Double-layer vacuum tube plate and corrosion-resistant tubular heat exchanger

Abstract

The utility model discloses a double-layer vacuum tube plate and a corrosion-resistant tubular heat exchanger, the heat exchanger is provided with a shell and a heat exchange assembly, and the heat exchange assembly comprises a plurality of heat exchange tubes arranged between two tube plate bodies. The tube plate body comprises a middle cylinder, an inner tube plate and an outer tube plate, the inner tube plate and the outer tube plate are located at the two ends of the middle cylinder, a closed cavity is formed among the middle cylinder, the inner tube plate and the outer tube plate, a vacuumizing opening is formed in the middle cylinder, a fixing sleeve for a heat exchange tube to penetrate through is arranged on the tube plate body, and the fixing sleeve is connected with the inner tube plate and the outer tube plate in a sealed mode. And the heat exchange tube and the fixed sleeve are sealed through a sealing ring. The heat exchanger is provided with the tube plate body with the vacuum cavity, and the vacuum cavity can prevent low-temperature media in the cooling medium insulation tube box from influencing the inner tube plate, so that the inner tube plate forms a low-temperature area, and dew point corrosion is generated on the side, facing smoke, of the inner tube plate.

Description

Technical Field

[0001] The utility model relates to the technical field of heat exchange equipment, in particular to a double-layer vacuum tube plate and a corrosion-resistant tube heat exchanger. Background Art

[0002] Heat exchangers are devices that transfer part of the heat of hot fluids to cold fluids. They play an important role in industrial production such as metallurgy, chemical industry, petroleum, and power. In tubular heat exchangers, both ends of the heat exchange tubes are generally fixed and sealed with tube sheets. However, when existing tubular heat exchangers process flue gases containing corrosive components, they often face the problem of dew point corrosion of the tube sheets. In flue gas dew point corrosion, SO2 and SO3, or Cl ions are generated in the flue gas. When the wall temperature of the heating surface is lower than the flue gas dew point temperature, sulfuric acid / hydrochloric acid vapor will condense on the heating surface into a liquid containing sulfuric acid / hydrochloric acid, causing serious corrosion to the heating surface. This type of corrosion mainly occurs on the heating surface with a lower temperature, so it is also called low-temperature dew point corrosion.

[0003] When treating corrosive flue gas, the temperature of the corrosive flue gas to be heat exchanged is 270-300℃, while the temperature of the cooling medium is 20-50℃. Therefore, the tube sheet at one end of the cooling medium inlet has low-temperature cooling medium on one side and high-temperature flue gas on the other side. Due to the influence of the cooling medium, the inner side of the tube sheet is prone to low-temperature corrosion. Utility Model Content

[0004] The utility model aims to solve the technical problem that the inner side of the tube sheet at one end of the cooling medium inlet of the existing heat exchanger is prone to low-temperature corrosion, and provides a double-layer vacuum tube sheet and a corrosion-resistant tube heat exchanger.

[0005] In order to solve the deficiencies of the above technical problems, the utility model adopts the following technical solutions: a double-layer vacuum tube sheet, comprising a tube sheet body, the tube sheet body comprising an intermediate tube and inner tube sheets and outer tube sheets located at both ends thereof, a closed cavity is formed between the intermediate tube and the inner tube sheets and the outer tube sheets, a vacuum port is provided on the intermediate tube, a fixed sleeve for the heat exchange tube to pass through is provided on the tube sheet body, the fixed sleeve is sealedly connected to the inner tube sheet and the outer tube sheet, and the heat exchange tube and the fixed sleeve are sealed by a sealing ring.

[0006] As a further optimization of the double-layer vacuum tube plate of the utility model: a vacuum pressure gauge is provided at the vacuum port.

[0007] As a further optimization of the double-layer vacuum tube sheet of the utility model: the fixed sleeve is sealed and welded to the outer tube sheet and the inner tube sheet.

[0008] As a further optimization of the double-layer vacuum tube plate of the utility model: the inner wall of the fixed sleeve is provided with at least two annular grooves, and the sealing ring is embedded in the annular grooves.

[0009] The utility model also provides a corrosion-resistant tubular heat exchanger, which has:

[0010] A shell, wherein a cooling medium inlet pipe box and a cooling medium outlet pipe box are respectively arranged at two axial ends thereof, a tube sheet body is arranged between the shell and the cooling medium inlet pipe box and the cooling medium outlet pipe box, and a smoke inlet pipe box and a smoke outlet pipe box are respectively arranged in the circumference of the shell; and

[0011] A heat exchange assembly, comprising two tube sheets and a plurality of heat exchange tubes arranged between the two tube sheets;

[0012] A heat-insulating sleeve is arranged in the heat-exchange pipe close to the smoke outlet pipe box, and the heat-insulating sleeve is arranged at the end of the heat-exchange pipe.

[0013] As a further optimization of the corrosion-resistant tubular heat exchanger of the utility model: when the cooling medium is water, the material of the inner tube sheet is selected to be 316L or 2205 stainless steel, and the material of the outer tube sheet is selected to be carbon steel.

[0014] As a further optimization of the corrosion-resistant tubular heat exchanger of the utility model: when the cooling medium is desulfurized flue gas, the material of the inner tube sheet is 2205 stainless steel, and the material of the outer tube sheet is 316L stainless steel.

[0015] As a further optimization of the corrosion-resistant tubular heat exchanger of the utility model: a fixing ring is arranged at the inner end of the heat-insulating sleeve, and a gap is arranged between the outer wall of the heat-insulating sleeve and the inner wall of the heat-exchange tube.

[0016] As a further optimization of the corrosion-resistant tubular heat exchanger of the utility model: the material of the thermal insulation sleeve is polytetrafluoroethylene.

[0017] As a further optimization of the corrosion-resistant tubular heat exchanger of the utility model: the heat exchange tube is made of quartz glass or high borosilicate glass, and an anti-vibration partition is also arranged inside the shell.

[0018] The utility model has the following beneficial effects:

[0019] 1. The tube sheet of the utility model has a vacuum cavity. The vacuum cavity can prevent the low-temperature medium in the cooling medium tube box from affecting the inner tube sheet, so that a low-temperature area is formed on the inner tube sheet, thereby causing dew point corrosion on the side of the inner tube sheet facing the flue gas;

[0020] 2. The heat exchanger of the utility model is provided with a heat insulating sleeve in the heat exchange tube near the flue gas outlet, which can prevent condensation from forming outside the tube close to the tube sheet, and further reduce the occurrence of dew point corrosion of the tube sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is a schematic diagram of the internal structure of the tubular heat exchanger of the utility model;

[0022] Figure 2 for Figure 1 A local enlarged schematic diagram of the middle A;

[0023] Figure 3 for Figure 1 A partial enlarged schematic diagram of point B in the middle;

[0024] Markings in the figure:

[0025] 1. Shell;

[0026] 101. Cooling medium inlet pipe box;

[0027] 102. Cooling medium outlet pipe box;

[0028] 103. Flue gas inlet pipe box;

[0029] 104. Smoke outlet pipe box;

[0030] 105. Guide plate;

[0031] 106. Acid discharge port;

[0032] 2. Tube sheet body;

[0033] 201, intermediate tube;

[0034] 202, inner tube sheet;

[0035] 203, outer tube plate;

[0036] 204, vacuum port;

[0037] 205, fixed casing;

[0038] 206, sealing ring;

[0039] 3. Heat exchange tube;

[0040] 4. Thermal insulation sleeve. DETAILED DESCRIPTION

[0041] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with embodiments, but the content of the present invention is not limited to the following embodiments.

[0042] like Figure 1-3 As shown, a corrosion-resistant tubular heat exchanger comprises a shell 1 and a heat exchange component.

[0043] A cooling medium inlet pipe box 101 and a cooling medium outlet pipe box 102 are respectively arranged at the axial ends of the shell 1, tube sheets are arranged between the shell 1 and the cooling medium inlet pipe box 101 and the cooling medium outlet pipe box 102, and a smoke inlet pipe box 103 and a smoke outlet pipe box 104 are respectively arranged in the circumferential direction of the shell 1.

[0044] A guide plate 105 is arranged in the smoke inlet pipe box 103 , a smoke outlet is arranged on the side wall of the smoke outlet pipe box 104 , and an acid discharge port 106 is arranged at the bottom of the smoke outlet pipe box 104 .

[0045] The heat exchange assembly includes a plurality of heat exchange tubes 3 arranged between two tube sheets. The heat exchange tubes 3 are made of quartz glass or high borosilicate glass. An anti-vibration partition is also arranged inside the shell 1. The tube sheet includes a tube sheet body 2. The tube sheet body 2 includes an intermediate tube 201 and an inner tube sheet 202 and an outer tube sheet 203 located at both ends thereof. A closed cavity is formed between the intermediate tube 201 and the inner tube sheet 202 and the outer tube sheet 203. It can be foreseen that the intermediate tube 201 and the inner tube sheet 202 and the outer tube sheet 203 can be sealed and connected by welding. After welding, a vacuum port 204 is arranged on the intermediate tube 201, and a vacuum pressure gauge is arranged at the vacuum port 204. A vacuum state can be formed in the sealed chamber through the vacuum port 204, and the vacuum pressure gauge is used to display the hollowness in the sealed chamber.

[0046] Regarding the material selection of the inner tube sheet 202 and the outer tube sheet 203, the following options may be considered:

[0047] When the cooling medium is water, the material of the inner tube sheet 202 is 316L or 2205 stainless steel, and the material of the outer tube sheet 203 is carbon steel.

[0048] When the cooling medium is desulfurized flue gas, the material of the inner tube sheet 202 is 2205 stainless steel, and the material of the outer tube sheet 203 is 316L stainless steel.

[0049] Since the heat exchanger tube sheet body structure of this patent is quite different from the tube sheet body structure of the heat exchanger in the prior art, the connection relationship between the heat exchange tube and the tube sheet body in this patent is adjusted as follows:

[0050] The tube sheet body 2 is provided with a fixed sleeve 205 for the heat exchange tube 3 to pass through. The fixed sleeve 205 is sealedly connected to the inner tube sheet 202 and the outer tube sheet 203. The heat exchange tube 3 and the fixed sleeve 205 are sealed by a sealing ring 206. In this embodiment, the inner wall of the fixed sleeve 205 is provided with two annular grooves, and the sealing ring 206 is embedded in the annular grooves. One sealing ring can be provided in one annular groove, or two sealing rings can be provided.

[0051] In order to avoid the generation of condensate outside the tube close to the tube sheet and further reduce the generation of dew point corrosion of the tube sheet, a heat insulation sleeve 4 is arranged in the heat exchange tube 3 close to the flue gas outlet pipe box 104, and the heat insulation sleeve 4 is arranged at the end of the heat exchange tube 3.

[0052] The inner end of the heat-insulating sleeve 4 is provided with a fixing ring, and a gap is provided between the outer wall of the heat-insulating sleeve 4 and the inner wall of the heat-exchanging tube 3. The material of the heat-insulating sleeve 4 is polytetrafluoroethylene.

[0053] The heat exchanger of the utility model is provided with a tube sheet with a vacuum cavity. The setting of the vacuum cavity can prevent the low-temperature medium in the cooling medium tube box from affecting the inner tube sheet, so that a low-temperature area is formed on the inner tube sheet, and dew point corrosion is generated on the side of the inner tube sheet facing the flue gas.

[0054] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various modifications or variations within the scope of the claims, which does not affect the essence of the present invention.

Claims

1. A double-layer vacuum tube sheet, comprising a tube sheet body (2), characterized in that: The tube sheet body (2) comprises an intermediate tube (201) and an inner tube sheet (202) and an outer tube sheet (203) located at both ends thereof; a closed cavity is formed between the intermediate tube (201) and the inner tube sheet (202) and the outer tube sheet (203); a vacuum port (204) is provided on the intermediate tube (201); a fixed sleeve (205) for the heat exchange tube (3) to pass through is provided on the tube sheet body (2); the fixed sleeve (205) and the inner tube sheet (202) and the outer tube sheet (203) are sealed and connected; the heat exchange tube (3) and the fixed sleeve (205) are sealed by a sealing ring (206).

2. A double-layer vacuum tube plate as claimed in claim 1, characterized in that: A vacuum pressure gauge is provided at the vacuum port (204).

3. A double-layer vacuum tube plate as claimed in claim 1, characterized in that: The fixed sleeve (205) is sealed and welded to the outer tube sheet (203) and the inner tube sheet (202).

4. A double-layer vacuum tube plate as claimed in claim 1, characterized in that: The inner wall of the fixed sleeve (205) is provided with at least two annular grooves, and the sealing ring (206) is embedded in the annular grooves.

5. A corrosion-resistant tubular heat exchanger, characterized in that: It has: A shell (1), wherein a cooling medium inlet pipe box (101) and a cooling medium outlet pipe box (102) are respectively arranged at two axial ends thereof, a tube sheet body (2) is arranged between the shell (1) and the cooling medium inlet pipe box (101) and the cooling medium outlet pipe box (102), and a smoke inlet pipe box (103) and a smoke outlet pipe box (104) are respectively arranged in the circumferential direction of the shell (1); and A heat exchange assembly, comprising two tube sheets according to claim 1 and a plurality of heat exchange tubes (3) arranged between the two tube sheets; A heat-insulating sleeve (4) is arranged inside the heat-exchange tube (3) near the smoke outlet pipe box (104), and the heat-insulating sleeve (4) is arranged at the end of the heat-exchange tube (3).

6. A corrosion-resistant tubular heat exchanger as claimed in claim 5, characterized in that: When the cooling medium is water, the material of the inner tube sheet (202) is 316L or 2205 stainless steel, and the material of the outer tube sheet (203) is carbon steel.

7. A corrosion-resistant tubular heat exchanger as claimed in claim 5, characterized in that: When the cooling medium is desulfurized flue gas, the material of the inner tube sheet (202) is 2205 stainless steel, and the material of the outer tube sheet (203) is 316L stainless steel.

8. The corrosion-resistant tubular heat exchanger according to claim 5, characterized in that: The inner end of the heat-insulating sleeve (4) is provided with a fixing ring, and a gap is provided between the outer wall of the heat-insulating sleeve (4) and the inner wall of the heat exchange tube (3).

9. The corrosion-resistant tubular heat exchanger according to claim 5, characterized in that: The material of the heat insulating sleeve (4) is polytetrafluoroethylene.

10. The corrosion-resistant tubular heat exchanger according to claim 5, characterized in that: The heat exchange tube (3) is made of quartz glass or high borosilicate glass, and an anti-vibration partition is also provided inside the shell (1).

Images