Energy-saving type steam circulation system

Abstract

The utility model relates to the technical field of circulating systems, in particular to an energy-saving type steam circulating system. Aiming at the problems that the condensate water of the drying cylinder cannot be normally discharged, the load of the drying cylinder is large, the normal operation is influenced, the drying cylinder can normally operate after the pressure difference of an inlet and an outlet of a drying cylinder group is increased, but the steam is discharged along with the condensate water of the drying cylinder, and the consumption is greatly increased, the following technical scheme is provided: the device comprises a first steam pipeline and a second steam pipeline, the steam pressure in the first steam pipeline is greater than that in the second steam pipeline; and the multi-stage circulation structure comprises a first drying assembly, a second drying assembly and a third drying assembly. Steam is fully utilized, the usage amount of the steam is greatly reduced, the production cost is reduced, meanwhile, the paper machine drying cylinder operates stably, drainage is smooth, and the paper machine operates stably.

Description

Technical Field

[0001] The utility model relates to the technical field of circulation systems, in particular to an energy-saving steam circulation system. Background Art

[0002] The papermaking industry is a high-energy-consuming industry, with energy costs accounting for about 20% of the total cost. With the rise in energy prices, costs are gradually rising. With the regulation of national environmental protection policies, the use of natural gas and biomass energy to gradually replace coal energy, energy consumption remains high, and research on energy-saving technologies is imminent. The traditional steam drying system for papermaking dryers is a three-stage steam-passing system, that is, the new steam first enters the high-temperature section drying cylinder, and the steam condensate generated from the high-temperature section drying cylinder is flashed twice to generate secondary steam, which is used as the steam inlet for the medium-temperature section and the low-temperature section drying cylinder, and gradually decreases to the front to form a heating gradient. This drying method has a good energy-saving effect when the machine speed is stable and the paper type and quantity are relatively stable. However, with the changes in the market environment and the continued fierce competition, the frequent switching of the machine speed, paper type and quantity of each machine has obvious disadvantages. The drainage pressure difference of the drying cylinder is limited. Especially when producing low-weight paper, the dryer has strong drying capacity and low steam pressure. The medium and low temperature sections are prone to cause the condensed water of the drying cylinder to be unable to be discharged normally, and the dryer load is large, which affects normal operation. After increasing the inlet and outlet pressure difference of the drying cylinder group, the drying cylinder can operate normally, but the steam is discharged along with the condensed water of the drying cylinder, and the consumption increases significantly. In view of this, the utility model proposes an energy-saving steam circulation system. Utility Model Content

[0003] The purpose of the utility model is to propose an energy-saving steam circulation system to address the problem in the background technology that the condensed water of the drying cylinder cannot be discharged normally, the dryer load is heavy, and the normal operation is affected. After the inlet and outlet pressure difference of the drying cylinder group is increased, the drying cylinder can operate normally, but the steam is discharged along with the condensed water of the drying cylinder, and the consumption is greatly increased.

[0004] The technical solution of the utility model: an energy-saving steam circulation system, comprising:

[0005] a first steam line and a second steam line, wherein the steam pressure in the first steam line is greater than the steam pressure in the second steam line;

[0006] Multi-level loop structure,

[0007] The multi-stage circulation structure comprises a first drying component, a second drying component and a third drying component, wherein the first drying component, the second drying component and the third drying component are all connected to the first steam pipeline and the second steam pipeline through pipelines;

[0008] It also includes a total condensate tank and a total condensate water pump. The third drying component is connected to the total condensate tank via a pipeline, and the total condensate tank and the total condensate water pump are also connected via a pipeline.

[0009] Optionally, the first drying component includes a first drying cylinder group, a first flash tank, a first condensate pump, and a first heat pump. The first drying cylinder group is connected to the second steam pipeline via a pipeline, the first drying cylinder group and the first condensate pump are both connected to the first flash tank via a pipeline, and the first steam pipeline, the first drying cylinder group, and the first flash tank are all connected to the first heat pump via a pipeline.

[0010] Optionally, the second drying component includes a second drying cylinder group, a second flash tank, a second condensate pump, and a second heat pump. The second drying cylinder group is connected to the second steam pipeline via a pipe, the second drying cylinder group and the second condensate pump are both connected to the second flash tank via a pipe, and the first steam pipeline, the second drying cylinder group, and the second flash tank are all connected to the second heat pump via a pipe.

[0011] Optionally, the third drying component includes a third drying cylinder group, a third flash tank, a third condensate pump, and a third heat pump. The third drying cylinder group is connected to the second steam pipeline via a pipeline, the third drying cylinder group and the third condensate pump are both connected to the third flash tank via a pipeline, and the first steam pipeline, the third drying cylinder group, and the third flash tank are all connected to the third heat pump via a pipeline.

[0012] Optionally, the first drying component further includes a first connecting pipe connected to the pipeline between the first drying cylinder group and the first heat pump and the second steam pipeline and the pipeline between the second drying cylinder group.

[0013] Optionally, the second drying component further includes a second connecting pipe connected to the pipeline between the second drying cylinder group and the second heat pump and the second steam pipeline and the pipeline between the third drying cylinder group.

[0014] Optionally, the third heat pump and the second heat pump have the same structure as the first heat pump.

[0015] Optionally, the first heat pump includes a mixing box, to which a tail steam inlet pipe and a steam inlet pipe, which are perpendicularly arranged, are connected, and a diameter of one end of the steam inlet pipe close to the mixing box gradually decreases.

[0016] Optionally, a speed-up section is installed at the bottom of the mixing box, the bottom of the speed-up section is connected to a connecting section, the bottom of the connecting section is connected to a diffuser section, the bottom of the diffuser section is installed with a discharge pipe, and the cross-sectional area of ​​the diffuser section decreases from top to bottom.

[0017] Compared with the prior art, the utility model has the following beneficial technical effects:

[0018] 1. The utility model uses the method of independently controlling the first drying component, the second drying component and the third drying component. The first heat pump in the first drying component is designed so that the steam condensed water generated in this section is discharged to the first flash tank. The tail steam generated by the first flash tank is mixed with the high-pressure fresh steam by the first heat pump, and the pressure is increased to the normal value of the steam pressure of this section, which is used as the steam inlet of the first drying cylinder group in this section. The condensed water generated by the first flash tank is initially discharged to the second drying cylinder group of the previous section according to the pressure conditions.

[0019] 2. The tail steam generated by the total condensing tank of the utility model is recovered through the heat exchanger for heat energy recovery. After the clean water is added, it is used as warm water for wet-end spraying water. The condensed water of the total condensing tank returns to the thermal power department for reheating to generate fresh steam. Finally, the steam pressure of each section is controlled separately, the drying cylinder is drained smoothly, the paper machine runs stably, the steam heat energy is fully recycled, and the steam consumption is saved;

[0020] In summary, the utility model makes full use of steam, the usage of steam is greatly reduced, and the production cost is reduced. At the same time, the drying cylinder of the paper machine runs stably, the drainage is unobstructed, and the paper machine runs stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of an energy-saving steam cycle system;

[0022] Figure 2 is a schematic diagram of the structure of a first heat pump;

[0023] Figure 3 yes Figure 2 Schematic diagram of the cross-sectional structure.

[0024] Reference numerals:

[0025] 1. The first steam pipeline; 2. The second steam pipeline;

[0026] 3. First drying assembly; 31. First drying cylinder group; 32. First flash tank; 33. First condensate pump; 34. First heat pump; 35. First connecting pipe;

[0027] 4. second drying assembly; 41. second drying cylinder group; 42. second flash tank; 43. second condensate pump; 44. second heat pump; 45. second connecting pipe;

[0028] 5. third drying assembly; 51. third drying cylinder group; 52. third flash tank; 53. third condensate pump; 54. third heat pump;

[0029] 6. Main condensate tank; 7. Main condensate water pump;

[0030] 341. Mixing box; 342. Tail steam inlet pipe; 343. Steam inlet pipe; 344. Speed-up section; 345. Connecting section; 346. Diffuser section; 347. Exhaust pipe. DETAILED DESCRIPTION

[0031] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all of the embodiments.

[0032] The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0033] Based on the embodiments of the present utility model, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present utility model.

[0034] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention 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 cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] Example

[0037] like Figure 1 As shown, the utility model proposes an energy-saving steam circulation system, which includes a first steam pipeline 1 and a second steam pipeline 2 , and the steam pressure in the first steam pipeline 1 is greater than the steam pressure in the second steam pipeline 2 .

[0038] Furthermore, the circulation system includes a multi-stage circulation structure, which includes a first drying component 3, a second drying component 4 and a third drying component 5. The first drying component 3, the second drying component 4 and the third drying component 5 are all connected to the first steam pipeline 1 and the second steam pipeline 2 through pipelines. The first drying component 3 includes a first drying cylinder group 31, a first flash tank 32, a first condensate pump 33 and a first heat pump 34. The first drying cylinder group 31 is connected to the second steam pipeline 2 through a pipeline. The first drying cylinder group 31 is used to dry wet paper and remove moisture therein by drying to make the paper firm and stable. The first drying cylinder group 31 and the first condensate pump 33 are both connected to the first flash tank 32 through pipelines. The first flash tank 32 is used to convert the steam introduced therein into condensate and tail steam. The first steam pipeline 1, the first drying cylinder group 31, and the first flash tank 32 are all connected to the first heat pump 34 by pipelines. The first heat pump 34 is used to fully mix the tail steam of the first drying cylinder group 31 with the high-pressure steam in the first steam pipeline 1 through the action of the first heat pump 34 and pressurize it as the inlet steam of the first drying cylinder group 31. The second drying assembly 4 includes a second drying cylinder group 41, a second flash tank 42, a second condensate pump 43, and a second heat pump 44. The second drying cylinder group 41 is connected to the second steam pipeline 2 through a pipeline. The second drying cylinder group 41 is used to dry wet paper, and the moisture therein is removed by drying to make the paper firm and stable. The second drying cylinder group 41 and the second condensate pump 43 are both connected to the second flash tank 42 through pipelines. The second flash tank 42 is used to convert the steam passed into condensate and tail steam. The first steam pipeline 1, the second drying cylinder group 41, and the second flash tank 42 are all connected to the second heat pump 44 by pipelines. The second heat pump 44 is used to mix the continuous tail steam of the second drying cylinder group 41 with the high-pressure steam in the first steam pipeline 1 through the action of the second heat pump 44, and then use it as the inlet steam of the second drying cylinder group 41. The third drying assembly 5 includes a third drying cylinder group 51, a third flash tank 52, a third condensate pump 53, and a third heat pump 54. The third drying cylinder group 51 is connected to the second steam pipeline 2 through a pipeline. The third drying cylinder group 51 is used to dry wet paper, and the moisture therein is removed by drying to make the paper firm and stable. The third drying cylinder group 51 and the third condensate pump 53 are both connected to the third flash tank 52 through pipelines. The third flash tank 52 is used to convert the steam passing therein into condensed water and tail steam. The first steam pipeline 1, the third drying cylinder group 51, the third flash tank 52 are all connected to the third heat pump 54 via pipelines. The third heat pump 54 is used to transfer the continuous tail steam of the third drying cylinder group 51 to the third heat pump 54, and fully mix and pressurize it with the high-pressure steam in the first steam pipeline 1 to be used as the inlet steam of the third drying cylinder group 51.

[0039] Furthermore, the first drying component 3 in the above circulation system also includes a first connecting pipe 35 connected to the pipeline between the first drying cylinder group 31 and the first heat pump 34 and the second steam pipeline 2 and the pipeline between the second drying cylinder group 41. The first connecting pipe 35 is used to return the generated steam and non-condensable steam to the front second drying cylinder group 41 for steam intake through the first connecting pipe 35. The second drying component 4 also includes a second connecting pipe 45 connected to the pipeline between the second drying cylinder group 41 and the second heat pump 44 and the second steam pipeline 2 and the pipeline between the third drying cylinder group 51. The second connecting pipe 45 is used to return the generated steam and non-condensable steam to the front third drying cylinder group 51 for steam intake through the second connecting pipe 45. It also includes a total condensate tank 6 and a total condensate water pump 7. The third drying component 5 is connected to the total condensate tank 6 through a pipeline. The total condensate tank 6 and the total condensate water pump 7 are also connected with a pipeline. The third condensate water pump 53 is connected to the total condensate tank 6 through a pipeline. The tail steam generated by the total condensate tank 6 is recovered through the heat exchanger for heat energy recovery. After the clean water is added, it is used as warm water for wet-end spraying water in the papermaking process. The total condensate pump 7 is used to extract the condensate from the total condensate tank 6 and return the condensate to the thermal power department for reheating to generate fresh steam, saving resources.

[0040] Finally, see Figure 2 and Figure 3 In the above circulation system, the third heat pump 54 and the second heat pump 44 have the same structure as the first heat pump 34. The first heat pump 34 includes a mixing box 341, which facilitates the mixing of tail steam with the high-pressure steam in the first steam pipeline 1. The mixing box 341 is connected with a tail steam access pipe 342 and a steam access pipe 343 which are arranged perpendicular to each other. The tail steam access pipe 342 is connected to the tail steam, and the steam access pipe 343 is connected to the high-pressure steam. The diameter of the end of the steam access pipe 343 close to the mixing box 341 gradually decreases, which is used to speed up the flow rate due to the decrease in diameter when the high-pressure steam is passed, so that the pressure difference sucks the tail steam and mixes with it. The bottom of the mixing box 341 is also equipped with a speed-up section 344, which is a conical setting, which is convenient for the mixed steam to increase its flow rate when passing through, so that the mixed steam reaches the speed of sound when it is discharged. The bottom of the speed-up section 344 is connected to a connecting section 345, and the bottom of the connecting section 345 is connected to a diffuser section 346. The cross-sectional area of ​​the diffuser section 346 decreases from large to small from top to bottom. As the cross-sectional area increases from small to large, the speed decreases from large to small, and the pressure increases from low to high. A discharge pipe 347 is installed at the bottom of the diffuser section 346, and the discharge pipe 347 is convenient for connecting pipelines.

[0041] In this embodiment, the steam in the second steam pipeline 2 enters the first drying cylinder group 31 for use, and at the same time flows into the first flash tank 32 through the pipeline. Condensed water and tail steam are generated in the first flash tank 32. The condensed water is discharged through the first condensed water pump 33, and the tail steam is connected to the side of the first heat pump 34 through the pipeline. At this time, the high-pressure steam in the first steam pipeline 1 is discharged into the first heat pump 34. When passing through the steam access pipe 343, the tail steam of the first flash tank 32 is sucked into the mixing box 341 from the tail steam access pipe 342 due to the pressure difference. The tail steam and the high-pressure steam are mixed in the mixing box 341. At the same time, the flow rate increases when passing through the speed-up section 344, and the pressure decreases when passing through the expansion section 346, so that the mixed steam becomes normal steam for use. Through the multi-stage circulation operation of the second drying component 4 and the third drying component 5, the steam is fully utilized. At the same time, the steam generated at the outlet of the first heat pump 34 is returned to the front second drying cylinder group 41 through the first connecting pipe 35 for steam intake and use, and the steam generated at the outlet of the second heat pump 44 is returned to the front third drying cylinder group 51 through the second connecting pipe 45 for steam intake and use. Finally, the tail steam condensed in the total condensate tank 6 is recovered through the heat exchanger, and after the clean water is added, it is used as warm water for wet spray water in the papermaking process. The condensed water in the total condensate tank 6 is pumped out by the total condensate pump 7, and the condensed water is returned to the thermal power department for reheating to generate fresh steam, saving resources.

[0042] The above specific embodiment is only an optional embodiment of the present invention. Based on the technical solution of the present invention and the relevant inspiration of the above embodiment, those skilled in the art can make various alternative improvements and combinations to the above specific embodiment.

Claims

1. An energy-saving steam circulation system, characterized in that: include: A first steam pipeline (1) and a second steam pipeline (2), wherein the steam pressure in the first steam pipeline (1) is greater than the steam pressure in the second steam pipeline (2); A multi-stage circulation structure, the multi-stage circulation structure comprising a first drying component (3), a second drying component (4) and a third drying component (5), wherein the first drying component (3), the second drying component (4) and the third drying component (5) are all connected to the first steam pipeline (1) and the second steam pipeline (2) through pipelines; It also includes a total condensation tank (6) and a total condensation water pump (7), wherein the third drying component (5) is connected to the total condensation tank (6) via a pipeline, and a pipeline is also connected between the total condensation tank (6) and the total condensation water pump (7).

2. The energy-saving steam cycle system according to claim 1, characterized in that: The first drying component (3) comprises a first drying cylinder group (31), a first flash tank (32), a first condensate pump (33), and a first heat pump (34); the first drying cylinder group (31) is connected to the second steam pipeline (2) via a pipeline; the first drying cylinder group (31) and the first condensate pump (33) are both connected to the first flash tank (32) via a pipeline; and the first steam pipeline (1), the first drying cylinder group (31), and the first flash tank (32) are all connected to the first heat pump (34) via a pipeline.

3. An energy-saving steam cycle system according to claim 2, characterized in that: The second drying component (4) comprises a second drying cylinder group (41), a second flash tank (42), a second condensate pump (43), and a second heat pump (44); the second drying cylinder group (41) is connected to the second steam pipeline (2) via a pipeline; the second drying cylinder group (41) and the second condensate pump (43) are both connected to the second flash tank (42) via a pipeline; and the first steam pipeline (1), the second drying cylinder group (41), and the second flash tank (42) are all connected to the second heat pump (44) via a pipeline.

4. The energy-saving steam cycle system according to claim 3, characterized in that: The third drying component (5) comprises a third drying cylinder group (51), a third flash tank (52), a third condensate pump (53), and a third heat pump (54); the third drying cylinder group (51) is connected to the second steam pipeline (2) via a pipeline; the third drying cylinder group (51) and the third condensate pump (53) are both connected to the third flash tank (52) via a pipeline; and the first steam pipeline (1), the third drying cylinder group (51), and the third flash tank (52) are all connected to the third heat pump (54) via a pipeline.

5. The energy-saving steam cycle system according to claim 3, characterized in that: The first drying assembly (3) further comprises a first connecting pipe (35) connected to the pipeline between the first drying cylinder group (31) and the first heat pump (34) and the second steam pipeline (2) and the pipeline between the second drying cylinder group (41).

6. The energy-saving steam cycle system according to claim 4, characterized in that: The second drying assembly (4) further comprises a second connecting pipe (45) connected to the pipeline between the second drying cylinder group (41) and the second heat pump (44) and the pipeline between the second steam pipeline (2) and the third drying cylinder group (51).

7. The energy-saving steam cycle system according to claim 4, characterized in that: The third heat pump (54) and the second heat pump (44) have the same structure as the first heat pump (34).

8. The energy-saving steam cycle system according to claim 7, characterized in that: The first heat pump (34) comprises a mixing box (341), to which a tail steam inlet pipe (342) and a steam inlet pipe (343) arranged perpendicular to each other are connected, and the diameter of one end of the steam inlet pipe (343) close to the mixing box (341) gradually decreases.

9. The energy-saving steam cycle system according to claim 8, characterized in that: A speed-up section (344) is also installed at the bottom of the mixing box (341), the bottom of the speed-up section (344) is connected to a connecting section (345), the bottom of the connecting section (345) is connected to a diffuser section (346), the bottom of the diffuser section (346) is installed with a discharge pipe (347), and the cross-sectional area of ​​the diffuser section (346) decreases from top to bottom.

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