 11tlJ.
The state where the bypass path 5 is secured can be set only by the control.

FIG. 3 shows the mutual relationship between the globe valve 6 and the gate valve 7 when the above control is performed.

According to the control method of the present invention, when closing the bypass passage 5, the globe valve 6 is first used. shaped valve 6
Since the CV value rises slowly with opening of the valve, the flow rate of the bypass passage 5 gradually decreases, and a sudden rise in the differential pressure between the input and output of the condensate treatment device 3 can be prevented.

Figure i45 shows the bypass path 50 when the above control is performed.
The hysteresis characteristic of opening degree-cv value is shown.

〔Effect of the invention〕

As explained above, according to the present invention, when opening the bypass path of the condensate treatment device, it is possible to rapidly secure the bypass flow due to the characteristics of the gate valve, and when the bypass path is closed. At times, the characteristics of the globe valve allow the bypass flow to be shut off gradually, thereby preventing disturbances from spreading to the power plant 11J control system due to sudden changes in the differential pressure between the input and output of the water treatment equipment. Remarkable effects can be obtained.

[Brief explanation of the drawing]

Figure J1 is a characteristic diagram showing the relationship between the valve opening degree of partition JT' and the CV value, Figure 742 is a system connection diagram showing the bypass device of the condensate treatment device according to the present invention, and Figure 3 is a diagram showing the relationship between the valve opening degree of partition JT' and the CV value. Time 1 representing the ili control method of the bypass device of ascites treatment device J
Figure 44 is an I characteristic diagram showing the relationship between the opening degree and cv value of the globe valve, and Figure 5 shows the relationship between the opening degree and cv value of the bypass passage in Figure 2.
It is a characteristic diagram showing the relationship of v values. 1... Condensate main pipe 3... Water conditioning treatment device 5...
・Bypass path 6... Globe valve 7... Gate valve
8... Control device (7317) Representative Patent Attorney Norihiko Norihiko (1i (1 person) Fig. 1 Fig. 2/, S Fig. 3 "'l",, 1

Claims (1)

[Claims] 1. In a condensate treatment device having a bypass passage interposed in a condensate main pipe that connects a turbine condenser of a nuclear power plant and a water supply port on the reactor side, the above-mentioned devices are connected in series. A bypass device for a condensate treatment device, comprising a globe valve and a gate valve provided in a bypass path, and a control device capable of selectively controlling opening and closing of the globe valve and gate valve. 2. In a condensate treatment device having a bypass path interposed in a condensate main pipe that connects a turbine condenser of a nuclear power plant and a water supply port on the reactor side, the system is connected in series to the bypass path. The globe valve and the gate valve are arranged such that the globe valve is held in an open state, the gate valve is held in a closed state to maintain the bypass passage in a closed state, and the gate valve is opened to maintain the bypass passage in a closed state. The bypass passage that has been kept closed is opened, the globe valve and the queen gate valve are both kept open to keep the bypass passage open, the globe valve is closed, and the gate valve is then opened. 1. A method of controlling a bypass device of a condensate treatment device, comprising: closing a globe valve, and then opening a globe valve to close the bypass path kept in the open state.