Industrial steam supply condensation water return system of nuclear power plant and control method

Abstract

The invention relates to the field of control, in particular to a nuclear power plant industrial steam supply condensation water return system and a control method. The system comprises a first condensed water mother pipe, wherein the rear end of the first condensed water mother pipe is respectively connected to a first unit condensed water main pipeline and a first unit condenser through two branches; the rear end of the second condensed water mother pipe is respectively connected to a second unit condensed water main pipeline and a second unit condenser through two branches; the two primary water supply preheating systems are connected with the front end of the first condensed water main pipe through condensed water pipelines at the rear ends of the primary water supply preheating systems, and collected condensed water obtained after heat exchange of the steam conversion equipment is conveyed to the condensed water main pipe; the two first-stage feed water preheating systems are connected with the front end of the second condensed water main pipe through condensed water pipelines at the rear ends of the first-stage feed water preheating systems, and collected condensed water obtained after heat exchange of the steam conversion equipment is conveyed to the condensed water main pipe; and a plurality of flowmeters are respectively arranged on each condensed water main pipe in parallel. When the unit normally operates, condensed water after heat exchange of the steam conversion equipment flows back to the main condensed water pipeline of the unit through the condensed water mother pipe; and under the working condition that the unit is started, condensed water after heat exchange of the steam conversion equipment flows to the condenser through the condensed water mother pipe. Reutilization of the condensation water is guaranteed, and meanwhile safety and stability of a secondary condensation water system are guaranteed.

Description

Technical Field

[0001] The invention relates to the field of control, and in particular to a nuclear power plant industrial steam supply condensate return system and a control method. Background Art

[0002] The main steam of the nuclear power secondary circuit is used for steam energy supply after heat exchange through the steam conversion equipment, but the condensed water after heat exchange cannot be collected, resulting in energy loss.

[0003] At present, in steam heating systems, condensate recovery is an important energy-saving measure. However, in the field of comprehensive utilization of nuclear energy, there is no experience to draw on for using the secondary circuit steam of nuclear power plants as a heat source to produce industrial steam.

[0004] The main difficulty is how to achieve condensate recovery while ensuring the safety and stability of the secondary circuit condensate system and avoiding the mixing of media from different units. There is currently no precedent in the field of comprehensive utilization of nuclear energy. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a nuclear power plant industrial steam supply condensate return system and control method, which ensures the reuse of condensate and at the same time ensures the safety and stability of the secondary condensate return system.

[0006] The present invention provides a nuclear power plant industrial steam supply condensate return system, comprising:

[0007] The first condensate jelly pipe has a rear end connected to the first unit condensate main pipeline and the first unit condenser through two branches;

[0008] The rear end of the second condensate jelly pipe is connected to the condensate main pipeline of the second unit and the condenser of the second unit through two branches;

[0009] Two primary feedwater preheating systems are connected to the front end of the first condensate jelly pipe through the condensate pipe at the rear end thereof, and the condensate collected after heat exchange of the steam conversion equipment is transported to the condensate jelly pipe;

[0010] Two primary feedwater preheating systems are connected to the front end of the second condensate jelly pipe through the condensate pipe at the rear end thereof, and the condensate collected after heat exchange of the steam conversion equipment is transported to the condensate jelly pipe;

[0011] Multiple flow meters are connected in parallel on each condensate jellyfish tube.

[0012] The branch connected to the main condensate pipeline of the first unit is provided with an isolation valve for the main condensate pipeline of the first unit; the branch connected to the condenser of the first unit is provided with an isolation valve for the condenser of the first unit;

[0013] The branch line connected to the condensate main pipeline of the two units is provided with an isolation valve for the main condensate pipeline of the second unit; the branch line connected to the condenser of the second unit is provided with an isolation valve for the condenser of the second unit.

[0014] In a specific embodiment of the present invention, two primary feedwater preheating systems are connected to the front end of the first condensate main pipe through the first unit condensate pipe and the second unit condensate pipe respectively.

[0015] The other two primary feedwater preheating systems are connected to the front end of the second condensate main pipe through the condensate pipe of the first unit and the condensate pipe of the second unit respectively.

[0016] A first electric isolation valve is provided on the condensate pipeline of each first unit; a second electric isolation valve is provided on the condensate pipeline of each second unit.

[0017] In a specific embodiment of the present invention, a temperature measuring device and a pressure measuring device are provided on the first condensation jellyfish tube;

[0018] The second condensation jellyfish tube is provided with a temperature measuring device and a pressure measuring device.

[0019] In a specific embodiment of the present invention, there are at least three flow meters.

[0020] The present invention provides a method for controlling the return water of condensate from industrial steam supply in a nuclear power plant, comprising:

[0021] When the unit is operating normally, the condensate after heat exchange in the steam conversion equipment flows back to the main condensate pipeline of the unit through the condensate dam pipe;

[0022] Under the unit startup condition, the condensate after heat exchange in the steam conversion equipment flows to the condenser through the condensate jellyfish pipe.

[0023] In a specific embodiment of the present invention, when the unit is operating normally,

[0024] The isolation valve of the main condensate pipeline of the first unit and the isolation valve of the main condensate pipeline of the second unit are opened, and the isolation valve of the condenser of the first unit and the isolation valve of the condenser of the second unit are closed;

[0025] When the electric isolation valve of the heating main steam pipeline system of the first unit is fully open or fully closed, the electric isolation valve on the condensate pipeline of the first unit is opened or closed in linkage, and the electric isolation valve on the condensate pipeline of the second unit is closed or opened at the same time;

[0026] When the electric isolation valve of the heating main steam pipeline system of the second unit is fully open or fully closed, the electric isolation valve on the condensate pipeline of the second unit is opened or closed in conjunction, and the electric isolation valve on the condensate pipeline of the first unit is closed or opened at the same time.

[0027] In a specific embodiment of the present invention, under the unit startup condition, the main condensate pipeline isolation valve of the first unit and the main condensate pipeline isolation valve of the second unit are closed, and the condenser isolation valve of the first unit and the condenser isolation valve of the second unit are opened, so that the condensate flows to the condenser through the condensate jellyfish pipe.

[0028] In a specific embodiment of the present invention, it also includes:

[0029] When the observed liquid level of the evaporator is high, the isolation valve for the condenser of the first unit and the isolation valve for the condenser of the second unit will be opened automatically;

[0030] When the conventional island deaerator is at a high water level, the isolation valve for the condenser of the first unit and the isolation valve for the condenser of the second unit are automatically opened.

[0031] Compared with the prior art, the nuclear power plant industrial steam supply condensate return system and control method of the present invention has the following beneficial effects:

[0032] (1) Through the return water system, the steam heating condensate of two nuclear power units is recovered at the same time. While realizing the condensate recovery, the safety and stability of the secondary circuit condensate system are ensured, achieving the goal of energy conservation, emission reduction and improving economic benefits.

[0033] (2) Through ingenious control logic design, the condensate of the main steam after heat exchange in the steam conversion equipment can be diverted to different secondary circuit equipment when the nuclear power unit is in different operating conditions.

[0034] (3) Automatic control of condensate return and interlocking control of condensate return isolation valve to avoid mixing of secondary circuit media of the two units.

[0035] (4) The nuclear power plant's industrial steam supply condensate return control interlock effectively reduces the risk of human error.

[0036] (5) The measurement of condensate return flow rate is carried out through three-out-of-two calculation logic to ensure the reliability of the return flow rate in subsequent logical operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram showing the structure of the industrial steam supply condensate return system of a nuclear power plant;

[0038] In the figure, 1-first level feed water preheating system (NAB); 2-second level feed water preheating system (NAB); 3-third level feed water preheating system (NAB); 4-fourth level feed water preheating system (NAB); 5-condensate isolation valve A of the first unit; 6-condensate isolation valve A of the second unit; 7-condensate isolation valve B of the second unit; 8-condensate isolation valve B of the first unit; 9-condensate isolation valve C of the second unit; 10-condensate isolation valve C of the first unit; 11-condensate isolation valve D of the first unit; 12-condensate isolation valve D of the second unit; 13-condensate main pipe thermometer A; 14-condensate main pipe pressure gauge A; 15-condensate main pipe thermometer B ;16- condensate main pressure gauge B;17- flow meter A;18- flow meter B;19- flow meter C;20- flow meter D;21- flow meter E;22- flow meter F;23- isolating valve of main condensate pipeline for second unit;24- main condensate pipeline for second unit;25- isolating valve of main condensate pipeline for first unit;26- main condensate pipeline for first unit;27- isolating valve of condenser for second unit;28- isolating valve of condenser for first unit;29- condenser A for second unit;30- condenser B for second unit;31- condenser C for second unit;32- condenser A for first unit;33- condenser B for first unit;34- condenser C for first unit. DETAILED DESCRIPTION

[0039] In order to further understand the present invention, the embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the present invention.

[0040] The present invention makes full use of the existing resources of the nuclear power plant and simultaneously completes the recovery of steam condensate from two units by adding a new steam supply condensate return system, thereby achieving energy conservation and environmental protection in the production process and improving the economic benefits of the nuclear power steam heating project while ensuring the safe and stable operation of the existing nuclear power units.

[0041] The embodiment of the present invention discloses a nuclear power plant industrial steam supply condensate return system, such as Figure 1 As shown, including:

[0042] The first condensate jellyfish pipe, the rear end of which is connected to the first unit condensate main pipeline 26 and the first unit condenser through two branches;

[0043] The first unit condenser includes three units connected in parallel, namely, a first unit condenser A 32, a first unit condenser B 33, and a first unit condenser C 34;

[0044] The branch connected to the first unit condensate main pipeline 26 is provided with a first unit main condensate pipeline isolation valve 25; the branch connected to the first unit condenser is provided with a first unit condenser isolation valve 28;

[0045] The rear end of the second condensate jellyfish pipe is connected to the second unit condensate main pipe 24 and the second unit condenser through two branches;

[0046] The second unit condenser includes three units connected in parallel, namely, a second unit condenser A 29, a second unit condenser B 30, and a second unit condenser C 31;

[0047] The branch connected to the second unit condensate main pipeline 24 is provided with a second unit main condensate pipeline isolation valve 23; the branch connected to the second unit condenser is provided with a second unit condenser isolation valve 27;

[0048] Two primary feed water preheating systems, namely the first primary feed water preheating system 1 and the second primary feed water preheating system 2, are connected to the front end of the first condensate jelly pipe through the first unit condensate pipe and the second unit condensate pipe respectively, and the condensate collected after heat exchange of the steam conversion equipment is transported to the condensate jelly pipe;

[0049] Specifically,

[0050] A first unit condensate isolation valve A5 is provided on the first unit condensate pipeline A connected to the first level feed water preheating system 1, and a second unit condensate isolation valve A6 is provided on the second unit condensate pipeline A connected to the first level feed water preheating system 1;

[0051] A first unit condensate isolation valve B8 is provided on the first unit condensate pipeline B connected to the second primary feed water preheating system 2, and a second unit condensate isolation valve B7 is provided on the second unit condensate pipeline B connected to the second primary feed water preheating system 2;

[0052] Two primary feed water preheating systems, namely the third primary feed water preheating system 3 and the fourth primary feed water preheating system 4, are connected to the front end of the first condensate jelly pipe through the first unit condensate pipe and the second unit condensate pipe respectively, and the condensate collected after heat exchange of the steam conversion equipment is transported to the condensate jelly pipe;

[0053] Specifically,

[0054] A first unit condensate isolation valve C10 is provided on the first unit condensate pipeline C connected after the third primary feed water preheating system 3, and a second unit condensate isolation valve C9 is provided on the second unit condensate pipeline C connected after the third primary feed water preheating system 3;

[0055] A first unit condensate isolation valve D11 is provided on the first unit condensate pipeline D connected after the fourth primary feed water preheating system 4, and a second unit condensate isolation valve D12 is provided on the second unit condensate pipeline D connected after the fourth primary feed water preheating system 4;

[0056] Multiple flow meters are respectively connected in parallel on each condensation jellyfish tube, specifically:

[0057] At least three flow meters are provided on the first condensation jellyfish tube, namely flow meter D20; flow meter E21; flow meter F22;

[0058] The second condensation jellyfish tube is provided with the above three flow meters, namely flow meter A17, flow meter B18 and flow meter C19.

[0059] The first condensate main pipe is provided with a temperature measuring device and a pressure measuring device; respectively, a condensate main pipe temperature gauge B15; 16- condensate main pipe pressure gauge B16;

[0060] The second condensate jelly pipe is provided with a temperature measuring device and a pressure measuring device, which are a condensate main pipe thermometer A13 and a condensate main pipe pressure gauge A14 respectively.

[0061] The embodiment of the present invention also discloses a method for controlling the return of condensate from industrial steam supply in a nuclear power plant, comprising:

[0062] When the unit is operating normally, the condensate after heat exchange in the steam conversion equipment flows back to the main condensate pipeline of the unit through the condensate dam pipe;

[0063] The isolation valve of the main condensate pipeline of the first unit and the isolation valve of the main condensate pipeline of the second unit are opened, and the isolation valve of the condenser of the first unit and the isolation valve of the condenser of the second unit are closed;

[0064] When the electric isolation valve of the heating main steam pipeline system of the first unit is fully open or fully closed, the electric isolation valve on the condensate pipeline of the first unit is opened or closed in linkage, and the electric isolation valve on the condensate pipeline of the second unit is closed or opened at the same time;

[0065] When the electric isolation valve of the heating main steam pipeline system of the second unit is fully open or fully closed, the electric isolation valve on the condensate pipeline of the second unit is opened or closed in conjunction, and the electric isolation valve on the condensate pipeline of the first unit is closed or opened at the same time.

[0066] Under the unit startup condition, the condensate after heat exchange in the steam conversion equipment flows to the condenser through the condensate jelly pipe. The isolation valve of the main condensate pipeline of the first unit and the isolation valve of the main condensate pipeline of the second unit are closed, and the isolation valve of the condenser of the first unit and the isolation valve of the condenser of the second unit are opened, so that the condensate flows to the condenser through the condensate jelly pipe.

[0067] Also includes:

[0068] When the observed liquid level of the evaporator is high, the isolation valve for the condenser of the first unit and the isolation valve for the condenser of the second unit will be opened automatically;

[0069] When the conventional island deaerator is at a high water level, the isolation valve for the condenser of the first unit and the isolation valve for the condenser of the second unit are automatically opened.

[0070] In order to further understand the present invention, the nuclear power plant industrial steam supply condensate return system and control method provided by the present invention are described in detail below in conjunction with the embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0071] Example 1

[0072] The condensate of the main steam after heat exchange in the steam conversion equipment is led out through the condensate pipeline at the rear end of the first primary feed water preheating system 1, the second primary feed water preheating system 2, the third primary feed water preheating system 3 and the fourth primary feed water preheating system 4, and is collected to the first condensate mother pipe through the first unit condensate isolation valve A5, the second unit condensate isolation valve A6, the first unit condensate isolation valve B8, and the second unit condensate isolation valve B7 and sent back to the first unit secondary circuit condenser or the first unit main condensate pipeline; the condensate is collected to the second condensate mother pipe through the first unit condensate isolation valve C10, the second unit condensate isolation valve C9, the first unit condensate isolation valve D11, and the second unit condensate isolation valve D12 and sent back to the second unit secondary circuit condenser or the second unit main condensate pipeline;

[0073] The temperature and pressure of the first condensation jellyfish tube and the second condensation jellyfish tube are measured respectively.

[0074] When the unit is operating normally, the condensate of the main steam after heat exchange in the steam conversion equipment will flow to the main condensate pipeline through the main condensate pipeline isolation valve 25 of the first unit and the main condensate pipeline isolation valve 23 of the second unit; under the unit startup condition, the condensate from the outlet of the first-stage preheater is gathered in the main pipe, and then flows to the condenser through the condenser isolation valve 28 of the first unit and the condenser isolation valve 27 of the second unit, thereby ensuring the safety and stability of the secondary circuit condensate system under different operating conditions.

[0075] The first unit condensate isolation valve A5, the second unit condensate isolation valve A6, the second unit condensate isolation valve B7, the first unit condensate isolation valve B8, the second unit condensate isolation valve C9, the first unit condensate isolation valve C10, the first unit condensate isolation valve D11, the second unit condensate isolation valve D12 can be controlled to open and close locally and in the control room;

[0076] When the electric isolation valve of the heating main steam pipeline system of the first unit is fully opened, the first unit condensate isolation valve A5, the first unit condensate isolation valve B8, the first unit condensate isolation valve C10, and the first unit condensate isolation valve D11 on the condensate pipeline of the first unit are interlocked and opened; at the same time, the second unit condensate isolation valve A6, the second unit condensate isolation valve B7, the second unit condensate isolation valve C9, and the second unit condensate isolation valve D12 on the condensate pipeline of the second unit are interlocked and closed;

[0077] When the electric isolation valve of the heating main steam pipeline system of the first unit is fully closed, the first unit condensate isolation valve A5, the first unit condensate isolation valve B8, the first unit condensate isolation valve C10, and the first unit condensate isolation valve D11 on the condensate pipeline of the first unit are chained and closed to ensure that the main steam condensate of the first unit flows back to the first unit to avoid mixing of the secondary circuit media of the two units.

[0078] When the electric isolation valve of the heating main steam pipeline system of the second unit is fully opened, the second unit condensate isolation valve A6, the second unit condensate isolation valve B7, the second unit condensate isolation valve C9, and the second unit condensate isolation valve D12 on the condensate pipeline of the second unit are interlocked and opened; at the same time, the first unit condensate isolation valve A5, the first unit condensate isolation valve B8, the first unit condensate isolation valve C10, and the first unit condensate isolation valve D11 on the condensate pipeline of the first unit are interlocked and closed;

[0079] When the electric isolation valve of the heating main steam pipeline system of the second unit is fully closed, the second unit condensate isolation valve A6, the second unit condensate isolation valve B7, the second unit condensate isolation valve C9, and the second unit condensate isolation valve D12 on the condensate pipeline of the second unit are chained and closed to ensure that the main steam condensate of the second unit flows back to the second unit to avoid mixing of the secondary circuit media of the two units.

[0080] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0081] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. Nuclear power plant industrial steam supply condensate return system, characterized by: include: The first condensate jelly pipe has a rear end connected to the first unit condensate main pipeline and the first unit condenser through two branches; The rear end of the second condensate jelly pipe is connected to the condensate main pipeline of the second unit and the condenser of the second unit through two branches; Two primary feedwater preheating systems are connected to the front end of the first condensate jelly pipe through the condensate pipe at the rear end thereof, and the condensate collected after heat exchange of the steam conversion equipment is transported to the condensate jelly pipe; Two primary feedwater preheating systems are connected to the front end of the second condensate jelly pipe through the condensate pipe at the rear end thereof, and the condensate collected after heat exchange of the steam conversion equipment is transported to the condensate jelly pipe; Multiple flow meters are connected in parallel on each condensate jellyfish tube. The branch connected to the main condensate pipeline of the first unit is provided with an isolation valve for the main condensate pipeline of the first unit; the branch connected to the condenser of the first unit is provided with an isolation valve for the condenser of the first unit; The branch line connected to the condensate main pipeline of the two units is provided with an isolation valve for the main condensate pipeline of the second unit; the branch line connected to the condenser of the second unit is provided with an isolation valve for the condenser of the second unit.

2. The nuclear power plant industrial steam supply condensate return system according to claim 1, characterized in that: The two primary feedwater preheating systems are connected to the front end of the first condensate water pipe through the first unit condensate water pipe and the second unit condensate water pipe respectively. The other two primary feedwater preheating systems are connected to the front end of the second condensate main pipe through the condensate pipe of the first unit and the condensate pipe of the second unit respectively. A first electric isolation valve is provided on the condensate pipeline of each first unit; a second electric isolation valve is provided on the condensate pipeline of each second unit.

3. The nuclear power plant industrial steam supply condensate return system according to claim 1, characterized in that: The first condensation jellyfish tube is provided with a temperature measuring device and a pressure measuring device; The second condensation jellyfish tube is provided with a temperature measuring device and a pressure measuring device.

4. The nuclear power plant industrial steam supply condensate return system according to claim 1, characterized in that: There are at least three flow meters.

5. A method for controlling the return of condensate from industrial steam supply in a nuclear power plant, characterized in that: include: When the unit is operating normally, the condensate after heat exchange in the steam conversion equipment flows back to the main condensate pipeline of the unit through the condensate dam pipe; Under the unit startup condition, the condensate after heat exchange in the steam conversion equipment flows to the condenser through the condensate jellyfish pipe.

6. The method for controlling the return of condensate from industrial steam supply in a nuclear power plant according to claim 5, characterized in that: When the unit is operating normally, The isolation valve of the main condensate pipeline of the first unit and the isolation valve of the main condensate pipeline of the second unit are opened, and the isolation valve of the condenser of the first unit and the isolation valve of the condenser of the second unit are closed; When the electric isolation valve of the heating main steam pipeline system of the first unit is fully open or fully closed, the electric isolation valve on the condensate pipeline of the first unit is opened or closed in linkage, and the electric isolation valve on the condensate pipeline of the second unit is closed or opened at the same time; When the electric isolation valve of the heating main steam pipeline system of the second unit is fully open or fully closed, the electric isolation valve on the condensate pipeline of the second unit is opened or closed in conjunction, and the electric isolation valve on the condensate pipeline of the first unit is closed or opened at the same time.

7. The method for controlling the return of condensate from industrial steam supply in a nuclear power plant according to claim 5, characterized in that: Under the unit startup condition, the main condensate pipeline isolation valve of the first unit and the main condensate pipeline isolation valve of the second unit are closed, and the condenser isolation valve of the first unit and the condenser isolation valve of the second unit are opened, so that the condensate flows to the condenser through the condensate jellyfish pipe.

8. The method for controlling the return of condensate from industrial steam supply in a nuclear power plant according to claim 5, characterized in that: Also includes: When the observed liquid level of the evaporator is high, the isolation valve for the condenser of the first unit and the isolation valve for the condenser of the second unit will be opened automatically; When the conventional island deaerator is at a high water level, the isolation valve for the condenser of the first unit and the isolation valve for the condenser of the second unit are automatically opened.

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