Desalted water replenishing system for power plant

Abstract

The utility model discloses a power plant demineralized water replenishing system, which belongs to the field of power plant pipeline design and comprises an original water replenishing system and an original vacuum pump cooling system, a demineralized water inlet pipeline of a vacuum pump is provided with a branch port, and the branch port is connected with a demineralized water source after being converged with a pipeline of the original water replenishing system through a connecting pipe I; an isolating valve IV, a regulating valve I and an isolating valve V are sequentially arranged on the connecting pipe I; a branch opening is formed in the position, in front of the isolating valve III, of an outlet pipeline of the gas-liquid separation tank, the branch opening is connected with a water supplementing point after being converged with a pipeline of an original water supplementing system through a connecting pipe II, an isolating valve VI is arranged on the connecting pipe II, and a check valve is arranged in front of the branch opening of a demineralized water outlet pipeline of the heat exchanger. According to the utility model, the working temperature of the vacuum pump is reduced, the working effect of the vacuum pump is further improved, and meanwhile, the temperature of demineralized water entering a water replenishing point is improved under the condition that a heating device is not independently added, so that the efficiency of the water replenishing point device is improved.

Description

Technical Field

[0001] The utility model relates to a water replenishment system, in particular to a demineralized water replenishment system for a power plant, and belongs to the field of power plant pipeline design. Background Art

[0002] As more and more thermal power plants begin to increase their industrial steam load year by year, it brings a series of benefits to the power plants. However, since the condensate water after the steam is discharged to the user side is often not recycled, the power plants need to add a desalted water replenishment point 3 in the condensate system. The original replenishment system is as follows: Figure 2 As shown, the desalted water source 1 and the water replenishment point 3 are directly connected through a pipeline. An isolation valve I2 is provided on the pipeline. The desalted water is directly replenished from the desalted water source 1 to the water replenishment point 3 to maintain the steam-water balance of the thermal system. Except for some back-pressure extraction steam units, the water replenishment point 3 is selected in the deaerator, and most others are selected on the condenser.

[0003] However, the demineralized water comes from the water production system, and its temperature is lower than the operating temperature inside the condenser or deaerator. Directly replenishing the demineralized water from source 1 to the water replenishment point 3 will have a certain impact on the heat exchange, vacuum level, oxygen removal efficiency, and deoxygenation effect of the condenser or deaerator, thereby affecting the unit efficiency. Therefore, in the existing technology, it is necessary to add a heating device to the demineralized water replenishment system to increase the temperature of the demineralized water. However, adding a separate heating device not only increases the power plant investment but also increases energy consumption, affecting the power plant efficiency.

[0004] There are many devices in the power plant that need to be cooled, and the vacuum pump 8 is one of them. In the conventional vacuum pump cooling system 21, the working fluid of the vacuum pump 8 is desalted water. The original vacuum pump cooling system 21 structure is as follows Figure 3 As shown: the original vacuum pump cooling system 21 includes a vacuum pump 8 provided with a desalted water inlet and inlet, and a heat exchanger 7 provided with a desalted water inlet and inlet and a cooling water inlet and inlet respectively and capable of heat exchange. The desalted water outlet of the vacuum pump 8 is connected to the desalted water inlet of the gas-liquid separation tank 20 through a pipeline, the desalted water outlet of the gas-liquid separation tank 20 is connected to the desalted water inlet of the heat exchanger 7 through a pipeline, and the desalted water outlet of the heat exchanger 7 is connected to the desalted water inlet of the vacuum pump 8 through a pipeline, forming a closed cycle; the cooling water inlet of the heat exchanger 7 is connected to the cooling water source through a pipeline with an isolation valve II6, and the cooling water outlet is connected to the hot water tank 5 through a pipeline with an isolation valve VIII22.

[0005] However, in summer, due to the increase in the temperature of the open cooling water, the cooling force of the desalted water in the vacuum pump 8 is insufficient, resulting in a poor cooling effect of the desalted water of the vacuum pump 8. The actual operating temperature of the vacuum pump 8 is higher than the rated temperature, resulting in insufficient output of the vacuum pump 8, cavitation scaling, and a decrease in the vacuum degree of the deaerator or condenser, and a reduction in the unit output, which seriously affects the economic efficiency of the power plant. Utility Model Content

[0006] In order to solve the above technical problems, the utility model provides a desalted water replenishment system for a power plant, which reduces the operating temperature of the vacuum pump and thus improves the working effect of the vacuum pump; at the same time, the temperature of the desalted water entering the replenishment point is increased without adding a separate heating device, thereby improving the efficiency of the replenishment point device.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A desalted water replenishment system for a power plant includes an original water replenishment system and an original vacuum pump cooling system. The original water replenishment system connects the desalted water source and the water replenishment point through a pipeline with an isolation valve I; the original vacuum pump cooling system includes a vacuum pump provided with a desalted water inlet and inlet, and a heat exchanger provided with a desalted water inlet and inlet and a cooling water inlet and inlet and capable of heat exchange. The desalted water outlet of the vacuum pump is connected to the desalted water inlet of a gas-liquid separation tank through a pipeline, the desalted water outlet of the gas-liquid separation tank is connected to the desalted water inlet of the heat exchanger through a pipeline with an isolation valve III, and the desalted water outlet of the heat exchanger is connected to the desalted water inlet of the vacuum pump through a pipeline, forming a closed circulation, the cooling water inlet of the heat exchanger is connected to the cooling water source through a pipeline, and the cooling water outlet is connected to the hot water pool through a pipeline; a branch port is provided on the desalted water inlet pipeline of the vacuum pump, which is connected to the desalted water source after merging with the pipeline of the original water supply system through a connecting pipe I, and an isolation valve IV, a regulating valve I and an isolation valve V are sequentially provided on the connecting pipe I; a branch port is provided at the position before the isolation valve III of the outlet pipeline of the gas-liquid separation tank, which is connected to the water supply point after merging with the pipeline of the original water supply system through a connecting pipe II, and an isolation valve VI is provided on the connecting pipe II, and a check valve is provided at the position before the branch port of the desalted water outlet pipeline of the heat exchanger.

[0009] A further improvement of the technical solution of the present invention is that: a plurality of the original vacuum pump cooling systems are connected in parallel, and an isolation valve is provided on the connecting pipe I and the connecting pipe II of each vacuum pump cooling system.

[0010] A further improvement of the technical solution of the present utility model is that a vacuum isolation valve is further provided on the connecting pipe II.

[0011] A further improvement of the technical solution of the present utility model is that the valve group consisting of the isolation valve III, the regulating valve I and the isolation valve IV is connected in parallel with the regulating valve II.

[0012] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is:

[0013] When the system of the utility model is working, the isolation valve II and the isolation valve VIII are cut off, and the closed desalted water and open cooling water are no longer used to cool the vacuum pump. Only the open desalted water is used to cool the vacuum pump, which saves energy and has a better cooling effect, thereby improving the working efficiency of the vacuum pump; and the desalted water used to cool the vacuum pump is introduced into the water replenishing point, thereby increasing the water temperature of the desalted water without adding a heating device, and the working efficiency of the water replenishing point device becomes higher.

[0014] The utility model has multiple original vacuum pump cooling systems connected in parallel, and an isolation valve is provided on the connecting pipe I and the connecting pipe II of each vacuum pump cooling system, which can isolate the non-operating vacuum pump from the system, thereby improving the flexibility of the system; when the heated desalted water provided by the operating vacuum pump is insufficient to meet the amount of desalted water required by the water replenishment system, the isolation valve I is opened, and the opening of the regulating valve I is adjusted to provide a sufficient amount of desalted water for the water replenishment system.

[0015] The connecting pipe II of the utility model is also provided with a vacuum isolation valve, which is used to protect the vacuum environment of the water replenishment point. The heat generated by the vacuum pump when working can be more effectively used to increase the temperature of the desalted water, and the energy utilization rate is higher.

[0016] The connecting pipe I of the utility model is further provided with a regulating valve II connected in parallel with the valve group consisting of the isolation valve IV, the regulating valve I, and the isolation valve V. When the regulating valve I fails and needs to be repaired, the isolation valves IV and the isolation valve V on both sides of the regulating valve can be cut off, and the regulating valve II can be opened to ensure the normal operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the pipe connection structure of the utility model;

[0018] Figure 2 This is a schematic diagram of the pipe connection structure of the original water supply system;

[0019] Figure 3 This is a schematic diagram of the pipe connection structure of the original vacuum pump cooling system;

[0020] Figure 4 This is a schematic diagram of the pipeline connection structure of an embodiment of the present utility model.

[0021] Among them, 1. Desalted water source; 2. Isolation valve I; 3. Water replenishment point; 4. Cooling water source; 5. Hot water tank; 6. Isolation valve II; 7. Heat exchanger; 8. Vacuum pump; 9. Check valve; 10. Vacuum isolation valve; 11. Isolation valve III; 12. Isolation valve IV; 13. Control valve I; 14. Isolation valve V; 15. Control valve II; 16. Isolation valve VI; 17. Isolation valve VII; 18. Connecting pipe I; 19. Connecting pipe II; 20. Gas-liquid separation tank; 21. Original vacuum pump cooling system; 22. Isolation valve VIII. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below with reference to the embodiments:

[0023] like Figure 1 As shown, the original water supply system includes a desalted water source 1 and a water supply point 3 connected by a pipeline, and an isolation valve I2 is also provided between the two; Figure 2 As shown, the original vacuum pump cooling system 21 includes a vacuum pump 8 provided with a desalted water inlet and inlet, and a heat exchanger 7 provided with a desalted water inlet and inlet and a cooling water inlet and inlet respectively and capable of heat exchange. The desalted water outlet of the vacuum pump 8 is connected to the desalted water inlet of the gas-liquid separation tank 20 through a pipeline, the desalted water outlet of the gas-liquid separation tank 20 is connected to the desalted water inlet of the heat exchanger 7 through a pipeline with an isolation valve III11, the desalted water outlet of the heat exchanger 7 is connected to the desalted water inlet of the vacuum pump 8 through a pipeline, forming a closed cycle, the cooling water inlet of the heat exchanger 7 is connected to the cooling water source 4 through a pipeline with an isolation valve II6, and the cooling water outlet is connected to the hot water tank 5 through a pipeline with an isolation valve VIII22.

[0024] like Figure 3 As shown, a branch port is provided on the desalted water inlet pipe of the vacuum pump of the present invention, which is connected to the desalted water source 1 after merging with the pipe of the original water supply system through a connecting pipe I18, and an isolation valve IV12, a regulating valve I13 and an isolation valve V14 are sequentially provided on the connecting pipe I18; a branch port is provided at the position before the isolation valve III11 of the outlet pipe of the gas-liquid separation tank 20, which is connected to the water supply point 3 after merging with the pipe of the original water supply system through a connecting pipe II19, and an isolation valve VI16 is provided on the connecting pipe II19, and a check valve 9 is provided at the position before the branch port of the desalted water outlet pipe of the heat exchanger 7.

[0025] When the utility model is working, the isolation valve II6, the isolation valve VIII 22 and the check valve 9 are cut off, the isolation valve I2, the isolation valve III12, the isolation valve V14 and the isolation valve VI16 are opened, and the opening of the regulating valve I13 is adjusted according to the actual situation of the vacuum pump 8 and the gas-liquid separator 20, so that the whole system works normally; the vacuum pump 8 is no longer cooled by the method of combining internal circulation desalted water with open cooling water, and only the open desalted water is used to cool the vacuum pump 8, which saves energy and has a better cooling effect, thereby improving the working efficiency of the vacuum pump 8; and the desalted water that has cooled the vacuum pump 8 is introduced into the water replenishment point 3, and the temperature of the desalted water entering the water replenishment point 3 is increased without adding a separate heating device. Due to the increase in the water temperature of the desalted water, the working efficiency of the condenser or deaerator is improved.

[0026] In another embodiment of the present invention, there are three original vacuum pump cooling systems 21, and an isolation valve is provided on the connecting pipe I18 and the connecting pipe II19 of each vacuum pump cooling system 21, which can isolate the non-operating vacuum pump from the system, thereby improving the overall flexibility of the system.

[0027] A vacuum isolation valve 10 is also provided on the connecting pipe II19. The vacuum isolation valve 10 is used to protect the vacuum environment of the water replenishment point 3. The heat generated by the vacuum pump 8 when working can be more effectively used to increase the temperature of the desalted water, thereby improving energy utilization.

[0028] The valve group consisting of the isolation valve III12, the regulating valve I13, and the isolation valve IV14 is connected in parallel with the regulating valve II15. When the regulating valve I13 fails and needs to be repaired, the isolation valve III12 and the isolation valve IV14 on both sides of the regulating valve I13 can be cut off, and the regulating valve II15 can be opened to ensure the normal operation of the system.

Claims

1. A desalted water replenishment system for a power plant, comprising an original replenishment water system and an original vacuum pump cooling system (21), wherein the original replenishment water system connects a desalted water source (1) and a replenishment point (3) via a pipeline with an isolation valve I (2); the original vacuum pump cooling system (21) comprises a vacuum pump (8) provided with a desalted water inlet and inlet, and a heat exchanger (7) provided with a desalted water inlet and inlet and a cooling water inlet and inlet respectively and capable of heat exchange, the desalted water outlet of the vacuum pump (8) being connected to the desalted water inlet of a gas-liquid separation tank (20) via a pipeline, the desalted water outlet of the gas-liquid separation tank (20) being connected to the desalted water inlet of the heat exchanger (7) via a pipeline with an isolation valve III (11), the desalted water outlet of the heat exchanger (7) being connected to the desalted water inlet of the vacuum pump (8) via a pipeline, forming a closed cycle, the cooling water inlet of the heat exchanger (7) being connected to a cooling water source (4) via a pipeline, and the cooling water outlet being connected to a hot water tank (5) via a pipeline; and characterized in that: A branch port is provided on the desalted water inlet pipe of the vacuum pump (8), which is connected to the desalted water source (1) after merging with the pipe of the original water supply system through a connecting pipe I (18), and an isolation valve IV (12), a regulating valve I (13) and an isolation valve V (14) are sequentially provided on the connecting pipe I (18); a branch port is provided at a position before the isolation valve III (11) of the outlet pipe of the gas-liquid separation tank (20), which is connected to the water supply point (3) after merging with the pipe of the original water supply system through a connecting pipe II (19), and an isolation valve VI (16) is provided on the connecting pipe II (19). A check valve (9) is provided at a position before the branch port of the desalted water outlet pipe of the heat exchanger (7).

2. A desalted water replenishment system for a power plant according to claim 1, characterized in that: The original vacuum pump cooling system (21) is connected in parallel with multiple ones, and an isolation valve is provided on the connecting pipe I (18) and the connecting pipe II (19) of each vacuum pump cooling system (21).

3. The desalted water replenishment system for a power plant according to claim 1, characterized in that: The connecting pipe II (19) is also provided with a vacuum isolation valve (10).

4. The desalted water replenishment system for a power plant according to claim 1, characterized in that: The valve group consisting of the isolation valve III (11), the regulating valve I (13) and the isolation valve IV (12) is connected in parallel with the regulating valve II (15).

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