Recovery system for high-temperature steam discharged by periodic discharge flash tank of thermal power plant

Abstract

The utility model relates to a high-temperature steam recovery system for a periodic-discharge flash tank of a thermal power plant, and is characterized in that at least two atomizing nozzles distributed along the vertical direction are fixedly arranged in a steam discharge pipe, and the atomizing nozzles are respectively connected with a cold water pipe extending out of the steam discharge pipe; the water inlet end of the drainage pipe is communicated with a water outlet in the bottom of the fixed-drainage flash tank, the water outlet end of the drainage pipe extends to the water storage tank, a direct drainage valve is installed on the drainage pipe, a bypass valve is arranged above the direct drainage valve, an inlet of the bypass valve is communicated with the drainage pipe on the upstream side of the direct drainage valve, and an outlet of the bypass valve is communicated with the water storage tank. An outlet of the bypass valve is communicated with a downstream side drainage pipe of the direct drainage valve, and the bypass valve is higher than a bottom water outlet of the fixed drainage flash tank in the height direction. According to the utility model, the atomizing nozzles are arranged in the steam discharge pipe to condense high-temperature steam, and the condensed water flows into the periodic discharge flash tank, so that the discharge loss of heat energy is reduced; through the bypass valve, water seal is formed at the bottom of the periodic discharge flash tank by using water in a pipeline, so that steam is prevented from being discharged from the bottom.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of fixed row expansion vessel of thermal power plant, especially to the discharge steam treatment of fixed row expansion vessel, specifically point to a kind of high-temperature steam recovery system of fixed row expansion vessel of thermal power plant. BACKGROUND

[0002] In the operation process of thermal power plant, fixed row expansion vessel (periodic blowdown expansion vessel) is used to handle high-temperature high-pressure wastewater and steam generated when boiler blows down. After the start of the boiler, boiler continuous drainage, boiler fixed row drainage, boiler accident drainage, boiler each drain, boiler water level gauge flushing drainage, steam turbine condensate drainage, steam turbine high pressure heater accident drainage, deaerator accident drainage and the like will all enter the expansion vessel, and the water temperature entering the expansion vessel is relatively high, and steam is discharged upward from the steam discharge pipe.

[0003] In the discharge process of the conventional fixed row expansion vessel, a large amount of high-temperature steam (steam emission) is generated, which is usually directly discharged into the atmosphere, causing energy waste and environmental pollution. With the increasing requirement of energy saving and emission reduction, how to effectively recycle this part of steam has become a problem to be solved by thermal power plants. CONTENT OF THE UTILITY MODEL

[0004] The utility model provides a kind of high-temperature steam recovery system of fixed row expansion vessel of thermal power plant in view of the deficiency of prior art, by the cooling of high-temperature steam and the recovery of cooling water, reduce the direct discharge waste of heat.

[0005] The utility model is realized by the following technical scheme, provide a kind of high-temperature steam recovery system of fixed row expansion vessel of thermal power plant, the top of fixed row expansion vessel is equipped with steam discharge pipe, at least two atomizing nozzles along vertical direction are fixed in the steam discharge pipe, the atomizing nozzle is connected with the cooling water pipe extending to the outside of steam discharge pipe respectively;It also includes drain pipe and water storage pool, the water inlet end of drain pipe is communicated with the bottom water outlet of fixed row expansion vessel, the water outlet end of drain pipe extends to the water storage pool, direct discharge valve is installed on drain pipe, bypass valve is arranged above direct discharge valve, the inlet of bypass valve is communicated with the upstream side drain pipe of direct discharge valve, the outlet of bypass valve is communicated with the downstream side drain pipe of direct discharge valve, and bypass valve is higher than the bottom water outlet of fixed row expansion vessel in height direction.

[0006] In use, cooling water is supplied to the atomizing nozzle through the cooling water pipe, and the cooling water sprayed by the atomizing nozzle forms a water film, exchanges heat with the high-temperature steam, condenses the high-temperature steam, and the condensed water flows downward into the fixed row expansion vessel, reducing the loss of discharged heat. By arranging the bypass valve, in normal operation, the bypass valve is in an open state, and the direct discharge valve is in a closed state, so that water is always present in the pipeline between the bypass valve and the fixed row expansion vessel, forming a water seal to prevent steam in the fixed row expansion vessel from being discharged from the bottom.

[0007] As optimization, the cold water pipe is provided with a cooling water pipe, the water inlet end of the cooling water pipe is communicated with the cold water pipe, and the water outlet end of the cooling water pipe extends to the water storage pool. The optimization scheme can reduce the temperature in the water storage pool by introducing the cooling water in the cold water pipe to the water storage pool through the cooling water pipe.

[0008] As optimization, the water storage pool is provided with a water mixing pump, the water outlet of the water mixing pump is communicated with the water storage pool through a circulating outlet pipe, the water inlet of the water mixing pump is communicated with the water storage pool through a circulating inlet pipe, and the communication point of the circulating inlet pipe with the water storage pool is below the liquid level in the water storage pool. The optimization scheme can improve the consistency of the water temperature in the water storage pool by circulating the water in the water storage pool through the water mixing pump.

[0009] As optimization, the water storage pool is provided with a temperature sensor, and the temperature sensor is electrically connected with the cooling valve and the water mixing pump. The optimization scheme can detect the temperature of the water in the water storage pool through the temperature sensor, so as to control the cooling valve and the water mixing pump, and avoid adding excessive cooling water into the water storage pool.

[0010] As optimization, the water storage pool is provided with a water conveying pipe provided with a water pump and a water conveying valve, the water inlet end of the water conveying pipe is communicated with the water storage pool, and the water outlet end of the water conveying pipe is communicated with the hot water inlet pipe of the indoor heating pipe. The optimization scheme can convey the hot water in the water storage pool to the indoor heating pipe through the water pump and the water conveying pipe, so as to be used for indoor heating, and reduce the waste of heat energy.

[0011] As optimization, the cold water pipe is provided with a water spraying valve, and the interval between two adjacent water spraying valves in the vertical direction is not greater than 5m. The optimization scheme can avoid that the interval between the two water spraying valves is too large and affects the concentrated cooling effect.

[0012] As optimization, the steam exhaust pipe is provided with cooling fins below the water spraying head, the cooling fins are fixedly arranged on the opposite side walls of the steam exhaust pipe, the cooling fins are sealingly connected with the pipe wall of the steam exhaust pipe, the two cooling fins are both arranged in a downward inclined manner, one end of the two cooling fins in the steam exhaust pipe is arranged in a vertical direction, and a steam passage is formed between the two cooling fins. The optimization scheme can realize the preliminary cooling of the high-temperature steam, slow down the flow of the steam, and improve the cooling effect of the water spraying head on the steam.

[0013] The utility model discloses the beneficial effects are: through setting up the water spraying head in the steam exhaust pipe, the high-temperature steam is condensed, and the condensed water flows to the fixed exhaust expander, and the loss of heat energy is reduced. Through the bypass valve, the water in the pipeline is used to form a water seal at the bottom of the fixed exhaust expander, and the steam is prevented from being discharged from the bottom. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is flow structure schematic diagram of the utility model.

[0015] As shown in the figure:

[0016] 1, fixed expansion vessel, 2, cooling fins, 3, steam exhaust pipe, 4, atomizing nozzle, 5, cold water pipe, 6, water spray valve, 7, water delivery pipe, 8, water pump, 9, bypass valve, 10, direct discharge valve, 11, water mixing pump, 12, water storage tank, 13, drain pipe, 14, cool water mixing valve, 15, cool water mixing pipe. DETAILED DESCRIPTION

[0017] In order to clearly illustrate the technical features of the present scheme, the present scheme will be described below through specific embodiments.

[0018] As Figure 1 shown in a thermal power plant fixed expansion vessel high temperature steam recovery system, the top of the fixed expansion vessel 1 is provided with a steam exhaust pipe 3, the steam exhaust pipe 3 is provided with at least two atomizing nozzles 4 distributed in the vertical direction, the atomizing nozzles 4 are respectively connected to the cold water pipe 5 extending outside the steam exhaust pipe. The cold water pipe is respectively provided with a water spray valve 6, and the distance between the two adjacent atomizing nozzles in the vertical direction is not greater than 5 meters. The atomizing nozzles of the present embodiment are arranged in two along the vertical direction, forming two atomizing water cooling in the steam exhaust pipe, improving the condensation efficiency. In actual use, the high pressure pump or compressed air device in the prior art is used to provide pressure for the cold water in the cold water pipe, so as to better realize atomization.

[0019] The two opposite side walls of the steam exhaust pipe are respectively provided with cooling fins 2 located below the atomizing nozzles 4, the cooling fins 2 are sealingly connected with the pipe wall of the steam exhaust pipe, both the cooling fins are inclined downward, and the two cooling fins are distributed in the vertical direction at one end in the steam exhaust pipe, and a steam passage is formed between the two cooling fins. The cooling fins are used for primary heat exchange cooling of high temperature steam, and the flow of steam is blocked and decelerated, so that the cold water sprayed by the atomizing nozzles can be fully heat exchanged with the steam.

[0020] The steam recovery system of the present embodiment further comprises a drain pipe 13 and a water storage tank 12, the water inlet end of the drain pipe 13 is communicated with the water outlet at the bottom of the fixed expansion vessel 1, the water outlet end of the drain pipe 13 extends to the water storage tank 12, the drain pipe 13 is provided with a direct discharge valve 10, the bypass valve 9 is arranged above the direct discharge valve 10, the inlet of the bypass valve 9 is communicated with the drain pipe on the upstream side of the direct discharge valve, the outlet of the bypass valve 9 is communicated with the drain pipe on the downstream side of the direct discharge valve, and the height of the bypass valve 9 is higher than the water outlet at the bottom of the fixed expansion vessel 1. In normal use, the direct discharge valve is closed and the bypass valve is opened, the water in the fixed expansion vessel enters the water storage tank through the bypass valve, by setting the height of the bypass valve to be higher than the water outlet at the bottom of the fixed expansion vessel, so that there is accumulated water in the pipeline between the bypass valve and the fixed expansion vessel, thereby forming a water seal to prevent the steam in the fixed expansion vessel from being discharged from the bottom.

[0021] To facilitate the reduction of water temperature in the storage tank, the steam recovery system in this embodiment also includes a cooling water pipe 15 equipped with a cooling valve 14. The inlet end of the cooling water pipe 15 is connected to the cold water pipe 5, and the outlet end of the cooling water pipe 15 extends to the storage tank 12. When the cooling valve is opened, the cold water in the cold water pipe enters the storage tank and mixes with the hot water in the storage tank, thus preventing high-temperature damage to the water pump that draws water from the storage tank.

[0022] To improve the mixing efficiency of cold and hot water in the storage tank, the steam recovery system in this embodiment also includes a water mixing pump 11. The outlet of the water mixing pump 11 is connected to the storage tank through a circulation outlet pipe, and the inlet of the water mixing pump 11 is connected to the storage tank through a circulation inlet pipe. The connection point between the circulation inlet pipe and the storage tank is located below the liquid level in the storage tank. After cold water is introduced into the storage tank, the water mixing pump mixes the water in the storage tank, causing the water temperature in the storage tank to become uniform within a short time.

[0023] In this embodiment, the cooling valve is an electromagnetic valve, and a temperature sensor is installed in the water storage tank. The temperature sensor is electrically connected to the cooling valve and the water pump. The temperature sensor is used to detect the water temperature in the water storage tank. If the water temperature in the water storage tank exceeds the set value, the cooling valve is opened to introduce cool water into the water storage tank, and the water pump is started to circulate the water in the water storage tank. When the water temperature in the water storage tank is lower than the set value, the cooling valve and the water pump are closed.

[0024] The steam recovery system in this embodiment also includes a water delivery pipe 7 equipped with a water pump 8 and a water supply valve. The inlet end of the water delivery pipe 7 is connected to a water storage tank, and the outlet end of the water delivery pipe 7 is connected to the hot water inlet pipe of the indoor heating system. When heating is required indoors, the water supply valve is opened, and the water pump 8 is used to supply hot water from the water storage tank into the indoor heating system to meet the heating needs. The water in the water storage tank can also be used as boiler raw water or other process water to improve thermal energy utilization efficiency.

[0025] In this embodiment, the boiler continuous drainage, boiler scheduled drainage, boiler emergency drainage, various boiler drains, boiler level gauge flushing drainage, turbine condensate drainage, turbine high-pressure heater emergency drainage, and deaerator emergency drainage are all ultimately discharged into the scheduled drainage expansion container. High-temperature steam flows upward along the steam pipe, and the cooling fins are used to cool and slow down the high-temperature steam. The cold water sprayed from the atomizing nozzle forms a water screen to cool the high-temperature steam a second time. The water formed after the high-temperature steam condenses flows downward back into the scheduled drainage expansion container, realizing the recovery of steam heat and preventing the high-temperature steam from being directly discharged into the atmosphere. The water formed by the steam condensation enters the water storage tank through the drain pipe for use in heating, boiler raw water, etc.

[0026] Of course, the above description is also not limited to the above examples, the technical features not described in the utility model can be realized by or using the prior art, which will not be repeated here; the above embodiments and drawings are only used to illustrate the technical scheme of the utility model and are not a limitation on the utility model, the utility model has been described in detail with reference to the preferred embodiments, and those skilled in the art should understand that the changes, modifications, additions or replacements made by those skilled in the art within the essential scope of the utility model do not deviate from the purpose of the utility model, and should also belong to the protection scope of the claims of the utility model.

Claims

1. A high-temperature steam recovery system for a thermal power plant fixed expansion vessel row, the top of the fixed expansion vessel (1) is provided with a steam exhaust pipe (3), characterized in that: At least two atomizing nozzles (4) are arranged in the steam exhaust pipe (3) in vertical direction, and the atomizing nozzles (4) are respectively connected to the cold water pipes (5) extending to outside of the steam exhaust pipe; The water storage tank (12) is further provided with a water mixing pump (11), and the outlet of the water mixing pump (11) is connected to the water storage tank through a circulating outlet pipe, and the inlet of the water mixing pump (11) is connected to the water storage tank through a circulating inlet pipe, and the connecting point of the circulating inlet pipe and the water storage tank is below the liquid level in the water storage tank.

2. A system for recovering high temperature steam from a fixed pressure expander of a thermal power plant according to claim 1, characterized in that: The water storage tank is further provided with a water mixing pump (11), and the outlet of the water mixing pump (11) is connected to the water storage tank through a circulating outlet pipe, and the inlet of the water mixing pump (11) is connected to the water storage tank through a circulating inlet pipe, and the connecting point of the circulating inlet pipe and the water storage tank is below the liquid level in the water storage tank.

3. A system for recovering high temperature steam from a fixed pressure expander of a thermal power plant according to claim 2, characterized in that: The water storage tank is further provided with a temperature sensor, and the temperature sensor is electrically connected to the water mixing valve and the water mixing pump.

4. A system for recovering high temperature steam from a fixed pressure expander of a thermal power plant according to claim 3, characterized in that: The water storage tank is further provided with a water mixing pump (11), and the outlet of the water mixing pump (11) is connected to the water storage tank through a circulating outlet pipe, and the inlet of the water mixing pump (11) is connected to the water storage tank through a circulating inlet pipe, and the connecting point of the circulating inlet pipe and the water storage tank is below the liquid level in the water storage tank.

5. A system for recovering high temperature steam from a fixed pressure expander of a thermal power plant according to claim 1, characterized in that: The water storage tank is further provided with a temperature sensor, and the temperature sensor is electrically connected to the water mixing valve and the water mixing pump.

6. A system for recovering high temperature steam from a fixed pressure expander of a thermal power plant according to claim 1, characterized in that: The water storage tank is further provided with a water mixing pump (11), and the outlet of the water mixing pump (11) is connected to the water storage tank through a circulating outlet pipe, and the inlet of the water mixing pump (11) is connected to the water storage tank through a circulating inlet pipe, and the connecting point of the circulating inlet pipe and the water storage tank is below the liquid level in the water storage tank.

7. A system for recovering high temperature steam from a fixed pressure expander of a thermal power plant according to claim 1, characterized in that: The water storage tank is further provided with a temperature sensor, and the temperature sensor is electrically connected to the water mixing valve and the water mixing pump. The water storage tank is further provided with a water mixing pump (11), and the outlet of the water mixing pump (11) is connected to the water storage tank through a circulating outlet pipe, and the inlet of the water mixing pump (11) is connected to the water storage tank through a circulating inlet pipe, and the connecting point of the circulating inlet pipe and the water storage tank is below the liquid level in the water storage tank. The water storage tank is further provided with a temperature sensor, and the temperature sensor is electrically connected to the water mixing valve and the water mixing pump. The water storage tank is further provided with a water mixing pump (11), and the outlet of the water mixing pump (11) is connected to the water storage tank through a circulating outlet pipe, and the inlet of the water mixing pump (11) is connected to the water storage tank through a circulating inlet pipe, and the connecting point of the circulating inlet pipe and the water storage tank is below the liquid level in the water storage tank. The water storage tank is further provided with a temperature sensor, and the temperature sensor is electrically connected to the water mixing valve and the water mixing pump. The water storage tank is further provided with a water mixing pump (11), and the outlet of the water mixing pump (11) is connected to the water storage tank through a circulating outlet pipe, and the inlet of the water mixing pump (11) is connected to the water storage tank through a circulating inlet pipe, and the connecting point of the circulating inlet pipe and the water storage tank is below the liquid level in the water storage tank. The water storage tank is further provided with a temperature sensor, and the temperature sensor is electrically connected to the water mixing valve and the water mixing pump.

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