Back pressure turbine with energy ladder utilization

Abstract

The utility model relates to back pressure steam turbine technical field, specifically is a kind of energy ladder utilization's back pressure steam turbine, including body and fixed on the steam turbine exhaust pipe of body, steam turbine exhaust pipe is fixedly connected with inlet pipe, and inlet pipe is connected with ladder heat exchange mechanism, and ladder heat exchange mechanism includes inlet pipe box and shell, inlet pipe is communicated with the inside of one inlet pipe box, and shell is installed on inlet pipe box, and the end of shell away from inlet pipe box is communicated with outlet pipe box, and pipe pass cross-over pipe is installed between adjacent two inlet pipe boxes, outlet pipe boxes, shell pass cross-over pipe is fixed between adjacent two shells, outlet pipe box is communicated with drain pipe, and several inlet pipe boxes are communicated with the inside of exhaust pipe;Adjacent mechanism is connected by pipe pass cross-over pipe to inlet, outlet pipe box and realizes exhaust series connection conveying, and shell pass cross-over pipe is connected shell and realizes shell pass fluid flow, and the whole can realize the ladder type heat recovery and efficient heat exchange of steam turbine exhaust.

Description

Technical Field

[0001] This utility model relates to a back-pressure steam turbine, specifically a back-pressure steam turbine that utilizes energy tiers, and belongs to the technical field of back-pressure steam turbines. Background Technology

[0002] Back-pressure steam turbines, as core equipment for achieving efficient conversion of thermal energy into mechanical energy in the industrial field, operate on the principle of: high-temperature, high-pressure steam expands and performs work through the turbine unit, converting the steam's thermal energy into the mechanical energy to drive the load; the exhaust steam, after performing work, is not directly discarded but instead recovers its waste heat through a matching heat exchange system, ultimately achieving a cascaded energy utilization model of "steam performing work - exhaust steam waste heat reuse." This equipment is widely used in industrial scenarios requiring continuous energy supply and high energy-saving demands, such as chemical production, combined heat and power generation, and urban district heating.

[0003] However, the back-pressure exhaust steam transported by the existing steam turbine exhaust pipe usually enters a single heat exchanger directly, and completes the heat exchange process with the low-temperature heat exchange medium in one go. Due to the large temperature gradient of the exhaust steam, the single-stage heat exchange can only heat the medium to a single temperature range, and cannot match different heat demand according to the exhaust steam temperature gradient. This leads to the energy mismatch problem of heating the low-temperature demand medium with high-temperature exhaust steam. The high-value high-temperature waste heat in the exhaust steam is not utilized in a targeted manner and is eventually discharged directly with the low-temperature exhaust steam, resulting in a low waste heat recovery rate. Utility Model Content

[0004] The purpose of this invention is to provide a back-pressure steam turbine that utilizes energy in a stepped manner to solve the above problems. The exhaust steam is transported in series between adjacent mechanisms by connecting the inlet and outlet tube boxes through the tube-side crossover pipe, and the shell-side fluid flows through connecting the shell through the shell-side crossover pipe. The turbine exhaust steam can be recovered in a stepped manner and the heat exchange can be achieved as a whole.

[0005] This utility model achieves the above-mentioned objective through the following technical solution: a back-pressure steam turbine utilizing energy tiers, comprising a casing and a steam turbine exhaust pipe fixed to the casing, an inlet pipe fixedly connected to the steam turbine exhaust pipe, a stepped heat exchange mechanism connected to the inlet pipe, and interconnections between adjacent stepped heat exchange mechanisms, the stepped heat exchange mechanism comprising an inlet tube box and a shell, one end of the inlet pipe away from the steam turbine exhaust pipe communicating with the interior of an inlet tube box, a shell mounted on the inlet tube box, one end of the shell away from the inlet tube box communicating with an outlet tube box, a tube-side crossover pipe installed between adjacent inlet tube boxes and outlet tube boxes, a shell-side crossover pipe fixed between adjacent shells, a drain pipe connected to the outlet tube box, and several inlet tube boxes communicating with the interior of the exhaust pipe.

[0006] Preferably, the inlet pipe box is a cylindrical sealed chamber, and the inlet pipe box is sealed to the steam inlet pipe or the pipe-side crossover pipe through a flange. The open end of the inlet pipe box is rigidly fixed to the shell by bolts.

[0007] Preferably, the shell is a cylindrical body, and both ends of the shell are sealed to the inlet pipe box and the outlet pipe box respectively through flanges.

[0008] Preferably, the outlet pipe box and the inlet pipe box are symmetrical in structure, both being cylindrical sealed chambers, and the drain pipe is welded to the bottom of the outlet pipe box.

[0009] Preferably, the two ends of the pipe-side jumper are respectively sealed to the outlet pipe box of the preceding shell and the inlet pipe box of the following shell via flanges, and the two ends of the shell-side jumper are respectively connected to the shell-side outlet end of the preceding shell and the shell-side inlet end of the following shell.

[0010] Preferably, several of the housings are installed in a fixing mechanism, which includes a tray and a support frame. The housings are engaged with the tray and the clamping plate, and the support frame is fixedly connected to the tray.

[0011] Preferably, the fixing mechanism further includes insert blocks, both ends of the card plate are fixedly connected to insert blocks, the tray has a slot, the slot is fitted with insert blocks, and the insert blocks are fixedly connected to the tray by bolts.

[0012] Preferably, the portion of the card plate or tray that contacts the housing has an arc-shaped structure, and the insert block and the tray are engaged and connected.

[0013] The beneficial effects of this utility model are as follows: the shell provides ample flow space for the shell-side fluid, and the bottom-inlet, top-outlet flow channel design ensures that the shell-side fluid fills the shell completely; the flange sealing connection at both ends of the shell enables quick docking with the inlet and outlet pipe boxes, while ensuring complete isolation between the tube side and the shell side, avoiding equipment failure caused by the mixing of the two media; the drain pipe welded to the bottom of the outlet pipe box can promptly discharge the condensate generated after the exhaust steam is cooled, preventing condensate from accumulating in the tube side and ensuring long-term stable flow of the tube-side fluid. Simultaneously, the recovered condensate can be reused, achieving water conservation; the tube-side crossover pipe enables the series connection of multiple sets of stepped heat exchange mechanisms, allowing the turbine exhaust steam to flow through each mechanism gradually at high, medium, and low temperatures, releasing heat sequentially and achieving stepped energy utilization; the shell-side crossover pipe enables the series flow of the shell-side fluid, allowing the shell-side medium to fully absorb the exhaust steam heat and improving the medium's heating efficiency. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0015] Figure 2for Figure 1 The diagram shown is an enlarged view of the structure of part A.

[0016] Figure 3 This is a schematic diagram of the connection structure between the shell and the tray of this utility model;

[0017] Figure 4 for Figure 3 The diagram shown is an enlarged view of the structure of section B.

[0018] Figure 5 This is a schematic diagram of the connection structure between the steam inlet pipe and the inlet pipe box of this utility model.

[0019] In the diagram: 1. Main body; 2. Steam inlet pipe; 3. Stepped heat exchange mechanism; 301. Inlet pipe box; 302. Shell; 303. Outlet pipe box; 304. Tube-side crossover pipe; 305. Shell-side crossover pipe; 306. Drain pipe; 307. Exhaust pipe; 4. Fixing mechanism; 401. Clamping plate; 402. Support plate; 403. Support frame; 404. Insert block; 405. Slot; 5. Steam turbine exhaust pipe. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figures 1-5As shown, a back-pressure steam turbine utilizing energy tiers includes a casing 1 and a turbine exhaust pipe 5 fixed to the casing 1. An inlet pipe 2 is fixedly connected to the turbine exhaust pipe 5, and a stepped heat exchange mechanism 3 is connected to the inlet pipe 2. Adjacent stepped heat exchange mechanisms 3 are interconnected. Each stepped heat exchange mechanism 3 includes an inlet tube box 301 and a shell 302. One end of the inlet pipe 2 away from the turbine exhaust pipe 5 is connected to the interior of an inlet tube box 301. A shell 302 is installed on the inlet tube box 301, and one end of the shell 302 away from the inlet tube box 301 is connected to an outlet tube box 303. A tube-side crossover pipe 304 is installed between adjacent inlet tube boxes 301 and outlet tube boxes 303. High-temperature exhaust steam from the first inlet tube box 301... The steam first enters the corresponding shell 302 to complete the initial heat exchange, and after cooling, flows into the outlet tube box 303 of the mechanism. Subsequently, the medium-temperature exhaust steam in the outlet tube box 303 flows into the inlet tube box 301 of the next stepped heat exchange mechanism 3 through the tube-side crossover pipe 304. The two ends of the tube-side crossover pipe 304 are sealed to the outlet tube box 303 of the previous mechanism and the inlet tube box 301 of the next mechanism through flanges respectively. According to this logic, the exhaust steam flows through all the stepped heat exchange mechanisms 3 in sequence, and finally forms a stepped temperature gradient of high-temperature exhaust steam, medium-temperature exhaust steam, and low-temperature exhaust steam. A shell-side crossover pipe 305 is fixed between two adjacent shells 302, a drain pipe 306 is connected to the outlet tube box 303, and several inlet tube boxes 301 are all connected to the interior of the exhaust pipe 307.

[0022] As a technical optimization of this utility model, the inlet pipe box 301 is a cylindrical sealed chamber. The inlet pipe box 301 is sealed to the steam inlet pipe 2 or the pipe-side crossover pipe 304 through a flange. The open end of the inlet pipe box 301 is rigidly fixed to the shell 302 by bolts. The shell 302 is a cylindrical cylinder. The two ends of the shell 302 are sealed to the inlet pipe box 301 and the outlet pipe box 303 through flanges respectively. The back pressure exhaust steam in the turbine exhaust pipe 5 flows to the steam inlet pipe 2 through the pipeline. The steam inlet pipe 2 is fixedly connected to the turbine exhaust pipe 5, which can form a continuous conveying channel. Finally, the steam flows from the end of the steam inlet pipe 2 away from the turbine exhaust pipe 5 into the inlet pipe box 301 of the first stepped heat exchange mechanism 3. The outlet pipe box 303 is symmetrical to the inlet pipe box 301 in structure. Both are cylindrical sealed chambers, and the drain pipe 306 is welded to the bottom of the outlet pipe box 303.

[0023] As a technical optimization of this utility model, the two ends of the tube-side crossover pipe 304 are respectively sealed to the outlet pipe box 303 of the previous shell 302 and the inlet pipe box 301 of the subsequent shell 302 via flanges. The two ends of the shell-side crossover pipe 305 are respectively connected to the shell-side outlet of the previous shell 302 and the shell-side inlet of the subsequent shell 302. The low-temperature heat exchange medium is drawn from the storage tank and connected to the shell-side inlet of the first stepped heat exchange mechanism 3 shell 302 through a pipeline, so that the medium slowly flows into the shell-side space of the shell 302. The low-temperature medium in the shell-side of the first shell 302 absorbs the waste heat of the tube-side exhaust steam and then heats up. The medium then flows out from the shell-side outlet of the shell 302; the outflowing medium flows into the shell-side inlet of the next shell 302 through the shell-side crossover pipe 305; following this logic, the heat exchange medium flows through the shell side of all shells 302 in sequence, and finally flows out from the outlet of the last shell 302; in each set of stepped heat exchange mechanism 3, the tube-side exhaust steam flows in the heat exchange tubes inside the shell 302, and the shell-side medium flows in the shell-side space outside the heat exchange tubes; the two fluids are in indirect contact through the heat exchange tube walls, and the residual heat of the tube-side exhaust steam is transferred to the shell-side medium through the tube walls, realizing the heat exchange process of exhaust steam cooling and medium heating.

[0024] As a technical optimization of this utility model, several housings 302 are installed in a fixing mechanism 4. The fixing mechanism 4 includes a support plate 402 and a support frame 403. The housings 302 are engaged with the support plate 402 and the clamping plate 401. The support frame 403 is fixedly connected to the support plate 402. Insert blocks 404 are fixedly connected to both ends of the clamping plate 401. The support plate 402 has a slot 405, and the insert blocks 404 are engaged with the slot 405. The insert blocks 404 are bolted to the support plate. 402 is fixedly connected. Loosen the flange connection of the tube-side crossover pipe 304 and the shell-side crossover pipe 305. A certain set of stepped heat exchange mechanism 3 can be removed individually. Unscrew the fixing bolts of the insert block 404 and the support plate 402. After removing the clamping plate 401, the shell 302 can be inspected or worn flange gaskets, drain pipes 306 and other components can be replaced without disassembling the entire equipment. The parts of the clamping plate 401 and the support plate 402 that contact the shell 302 are set with an arc surface structure. The insert block 404 and the support plate 402 are interlocked.

[0025] In use, this invention firstly, after starting the back-pressure turbine, the steam expands and performs work in the turbine unit inside the machine body 1, forming back-pressure exhaust steam. The back-pressure exhaust steam in the turbine exhaust pipe 5 flows to the inlet pipe 2 through a pipeline. The inlet pipe 2 is fixedly connected to the turbine exhaust pipe 5, forming a continuous conveying channel. Finally, it flows from the end of the inlet pipe 2 away from the turbine exhaust pipe 5 into the inlet tube box 301 of the first stepped heat exchange mechanism 3. The high-temperature exhaust steam in the first inlet tube box 301 first enters the corresponding shell 302 to complete the first heat exchange, and after cooling, flows into the outlet tube box 303 of the mechanism. Subsequently, the medium-temperature exhaust steam in the outlet tube box 303 flows into the next step through the tube-side crossover pipe 304. The inlet pipe box 301 of each stepped heat exchange mechanism 3; the two ends of the pipe-side crossover pipe 304 are respectively sealed to the outlet pipe box 303 of the previous mechanism and the inlet pipe box 301 of the next mechanism through flanges. According to this logic, the exhaust steam flows through all the stepped heat exchange mechanisms 3 in sequence, and finally forms a stepped temperature gradient of high temperature exhaust steam, medium temperature exhaust steam, and low temperature exhaust steam. Then, according to the actual waste heat utilization needs, suitable industrial production cold water, heating circulating water, or heat transfer oil that needs to be heated is selected, and the medium is stored in an external storage tank or circulation system. The external transfer pump is started to extract the low temperature heat exchange medium from the storage tank and connect it to the shell-side water inlet end of the shell 302 of the first stepped heat exchange mechanism 3 through a pipeline, so that the medium flows slowly. Within the shell-side space of the first shell-side of the first shell-side of the shell 302, the low-temperature medium absorbs the waste heat from the exhaust steam in the tube side and heats up, then flows out from the water outlet of the shell-side of that shell 302. The outflowing medium-temperature medium flows into the water inlet of the next shell-side through the shell-side crossover pipe 305. Following this logic, the heat exchange medium flows sequentially through the shell-side of all shells 302, finally flowing out from the water outlet of the last shell 302. Within the shell 302 of each set of stepped heat exchange mechanisms 3, the exhaust steam in the tube side flows inside the heat exchange tubes inside the shell 302, while the shell-side medium flows in the shell-side space outside the heat exchange tubes. The two fluids are in indirect contact through the heat exchange tube walls, and the waste heat from the exhaust steam in the tube side is transferred to the shell-side medium through the tube walls. The tube side heat exchanger achieves a heat exchange process of cooling the exhaust steam and heating the medium. During the heat exchange process, the exhaust steam in the tube side will generate condensate due to the temperature drop. The condensate flows with the exhaust steam into the outlet tube box 303 and is deposited at the bottom of the outlet tube box 303 under the action of gravity. Then, the valve of the drain pipe 306 is opened, and the condensate is discharged through the drain pipe 306. It can be collected and reused. The back pressure exhaust steam may be mixed with a small amount of air or other non-condensable gases. These gases will not liquefy when flowing in the tube side. If they remain for a long time, they will form air resistance. Therefore, during the heat exchange process, the non-condensable gases will enter the inlet tube box 301 with the exhaust steam and be naturally discharged to the outside through the connecting channel between the inlet tube box 301 and the exhaust pipe 307.Loosen the flange connections of the tube-side jumper pipe 304 and the shell-side jumper pipe 305 to individually remove a set of stepped heat exchanger mechanisms 3. Unscrew the fixing bolts of the insert block 404 and the support plate 402, and remove the clamping plate 401 to inspect the shell 302 or replace worn flange gaskets, drain pipes 306, and other components without disassembling the entire equipment.

[0026] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0027] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A back-pressure steam turbine utilizing energy cascades, comprising a casing (1) and a steam turbine exhaust pipe (5) fixed to the casing (1), wherein an inlet pipe (2) is fixedly connected to the steam turbine exhaust pipe (5), characterized in that: The steam inlet pipe (2) is connected to a stepped heat exchange mechanism (3), and two adjacent stepped heat exchange mechanisms (3) are interconnected. The stepped heat exchange mechanism (3) includes an inlet pipe box (301) and a shell (302). The end of the steam inlet pipe (2) away from the turbine exhaust pipe (5) is connected to the interior of an inlet pipe box (301). The shell (302) is installed on the inlet pipe box (301). The end of the shell (302) away from the inlet pipe box (301) is connected to an outlet pipe box (303). A tube-side crossover pipe (304) is installed between two adjacent inlet pipe boxes (301) and outlet pipe boxes (303). A shell-side crossover pipe (305) is fixed between two adjacent shells (302). A drain pipe (306) is connected to the outlet pipe box (303). Several inlet pipe boxes (301) are all connected to the interior of the exhaust pipe (307).

2. The back-pressure steam turbine for energy cascade utilization according to claim 1, characterized in that: The inlet pipe box (301) is a cylindrical sealed chamber. The inlet pipe box (301) is sealed to the steam inlet pipe (2) or the pipe-side crossover pipe (304) through a flange. The open end of the inlet pipe box (301) is rigidly fixed to the shell (302) by bolts.

3. The back-pressure steam turbine for energy cascade utilization according to claim 1, characterized in that: The housing (302) is a cylindrical tube, and the two ends of the housing (302) are respectively sealed to the inlet pipe box (301) and the outlet pipe box (303) through flanges.

4. The back-pressure steam turbine for energy cascade utilization according to claim 1, characterized in that: The outlet pipe box (303) and the inlet pipe box (301) are structurally symmetrical, both being cylindrical sealed chambers, and the drain pipe (306) is welded to the bottom of the outlet pipe box (303).

5. A back-pressure steam turbine for energy cascade utilization according to claim 1, characterized in that: The two ends of the pipe-side jumper (304) are respectively sealed to the outlet pipe box (303) of the previous shell (302) and the inlet pipe box (301) of the next shell (302) via flanges. The two ends of the shell-side jumper (305) are respectively connected to the shell-side outlet end of the previous shell (302) and the shell-side inlet end of the next shell (302).

6. A back-pressure steam turbine for energy cascade utilization according to claim 1, characterized in that: Several housings (302) are installed in a fixing mechanism (4), which includes a support plate (402) and a support frame (403). The housings (302) are engaged with the support plate (402) and the clamping plate (401). The support frame (403) is fixedly connected to the support plate (402).

7. A back-pressure steam turbine for energy cascade utilization according to claim 6, characterized in that: The fixing mechanism (4) further includes a plug (404). Both ends of the card plate (401) are fixedly connected with plugs (404). The tray (402) is provided with a slot (405). The slot (405) is fitted with the plug (404). The plug (404) is fixedly connected to the tray (402) by bolts.

8. A back-pressure steam turbine for energy cascade utilization according to claim 7, characterized in that: The parts of the card plate (401) and the tray plate (402) that contact the housing (302) are arranged with an arc surface structure, and the insert block (404) is engaged with the tray plate (402).

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