Condenser water supplementing system

Abstract

The utility model relates to the technical field of condensers, in particular to a condenser water replenishing system which comprises a condenser water replenishing pipeline (4), a condenser (2), a heat supply network water return pipeline (5) and a water-water heat exchanger (1). A water outlet of the heat supply network water return pipeline (5) is connected with a shell side water inlet of the water-water heat exchanger (1); a water outlet of the condenser water replenishing pipeline (4) is connected with a pipe side water inlet of the water-water heat exchanger (1); a pipe side water outlet of the water-water heat exchanger (1) is connected with a throat part of the condenser (2); heat supply network return water on the shell side of the water-water heat exchanger (1) exchanges heat with condenser replenished water on the pipe side of the water-water heat exchanger (1) so as to heat the condenser replenished water. According to the water supplementing system for the condenser, the temperature of supplemented water of the condenser is increased through heat supply network return water, precipitation of the dissolved oxygen effect is enhanced, the dissolved oxygen content in condensed water is reduced, and corrosion to pipelines and equipment is greatly reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of condensers, in particular to a condenser water replenishment system. Background Art

[0002] The condensate of the condenser has a high dissolved oxygen content, which can easily aggravate the corrosion of pipelines and equipment and have a great impact on the service life of the equipment. In addition, when the dissolved oxygen content at the outlet of the condensate pump is high, the dissolved oxygen content at the inlet of the deaerator increases accordingly, and the dissolved oxygen content at the outlet of the deaerator also increases accordingly. If the dissolved oxygen content of the condensate is not reduced in time, when the dissolved oxygen content continues to increase, the dissolved oxygen content at the outlet of the deaerator may exceed the standard value, causing the dissolved oxygen content of the feed water to be high, which will aggravate the corrosion of the boiler and the steam turbine, reduce the service life of the boiler and the steam turbine, and cause huge hidden dangers to the safe operation of the equipment.

[0003] Therefore, there is an urgent need for a system that can reduce the dissolved oxygen content in the condensate of the condenser. Utility Model Content

[0004] The purpose of the utility model is to overcome the above-mentioned defects and thus provide a condenser water replenishment system.

[0005] In order to solve the above technical problems, the condenser water supply system provided by the technical solution of the utility model includes: a condenser water supply pipeline 4, a condenser 2, a heat network return water pipeline 5 and a water-water heat exchanger 1; wherein,

[0006] The water outlet of the heat network return pipe 5 is connected to the water inlet on the shell side of the water-water heat exchanger 1;

[0007] The water outlet of the condenser water supply pipeline 4 is connected to the water inlet of the water-water heat exchanger 1 on the tube side; the water outlet of the water-water heat exchanger 1 on the tube side is connected to the throat of the condenser 2;

[0008] The heat network return water on the shell side of the water-water heat exchanger 1 is heat-exchanged with the condenser feed water on the tube side of the water-water heat exchanger 1 to heat the condenser feed water.

[0009] Preferably, the throat of the condenser 2 is provided with an atomizing spray component, and the heated condenser makeup water is atomized in the throat of the condenser 2 through the atomizing spray component.

[0010] Preferably, the condenser water replenishment system also includes: a drain empty container 3, which is respectively connected to the shell side water outlet of the water-water heat exchanger 1 and the condenser 2; the heat network return water after heat exchange is depressurized by the drain empty container 3 and then flows into the hot well of the condenser 2 to mix with the condensate.

[0011] Preferably, the water-water heat exchanger 1 is a water-water surface heat exchanger.

[0012] Compared with the prior art, the utility model has the advantage that the condenser feed water system of the utility model uses the return water from the heat network to heat the condenser feed water, which can reduce the return water temperature of the heat network, make full use of the waste heat of the return water from the heat network, and improve the thermal efficiency of the unit. The heated condenser feed water is combined with the atomizing spray parts to greatly increase the atomization effect in the condenser, strengthen the precipitation of the dissolved oxygen effect, reduce the dissolved oxygen content in the condensate, and greatly reduce the corrosion to the pipeline and equipment. Reduce the corrosion to the boiler and the steam turbine, increase the service life of the boiler and the steam turbine, and at the same time improve the safety of the water supply equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the condenser water replenishment system provided by the utility model.

[0014] Figure ID

[0015] 1. Water-water heat exchanger 2. Condenser 3. Drain expansion tank

[0016] 4. Condenser water supply pipeline 5. Heat network return water pipeline DETAILED DESCRIPTION

[0017] This embodiment takes a steam turbine as an example, analyzes the condenser 2 of the steam turbine, and finds that the dissolved oxygen content in the condensate is high, which aggravates the corrosion of pipelines and equipment. The steam turbine is a steam turbine of a power plant unit put into operation on July 31, 2016. The steam turbine is a high-efficiency ultra-supercritical, one-stage intermediate reheat, four-cylinder four-exhaust, single-shaft, double back pressure, condensing steam turbine produced by Shanghai Electric Group Co., Ltd., with parameters of 28MPa / 600℃ / 620℃. The generator uses a water-hydrogen-hydrogen cooling generator manufactured by Shanghai Electric Group with Siemens technology. The current situation of high dissolved oxygen in condensate Since September 2017, the oxygen content at the outlet of the condensate pump is relatively high. According to the test data, the average dissolved oxygen from September to now is about 60μg / L, which exceeds the provisions of Article 6.9.1 of JB / T10085 "Steam Turbine Surface Condenser". On February 13, 2019, the dissolved oxygen detection values ​​of Unit 1 exceeded the standard values.

[0018] Dissolved oxygen detection value of Unit 1 of the power plant in winter:

[0019]

[0020] The applicant found that due to the large amount of condensate make-up water in Unit 1 (the normal make-up rate is no more than 1%, and the make-up rate of this unit was above 1.4% from October 2018 to November 2018), and the make-up water was not atomized after entering condenser 2, it could not fully contact with the exhaust steam of the low-pressure cylinder, which could easily cause poor oxygen precipitation effect, and thus make the oxygen content at the outlet of the condensate pump higher.

[0021] Therefore, in this embodiment, an atomizing spray component is installed at the throat of the condenser 2, so that the make-up water can be diffused into water mist inside the neck of the condenser 2. The atomized make-up water can fully contact with the exhaust steam of the turbine, thereby increasing the temperature of the make-up water, causing the dissolved oxygen in the make-up water to precipitate and then be extracted by the exhaust device, thereby reducing the oxygen content at the outlet of the condensate pump.

[0022] The atomizing spray component is a spray head or a nozzle in a broad sense. In this embodiment, the atomizing spray component adopts a spray head that can rotate automatically. The spray is umbrella-shaped and the atomizing effect is better.

[0023] The condensate replenishment water of the unit comes from desalted water with a large flow rate (about 25t / h). By using an atomizing spray component (nozzle), the condensate replenishment water can be diffused into water mist inside the neck of the condenser 2, increasing the contact area with the turbine exhaust steam and enhancing the dissolved oxygen precipitation effect. In summer, this solution is used because the temperature of the desalted water is higher and the dissolved oxygen dilution effect is better.

[0024] However, in winter, the temperature of desalted water is low, which has a greater impact on the dissolved oxygen precipitation effect. Therefore, in order to adapt to the change of desalted water temperature throughout the year, in this embodiment, in addition to adding a nozzle at the throat of the condenser 2, a water-water heat exchanger 1 is added to heat the condenser feed water, increase the temperature of desalted water, improve the dissolved oxygen effect, and then reduce the oxygen content of the condensate to within the standard range.

[0025] like Figure 1 As shown, this embodiment is modified on the original steam turbine system, and a water-water heat exchanger 1, a water replenishment pressure reducing device (atomizing spray part), valves and pipeline accessories are added.

[0026] The water outlet of the heat network return pipe 5 is connected to the water inlet on the shell side of the water-water heat exchanger 1;

[0027] The drain empty container 3 is connected to the shell side water outlet of the water-water heat exchanger 1 and the condenser 2 respectively;

[0028] The water outlet of the condenser water supply pipeline 4 is connected to the water inlet of the water-water heat exchanger 1 on the tube side; the water outlet of the water-water heat exchanger 1 on the tube side is connected to the throat of the condenser 2;

[0029] The heat network return water on the shell side of the water-water heat exchanger 1 exchanges heat with the condenser feed water on the tube side of the water-water heat exchanger 1 to heat the condenser feed water.

[0030] The heated hot condenser feed water is atomized at the throat of the condenser 2 through the atomizing spray part. The return water from the heat network after heat exchange is depressurized by the drain empty container 3 and then flows into the hot well of the condenser 2 to mix with the condensate.

[0031] In this embodiment, the water-water heat exchanger 1 is a water-water surface heat exchanger.

[0032] The system layout after equipment performance improvement is as follows Figure 1 As shown in the figure, the heat network return water pipeline has been modified. The heat network return water first enters the shell side of the water-water heat exchanger 1, and after releasing the heat, it enters the high-pressure side of the drain expansion tank 3, and finally flows into the condenser 2; at the same time, the condensate feed water pipeline has been modified. Normal condensate feed water enters the tube side of the water-water heat exchanger 1, and after being heated, it enters the low-pressure side of the condenser 2, and is atomized inside the condenser 2 through the pressure reducing device.

[0033] In this embodiment, the technical characteristics of the water-to-water heat exchanger used are as follows:

[0034]

[0035] In this embodiment, the specific specifications and quantities of the installed water supply valve, drain valve, elbow, pipe, channel steel and other materials are shown in the following table:

[0036] Equipment Details Specifications quantity unit Water supply valve DN80 PN2.5 4 tower Steam Trap DN32 PN2.5 6 tower pipeline 89×4.5 80 rice pipeline 273×10 20 rice elbow 89×4.5 30 Item elbow 273×6.5 8 Item pipeline 32×4 30 rice elbow 32×4 10 Item Channel Steel No. 8 10 rice

[0037] It is worth noting that how to install the atomizing spray part to the throat of the condenser 2, how to connect the heat network return pipe to the water-water heat exchanger 1, and how to connect the condensate feed water pipe to the water-water heat exchanger 1 are technical means well known to those skilled in the art. The feed water valve, drain valve, elbow, pipe, channel steel and other materials used above are only used to transform the steam turbine in this embodiment. The condenser feed water system provided in this embodiment can also be used in other steam turbines and boilers. Those skilled in the art can select corresponding feed water valves, drain valves, elbows, pipes, channel steel and other materials according to the structure of the specific steam turbine and boiler, so that the condenser feed water system provided in this embodiment can be installed therein.

[0038] From the above specific description of the utility model, it can be seen that the condenser water supply system proposed by the utility model uses the return water of the heat network to enter the shell side of the water-water heat exchanger 1, heats the condenser water supply in the tube side, and then discharges it into the drain expansion tank 3, and finally discharges it into the condenser 2. This design can reduce the return water temperature of the heat network, make full use of the waste heat of the return water of the heat network, and improve the thermal efficiency of the unit.

[0039] The temperature is low in winter. If only the cooling and pressure reducing device composed of nozzles is used, the dissolved oxygen precipitation effect is not good. After using the water-to-water heat exchanger 1, the condensate replenishment temperature of desalted water can be increased to 30°C, which can greatly increase the atomization effect in the condenser 2 and enhance the precipitation of dissolved oxygen. Now the dissolved oxygen content of Unit 1 is kept below 15μg / L all year round, which is much higher than the standard value.

[0040] The reduction of dissolved oxygen in condensate can greatly reduce corrosion to pipelines and equipment, reduce the corrosion effect on boilers and steam turbines, increase the service life of boilers and steam turbines, and at the same time improve the safety of water supply equipment.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model and are not intended to limit it. Although the utility model is described in detail with reference to the embodiments, a person skilled in the art should understand that any modification or equivalent replacement of the technical solution of the utility model does not deviate from the spirit and scope of the technical solution of the utility model, and should be included in the scope of the claims of the utility model.

Claims

1. A condenser water supply system, include: The condenser water supply pipeline (4), the condenser (2) and the heat network return water pipeline (5) are characterized in that they also include: a water-water heat exchanger (1); wherein, The water outlet of the heat network return water pipeline (5) is connected to the shell side water inlet of the water-water heat exchanger (1); The water outlet of the condenser water supply pipeline (4) is connected to the water inlet on the tube side of the water-water heat exchanger (1); the water outlet on the tube side of the water-water heat exchanger (1) is connected to the throat of the condenser (2); The heat network return water on the shell side of the water-water heat exchanger (1) exchanges heat with the condenser feed water on the tube side of the water-water heat exchanger (1) to heat the condenser feed water.

2. The condenser water supply system according to claim 1, It is characterized in that The throat of the condenser (2) is provided with an atomizing spray component, and the heated condenser makeup water is atomized in the throat of the condenser (2) through the atomizing spray component.

3. The condenser water supply system according to claim 1, It is characterized in that Also includes: A drain empty container (3), the drain empty container (3) is respectively connected to the shell side water outlet of the water-water heat exchanger (1) and the condenser (2); the return water from the heat network after heat exchange is depressurized by the drain empty container (3) and then flows into the hot well of the condenser (2) to mix with the condensate.

4. The condenser water supply system according to claim 1, It is characterized in that The water-water heat exchanger (1) is a water-water surface heat exchanger.

Images