A three-stage series heat exchanger

Abstract

The present invention discloses a three-stage series heat exchanger, which relates to the technical field of heat exchangers and includes a superheater, a vaporizer, and a high-pressure steam generator. The upper end of the shell side of the superheater is hermetically connected to the high-temperature gas inlet header, the lower end of the shell side of the superheater is hermetically connected to the upper end of the shell side of the high-pressure steam generator, the lower end of the shell side of the high-pressure steam generator is hermetically connected to the upper end of the shell side of the vaporizer, and the lower end of the shell side of the vaporizer is hermetically connected to the heat exchanger outlet connection pipe; the shell side of the superheater is internally provided with superheater heat exchange tubes, and the upper ends of the superheater heat exchange tubes are installed on the superheater inlet tube sheet; the present invention can achieve two heat exchanges between the high-temperature gas medium and a cold medium, and at the same time achieve one heat exchange with high-pressure boiler water. During the heat exchange process, the stability of the connection between each heat exchange tube inside the heat exchanger and the corresponding tube sheet can be ensured, and at the same time, erosion corrosion inside the heat exchanger at the connection is avoided, and the heat exchanger operates more stably and safely.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchangers, and in particular to a three-stage series heat exchanger. Background Art

[0002] Existing heat exchangers mostly use multiple devices for heat exchange, which have a large floor area and low compactness. Especially for heat exchanger structures with a large-diameter shell side having a two-phase flow medium, there are problems such as poor material distribution in the tube and shell sides, obvious vibration of the heat exchange tube bundle, expansion or extension of cracks, micro-cracks, and other defects at the connection between the heat exchange tube and the tube sheet. When the inlet medium of the heat exchanger is a two-phase medium, the heat exchange tubes at the inlet of the heat exchanger are severely eroded and corroded, and the erosion and corrosion caused by the two-phase flow in local areas of the heat exchanger are serious; the tube heads are severely eroded and corroded by high-temperature reaction gas, with a high risk of failure; the heat exchanger has a large size, and the leakage of the shell side medium significantly affects the heat exchange effect of the heat exchanger. Summary of the Invention

[0003] The purpose of the present invention is to solve the defects existing in the prior art, and a three-stage series heat exchanger is proposed.

[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0005] A three-stage series heat exchanger includes a superheater, a vaporizer, and a high-pressure steam generator. The upper end of the shell side of the superheater is hermetically connected to the high-temperature gas inlet header, the lower end of the shell side of the superheater is hermetically connected to the upper end of the shell side of the high-pressure steam generator, the lower end of the shell side of the high-pressure steam generator is hermetically connected to the upper end of the shell side of the vaporizer, and the lower end of the shell side of the vaporizer is hermetically connected to the heat exchanger outlet connection pipe;

[0006] The shell side of the superheater is internally provided with superheater heat exchange tubes. The upper ends of the superheater heat exchange tubes are installed on the superheater inlet tube sheet, and the lower ends of the superheater heat exchange tubes are installed on the superheater outlet tube sheet. The superheater inlet tube sheet and the superheater outlet tube sheet are respectively hermetically connected to the inner wall of the shell side of the superheater. One side of the shell side of the high-pressure steam generator is provided with a high-pressure steam generator shell side inlet connection pipe, and the other side is provided with a high-pressure steam generator shell side outlet connection pipe;

[0007] The upper end of the shell side of the superheater is connected to a superheater shell side outlet connection pipe, the lower end of the shell side of the superheater is connected to a superheater shell side inlet connection pipe, the superheater shell side inlet connection pipe is connected to the upper end of a connecting pipe, and the lower end of the connecting pipe is connected to the upper end of the shell side of the vaporizer through a vaporizer outlet connection pipe;

[0008] The shell side of the high-pressure steam generator is internally provided with high-pressure steam generator heat exchange tubes. The upper ends of the high-pressure steam generator heat exchange tubes are installed on the high-pressure steam generator inlet tube sheet, and the lower ends of the high-pressure steam generator heat exchange tubes are installed on the high-pressure steam generator outlet tube sheet. The high-pressure steam generator inlet tube sheet and the high-pressure steam generator outlet tube sheet are respectively hermetically connected to the inner wall of the shell side of the high-pressure steam generator;

[0009] The shell side of the vaporizer is internally provided with vaporizer heat exchange tubes. The upper ends of the vaporizer heat exchange tubes are installed on the vaporizer inlet tube sheet, and the lower ends of the vaporizer heat exchange tubes are installed on the vaporizer outlet tube sheet. The vaporizer inlet tube sheet and the vaporizer outlet tube sheet are respectively hermetically connected to the inner wall of the shell side of the vaporizer;

[0010] The lower end of the shell side of the vaporizer is connected to the vaporizer inlet connecting pipe through an annular distributor.

[0011] Further, the lower surface of the high-pressure steam generator inlet tube sheet is fixedly welded to the high-pressure steam generator heat exchange tubes. The upper surface of the high-pressure steam generator inlet tube sheet is provided with a heat insulation lining. The high-pressure steam generator inlet tube sheet and the heat insulation lining are penetrated with installation holes, and a medium distribution pipe is fixed in the installation holes. The lower end of the medium distribution pipe is fixedly inserted inside the high-pressure steam generator heat exchange tubes. The upper end of the medium distribution pipe extends to the area between the heat insulation lining and the superheater outlet tube sheet, and a cover is installed at the upper end of the medium distribution pipe. Distribution holes are opened on the side surface of the upper end of the medium distribution pipe.

[0012] Further, the annular distributor includes an outer cylinder fixedly sleeved on the outer side of the shell side of the vaporizer. Two vaporizer inlet connecting pipes are symmetrically installed on the side surface of the outer cylinder. There is an annular area between the outer cylinder and the outer side of the shell side of the vaporizer. The areas of the annular area close to the two vaporizer inlet connecting pipes are fluid diffusion areas, and the area between the two fluid diffusion areas is a flow guiding area. A plurality of distribution grooves are opened on the outer wall of the shell side of the vaporizer at the position of the flow guiding area;

[0013] A spoiler is arranged between the fluid diffusion area and the flow guiding area.

[0014] Further, a plurality of baffle plates are installed on the inner wall of the shell side of the superheater and the inner wall of the shell side of the vaporizer;

[0015] The baffle plates located inside the shell side of the superheater are installed with sealing strips through bolts, and the baffle plates located inside the shell side of the vaporizer are also installed with sealing strips through bolts.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] The present invention can achieve two - stage heat exchange between a high - temperature gas medium and a cold medium, and at the same time achieve one - stage heat exchange with high - pressure boiler water. During the heat - exchange process, the stability of the connection between each heat - exchange tube and the corresponding tube sheet inside the heat exchanger can be ensured, and at the same time, erosion - corrosion inside the heat exchanger at the connection is avoided, making the operation of the heat exchanger more stable and safe. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, and do not constitute a limitation to the present invention.

[0019] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 is a schematic diagram of the overall structure of the present invention;

[0021] Figure 3 is a schematic diagram of the overall structure of the present invention;

[0022] Figure 4 is a schematic diagram of the overall structure of the present invention;

[0023] Figure 5 is a schematic diagram of the overall structure of the present invention.

[0024] In the figure: 1 high - temperature gas inlet header, 2 superheater shell - side outlet nozzle, 3 superheater, 4 superheater shell - side inlet nozzle, 5 connecting pipe, 6 vaporizer outlet nozzle, 7 vaporizer, 70 vaporizer heat - exchange tubes, 71 outer cylinder, 72 fluid diffusion zone, 73 diversion zone, 74 turbulator, 75 distribution groove, 8 baffle plate, 81 sealing strip, 82 bolt, 9 vaporizer inlet nozzle, 10 heat - exchanger outlet nozzle, 11 vaporizer outlet tube sheet, 12 vaporizer inlet tube sheet, 13 high - pressure steam generator outlet tube sheet, 14 high - pressure steam generator, 141 high - pressure steam generator heat - exchange tubes, 142 medium distribution pipe, 143 distribution holes, 144 cover, 15 high - pressure steam generator inlet tube sheet, 151 heat - insulating lining, 16 superheater outlet tube sheet, 17 superheater inlet tube sheet, 18 high - pressure steam generator shell - side inlet nozzle, 19 high - pressure steam generator shell - side outlet nozzle;

[0025] 101 high - temperature gas inlet medium, 102 high - temperature gas outlet medium, 103 cold medium, 104 superheated gas, 105 high - pressure boiler feed water, 106 high - pressure steam. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention;

[0027] Refer to Figures 1-5, A three-stage series heat exchanger, including a superheater 3, a vaporizer 7, and a high-pressure steam generator 14. The upper end of the shell side of the superheater 3 is hermetically connected to the high-temperature gas inlet header 1. The lower end of the shell side of the superheater 3 is hermetically connected to the upper end of the shell side of the high-pressure steam generator 14. The lower end of the shell side of the high-pressure steam generator 14 is hermetically connected to the upper end of the shell side of the vaporizer 7. The lower end of the shell side of the vaporizer 7 is hermetically connected to the heat exchanger outlet connection pipe 10;

[0028] The shell side of the superheater 3 is internally provided with superheater heat exchange tubes. The upper ends of the superheater heat exchange tubes are installed on the superheater inlet tube sheet 17, and the lower ends of the superheater heat exchange tubes are installed on the superheater outlet tube sheet 16. The superheater inlet tube sheet 17 and the superheater outlet tube sheet 16 are respectively hermetically connected to the inner wall of the shell side of the superheater 3;

[0029] The upper end of the shell side of the superheater 3 is connected to the superheater shell side outlet connection pipe 2, and the lower end of the shell side of the superheater 3 is connected to the superheater shell side inlet connection pipe 4. The superheater shell side inlet connection pipe 4 is connected to the upper end of the connecting pipe 5. The lower end of the connecting pipe 5 is connected to the upper end of the shell side of the vaporizer 7 through the vaporizer outlet connection pipe 6;

[0030] The shell side of the high-pressure steam generator 14 is internally provided with high-pressure steam generator heat exchange tubes 141. The upper ends of the high-pressure steam generator heat exchange tubes 141 are installed on the high-pressure steam generator inlet tube sheet 15, and the lower ends of the high-pressure steam generator heat exchange tubes 141 are installed on the high-pressure steam generator outlet tube sheet 13. The high-pressure steam generator inlet tube sheet 15 and the high-pressure steam generator outlet tube sheet 13 are respectively hermetically connected to the inner wall of the shell side of the high-pressure steam generator 14. On one side of the shell side of the high-pressure steam generator 14, there is a high-pressure steam generator shell side inlet connection pipe 18, and on the other side, there is a high-pressure steam generator shell side outlet connection pipe 19.

[0031] The shell side of the vaporizer 7 is internally provided with vaporizer heat exchange tubes 70. The upper ends of the vaporizer heat exchange tubes 70 are installed on the vaporizer inlet tube sheet 12, and the lower ends of the vaporizer heat exchange tubes 70 are installed on the vaporizer outlet tube sheet 11. The vaporizer inlet tube sheet 12 and the vaporizer outlet tube sheet 11 are respectively hermetically connected to the inner wall of the shell side of the vaporizer 7;

[0032] The lower end of the shell side of the vaporizer 7 is connected to the vaporizer inlet connection pipe 9 through an annular distributor.

[0033] The shell side material of the superheater 3 and the tube bundle material of the superheater heat exchange tubes are high-temperature resistant stainless steel; the shell side material of the high-pressure steam generator 14 and the tube bundle material of the high-pressure steam generator heat exchange tubes 141 are carbon steel; the shell side material of the vaporizer 7 and the tube bundle material of the vaporizer heat exchange tubes 70 are carbon steel;

[0034] The superheater outlet tube sheet 16 is a floating tube sheet, and the superheater inlet tube sheet 17 is a fixed tube sheet; the high-pressure steam generator inlet tube sheet 15 and the high-pressure steam generator outlet tube sheet 13 are both of arc-shaped thin tube sheet structures; the vaporizer inlet tube sheet 12 and the vaporizer outlet tube sheet 11 are of fixed tube sheet structures.

[0035] The vaporizer heat exchange tubes 70 located at the center of the heat exchange tube bundle of the vaporizer 7 are heat exchange tubes with a small wall thickness, while the vaporizer heat exchange tubes 70 near the inner wall of the shell of the vaporizer 7 adopt heat exchange tubes with a large diameter and wall thickness. However, the inner diameters of all the vaporizer heat exchange tubes 70 are kept consistent, which can improve the ability of the tube bundle to resist local erosion-corrosion in the annulus under gas-liquid two-phase flow conditions, and the equipment has high long-term effectiveness.

[0036] The lower surface of the high-pressure steam generator inlet tube sheet 15 is welded and fixed to the high-pressure steam generator heat exchange tube 141. The upper surface of the high-pressure steam generator inlet tube sheet 15 is provided with a heat insulation lining 151. The high-pressure steam generator inlet tube sheet 15 and the heat insulation lining 151 are penetrated with installation holes, and a medium distribution tube 142 is fixed in the installation holes. The lower end of the medium distribution tube 142 is fixedly inserted inside the high-pressure steam generator heat exchange tube 141. The upper end of the medium distribution tube 142 extends to the area between the heat insulation lining 151 and the superheater outlet tube sheet 16. And a cover 144 is installed at the upper end of the medium distribution tube 142. Distribution holes 143 are opened on the side surface of the upper end of the medium distribution tube 142. The aperture of the distribution holes 143 is 6 - 15 mm. The cover 144 and the medium distribution tube 142 are connected in a threaded form. The medium distribution tube 142 is made of high-temperature resistant stainless steel. It can improve the uniformity of the high-temperature gas entering the tube side of the high-pressure steam generator 14, prevent local overheating and overcooling states, and has good heat exchange effect. The cover 144 and the medium distribution tube 142 adopt a detachable threaded structure, which is convenient for maintenance.

[0037] The annular distributor includes an outer cylinder 71 fixedly sleeved on the outside of the shell side of the vaporizer 7. Two vaporizer inlet nozzles 9 are symmetrically installed on the side surface of the outer cylinder 71. There is an annular area between the outer cylinder 71 and the outside of the shell side of the vaporizer 7. The areas of the annular area near the two vaporizer inlet nozzles 9 are fluid diffusion areas 72. The area between the two fluid diffusion areas 72 is a flow guiding area 73. A plurality of distribution grooves 75 are opened on the outer wall of the shell side of the vaporizer 7 at the position corresponding to the flow guiding area 73;

[0038] A spoiler 74 is arranged between the fluid diffusion area 72 and the flow guiding area 73. The spoiler 74 is made of stainless steel. The annular distributor can improve the uniformity of the two-phase flow medium, reduce the influence of local erosion-corrosion, reduce the phase separation problem during the swirling process of the two-phase flow medium, and has high reliability.

[0039] A plurality of baffles 8 are installed on the inner wall of the shell side of the superheater 3 and the inner wall of the shell side of the vaporizer 7; the baffle 8 located inside the shell side of the superheater 3 is installed with a sealing strip 81 through bolts 82, and the baffle 8 located inside the shell side of the vaporizer 7 is also installed with a sealing strip 81 through bolts 82.

[0040] The arc length of the sealing strip 81 is the same as the contact length between the baffle 8 and the shell side of the superheater 3 and the shell side of the vaporizer 7, and the contact position is designed with an arc bend, and the bending direction is towards the medium flow direction, which can reduce the influence of the leakage flow in the shell side medium annulus on the heat transfer effect of the large-diameter heat exchanger, and the heat exchange performance of the heat exchanger is high.

[0041] Support plates are arranged in the shell side of the vaporizer 7 to assist in supporting the heat exchange tubes 70 of the vaporizer, which can effectively reduce the vibration influence of the two-phase flow medium on the heat exchange tubes 70 of the vaporizer.

[0042] The heat exchange process of the present invention is roughly as follows: the high-temperature gas inlet medium 101 first enters the high-temperature gas inlet header 1, then enters the heat exchange tubes of the superheater 3, enters the high-pressure steam generator heat exchange tubes 141 through the superheater heat exchange tubes, then enters the heat exchange tubes 70 of the vaporizer, and finally flows out of the high-temperature gas outlet medium 102 from the heat exchanger outlet nozzle 10. At the same time, the cold medium 103 enters the shell side of the vaporizer 7 from the vaporizer inlet nozzle 9 and the annular distributor, exchanges heat with the high-temperature gas inlet medium 101 flowing through the heat exchange tubes 70 of the vaporizer, and finally the cold medium 103 enters the shell side of the superheater 3 through the connecting pipe 5, exchanges heat with the high-temperature gas inlet medium 101 flowing through the superheater heat exchange tubes, and finally discharges the superheated gas 104 from the superheater shell side outlet nozzle 2; in addition, the high-pressure boiler feed water 105 flows into the shell side of the high-pressure steam generator 14 from the high-pressure steam generator shell side inlet nozzle 18, exchanges heat with the high-temperature gas inlet medium 101 flowing through the high-pressure steam generator heat exchange tubes 141, and then flows out of the high-pressure steam 106 from the high-pressure steam generator shell side outlet nozzle 19;

[0043] In summary, the present invention can achieve two heat exchanges between the high-temperature gas medium and a cold medium, and at the same time achieve one heat exchange with the high-pressure boiler water.

Claims

1. A three-stage series heat exchanger, comprising a superheater (3), a vaporizer (7), and a high-pressure steam generator (14), characterized in that, the upper end of the shell side of the superheater (3) is hermetically connected to the high-temperature gas inlet header (1), the lower end of the shell side of the superheater (3) is hermetically connected to the upper end of the shell side of the high-pressure steam generator (14), the lower end of the shell side of the high-pressure steam generator (14) is hermetically connected to the upper end of the shell side of the vaporizer (7), and the lower end of the shell side of the vaporizer (7) is hermetically connected to the heat exchanger outlet connection pipe (10); the shell side of the superheater (3) is internally provided with superheater heat exchange tubes, the upper ends of the superheater heat exchange tubes are installed on the superheater inlet tube sheet (17), the lower ends of the superheater heat exchange tubes are installed on the superheater outlet tube sheet (16), and the superheater inlet tube sheet (17) and the superheater outlet tube sheet (16) are respectively hermetically connected to the inner wall of the shell side of the superheater (3); the upper end of the shell side of the superheater (3) is connected to a superheater shell side outlet connection pipe (2), the lower end of the shell side of the superheater (3) is connected to a superheater shell side inlet connection pipe (4), the superheater shell side inlet connection pipe (4) is connected to the upper end of a connecting pipe (5), and the lower end of the connecting pipe (5) is connected to the upper end of the shell side of the vaporizer (7) through a vaporizer outlet connection pipe (6); the shell side of the high-pressure steam generator (14) is internally provided with high-pressure steam generator heat exchange tubes (141), the upper ends of the high-pressure steam generator heat exchange tubes (141) are installed on the high-pressure steam generator inlet tube sheet (15), the lower ends of the high-pressure steam generator heat exchange tubes (141) are installed on the high-pressure steam generator outlet tube sheet (13), the high-pressure steam generator inlet tube sheet (15) and the high-pressure steam generator outlet tube sheet (13) are respectively hermetically connected to the inner wall of the shell side of the high-pressure steam generator (14), and one side of the shell side of the high-pressure steam generator (14) is provided with a high-pressure steam generator shell side inlet connection pipe (18), and the other side is provided with a high-pressure steam generator shell side outlet connection pipe (19); the shell side of the vaporizer (7) is internally provided with vaporizer heat exchange tubes (70), the upper ends of the vaporizer heat exchange tubes (70) are installed on the vaporizer inlet tube sheet (12), the lower ends of the vaporizer heat exchange tubes (70) are installed on the vaporizer outlet tube sheet (11), and the vaporizer inlet tube sheet (12) and the vaporizer outlet tube sheet (11) are respectively hermetically connected to the inner wall of the shell side of the vaporizer (7); the lower end of the shell side of the vaporizer (7) is connected to a vaporizer inlet connection pipe (9) through an annular distributor.

2. The three-stage series heat exchanger according to claim 1, characterized in that, The lower surface of the inlet tube sheet (15) of the high-pressure steam generator is fixedly welded to the heat exchange tubes (141) of the high-pressure steam generator. The upper surface of the inlet tube sheet (15) of the high-pressure steam generator is provided with a heat insulation lining (151). The inlet tube sheet (15) of the high-pressure steam generator and the heat insulation lining (151) are penetrated with installation holes, and a medium distribution tube (142) is fixed in the installation holes. The lower end of the medium distribution tube (142) is fixedly inserted inside the heat exchange tubes (141) of the high-pressure steam generator. The upper end of the medium distribution tube (142) extends to the area between the heat insulation lining (151) and the outlet tube sheet (16) of the superheater. A cover (144) is installed at the upper end of the medium distribution tube (142), and distribution holes (143) are formed on the side surface of the upper end of the medium distribution tube (142).

3. A three-stage series heat exchanger according to claim 1, characterized in that, the annular distributor includes an outer cylinder (71) fixedly sleeved on the outer side of the shell side of the vaporizer (7). Two vaporizer inlet nozzles (9) are symmetrically installed on the side surface of the outer cylinder (71). There is an annular area between the outer cylinder (71) and the outer side of the shell side of the vaporizer (7). The area of the annular area close to the two vaporizer inlet nozzles (9) is a fluid diffusion area (72), and the area between the two fluid diffusion areas (72) is a flow guiding area (73). A plurality of distribution grooves (75) are formed at the position of the outer wall of the shell side of the vaporizer (7) corresponding to the flow guiding area (73); a spoiler (74) is provided between the fluid diffusion area (72) and the flow guiding area (73).

4. A three-stage series heat exchanger according to claim 1, characterized in that, a plurality of baffle plates (8) are installed on the inner wall of the shell side of the superheater (3) and the inner wall of the shell side of the vaporizer (7); sealing strips (81) are installed on the baffle plates (8) located inside the shell side of the superheater (3) through bolts (82), and sealing strips (81) are also installed on the baffle plates (8) located inside the shell side of the vaporizer (7) through bolts (82).

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