Combined tube pass corrosion-resistant U-shaped tube heat exchanger and heat exchange method thereof

Abstract

The invention discloses a combined tube pass corrosion-resistant U-shaped tube heat exchanger and a heat exchange method thereof.The heat exchanger comprises a center box body, a transverse partition plate and a vertical partition plate, the transverse partition plate and the vertical partition plate are arranged in the center box body, the vertical partition plate evenly divides the center box body into a left tube box and a right tube box, and the transverse partition plate divides the left tube box and the right tube box into an upper small box and a lower small box; the left side and the right side of the central box body are respectively connected with a left tube box shell and a right tube box shell; a plurality of U-shaped heat exchange tubes are arranged in the left tube box shell and the right tube box shell respectively, and openings in the two ends of each U-shaped heat exchange tube are connected with the upper small box and the lower small box on the side close to the U-shaped heat exchange tube respectively. Shell pass liquid inlet pipes and shell pass liquid outlet pipes are respectively arranged at the left ends and the right ends of the left tube box shell and the right tube box shell; and the shell pass liquid outlet pipe at the right end of the left tube box shell is connected with the shell pass liquid inlet pipe at the left end of the right tube box shell through a pipeline. According to the integrated heat exchanger, the design is more compact, the occupied space is small, the material and installation cost is reduced, the material of the shell does not have the corrosion resistance requirement, and therefore the equipment cost is remarkably reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchange equipment, and in particular to a combined tube-side corrosion-resistant U-tube heat exchanger and a heat exchange method thereof, which is applied to a super-subcritical oxidation reaction process of high-salt and high-concentration organic wastewater. Background Art

[0002] The heat exchanger is a very practical heat exchange equipment that can transfer the heat of hot fluid to cold fluid. It has a simple structure, convenient operation, and high heat transfer efficiency. It is widely used in many industrial productions such as chemical, petroleum, power, and food.

[0003] When using the supercritical water oxidation process to treat high-salt and high-concentration wastewater, the untreated cold raw material liquid and the hot reaction liquid after the supercritical oxidation reaction are used as the shell-side fluid and the tube-side fluid to exchange heat in the heat exchanger. Due to the corrosiveness of the high-salt and high-concentration wastewater and the reaction liquid after the supercritical water oxidation reaction, the components of the heat exchanger often need to use corrosion-resistant alloy materials (for example: zirconium alloy, titanium alloy, palladium alloy), which are expensive and not conducive to widespread use. Summary of the invention

[0004] In order to solve the problem of high cost of heat exchanger when treating high-salt and high-concentration wastewater by supercritical water oxidation process, the object of the present invention is to provide a combined tube-side corrosion-resistant U-tube heat exchanger and a heat exchange method thereof.

[0005] In order to achieve the above object, the specific scheme adopted by the present invention is as follows:

[0006] A combined tube-side corrosion-resistant U-tube heat exchanger, comprising a central box body and mutually intersecting transverse partitions and vertical partitions arranged inside the central box body, wherein the vertical partitions evenly divide the central box body into a left tube box and a right tube box, and the transverse partitions divide the left tube box and the right tube box into an upper small box and a lower small box, respectively, and the left and right sides of the central box body are connected to the left tube box shell and the right tube box shell, respectively;

[0007] A plurality of U-shaped heat exchange tubes with openings facing right are arranged in the left tube box shell, one end of the U-shaped heat exchange tube is opened to connect to the upper small box on the left, and the other end is opened to connect to the lower small box on the left; a plurality of U-shaped heat exchange tubes with openings facing left are arranged in the right tube box shell, one end of the U-shaped heat exchange tube is opened to connect to the upper small box on the right, and the other end is opened to connect to the lower small box on the right;

[0008] The bottom of the lower small box and the top of the upper small box of the left pipe box are respectively provided with a pipe-side liquid inlet and a pipe-side liquid outlet, and the top of the upper small box and the bottom of the lower small box of the right pipe box are respectively provided with a pipe-side liquid inlet and a pipe-side liquid outlet;

[0009] The left and right ends of the left and right tube box shells are respectively provided with a shell-side liquid inlet pipe and a shell-side liquid outlet pipe, and the shell-side liquid outlet pipe at the right end of the left tube box shell is connected to the shell-side liquid inlet pipe at the left end of the right tube box shell by a pipeline.

[0010] Furthermore, the center box body, transverse partition and vertical partition are made of corrosion-resistant metal alloy materials selected from zirconium alloy, titanium alloy or palladium alloy; the left pipe box shell and the right pipe box shell are made of carbon steel, stainless steel or aluminum alloy.

[0011] Furthermore, the U-shaped heat exchange tube is made of quartz glass tube material, with an inner diameter of 16mm±2mm and a wall thickness of 1.5-3mm; the side wall of the corresponding upper small box or lower small box is provided with an installation hole compatible with the U-shaped heat exchange tube port, and the U-shaped heat exchange tube port is inserted into the installation hole of the side wall of the corresponding upper small box or lower small box, and fixed and sealed by a high-temperature adhesive.

[0012] Furthermore, the left and right sides of the central box body are connected to the left pipe box shell and the right pipe box shell through flanges respectively.

[0013] Furthermore, a bearing base is provided at the bottom of the central box body, the left pipe box shell and the right pipe box shell.

[0014] Furthermore, baffles are arranged inside the left tube box shell and the right tube box shell, which are evenly distributed in an up-and-down staggered manner. The U-shaped heat exchange tube passes through the baffles. One end of the baffle is fixedly connected to the inner wall of the left tube box shell or the right tube box shell, and the other end is suspended.

[0015] The present invention also discloses a heat exchange method of a combined tube-side corrosion-resistant U-tube heat exchanger, wherein the heat exchanger is applied to indirect heat exchange in a super-subcritical oxidation reaction process of high-salt and high-concentration organic wastewater, wherein the cold raw material liquid to be treated, i.e., the high-salt and high-concentration organic wastewater, enters the lower small box of the left tube box from the tube-side liquid inlet below the left tube box, turns to flow to the upper tube layer through the lower tube side of the U-shaped heat exchange tube, absorbs the heat of the shell-side hot fluid in the shell of the left tube box, enters the upper small box of the left tube box, is discharged from the tube-side liquid outlet at the upper part of the left tube box, enters the super-subcritical water oxidation reaction tower, enters the upper small box of the right tube box from the tube-side liquid inlet above the right tube box after being treated by the super-subcritical water oxidation reaction, turns to flow to the lower tube layer through the upper tube side of the U-shaped heat exchange tube, transfers its own heat to the shell-side cold fluid in the shell of the right tube box, enters the lower small box of the right tube box, is discharged from the tube-side liquid outlet at the lower part of the right tube box, and is subsequently treated;

[0016] After the heat exchange medium is heated, it enters from the shell-side liquid inlet pipe at the left end of the left tube box shell, and after multiple deflections, it transfers its own heat to the cold raw material liquid in the U-shaped heat exchange tube, and then enters the shell-side liquid inlet pipe at the left end of the right tube box shell from the shell-side liquid outlet pipe at the right end of the left tube box shell. After multiple deflections, it absorbs the heat in the hot reaction liquid after the supersubcritical oxidation reaction in the U-shaped heat exchange tube, and is discharged from the shell-side liquid outlet pipe at the right end of the right tube box shell, and enters the shell-side liquid inlet pipe at the left end of the left tube box shell to complete the cycle.

[0017] Furthermore, the heat exchange medium is heat transfer oil or soft water.

[0018] Furthermore, pressure sensors are provided inside the U-shaped heat exchange tube, the left tube box shell and the right tube box shell, and the pressure difference inside and outside the U-shaped heat exchange tube is within its tolerance range by adjusting the feed flow rate of the fluid passing through each of them.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1) The device of the present application has a compact structure, and the integrated heat exchanger is more compact in design, taking up less space, which is particularly beneficial for applications with limited space.

[0021] 2) The device of the present application is light in weight, and the integrated heat exchanger is relatively light in weight, which is convenient for transportation and installation.

[0022] 3) Cost-effectiveness and easy maintenance: The integrated heat exchanger has better cost-effectiveness because it reduces material and installation costs. For the integrated heat exchanger, maintenance and inspection may be more convenient because all the heat exchange components are in one unit.

[0023] 4) Heat exchange is not directly performed between the untreated cold raw material liquid and the hot reaction liquid after the super-subcritical oxidation reaction, but indirect heat exchange is performed through a non-corrosive fluid (such as heat transfer oil, soft water) as a heat transfer medium. Among them, the corrosive cold raw material liquid or the hot reaction liquid after the super-subcritical oxidation reaction is used as the tube-side fluid, and the non-corrosive liquid with good heat transfer efficiency such as heat transfer oil and soft water is used as the shell-side fluid. The combined tube-side corrosion-resistant U-tube heat exchanger provided by the present invention introduces a non-corrosive fluid (such as heat transfer oil, soft water) as a heat transfer medium, has good tube-side corrosion resistance, can operate stably for a long time in the corrosive environment of high-salt and high-concentration organic wastewater, and because there is no corrosion resistance requirement for the shell material, the equipment cost is significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a front view of a combined tube-side corrosion-resistant U-tube heat exchanger of the present invention;

[0025] Figure 2It is a schematic diagram of the main cross-sectional structure of a combined tube-side corrosion-resistant U-tube heat exchanger of the present invention;

[0026] Figure 3 The invention discloses a side view cross-sectional structure diagram of a combined tube-pass corrosion-resistant U-tube heat exchanger. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0028] See also Figure 1-3 The present invention discloses a combined tube-side corrosion-resistant U-tube heat exchanger, comprising a central box body 8 and mutually intersecting transverse partitions 10 and vertical partitions 11 arranged inside the central box body 8. The vertical partitions 11 evenly divide the central box body 8 into a left tube box and a right tube box. The transverse partitions 10 divide the left tube box and the right tube box into an upper small box and a lower small box, respectively. The left and right sides of the central box body 8 are connected to a left tube box shell 1 and a right tube box shell 12 respectively through flanges 5.

[0029] A plurality of U-shaped heat exchange tubes 9 with openings facing right are arranged in the left tube box shell 1, one end of the U-shaped heat exchange tube 9 is opened to connect to the upper small box on the left, and the other end is opened to connect to the lower small box on the left; a plurality of U-shaped heat exchange tubes 9 with openings facing left are arranged in the right tube box shell 12, one end of the U-shaped heat exchange tube 9 is opened to connect to the upper small box on the right, and the other end is opened to connect to the lower small box on the right. Baffles 13 evenly distributed in an up-and-down staggered manner are arranged inside the left tube box shell 1 and the right tube box shell 12, and the U-shaped heat exchange tube 9 passes through the baffles 13, one end of the baffles 13 is fixedly connected to the inner wall of the left tube box shell 1 or the right tube box shell 12, and the other end is suspended.

[0030] The bottom of the lower small box and the top of the upper small box of the left tube box are respectively provided with a tube-side liquid inlet 6 and a tube-side liquid outlet 7, and the top of the upper small box and the bottom of the lower small box of the right tube box are respectively provided with a tube-side liquid inlet 6 and a tube-side liquid outlet 7. The left and right ends of the left tube box housing 1 and the right tube box housing 12 are respectively provided with a shell-side liquid inlet pipe 2 and a shell-side liquid outlet pipe 4, and the shell-side liquid outlet pipe 4 at the right end of the left tube box housing 1 is connected to the shell-side liquid inlet pipe 2 at the left end of the right tube box housing 12 by a pipeline.

[0031] The center box body 8, the transverse partition 10 and the vertical partition 11 of the present invention are made of corrosion-resistant metal alloy materials, such as zirconium alloy, titanium alloy or palladium alloy; the left pipe box shell 1 and the right pipe box shell 12 are made of carbon steel, stainless steel or aluminum alloy.

[0032] Comparison Figure 1-2 A bearing base 3 is provided at the bottom of the central box body 8 , the left pipe box housing 1 and the right pipe box housing 12 .

[0033] The working process of the combined tube-side corrosion-resistant U-tube heat exchanger of the present invention when treating high-salt and high-concentration wastewater in a supersubcritical water oxidation process is as follows: when in use, the device is placed in a suitable position, and the heat-conducting oil heated to a certain temperature is introduced from the shell-side liquid inlet pipe 2 at the left end of the left tube box shell 1. After multiple deflections, the heat of the heat-conducting oil is transferred to the cold raw material liquid in the U-shaped heat exchange tube from the shell-side liquid outlet pipe 4 at the right end of the left tube box shell 1. After multiple deflections, the heat in the hot reaction liquid after the supersubcritical oxidation reaction in the U-shaped heat exchange tube is absorbed, and then the heat is discharged from the shell-side liquid outlet pipe 4 at the right end of the right tube box shell 12, and the heat-conducting oil enters the shell-side liquid inlet pipe 2 at the left end of the left tube box shell 1 to complete the cycle.

[0034] The cold raw material liquid to be treated, i.e., high-salt and high-concentration organic wastewater, enters the lower small box of the left tube box from the tube side liquid inlet 6 at the bottom of the left tube box, turns to the upper tube layer through the lower tube side of the U-shaped heat exchange tube, and enters the upper small box of the left tube box after absorbing the heat of the heat transfer oil in the shell side of the left tube box shell 1, and is discharged from the tube side liquid outlet 7 at the upper part of the left tube box, and enters the super subcritical water oxidation reaction tower. After being treated by the super subcritical water oxidation reaction, it enters the upper small box of the right tube box from the tube side liquid inlet 6 at the top of the right tube box, turns to the lower tube layer through the upper tube side of the U-shaped heat exchange tube, and transfers its own heat to the heat transfer oil that has lost heat in the right tube box shell 12, and then enters the lower small box of the right tube box, and is discharged from the tube side liquid outlet 7 at the bottom of the right tube box for subsequent treatment.

[0035] By using conventional heat exchangers in the prior art, the cold raw material liquid to be processed and the hot reaction liquid after the super-subcritical oxidation reaction are directly exchanged through the heat exchanger, and both the tube side material and the shell side material need to use corrosion-resistant metal alloy materials, such as TC4 alloy.

[0036] By using the combined tube-side corrosion-resistant U-tube heat exchanger of the present invention, heat transfer oil or soft water can be used as the heat exchange medium for indirect heat exchange, and 316L stainless steel can be used as the shell-side material. The chemical composition of 316L stainless steel is: 15.56% Cr, 11.01% Ni, 1.82% Mo, and the balance is iron.

[0037] The U-shaped heat exchange tube 9 is made of quartz glass tube material, with an inner diameter of 16mm±2mm and a wall thickness of 1.5-3mm; the side wall of the corresponding upper small box or lower small box is provided with a mounting hole adapted to the port of the U-shaped heat exchange tube 9, and the port of the U-shaped heat exchange tube 9 is inserted into the mounting hole of the side wall of the corresponding upper small box or lower small box and fixed and sealed by a high-temperature adhesive.

[0038] Inorganic high-temperature adhesive can be used for the installation of quartz glass heat exchange tubes. For example, 400℃ high-temperature adhesive, which is a two-component high-temperature adhesive in the form of clay composed of modified high-temperature resin and high-temperature curing agent, is polymerized with ceramics, metals, etc. It has high bonding strength with materials such as metals and ceramics, has no shrinkage after curing, and has excellent waterproof, cold-resistant, corrosion-resistant, aging-resistant and high-temperature-resistant properties, and can withstand temperatures of 350℃ for a long time.

[0039] When the present invention uses high temperature glue YK-8969 to fix and seal the port of the U-shaped heat exchange tube 9 with the installation hole of the corresponding upper small box or lower small box side wall, the connection strength and sealing effect meet the use requirements during heat exchange.

[0040] A quartz glass tube with an outer diameter of 20 mm, an inner diameter of 16 mm, and a wall thickness of 2 mm is selected as the heat exchange tube.

[0041] Quartz glass tube pressure calculation:

[0042]

[0043] Where:

[0044] P: Withstand pressure (MPa);

[0045] σ: allowable stress (MPa);

[0046] δ: wall thickness (mm);

[0047] D: outer diameter (mm).

[0048] Generally speaking, the allowable stress range of quartz glass is between 50 and 100 MPa, and 50 MPa is taken here. Therefore, the pressure of a quartz glass tube with an outer diameter of 20 mm, an inner diameter of 16 mm, and a wall thickness of 2 mm is 10 MPa. During heat exchange, the pressure resistance requirement of the heat exchange tube is generally 4 MPa, which is lower than the pressure resistance of the quartz glass tube, so the quartz glass tube can be used as the heat exchange tube. In addition, the corrosion rate of the quartz glass tube at high temperature is very low, the thermal expansion coefficient is extremely small, and it can withstand drastic temperature changes.

[0049] The contents described in this specification are merely an enumeration of implementation forms of the inventive concept, and the protection scope of the present invention should not be regarded as being limited to the specific forms described in the embodiments.

Claims

1. A combined tube-side corrosion-resistant U-tube heat exchanger, characterized in that It comprises a central box (8) and mutually intersecting transverse partitions (10) and vertical partitions (11) arranged inside the central box, wherein the vertical partitions (11) evenly divide the central box (8) into a left pipe box and a right pipe box, and the transverse partitions (10) divide the left pipe box and the right pipe box into an upper small box and a lower small box respectively, and the left and right sides of the central box (8) are respectively connected to a left pipe box shell (1) and a right pipe box shell (12); A plurality of U-shaped heat exchange tubes (9) with openings facing right are arranged in the left tube box shell (1), one end of the U-shaped heat exchange tube (9) is opened to connect to the upper small box on the left side, and the other end of the U-shaped heat exchange tube (9) is opened to connect to the lower small box on the left side; a plurality of U-shaped heat exchange tubes (9) with openings facing left are arranged in the right tube box shell (12), one end of the U-shaped heat exchange tube (9) is opened to connect to the upper small box on the right side, and the other end of the U-shaped heat exchange tube (9) is opened to connect to the lower small box on the right side; The bottom of the lower small box and the top of the upper small box of the left pipe box are respectively provided with a pipe-side liquid inlet (6) and a pipe-side liquid outlet (7); the top of the upper small box and the bottom of the lower small box of the right pipe box are respectively provided with a pipe-side liquid inlet (6) and a pipe-side liquid outlet (7); A shell-side liquid inlet pipe (2) and a shell-side liquid outlet pipe (4) are respectively arranged at the left and right ends of the left tube box shell (1) and the right tube box shell (12); the shell-side liquid outlet pipe (4) at the right end of the left tube box shell (1) is connected to the shell-side liquid inlet pipe (2) at the left end of the right tube box shell (12) by a pipeline.

2. A combined tube-side corrosion-resistant U-tube heat exchanger as claimed in claim 1, characterized in that The central box body (8), the transverse partition (10) and the vertical partition (11) are made of a corrosion-resistant metal alloy material selected from a zirconium alloy, a titanium alloy or a palladium alloy; the left pipe box shell (1) and the right pipe box shell (12) are made of carbon steel, stainless steel or an aluminum alloy.

3. A combined tube-side corrosion-resistant U-tube heat exchanger as claimed in claim 1, characterized in that The U-shaped heat exchange tube (9) is made of quartz glass tube material, has an inner diameter of 16 mm ± 2 mm, and a wall thickness of 1.5-3 mm; the side wall of the corresponding upper small box or lower small box is provided with a mounting hole adapted to the port of the U-shaped heat exchange tube (9); the port of the U-shaped heat exchange tube (9) is inserted into the mounting hole of the side wall of the corresponding upper small box or lower small box, and is fixed and sealed by a high-temperature adhesive.

4. A combined tube-side corrosion-resistant U-tube heat exchanger as claimed in claim 1, characterized in that The left and right sides of the central box body (8) are respectively connected to the left pipe box shell (1) and the right pipe box shell (12) via flanges (5).

5. A combined tube-side corrosion-resistant U-tube heat exchanger as claimed in claim 1, characterized in that A bearing base (3) is provided at the bottom of the central box body (8), the left pipe box shell (1) and the right pipe box shell (12).

6. A combined tube-side corrosion-resistant U-tube heat exchanger as claimed in claim 1, characterized in that Baffles (13) are disposed inside the left tube box shell (1) and the right tube box shell (12) in an evenly distributed manner in an up-and-down staggered manner. The U-shaped heat exchange tube (9) passes through the baffles (13). One end of the baffle (13) is fixedly connected to the inner wall of the left tube box shell (1) or the right tube box shell (12), and the other end is suspended in the air.

7. A heat exchange method for a combined tube-side corrosion-resistant U-tube heat exchanger as claimed in claim 1, characterized in that The heat exchanger is used for indirect heat exchange in a super-subcritical oxidation reaction process of high-salt and high-concentration organic wastewater. The cold raw material liquid to be treated, i.e., the high-salt and high-concentration organic wastewater, enters the lower small box of the left tube box from the tube side liquid inlet (6) at the bottom of the left tube box, turns to flow to the upper tube layer through the lower tube side of the U-shaped heat exchange tube, absorbs the heat of the shell side hot fluid in the left tube box shell (1), enters the upper small box of the left tube box, is discharged from the tube side liquid outlet (7) at the upper part of the left tube box, enters the super-subcritical water oxidation reaction tower, and after being treated by the super-subcritical water oxidation reaction, enters the upper small box of the right tube box from the tube side liquid inlet (6) at the top of the right tube box, turns to flow to the lower tube layer through the upper tube side of the U-shaped heat exchange tube, transfers its own heat to the shell side cold fluid in the right tube box shell (12), enters the lower small box of the right tube box, and is discharged from the tube side liquid outlet (7) at the bottom of the right tube box for subsequent treatment. After the heat exchange medium is heated, it is introduced into the shell-side liquid inlet pipe (2) at the left end of the left tube box shell (1), and after multiple deflections, its own heat is transferred to the cold raw material liquid in the U-shaped heat exchange tube. Then, it enters the shell-side liquid inlet pipe (2) at the left end of the right tube box shell (12) from the shell-side liquid outlet pipe (4) at the right end of the left tube box shell (1), and after multiple deflections, it absorbs heat from the hot reaction liquid after the super-subcritical oxidation reaction in the U-shaped heat exchange tube. Then, it is discharged from the shell-side liquid outlet pipe (4) at the right end of the right tube box shell (12) and enters the shell-side liquid inlet pipe (2) at the left end of the left tube box shell (1), completing the cycle.

8. A heat exchange method for a combined tube-side corrosion-resistant U-tube heat exchanger as claimed in claim 7, characterized in that The heat exchange medium is heat transfer oil or soft water.

9. A heat exchange method for a combined tube-side corrosion-resistant U-tube heat exchanger as claimed in claim 7, characterized in that Pressure sensors are provided inside the U-shaped heat exchange tube (9), the left tube box shell (1) and the right tube box shell (12). By adjusting the feed flow rate of the fluid inside each of them, the pressure difference between the inside and outside of the U-shaped heat exchange tube (9) is within its tolerance range.

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