Flash evaporation system

Abstract

The utility model relates to the technical field of polycrystalline silicon production, in particular to a flash evaporation system. The flash evaporation system comprises a first flash evaporation tank, a second flash evaporation tank, a first condensate pipe network, a second condensate pipe network, a first pipeline and a liquid supplementing pipeline, the first flash tank is configured to generate first steam, the second flash tank is configured to generate second steam, and the pressure of the second steam is larger than that of the first steam; the first condensate pipe network is respectively connected with the first flash tank and the second flash tank, the second condensate pipe network is connected with the second flash tank, and the condensate pressure provided by the second condensate pipe network is greater than that provided by the first condensate pipe network; the first pipeline is respectively connected with the first flash tank and the second flash tank, and the liquid supplementing pipeline is connected with the first flash tank. The first flash evaporation tank and the second flash evaporation tank achieve cascade liquid supplementing, the steam quantity produced by the first flash evaporation tank and the second flash evaporation tank is increased, meanwhile, the flash evaporation system can produce high-grade steam as much as possible, the externally supplemented steam quantity can be reduced, and the production cost of polycrystalline silicon is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of polysilicon production, and in particular to a flash evaporation system. Background Art

[0002] The reduction section is the most power-consuming section in polysilicon production. The consumed energy will be released in the form of radiant heat. High-temperature water is used to absorb the heat to produce saturated steam as a by-product for use in other devices, which can reduce the production cost of polysilicon.

[0003] Currently, polysilicon reduction units produce large amounts of heat at varying temperatures during the production of silicon rods, depending on production needs. This heat is removed via circulating hot water, and various levels of saturated steam are produced via flash tanks. The circulating hot water is forced through a pump and fed into the reduction furnace to extract heat. After decompression, it enters the flash tanks, producing steam as a byproduct. The flash tanks are replenished with steam condensate recovered through the condensate network and externally desalted water.

[0004] However, steam-using devices such as polysilicon distillation devices consume a large amount of steam and need to be supplemented by a large amount of steam input from the outside, resulting in a high cost of polysilicon production. Utility Model Content

[0005] Based on this, the present application provides a flash evaporation system to solve the problem in the related art that the steam user device needs to input a large amount of steam from the outside, resulting in higher costs for polysilicon production.

[0006] The flash evaporation system provided in the present application includes a first flash tank, a second flash tank, a first condensate pipe network, a second condensate pipe network, a first pipeline and a liquid replenishment pipeline;

[0007] The first flash tank is configured to generate a first steam, and the second flash tank is configured to generate a second steam, the second steam having a pressure greater than a pressure of the first steam;

[0008] The first condensate pipe network is connected to the first flash tank and the second flash tank respectively, the second condensate pipe network is connected to the second flash tank, and the condensate pressure provided by the second condensate pipe network is greater than the condensate pressure provided by the first condensate pipe network;

[0009] The first pipeline is connected to the first flash tank and the second flash tank respectively, and the liquid replenishing pipeline is connected to the first flash tank.

[0010] In one possible implementation, the flash system further includes a third flash tank, a third condensate pipe network, and a second pipe. The third flash tank is configured to generate third steam, and the pressure of the third steam is greater than the pressure of the second steam.

[0011] The third condensate pipe network is connected to the third flash tank, and the second pipeline is connected to the second flash tank and the third flash tank respectively.

[0012] In a possible implementation, the flash evaporation system further includes a condensate tank and a third pipeline. The condensate tank is connected to the first condensate pipeline network and the second condensate pipeline network respectively. The third pipeline connects the condensate tank and the first flash evaporation tank.

[0013] In a possible implementation, a first liquid level controller is installed on the first flash tank, a first valve is provided on the liquid replenishment pipeline, and the first liquid level controller is electrically connected to the first valve.

[0014] In a possible implementation, second valves are installed on the portion of the first condensate pipe network connected to the second flash tank and on the first pipeline, and a second liquid level controller is installed on the second flash tank. The second liquid level controller is electrically connected to the two second valves.

[0015] In a possible implementation, third valves are installed on the third condensate network and the second pipeline respectively, a third liquid level controller is installed on the third flash tank, and the third liquid level controller is electrically connected to the two third valves respectively.

[0016] In one possible implementation, the third pipeline includes a main pipe, a first branch pipe, and a second branch pipe. One end of the main pipe is connected to the condensate tank, and the other end of the main pipe is connected to the first branch pipe and the second branch pipe respectively. The end of the first branch pipe away from the main pipe is connected to the first flash tank, and the second branch pipe is configured to discharge excess condensate.

[0017] In a possible implementation, a fourth liquid level controller is installed on the condensate tank, a fourth valve is installed on the main pipe, and the fourth valve is electrically connected to the fourth liquid level controller.

[0018] In a possible implementation, a pump body is installed on each of the first pipeline, the second pipeline, and the third pipeline.

[0019] In a possible implementation, a booster pump is installed on the first condensate pipe network.

[0020] The flash evaporation system provided in the present application has a first flash tank and a second flash tank that can respectively generate a first steam and a second steam, wherein the pressure of the first steam is lower than that of the second steam. A first pipeline is connected between the first flash tank and the second flash tank, and the first flash tank is also connected to the first condensate pipeline network and the liquid replenishment pipeline, respectively. The second flash tank is also connected to the first condensate pipeline network and the second condensate pipeline network, respectively. When the flash evaporation system is in operation, liquid can be replenished to the second flash tank through the second condensate pipeline network first. If the liquid level in the second flash tank is insufficient, liquid can also be replenished to the second flash tank through the first condensate pipeline network and the first flash tank. Liquid can also be replenished to the first flash tank through the first condensate pipeline network first. If the liquid level in the first flash tank is insufficient, liquid can also be replenished to the first flash tank through the liquid replenishment pipe. In this way, the first flash tank and the second flash tank achieve cascade liquid replenishment, and the temperature difference between the condensate replenished in the flash tank and the condensate inside the flash tank is small, which reduces the energy loss in the mixing process, improves the energy utilization rate, and increases the steam output of the first flash tank and the second flash tank. At the same time, the flash system produces as much high-grade steam as possible, which is beneficial to reduce the amount of external steam replenishment and reduce the production cost of polysilicon. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1 A schematic structural diagram of a flash evaporation system provided in an embodiment of the present application;

[0023] Figure 2 A schematic structural diagram of another flash evaporation system provided in an embodiment of the present application.

[0024] Description of reference numerals:

[0025] 100 - first flash tank; 110 - first liquid level controller; 120 - first steam pipeline;

[0026] 200 - second flash tank; 210 - second liquid level controller; 220 - second steam pipeline;

[0027] 300-third flash tank; 310-third liquid level controller; 320-third steam pipeline;

[0028] 400- condensate tank; 410- fourth liquid level controller;

[0029] 510 - first condensate pipe network; 520 - second condensate pipe network; 530 - third condensate pipe network;

[0030] 610 - first pipeline; 620 - second pipeline; 630 - third pipeline; 631 - main pipeline; 632 - first branch pipeline; 633 - second branch pipeline;

[0031] 700-Fluid infusion line;

[0032] 810 - first valve; 820 - second valve; 830 - third valve; 840 - fourth valve;

[0033] 900-Pump body. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be understood as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of the present application are described in detail below in conjunction with the drawings.

[0035] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to a fixed connection, an indirect connection via an intermediate medium, internal communication between two components, or an interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0036] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are orientations or positional relationships based on the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0037] The terms "first", "second" and "third" (if any) in the description and claims of this application and the above drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0038] In addition, the terms "comprises" and "having" and any variations thereof are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or display that includes a series of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, product or display.

[0039] In the prior art, when a polysilicon reduction device produces silicon rods, it can produce a large amount of heat at different temperature levels according to production needs. This heat is taken away by circulating hot water and produced as a by-product of various levels of saturated steam through a flash tank. The circulating hot water is forced to circulate through a pump and sent into the reduction furnace to extract heat. After being decompressed, it enters the flash tank to produce steam as a by-product. The flash tank is replenished with steam condensate recovered through the condensate pipe network and external desalted water. However, the temperature of the desalted water is relatively low, and the temperature difference between it and the condensate inside the flash tank is relatively large. A lot of energy is lost during the mixing process of the desalted water and the condensate inside the flash tank, resulting in less steam produced by the flash tank. Steam user devices such as polysilicon distillation devices also need to input more steam from the outside, making the cost of polysilicon production relatively high.

[0040] After repeated deliberation and verification, the inventors discovered that if the flash tanks of different levels in the flash system are replenished in a tiered manner, that is, the condensate in the corresponding condensate network is preferentially used for replenishment, and if the flash tank is low on liquid, the condensate in the adjacent lower-level flash tank or the condensate in the first-level condensate network is used for replenishment. This can reduce the significant energy loss when the condensate added to the flash tank mixes with the condensate already in the flash tank, improve energy utilization, increase the steam output of the flash tank, and simultaneously enable the flash system to produce as much high-grade steam as possible, reduce the amount of external steam replenishment, and lower the production cost of polysilicon.

[0041] In light of this, the inventors have designed a flash evaporation system in which a first flash tank and a second flash tank can each produce two grades of steam, and the steam pressure generated by the second flash tank is greater than that generated by the first flash tank. The condensate pressure provided by the second condensate pipe network is greater than the condensate pressure of the first condensate pipe network. The first flash tank and the second flash tank are connected by a first pipeline. The first condensate pipe network connects the first flash tank and the second flash tank, and the second condensate pipe network connects the second flash tank. The first flash tank is also connected to a fluid replenishment pipeline. The second flash tank can be replenished with condensate from the second condensate pipe network first, and if the fluid supply is insufficient, it can also be replenished with condensate from the first condensate pipe network and the first flash tank. The first flash tank can be replenished with condensate from the first condensate pipe network first, and if the fluid supply is insufficient, it can also be replenished with desalted water through the fluid replenishment pipeline. In this way, different flash tanks can be replenished in stages, and the condensate energy in the first condensate network and the second condensate network can be fully utilized, thereby increasing the steam output of the flash tanks and allowing the flash system to produce as much high-grade steam as possible.

[0042] The technical solution of the flash evaporation system provided in the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0043] Reference Figure 1 and Figure 2 As shown, the flash evaporation system provided in an embodiment of the present application includes a first flash tank 100, a second flash tank 200, a first condensate pipe network 510, a second condensate pipe network 520, a first pipeline 610, and a fluid replenishment pipe network 700. The first flash tank 100 is configured to generate a first steam, and the second flash tank 200 is configured to generate a second steam, the pressure of the second steam being greater than the pressure of the first steam. The first condensate pipe network 510 is connected to the first flash tank 100 and the second flash tank 200 respectively, and the second condensate pipe network 520 is connected to the second flash tank 200. The condensate pressure provided by the second condensate pipe network 520 is greater than the condensate pressure provided by the first condensate pipe network 510. The first pipeline 610 is connected to the first flash tank 100 and the second flash tank 200 respectively, and the fluid replenishment pipe network 700 is connected to the first flash tank 100.

[0044] For example, the first flash tank 100 can be a 0.2 MPaG flash tank, which can generate 0.2 MPaG steam. The generated steam can be converted into 0.2 MPaG condensate after being used by other polysilicon production equipment. The steam is then pressurized to 0.7 MPaG-0.9 MPaG by the user's device or by the booster pump provided by the first condensate pipe network 510, and then transported through the first condensate pipe network 510. The second flash tank 200 can be a 0.3 MPaG-0.6 MPaG flash tank, which can generate 0.3 MPaG-0.6 MPaG steam. The generated steam can be converted into 0.3 MPaG-0.6 MPaG condensate after being used by other polysilicon production equipment. The steam is then pressurized to 0.7 MPaG-0.9 MPaG by the user's device, and then transported through the second condensate pipe network 520. It can be understood that the first steam is 0.2MPaG steam, the second steam is 0.3MPaG-0.6MPaG steam, the temperature of the condensate in the second condensate pipe network 520 is greater than the temperature of the condensate in the first condensate pipe network 510, and the pressure of the condensate in the second condensate pipe network 520 is not lower than the pressure of the condensate in the first condensate pipe network 510.

[0045] Illustratively, the steam generated by the first flash tank 100 can be delivered to other polysilicon production equipment via a first steam pipeline 120, and the steam generated by the second flash tank 200 can be delivered to other polysilicon production equipment via a second steam pipeline 220. The steam generated by the first flash tank 100 and the steam generated by the second flash tank 200 can be delivered to different polysilicon production equipment respectively, or can be delivered to the same polysilicon production equipment, which is not limited here.

[0046] It is worth mentioning that when the condensate provided by the second condensate pipe network 520 is insufficient to replenish the second flash tank 200, the second flash tank 200 is preferentially replenished with the condensate provided by the first condensate pipe network 510 and then with the condensate in the first flash tank 100, thereby ensuring the liquid level in the first flash tank 100 as much as possible. Optionally, the replenishment line 700 can provide desalted water to the first flash tank 100 to achieve replenishment of the first flash tank 100.

[0047] The flash evaporation system provided in this embodiment has a first flash tank 100 and a second flash tank 200 that can generate first steam and second steam, respectively, with the pressure of the first steam being lower than that of the second steam. A first pipeline 610 is connected between the first flash tank 100 and the second flash tank 200. The first flash tank 100 is also connected to the first condensate pipe network 510 and the liquid replenishment pipe 700, respectively. The second flash tank 200 is also connected to the first condensate pipe network 510 and the second condensate pipe network 520, respectively. During operation, the flash evaporation system can first replenish liquid into the second flash tank 200 through the second condensate pipe network 520. If the liquid level in the second flash tank 200 is insufficient, liquid can be replenished into the second flash tank 200 through the first condensate pipe network 510 and the first flash tank 100. Liquid can also first be replenished into the first flash tank 100 through the first condensate pipe network 510. If the liquid level in the first flash tank 100 is insufficient, liquid can be replenished into the first flash tank 100 through the liquid replenishment pipe. In this way, the first flash tank 100 and the second flash tank 200 achieve cascaded liquid replenishment, with the flash tank replenishment primarily derived from condensate at the corresponding grade, reducing energy waste during polysilicon production and improving energy utilization. When condensate at a corresponding grade is insufficient, water or steam condensate from the adjacent flash tank at the next lower level is used to replenish the condensate. The temperature difference between adjacent steam condensates is small, reducing energy loss during the mixing process and increasing the steam output of the first flash tank 100 and the second flash tank 200. This also allows the flash evaporation system to produce as much high-grade steam as possible, thereby reducing the amount of external steam replenishment and lowering the production cost of polysilicon.

[0048] In one embodiment, Figure 2 As shown, the flash system further includes a third flash tank 300, a third condensate piping network 530, and a second pipeline 620. The third flash tank 300 is configured to generate a third steam having a pressure greater than that of the second steam. The third condensate piping network 530 is connected to the third flash tank 300, and the second pipeline 620 is connected to the second flash tank 200 and the third flash tank 300, respectively.

[0049] For example, the third flash tank 300 can be a 1.0 MPaG flash tank that can generate 1.0 MPaG steam. This steam, after being used by other polysilicon production equipment, can be converted into 1.0 MPaG condensate. This steam is then pressurized to 1.3 MPaG-1.6 MPaG within the user equipment and transported through the third condensate pipe network 530. The third steam is 1.0 MPaG steam, which can be transported to other polysilicon production equipment via the third steam pipeline 320. The temperature and pressure of the condensate in the third condensate pipe network 530 are greater than those in the second condensate pipe network 520.

[0050] When the flash system is running, the third flash tank 300 can be replenished with the condensate provided by the third condensate pipe network 530 first. When the condensate provided by the third condensate pipe network 530 is insufficient for replenishment, the third flash tank 300 can also be replenished with the condensate inside the second flash tank 200.

[0051] With this structure, the flash evaporation system can provide more grades of steam. At the same time, the higher-pressure condensate in the third condensate pipe network 530 only enters the third flash tank 300, so that the energy of the condensate in the third condensate pipe network 530 is fully utilized. The flash evaporation system produces as much high-grade steam as possible. The steam output of the first flash tank 100, the second flash tank 200 and the third flash tank 300 can all be guaranteed, further reducing the amount of external steam supply and lowering the cost of polysilicon production.

[0052] In a specific embodiment, Figure 1 and Figure 2 As shown, the flash evaporation system further includes a condensate tank 400 and a third pipeline 630 . The condensate tank 400 is connected to the first condensate pipe network 510 and the second condensate pipe network 520 respectively. The third pipeline 630 connects the condensate tank 400 and the first flash evaporation tank 100 .

[0053] Among them, the condensate tank 400 can assist in collecting condensate. The condensate produced as a by-product of the self-used steam in the reduction device and the hydrophobic condensate or low-pressure condensate in the entire plant can be recovered through the condensate tank 400. The fluctuating condensate in the flash evaporation system and the reduction device can be buffered by the condensate tank 400, so that the flash evaporation system and the reduction device can operate stably.

[0054] It is worth mentioning that when the condensate in the first condensate pipe network 510 is insufficient to replenish the first flash tank 100, the condensate in the condensate tank 400 can be preferentially used to replenish the first flash tank 100 through the third pipeline 630, so as to reduce the amount of external desalted water and further reduce the production cost of polysilicon.

[0055] In a more specific embodiment, Figure 1 and Figure 2As shown, a first liquid level controller 110 is installed on the first flash tank 100, a first valve 810 is provided on the liquid replenishing pipeline 700, and the first liquid level controller 110 is electrically connected to the first valve 810.

[0056] Illustratively, the first flash tank 100 is preferentially replenished through the condensate in the first condensate pipe network 510, and the condensate in the condensate tank 400 can continuously flow to the first flash tank 100 through the third pipe 630 to continuously replenish the first flash tank 100. The first liquid level controller 110 can control the opening of the first valve 810 according to the liquid level in the first flash tank 100 to achieve automatic replenishment of desalted water, while ensuring that the condensate in the first condensate pipe network 510 and the condensate tank 400 is fully utilized, thereby improving the energy utilization efficiency of the first flash tank 100 and increasing the first steam production of the first flash tank 100.

[0057] This embodiment does not limit the specific structures of the first valve 810 and the first liquid level controller 110 , and those skilled in the art can configure them according to actual needs.

[0058] like Figure 1 and Figure 2 As shown, the second valves 820 are installed on the portion where the first condensate pipe network 510 is connected to the second flash tank 200 and on the first pipeline 610 . The second liquid level controller 210 is installed on the second flash tank 200 , and the second liquid level controller 210 is electrically connected to the two second valves 820 .

[0059] The second valve 820 on the first condensate network 510 can control the amount of condensate input from the first condensate network 510 to the second flash tank 200 , and the second valve 820 on the first pipeline 610 can control the amount of condensate input from the first flash tank 100 to the second flash tank 200 .

[0060] As can be understood, all the condensate in the second condensate piping network 520 flows to the second flash tank 200. The second liquid level controller 210 can detect the liquid level in the second flash tank 200. When the liquid level in the second flash tank 200 is low, the second liquid level controller 210 can first control the second valve 820 on the first condensate piping network 510 to open. At this time, the condensate in the first condensate pipe can flow to the second flash tank 200 to replenish the second flash tank 200. If the second liquid level controller 210 still detects that the liquid level in the second flash tank 200 is low, the second liquid level controller 210 controls the second valve 820 on the first pipeline 610 to open. At this time, the condensate in the first flash tank 100 can flow to the second flash tank 200 to replenish the second flash tank 200.

[0061] This structure can control the flow of different condensates to the second flash tank 200 according to the liquid level in the second flash tank 200, thereby ensuring the stability of the operation of the flash system and the reduction device, and at the same time ensuring that the condensate in the second condensate pipe network 520 is fully utilized to fully recover and utilize the large amount of heat generated by the reduction device.

[0062] Figure 2 It is shown that the third condensate pipe network 530 and the second pipe 620 are respectively installed with third valves 830 , and the third flash tank 300 is installed with a third liquid level controller 310 . The third liquid level controller 310 is electrically connected to the two third valves 830 .

[0063] Among them, the third liquid level controller 310 can detect the liquid level in the third flash tank 300, the third valve 830 on the third condensate pipeline 530 can control the third condensate pipeline 530 to input condensate into the third flash tank 300, and the third valve 830 on the second pipeline 620 can control the second flash tank 200 to input condensate into the third flash tank 300.

[0064] When the third liquid level controller 310 detects that the liquid level in the third flash tank 300 is low, the third liquid level controller 310 can first control the third valve 830 on the third condensate pipe network 530 to open, so that the condensate in the third condensate pipe network 530 flows to the third flash tank 300 to replenish the third flash tank 300; when the third liquid level controller 310 still detects that the liquid level in the third flash tank 300 is low, the third liquid level controller 310 again controls the third valve 830 on the second pipeline 620 to open, so that the condensate in the second flash tank 200 flows to the third flash tank 300 to replenish the third flash tank 300.

[0065] Through the above arrangement, different condensates can be controlled to flow to the third flash tank 300 according to the liquid level in the third flash tank 300, thereby ensuring the stability of the operation of the flash system and the reduction device. At the same time, the condensate in the third condensate pipe network 530 is fully utilized to fully recover the large amount of heat generated by the reduction device, while allowing the flash system to produce high-quality steam as much as possible.

[0066] like Figure 1 and Figure 2 As shown, the third pipeline 630 includes a main pipe 631, a first branch pipe 632, and a second branch pipe 633. One end of the main pipe 631 is connected to the condensate tank 400, and the other end of the main pipe 631 is connected to the first branch pipe 632 and the second branch pipe 633 respectively. The end of the first branch pipe 632 away from the main pipe 631 is connected to the first flash tank 100, and the second branch pipe 633 is configured to discharge excess condensate.

[0067] For example, the end of the main pipe 631 away from the condensate tank 400 can be connected to the first branch pipe 632 and the second branch pipe 633 via a tee joint. The condensate in the condensate tank 400 can flow to the first flash tank 100 via the main pipe 631 and the first branch pipe 632, and the condensate in the condensate tank 400 can also be discharged from the flash system via the main pipe 631 and the second branch pipe 633.

[0068] By controlling the flow direction of the condensate in the condensate tank 400 in the third pipeline 630, the condensate in the condensate tank 400 can be controlled to flow to the first flash tank 100 or be discharged from the flash evaporation system, thereby ensuring that the liquid levels in the first flash tank 100 and the condensate tank 400 are stable, ensuring that the first flash tank 100 can reliably generate steam, and at the same time, the flash evaporation system and the reduction device have sufficient condensate to cool the reduction device.

[0069] Figure 1 and Figure 2 It is shown that a fourth liquid level controller 410 is installed on the condensate tank 400 , a fourth valve 840 is installed on the main pipe 631 , and the fourth valve 840 is electrically connected to the fourth liquid level controller 410 .

[0070] The fourth liquid level controller 410 can detect the liquid level in the condensate tank 400, and the fourth valve 840 can control the flow rate of condensate in the third pipeline 630. When the liquid level in the condensate tank 400 is low, the fourth liquid level controller 410 can reduce the opening of the fourth valve 840, thereby reducing the condensate flowing out of the condensate tank 400. When the liquid level in the condensate tank 400 is high, the fourth liquid level controller 410 can increase the opening of the fourth valve 840, thereby increasing the condensate flowing out of the condensate tank 400. If the amount of condensate flowing out of the condensate tank 400 is large, the excess condensate can be discharged from the flash evaporation system through the second branch pipe 633.

[0071] This structure can control the liquid level in the condensate tank 400 by controlling the opening of the fourth valve 840, ensuring that there is sufficient condensate in the flash evaporation system and the reduction device, while avoiding excessive condensate in the condensate tank 400 affecting the stability of the operation of the flash evaporation system and the reduction device.

[0072] In a specific embodiment, Figure 1 and Figure 2 As shown, a pump body 900 is installed on the first pipeline 610 , the second pipeline 620 and the third pipeline 630 respectively.

[0073] Among them, the pump body 900 can increase the condensate pressure. The pump body 900 on the first pipeline 610 can drive the condensate in the first flash tank 100 to flow to the second flash tank 200, the pump body 900 on the second pipeline 620 can drive the condensate in the second flash tank 200 to flow to the third flash tank 300, and the pump body 900 on the third pipeline 630 can drive the condensate in the condensate tank 400 to flow to the first flash tank 100.

[0074] The pump body 900 can drive the condensate with lower pressure to flow to the flash tank with higher pressure, so as to realize the flow of low-pressure condensate to high-pressure, reduce the energy loss of condensate when mixing in the flash tank, and improve the energy utilization rate of the flash system.

[0075] Optionally, a booster pump is installed on the first condensate pipe network 510 .

[0076] Among them, the booster pump can increase the pressure of the condensate in the first condensate pipe network 510. When the first condensate pipe network 510 replenishes the second flash tank 200, the booster pump can increase the condensate pressure in the first condensate pipe network 510 to 0.7MPaG-0.9MpaG, ensuring that the condensate in the first condensate pipe network 510 can reliably flow to the second flash tank 200 to replenish the second flash tank 200.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A flash evaporation system, characterized in that: It comprises a first flash tank (100), a second flash tank (200), a first condensate pipe network (510), a second condensate pipe network (520), a first pipeline (610) and a liquid replenishing pipeline (700); The first flash tank (100) is configured to generate a first steam, and the second flash tank (200) is configured to generate a second steam, wherein the pressure of the second steam is greater than the pressure of the first steam; The first condensate pipe network (510) is connected to the first flash tank (100) and the second flash tank (200), respectively; the second condensate pipe network (520) is connected to the second flash tank (200); and the condensate pressure provided by the second condensate pipe network (520) is greater than the condensate pressure provided by the first condensate pipe network (510); The first pipeline (610) is connected to the first flash tank (100) and the second flash tank (200), respectively, and the liquid infusion pipeline (700) is connected to the first flash tank (100); The flash system further comprises a third flash tank (300), a third condensate pipe network (530) and a second pipeline (620), wherein the third flash tank (300) is configured to generate a third steam, wherein the pressure of the third steam is greater than the pressure of the second steam; The third condensate pipe network (530) is connected to the third flash tank (300), and the second pipeline (620) is respectively connected to the second flash tank (200) and the third flash tank (300); The flash evaporation system further includes a condensate tank (400) and a third pipeline (630), wherein the condensate tank (400) is connected to the first condensate pipe network (510) and the second condensate pipe network (520) respectively, and the third pipeline (630) connects the condensate tank (400) and the first flash evaporation tank (100).

2. The flash evaporation system according to claim 1, characterized in that A first liquid level controller (110) is installed on the first flash tank (100), a first valve (810) is provided on the liquid replenishing pipeline (700), and the first liquid level controller (110) is electrically connected to the first valve (810).

3. The flash evaporation system according to claim 1, characterized in that A second valve (820) is installed on the portion where the first condensate pipe network (510) is connected to the second flash tank (200) and on the first pipeline (610), and a second liquid level controller (210) is installed on the second flash tank (200). The second liquid level controller (210) is electrically connected to the two second valves (820), respectively.

4. The flash evaporation system according to claim 1, characterized in that A third valve (830) is installed on the third condensate pipe network (530) and the second pipe (620), respectively. A third liquid level controller (310) is installed on the third flash tank (300), and the third liquid level controller (310) is electrically connected to the two third valves (830), respectively.

5. The flash evaporation system according to claim 1, characterized in that: The third pipeline (630) includes a main pipe (631), a first branch pipe (632), and a second branch pipe (633). One end of the main pipe (631) is connected to the condensate tank (400), and the other end of the main pipe (631) is connected to the first branch pipe (632) and the second branch pipe (633), respectively. An end of the first branch pipe (632) away from the main pipe (631) is connected to the first flash tank (100), and the second branch pipe (633) is configured to discharge excess condensate.

6. The flash evaporation system according to claim 5, characterized in that A fourth liquid level controller (410) is installed on the condensate tank (400), a fourth valve (840) is installed on the main pipe (631), and the fourth valve (840) is electrically connected to the fourth liquid level controller (410).

7. The flash evaporation system according to claim 1, characterized in that A pump body (900) is respectively installed on the first pipeline (610), the second pipeline (620) and the third pipeline (630).

8. The flash evaporation system according to claim 1, characterized in that A booster pump is installed on the first condensate pipe network (510).

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