Tube heat exchanger and industrial heat exchange system

Abstract

The utility model discloses a tube heat exchanger and an industrial heat exchange system. The tube heat exchanger comprises a shell, an upper tube box, a lower tube box, a heat exchange tube, a shell pass inlet, a shell pass outlet, a tube pass inlet, a tube pass outlet and an overflow tube. The upper tube box and the lower tube box are arranged at the two ends of the shell respectively, an upper tube plate is arranged between the upper tube box and the shell, and a lower tube plate is arranged between the lower tube box and the shell. The heat exchange tube is arranged in the shell, and the two ends of the heat exchange tube are connected with the upper tube plate and the lower tube plate respectively. The shell pass inlet and the shell pass outlet are formed in the two sides of the shell correspondingly. The tube pass inlet and the tube pass outlet are respectively arranged on the lower tube box and the upper tube box; the lower end of the overflow pipe is connected with the heat exchange pipe, and the upper end of the overflow pipe is higher than the lowest surface of the tube pass outlet. By designing the overflow structure, the pipe heat exchanger can effectively control backflow of condensed liquid, so that waste of heat energy of the pipe heat exchanger is avoided, and the evaporation efficiency of equipment is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to heat exchange technical field especially relates to a tube heat exchanger and industrial heat exchange system. BACKGROUND

[0002] As the core equipment of coal chemical gasification and synthesis device, large reboiler is also the more core equipment of production ethylene, methanol, propylene, olefin, polysilicon monomer, petroleum chemical cracking unit, catalytic unit, synthesis unit and refining unit.

[0003] With the continuous improvement of equipment device capacity, high pressure device is also increasing, especially large reboiler, its use in multiple chemical industry is also increasing rapidly.

[0004] At present, there is a certain heat exchange problem in the reboiler running, because the large diameter heat exchange tube is not reasonably arranged, the low temperature material evaporated is easy to be affected by the condensation of the upper tube box and cause liquid backflow, and the backflow liquid can absorb the heat of high temperature medium, resulting in low evaporation efficiency.

[0005] Therefore, it is urgent to design a reboiler with more reasonable structure. INVENTION CONTENTS

[0006] The utility model discloses a tube heat exchanger and industrial heat exchange system, prevent the liquid backflow of condensation through the design overflow pipe in the upper tube box, avoid the waste of heat energy of middle boiler / reboiler, thereby improve evaporation efficiency.

[0007] The utility model discloses a tube heat exchanger and industrial heat exchange system, prevent the liquid backflow of condensation through the design overflow pipe in the upper tube box, avoid the waste of heat energy of middle boiler / reboiler, thereby improve evaporation efficiency.

[0008] A tube heat exchanger, including shell, upper tube box, lower tube box, heat exchange tube, shell inlet, shell outlet, tube inlet, tube outlet and overflow pipe.

[0009] Wherein, upper and lower tube box are arranged at both ends of the shell respectively, and upper tube plate is arranged between the upper tube box and the shell, and lower tube plate is arranged between the lower tube box and the shell;

[0010] Heat exchange tube is arranged in the shell, and both ends of the heat exchange tube are connected with the upper and lower tube plates respectively;

[0011] Shell inlet and shell outlet are arranged on both sides of the shell respectively;

[0012] Tube inlet and tube outlet are arranged on the lower tube box and the upper tube box respectively;

[0013] An overflow pipe is arranged in the upper pipe box, and a lower end of the overflow pipe is connected with the heat exchange pipe, and an upper end of the overflow pipe is higher than the lowest surface of the pipe passage outlet.

[0014] In some embodiments, the lower end of the overflow pipe is fixed with the upper end of the heat exchange pipe by deep hole welding.

[0015] In some embodiments, the upper end of the overflow pipe is lower than the highest surface of the pipe passage outlet.

[0016] In some embodiments, a height difference L between the upper end of the overflow pipe and the lowest surface of the pipe passage outlet accounts for 1 / 8-1 / 6 of a diameter of the pipe passage outlet.

[0017] In some embodiments, the tube heat exchanger further comprises a temperature control system arranged at a top of the heat exchange pipe, for detecting a real-time temperature of the first medium when the first medium reaches the upper tube plate.

[0018] In some embodiments, the tube heat exchanger further comprises an inlet pump connected with the shell passage inlet and associated with the temperature control system, for adjusting an entering amount of the second medium into the shell passage inlet according to a signal fed back by the temperature control system.

[0019] In some embodiments, baffles are arranged on the heat exchange pipe, for guiding the second medium to flow from the shell passage inlet to the shell passage outlet.

[0020] In some embodiments, a pressure relief valve communicating with the atmosphere is arranged on the upper tube plate and / or the lower tube plate.

[0021] In some embodiments, the tube heat exchanger is a middle boiler or a reboiler.

[0022] The utility model discloses further disclose an industrial heat exchange system which comprises the tube heat exchanger.

[0023] Compared with the prior art, the utility model has at least the following beneficial effects:

[0024] 1. By designing the overflow structure, the condensed liquid reflux can be effectively controlled, thereby avoiding the waste of heat energy of the tube heat exchanger, and the evaporation efficiency of the equipment is improved.

[0025] 2. By installing the temperature control system associated with the inlet pump, the entering amount of the high-temperature medium can be automatically adjusted, so that the temperature of the pipe passage outlet tends to be consistent, the same component is evaporated, impurities are prevented from entering the tower, the primary rough separation function is realized, and the subsequent tower operation is facilitated.

[0026] 3. The overflow pipe and the heat exchange pipe adopt the deep hole welding technology, which ensures the stability and reliability of the welding quality and improves the sealing performance under low-temperature working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a schematic diagram of the structure of the tube heat exchanger of the present application.

[0028] Figure 2 is a schematic diagram of the internal structure of the upper tube box.

[0029] Figure 3 is a schematic diagram of the connection structure of the overflow pipe and the heat dissipation pipe.

[0030] Figure 4 is a schematic diagram of the structure of the industrial heat exchange system of the present application.

[0031] Figure 5 is a schematic diagram of the structure of the existing large reboiler.

[0032] In the figure: 1, shell; 2, upper tube box; 3, lower tube box; 4, heat exchange tube; 5, shell side inlet; 6, shell side outlet; 7, tube side inlet; 8, tube side outlet; 9, overflow pipe; 10, upper tube plate; 11, lower tube plate; 12, temperature control system; 13, inlet pump; 14, baffle; 15, pressure relief valve. DETAILED DESCRIPTION

[0033] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations, however, can be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and fully convey the inventive aspects of example implementations to those skilled in the art. Like reference numerals refer to like elements throughout the figures, and descriptions of the same elements will not be repeated.

[0034] The words expressing position and direction described in the present application are explained by taking the drawings as an example, but changes can also be made as needed, and the changes made are included in the protection scope of the present application.

[0035] Referring to Figure 5 shown, Figure 5 is a schematic diagram of the structure of the existing large reboiler, which includes a shell 1, an upper tube box 2, a lower tube box 3, a heat exchange tube 4, a shell side inlet 5, a shell side outlet 6, a tube side inlet 7, and a tube side outlet 8.

[0036] Among them, the shell 1 is a cylindrical structure with both ends open, the upper tube box 2 and the lower tube box 3 are respectively arranged at both ends of the shell 1, and the upper tube plate 10 is arranged between the upper tube box 2 and the shell 1, and the lower tube plate 11 is arranged between the lower tube box 3 and the shell 1.

[0037] The heat exchange tube 4 is arranged in the shell 1, and the two ends thereof are connected with the upper tube plate 10 and the lower tube plate 11 respectively. Specifically, the upper end of the heat exchange tube 4 penetrates the upper tube plate 10 and is slightly higher than the plate surface by a certain distance, and the tube body is continuously welded with the upper tube plate 10 to ensure good sealing and fixing effect, and the lower end of the heat exchange tube 4 is also the same.

[0038] The shell side inlet 5 and the shell side outlet 6 are arranged on the two sides of the shell 1 respectively, so that the high-temperature (for example, -65 DEG C) second medium is input to the shell side for heat exchange with the heat exchange tube 4.

[0039] The tube side inlet 7 is arranged on the lower tube box 3, and is also connected with the material outlet of the tower (for example, a degassing tower or a rectifying tower); and the tube side outlet 8 is arranged on the upper tube box 2, and is also connected with the material inlet of the tower, so that the low-temperature (for example, -85 DEG C) first medium is input to the tube side.

[0040] As shown in Figure 4 , in the working process of the large reboiler, the material outlet of the tower inputs the low-temperature second medium to the lower tube box 3 through the tube side inlet 7, the second medium enters the heat exchange tube 4, at the same time, the high-temperature first medium is input to the shell side through the shell side inlet 5, the first medium is washed in the shell side, and the heat exchange is carried out between the first medium and the second medium in the heat exchange tube 4, so that the second medium is evaporated in the heat exchange tube 4, the evaporated second medium enters the upper tube box 2, and then enters the tower through the tube side outlet 8 to be separated, and the whole process is completed.

[0041] However, in the actual working process, the evaporated first medium contacts the top space of the upper tube box 2, so that part of the gas condenses and liquefies and flows back to the upper tube plate 10, and in addition, the upper end of the heat exchange tube 4 is basically flat or slightly higher than the plate surface of the upper tube plate 10, so that the condensed liquid flows back to the heat exchange tube 4 to absorb heat again, thereby reducing the working efficiency of the reboiler.

[0042] Therefore, the utility model discloses a novel tube heat exchanger, as shown in Figures 1 to 3 , the tube heat exchanger can be a middle boiler or a reboiler, which also comprises a shell 1, an upper tube box 2, a lower tube box 3, a heat exchange tube 4, a shell side inlet 5, a shell side outlet 6, a tube side inlet 7 and a tube side outlet 8, and the structure principle is similar to that of the large reboiler shown in Figure 5 , and will not be repeated here. The difference lies in that in the present application, the tube side outlet 8 of the upper tube box 2 is arranged transversely, and in addition, an overflow pipe 9 is additionally arranged.

[0043] As shown in Figure 2 and Figure 3 , the overflow pipe 9 is arranged in the upper tube box 2, the lower end of the overflow pipe 9 is connected with the heat exchange tube 4, and the upper end is higher than the lowest surface of the tube side outlet 8.

[0044] This design can effectively control the condensate backflow, thereby avoiding the waste of heat energy of the tube heat exchanger, and improving the efficiency of the equipment. Specifically, after the evaporated first medium contacts the top space of the upper tube box 2, part of the gas condenses and liquefies backflow to the upper tube plate 10. However, since the upper end of the heat exchange tube 4 is connected with the overflow pipe 9, the upper end port of the heat exchange tube 4 is virtually raised, and the condensed liquid cannot continue to be absorbed by backflow through the heat exchange tube 4, but can only accumulate on the upper tube plate 10. Moreover, since the upper end of the overflow pipe 9 is higher than the lowest surface of the tube pass outlet 8, when the condensed liquid accumulates to the level of the lowest surface of the tube pass outlet 8, it can flow into the tower from the tube pass outlet 8 for further separation.

[0045] Tests show that, under the same heat exchange conditions, the tube heat exchanger of the present application can improve the evaporation efficiency of the tube heat exchanger by 5%-10% compared with the existing reboiler of the same scale.

[0046] Since the above-mentioned tube heat exchanger is mainly used in low-temperature working conditions, if only ordinary welding is used, the connection between the lower end of the overflow pipe 9 and the upper end of the heat exchange tube 4 is prone to sealing leakage. Therefore, as shown in Figure 3 in a preferred embodiment, the lower end of the overflow pipe 9 and the upper end of the heat exchange tube 4 are fixed by deep hole welding, so as to ensure the stability and reliability of the welding quality and improve the sealing performance in low-temperature working conditions.

[0047] As shown in Figure 3 in some embodiments, the upper end of the overflow pipe 9 is lower than the highest surface of the tube pass outlet 8, so as to ensure that both gas and liquid can flow from the tube pass outlet 8 to the tower for separation, and avoid the safety hazard caused by excessive pressure of the upper tube box 2.

[0048] For example, the height difference between the upper end of the overflow pipe 9 and the lowest surface of the tube pass outlet 8 is 1 / 8-1 / 6 of the diameter of the tube pass outlet 8, preferably 1 / 7-1 / 6.

[0049] As shown in Figure 1 the tube heat exchanger of the present application further comprises a temperature control system 12. The temperature control system 12 comprises a temperature measuring thermocouple installed at the top of the heat exchange tube 4. The temperature measuring thermocouple can detect the real-time temperature of the first medium when it reaches the upper tube plate 10, and by adjusting different evaporation temperatures, different products such as ethylene, methanol, propylene, etc. can be obtained.

[0050] Further, the tube heat exchanger further comprises an inlet pump 13. The inlet pump 13 is connected to the shell inlet 5 and is signal-associated with the temperature control system 12, which can adjust the entering amount of the second medium into the shell inlet 5 according to the signal fed back by the temperature control system 12, repeatedly adjust continuously until the temperature of the tube outlet 8 tends to be consistent, so that the same component is evaporated, the impurities (different components evaporated) are prevented from entering the tower, the function of primary rough separation is realized, and the subsequent tower operation is facilitated. After detecting, the separation efficiency of the tube heat exchanger with the inlet pump 13 equipped with the temperature control system 12 can be improved by 5%-8% compared with before.

[0051] Referring to Figure 1 As shown in the drawings, in some embodiments, the baffle 14 is arranged on the heat exchange tube 4, which is used to guide the second medium to flow from the shell inlet 5 to the shell outlet 6, thereby prolonging the flow path length of the first medium in the shell and reducing the dead zone, which helps to improve the heat exchange effect. On the other hand, the baffle 14 can also support the heat exchange tube 4 to ensure that it remains stable during operation.

[0052] In some embodiments, the upper tube plate 10 and / or the lower tube plate 11 are provided with a pressure relief valve 15 communicating with the atmosphere. The pressure relief valve 15 is used to prevent the internal pressure of the equipment from being too high, to ensure the safe operation of the equipment, thereby extending the service life of the equipment. Preferably, the upper tube plate 10 and the lower tube plate 11 are both provided with the pressure relief valve 15.

[0053] Referring to Figure 4 As shown in the drawings, the utility model further discloses an industrial heat exchange system, which comprises the tube heat exchanger.

[0054] In the system, the tube inlet 7 of the tube heat exchanger can be connected with the material outlet at the bottom of the degassing tower or the rectifying tower, and the tube outlet 8 can be connected with the material inlet at the middle of the degassing tower or the rectifying tower, so that the low-temperature medium discharged from the degassing tower or the rectifying tower is subjected to evaporation treatment.

[0055] Although the embodiments of the utility model have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the utility model, and the ordinary skilled in the art can change, modify, replace and transform the above-mentioned embodiments within the scope of the utility model without departing from the principles and purposes of the utility model, and all these changes should belong to the protection scope of the utility model claim.

Claims

1. A tube heat exchanger, comprising: a shell (1); upper and lower tube boxes (2, 3) arranged at two ends of the shell (1) respectively, an upper tube plate (10) arranged between the upper tube box (2) and the shell (1), and a lower tube plate (11) arranged between the lower tube box (3) and the shell (1); a heat exchange tube (4) arranged in the shell (1), two ends of the heat exchange tube (4) being connected with the upper and lower tube plates (10, 11) respectively; a shell side inlet (5) and a shell side outlet (6) arranged on two sides of the shell (1) respectively; a tube side inlet (7) and a tube side outlet (8) arranged on the lower tube box (3) and the upper tube box (2) respectively; characterized in that further comprising: an overflow tube (9) arranged in the upper tube box (2), a lower end of the overflow tube (9) being connected with the heat exchange tube (4) and an upper end of the overflow tube (9) being higher than a lowest surface of the tube side outlet (8).

2. The tube heat exchanger according to claim 1, characterized in that The lower end of the overflow tube (9) is fixed with the upper end of the heat exchange tube (4) by deep hole welding.

3. The tube heat exchanger according to claim 1, characterized in that The upper end of the overflow tube (9) is lower than a highest surface of the tube side outlet (8).

4. The tube heat exchanger according to claim 3, characterized in that A height difference L of the upper end of the overflow tube (9) to the lowest surface of the tube side outlet (8) accounts for 1 / 8-1 / 6 of a diameter of the tube side outlet (8).

5. The tube heat exchanger according to claim 1, characterized in that Further comprising a temperature control system (12) arranged at a top of the heat exchange tube (4) for detecting a real-time temperature when a first medium reaches the upper tube plate (10).

6. The tube heat exchanger according to claim 5, characterized in that Further comprising an inlet pump (13) connected with the shell side inlet (5) and associated with the temperature control system (12) in signal, for adjusting an entering amount of a second medium into the shell side inlet (5) according to a signal with feedback of the temperature control system (12).

7. The tube heat exchanger according to claim 1, characterized in that A baffle (14) is arranged on the heat exchange tube (4) for guiding the second medium to flow from the shell side inlet (5) to the shell side outlet (6).

8. The tube heat exchanger according to claim 1, characterized in that A pressure relief valve (15) communicating with atmosphere is arranged on the upper tube plate (10) and / or the lower tube plate (11).

9. The tube heat exchanger according to claim 1, characterized in that The tube heat exchanger is a middle boiler or a reboiler.

10. An industrial heat exchange system, characterized in that, The tube heat exchanger according to any one of claims 1-9.

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