Drain flash tank pressure maintaining device

Abstract

The utility model belongs to the technical field of self-powered equipment of a thermal power plant, and relates to a drain flash tank pressure maintaining device which comprises a steam turbine, the rear side of the steam turbine is connected with a steam condenser, the steam condenser is connected with a steam exhaust pipe, an exhaust pipe is connected to a drain flash tank, a water level gauge is arranged in the drain flash tank, and the drain flash tank is connected with a drain main pipe. A drainage inlet pipe is arranged on the drainage main pipe, a drainage outlet pipe is arranged at the bottom of the drainage flash tank, a drainage valve and an electromagnetic valve are arranged on the drainage outlet pipe, and the drainage outlet pipe is connected to a condenser. According to the utility model, the steam side volume of the condenser can be directly reduced, the workload of the vacuum pump is reduced, the vacuum degree of the condenser is improved, the pressure is increased after all levels of drainage, and the suction to the drainage pipeline caused by the too low pressure in the drainage flash tank is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of self-use electric equipment in thermal power plants, and in particular relates to a pressure maintaining device for a hydrophobic expansion tank. Background Art

[0002] In a thermal power plant, when the turbine body, steam pipes and steam extraction pipes are restarted or shut down or during normal operation, they will be affected by temperature and load changes, and steam will produce condensate. This condensate will have an impact on the unit and the pipes. In order to ensure the safe operation of the unit, it is necessary to add drain pipes in various places to drain the water in the pipes in time to ensure the good quality of the steam in the pipes.

[0003] Due to the excessive number of drain pipes, a drain main pipe is set up to evenly distribute all drains on the drain main pipe according to the pressure. Finally, the drain main pipe is discharged to the drain expansion tank to expand the steam and release the pressure, thereby reducing the drain pressure. Finally, the steam in the drain expansion tank is sucked into the condenser at the upper part with a pressure of -95KPa, and the condensed water is also discharged into the condenser from the lower drain pipe, thus realizing the full recovery of the drain.

[0004] In actual use, the following problems arise:

[0005] 1. There is no partition device between the exhaust pipe, drain pipe and condenser of the steam trap expansion tank, which causes the internal pressure of the steam trap expansion tank to be close to the condenser pressure. The extreme negative pressure causes the steam in front of the steam trap valve to be sucked in, resulting in unnecessary waste;

[0006] 2. There are many valves, flanges and welding points on each drain main pipe, which may cause steam leakage at any time due to poor sealing. The air leaking from each place is sucked into the condenser, causing the condenser vacuum to drop and the unit economic performance to decrease;

[0007] 3. Connecting the drain expansion tank is equivalent to increasing the space on the steam side of the condenser. The condenser vacuum decreases due to the increase in the steam side space, and the unit's economic performance decreases.

[0008] Therefore, a pressure maintaining device for a hydrophobic expansion tank is proposed. Utility Model Content

[0009] The utility model aims to provide a pressure-maintaining device for a hydrophobic expansion tank, which has the pressure-maintaining function of the hydrophobic expansion tank, solves the problem that in the prior art, the internal pressure of the hydrophobic expansion tank is close to the condenser pressure, the extreme negative pressure causes steam to be sucked in, and the condenser vacuum is reduced due to the increase of the steam side space, resulting in a decrease in the economic performance of the unit.

[0010] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is as follows: the utility model provides a pressure maintaining device for a hydrophobic expansion tank, including a steam turbine, a condenser is connected to the rear side of the steam turbine, an exhaust pipe is connected to the condenser, the exhaust pipe is connected to the hydrophobic expansion tank, a water level gauge is arranged inside the hydrophobic expansion tank, a hydrophobic main pipe is connected to the hydrophobic expansion tank, a hydrophobic inlet pipe is arranged on the hydrophobic main pipe, a hydrophobic outlet pipe is arranged at the bottom of the hydrophobic expansion tank, a hydrophobic valve and a solenoid valve are arranged on the hydrophobic outlet pipe, and the hydrophobic outlet pipe is connected to the condenser.

[0011] Preferably, the condenser is connected to a condensate pump.

[0012] Preferably, a steam inlet pipe is provided at the front side of the steam turbine, and a steam inlet valve is provided on the steam inlet pipe.

[0013] Preferably, a steam exhaust valve is provided on the exhaust pipe.

[0014] Preferably, a drain bypass is connected in parallel to the drain outlet pipe, and a bypass valve is provided on the drain bypass.

[0015] Preferably, the drain bypass is located at the front and rear sides of the drain valve and the solenoid valve at the connection position of the drain outlet pipe.

[0016] Compared with the prior art, the advantages and positive effects of the utility model are:

[0017] 1. The utility model can directly reduce the steam side volume of the condenser, reduce the workload of the vacuum pump, increase the vacuum of the condenser, increase the pressure after each level of drainage, and avoid the suction of the drainage pipeline caused by the low pressure inside the drainage expansion tank;

[0018] 2. The utility model has the function of maintaining pressure of the hydrophobic expansion tank, which solves the problem of the prior art without partition device, the internal pressure of the hydrophobic expansion tank is close to the condenser pressure, the extreme negative pressure causes steam to be sucked in, and the condenser vacuum is reduced due to the increase of the steam side space, resulting in a decrease in the unit's economic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor.

[0020] Figure 1 It is a structural schematic diagram of a pressure maintaining device of a hydrophobic expansion vessel;

[0021] In the above figure, 1. steam turbine, 2. steam inlet pipe, 3. steam inlet valve, 4. condenser, 5. condensate pump, 6. exhaust pipe, 7. drain expansion tank, 8. exhaust valve, 9. water level gauge, 10. drain main pipe, 11. drain inlet pipe, 12. drain outlet pipe, 13. drain valve, 14. solenoid valve, 15. drain bypass, 16. bypass valve. DETAILED DESCRIPTION

[0022] In order to more clearly understand the above-mentioned purpose, features and advantages of the utility model, the utility model is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0023] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein. Therefore, the present invention is not limited to the specific embodiments of the following disclosure.

[0024] Embodiment 1, as Figure 1 As shown, a pressure maintaining device for a hydrophobic expansion tank includes a steam turbine 1. The steam turbine 1 is used as a power generation device in a power plant to generate electricity using high-temperature steam. The rear side of the steam turbine 1 is connected to a condenser 4. The condenser 4 receives the steam discharged from the steam turbine 1 and condenses it into water, which can be recycled.

[0025] The condenser 4 is connected with an exhaust pipe 6, which is connected to a drain expansion tank 7. The drain expansion tank 7 is used to collect drain water, reduce pressure fluctuations, and remove condensed water. The exhaust pipe 6 discharges steam from the drain expansion tank 7 into the condenser 4. A water level gauge 9 is provided inside the drain expansion tank 7, which is used to monitor the water level in the drain expansion tank 7.

[0026] A trap main pipe 10 is connected to the trap expansion tank 7, and the trap main pipe 10 is connected to other pipes to receive and collect the trap. A trap inlet pipe 11 is provided on the trap main pipe 10, and external trap is input into the trap main pipe 10 through the trap inlet pipe 11 and flows into the trap expansion tank 7.

[0027] A drain outlet pipe 12 is provided at the bottom of the drain expansion tank 7, and a drain valve 13 and a solenoid valve 14 are provided on the drain outlet pipe 12. The drain valve 13 controls the flow of drain in the drain outlet pipe 12 to ensure smooth discharge, and the solenoid valve 14 can realize a certain degree of automatic operation by electromagnetically controlling the switch of the drain valve 13. The drain outlet pipe 12 is connected to the condenser 4, and the drain outlet pipe 12 connects the drain expansion tank 7 and the condenser 4, and is used to discharge the drain and condensed water in the drain expansion tank 7 to the condenser 4.

[0028] The following is a detailed description of the design of the above key components:

[0029] The condenser 4 is connected to a condensate pump 5. The design of the condensate pump 5 takes into account the discharge and recovery requirements of the condensate, ensuring that the condensate can be effectively pumped out of the condenser 4. The condensate pump 5 has a stable pumping capacity and high operating efficiency. At the same time, the maintenance of the condensate pump 5 must be considered to avoid blockage or other problems.

[0030] The steam turbine 1 is provided with a steam inlet pipe 2 at the front side, and a steam inlet valve 3 is provided on the steam inlet pipe 2. The steam turbine 1 receives external steam through the steam inlet pipe 2, and the steam inlet valve 3 is designed to have the function of controlling and regulating the steam flow in the steam pipe, so as to ensure that the steam turbine 1 can work normally under different loads and flexibly adjust the steam flow to ensure the safe operation of the steam turbine 1.

[0031] The exhaust pipe 6 is provided with an exhaust valve 8. The exhaust valve 8 can control the flow of steam and condensed water in the exhaust pipe 6 to ensure smooth discharge and adjustable flow of the exhaust pipe 6. The exhaust valve 8 should have the characteristics of leak-proof and high temperature resistance to ensure its safety, durability and reliability.

[0032] The drain outlet pipe 12 is connected in parallel with a drain bypass 15, which realizes the diversion of the drain outlet pipe 12, enhances the discharge capacity of the drain outlet pipe 12, and can also be used as a backup pipeline. The drain bypass 15 is provided with a bypass valve 16, which controls the opening and closing of the drain bypass 15, controls whether to enable the drain bypass 15, and adjusts the flow in the drain bypass 15.

[0033] The drain bypass 15 is located at the front and rear sides of the drain valve 13 and the solenoid valve 14 at the connection position of the drain outlet pipe 12. The drain valve 13 and the solenoid valve 14 can be bypassed through the drain bypass 15. When the drain valve 13 and the solenoid valve 14 are both closed, the water can be discharged through the drain bypass 15.

[0034] Embodiment 2, as shown in Embodiment 1, a pressure-maintaining device for a hydrophobic expansion tank, the hydrophobic water of each level first enters the hydrophobic main pipe 10 for confluence, the end of the hydrophobic main pipe 10 is connected to the hydrophobic expansion tank 7, and after the steam and condensed water enter the hydrophobic expansion tank 7, the pressure of the steam is reduced after the steam is expanded, and the steam is discharged into the condenser 4 from the top of the hydrophobic expansion tank 7. The condensed water entering the hydrophobic expansion tank 7 is discharged into the condenser 4 from the bottom hydrophobic outlet pipe 12, so as to ensure that the condensed water inside the hydrophobic expansion tank 7 is discharged in time.

[0035] A water level gauge 9 is provided in the steam expansion tank 7, and a steam exhaust valve 8 is provided in the steam exhaust pipe 6 of the steam expansion tank 7. During normal operation, the steam exhaust valve 8 is kept slightly open to ensure that the steam discharged into the steam expansion tank 7 can be discharged to the condenser 4 in time, and to ensure that there is a local negative pressure inside the steam expansion tank 7. The steam exhaust valve 13 of the steam outlet pipe 12 of the steam expansion tank 7 is kept at a 50% opening, and a solenoid valve 14 is provided behind the steam exhaust valve 13. The solenoid valve 14 senses the signal of the water level gauge 9 of the steam expansion tank 7. When the water level is higher than the set value, the solenoid valve 14 is actuated to open the valve to discharge the condensate inside the steam expansion tank 7. When the water level of the water level gauge 9 is lower than the set value, the solenoid valve 14 is closed or reduced to ensure that there is always a water level at the bottom of the steam expansion tank 7, and to avoid the steam leakage at each level affecting the vacuum of the condenser 4. When a large number of steam exhaust systems are put into operation during startup and shutdown, the bypass valve 16 of the steam exhaust pipe 6 and the steam exhaust bypass 15 can be opened to ensure normal operation inside the steam expansion tank 7.

[0036] The standard parts used in the utility model can all be purchased from the market, special-shaped parts can be customized according to the description in the specification and the drawings, the specific connection methods of each part adopt the conventional means such as mature bolts, rivets, welding, etc. in the prior art, the machinery, parts and equipment all adopt the conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here. The content not described in detail in this specification belongs to the prior art known to professional and technical personnel in this field.

[0037] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A pressure maintaining device for a hydrophobic expansion vessel, characterized in that: It comprises a steam turbine, the rear side of the steam turbine is connected to a condenser, the condenser is connected to an exhaust pipe, the exhaust pipe is connected to a drain expansion tank, a water level gauge is arranged inside the drain expansion tank, a drain main pipe is connected to the drain expansion tank, a drain inlet pipe is arranged on the drain main pipe, a drain outlet pipe is arranged at the bottom of the drain expansion tank, a drain valve and a solenoid valve are arranged on the drain outlet pipe, and the drain outlet pipe is connected to the condenser.

2. A hydrophobic expansion tank pressure maintaining device according to claim 1, characterized in that: The condenser is connected with a condensate pump.

3. A hydrophobic expansion tank pressure maintaining device according to claim 1, characterized in that: A steam inlet pipeline is arranged at the front side of the steam turbine, and a steam inlet valve is arranged on the steam inlet pipeline.

4. The pressure maintaining device for a hydrophobic expansion vessel according to claim 1, characterized in that: The exhaust pipe is provided with an exhaust valve.

5. The pressure maintaining device for a hydrophobic expansion vessel according to claim 1, characterized in that: A drain bypass is connected in parallel to the drain outlet pipe, and a bypass valve is arranged on the drain bypass.

6. A hydrophobic expansion tank pressure maintaining device according to claim 5, characterized in that: The connection position of the drain bypass at the drain outlet pipe is respectively located at the front and rear sides of the drain valve and the solenoid valve.

Images