Multi-stage waste heat recovery device for steam turbine of thermal power plant

Abstract

The utility model relates to the technical field of waste heat recovery of steam turbines for thermal power generation, in particular to a multistage waste heat recovery device of a steam turbine for a thermal power plant, which is characterized in that a heat exchange tank internally comprises a first chamber and a second chamber which are arranged up and down and are communicated with each other, and the upper end of the first chamber is connected with the exhaust end of the steam turbine; a first heat exchange pipe is arranged in the first cavity and is of a variable-diameter spiral structure, the diameter of the upper end of the variable-diameter spiral structure is larger than that of the lower end of the variable-diameter spiral structure, the upper end of the first heat exchange pipe penetrates through the first cavity and is provided with a water inlet, and a plurality of second heat exchange pipes are arranged in the second cavity. The upper ends of the second heat exchange pipes are communicated with the first heat exchange pipe, a plurality of condensation fins are arranged on the outer side of each second heat exchange pipe, the lower ends of the second heat exchange pipes are converged to form a converging pipe, the converging pipe penetrates through the second cavity and is provided with a water outlet, and a water drainage opening is formed in the bottom of the heat exchange tank.

Description

Technical Field

[0001] This utility model relates to the field of waste heat recovery technology of steam turbines in thermal power generation, and more specifically, to a multi-stage waste heat recovery device for steam turbines in thermal power plants. Background Technology

[0002] In modern thermal power plants, steam turbines, as one of the core pieces of equipment, inevitably generate large amounts of high-temperature steam during operation. This steam carries enormous thermal energy and is a crucial medium in the power generation process. However, existing technologies primarily employ two common methods to handle this high-temperature steam: direct venting and condensation recovery. Neither direct venting nor condensation recovery effectively recovers the waste heat energy from the steam. This not only leads to a decrease in the energy utilization efficiency of thermal power plants but also exacerbates the waste of energy resources.

[0003] Existing technologies also include dedicated waste heat recovery equipment to recover waste heat from the high-temperature steam generated by steam turbines. This involves passing a refrigerant liquid medium into a heat exchange container, allowing the refrigerant liquid medium to exchange heat with the high-temperature steam to recover waste heat. However, the limited contact area between the refrigerant liquid medium and the high-temperature steam, along with insufficient heat exchange efficiency, results in low final waste heat recovery efficiency and an unsatisfactory waste heat recovery effect. Utility Model Content

[0004] This invention aims to overcome the shortcomings of existing technologies in terms of low efficiency and unsatisfactory waste heat recovery from high-temperature steam generated by steam turbines, and to provide a multi-stage waste heat recovery device for steam turbines in thermal power plants that can solve the above problems.

[0005] A multi-stage waste heat recovery device for steam turbines in thermal power plants includes a heat exchange tank. The heat exchange tank includes a first chamber and a second chamber arranged vertically and interconnected. The upper end of the first chamber is connected to the exhaust end of the steam turbine. A first heat exchange tube is installed in the first chamber. The first heat exchange tube has a variable diameter spiral structure, with the upper diameter of the spiral structure being larger than that of the lower end. The upper end of the first heat exchange tube passes through the first chamber and is provided with a water inlet. A plurality of second heat exchange tubes are installed in the second chamber. The upper ends of the second heat exchange tubes are connected to the first heat exchange tubes. A plurality of condensing fins are provided on the outer side of each second heat exchange tube. The lower ends of the plurality of second heat exchange tubes converge to form a manifold. The manifold passes through the second chamber and is provided with a water outlet. A drain outlet is provided at the bottom of the heat exchange tank.

[0006] Furthermore, a third chamber is provided between the first chamber and the second chamber, and a third heat exchange tube is provided in the third chamber. The third heat exchange tube has a variable diameter spiral structure, and the upper end of the spiral structure has a larger diameter than the lower end. The inner diameter of the third heat exchange tube is smaller than the inner diameter of the first heat exchange tube. The upper and lower ends of the third heat exchange tube are respectively connected to the first heat exchange tube and the second heat exchange tube.

[0007] Furthermore, the third chamber is provided with two third heat exchange tubes, which have the same structure and are arranged vertically.

[0008] Furthermore, a water collection chamber is provided below the second chamber, and the drain outlet is connected to the water collection chamber.

[0009] Furthermore, the water inlet is equipped with a water inlet pipe.

[0010] Furthermore, it also includes a return pipe, the two ends of which are connected to the bottom of the water collection chamber and the water inlet pipe, respectively, and a water pump is installed on the return pipe.

[0011] Furthermore, the first chamber and the third chamber are separated by a first partition, which has an inverted conical structure and a first through hole at its lower end.

[0012] Furthermore, a first connecting pipe is provided between the first heat exchange tube and the third heat exchange tube, and the first connecting pipe passes through the first through hole.

[0013] Furthermore, the third chamber is separated from the second chamber by a second partition, which has an inverted conical structure and a second through hole at its lower end.

[0014] Furthermore, a second connecting pipe is provided between the third heat exchange tube and the second heat exchange tube. The second connecting pipe passes through the second through hole. The second heat exchange tubes are distributed in a ring array on the outer side of the lower end of the second connecting pipe. The inner diameter of the second heat exchange tube is smaller than the inner diameter of the third heat exchange tube.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] This utility model discloses a multi-stage waste heat recovery device for steam turbines in thermal power plants. It achieves primary waste heat recovery by installing a first heat exchange tube inside a first chamber and introducing waste heat recovery water into the first heat exchange tube, allowing the water to exchange heat with the high-temperature steam generated by the turbine within the first chamber. Secondary waste heat recovery is achieved by installing multiple second heat exchange tubes in a second chamber, each with multiple condensing fins on its outer side. The high-temperature steam liquefies and releases heat at the condensing fins, and the heat absorbed by the condensing fins is transferred to the waste heat recovery water in the second heat exchange tubes, allowing the water to absorb the heat released during the liquefaction of the high-temperature steam. Through this multi-stage heat exchange structure within the first and second chambers, multi-stage waste heat recovery of the high-temperature steam generated by the turbine is achieved, thus improving the efficiency of waste heat recovery.

[0017] The multi-stage waste heat recovery device for steam turbines in thermal power plants of this utility model sets up a third chamber between the first and second chambers, and sets up a third heat exchange tube in the third chamber, so that the waste heat recovery water can exchange heat with the high-temperature steam generated by the steam turbine again in the third chamber, thus fully recovering the waste heat. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0019] Figure 1 This is a schematic diagram of the overall structure of the multi-stage waste heat recovery device for steam turbines in thermal power plants according to this utility model.

[0020] Figure 2 This is a schematic diagram of the internal structure of the multi-stage waste heat recovery device for steam turbines in thermal power plants, as described in this utility model.

[0021] Figure 3 This is a schematic diagram of the structure of the second heat exchange tube in this utility model.

[0022] Figure 4 This is a schematic diagram of the structure of the third heat exchange tube in this utility model.

[0023] In the diagram: 1. Heat exchange tank; 2. First chamber; 3. Second chamber; 4. First heat exchange tube; 5. Second heat exchange tube; 6. Condensation fins; 7. Manifold; 8. Outlet; 9. Drain; 10. Third chamber; 11. Third heat exchange tube; 12. Water collection chamber; 13. Inlet pipe; 14. Return pipe; 15. Water pump; 16. First baffle; 17. First connecting pipe; 18. Second baffle; 19. Second connecting pipe. Detailed Implementation

[0024] 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.

[0025] like Figure 1 , Figure 2 As shown, the multi-stage waste heat recovery device for steam turbines in a thermal power plant in this embodiment includes a heat exchange tank 1. The heat exchange tank 1 includes a first chamber 2 and a second chamber 3 arranged vertically and interconnected. The upper end of the first chamber 2 is connected to the exhaust end of the steam turbine. A first heat exchange tube 4 is installed in the first chamber 2. The first heat exchange tube 4 has a variable diameter spiral structure, with the upper diameter of the spiral structure being larger than the lower diameter. The upper end of the first heat exchange tube 4 penetrates the first chamber 2 and is provided with a water inlet, which is equipped with a water inlet pipe 13. Multiple second heat exchange tubes 5 are installed in the second chamber 3, such as... Figure 3 As shown, the upper end of the second heat exchange tube 5 is connected to the first heat exchange tube 4. Each second heat exchange tube 5 has multiple condensing fins 6 on its outer side. The lower ends of the multiple second heat exchange tubes 5 converge into a manifold 7. The manifold 7 passes through the second chamber 3 and is provided with a water outlet 8. The bottom of the heat exchange tank 1 is provided with a drain outlet 9.

[0026] By installing a first heat exchange tube 4 inside the first chamber 2 and introducing waste heat recovery water into the first heat exchange tube 4, the waste heat recovery water exchanges gas-liquid heat with the high-temperature steam generated by the steam turbine in the first chamber 2, achieving primary waste heat recovery. By installing multiple second heat exchange tubes 5 in the second chamber 3, and installing multiple condensing fins 6 on the outside of each second heat exchange tube 5, the high-temperature steam liquefies and releases heat at the condensing fins 6. The heat absorbed by the condensing fins 6 is transferred to the waste heat recovery water in the second heat exchange tubes 5, allowing the waste heat recovery water to absorb the heat released during the liquefaction of the high-temperature steam, achieving secondary waste heat recovery. Through the multi-stage heat exchange structure in the first chamber 2 and the second chamber 3, multi-stage waste heat recovery of the high-temperature steam generated by the steam turbine is achieved, and the efficiency of waste heat recovery is improved.

[0027] In this embodiment, the first heat exchange tube 4 has a variable diameter spiral structure and is coiled in the first chamber 2. On the one hand, it can reduce the flow rate and increase the heat exchange time between the waste heat recovery water and the high-temperature steam generated by the turbine. On the other hand, it can increase the heat exchange area between the waste heat recovery water and the high-temperature steam generated by the turbine, thereby making the heat exchange more complete.

[0028] In this embodiment, a third chamber 10 is provided between the first chamber 2 and the second chamber 3, and a third heat exchange tube 11 is provided in the third chamber 10, such as... Figure 4As shown, the third heat exchange tube 11 has a variable diameter spiral structure with the upper end diameter being larger than the lower end. The inner diameter of the third heat exchange tube 11 is smaller than the inner diameter of the first heat exchange tube 4. The upper and lower ends of the third heat exchange tube 11 are connected to the first heat exchange tube 4 and the second heat exchange tube 5, respectively.

[0029] Preferably, two third heat exchange tubes 11 are provided in the third chamber 10. The two third heat exchange tubes 11 have the same structure and are arranged vertically. A first connecting pipe 17 is provided between the first heat exchange tube 4 and the third heat exchange tubes 11. The upper end of the first connecting pipe 17 is connected to the lower end of the first heat exchange tube 4, and the lower end of the first connecting pipe 17 is connected to the upper ends of the two third heat exchange tubes 11. By setting the third chamber 10 between the first chamber 2 and the second chamber 3, and installing the third heat exchange tubes 11 in the third chamber 10, the waste heat recovery water can undergo gas-liquid heat exchange with the high-temperature steam generated by the turbine in the third chamber 10 again, so as to fully recover the waste heat.

[0030] In this embodiment, a water collection chamber 12 is provided below the second chamber 3, and the drain outlet 9 is connected to the water collection chamber 12. The multi-stage waste heat recovery device for steam turbines in this embodiment also includes a return pipe 14, with both ends connected to the bottom of the water collection chamber 12 and the inlet pipe 13, respectively. A water pump 15 is installed on the return pipe 14. By setting up the return pipe 14, the condensate from the high-temperature steam generated by the steam turbine can be collected into the waste heat recovery water for energy recovery and reuse. Excess condensate can be discharged through the drain outlet 9.

[0031] In this embodiment, the first chamber 2 and the third chamber 10 are separated by a first partition 16. The first partition 16 has an inverted conical structure and a first through hole at its lower end, through which the first connecting pipe 17 passes. The third chamber 10 and the second chamber 3 are separated by a second partition 18. The second partition 18 has an inverted conical structure and a second through hole at its lower end. A second connecting pipe 19 is provided between the third heat exchange tube 11 and the second heat exchange tube 5. The second connecting pipe 19 passes through the second through hole. The second heat exchange tubes 5 are arranged in a ring array on the outer side of the lower end of the second connecting pipe 19. The inner diameter of the second heat exchange tube 5 is smaller than the inner diameter of the third heat exchange tube 11.

[0032] Preferably, the second heat exchange tube 5 has a U-shaped structure, and the condensing fins 6 are arranged in the main body of the second heat exchange tube 5, with multiple condensing fins 6 arranged at equal intervals. By distributing the second heat exchange tubes 5 in a ring array, the second heat exchange tubes 5 are evenly distributed in the second chamber 3, so that the heat dissipation fins are in uniform contact with the steam, and the steam is better and more evenly dissipated and condensed, thereby allowing the waste heat recovery water to more evenly absorb the heat released during the high-temperature steam liquefaction process.

[0033] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A multi-stage recovery device for recovering waste heat from a steam turbine of a thermal power plant, characterized in that, The application relates to a heat exchange tank (1) comprising a first chamber (2) and a second chamber (3) arranged in sequence and communicated with each other, wherein the upper end of the first chamber (2) is connected with the exhaust end of a steam engine, a first heat exchange pipe (4) is arranged in the first chamber (2), the first heat exchange pipe (4) has a variable-diameter spiral structure and the diameter of the upper end of the spiral structure is larger than that of the lower end, the upper end of the first heat exchange pipe (4) penetrates through the first chamber (2) and is provided with a water inlet, a plurality of second heat exchange pipes (5) are arranged in the second chamber (3), the upper end of each second heat exchange pipe (5) is communicated with the first heat exchange pipe (4), a plurality of condensing fins (6) are arranged outside each second heat exchange pipe (5), the lower ends of the plurality of second heat exchange pipes (5) are gathered into a collecting pipe (7), the collecting pipe (7) penetrates through the second chamber (3) and is provided with a water outlet (8), and the bottom of the heat exchange tank (1) is provided with a drain outlet (9).

2. The multi-stage power plant steam turbine waste heat recovery device according to claim 1, characterized in that, A third chamber (10) is arranged between the first chamber (2) and the second chamber (3), a third heat exchange pipe (11) is arranged in the third chamber (10), the third heat exchange pipe (11) has a variable-diameter spiral structure and the diameter of the upper end of the spiral structure is larger than that of the lower end, the inner diameter of the third heat exchange pipe (11) is smaller than that of the first heat exchange pipe (4), and the upper and lower ends of the third heat exchange pipe (11) are respectively communicated with the first heat exchange pipe (4) and the second heat exchange pipe (5).

3. The multi-stage power plant steam turbine waste heat recovery device according to claim 2, characterized in that, Two third heat exchange pipes (11) are arranged in the third chamber (10) and arranged in sequence.

4. The multi-stage power plant steam turbine waste heat recovery device according to claim 3, characterized in that, A water collecting chamber (12) is arranged below the second chamber (3), and the drain outlet (9) is communicated with the water collecting chamber (12).

5. The multi-stage power plant steam turbine waste heat recovery device according to claim 4, characterized in that, The water inlet is provided with a water inlet pipe (13).

6. The multi-stage power plant steam turbine waste heat recovery device according to claim 5, characterized by, A return pipe (14) is further arranged, the two ends of the return pipe (14) are respectively communicated with the bottom of the water collecting chamber (12) and the water inlet pipe (13), and a water pump (15) is arranged on the return pipe (14).

7. The multi-stage power plant steam turbine waste heat recovery device according to claim 6, characterized by, The first chamber (2) and the third chamber (10) are separated by a first partition plate (16), the first partition plate (16) has an inverted conical structure, and the lower end of the first partition plate (16) is provided with a first through hole.

8. The multi-stage power plant steam turbine waste heat recovery device according to claim 7, characterized in that, A first connecting pipe (17) is arranged between the first heat exchange pipe (4) and the third heat exchange pipe (11), and the first connecting pipe (17) penetrates through the first through hole.

9. The multi-stage power plant steam turbine waste heat recovery device according to claim 8, characterized by, The third chamber (10) and the second chamber (3) are separated by a second partition plate (18), the second partition plate (18) has an inverted conical structure, and the lower end of the second partition plate (18) is provided with a second through hole.

10. The multi-stage power plant steam turbine waste heat recovery device according to claim 9, characterized by, A second connecting pipe (19) is arranged between the third heat exchange pipe (11) and the second heat exchange pipe (5), the second connecting pipe (19) penetrates through the second through hole, the second heat exchange pipes (5) are arranged in an annular array form outside the lower end of the second connecting pipe (19), and the inner diameter of the second heat exchange pipe (5) is smaller than that of the third heat exchange pipe (11).

Images